Break out into separate repo.

85 files changed, 23965 insertions, 0 deletions

diff --git a/src/androidTest/java/org/whispersystems/test/InMemoryAxolotlStore.java b/src/androidTest/java/org/whispersystems/test/InMemoryAxolotlStore.java
new file mode 100644
index 00000000..4e001865
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/InMemoryAxolotlStore.java
@@ -0,0 +1,115 @@
+package org.whispersystems.test;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.IdentityKeyPair;
+import org.whispersystems.libaxolotl.InvalidKeyIdException;
+import org.whispersystems.libaxolotl.state.AxolotlStore;
+import org.whispersystems.libaxolotl.state.PreKeyRecord;
+import org.whispersystems.libaxolotl.state.SessionRecord;
+import org.whispersystems.libaxolotl.state.SignedPreKeyRecord;
+
+import java.util.List;
+
+public class InMemoryAxolotlStore implements AxolotlStore {
+
+  private final InMemoryIdentityKeyStore  identityKeyStore  = new InMemoryIdentityKeyStore();
+  private final InMemoryPreKeyStore       preKeyStore       = new InMemoryPreKeyStore();
+  private final InMemorySessionStore      sessionStore      = new InMemorySessionStore();
+  private final InMemorySignedPreKeyStore signedPreKeyStore = new InMemorySignedPreKeyStore();
+
+
+  @Override
+  public IdentityKeyPair getIdentityKeyPair() {
+    return identityKeyStore.getIdentityKeyPair();
+  }
+
+  @Override
+  public int getLocalRegistrationId() {
+    return identityKeyStore.getLocalRegistrationId();
+  }
+
+  @Override
+  public void saveIdentity(long recipientId, IdentityKey identityKey) {
+    identityKeyStore.saveIdentity(recipientId, identityKey);
+  }
+
+  @Override
+  public boolean isTrustedIdentity(long recipientId, IdentityKey identityKey) {
+    return identityKeyStore.isTrustedIdentity(recipientId, identityKey);
+  }
+
+  @Override
+  public PreKeyRecord loadPreKey(int preKeyId) throws InvalidKeyIdException {
+    return preKeyStore.loadPreKey(preKeyId);
+  }
+
+  @Override
+  public void storePreKey(int preKeyId, PreKeyRecord record) {
+    preKeyStore.storePreKey(preKeyId, record);
+  }
+
+  @Override
+  public boolean containsPreKey(int preKeyId) {
+    return preKeyStore.containsPreKey(preKeyId);
+  }
+
+  @Override
+  public void removePreKey(int preKeyId) {
+    preKeyStore.removePreKey(preKeyId);
+  }
+
+  @Override
+  public SessionRecord loadSession(long recipientId, int deviceId) {
+    return sessionStore.loadSession(recipientId, deviceId);
+  }
+
+  @Override
+  public List<Integer> getSubDeviceSessions(long recipientId) {
+    return sessionStore.getSubDeviceSessions(recipientId);
+  }
+
+  @Override
+  public void storeSession(long recipientId, int deviceId, SessionRecord record) {
+    sessionStore.storeSession(recipientId, deviceId, record);
+  }
+
+  @Override
+  public boolean containsSession(long recipientId, int deviceId) {
+    return sessionStore.containsSession(recipientId, deviceId);
+  }
+
+  @Override
+  public void deleteSession(long recipientId, int deviceId) {
+    sessionStore.deleteSession(recipientId, deviceId);
+  }
+
+  @Override
+  public void deleteAllSessions(long recipientId) {
+    sessionStore.deleteAllSessions(recipientId);
+  }
+
+  @Override
+  public SignedPreKeyRecord loadSignedPreKey(int signedPreKeyId) throws InvalidKeyIdException {
+    return signedPreKeyStore.loadSignedPreKey(signedPreKeyId);
+  }
+
+  @Override
+  public List<SignedPreKeyRecord> loadSignedPreKeys() {
+    return signedPreKeyStore.loadSignedPreKeys();
+  }
+
+  @Override
+  public void storeSignedPreKey(int signedPreKeyId, SignedPreKeyRecord record) {
+    signedPreKeyStore.storeSignedPreKey(signedPreKeyId, record);
+  }
+
+  @Override
+  public boolean containsSignedPreKey(int signedPreKeyId) {
+    return signedPreKeyStore.containsSignedPreKey(signedPreKeyId);
+  }
+
+  @Override
+  public void removeSignedPreKey(int signedPreKeyId) {
+    signedPreKeyStore.removeSignedPreKey(signedPreKeyId);
+  }
+}
diff --git a/src/androidTest/java/org/whispersystems/test/InMemoryIdentityKeyStore.java b/src/androidTest/java/org/whispersystems/test/InMemoryIdentityKeyStore.java
new file mode 100644
index 00000000..8a2e1d8f
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/InMemoryIdentityKeyStore.java
@@ -0,0 +1,53 @@
+package org.whispersystems.test;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.IdentityKeyPair;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.state.IdentityKeyStore;
+
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.util.HashMap;
+import java.util.Map;
+
+public class InMemoryIdentityKeyStore implements IdentityKeyStore {
+
+  private final Map<Long, IdentityKey> trustedKeys = new HashMap<>();
+
+  private final IdentityKeyPair identityKeyPair;
+  private final int             localRegistrationId;
+
+  public InMemoryIdentityKeyStore() {
+    try {
+      ECKeyPair identityKeyPairKeys = Curve.generateKeyPair();
+
+      this.identityKeyPair = new IdentityKeyPair(new IdentityKey(identityKeyPairKeys.getPublicKey()),
+                                                 identityKeyPairKeys.getPrivateKey());
+      this.localRegistrationId = SecureRandom.getInstance("SHA1PRNG").nextInt(16380) + 1;
+    } catch (NoSuchAlgorithmException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  @Override
+  public IdentityKeyPair getIdentityKeyPair() {
+    return identityKeyPair;
+  }
+
+  @Override
+  public int getLocalRegistrationId() {
+    return localRegistrationId;
+  }
+
+  @Override
+  public void saveIdentity(long recipientId, IdentityKey identityKey) {
+    trustedKeys.put(recipientId, identityKey);
+  }
+
+  @Override
+  public boolean isTrustedIdentity(long recipientId, IdentityKey identityKey) {
+    IdentityKey trusted = trustedKeys.get(recipientId);
+    return (trusted == null || trusted.equals(identityKey));
+  }
+}
diff --git a/src/androidTest/java/org/whispersystems/test/InMemoryPreKeyStore.java b/src/androidTest/java/org/whispersystems/test/InMemoryPreKeyStore.java
new file mode 100644
index 00000000..7c3cea08
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/InMemoryPreKeyStore.java
@@ -0,0 +1,42 @@
+package org.whispersystems.test;
+
+import org.whispersystems.libaxolotl.InvalidKeyIdException;
+import org.whispersystems.libaxolotl.state.PreKeyRecord;
+import org.whispersystems.libaxolotl.state.PreKeyStore;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+public class InMemoryPreKeyStore implements PreKeyStore {
+
+  private final Map<Integer, byte[]> store = new HashMap<>();
+
+  @Override
+  public PreKeyRecord loadPreKey(int preKeyId) throws InvalidKeyIdException {
+    try {
+      if (!store.containsKey(preKeyId)) {
+        throw new InvalidKeyIdException("No such prekeyrecord!");
+      }
+
+      return new PreKeyRecord(store.get(preKeyId));
+    } catch (IOException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  @Override
+  public void storePreKey(int preKeyId, PreKeyRecord record) {
+    store.put(preKeyId, record.serialize());
+  }
+
+  @Override
+  public boolean containsPreKey(int preKeyId) {
+    return store.containsKey(preKeyId);
+  }
+
+  @Override
+  public void removePreKey(int preKeyId) {
+    store.remove(preKeyId);
+  }
+}
diff --git a/src/androidTest/java/org/whispersystems/test/InMemorySessionStore.java b/src/androidTest/java/org/whispersystems/test/InMemorySessionStore.java
new file mode 100644
index 00000000..0d148ab0
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/InMemorySessionStore.java
@@ -0,0 +1,68 @@
+package org.whispersystems.test;
+
+import org.whispersystems.libaxolotl.state.SessionRecord;
+import org.whispersystems.libaxolotl.state.SessionStore;
+import org.whispersystems.libaxolotl.util.Pair;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+public class InMemorySessionStore implements SessionStore {
+
+  private Map<Pair<Long, Integer>, byte[]> sessions = new HashMap<>();
+
+  public InMemorySessionStore() {}
+
+  @Override
+  public synchronized SessionRecord loadSession(long recipientId, int deviceId) {
+    try {
+      if (containsSession(recipientId, deviceId)) {
+        return new SessionRecord(sessions.get(new Pair<>(recipientId, deviceId)));
+      } else {
+        return new SessionRecord();
+      }
+    } catch (IOException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  @Override
+  public synchronized List<Integer> getSubDeviceSessions(long recipientId) {
+    List<Integer> deviceIds = new LinkedList<>();
+
+    for (Pair<Long, Integer> key : sessions.keySet()) {
+      if (key.first() == recipientId) {
+        deviceIds.add(key.second());
+      }
+    }
+
+    return deviceIds;
+  }
+
+  @Override
+  public synchronized void storeSession(long recipientId, int deviceId, SessionRecord record) {
+    sessions.put(new Pair<>(recipientId, deviceId), record.serialize());
+  }
+
+  @Override
+  public synchronized boolean containsSession(long recipientId, int deviceId) {
+    return sessions.containsKey(new Pair<>(recipientId, deviceId));
+  }
+
+  @Override
+  public synchronized void deleteSession(long recipientId, int deviceId) {
+    sessions.remove(new Pair<>(recipientId, deviceId));
+  }
+
+  @Override
+  public synchronized void deleteAllSessions(long recipientId) {
+    for (Pair<Long, Integer> key : sessions.keySet()) {
+      if (key.first() == recipientId) {
+        sessions.remove(key);
+      }
+    }
+  }
+}
diff --git a/src/androidTest/java/org/whispersystems/test/InMemorySignedPreKeyStore.java b/src/androidTest/java/org/whispersystems/test/InMemorySignedPreKeyStore.java
new file mode 100644
index 00000000..7449eece
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/InMemorySignedPreKeyStore.java
@@ -0,0 +1,59 @@
+package org.whispersystems.test;
+
+import org.whispersystems.libaxolotl.InvalidKeyIdException;
+import org.whispersystems.libaxolotl.state.SignedPreKeyRecord;
+import org.whispersystems.libaxolotl.state.SignedPreKeyStore;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+public class InMemorySignedPreKeyStore implements SignedPreKeyStore {
+
+  private final Map<Integer, byte[]> store = new HashMap<>();
+
+  @Override
+  public SignedPreKeyRecord loadSignedPreKey(int signedPreKeyId) throws InvalidKeyIdException {
+    try {
+      if (!store.containsKey(signedPreKeyId)) {
+        throw new InvalidKeyIdException("No such signedprekeyrecord! " + signedPreKeyId);
+      }
+
+      return new SignedPreKeyRecord(store.get(signedPreKeyId));
+    } catch (IOException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  @Override
+  public List<SignedPreKeyRecord> loadSignedPreKeys() {
+    try {
+      List<SignedPreKeyRecord> results = new LinkedList<>();
+
+      for (byte[] serialized : store.values()) {
+        results.add(new SignedPreKeyRecord(serialized));
+      }
+
+      return results;
+    } catch (IOException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  @Override
+  public void storeSignedPreKey(int signedPreKeyId, SignedPreKeyRecord record) {
+    store.put(signedPreKeyId, record.serialize());
+  }
+
+  @Override
+  public boolean containsSignedPreKey(int signedPreKeyId) {
+    return store.containsKey(signedPreKeyId);
+  }
+
+  @Override
+  public void removeSignedPreKey(int signedPreKeyId) {
+    store.remove(signedPreKeyId);
+  }
+}
diff --git a/src/androidTest/java/org/whispersystems/test/SessionBuilderTest.java b/src/androidTest/java/org/whispersystems/test/SessionBuilderTest.java
new file mode 100644
index 00000000..802f401d
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/SessionBuilderTest.java
@@ -0,0 +1,601 @@
+package org.whispersystems.test;
+
+import android.test.AndroidTestCase;
+
+import org.whispersystems.libaxolotl.DuplicateMessageException;
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.InvalidKeyIdException;
+import org.whispersystems.libaxolotl.InvalidMessageException;
+import org.whispersystems.libaxolotl.InvalidVersionException;
+import org.whispersystems.libaxolotl.LegacyMessageException;
+import org.whispersystems.libaxolotl.NoSessionException;
+import org.whispersystems.libaxolotl.SessionBuilder;
+import org.whispersystems.libaxolotl.SessionCipher;
+import org.whispersystems.libaxolotl.StaleKeyExchangeException;
+import org.whispersystems.libaxolotl.UntrustedIdentityException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.protocol.CiphertextMessage;
+import org.whispersystems.libaxolotl.protocol.KeyExchangeMessage;
+import org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage;
+import org.whispersystems.libaxolotl.protocol.WhisperMessage;
+import org.whispersystems.libaxolotl.state.AxolotlStore;
+import org.whispersystems.libaxolotl.state.IdentityKeyStore;
+import org.whispersystems.libaxolotl.state.PreKeyBundle;
+import org.whispersystems.libaxolotl.state.PreKeyRecord;
+import org.whispersystems.libaxolotl.state.SignedPreKeyRecord;
+import org.whispersystems.libaxolotl.util.Pair;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class SessionBuilderTest extends AndroidTestCase {
+
+  private static final long ALICE_RECIPIENT_ID = 5L;
+  private static final long BOB_RECIPIENT_ID   = 2L;
+
+  public void testBasicPreKeyV2()
+      throws InvalidKeyException, InvalidVersionException, InvalidMessageException, InvalidKeyIdException, DuplicateMessageException, LegacyMessageException, UntrustedIdentityException, NoSessionException {
+    AxolotlStore   aliceStore          = new InMemoryAxolotlStore();
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+
+    AxolotlStore bobStore      = new InMemoryAxolotlStore();
+    ECKeyPair    bobPreKeyPair = Curve.generateKeyPair();
+    PreKeyBundle bobPreKey     = new PreKeyBundle(bobStore.getLocalRegistrationId(), 1,
+                                                  31337, bobPreKeyPair.getPublicKey(),
+                                                  0, null, null,
+                                                  bobStore.getIdentityKeyPair().getPublicKey());
+
+    aliceSessionBuilder.process(bobPreKey);
+
+    assertTrue(aliceStore.containsSession(BOB_RECIPIENT_ID, 1));
+    assertTrue(aliceStore.loadSession(BOB_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 2);
+
+    String            originalMessage    = "L'homme est condamné à être libre";
+    SessionCipher     aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPIENT_ID, 1);
+    CiphertextMessage outgoingMessage    = aliceSessionCipher.encrypt(originalMessage.getBytes());
+
+    assertTrue(outgoingMessage.getType() == CiphertextMessage.PREKEY_TYPE);
+
+    PreKeyWhisperMessage incomingMessage = new PreKeyWhisperMessage(outgoingMessage.serialize());
+    bobStore.storePreKey(31337, new PreKeyRecord(bobPreKey.getPreKeyId(), bobPreKeyPair));
+
+    SessionCipher bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+    byte[]        plaintext        = bobSessionCipher.decrypt(incomingMessage);
+
+    assertTrue(bobStore.containsSession(ALICE_RECIPIENT_ID, 1));
+    assertTrue(bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 2);
+    assertTrue(originalMessage.equals(new String(plaintext)));
+
+    CiphertextMessage bobOutgoingMessage = bobSessionCipher.encrypt(originalMessage.getBytes());
+    assertTrue(bobOutgoingMessage.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] alicePlaintext = aliceSessionCipher.decrypt((WhisperMessage)bobOutgoingMessage);
+    assertTrue(new String(alicePlaintext).equals(originalMessage));
+
+    runInteraction(aliceStore, bobStore);
+
+    aliceStore          = new InMemoryAxolotlStore();
+    aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+    aliceSessionCipher  = new SessionCipher(aliceStore, BOB_RECIPIENT_ID, 1);
+
+    bobPreKeyPair = Curve.generateKeyPair();
+    bobPreKey = new PreKeyBundle(bobStore.getLocalRegistrationId(),
+                                 1, 31338, bobPreKeyPair.getPublicKey(),
+                                 0, null, null, bobStore.getIdentityKeyPair().getPublicKey());
+
+    bobStore.storePreKey(31338, new PreKeyRecord(bobPreKey.getPreKeyId(), bobPreKeyPair));
+    aliceSessionBuilder.process(bobPreKey);
+
+    outgoingMessage = aliceSessionCipher.encrypt(originalMessage.getBytes());
+
+    try {
+      bobSessionCipher.decrypt(new PreKeyWhisperMessage(outgoingMessage.serialize()));
+      throw new AssertionError("shouldn't be trusted!");
+    } catch (UntrustedIdentityException uie) {
+      bobStore.saveIdentity(ALICE_RECIPIENT_ID, new PreKeyWhisperMessage(outgoingMessage.serialize()).getIdentityKey());
+    }
+
+    plaintext = bobSessionCipher.decrypt(new PreKeyWhisperMessage(outgoingMessage.serialize()));
+
+    assertTrue(new String(plaintext).equals(originalMessage));
+
+    bobPreKey = new PreKeyBundle(bobStore.getLocalRegistrationId(), 1,
+                                 31337, Curve.generateKeyPair().getPublicKey(),
+                                 0, null, null,
+                                 aliceStore.getIdentityKeyPair().getPublicKey());
+
+    try {
+      aliceSessionBuilder.process(bobPreKey);
+      throw new AssertionError("shoulnd't be trusted!");
+    } catch (UntrustedIdentityException uie) {
+      // good
+    }
+  }
+
+  public void testBasicPreKeyV3()
+      throws InvalidKeyException, InvalidVersionException, InvalidMessageException, InvalidKeyIdException, DuplicateMessageException, LegacyMessageException, UntrustedIdentityException, NoSessionException {
+    AxolotlStore   aliceStore          = new InMemoryAxolotlStore();
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+
+    final AxolotlStore bobStore                 = new InMemoryAxolotlStore();
+          ECKeyPair    bobPreKeyPair            = Curve.generateKeyPair();
+          ECKeyPair    bobSignedPreKeyPair      = Curve.generateKeyPair();
+          byte[]       bobSignedPreKeySignature = Curve.calculateSignature(bobStore.getIdentityKeyPair().getPrivateKey(),
+                                                                           bobSignedPreKeyPair.getPublicKey().serialize());
+
+    PreKeyBundle bobPreKey = new PreKeyBundle(bobStore.getLocalRegistrationId(), 1,
+                                              31337, bobPreKeyPair.getPublicKey(),
+                                              22, bobSignedPreKeyPair.getPublicKey(),
+                                              bobSignedPreKeySignature,
+                                              bobStore.getIdentityKeyPair().getPublicKey());
+
+    aliceSessionBuilder.process(bobPreKey);
+
+    assertTrue(aliceStore.containsSession(BOB_RECIPIENT_ID, 1));
+    assertTrue(aliceStore.loadSession(BOB_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 3);
+
+    final String            originalMessage    = "L'homme est condamné à être libre";
+          SessionCipher     aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPIENT_ID, 1);
+          CiphertextMessage outgoingMessage    = aliceSessionCipher.encrypt(originalMessage.getBytes());
+
+    assertTrue(outgoingMessage.getType() == CiphertextMessage.PREKEY_TYPE);
+
+    PreKeyWhisperMessage incomingMessage = new PreKeyWhisperMessage(outgoingMessage.serialize());
+    bobStore.storePreKey(31337, new PreKeyRecord(bobPreKey.getPreKeyId(), bobPreKeyPair));
+    bobStore.storeSignedPreKey(22, new SignedPreKeyRecord(22, System.currentTimeMillis(), bobSignedPreKeyPair, bobSignedPreKeySignature));
+
+    SessionCipher bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+    byte[] plaintext = bobSessionCipher.decrypt(incomingMessage, new SessionCipher.DecryptionCallback() {
+      @Override
+      public void handlePlaintext(byte[] plaintext) {
+        assertTrue(originalMessage.equals(new String(plaintext)));
+        assertFalse(bobStore.containsSession(ALICE_RECIPIENT_ID, 1));
+      }
+    });
+
+    assertTrue(bobStore.containsSession(ALICE_RECIPIENT_ID, 1));
+    assertTrue(bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 3);
+    assertTrue(bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getAliceBaseKey() != null);
+    assertTrue(originalMessage.equals(new String(plaintext)));
+
+    CiphertextMessage bobOutgoingMessage = bobSessionCipher.encrypt(originalMessage.getBytes());
+    assertTrue(bobOutgoingMessage.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] alicePlaintext = aliceSessionCipher.decrypt(new WhisperMessage(bobOutgoingMessage.serialize()));
+    assertTrue(new String(alicePlaintext).equals(originalMessage));
+
+    runInteraction(aliceStore, bobStore);
+
+    aliceStore          = new InMemoryAxolotlStore();
+    aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+    aliceSessionCipher  = new SessionCipher(aliceStore, BOB_RECIPIENT_ID, 1);
+
+    bobPreKeyPair            = Curve.generateKeyPair();
+    bobSignedPreKeyPair      = Curve.generateKeyPair();
+    bobSignedPreKeySignature = Curve.calculateSignature(bobStore.getIdentityKeyPair().getPrivateKey(), bobSignedPreKeyPair.getPublicKey().serialize());
+    bobPreKey = new PreKeyBundle(bobStore.getLocalRegistrationId(),
+                                 1, 31338, bobPreKeyPair.getPublicKey(),
+                                 23, bobSignedPreKeyPair.getPublicKey(), bobSignedPreKeySignature,
+                                 bobStore.getIdentityKeyPair().getPublicKey());
+
+    bobStore.storePreKey(31338, new PreKeyRecord(bobPreKey.getPreKeyId(), bobPreKeyPair));
+    bobStore.storeSignedPreKey(23, new SignedPreKeyRecord(23, System.currentTimeMillis(), bobSignedPreKeyPair, bobSignedPreKeySignature));
+    aliceSessionBuilder.process(bobPreKey);
+
+    outgoingMessage = aliceSessionCipher.encrypt(originalMessage.getBytes());
+
+    try {
+      plaintext = bobSessionCipher.decrypt(new PreKeyWhisperMessage(outgoingMessage.serialize()));
+      throw new AssertionError("shouldn't be trusted!");
+    } catch (UntrustedIdentityException uie) {
+      bobStore.saveIdentity(ALICE_RECIPIENT_ID, new PreKeyWhisperMessage(outgoingMessage.serialize()).getIdentityKey());
+    }
+
+    plaintext = bobSessionCipher.decrypt(new PreKeyWhisperMessage(outgoingMessage.serialize()));
+    assertTrue(new String(plaintext).equals(originalMessage));
+
+    bobPreKey = new PreKeyBundle(bobStore.getLocalRegistrationId(), 1,
+                                 31337, Curve.generateKeyPair().getPublicKey(),
+                                 23, bobSignedPreKeyPair.getPublicKey(), bobSignedPreKeySignature,
+                                 aliceStore.getIdentityKeyPair().getPublicKey());
+
+    try {
+      aliceSessionBuilder.process(bobPreKey);
+      throw new AssertionError("shoulnd't be trusted!");
+    } catch (UntrustedIdentityException uie) {
+      // good
+    }
+  }
+
+  public void testBadSignedPreKeySignature() throws InvalidKeyException, UntrustedIdentityException {
+    AxolotlStore   aliceStore          = new InMemoryAxolotlStore();
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+
+    IdentityKeyStore bobIdentityKeyStore = new InMemoryIdentityKeyStore();
+
+    ECKeyPair bobPreKeyPair            = Curve.generateKeyPair();
+    ECKeyPair bobSignedPreKeyPair      = Curve.generateKeyPair();
+    byte[]    bobSignedPreKeySignature = Curve.calculateSignature(bobIdentityKeyStore.getIdentityKeyPair().getPrivateKey(),
+                                                                  bobSignedPreKeyPair.getPublicKey().serialize());
+
+
+    for (int i=0;i<bobSignedPreKeySignature.length * 8;i++) {
+      byte[] modifiedSignature = new byte[bobSignedPreKeySignature.length];
+      System.arraycopy(bobSignedPreKeySignature, 0, modifiedSignature, 0, modifiedSignature.length);
+
+      modifiedSignature[i/8] ^= (0x01 << (i % 8));
+
+      PreKeyBundle bobPreKey = new PreKeyBundle(bobIdentityKeyStore.getLocalRegistrationId(), 1,
+                                                31337, bobPreKeyPair.getPublicKey(),
+                                                22, bobSignedPreKeyPair.getPublicKey(), modifiedSignature,
+                                                bobIdentityKeyStore.getIdentityKeyPair().getPublicKey());
+
+      try {
+        aliceSessionBuilder.process(bobPreKey);
+        throw new AssertionError("Accepted modified device key signature!");
+      } catch (InvalidKeyException ike) {
+        // good
+      }
+    }
+
+    PreKeyBundle bobPreKey = new PreKeyBundle(bobIdentityKeyStore.getLocalRegistrationId(), 1,
+                                              31337, bobPreKeyPair.getPublicKey(),
+                                              22, bobSignedPreKeyPair.getPublicKey(), bobSignedPreKeySignature,
+                                              bobIdentityKeyStore.getIdentityKeyPair().getPublicKey());
+
+    aliceSessionBuilder.process(bobPreKey);
+  }
+
+  public void testRepeatBundleMessageV2() throws InvalidKeyException, UntrustedIdentityException, InvalidVersionException, InvalidMessageException, InvalidKeyIdException, DuplicateMessageException, LegacyMessageException, NoSessionException {
+    AxolotlStore   aliceStore          = new InMemoryAxolotlStore();
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+
+    AxolotlStore bobStore = new InMemoryAxolotlStore();
+
+    ECKeyPair bobPreKeyPair            = Curve.generateKeyPair();
+    ECKeyPair bobSignedPreKeyPair      = Curve.generateKeyPair();
+    byte[]    bobSignedPreKeySignature = Curve.calculateSignature(bobStore.getIdentityKeyPair().getPrivateKey(),
+                                                                  bobSignedPreKeyPair.getPublicKey().serialize());
+
+    PreKeyBundle bobPreKey = new PreKeyBundle(bobStore.getLocalRegistrationId(), 1,
+                                              31337, bobPreKeyPair.getPublicKey(),
+                                              0, null, null,
+                                              bobStore.getIdentityKeyPair().getPublicKey());
+
+    bobStore.storePreKey(31337, new PreKeyRecord(bobPreKey.getPreKeyId(), bobPreKeyPair));
+    bobStore.storeSignedPreKey(22, new SignedPreKeyRecord(22, System.currentTimeMillis(), bobSignedPreKeyPair, bobSignedPreKeySignature));
+
+    aliceSessionBuilder.process(bobPreKey);
+
+    String            originalMessage    = "L'homme est condamné à être libre";
+    SessionCipher     aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPIENT_ID, 1);
+    CiphertextMessage outgoingMessageOne = aliceSessionCipher.encrypt(originalMessage.getBytes());
+    CiphertextMessage outgoingMessageTwo = aliceSessionCipher.encrypt(originalMessage.getBytes());
+
+    assertTrue(outgoingMessageOne.getType() == CiphertextMessage.PREKEY_TYPE);
+
+    PreKeyWhisperMessage incomingMessage = new PreKeyWhisperMessage(outgoingMessageOne.serialize());
+
+    SessionCipher bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    byte[]        plaintext        = bobSessionCipher.decrypt(incomingMessage);
+    assertTrue(originalMessage.equals(new String(plaintext)));
+
+    CiphertextMessage bobOutgoingMessage = bobSessionCipher.encrypt(originalMessage.getBytes());
+
+    byte[] alicePlaintext = aliceSessionCipher.decrypt(new WhisperMessage(bobOutgoingMessage.serialize()));
+    assertTrue(originalMessage.equals(new String(alicePlaintext)));
+
+    // The test
+
+    PreKeyWhisperMessage incomingMessageTwo = new PreKeyWhisperMessage(outgoingMessageTwo.serialize());
+
+    plaintext = bobSessionCipher.decrypt(incomingMessageTwo);
+    assertTrue(originalMessage.equals(new String(plaintext)));
+
+    bobOutgoingMessage = bobSessionCipher.encrypt(originalMessage.getBytes());
+    alicePlaintext = aliceSessionCipher.decrypt(new WhisperMessage(bobOutgoingMessage.serialize()));
+    assertTrue(originalMessage.equals(new String(alicePlaintext)));
+
+  }
+
+  public void testRepeatBundleMessageV3() throws InvalidKeyException, UntrustedIdentityException, InvalidVersionException, InvalidMessageException, InvalidKeyIdException, DuplicateMessageException, LegacyMessageException, NoSessionException {
+    AxolotlStore   aliceStore          = new InMemoryAxolotlStore();
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+
+    AxolotlStore bobStore = new InMemoryAxolotlStore();
+
+    ECKeyPair bobPreKeyPair            = Curve.generateKeyPair();
+    ECKeyPair bobSignedPreKeyPair      = Curve.generateKeyPair();
+    byte[]    bobSignedPreKeySignature = Curve.calculateSignature(bobStore.getIdentityKeyPair().getPrivateKey(),
+                                                                  bobSignedPreKeyPair.getPublicKey().serialize());
+
+    PreKeyBundle bobPreKey = new PreKeyBundle(bobStore.getLocalRegistrationId(), 1,
+                                              31337, bobPreKeyPair.getPublicKey(),
+                                              22, bobSignedPreKeyPair.getPublicKey(), bobSignedPreKeySignature,
+                                              bobStore.getIdentityKeyPair().getPublicKey());
+
+    bobStore.storePreKey(31337, new PreKeyRecord(bobPreKey.getPreKeyId(), bobPreKeyPair));
+    bobStore.storeSignedPreKey(22, new SignedPreKeyRecord(22, System.currentTimeMillis(), bobSignedPreKeyPair, bobSignedPreKeySignature));
+
+    aliceSessionBuilder.process(bobPreKey);
+
+    String            originalMessage    = "L'homme est condamné à être libre";
+    SessionCipher     aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPIENT_ID, 1);
+    CiphertextMessage outgoingMessageOne = aliceSessionCipher.encrypt(originalMessage.getBytes());
+    CiphertextMessage outgoingMessageTwo = aliceSessionCipher.encrypt(originalMessage.getBytes());
+
+    assertTrue(outgoingMessageOne.getType() == CiphertextMessage.PREKEY_TYPE);
+    assertTrue(outgoingMessageTwo.getType() == CiphertextMessage.PREKEY_TYPE);
+
+    PreKeyWhisperMessage incomingMessage = new PreKeyWhisperMessage(outgoingMessageOne.serialize());
+
+    SessionCipher bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    byte[]        plaintext        = bobSessionCipher.decrypt(incomingMessage);
+    assertTrue(originalMessage.equals(new String(plaintext)));
+
+    CiphertextMessage bobOutgoingMessage = bobSessionCipher.encrypt(originalMessage.getBytes());
+
+    byte[] alicePlaintext = aliceSessionCipher.decrypt(new WhisperMessage(bobOutgoingMessage.serialize()));
+    assertTrue(originalMessage.equals(new String(alicePlaintext)));
+
+    // The test
+
+    PreKeyWhisperMessage incomingMessageTwo = new PreKeyWhisperMessage(outgoingMessageTwo.serialize());
+
+    plaintext = bobSessionCipher.decrypt(new PreKeyWhisperMessage(incomingMessageTwo.serialize()));
+    assertTrue(originalMessage.equals(new String(plaintext)));
+
+    bobOutgoingMessage = bobSessionCipher.encrypt(originalMessage.getBytes());
+    alicePlaintext = aliceSessionCipher.decrypt(new WhisperMessage(bobOutgoingMessage.serialize()));
+    assertTrue(originalMessage.equals(new String(alicePlaintext)));
+
+  }
+
+  public void testBadMessageBundle() throws InvalidKeyException, UntrustedIdentityException, InvalidVersionException, InvalidMessageException, DuplicateMessageException, LegacyMessageException, InvalidKeyIdException {
+    AxolotlStore   aliceStore          = new InMemoryAxolotlStore();
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+
+    AxolotlStore bobStore = new InMemoryAxolotlStore();
+
+    ECKeyPair bobPreKeyPair            = Curve.generateKeyPair();
+    ECKeyPair bobSignedPreKeyPair      = Curve.generateKeyPair();
+    byte[]    bobSignedPreKeySignature = Curve.calculateSignature(bobStore.getIdentityKeyPair().getPrivateKey(),
+                                                                  bobSignedPreKeyPair.getPublicKey().serialize());
+
+    PreKeyBundle bobPreKey = new PreKeyBundle(bobStore.getLocalRegistrationId(), 1,
+                                              31337, bobPreKeyPair.getPublicKey(),
+                                              22, bobSignedPreKeyPair.getPublicKey(), bobSignedPreKeySignature,
+                                              bobStore.getIdentityKeyPair().getPublicKey());
+
+    bobStore.storePreKey(31337, new PreKeyRecord(bobPreKey.getPreKeyId(), bobPreKeyPair));
+    bobStore.storeSignedPreKey(22, new SignedPreKeyRecord(22, System.currentTimeMillis(), bobSignedPreKeyPair, bobSignedPreKeySignature));
+
+    aliceSessionBuilder.process(bobPreKey);
+
+    String            originalMessage    = "L'homme est condamné à être libre";
+    SessionCipher     aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPIENT_ID, 1);
+    CiphertextMessage outgoingMessageOne = aliceSessionCipher.encrypt(originalMessage.getBytes());
+
+    assertTrue(outgoingMessageOne.getType() == CiphertextMessage.PREKEY_TYPE);
+
+    byte[] goodMessage = outgoingMessageOne.serialize();
+    byte[] badMessage  = new byte[goodMessage.length];
+    System.arraycopy(goodMessage, 0, badMessage, 0, badMessage.length);
+
+    badMessage[badMessage.length-10] ^= 0x01;
+
+    PreKeyWhisperMessage incomingMessage  = new PreKeyWhisperMessage(badMessage);
+    SessionCipher        bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    byte[] plaintext = new byte[0];
+
+    try {
+      plaintext = bobSessionCipher.decrypt(incomingMessage);
+      throw new AssertionError("Decrypt should have failed!");
+    } catch (InvalidMessageException e) {
+      // good.
+    }
+
+    assertTrue(bobStore.containsPreKey(31337));
+
+    plaintext = bobSessionCipher.decrypt(new PreKeyWhisperMessage(goodMessage));
+
+    assertTrue(originalMessage.equals(new String(plaintext)));
+    assertTrue(!bobStore.containsPreKey(31337));
+  }
+
+  public void testBasicKeyExchange() throws InvalidKeyException, LegacyMessageException, InvalidMessageException, DuplicateMessageException, UntrustedIdentityException, StaleKeyExchangeException, InvalidVersionException, NoSessionException {
+    AxolotlStore   aliceStore          = new InMemoryAxolotlStore();
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+
+    AxolotlStore   bobStore          = new InMemoryAxolotlStore();
+    SessionBuilder bobSessionBuilder = new SessionBuilder(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    KeyExchangeMessage aliceKeyExchangeMessage      = aliceSessionBuilder.process();
+    assertTrue(aliceKeyExchangeMessage != null);
+
+    byte[]             aliceKeyExchangeMessageBytes = aliceKeyExchangeMessage.serialize();
+    KeyExchangeMessage bobKeyExchangeMessage        = bobSessionBuilder.process(new KeyExchangeMessage(aliceKeyExchangeMessageBytes));
+
+    assertTrue(bobKeyExchangeMessage != null);
+
+    byte[]             bobKeyExchangeMessageBytes = bobKeyExchangeMessage.serialize();
+    KeyExchangeMessage response                   = aliceSessionBuilder.process(new KeyExchangeMessage(bobKeyExchangeMessageBytes));
+
+    assertTrue(response == null);
+    assertTrue(aliceStore.containsSession(BOB_RECIPIENT_ID, 1));
+    assertTrue(bobStore.containsSession(ALICE_RECIPIENT_ID, 1));
+
+    runInteraction(aliceStore, bobStore);
+
+    aliceStore              = new InMemoryAxolotlStore();
+    aliceSessionBuilder     = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+    aliceKeyExchangeMessage = aliceSessionBuilder.process();
+
+    try {
+      bobKeyExchangeMessage = bobSessionBuilder.process(aliceKeyExchangeMessage);
+      throw new AssertionError("This identity shouldn't be trusted!");
+    } catch (UntrustedIdentityException uie) {
+      bobStore.saveIdentity(ALICE_RECIPIENT_ID, aliceKeyExchangeMessage.getIdentityKey());
+      bobKeyExchangeMessage = bobSessionBuilder.process(aliceKeyExchangeMessage);
+    }
+
+    assertTrue(aliceSessionBuilder.process(bobKeyExchangeMessage) == null);
+
+    runInteraction(aliceStore, bobStore);
+  }
+
+  public void testSimultaneousKeyExchange()
+      throws InvalidKeyException, DuplicateMessageException, LegacyMessageException, InvalidMessageException, UntrustedIdentityException, StaleKeyExchangeException, NoSessionException {
+    AxolotlStore   aliceStore          = new InMemoryAxolotlStore();
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+
+    AxolotlStore   bobStore          = new InMemoryAxolotlStore();
+    SessionBuilder bobSessionBuilder = new SessionBuilder(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    KeyExchangeMessage aliceKeyExchange = aliceSessionBuilder.process();
+    KeyExchangeMessage bobKeyExchange   = bobSessionBuilder.process();
+
+    assertTrue(aliceKeyExchange != null);
+    assertTrue(bobKeyExchange != null);
+
+    KeyExchangeMessage aliceResponse = aliceSessionBuilder.process(bobKeyExchange);
+    KeyExchangeMessage bobResponse   = bobSessionBuilder.process(aliceKeyExchange);
+
+    assertTrue(aliceResponse != null);
+    assertTrue(bobResponse != null);
+
+    KeyExchangeMessage aliceAck = aliceSessionBuilder.process(bobResponse);
+    KeyExchangeMessage bobAck   = bobSessionBuilder.process(aliceResponse);
+
+    assertTrue(aliceAck == null);
+    assertTrue(bobAck == null);
+
+    runInteraction(aliceStore, bobStore);
+  }
+
+  public void testOptionalOneTimePreKey() throws Exception {
+    AxolotlStore   aliceStore          = new InMemoryAxolotlStore();
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPIENT_ID, 1);
+
+    AxolotlStore bobStore = new InMemoryAxolotlStore();
+
+    ECKeyPair bobPreKeyPair            = Curve.generateKeyPair();
+    ECKeyPair bobSignedPreKeyPair      = Curve.generateKeyPair();
+    byte[]    bobSignedPreKeySignature = Curve.calculateSignature(bobStore.getIdentityKeyPair().getPrivateKey(),
+                                                                  bobSignedPreKeyPair.getPublicKey().serialize());
+
+    PreKeyBundle bobPreKey = new PreKeyBundle(bobStore.getLocalRegistrationId(), 1,
+                                              0, null,
+                                              22, bobSignedPreKeyPair.getPublicKey(),
+                                              bobSignedPreKeySignature,
+                                              bobStore.getIdentityKeyPair().getPublicKey());
+
+    aliceSessionBuilder.process(bobPreKey);
+
+    assertTrue(aliceStore.containsSession(BOB_RECIPIENT_ID, 1));
+    assertTrue(aliceStore.loadSession(BOB_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 3);
+
+    String            originalMessage    = "L'homme est condamné à être libre";
+    SessionCipher     aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPIENT_ID, 1);
+    CiphertextMessage outgoingMessage    = aliceSessionCipher.encrypt(originalMessage.getBytes());
+
+    assertTrue(outgoingMessage.getType() == CiphertextMessage.PREKEY_TYPE);
+
+    PreKeyWhisperMessage incomingMessage = new PreKeyWhisperMessage(outgoingMessage.serialize());
+    assertTrue(!incomingMessage.getPreKeyId().isPresent());
+
+    bobStore.storePreKey(31337, new PreKeyRecord(bobPreKey.getPreKeyId(), bobPreKeyPair));
+    bobStore.storeSignedPreKey(22, new SignedPreKeyRecord(22, System.currentTimeMillis(), bobSignedPreKeyPair, bobSignedPreKeySignature));
+
+    SessionCipher bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+    byte[]        plaintext        = bobSessionCipher.decrypt(incomingMessage);
+
+    assertTrue(bobStore.containsSession(ALICE_RECIPIENT_ID, 1));
+    assertTrue(bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 3);
+    assertTrue(bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getAliceBaseKey() != null);
+    assertTrue(originalMessage.equals(new String(plaintext)));
+  }
+
+
+  private void runInteraction(AxolotlStore aliceStore, AxolotlStore bobStore)
+      throws DuplicateMessageException, LegacyMessageException, InvalidMessageException, NoSessionException
+  {
+    SessionCipher aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPIENT_ID, 1);
+    SessionCipher bobSessionCipher   = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    String originalMessage = "smert ze smert";
+    CiphertextMessage aliceMessage = aliceSessionCipher.encrypt(originalMessage.getBytes());
+
+    assertTrue(aliceMessage.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] plaintext = bobSessionCipher.decrypt(new WhisperMessage(aliceMessage.serialize()));
+    assertTrue(new String(plaintext).equals(originalMessage));
+
+    CiphertextMessage bobMessage = bobSessionCipher.encrypt(originalMessage.getBytes());
+
+    assertTrue(bobMessage.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    plaintext = aliceSessionCipher.decrypt(new WhisperMessage(bobMessage.serialize()));
+    assertTrue(new String(plaintext).equals(originalMessage));
+
+    for (int i=0;i<10;i++) {
+      String loopingMessage = ("What do we mean by saying that existence precedes essence? " +
+                               "We mean that man first of all exists, encounters himself, " +
+                               "surges up in the world--and defines himself aftward. " + i);
+      CiphertextMessage aliceLoopingMessage = aliceSessionCipher.encrypt(loopingMessage.getBytes());
+
+      byte[] loopingPlaintext = bobSessionCipher.decrypt(new WhisperMessage(aliceLoopingMessage.serialize()));
+      assertTrue(new String(loopingPlaintext).equals(loopingMessage));
+    }
+
+    for (int i=0;i<10;i++) {
+      String loopingMessage = ("What do we mean by saying that existence precedes essence? " +
+                               "We mean that man first of all exists, encounters himself, " +
+                               "surges up in the world--and defines himself aftward. " + i);
+      CiphertextMessage bobLoopingMessage = bobSessionCipher.encrypt(loopingMessage.getBytes());
+
+      byte[] loopingPlaintext = aliceSessionCipher.decrypt(new WhisperMessage(bobLoopingMessage.serialize()));
+      assertTrue(new String(loopingPlaintext).equals(loopingMessage));
+    }
+
+    Set<Pair<String, CiphertextMessage>> aliceOutOfOrderMessages = new HashSet<>();
+
+    for (int i=0;i<10;i++) {
+      String loopingMessage = ("What do we mean by saying that existence precedes essence? " +
+                               "We mean that man first of all exists, encounters himself, " +
+                               "surges up in the world--and defines himself aftward. " + i);
+      CiphertextMessage aliceLoopingMessage = aliceSessionCipher.encrypt(loopingMessage.getBytes());
+
+      aliceOutOfOrderMessages.add(new Pair<>(loopingMessage, aliceLoopingMessage));
+    }
+
+    for (int i=0;i<10;i++) {
+      String loopingMessage = ("What do we mean by saying that existence precedes essence? " +
+                               "We mean that man first of all exists, encounters himself, " +
+                               "surges up in the world--and defines himself aftward. " + i);
+      CiphertextMessage aliceLoopingMessage = aliceSessionCipher.encrypt(loopingMessage.getBytes());
+
+      byte[] loopingPlaintext = bobSessionCipher.decrypt(new WhisperMessage(aliceLoopingMessage.serialize()));
+      assertTrue(new String(loopingPlaintext).equals(loopingMessage));
+    }
+
+    for (int i=0;i<10;i++) {
+      String loopingMessage = ("You can only desire based on what you know: " + i);
+      CiphertextMessage bobLoopingMessage = bobSessionCipher.encrypt(loopingMessage.getBytes());
+
+      byte[] loopingPlaintext = aliceSessionCipher.decrypt(new WhisperMessage(bobLoopingMessage.serialize()));
+      assertTrue(new String(loopingPlaintext).equals(loopingMessage));
+    }
+
+    for (Pair<String, CiphertextMessage> aliceOutOfOrderMessage : aliceOutOfOrderMessages) {
+      byte[] outOfOrderPlaintext = bobSessionCipher.decrypt(new WhisperMessage(aliceOutOfOrderMessage.second().serialize()));
+      assertTrue(new String(outOfOrderPlaintext).equals(aliceOutOfOrderMessage.first()));
+    }
+  }
+
+
+}
diff --git a/src/androidTest/java/org/whispersystems/test/SessionCipherTest.java b/src/androidTest/java/org/whispersystems/test/SessionCipherTest.java
new file mode 100644
index 00000000..52b5fa89
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/SessionCipherTest.java
@@ -0,0 +1,206 @@
+package org.whispersystems.test;
+
+import android.test.AndroidTestCase;
+
+import org.whispersystems.libaxolotl.DuplicateMessageException;
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.IdentityKeyPair;
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.InvalidMessageException;
+import org.whispersystems.libaxolotl.LegacyMessageException;
+import org.whispersystems.libaxolotl.NoSessionException;
+import org.whispersystems.libaxolotl.SessionCipher;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.protocol.CiphertextMessage;
+import org.whispersystems.libaxolotl.protocol.WhisperMessage;
+import org.whispersystems.libaxolotl.ratchet.AliceAxolotlParameters;
+import org.whispersystems.libaxolotl.ratchet.BobAxolotlParameters;
+import org.whispersystems.libaxolotl.ratchet.RatchetingSession;
+import org.whispersystems.libaxolotl.state.AxolotlStore;
+import org.whispersystems.libaxolotl.state.SessionRecord;
+import org.whispersystems.libaxolotl.state.SessionState;
+import org.whispersystems.libaxolotl.util.guava.Optional;
+
+import java.security.NoSuchAlgorithmException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Random;
+
+
+public class SessionCipherTest extends AndroidTestCase {
+
+  public void testBasicSessionV2()
+      throws InvalidKeyException, DuplicateMessageException,
+      LegacyMessageException, InvalidMessageException, NoSuchAlgorithmException, NoSessionException
+  {
+    SessionRecord aliceSessionRecord = new SessionRecord();
+    SessionRecord bobSessionRecord   = new SessionRecord();
+
+    initializeSessionsV2(aliceSessionRecord.getSessionState(), bobSessionRecord.getSessionState());
+    runInteraction(aliceSessionRecord, bobSessionRecord);
+  }
+
+  public void testBasicSessionV3()
+      throws InvalidKeyException, DuplicateMessageException,
+      LegacyMessageException, InvalidMessageException, NoSuchAlgorithmException, NoSessionException
+  {
+    SessionRecord aliceSessionRecord = new SessionRecord();
+    SessionRecord bobSessionRecord   = new SessionRecord();
+
+    initializeSessionsV3(aliceSessionRecord.getSessionState(), bobSessionRecord.getSessionState());
+    runInteraction(aliceSessionRecord, bobSessionRecord);
+  }
+
+  private void runInteraction(SessionRecord aliceSessionRecord, SessionRecord bobSessionRecord)
+      throws DuplicateMessageException, LegacyMessageException, InvalidMessageException, NoSuchAlgorithmException, NoSessionException {
+    AxolotlStore aliceStore = new InMemoryAxolotlStore();
+    AxolotlStore bobStore   = new InMemoryAxolotlStore();
+
+    aliceStore.storeSession(2L, 1, aliceSessionRecord);
+    bobStore.storeSession(3L, 1, bobSessionRecord);
+
+    SessionCipher     aliceCipher    = new SessionCipher(aliceStore, 2L, 1);
+    SessionCipher     bobCipher      = new SessionCipher(bobStore, 3L, 1);
+
+    byte[]            alicePlaintext = "This is a plaintext message.".getBytes();
+    CiphertextMessage message        = aliceCipher.encrypt(alicePlaintext);
+    byte[]            bobPlaintext   = bobCipher.decrypt(new WhisperMessage(message.serialize()));
+
+    assertTrue(Arrays.equals(alicePlaintext, bobPlaintext));
+
+    byte[]            bobReply      = "This is a message from Bob.".getBytes();
+    CiphertextMessage reply         = bobCipher.encrypt(bobReply);
+    byte[]            receivedReply = aliceCipher.decrypt(new WhisperMessage(reply.serialize()));
+
+    assertTrue(Arrays.equals(bobReply, receivedReply));
+
+    List<CiphertextMessage> aliceCiphertextMessages = new ArrayList<>();
+    List<byte[]>            alicePlaintextMessages  = new ArrayList<>();
+
+    for (int i=0;i<50;i++) {
+      alicePlaintextMessages.add(("смерть за смерть " + i).getBytes());
+      aliceCiphertextMessages.add(aliceCipher.encrypt(("смерть за смерть " + i).getBytes()));
+    }
+
+    long seed = System.currentTimeMillis();
+
+    Collections.shuffle(aliceCiphertextMessages, new Random(seed));
+    Collections.shuffle(alicePlaintextMessages, new Random(seed));
+
+    for (int i=0;i<aliceCiphertextMessages.size() / 2;i++) {
+      byte[] receivedPlaintext = bobCipher.decrypt(new WhisperMessage(aliceCiphertextMessages.get(i).serialize()));
+      assertTrue(Arrays.equals(receivedPlaintext, alicePlaintextMessages.get(i)));
+    }
+
+    List<CiphertextMessage> bobCiphertextMessages = new ArrayList<>();
+    List<byte[]>            bobPlaintextMessages  = new ArrayList<>();
+
+    for (int i=0;i<20;i++) {
+      bobPlaintextMessages.add(("смерть за смерть " + i).getBytes());
+      bobCiphertextMessages.add(bobCipher.encrypt(("смерть за смерть " + i).getBytes()));
+    }
+
+    seed = System.currentTimeMillis();
+
+    Collections.shuffle(bobCiphertextMessages, new Random(seed));
+    Collections.shuffle(bobPlaintextMessages, new Random(seed));
+
+    for (int i=0;i<bobCiphertextMessages.size() / 2;i++) {
+      byte[] receivedPlaintext = aliceCipher.decrypt(new WhisperMessage(bobCiphertextMessages.get(i).serialize()));
+      assertTrue(Arrays.equals(receivedPlaintext, bobPlaintextMessages.get(i)));
+    }
+
+    for (int i=aliceCiphertextMessages.size()/2;i<aliceCiphertextMessages.size();i++) {
+      byte[] receivedPlaintext = bobCipher.decrypt(new WhisperMessage(aliceCiphertextMessages.get(i).serialize()));
+      assertTrue(Arrays.equals(receivedPlaintext, alicePlaintextMessages.get(i)));
+    }
+
+    for (int i=bobCiphertextMessages.size() / 2;i<bobCiphertextMessages.size();i++) {
+      byte[] receivedPlaintext = aliceCipher.decrypt(new WhisperMessage(bobCiphertextMessages.get(i).serialize()));
+      assertTrue(Arrays.equals(receivedPlaintext, bobPlaintextMessages.get(i)));
+    }
+  }
+
+
+  private void initializeSessionsV2(SessionState aliceSessionState, SessionState bobSessionState)
+      throws InvalidKeyException
+  {
+    ECKeyPair       aliceIdentityKeyPair = Curve.generateKeyPair();
+    IdentityKeyPair aliceIdentityKey     = new IdentityKeyPair(new IdentityKey(aliceIdentityKeyPair.getPublicKey()),
+                                                               aliceIdentityKeyPair.getPrivateKey());
+    ECKeyPair       aliceBaseKey         = Curve.generateKeyPair();
+    ECKeyPair       aliceEphemeralKey    = Curve.generateKeyPair();
+
+    ECKeyPair       bobIdentityKeyPair   = Curve.generateKeyPair();
+    IdentityKeyPair bobIdentityKey       = new IdentityKeyPair(new IdentityKey(bobIdentityKeyPair.getPublicKey()),
+                                                               bobIdentityKeyPair.getPrivateKey());
+    ECKeyPair       bobBaseKey           = Curve.generateKeyPair();
+    ECKeyPair       bobEphemeralKey      = bobBaseKey;
+
+    AliceAxolotlParameters aliceParameters = AliceAxolotlParameters.newBuilder()
+        .setOurIdentityKey(aliceIdentityKey)
+        .setOurBaseKey(aliceBaseKey)
+        .setTheirIdentityKey(bobIdentityKey.getPublicKey())
+        .setTheirSignedPreKey(bobEphemeralKey.getPublicKey())
+        .setTheirRatchetKey(bobEphemeralKey.getPublicKey())
+        .setTheirOneTimePreKey(Optional.<ECPublicKey>absent())
+        .create();
+
+    BobAxolotlParameters bobParameters = BobAxolotlParameters.newBuilder()
+        .setOurIdentityKey(bobIdentityKey)
+        .setOurOneTimePreKey(Optional.<ECKeyPair>absent())
+        .setOurRatchetKey(bobEphemeralKey)
+        .setOurSignedPreKey(bobBaseKey)
+        .setTheirBaseKey(aliceBaseKey.getPublicKey())
+        .setTheirIdentityKey(aliceIdentityKey.getPublicKey())
+        .create();
+
+    RatchetingSession.initializeSession(aliceSessionState, 2, aliceParameters);
+    RatchetingSession.initializeSession(bobSessionState, 2, bobParameters);
+  }
+
+  private void initializeSessionsV3(SessionState aliceSessionState, SessionState bobSessionState)
+      throws InvalidKeyException
+  {
+    ECKeyPair       aliceIdentityKeyPair = Curve.generateKeyPair();
+    IdentityKeyPair aliceIdentityKey     = new IdentityKeyPair(new IdentityKey(aliceIdentityKeyPair.getPublicKey()),
+                                                               aliceIdentityKeyPair.getPrivateKey());
+    ECKeyPair       aliceBaseKey         = Curve.generateKeyPair();
+    ECKeyPair       aliceEphemeralKey    = Curve.generateKeyPair();
+
+    ECKeyPair       alicePreKey          = aliceBaseKey;
+
+    ECKeyPair       bobIdentityKeyPair   = Curve.generateKeyPair();
+    IdentityKeyPair bobIdentityKey       = new IdentityKeyPair(new IdentityKey(bobIdentityKeyPair.getPublicKey()),
+                                                               bobIdentityKeyPair.getPrivateKey());
+    ECKeyPair       bobBaseKey           = Curve.generateKeyPair();
+    ECKeyPair       bobEphemeralKey      = bobBaseKey;
+
+    ECKeyPair       bobPreKey            = Curve.generateKeyPair();
+
+    AliceAxolotlParameters aliceParameters = AliceAxolotlParameters.newBuilder()
+        .setOurBaseKey(aliceBaseKey)
+        .setOurIdentityKey(aliceIdentityKey)
+        .setTheirOneTimePreKey(Optional.<ECPublicKey>absent())
+        .setTheirRatchetKey(bobEphemeralKey.getPublicKey())
+        .setTheirSignedPreKey(bobBaseKey.getPublicKey())
+        .setTheirIdentityKey(bobIdentityKey.getPublicKey())
+        .create();
+
+    BobAxolotlParameters bobParameters = BobAxolotlParameters.newBuilder()
+        .setOurRatchetKey(bobEphemeralKey)
+        .setOurSignedPreKey(bobBaseKey)
+        .setOurOneTimePreKey(Optional.<ECKeyPair>absent())
+        .setOurIdentityKey(bobIdentityKey)
+        .setTheirIdentityKey(aliceIdentityKey.getPublicKey())
+        .setTheirBaseKey(aliceBaseKey.getPublicKey())
+        .create();
+
+    RatchetingSession.initializeSession(aliceSessionState, 3, aliceParameters);
+    RatchetingSession.initializeSession(bobSessionState, 3, bobParameters);
+  }
+}
diff --git a/src/androidTest/java/org/whispersystems/test/SimultaneousInitiateTests.java b/src/androidTest/java/org/whispersystems/test/SimultaneousInitiateTests.java
new file mode 100644
index 00000000..dffde57c
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/SimultaneousInitiateTests.java
@@ -0,0 +1,501 @@
+package org.whispersystems.test;
+
+import android.test.AndroidTestCase;
+import android.util.Log;
+
+import org.whispersystems.libaxolotl.DuplicateMessageException;
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.InvalidKeyIdException;
+import org.whispersystems.libaxolotl.InvalidMessageException;
+import org.whispersystems.libaxolotl.InvalidVersionException;
+import org.whispersystems.libaxolotl.LegacyMessageException;
+import org.whispersystems.libaxolotl.NoSessionException;
+import org.whispersystems.libaxolotl.SessionBuilder;
+import org.whispersystems.libaxolotl.SessionCipher;
+import org.whispersystems.libaxolotl.UntrustedIdentityException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.protocol.CiphertextMessage;
+import org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage;
+import org.whispersystems.libaxolotl.protocol.WhisperMessage;
+import org.whispersystems.libaxolotl.state.AxolotlStore;
+import org.whispersystems.libaxolotl.state.PreKeyBundle;
+import org.whispersystems.libaxolotl.state.PreKeyRecord;
+import org.whispersystems.libaxolotl.state.SignedPreKeyRecord;
+import org.whispersystems.libaxolotl.util.Medium;
+
+import java.util.Arrays;
+import java.util.Random;
+
+public class SimultaneousInitiateTests extends AndroidTestCase {
+
+  private static final long BOB_RECIPENT_ID    = 12345;
+  private static final long ALICE_RECIPIENT_ID = 6789;
+
+  private static final ECKeyPair aliceSignedPreKey = Curve.generateKeyPair();
+  private static final ECKeyPair bobSignedPreKey   = Curve.generateKeyPair();
+
+  private static final int aliceSignedPreKeyId = new Random().nextInt(Medium.MAX_VALUE);
+  private static final int bobSignedPreKeyId   = new Random().nextInt(Medium.MAX_VALUE);
+
+  public void testBasicSimultaneousInitiate()
+      throws InvalidKeyException, UntrustedIdentityException, InvalidVersionException,
+      InvalidMessageException, DuplicateMessageException, LegacyMessageException,
+      InvalidKeyIdException, NoSessionException
+  {
+    AxolotlStore aliceStore = new InMemoryAxolotlStore();
+    AxolotlStore bobStore   = new InMemoryAxolotlStore();
+
+    PreKeyBundle alicePreKeyBundle = createAlicePreKeyBundle(aliceStore);
+    PreKeyBundle bobPreKeyBundle = createBobPreKeyBundle(bobStore);
+
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionBuilder bobSessionBuilder   = new SessionBuilder(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    SessionCipher aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionCipher bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    aliceSessionBuilder.process(bobPreKeyBundle);
+    bobSessionBuilder.process(alicePreKeyBundle);
+
+    CiphertextMessage messageForBob   = aliceSessionCipher.encrypt("hey there".getBytes());
+    CiphertextMessage messageForAlice = bobSessionCipher.encrypt("sample message".getBytes());
+
+    assertTrue(messageForBob.getType() == CiphertextMessage.PREKEY_TYPE);
+    assertTrue(messageForAlice.getType() == CiphertextMessage.PREKEY_TYPE);
+
+    assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+    byte[] alicePlaintext = aliceSessionCipher.decrypt(new PreKeyWhisperMessage(messageForAlice.serialize()));
+    byte[] bobPlaintext   = bobSessionCipher.decrypt(new PreKeyWhisperMessage(messageForBob.serialize()));
+
+    assertTrue(new String(alicePlaintext).equals("sample message"));
+    assertTrue(new String(bobPlaintext).equals("hey there"));
+
+    assertTrue(aliceStore.loadSession(BOB_RECIPENT_ID, 1).getSessionState().getSessionVersion() == 3);
+    assertTrue(bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 3);
+
+    assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+    CiphertextMessage aliceResponse = aliceSessionCipher.encrypt("second message".getBytes());
+
+    assertTrue(aliceResponse.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] responsePlaintext = bobSessionCipher.decrypt(new WhisperMessage(aliceResponse.serialize()));
+
+    assertTrue(new String(responsePlaintext).equals("second message"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+
+    CiphertextMessage finalMessage = bobSessionCipher.encrypt("third message".getBytes());
+
+    assertTrue(finalMessage.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] finalPlaintext = aliceSessionCipher.decrypt(new WhisperMessage(finalMessage.serialize()));
+
+    assertTrue(new String(finalPlaintext).equals("third message"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+  }
+
+  public void testLostSimultaneousInitiate() throws InvalidKeyException, UntrustedIdentityException, InvalidVersionException, InvalidMessageException, DuplicateMessageException, LegacyMessageException, InvalidKeyIdException, NoSessionException {
+    AxolotlStore aliceStore = new InMemoryAxolotlStore();
+    AxolotlStore bobStore   = new InMemoryAxolotlStore();
+
+    PreKeyBundle alicePreKeyBundle = createAlicePreKeyBundle(aliceStore);
+    PreKeyBundle bobPreKeyBundle = createBobPreKeyBundle(bobStore);
+
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionBuilder bobSessionBuilder   = new SessionBuilder(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    SessionCipher aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionCipher bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    aliceSessionBuilder.process(bobPreKeyBundle);
+    bobSessionBuilder.process(alicePreKeyBundle);
+
+    CiphertextMessage messageForBob   = aliceSessionCipher.encrypt("hey there".getBytes());
+    CiphertextMessage messageForAlice = bobSessionCipher.encrypt("sample message".getBytes());
+
+    assertTrue(messageForBob.getType() == CiphertextMessage.PREKEY_TYPE);
+    assertTrue(messageForAlice.getType() == CiphertextMessage.PREKEY_TYPE);
+
+    assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+    byte[] bobPlaintext   = bobSessionCipher.decrypt(new PreKeyWhisperMessage(messageForBob.serialize()));
+
+    assertTrue(new String(bobPlaintext).equals("hey there"));
+    assertTrue(bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 3);
+
+    CiphertextMessage aliceResponse = aliceSessionCipher.encrypt("second message".getBytes());
+
+    assertTrue(aliceResponse.getType() == CiphertextMessage.PREKEY_TYPE);
+
+    byte[] responsePlaintext = bobSessionCipher.decrypt(new PreKeyWhisperMessage(aliceResponse.serialize()));
+
+    assertTrue(new String(responsePlaintext).equals("second message"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+
+    CiphertextMessage finalMessage = bobSessionCipher.encrypt("third message".getBytes());
+
+    assertTrue(finalMessage.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] finalPlaintext = aliceSessionCipher.decrypt(new WhisperMessage(finalMessage.serialize()));
+
+    assertTrue(new String(finalPlaintext).equals("third message"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+  }
+
+  public void testSimultaneousInitiateLostMessage()
+      throws InvalidKeyException, UntrustedIdentityException, InvalidVersionException,
+      InvalidMessageException, DuplicateMessageException, LegacyMessageException,
+      InvalidKeyIdException, NoSessionException
+  {
+    AxolotlStore aliceStore = new InMemoryAxolotlStore();
+    AxolotlStore bobStore   = new InMemoryAxolotlStore();
+
+    PreKeyBundle alicePreKeyBundle = createAlicePreKeyBundle(aliceStore);
+    PreKeyBundle bobPreKeyBundle = createBobPreKeyBundle(bobStore);
+
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionBuilder bobSessionBuilder   = new SessionBuilder(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    SessionCipher aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionCipher bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    aliceSessionBuilder.process(bobPreKeyBundle);
+    bobSessionBuilder.process(alicePreKeyBundle);
+
+    CiphertextMessage messageForBob   = aliceSessionCipher.encrypt("hey there".getBytes());
+    CiphertextMessage messageForAlice = bobSessionCipher.encrypt("sample message".getBytes());
+
+    assertTrue(messageForBob.getType() == CiphertextMessage.PREKEY_TYPE);
+    assertTrue(messageForAlice.getType() == CiphertextMessage.PREKEY_TYPE);
+
+    assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+    byte[] alicePlaintext = aliceSessionCipher.decrypt(new PreKeyWhisperMessage(messageForAlice.serialize()));
+    byte[] bobPlaintext   = bobSessionCipher.decrypt(new PreKeyWhisperMessage(messageForBob.serialize()));
+
+    assertTrue(new String(alicePlaintext).equals("sample message"));
+    assertTrue(new String(bobPlaintext).equals("hey there"));
+
+    assertTrue(aliceStore.loadSession(BOB_RECIPENT_ID, 1).getSessionState().getSessionVersion() == 3);
+    assertTrue(bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 3);
+
+    assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+    CiphertextMessage aliceResponse = aliceSessionCipher.encrypt("second message".getBytes());
+
+    assertTrue(aliceResponse.getType() == CiphertextMessage.WHISPER_TYPE);
+
+//    byte[] responsePlaintext = bobSessionCipher.decrypt(new WhisperMessage(aliceResponse.serialize()));
+//
+//    assertTrue(new String(responsePlaintext).equals("second message"));
+//    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+    assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+    CiphertextMessage finalMessage = bobSessionCipher.encrypt("third message".getBytes());
+
+    assertTrue(finalMessage.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] finalPlaintext = aliceSessionCipher.decrypt(new WhisperMessage(finalMessage.serialize()));
+
+    assertTrue(new String(finalPlaintext).equals("third message"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+  }
+
+  public void testSimultaneousInitiateRepeatedMessages()
+      throws InvalidKeyException, UntrustedIdentityException, InvalidVersionException,
+      InvalidMessageException, DuplicateMessageException, LegacyMessageException,
+      InvalidKeyIdException, NoSessionException
+  {
+    AxolotlStore aliceStore = new InMemoryAxolotlStore();
+    AxolotlStore bobStore   = new InMemoryAxolotlStore();
+
+    PreKeyBundle alicePreKeyBundle = createAlicePreKeyBundle(aliceStore);
+    PreKeyBundle bobPreKeyBundle = createBobPreKeyBundle(bobStore);
+
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionBuilder bobSessionBuilder   = new SessionBuilder(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    SessionCipher aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionCipher bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    aliceSessionBuilder.process(bobPreKeyBundle);
+    bobSessionBuilder.process(alicePreKeyBundle);
+
+    CiphertextMessage messageForBob   = aliceSessionCipher.encrypt("hey there".getBytes());
+    CiphertextMessage messageForAlice = bobSessionCipher.encrypt("sample message".getBytes());
+
+    assertTrue(messageForBob.getType() == CiphertextMessage.PREKEY_TYPE);
+    assertTrue(messageForAlice.getType() == CiphertextMessage.PREKEY_TYPE);
+
+    assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+    byte[] alicePlaintext = aliceSessionCipher.decrypt(new PreKeyWhisperMessage(messageForAlice.serialize()));
+    byte[] bobPlaintext   = bobSessionCipher.decrypt(new PreKeyWhisperMessage(messageForBob.serialize()));
+
+    assertTrue(new String(alicePlaintext).equals("sample message"));
+    assertTrue(new String(bobPlaintext).equals("hey there"));
+
+    assertTrue(aliceStore.loadSession(BOB_RECIPENT_ID, 1).getSessionState().getSessionVersion() == 3);
+    assertTrue(bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 3);
+
+    assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+    for (int i=0;i<50;i++) {
+      Log.w("SimultaneousInitiateTests", "Iteration: " + i);
+      CiphertextMessage messageForBobRepeat   = aliceSessionCipher.encrypt("hey there".getBytes());
+      CiphertextMessage messageForAliceRepeat = bobSessionCipher.encrypt("sample message".getBytes());
+
+      assertTrue(messageForBobRepeat.getType() == CiphertextMessage.WHISPER_TYPE);
+      assertTrue(messageForAliceRepeat.getType() == CiphertextMessage.WHISPER_TYPE);
+
+      assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+      byte[] alicePlaintextRepeat = aliceSessionCipher.decrypt(new WhisperMessage(messageForAliceRepeat.serialize()));
+      byte[] bobPlaintextRepeat   = bobSessionCipher.decrypt(new WhisperMessage(messageForBobRepeat.serialize()));
+
+      assertTrue(new String(alicePlaintextRepeat).equals("sample message"));
+      assertTrue(new String(bobPlaintextRepeat).equals("hey there"));
+
+      assertFalse(isSessionIdEqual(aliceStore, bobStore));
+    }
+
+    CiphertextMessage aliceResponse = aliceSessionCipher.encrypt("second message".getBytes());
+
+    assertTrue(aliceResponse.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] responsePlaintext = bobSessionCipher.decrypt(new WhisperMessage(aliceResponse.serialize()));
+
+    assertTrue(new String(responsePlaintext).equals("second message"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+
+    CiphertextMessage finalMessage = bobSessionCipher.encrypt("third message".getBytes());
+
+    assertTrue(finalMessage.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] finalPlaintext = aliceSessionCipher.decrypt(new WhisperMessage(finalMessage.serialize()));
+
+    assertTrue(new String(finalPlaintext).equals("third message"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+  }
+
+  public void testRepeatedSimultaneousInitiateRepeatedMessages()
+      throws InvalidKeyException, UntrustedIdentityException, InvalidVersionException,
+      InvalidMessageException, DuplicateMessageException, LegacyMessageException,
+      InvalidKeyIdException, NoSessionException
+  {
+    AxolotlStore aliceStore = new InMemoryAxolotlStore();
+    AxolotlStore bobStore   = new InMemoryAxolotlStore();
+
+
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionBuilder bobSessionBuilder   = new SessionBuilder(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    SessionCipher aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionCipher bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    for (int i=0;i<15;i++) {
+      PreKeyBundle alicePreKeyBundle = createAlicePreKeyBundle(aliceStore);
+      PreKeyBundle bobPreKeyBundle   = createBobPreKeyBundle(bobStore);
+
+      aliceSessionBuilder.process(bobPreKeyBundle);
+      bobSessionBuilder.process(alicePreKeyBundle);
+
+      CiphertextMessage messageForBob = aliceSessionCipher.encrypt("hey there".getBytes());
+      CiphertextMessage messageForAlice = bobSessionCipher.encrypt("sample message".getBytes());
+
+      assertTrue(messageForBob.getType() == CiphertextMessage.PREKEY_TYPE);
+      assertTrue(messageForAlice.getType() == CiphertextMessage.PREKEY_TYPE);
+
+      assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+      byte[] alicePlaintext = aliceSessionCipher.decrypt(new PreKeyWhisperMessage(messageForAlice.serialize()));
+      byte[] bobPlaintext = bobSessionCipher.decrypt(new PreKeyWhisperMessage(messageForBob.serialize()));
+
+      assertTrue(new String(alicePlaintext).equals("sample message"));
+      assertTrue(new String(bobPlaintext).equals("hey there"));
+
+      assertTrue(aliceStore.loadSession(BOB_RECIPENT_ID, 1).getSessionState().getSessionVersion() == 3);
+      assertTrue(bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 3);
+
+      assertFalse(isSessionIdEqual(aliceStore, bobStore));
+    }
+
+    for (int i=0;i<50;i++) {
+      Log.w("SimultaneousInitiateTests", "Iteration: " + i);
+      CiphertextMessage messageForBobRepeat   = aliceSessionCipher.encrypt("hey there".getBytes());
+      CiphertextMessage messageForAliceRepeat = bobSessionCipher.encrypt("sample message".getBytes());
+
+      assertTrue(messageForBobRepeat.getType() == CiphertextMessage.WHISPER_TYPE);
+      assertTrue(messageForAliceRepeat.getType() == CiphertextMessage.WHISPER_TYPE);
+
+      assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+      byte[] alicePlaintextRepeat = aliceSessionCipher.decrypt(new WhisperMessage(messageForAliceRepeat.serialize()));
+      byte[] bobPlaintextRepeat   = bobSessionCipher.decrypt(new WhisperMessage(messageForBobRepeat.serialize()));
+
+      assertTrue(new String(alicePlaintextRepeat).equals("sample message"));
+      assertTrue(new String(bobPlaintextRepeat).equals("hey there"));
+
+      assertFalse(isSessionIdEqual(aliceStore, bobStore));
+    }
+
+    CiphertextMessage aliceResponse = aliceSessionCipher.encrypt("second message".getBytes());
+
+    assertTrue(aliceResponse.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] responsePlaintext = bobSessionCipher.decrypt(new WhisperMessage(aliceResponse.serialize()));
+
+    assertTrue(new String(responsePlaintext).equals("second message"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+
+    CiphertextMessage finalMessage = bobSessionCipher.encrypt("third message".getBytes());
+
+    assertTrue(finalMessage.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] finalPlaintext = aliceSessionCipher.decrypt(new WhisperMessage(finalMessage.serialize()));
+
+    assertTrue(new String(finalPlaintext).equals("third message"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+  }
+
+  public void testRepeatedSimultaneousInitiateLostMessageRepeatedMessages()
+      throws InvalidKeyException, UntrustedIdentityException, InvalidVersionException,
+      InvalidMessageException, DuplicateMessageException, LegacyMessageException,
+      InvalidKeyIdException, NoSessionException
+  {
+    AxolotlStore aliceStore = new InMemoryAxolotlStore();
+    AxolotlStore bobStore   = new InMemoryAxolotlStore();
+
+
+    SessionBuilder aliceSessionBuilder = new SessionBuilder(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionBuilder bobSessionBuilder   = new SessionBuilder(bobStore, ALICE_RECIPIENT_ID, 1);
+
+    SessionCipher aliceSessionCipher = new SessionCipher(aliceStore, BOB_RECIPENT_ID, 1);
+    SessionCipher bobSessionCipher = new SessionCipher(bobStore, ALICE_RECIPIENT_ID, 1);
+
+//    PreKeyBundle aliceLostPreKeyBundle = createAlicePreKeyBundle(aliceStore);
+    PreKeyBundle bobLostPreKeyBundle   = createBobPreKeyBundle(bobStore);
+
+    aliceSessionBuilder.process(bobLostPreKeyBundle);
+//    bobSessionBuilder.process(aliceLostPreKeyBundle);
+
+    CiphertextMessage lostMessageForBob   = aliceSessionCipher.encrypt("hey there".getBytes());
+//    CiphertextMessage lostMessageForAlice = bobSessionCipher.encrypt("sample message".getBytes());
+
+    for (int i=0;i<15;i++) {
+      PreKeyBundle alicePreKeyBundle = createAlicePreKeyBundle(aliceStore);
+      PreKeyBundle bobPreKeyBundle   = createBobPreKeyBundle(bobStore);
+
+      aliceSessionBuilder.process(bobPreKeyBundle);
+      bobSessionBuilder.process(alicePreKeyBundle);
+
+      CiphertextMessage messageForBob = aliceSessionCipher.encrypt("hey there".getBytes());
+      CiphertextMessage messageForAlice = bobSessionCipher.encrypt("sample message".getBytes());
+
+      assertTrue(messageForBob.getType() == CiphertextMessage.PREKEY_TYPE);
+      assertTrue(messageForAlice.getType() == CiphertextMessage.PREKEY_TYPE);
+
+      assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+      byte[] alicePlaintext = aliceSessionCipher.decrypt(new PreKeyWhisperMessage(messageForAlice.serialize()));
+      byte[] bobPlaintext = bobSessionCipher.decrypt(new PreKeyWhisperMessage(messageForBob.serialize()));
+
+      assertTrue(new String(alicePlaintext).equals("sample message"));
+      assertTrue(new String(bobPlaintext).equals("hey there"));
+
+      assertTrue(aliceStore.loadSession(BOB_RECIPENT_ID, 1).getSessionState().getSessionVersion() == 3);
+      assertTrue(bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getSessionVersion() == 3);
+
+      assertFalse(isSessionIdEqual(aliceStore, bobStore));
+    }
+
+    for (int i=0;i<50;i++) {
+      Log.w("SimultaneousInitiateTests", "Iteration: " + i);
+      CiphertextMessage messageForBobRepeat   = aliceSessionCipher.encrypt("hey there".getBytes());
+      CiphertextMessage messageForAliceRepeat = bobSessionCipher.encrypt("sample message".getBytes());
+
+      assertTrue(messageForBobRepeat.getType() == CiphertextMessage.WHISPER_TYPE);
+      assertTrue(messageForAliceRepeat.getType() == CiphertextMessage.WHISPER_TYPE);
+
+      assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+      byte[] alicePlaintextRepeat = aliceSessionCipher.decrypt(new WhisperMessage(messageForAliceRepeat.serialize()));
+      byte[] bobPlaintextRepeat   = bobSessionCipher.decrypt(new WhisperMessage(messageForBobRepeat.serialize()));
+
+      assertTrue(new String(alicePlaintextRepeat).equals("sample message"));
+      assertTrue(new String(bobPlaintextRepeat).equals("hey there"));
+
+      assertFalse(isSessionIdEqual(aliceStore, bobStore));
+    }
+
+    CiphertextMessage aliceResponse = aliceSessionCipher.encrypt("second message".getBytes());
+
+    assertTrue(aliceResponse.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] responsePlaintext = bobSessionCipher.decrypt(new WhisperMessage(aliceResponse.serialize()));
+
+    assertTrue(new String(responsePlaintext).equals("second message"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+
+    CiphertextMessage finalMessage = bobSessionCipher.encrypt("third message".getBytes());
+
+    assertTrue(finalMessage.getType() == CiphertextMessage.WHISPER_TYPE);
+
+    byte[] finalPlaintext = aliceSessionCipher.decrypt(new WhisperMessage(finalMessage.serialize()));
+
+    assertTrue(new String(finalPlaintext).equals("third message"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+
+    byte[] lostMessagePlaintext = bobSessionCipher.decrypt(new PreKeyWhisperMessage(lostMessageForBob.serialize()));
+    assertTrue(new String(lostMessagePlaintext).equals("hey there"));
+
+    assertFalse(isSessionIdEqual(aliceStore, bobStore));
+
+    CiphertextMessage blastFromThePast          = bobSessionCipher.encrypt("unexpected!".getBytes());
+    byte[]            blastFromThePastPlaintext = aliceSessionCipher.decrypt(new WhisperMessage(blastFromThePast.serialize()));
+
+    assertTrue(new String(blastFromThePastPlaintext).equals("unexpected!"));
+    assertTrue(isSessionIdEqual(aliceStore, bobStore));
+  }
+
+  private boolean isSessionIdEqual(AxolotlStore aliceStore, AxolotlStore bobStore) {
+    return Arrays.equals(aliceStore.loadSession(BOB_RECIPENT_ID, 1).getSessionState().getAliceBaseKey(),
+                         bobStore.loadSession(ALICE_RECIPIENT_ID, 1).getSessionState().getAliceBaseKey());
+  }
+
+  private PreKeyBundle createAlicePreKeyBundle(AxolotlStore aliceStore) throws InvalidKeyException {
+    ECKeyPair aliceUnsignedPreKey   = Curve.generateKeyPair();
+    int       aliceUnsignedPreKeyId = new Random().nextInt(Medium.MAX_VALUE);
+    byte[]    aliceSignature        = Curve.calculateSignature(aliceStore.getIdentityKeyPair().getPrivateKey(),
+                                                               aliceSignedPreKey.getPublicKey().serialize());
+
+    PreKeyBundle alicePreKeyBundle = new PreKeyBundle(1, 1,
+                                                      aliceUnsignedPreKeyId, aliceUnsignedPreKey.getPublicKey(),
+                                                      aliceSignedPreKeyId, aliceSignedPreKey.getPublicKey(),
+                                                      aliceSignature, aliceStore.getIdentityKeyPair().getPublicKey());
+
+    aliceStore.storeSignedPreKey(aliceSignedPreKeyId, new SignedPreKeyRecord(aliceSignedPreKeyId, System.currentTimeMillis(), aliceSignedPreKey, aliceSignature));
+    aliceStore.storePreKey(aliceUnsignedPreKeyId, new PreKeyRecord(aliceUnsignedPreKeyId, aliceUnsignedPreKey));
+
+    return alicePreKeyBundle;
+  }
+
+  private PreKeyBundle createBobPreKeyBundle(AxolotlStore bobStore) throws InvalidKeyException {
+    ECKeyPair bobUnsignedPreKey   = Curve.generateKeyPair();
+    int       bobUnsignedPreKeyId = new Random().nextInt(Medium.MAX_VALUE);
+    byte[]    bobSignature        = Curve.calculateSignature(bobStore.getIdentityKeyPair().getPrivateKey(),
+                                                             bobSignedPreKey.getPublicKey().serialize());
+
+    PreKeyBundle bobPreKeyBundle = new PreKeyBundle(1, 1,
+                                                    bobUnsignedPreKeyId, bobUnsignedPreKey.getPublicKey(),
+                                                    bobSignedPreKeyId, bobSignedPreKey.getPublicKey(),
+                                                    bobSignature, bobStore.getIdentityKeyPair().getPublicKey());
+
+    bobStore.storeSignedPreKey(bobSignedPreKeyId, new SignedPreKeyRecord(bobSignedPreKeyId, System.currentTimeMillis(), bobSignedPreKey, bobSignature));
+    bobStore.storePreKey(bobUnsignedPreKeyId, new PreKeyRecord(bobUnsignedPreKeyId, bobUnsignedPreKey));
+
+    return bobPreKeyBundle;
+  }
+}
diff --git a/src/androidTest/java/org/whispersystems/test/ecc/Curve25519Test.java b/src/androidTest/java/org/whispersystems/test/ecc/Curve25519Test.java
new file mode 100644
index 00000000..4b8ce2ea
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/ecc/Curve25519Test.java
@@ -0,0 +1,154 @@
+package org.whispersystems.test.ecc;
+
+import android.test.AndroidTestCase;
+
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPrivateKey;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+
+import java.util.Arrays;
+
+
+public class Curve25519Test extends AndroidTestCase {
+
+  public void testAgreement() throws InvalidKeyException {
+
+    byte[] alicePublic  = {(byte) 0x05, (byte) 0x1b, (byte) 0xb7, (byte) 0x59, (byte) 0x66,
+                           (byte) 0xf2, (byte) 0xe9, (byte) 0x3a, (byte) 0x36, (byte) 0x91,
+                           (byte) 0xdf, (byte) 0xff, (byte) 0x94, (byte) 0x2b, (byte) 0xb2,
+                           (byte) 0xa4, (byte) 0x66, (byte) 0xa1, (byte) 0xc0, (byte) 0x8b,
+                           (byte) 0x8d, (byte) 0x78, (byte) 0xca, (byte) 0x3f, (byte) 0x4d,
+                           (byte) 0x6d, (byte) 0xf8, (byte) 0xb8, (byte) 0xbf, (byte) 0xa2,
+                           (byte) 0xe4, (byte) 0xee, (byte) 0x28};
+
+    byte[] alicePrivate = {(byte) 0xc8, (byte) 0x06, (byte) 0x43, (byte) 0x9d, (byte) 0xc9,
+                           (byte) 0xd2, (byte) 0xc4, (byte) 0x76, (byte) 0xff, (byte) 0xed,
+                           (byte) 0x8f, (byte) 0x25, (byte) 0x80, (byte) 0xc0, (byte) 0x88,
+                           (byte) 0x8d, (byte) 0x58, (byte) 0xab, (byte) 0x40, (byte) 0x6b,
+                           (byte) 0xf7, (byte) 0xae, (byte) 0x36, (byte) 0x98, (byte) 0x87,
+                           (byte) 0x90, (byte) 0x21, (byte) 0xb9, (byte) 0x6b, (byte) 0xb4,
+                           (byte) 0xbf, (byte) 0x59};
+
+    byte[] bobPublic    = {(byte) 0x05, (byte) 0x65, (byte) 0x36, (byte) 0x14, (byte) 0x99,
+                           (byte) 0x3d, (byte) 0x2b, (byte) 0x15, (byte) 0xee, (byte) 0x9e,
+                           (byte) 0x5f, (byte) 0xd3, (byte) 0xd8, (byte) 0x6c, (byte) 0xe7,
+                           (byte) 0x19, (byte) 0xef, (byte) 0x4e, (byte) 0xc1, (byte) 0xda,
+                           (byte) 0xae, (byte) 0x18, (byte) 0x86, (byte) 0xa8, (byte) 0x7b,
+                           (byte) 0x3f, (byte) 0x5f, (byte) 0xa9, (byte) 0x56, (byte) 0x5a,
+                           (byte) 0x27, (byte) 0xa2, (byte) 0x2f};
+
+    byte[] bobPrivate   = {(byte) 0xb0, (byte) 0x3b, (byte) 0x34, (byte) 0xc3, (byte) 0x3a,
+                           (byte) 0x1c, (byte) 0x44, (byte) 0xf2, (byte) 0x25, (byte) 0xb6,
+                           (byte) 0x62, (byte) 0xd2, (byte) 0xbf, (byte) 0x48, (byte) 0x59,
+                           (byte) 0xb8, (byte) 0x13, (byte) 0x54, (byte) 0x11, (byte) 0xfa,
+                           (byte) 0x7b, (byte) 0x03, (byte) 0x86, (byte) 0xd4, (byte) 0x5f,
+                           (byte) 0xb7, (byte) 0x5d, (byte) 0xc5, (byte) 0xb9, (byte) 0x1b,
+                           (byte) 0x44, (byte) 0x66};
+
+    byte[] shared       = {(byte) 0x32, (byte) 0x5f, (byte) 0x23, (byte) 0x93, (byte) 0x28,
+                           (byte) 0x94, (byte) 0x1c, (byte) 0xed, (byte) 0x6e, (byte) 0x67,
+                           (byte) 0x3b, (byte) 0x86, (byte) 0xba, (byte) 0x41, (byte) 0x01,
+                           (byte) 0x74, (byte) 0x48, (byte) 0xe9, (byte) 0x9b, (byte) 0x64,
+                           (byte) 0x9a, (byte) 0x9c, (byte) 0x38, (byte) 0x06, (byte) 0xc1,
+                           (byte) 0xdd, (byte) 0x7c, (byte) 0xa4, (byte) 0xc4, (byte) 0x77,
+                           (byte) 0xe6, (byte) 0x29};
+
+    ECPublicKey alicePublicKey = Curve.decodePoint(alicePublic, 0);
+    ECPrivateKey alicePrivateKey = Curve.decodePrivatePoint(alicePrivate);
+
+    ECPublicKey bobPublicKey = Curve.decodePoint(bobPublic, 0);
+    ECPrivateKey bobPrivateKey = Curve.decodePrivatePoint(bobPrivate);
+
+    byte[] sharedOne = Curve.calculateAgreement(alicePublicKey, bobPrivateKey);
+    byte[] sharedTwo = Curve.calculateAgreement(bobPublicKey, alicePrivateKey);
+
+    assertTrue(Arrays.equals(sharedOne, shared));
+    assertTrue(Arrays.equals(sharedTwo, shared));
+  }
+
+  public void testRandomAgreements() throws InvalidKeyException {
+    for (int i=0;i<50;i++) {
+      ECKeyPair alice       = Curve.generateKeyPair();
+      ECKeyPair bob         = Curve.generateKeyPair();
+
+      byte[]    sharedAlice = Curve.calculateAgreement(bob.getPublicKey(), alice.getPrivateKey());
+      byte[]    sharedBob   = Curve.calculateAgreement(alice.getPublicKey(), bob.getPrivateKey());
+
+      assertTrue(Arrays.equals(sharedAlice, sharedBob));
+    }
+  }
+
+  public void testSignature() throws InvalidKeyException {
+    byte[] aliceIdentityPrivate = {(byte)0xc0, (byte)0x97, (byte)0x24, (byte)0x84, (byte)0x12,
+                                   (byte)0xe5, (byte)0x8b, (byte)0xf0, (byte)0x5d, (byte)0xf4,
+                                   (byte)0x87, (byte)0x96, (byte)0x82, (byte)0x05, (byte)0x13,
+                                   (byte)0x27, (byte)0x94, (byte)0x17, (byte)0x8e, (byte)0x36,
+                                   (byte)0x76, (byte)0x37, (byte)0xf5, (byte)0x81, (byte)0x8f,
+                                   (byte)0x81, (byte)0xe0, (byte)0xe6, (byte)0xce, (byte)0x73,
+                                   (byte)0xe8, (byte)0x65};
+
+    byte[] aliceIdentityPublic  = {(byte)0x05, (byte)0xab, (byte)0x7e, (byte)0x71, (byte)0x7d,
+                                   (byte)0x4a, (byte)0x16, (byte)0x3b, (byte)0x7d, (byte)0x9a,
+                                   (byte)0x1d, (byte)0x80, (byte)0x71, (byte)0xdf, (byte)0xe9,
+                                   (byte)0xdc, (byte)0xf8, (byte)0xcd, (byte)0xcd, (byte)0x1c,
+                                   (byte)0xea, (byte)0x33, (byte)0x39, (byte)0xb6, (byte)0x35,
+                                   (byte)0x6b, (byte)0xe8, (byte)0x4d, (byte)0x88, (byte)0x7e,
+                                   (byte)0x32, (byte)0x2c, (byte)0x64};
+
+    byte[] aliceEphemeralPublic = {(byte)0x05, (byte)0xed, (byte)0xce, (byte)0x9d, (byte)0x9c,
+                                   (byte)0x41, (byte)0x5c, (byte)0xa7, (byte)0x8c, (byte)0xb7,
+                                   (byte)0x25, (byte)0x2e, (byte)0x72, (byte)0xc2, (byte)0xc4,
+                                   (byte)0xa5, (byte)0x54, (byte)0xd3, (byte)0xeb, (byte)0x29,
+                                   (byte)0x48, (byte)0x5a, (byte)0x0e, (byte)0x1d, (byte)0x50,
+                                   (byte)0x31, (byte)0x18, (byte)0xd1, (byte)0xa8, (byte)0x2d,
+                                   (byte)0x99, (byte)0xfb, (byte)0x4a};
+
+    byte[] aliceSignature       = {(byte)0x5d, (byte)0xe8, (byte)0x8c, (byte)0xa9, (byte)0xa8,
+                                   (byte)0x9b, (byte)0x4a, (byte)0x11, (byte)0x5d, (byte)0xa7,
+                                   (byte)0x91, (byte)0x09, (byte)0xc6, (byte)0x7c, (byte)0x9c,
+                                   (byte)0x74, (byte)0x64, (byte)0xa3, (byte)0xe4, (byte)0x18,
+                                   (byte)0x02, (byte)0x74, (byte)0xf1, (byte)0xcb, (byte)0x8c,
+                                   (byte)0x63, (byte)0xc2, (byte)0x98, (byte)0x4e, (byte)0x28,
+                                   (byte)0x6d, (byte)0xfb, (byte)0xed, (byte)0xe8, (byte)0x2d,
+                                   (byte)0xeb, (byte)0x9d, (byte)0xcd, (byte)0x9f, (byte)0xae,
+                                   (byte)0x0b, (byte)0xfb, (byte)0xb8, (byte)0x21, (byte)0x56,
+                                   (byte)0x9b, (byte)0x3d, (byte)0x90, (byte)0x01, (byte)0xbd,
+                                   (byte)0x81, (byte)0x30, (byte)0xcd, (byte)0x11, (byte)0xd4,
+                                   (byte)0x86, (byte)0xce, (byte)0xf0, (byte)0x47, (byte)0xbd,
+                                   (byte)0x60, (byte)0xb8, (byte)0x6e, (byte)0x88};
+
+    ECPrivateKey alicePrivateKey = Curve.decodePrivatePoint(aliceIdentityPrivate);
+    ECPublicKey  alicePublicKey  = Curve.decodePoint(aliceIdentityPublic, 0);
+    ECPublicKey  aliceEphemeral  = Curve.decodePoint(aliceEphemeralPublic, 0);
+
+    if (!Curve.verifySignature(alicePublicKey, aliceEphemeral.serialize(), aliceSignature)) {
+      throw new AssertionError("Sig verification failed!");
+    }
+
+    for (int i=0;i<aliceSignature.length;i++) {
+      byte[] modifiedSignature = new byte[aliceSignature.length];
+      System.arraycopy(aliceSignature, 0, modifiedSignature, 0, modifiedSignature.length);
+
+      modifiedSignature[i] ^= 0x01;
+
+      if (Curve.verifySignature(alicePublicKey, aliceEphemeral.serialize(), modifiedSignature)) {
+        throw new AssertionError("Sig verification succeeded!");
+      }
+    }
+  }
+
+  public void testSignatureOverflow() throws InvalidKeyException {
+    ECKeyPair keys    = Curve.generateKeyPair();
+    byte[]    message = new byte[4096];
+
+    try {
+      byte[] signature = Curve.calculateSignature(keys.getPrivateKey(), message);
+      throw new InvalidKeyException("Should have asserted!");
+    } catch (AssertionError e) {
+      // Success!
+    }
+  }
+
+}
diff --git a/src/androidTest/java/org/whispersystems/test/groups/GroupCipherTest.java b/src/androidTest/java/org/whispersystems/test/groups/GroupCipherTest.java
new file mode 100644
index 00000000..6d93e921
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/groups/GroupCipherTest.java
@@ -0,0 +1,151 @@
+package org.whispersystems.test.groups;
+
+import android.test.AndroidTestCase;
+import android.util.Log;
+
+import org.whispersystems.libaxolotl.DuplicateMessageException;
+import org.whispersystems.libaxolotl.InvalidMessageException;
+import org.whispersystems.libaxolotl.LegacyMessageException;
+import org.whispersystems.libaxolotl.NoSessionException;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.groups.GroupCipher;
+import org.whispersystems.libaxolotl.groups.GroupSessionBuilder;
+import org.whispersystems.libaxolotl.protocol.SenderKeyDistributionMessage;
+import org.whispersystems.libaxolotl.util.KeyHelper;
+
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+
+public class GroupCipherTest extends AndroidTestCase {
+
+  public void testBasicEncryptDecrypt()
+      throws LegacyMessageException, DuplicateMessageException, InvalidMessageException, NoSessionException
+  {
+    InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
+    InMemorySenderKeyStore bobStore   = new InMemorySenderKeyStore();
+
+    GroupSessionBuilder aliceSessionBuilder = new GroupSessionBuilder(aliceStore);
+    GroupSessionBuilder bobSessionBuilder   = new GroupSessionBuilder(bobStore);
+
+    GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, "groupWithBobInIt");
+    GroupCipher bobGroupCipher   = new GroupCipher(bobStore, "groupWithBobInIt::aliceUserName");
+
+    byte[]    aliceSenderKey        = KeyHelper.generateSenderKey();
+    ECKeyPair aliceSenderSigningKey = KeyHelper.generateSenderSigningKey();
+    int       aliceSenderKeyId      = KeyHelper.generateSenderKeyId();
+
+    SenderKeyDistributionMessage aliceDistributionMessage =
+        aliceSessionBuilder.process("groupWithBobInIt", aliceSenderKeyId, 0,
+                                    aliceSenderKey, aliceSenderSigningKey);
+
+    bobSessionBuilder.process("groupWithBobInIt::aliceUserName", aliceDistributionMessage);
+
+    byte[] ciphertextFromAlice = aliceGroupCipher.encrypt("smert ze smert".getBytes());
+    byte[] plaintextFromAlice  = bobGroupCipher.decrypt(ciphertextFromAlice);
+
+    assertTrue(new String(plaintextFromAlice).equals("smert ze smert"));
+  }
+
+  public void testBasicRatchet()
+      throws LegacyMessageException, DuplicateMessageException, InvalidMessageException, NoSessionException
+  {
+    InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
+    InMemorySenderKeyStore bobStore   = new InMemorySenderKeyStore();
+
+    GroupSessionBuilder aliceSessionBuilder = new GroupSessionBuilder(aliceStore);
+    GroupSessionBuilder bobSessionBuilder   = new GroupSessionBuilder(bobStore);
+
+    GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, "groupWithBobInIt");
+    GroupCipher bobGroupCipher   = new GroupCipher(bobStore, "groupWithBobInIt::aliceUserName");
+
+    byte[]    aliceSenderKey        = KeyHelper.generateSenderKey();
+    ECKeyPair aliceSenderSigningKey = KeyHelper.generateSenderSigningKey();
+    int       aliceSenderKeyId      = KeyHelper.generateSenderKeyId();
+
+    SenderKeyDistributionMessage aliceDistributionMessage =
+        aliceSessionBuilder.process("groupWithBobInIt", aliceSenderKeyId, 0,
+                                    aliceSenderKey, aliceSenderSigningKey);
+
+    bobSessionBuilder.process("groupWithBobInIt::aliceUserName", aliceDistributionMessage);
+
+    byte[] ciphertextFromAlice  = aliceGroupCipher.encrypt("smert ze smert".getBytes());
+    byte[] ciphertextFromAlice2 = aliceGroupCipher.encrypt("smert ze smert2".getBytes());
+    byte[] ciphertextFromAlice3 = aliceGroupCipher.encrypt("smert ze smert3".getBytes());
+
+    byte[] plaintextFromAlice   = bobGroupCipher.decrypt(ciphertextFromAlice);
+
+    try {
+      bobGroupCipher.decrypt(ciphertextFromAlice);
+      throw new AssertionError("Should have ratcheted forward!");
+    } catch (DuplicateMessageException dme) {
+      // good
+    }
+
+    byte[] plaintextFromAlice2  = bobGroupCipher.decrypt(ciphertextFromAlice2);
+    byte[] plaintextFromAlice3  = bobGroupCipher.decrypt(ciphertextFromAlice3);
+
+    assertTrue(new String(plaintextFromAlice).equals("smert ze smert"));
+    assertTrue(new String(plaintextFromAlice2).equals("smert ze smert2"));
+    assertTrue(new String(plaintextFromAlice3).equals("smert ze smert3"));
+  }
+
+  public void testOutOfOrder()
+      throws LegacyMessageException, DuplicateMessageException, InvalidMessageException, NoSessionException
+  {
+    InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
+    InMemorySenderKeyStore bobStore   = new InMemorySenderKeyStore();
+
+    GroupSessionBuilder aliceSessionBuilder = new GroupSessionBuilder(aliceStore);
+    GroupSessionBuilder bobSessionBuilder   = new GroupSessionBuilder(bobStore);
+
+    GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, "groupWithBobInIt");
+    GroupCipher bobGroupCipher   = new GroupCipher(bobStore, "groupWithBobInIt::aliceUserName");
+
+    byte[]    aliceSenderKey        = KeyHelper.generateSenderKey();
+    ECKeyPair aliceSenderSigningKey = KeyHelper.generateSenderSigningKey();
+    int       aliceSenderKeyId      = KeyHelper.generateSenderKeyId();
+
+    SenderKeyDistributionMessage aliceDistributionMessage =
+        aliceSessionBuilder.process("groupWithBobInIt", aliceSenderKeyId, 0,
+                                    aliceSenderKey, aliceSenderSigningKey);
+
+    bobSessionBuilder.process("groupWithBobInIt::aliceUserName", aliceDistributionMessage);
+
+
+    ArrayList<byte[]> ciphertexts = new ArrayList<>(100);
+
+    for (int i=0;i<100;i++) {
+      ciphertexts.add(aliceGroupCipher.encrypt("up the punks".getBytes()));
+    }
+
+    while (ciphertexts.size() > 0) {
+      int    index      = randomInt() % ciphertexts.size();
+      byte[] ciphertext = ciphertexts.remove(index);
+      byte[] plaintext  = bobGroupCipher.decrypt(ciphertext);
+
+      assertTrue(new String(plaintext).equals("up the punks"));
+    }
+  }
+
+  public void testEncryptNoSession() {
+    InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
+    GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, "groupWithBobInIt");
+    try {
+      aliceGroupCipher.encrypt("up the punks".getBytes());
+      throw new AssertionError("Should have failed!");
+    } catch (NoSessionException nse) {
+      // good
+    }
+  }
+
+  private int randomInt() {
+    try {
+      return SecureRandom.getInstance("SHA1PRNG").nextInt(Integer.MAX_VALUE);
+    } catch (NoSuchAlgorithmException e) {
+      throw new AssertionError(e);
+    }
+  }
+}
diff --git a/src/androidTest/java/org/whispersystems/test/groups/InMemorySenderKeyStore.java b/src/androidTest/java/org/whispersystems/test/groups/InMemorySenderKeyStore.java
new file mode 100644
index 00000000..450d802d
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/groups/InMemorySenderKeyStore.java
@@ -0,0 +1,33 @@
+package org.whispersystems.test.groups;
+
+import org.whispersystems.libaxolotl.groups.state.SenderKeyRecord;
+import org.whispersystems.libaxolotl.groups.state.SenderKeyStore;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+public class InMemorySenderKeyStore implements SenderKeyStore {
+
+  private final Map<String, SenderKeyRecord> store = new HashMap<>();
+
+  @Override
+  public void storeSenderKey(String senderKeyId, SenderKeyRecord record) {
+    store.put(senderKeyId, record);
+  }
+
+  @Override
+  public SenderKeyRecord loadSenderKey(String senderKeyId) {
+    try {
+      SenderKeyRecord record = store.get(senderKeyId);
+
+      if (record == null) {
+        return new SenderKeyRecord();
+      } else {
+        return new SenderKeyRecord(record.serialize());
+      }
+    } catch (IOException e) {
+      throw new AssertionError(e);
+    }
+  }
+}
diff --git a/src/androidTest/java/org/whispersystems/test/kdf/HKDFTest.java b/src/androidTest/java/org/whispersystems/test/kdf/HKDFTest.java
new file mode 100644
index 00000000..079bc4fa
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/kdf/HKDFTest.java
@@ -0,0 +1,139 @@
+package org.whispersystems.test.kdf;
+
+import android.test.AndroidTestCase;
+
+import org.whispersystems.libaxolotl.kdf.HKDF;
+
+import java.util.Arrays;
+
+public class HKDFTest extends AndroidTestCase {
+
+  public void testVectorV3() {
+    byte[] ikm = {0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                  0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                  0x0b, 0x0b};
+
+    byte[] salt = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
+                   0x0a, 0x0b, 0x0c};
+
+    byte[] info = {(byte) 0xf0, (byte) 0xf1, (byte) 0xf2, (byte) 0xf3, (byte) 0xf4,
+                   (byte) 0xf5, (byte) 0xf6, (byte) 0xf7, (byte) 0xf8, (byte) 0xf9};
+
+    byte[] okm = {(byte) 0x3c, (byte) 0xb2, (byte) 0x5f, (byte) 0x25, (byte) 0xfa,
+                  (byte) 0xac, (byte) 0xd5, (byte) 0x7a, (byte) 0x90, (byte) 0x43,
+                  (byte) 0x4f, (byte) 0x64, (byte) 0xd0, (byte) 0x36, (byte) 0x2f,
+                  (byte) 0x2a, (byte) 0x2d, (byte) 0x2d, (byte) 0x0a, (byte) 0x90,
+                  (byte) 0xcf, (byte) 0x1a, (byte) 0x5a, (byte) 0x4c, (byte) 0x5d,
+                  (byte) 0xb0, (byte) 0x2d, (byte) 0x56, (byte) 0xec, (byte) 0xc4,
+                  (byte) 0xc5, (byte) 0xbf, (byte) 0x34, (byte) 0x00, (byte) 0x72,
+                  (byte) 0x08, (byte) 0xd5, (byte) 0xb8, (byte) 0x87, (byte) 0x18,
+                  (byte) 0x58, (byte) 0x65};
+
+    byte[] actualOutput = HKDF.createFor(3).deriveSecrets(ikm, salt, info, 42);
+
+    assertTrue(Arrays.equals(okm, actualOutput));
+  }
+
+  public void testVectorLongV3() {
+    byte[] ikm  = {(byte) 0x00, (byte) 0x01, (byte) 0x02, (byte) 0x03, (byte) 0x04,
+                   (byte) 0x05, (byte) 0x06, (byte) 0x07, (byte) 0x08, (byte) 0x09,
+                   (byte) 0x0a, (byte) 0x0b, (byte) 0x0c, (byte) 0x0d, (byte) 0x0e,
+                   (byte) 0x0f, (byte) 0x10, (byte) 0x11, (byte) 0x12, (byte) 0x13,
+                   (byte) 0x14, (byte) 0x15, (byte) 0x16, (byte) 0x17, (byte) 0x18,
+                   (byte) 0x19, (byte) 0x1a, (byte) 0x1b, (byte) 0x1c, (byte) 0x1d,
+                   (byte) 0x1e, (byte) 0x1f, (byte) 0x20, (byte) 0x21, (byte) 0x22,
+                   (byte) 0x23, (byte) 0x24, (byte) 0x25, (byte) 0x26, (byte) 0x27,
+                   (byte) 0x28, (byte) 0x29, (byte) 0x2a, (byte) 0x2b, (byte) 0x2c,
+                   (byte) 0x2d, (byte) 0x2e, (byte) 0x2f, (byte) 0x30, (byte) 0x31,
+                   (byte) 0x32, (byte) 0x33, (byte) 0x34, (byte) 0x35, (byte) 0x36,
+                   (byte) 0x37, (byte) 0x38, (byte) 0x39, (byte) 0x3a, (byte) 0x3b,
+                   (byte) 0x3c, (byte) 0x3d, (byte) 0x3e, (byte) 0x3f, (byte) 0x40,
+                   (byte) 0x41, (byte) 0x42, (byte) 0x43, (byte) 0x44, (byte) 0x45,
+                   (byte) 0x46, (byte) 0x47, (byte) 0x48, (byte) 0x49, (byte) 0x4a,
+                   (byte) 0x4b, (byte) 0x4c, (byte) 0x4d, (byte) 0x4e, (byte) 0x4f};
+
+    byte[] salt = {(byte) 0x60, (byte) 0x61, (byte) 0x62, (byte) 0x63, (byte) 0x64,
+                   (byte) 0x65, (byte) 0x66, (byte) 0x67, (byte) 0x68, (byte) 0x69,
+                   (byte) 0x6a, (byte) 0x6b, (byte) 0x6c, (byte) 0x6d, (byte) 0x6e,
+                   (byte) 0x6f, (byte) 0x70, (byte) 0x71, (byte) 0x72, (byte) 0x73,
+                   (byte) 0x74, (byte) 0x75, (byte) 0x76, (byte) 0x77, (byte) 0x78,
+                   (byte) 0x79, (byte) 0x7a, (byte) 0x7b, (byte) 0x7c, (byte) 0x7d,
+                   (byte) 0x7e, (byte) 0x7f, (byte) 0x80, (byte) 0x81, (byte) 0x82,
+                   (byte) 0x83, (byte) 0x84, (byte) 0x85, (byte) 0x86, (byte) 0x87,
+                   (byte) 0x88, (byte) 0x89, (byte) 0x8a, (byte) 0x8b, (byte) 0x8c,
+                   (byte) 0x8d, (byte) 0x8e, (byte) 0x8f, (byte) 0x90, (byte) 0x91,
+                   (byte) 0x92, (byte) 0x93, (byte) 0x94, (byte) 0x95, (byte) 0x96,
+                   (byte) 0x97, (byte) 0x98, (byte) 0x99, (byte) 0x9a, (byte) 0x9b,
+                   (byte) 0x9c, (byte) 0x9d, (byte) 0x9e, (byte) 0x9f, (byte) 0xa0,
+                   (byte) 0xa1, (byte) 0xa2, (byte) 0xa3, (byte) 0xa4, (byte) 0xa5,
+                   (byte) 0xa6, (byte) 0xa7, (byte) 0xa8, (byte) 0xa9, (byte) 0xaa,
+                   (byte) 0xab, (byte) 0xac, (byte) 0xad, (byte) 0xae, (byte) 0xaf};
+
+    byte[] info = {(byte) 0xb0, (byte) 0xb1, (byte) 0xb2, (byte) 0xb3, (byte) 0xb4,
+                   (byte) 0xb5, (byte) 0xb6, (byte) 0xb7, (byte) 0xb8, (byte) 0xb9,
+                   (byte) 0xba, (byte) 0xbb, (byte) 0xbc, (byte) 0xbd, (byte) 0xbe,
+                   (byte) 0xbf, (byte) 0xc0, (byte) 0xc1, (byte) 0xc2, (byte) 0xc3,
+                   (byte) 0xc4, (byte) 0xc5, (byte) 0xc6, (byte) 0xc7, (byte) 0xc8,
+                   (byte) 0xc9, (byte) 0xca, (byte) 0xcb, (byte) 0xcc, (byte) 0xcd,
+                   (byte) 0xce, (byte) 0xcf, (byte) 0xd0, (byte) 0xd1, (byte) 0xd2,
+                   (byte) 0xd3, (byte) 0xd4, (byte) 0xd5, (byte) 0xd6, (byte) 0xd7,
+                   (byte) 0xd8, (byte) 0xd9, (byte) 0xda, (byte) 0xdb, (byte) 0xdc,
+                   (byte) 0xdd, (byte) 0xde, (byte) 0xdf, (byte) 0xe0, (byte) 0xe1,
+                   (byte) 0xe2, (byte) 0xe3, (byte) 0xe4, (byte) 0xe5, (byte) 0xe6,
+                   (byte) 0xe7, (byte) 0xe8, (byte) 0xe9, (byte) 0xea, (byte) 0xeb,
+                   (byte) 0xec, (byte) 0xed, (byte) 0xee, (byte) 0xef, (byte) 0xf0,
+                   (byte) 0xf1, (byte) 0xf2, (byte) 0xf3, (byte) 0xf4, (byte) 0xf5,
+                   (byte) 0xf6, (byte) 0xf7, (byte) 0xf8, (byte) 0xf9, (byte) 0xfa,
+                   (byte) 0xfb, (byte) 0xfc, (byte) 0xfd, (byte) 0xfe, (byte) 0xff};
+
+    byte[] okm  = {(byte) 0xb1, (byte) 0x1e, (byte) 0x39, (byte) 0x8d, (byte) 0xc8,
+                   (byte) 0x03, (byte) 0x27, (byte) 0xa1, (byte) 0xc8, (byte) 0xe7,
+                   (byte) 0xf7, (byte) 0x8c, (byte) 0x59, (byte) 0x6a, (byte) 0x49,
+                   (byte) 0x34, (byte) 0x4f, (byte) 0x01, (byte) 0x2e, (byte) 0xda,
+                   (byte) 0x2d, (byte) 0x4e, (byte) 0xfa, (byte) 0xd8, (byte) 0xa0,
+                   (byte) 0x50, (byte) 0xcc, (byte) 0x4c, (byte) 0x19, (byte) 0xaf,
+                   (byte) 0xa9, (byte) 0x7c, (byte) 0x59, (byte) 0x04, (byte) 0x5a,
+                   (byte) 0x99, (byte) 0xca, (byte) 0xc7, (byte) 0x82, (byte) 0x72,
+                   (byte) 0x71, (byte) 0xcb, (byte) 0x41, (byte) 0xc6, (byte) 0x5e,
+                   (byte) 0x59, (byte) 0x0e, (byte) 0x09, (byte) 0xda, (byte) 0x32,
+                   (byte) 0x75, (byte) 0x60, (byte) 0x0c, (byte) 0x2f, (byte) 0x09,
+                   (byte) 0xb8, (byte) 0x36, (byte) 0x77, (byte) 0x93, (byte) 0xa9,
+                   (byte) 0xac, (byte) 0xa3, (byte) 0xdb, (byte) 0x71, (byte) 0xcc,
+                   (byte) 0x30, (byte) 0xc5, (byte) 0x81, (byte) 0x79, (byte) 0xec,
+                   (byte) 0x3e, (byte) 0x87, (byte) 0xc1, (byte) 0x4c, (byte) 0x01,
+                   (byte) 0xd5, (byte) 0xc1, (byte) 0xf3, (byte) 0x43, (byte) 0x4f,
+                   (byte) 0x1d, (byte) 0x87};
+
+    byte[] actualOutput = HKDF.createFor(3).deriveSecrets(ikm, salt, info, 82);
+    assertTrue(Arrays.equals(okm, actualOutput));
+  }
+
+  public void testVectorV2() {
+    byte[] ikm = {0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                  0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+                  0x0b, 0x0b};
+
+    byte[] salt = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
+                   0x0a, 0x0b, 0x0c};
+
+    byte[] info = {(byte)0xf0, (byte)0xf1, (byte)0xf2, (byte)0xf3, (byte)0xf4,
+                   (byte)0xf5, (byte)0xf6, (byte)0xf7, (byte)0xf8, (byte)0xf9};
+
+    byte[] okm = {(byte)0x6e, (byte)0xc2, (byte)0x55, (byte)0x6d, (byte)0x5d,
+                  (byte)0x7b, (byte)0x1d, (byte)0x81, (byte)0xde, (byte)0xe4,
+                  (byte)0x22, (byte)0x2a, (byte)0xd7, (byte)0x48, (byte)0x36,
+                  (byte)0x95, (byte)0xdd, (byte)0xc9, (byte)0x8f, (byte)0x4f,
+                  (byte)0x5f, (byte)0xab, (byte)0xc0, (byte)0xe0, (byte)0x20,
+                  (byte)0x5d, (byte)0xc2, (byte)0xef, (byte)0x87, (byte)0x52,
+                  (byte)0xd4, (byte)0x1e, (byte)0x04, (byte)0xe2, (byte)0xe2,
+                  (byte)0x11, (byte)0x01, (byte)0xc6, (byte)0x8f, (byte)0xf0,
+                  (byte)0x93, (byte)0x94, (byte)0xb8, (byte)0xad, (byte)0x0b,
+                  (byte)0xdc, (byte)0xb9, (byte)0x60, (byte)0x9c, (byte)0xd4,
+                  (byte)0xee, (byte)0x82, (byte)0xac, (byte)0x13, (byte)0x19,
+                  (byte)0x9b, (byte)0x4a, (byte)0xa9, (byte)0xfd, (byte)0xa8,
+                  (byte)0x99, (byte)0xda, (byte)0xeb, (byte)0xec};
+
+    byte[] actualOutput = HKDF.createFor(2).deriveSecrets(ikm, salt, info, 64);
+    assertTrue(Arrays.equals(okm, actualOutput));
+  }
+}
diff --git a/src/androidTest/java/org/whispersystems/test/ratchet/ChainKeyTest.java b/src/androidTest/java/org/whispersystems/test/ratchet/ChainKeyTest.java
new file mode 100644
index 00000000..1197f3eb
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/ratchet/ChainKeyTest.java
@@ -0,0 +1,59 @@
+package org.whispersystems.test.ratchet;
+
+import android.test.AndroidTestCase;
+
+import org.whispersystems.libaxolotl.kdf.HKDF;
+import org.whispersystems.libaxolotl.ratchet.ChainKey;
+
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+
+public class ChainKeyTest extends AndroidTestCase {
+
+  public void testChainKeyDerivationV2() throws NoSuchAlgorithmException {
+
+    byte[] seed         = {(byte) 0x8a, (byte) 0xb7, (byte) 0x2d, (byte) 0x6f, (byte) 0x4c,
+                           (byte) 0xc5, (byte) 0xac, (byte) 0x0d, (byte) 0x38, (byte) 0x7e,
+                           (byte) 0xaf, (byte) 0x46, (byte) 0x33, (byte) 0x78, (byte) 0xdd,
+                           (byte) 0xb2, (byte) 0x8e, (byte) 0xdd, (byte) 0x07, (byte) 0x38,
+                           (byte) 0x5b, (byte) 0x1c, (byte) 0xb0, (byte) 0x12, (byte) 0x50,
+                           (byte) 0xc7, (byte) 0x15, (byte) 0x98, (byte) 0x2e, (byte) 0x7a,
+                           (byte) 0xd4, (byte) 0x8f};
+
+    byte[] messageKey   = {(byte) 0x02, (byte) 0xa9, (byte) 0xaa, (byte) 0x6c, (byte) 0x7d,
+                           (byte) 0xbd, (byte) 0x64, (byte) 0xf9, (byte) 0xd3, (byte) 0xaa,
+                           (byte) 0x92, (byte) 0xf9, (byte) 0x2a, (byte) 0x27, (byte) 0x7b,
+                           (byte) 0xf5, (byte) 0x46, (byte) 0x09, (byte) 0xda, (byte) 0xdf,
+                           (byte) 0x0b, (byte) 0x00, (byte) 0x82, (byte) 0x8a, (byte) 0xcf,
+                           (byte) 0xc6, (byte) 0x1e, (byte) 0x3c, (byte) 0x72, (byte) 0x4b,
+                           (byte) 0x84, (byte) 0xa7};
+
+    byte[] macKey       = {(byte) 0xbf, (byte) 0xbe, (byte) 0x5e, (byte) 0xfb, (byte) 0x60,
+                           (byte) 0x30, (byte) 0x30, (byte) 0x52, (byte) 0x67, (byte) 0x42,
+                           (byte) 0xe3, (byte) 0xee, (byte) 0x89, (byte) 0xc7, (byte) 0x02,
+                           (byte) 0x4e, (byte) 0x88, (byte) 0x4e, (byte) 0x44, (byte) 0x0f,
+                           (byte) 0x1f, (byte) 0xf3, (byte) 0x76, (byte) 0xbb, (byte) 0x23,
+                           (byte) 0x17, (byte) 0xb2, (byte) 0xd6, (byte) 0x4d, (byte) 0xeb,
+                           (byte) 0x7c, (byte) 0x83};
+
+    byte[] nextChainKey = {(byte) 0x28, (byte) 0xe8, (byte) 0xf8, (byte) 0xfe, (byte) 0xe5,
+                           (byte) 0x4b, (byte) 0x80, (byte) 0x1e, (byte) 0xef, (byte) 0x7c,
+                           (byte) 0x5c, (byte) 0xfb, (byte) 0x2f, (byte) 0x17, (byte) 0xf3,
+                           (byte) 0x2c, (byte) 0x7b, (byte) 0x33, (byte) 0x44, (byte) 0x85,
+                           (byte) 0xbb, (byte) 0xb7, (byte) 0x0f, (byte) 0xac, (byte) 0x6e,
+                           (byte) 0xc1, (byte) 0x03, (byte) 0x42, (byte) 0xa2, (byte) 0x46,
+                           (byte) 0xd1, (byte) 0x5d};
+
+    ChainKey chainKey = new ChainKey(HKDF.createFor(2), seed, 0);
+
+    assertTrue(Arrays.equals(chainKey.getKey(), seed));
+    assertTrue(Arrays.equals(chainKey.getMessageKeys().getCipherKey().getEncoded(), messageKey));
+    assertTrue(Arrays.equals(chainKey.getMessageKeys().getMacKey().getEncoded(), macKey));
+    assertTrue(Arrays.equals(chainKey.getNextChainKey().getKey(), nextChainKey));
+    assertTrue(chainKey.getIndex() == 0);
+    assertTrue(chainKey.getMessageKeys().getCounter() == 0);
+    assertTrue(chainKey.getNextChainKey().getIndex() == 1);
+    assertTrue(chainKey.getNextChainKey().getMessageKeys().getCounter() == 1);
+  }
+
+}
diff --git a/src/androidTest/java/org/whispersystems/test/ratchet/RatchetingSessionTest.java b/src/androidTest/java/org/whispersystems/test/ratchet/RatchetingSessionTest.java
new file mode 100644
index 00000000..311aff90
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/ratchet/RatchetingSessionTest.java
@@ -0,0 +1,236 @@
+package org.whispersystems.test.ratchet;
+
+import android.test.AndroidTestCase;
+import android.util.Log;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.IdentityKeyPair;
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPrivateKey;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.ratchet.AliceAxolotlParameters;
+import org.whispersystems.libaxolotl.ratchet.BobAxolotlParameters;
+import org.whispersystems.libaxolotl.ratchet.RatchetingSession;
+import org.whispersystems.libaxolotl.state.SessionState;
+import org.whispersystems.libaxolotl.util.Hex;
+import org.whispersystems.libaxolotl.util.guava.Optional;
+
+import java.util.Arrays;
+
+public class RatchetingSessionTest extends AndroidTestCase {
+
+  public void testRatchetingSessionAsBob() throws InvalidKeyException {
+    byte[] bobPublic             = {(byte) 0x05, (byte) 0x2c, (byte) 0xb4, (byte) 0x97,
+                                    (byte) 0x76, (byte) 0xb8, (byte) 0x77, (byte) 0x02,
+                                    (byte) 0x05, (byte) 0x74, (byte) 0x5a, (byte) 0x3a,
+                                    (byte) 0x6e, (byte) 0x24, (byte) 0xf5, (byte) 0x79,
+                                    (byte) 0xcd, (byte) 0xb4, (byte) 0xba, (byte) 0x7a,
+                                    (byte) 0x89, (byte) 0x04, (byte) 0x10, (byte) 0x05,
+                                    (byte) 0x92, (byte) 0x8e, (byte) 0xbb, (byte) 0xad,
+                                    (byte) 0xc9, (byte) 0xc0, (byte) 0x5a, (byte) 0xd4,
+                                    (byte) 0x58};
+
+    byte[] bobPrivate            = {(byte) 0xa1, (byte) 0xca, (byte) 0xb4, (byte) 0x8f,
+                                    (byte) 0x7c, (byte) 0x89, (byte) 0x3f, (byte) 0xaf,
+                                    (byte) 0xa9, (byte) 0x88, (byte) 0x0a, (byte) 0x28,
+                                    (byte) 0xc3, (byte) 0xb4, (byte) 0x99, (byte) 0x9d,
+                                    (byte) 0x28, (byte) 0xd6, (byte) 0x32, (byte) 0x95,
+                                    (byte) 0x62, (byte) 0xd2, (byte) 0x7a, (byte) 0x4e,
+                                    (byte) 0xa4, (byte) 0xe2, (byte) 0x2e, (byte) 0x9f,
+                                    (byte) 0xf1, (byte) 0xbd, (byte) 0xd6, (byte) 0x5a};
+
+    byte[] bobIdentityPublic     = {(byte) 0x05, (byte) 0xf1, (byte) 0xf4, (byte) 0x38,
+                                    (byte) 0x74, (byte) 0xf6, (byte) 0x96, (byte) 0x69,
+                                    (byte) 0x56, (byte) 0xc2, (byte) 0xdd, (byte) 0x47,
+                                    (byte) 0x3f, (byte) 0x8f, (byte) 0xa1, (byte) 0x5a,
+                                    (byte) 0xde, (byte) 0xb7, (byte) 0x1d, (byte) 0x1c,
+                                    (byte) 0xb9, (byte) 0x91, (byte) 0xb2, (byte) 0x34,
+                                    (byte) 0x16, (byte) 0x92, (byte) 0x32, (byte) 0x4c,
+                                    (byte) 0xef, (byte) 0xb1, (byte) 0xc5, (byte) 0xe6,
+                                    (byte) 0x26};
+
+    byte[] bobIdentityPrivate    = {(byte) 0x48, (byte) 0x75, (byte) 0xcc, (byte) 0x69,
+                                    (byte) 0xdd, (byte) 0xf8, (byte) 0xea, (byte) 0x07,
+                                    (byte) 0x19, (byte) 0xec, (byte) 0x94, (byte) 0x7d,
+                                    (byte) 0x61, (byte) 0x08, (byte) 0x11, (byte) 0x35,
+                                    (byte) 0x86, (byte) 0x8d, (byte) 0x5f, (byte) 0xd8,
+                                    (byte) 0x01, (byte) 0xf0, (byte) 0x2c, (byte) 0x02,
+                                    (byte) 0x25, (byte) 0xe5, (byte) 0x16, (byte) 0xdf,
+                                    (byte) 0x21, (byte) 0x56, (byte) 0x60, (byte) 0x5e};
+
+    byte[] aliceBasePublic       = {(byte) 0x05, (byte) 0x47, (byte) 0x2d, (byte) 0x1f,
+                                    (byte) 0xb1, (byte) 0xa9, (byte) 0x86, (byte) 0x2c,
+                                    (byte) 0x3a, (byte) 0xf6, (byte) 0xbe, (byte) 0xac,
+                                    (byte) 0xa8, (byte) 0x92, (byte) 0x02, (byte) 0x77,
+                                    (byte) 0xe2, (byte) 0xb2, (byte) 0x6f, (byte) 0x4a,
+                                    (byte) 0x79, (byte) 0x21, (byte) 0x3e, (byte) 0xc7,
+                                    (byte) 0xc9, (byte) 0x06, (byte) 0xae, (byte) 0xb3,
+                                    (byte) 0x5e, (byte) 0x03, (byte) 0xcf, (byte) 0x89,
+                                    (byte) 0x50};
+
+    byte[] aliceEphemeralPublic  = {(byte) 0x05, (byte) 0x6c, (byte) 0x3e, (byte) 0x0d,
+                                    (byte) 0x1f, (byte) 0x52, (byte) 0x02, (byte) 0x83,
+                                    (byte) 0xef, (byte) 0xcc, (byte) 0x55, (byte) 0xfc,
+                                    (byte) 0xa5, (byte) 0xe6, (byte) 0x70, (byte) 0x75,
+                                    (byte) 0xb9, (byte) 0x04, (byte) 0x00, (byte) 0x7f,
+                                    (byte) 0x18, (byte) 0x81, (byte) 0xd1, (byte) 0x51,
+                                    (byte) 0xaf, (byte) 0x76, (byte) 0xdf, (byte) 0x18,
+                                    (byte) 0xc5, (byte) 0x1d, (byte) 0x29, (byte) 0xd3,
+                                    (byte) 0x4b};
+
+    byte[] aliceIdentityPublic   = {(byte) 0x05, (byte) 0xb4, (byte) 0xa8, (byte) 0x45,
+                                    (byte) 0x56, (byte) 0x60, (byte) 0xad, (byte) 0xa6,
+                                    (byte) 0x5b, (byte) 0x40, (byte) 0x10, (byte) 0x07,
+                                    (byte) 0xf6, (byte) 0x15, (byte) 0xe6, (byte) 0x54,
+                                    (byte) 0x04, (byte) 0x17, (byte) 0x46, (byte) 0x43,
+                                    (byte) 0x2e, (byte) 0x33, (byte) 0x39, (byte) 0xc6,
+                                    (byte) 0x87, (byte) 0x51, (byte) 0x49, (byte) 0xbc,
+                                    (byte) 0xee, (byte) 0xfc, (byte) 0xb4, (byte) 0x2b,
+                                    (byte) 0x4a};
+
+    byte[] senderChain           = {(byte)0xd2, (byte)0x2f, (byte)0xd5, (byte)0x6d, (byte)0x3f,
+                                    (byte)0xec, (byte)0x81, (byte)0x9c, (byte)0xf4, (byte)0xc3,
+                                    (byte)0xd5, (byte)0x0c, (byte)0x56, (byte)0xed, (byte)0xfb,
+                                    (byte)0x1c, (byte)0x28, (byte)0x0a, (byte)0x1b, (byte)0x31,
+                                    (byte)0x96, (byte)0x45, (byte)0x37, (byte)0xf1, (byte)0xd1,
+                                    (byte)0x61, (byte)0xe1, (byte)0xc9, (byte)0x31, (byte)0x48,
+                                    (byte)0xe3, (byte)0x6b};
+
+    IdentityKey     bobIdentityKeyPublic   = new IdentityKey(bobIdentityPublic, 0);
+    ECPrivateKey    bobIdentityKeyPrivate  = Curve.decodePrivatePoint(bobIdentityPrivate);
+    IdentityKeyPair bobIdentityKey         = new IdentityKeyPair(bobIdentityKeyPublic, bobIdentityKeyPrivate);
+    ECPublicKey     bobEphemeralPublicKey  = Curve.decodePoint(bobPublic, 0);
+    ECPrivateKey    bobEphemeralPrivateKey = Curve.decodePrivatePoint(bobPrivate);
+    ECKeyPair       bobEphemeralKey        = new ECKeyPair(bobEphemeralPublicKey, bobEphemeralPrivateKey);
+    ECKeyPair       bobBaseKey             = bobEphemeralKey;
+
+    ECPublicKey     aliceBasePublicKey       = Curve.decodePoint(aliceBasePublic, 0);
+    ECPublicKey     aliceEphemeralPublicKey  = Curve.decodePoint(aliceEphemeralPublic, 0);
+    IdentityKey     aliceIdentityPublicKey   = new IdentityKey(aliceIdentityPublic, 0);
+
+    BobAxolotlParameters parameters = BobAxolotlParameters.newBuilder()
+        .setOurIdentityKey(bobIdentityKey)
+        .setOurSignedPreKey(bobBaseKey)
+        .setOurRatchetKey(bobEphemeralKey)
+        .setOurOneTimePreKey(Optional.<ECKeyPair>absent())
+        .setTheirIdentityKey(aliceIdentityPublicKey)
+        .setTheirBaseKey(aliceBasePublicKey)
+        .create();
+
+    SessionState session = new SessionState();
+
+    RatchetingSession.initializeSession(session, 2, parameters);
+
+    assertTrue(session.getLocalIdentityKey().equals(bobIdentityKey.getPublicKey()));
+    assertTrue(session.getRemoteIdentityKey().equals(aliceIdentityPublicKey));
+    assertTrue(Arrays.equals(session.getSenderChainKey().getKey(), senderChain));
+  }
+
+  public void testRatchetingSessionAsAlice() throws InvalidKeyException {
+    byte[] bobPublic             = {(byte) 0x05, (byte) 0x2c, (byte) 0xb4, (byte) 0x97, (byte) 0x76,
+                                    (byte) 0xb8, (byte) 0x77, (byte) 0x02, (byte) 0x05, (byte) 0x74,
+                                    (byte) 0x5a, (byte) 0x3a, (byte) 0x6e, (byte) 0x24, (byte) 0xf5,
+                                    (byte) 0x79, (byte) 0xcd, (byte) 0xb4, (byte) 0xba, (byte) 0x7a,
+                                    (byte) 0x89, (byte) 0x04, (byte) 0x10, (byte) 0x05, (byte) 0x92,
+                                    (byte) 0x8e, (byte) 0xbb, (byte) 0xad, (byte) 0xc9, (byte) 0xc0,
+                                    (byte) 0x5a, (byte) 0xd4, (byte) 0x58};
+
+    byte[] bobIdentityPublic     = {(byte) 0x05, (byte) 0xf1, (byte) 0xf4, (byte) 0x38, (byte) 0x74,
+                                    (byte) 0xf6, (byte) 0x96, (byte) 0x69, (byte) 0x56, (byte) 0xc2,
+                                    (byte) 0xdd, (byte) 0x47, (byte) 0x3f, (byte) 0x8f, (byte) 0xa1,
+                                    (byte) 0x5a, (byte) 0xde, (byte) 0xb7, (byte) 0x1d, (byte) 0x1c,
+                                    (byte) 0xb9, (byte) 0x91, (byte) 0xb2, (byte) 0x34, (byte) 0x16,
+                                    (byte) 0x92, (byte) 0x32, (byte) 0x4c, (byte) 0xef, (byte) 0xb1,
+                                    (byte) 0xc5, (byte) 0xe6, (byte) 0x26};
+
+    byte[] aliceBasePublic       = {(byte) 0x05, (byte) 0x47, (byte) 0x2d, (byte) 0x1f, (byte) 0xb1,
+                                    (byte) 0xa9, (byte) 0x86, (byte) 0x2c, (byte) 0x3a, (byte) 0xf6,
+                                    (byte) 0xbe, (byte) 0xac, (byte) 0xa8, (byte) 0x92, (byte) 0x02,
+                                    (byte) 0x77, (byte) 0xe2, (byte) 0xb2, (byte) 0x6f, (byte) 0x4a,
+                                    (byte) 0x79, (byte) 0x21, (byte) 0x3e, (byte) 0xc7, (byte) 0xc9,
+                                    (byte) 0x06, (byte) 0xae, (byte) 0xb3, (byte) 0x5e, (byte) 0x03,
+                                    (byte) 0xcf, (byte) 0x89, (byte) 0x50};
+
+    byte[] aliceBasePrivate      = {(byte) 0x11, (byte) 0xae, (byte) 0x7c, (byte) 0x64, (byte) 0xd1,
+                                    (byte) 0xe6, (byte) 0x1c, (byte) 0xd5, (byte) 0x96, (byte) 0xb7,
+                                    (byte) 0x6a, (byte) 0x0d, (byte) 0xb5, (byte) 0x01, (byte) 0x26,
+                                    (byte) 0x73, (byte) 0x39, (byte) 0x1c, (byte) 0xae, (byte) 0x66,
+                                    (byte) 0xed, (byte) 0xbf, (byte) 0xcf, (byte) 0x07, (byte) 0x3b,
+                                    (byte) 0x4d, (byte) 0xa8, (byte) 0x05, (byte) 0x16, (byte) 0xa4,
+                                    (byte) 0x74, (byte) 0x49};
+
+    byte[] aliceEphemeralPublic  = {(byte) 0x05, (byte) 0x6c, (byte) 0x3e, (byte) 0x0d, (byte) 0x1f,
+                                    (byte) 0x52, (byte) 0x02, (byte) 0x83, (byte) 0xef, (byte) 0xcc,
+                                    (byte) 0x55, (byte) 0xfc, (byte) 0xa5, (byte) 0xe6, (byte) 0x70,
+                                    (byte) 0x75, (byte) 0xb9, (byte) 0x04, (byte) 0x00, (byte) 0x7f,
+                                    (byte) 0x18, (byte) 0x81, (byte) 0xd1, (byte) 0x51, (byte) 0xaf,
+                                    (byte) 0x76, (byte) 0xdf, (byte) 0x18, (byte) 0xc5, (byte) 0x1d,
+                                    (byte) 0x29, (byte) 0xd3, (byte) 0x4b};
+
+    byte[] aliceEphemeralPrivate = {(byte) 0xd1, (byte) 0xba, (byte) 0x38, (byte) 0xce, (byte) 0xa9,
+                                    (byte) 0x17, (byte) 0x43, (byte) 0xd3, (byte) 0x39, (byte) 0x39,
+                                    (byte) 0xc3, (byte) 0x3c, (byte) 0x84, (byte) 0x98, (byte) 0x65,
+                                    (byte) 0x09, (byte) 0x28, (byte) 0x01, (byte) 0x61, (byte) 0xb8,
+                                    (byte) 0xb6, (byte) 0x0f, (byte) 0xc7, (byte) 0x87, (byte) 0x0c,
+                                    (byte) 0x59, (byte) 0x9c, (byte) 0x1d, (byte) 0x46, (byte) 0x20,
+                                    (byte) 0x12, (byte) 0x48};
+
+    byte[] aliceIdentityPublic   = {(byte) 0x05, (byte) 0xb4, (byte) 0xa8, (byte) 0x45, (byte) 0x56,
+                                    (byte) 0x60, (byte) 0xad, (byte) 0xa6, (byte) 0x5b, (byte) 0x40,
+                                    (byte) 0x10, (byte) 0x07, (byte) 0xf6, (byte) 0x15, (byte) 0xe6,
+                                    (byte) 0x54, (byte) 0x04, (byte) 0x17, (byte) 0x46, (byte) 0x43,
+                                    (byte) 0x2e, (byte) 0x33, (byte) 0x39, (byte) 0xc6, (byte) 0x87,
+                                    (byte) 0x51, (byte) 0x49, (byte) 0xbc, (byte) 0xee, (byte) 0xfc,
+                                    (byte) 0xb4, (byte) 0x2b, (byte) 0x4a};
+
+    byte[] aliceIdentityPrivate  = {(byte) 0x90, (byte) 0x40, (byte) 0xf0, (byte) 0xd4, (byte) 0xe0,
+                                    (byte) 0x9c, (byte) 0xf3, (byte) 0x8f, (byte) 0x6d, (byte) 0xc7,
+                                    (byte) 0xc1, (byte) 0x37, (byte) 0x79, (byte) 0xc9, (byte) 0x08,
+                                    (byte) 0xc0, (byte) 0x15, (byte) 0xa1, (byte) 0xda, (byte) 0x4f,
+                                    (byte) 0xa7, (byte) 0x87, (byte) 0x37, (byte) 0xa0, (byte) 0x80,
+                                    (byte) 0xeb, (byte) 0x0a, (byte) 0x6f, (byte) 0x4f, (byte) 0x5f,
+                                    (byte) 0x8f, (byte) 0x58};
+
+    byte[] receiverChain         = {(byte) 0xd2, (byte) 0x2f, (byte) 0xd5, (byte) 0x6d, (byte) 0x3f,
+                                    (byte) 0xec, (byte) 0x81, (byte) 0x9c, (byte) 0xf4, (byte) 0xc3,
+                                    (byte) 0xd5, (byte) 0x0c, (byte) 0x56, (byte) 0xed, (byte) 0xfb,
+                                    (byte) 0x1c, (byte) 0x28, (byte) 0x0a, (byte) 0x1b, (byte) 0x31,
+                                    (byte) 0x96, (byte) 0x45, (byte) 0x37, (byte) 0xf1, (byte) 0xd1,
+                                    (byte) 0x61, (byte) 0xe1, (byte) 0xc9, (byte) 0x31, (byte) 0x48,
+                                    (byte) 0xe3, (byte) 0x6b};
+
+    IdentityKey     bobIdentityKey           = new IdentityKey(bobIdentityPublic, 0);
+    ECPublicKey     bobEphemeralPublicKey    = Curve.decodePoint(bobPublic, 0);
+    ECPublicKey     bobBasePublicKey         = bobEphemeralPublicKey;
+    ECPublicKey     aliceBasePublicKey       = Curve.decodePoint(aliceBasePublic, 0);
+    ECPrivateKey    aliceBasePrivateKey      = Curve.decodePrivatePoint(aliceBasePrivate);
+    ECKeyPair       aliceBaseKey             = new ECKeyPair(aliceBasePublicKey, aliceBasePrivateKey);
+    ECPublicKey     aliceEphemeralPublicKey  = Curve.decodePoint(aliceEphemeralPublic, 0);
+    ECPrivateKey    aliceEphemeralPrivateKey = Curve.decodePrivatePoint(aliceEphemeralPrivate);
+    ECKeyPair       aliceEphemeralKey        = new ECKeyPair(aliceEphemeralPublicKey, aliceEphemeralPrivateKey);
+    IdentityKey     aliceIdentityPublicKey   = new IdentityKey(aliceIdentityPublic, 0);
+    ECPrivateKey    aliceIdentityPrivateKey  = Curve.decodePrivatePoint(aliceIdentityPrivate);
+    IdentityKeyPair aliceIdentityKey         = new IdentityKeyPair(aliceIdentityPublicKey, aliceIdentityPrivateKey);
+
+    SessionState session = new SessionState();
+
+    AliceAxolotlParameters parameters = AliceAxolotlParameters.newBuilder()
+        .setOurBaseKey(aliceBaseKey)
+        .setOurIdentityKey(aliceIdentityKey)
+        .setTheirIdentityKey(bobIdentityKey)
+        .setTheirSignedPreKey(bobBasePublicKey)
+        .setTheirRatchetKey(bobEphemeralPublicKey)
+        .setTheirOneTimePreKey(Optional.<ECPublicKey>absent())
+        .create();
+
+    RatchetingSession.initializeSession(session, 2, parameters);
+
+    assertTrue(session.getLocalIdentityKey().equals(aliceIdentityKey.getPublicKey()));
+    assertTrue(session.getRemoteIdentityKey().equals(bobIdentityKey));
+    assertTrue(Arrays.equals(session.getReceiverChainKey(bobEphemeralPublicKey).getKey(),
+                             receiverChain));
+
+  }
+}
diff --git a/src/androidTest/java/org/whispersystems/test/ratchet/RootKeyTest.java b/src/androidTest/java/org/whispersystems/test/ratchet/RootKeyTest.java
new file mode 100644
index 00000000..c48ef23d
--- /dev/null
+++ b/src/androidTest/java/org/whispersystems/test/ratchet/RootKeyTest.java
@@ -0,0 +1,84 @@
+package org.whispersystems.test.ratchet;
+
+import android.test.AndroidTestCase;
+
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPrivateKey;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.kdf.HKDF;
+import org.whispersystems.libaxolotl.ratchet.ChainKey;
+import org.whispersystems.libaxolotl.ratchet.RootKey;
+import org.whispersystems.libaxolotl.util.Pair;
+
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+
+public class RootKeyTest extends AndroidTestCase {
+
+  public void testRootKeyDerivationV2() throws NoSuchAlgorithmException, InvalidKeyException {
+    byte[] rootKeySeed  = {(byte) 0x7b, (byte) 0xa6, (byte) 0xde, (byte) 0xbc, (byte) 0x2b,
+                           (byte) 0xc1, (byte) 0xbb, (byte) 0xf9, (byte) 0x1a, (byte) 0xbb,
+                           (byte) 0xc1, (byte) 0x36, (byte) 0x74, (byte) 0x04, (byte) 0x17,
+                           (byte) 0x6c, (byte) 0xa6, (byte) 0x23, (byte) 0x09, (byte) 0x5b,
+                           (byte) 0x7e, (byte) 0xc6, (byte) 0x6b, (byte) 0x45, (byte) 0xf6,
+                           (byte) 0x02, (byte) 0xd9, (byte) 0x35, (byte) 0x38, (byte) 0x94,
+                           (byte) 0x2d, (byte) 0xcc};
+
+    byte[] alicePublic  = {(byte) 0x05, (byte) 0xee, (byte) 0x4f, (byte) 0xa6, (byte) 0xcd,
+                           (byte) 0xc0, (byte) 0x30, (byte) 0xdf, (byte) 0x49, (byte) 0xec,
+                           (byte) 0xd0, (byte) 0xba, (byte) 0x6c, (byte) 0xfc, (byte) 0xff,
+                           (byte) 0xb2, (byte) 0x33, (byte) 0xd3, (byte) 0x65, (byte) 0xa2,
+                           (byte) 0x7f, (byte) 0xad, (byte) 0xbe, (byte) 0xff, (byte) 0x77,
+                           (byte) 0xe9, (byte) 0x63, (byte) 0xfc, (byte) 0xb1, (byte) 0x62,
+                           (byte) 0x22, (byte) 0xe1, (byte) 0x3a};
+
+    byte[] alicePrivate = {(byte) 0x21, (byte) 0x68, (byte) 0x22, (byte) 0xec, (byte) 0x67,
+                           (byte) 0xeb, (byte) 0x38, (byte) 0x04, (byte) 0x9e, (byte) 0xba,
+                           (byte) 0xe7, (byte) 0xb9, (byte) 0x39, (byte) 0xba, (byte) 0xea,
+                           (byte) 0xeb, (byte) 0xb1, (byte) 0x51, (byte) 0xbb, (byte) 0xb3,
+                           (byte) 0x2d, (byte) 0xb8, (byte) 0x0f, (byte) 0xd3, (byte) 0x89,
+                           (byte) 0x24, (byte) 0x5a, (byte) 0xc3, (byte) 0x7a, (byte) 0x94,
+                           (byte) 0x8e, (byte) 0x50};
+
+    byte[] bobPublic    = {(byte) 0x05, (byte) 0xab, (byte) 0xb8, (byte) 0xeb, (byte) 0x29,
+                           (byte) 0xcc, (byte) 0x80, (byte) 0xb4, (byte) 0x71, (byte) 0x09,
+                           (byte) 0xa2, (byte) 0x26, (byte) 0x5a, (byte) 0xbe, (byte) 0x97,
+                           (byte) 0x98, (byte) 0x48, (byte) 0x54, (byte) 0x06, (byte) 0xe3,
+                           (byte) 0x2d, (byte) 0xa2, (byte) 0x68, (byte) 0x93, (byte) 0x4a,
+                           (byte) 0x95, (byte) 0x55, (byte) 0xe8, (byte) 0x47, (byte) 0x57,
+                           (byte) 0x70, (byte) 0x8a, (byte) 0x30};
+
+    byte[] nextRoot     = {(byte) 0xb1, (byte) 0x14, (byte) 0xf5, (byte) 0xde, (byte) 0x28,
+                           (byte) 0x01, (byte) 0x19, (byte) 0x85, (byte) 0xe6, (byte) 0xeb,
+                           (byte) 0xa2, (byte) 0x5d, (byte) 0x50, (byte) 0xe7, (byte) 0xec,
+                           (byte) 0x41, (byte) 0xa9, (byte) 0xb0, (byte) 0x2f, (byte) 0x56,
+                           (byte) 0x93, (byte) 0xc5, (byte) 0xc7, (byte) 0x88, (byte) 0xa6,
+                           (byte) 0x3a, (byte) 0x06, (byte) 0xd2, (byte) 0x12, (byte) 0xa2,
+                           (byte) 0xf7, (byte) 0x31};
+
+    byte[] nextChain    = {(byte) 0x9d, (byte) 0x7d, (byte) 0x24, (byte) 0x69, (byte) 0xbc,
+                           (byte) 0x9a, (byte) 0xe5, (byte) 0x3e, (byte) 0xe9, (byte) 0x80,
+                           (byte) 0x5a, (byte) 0xa3, (byte) 0x26, (byte) 0x4d, (byte) 0x24,
+                           (byte) 0x99, (byte) 0xa3, (byte) 0xac, (byte) 0xe8, (byte) 0x0f,
+                           (byte) 0x4c, (byte) 0xca, (byte) 0xe2, (byte) 0xda, (byte) 0x13,
+                           (byte) 0x43, (byte) 0x0c, (byte) 0x5c, (byte) 0x55, (byte) 0xb5,
+                           (byte) 0xca, (byte) 0x5f};
+
+    ECPublicKey  alicePublicKey  = Curve.decodePoint(alicePublic, 0);
+    ECPrivateKey alicePrivateKey = Curve.decodePrivatePoint(alicePrivate);
+    ECKeyPair    aliceKeyPair    = new ECKeyPair(alicePublicKey, alicePrivateKey);
+
+    ECPublicKey bobPublicKey = Curve.decodePoint(bobPublic, 0);
+    RootKey     rootKey      = new RootKey(HKDF.createFor(2), rootKeySeed);
+
+    Pair<RootKey, ChainKey> rootKeyChainKeyPair = rootKey.createChain(bobPublicKey, aliceKeyPair);
+    RootKey                 nextRootKey         = rootKeyChainKeyPair.first();
+    ChainKey                nextChainKey        = rootKeyChainKeyPair.second();
+
+    assertTrue(Arrays.equals(rootKey.getKeyBytes(), rootKeySeed));
+    assertTrue(Arrays.equals(nextRootKey.getKeyBytes(), nextRoot));
+    assertTrue(Arrays.equals(nextChainKey.getKey(), nextChain));
+  }
+}
diff --git a/src/main/AndroidManifest.xml b/src/main/AndroidManifest.xml
new file mode 100644
index 00000000..28d28168
--- /dev/null
+++ b/src/main/AndroidManifest.xml
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+          package="org.whispersystems.libaxolotl"
+          android:versionCode="1"
+          android:versionName="0.1">
+    <application />
+</manifest>
diff --git a/src/main/java/org/whispersystems/libaxolotl/DuplicateMessageException.java b/src/main/java/org/whispersystems/libaxolotl/DuplicateMessageException.java
new file mode 100644
index 00000000..913c0121
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/DuplicateMessageException.java
@@ -0,0 +1,7 @@
+package org.whispersystems.libaxolotl;
+
+public class DuplicateMessageException extends Exception {
+  public DuplicateMessageException(String s) {
+    super(s);
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/IdentityKey.java b/src/main/java/org/whispersystems/libaxolotl/IdentityKey.java
new file mode 100644
index 00000000..35af3394
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/IdentityKey.java
@@ -0,0 +1,66 @@
+/** 
+ * Copyright (C) 2014 Open Whisper Systems
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl;
+
+
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.util.Hex;
+
+/**
+ * A class for representing an identity key.
+ * 
+ * @author Moxie Marlinspike
+ */
+
+public class IdentityKey {
+
+  private final ECPublicKey publicKey;
+
+  public IdentityKey(ECPublicKey publicKey) {
+    this.publicKey = publicKey;
+  }
+
+  public IdentityKey(byte[] bytes, int offset) throws InvalidKeyException {
+    this.publicKey = Curve.decodePoint(bytes, offset);
+  }
+
+  public ECPublicKey getPublicKey() {
+    return publicKey;
+  }
+
+  public byte[] serialize() {
+    return publicKey.serialize();
+  }
+
+  public String getFingerprint() {
+    return Hex.toString(publicKey.serialize());
+  }
+	
+  @Override
+  public boolean equals(Object other) {
+    if (other == null)                   return false;
+    if (!(other instanceof IdentityKey)) return false;
+
+    return publicKey.equals(((IdentityKey) other).getPublicKey());
+  }
+	
+  @Override
+  public int hashCode() {
+    return publicKey.hashCode();
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/IdentityKeyPair.java b/src/main/java/org/whispersystems/libaxolotl/IdentityKeyPair.java
new file mode 100644
index 00000000..c47df4bc
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/IdentityKeyPair.java
@@ -0,0 +1,66 @@
+/**
+ * Copyright (C) 2013 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECPrivateKey;
+
+import static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure;
+
+/**
+ * Holder for public and private identity key pair.
+ *
+ * @author Moxie Marlinspike
+ */
+public class IdentityKeyPair {
+
+  private final IdentityKey  publicKey;
+  private final ECPrivateKey privateKey;
+
+  public IdentityKeyPair(IdentityKey publicKey, ECPrivateKey privateKey) {
+    this.publicKey  = publicKey;
+    this.privateKey = privateKey;
+  }
+
+  public IdentityKeyPair(byte[] serialized) throws InvalidKeyException {
+    try {
+      IdentityKeyPairStructure structure = IdentityKeyPairStructure.parseFrom(serialized);
+      this.publicKey  = new IdentityKey(structure.getPublicKey().toByteArray(), 0);
+      this.privateKey = Curve.decodePrivatePoint(structure.getPrivateKey().toByteArray());
+    } catch (InvalidProtocolBufferException e) {
+      throw new InvalidKeyException(e);
+    }
+  }
+
+  public IdentityKey getPublicKey() {
+    return publicKey;
+  }
+
+  public ECPrivateKey getPrivateKey() {
+    return privateKey;
+  }
+
+  public byte[] serialize() {
+    return IdentityKeyPairStructure.newBuilder()
+                                   .setPublicKey(ByteString.copyFrom(publicKey.serialize()))
+                                   .setPrivateKey(ByteString.copyFrom(privateKey.serialize()))
+                                   .build().toByteArray();
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/InvalidKeyException.java b/src/main/java/org/whispersystems/libaxolotl/InvalidKeyException.java
new file mode 100644
index 00000000..bb70df16
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/InvalidKeyException.java
@@ -0,0 +1,34 @@
+/** 
+ * Copyright (C) 2014 Open Whisper Systems
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl;
+
+public class InvalidKeyException extends Exception {
+
+  public InvalidKeyException() {}
+
+  public InvalidKeyException(String detailMessage) {
+    super(detailMessage);
+  }
+
+  public InvalidKeyException(Throwable throwable) {
+    super(throwable);
+  }
+
+  public InvalidKeyException(String detailMessage, Throwable throwable) {
+    super(detailMessage, throwable);
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/InvalidKeyIdException.java b/src/main/java/org/whispersystems/libaxolotl/InvalidKeyIdException.java
new file mode 100644
index 00000000..c7c6bc01
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/InvalidKeyIdException.java
@@ -0,0 +1,27 @@
+/** 
+ * Copyright (C) 2014 Open Whisper Systems
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl;
+
+public class InvalidKeyIdException extends Exception {
+  public InvalidKeyIdException(String detailMessage) {
+    super(detailMessage);
+  }
+
+  public InvalidKeyIdException(Throwable throwable) {
+    super(throwable);
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/InvalidMacException.java b/src/main/java/org/whispersystems/libaxolotl/InvalidMacException.java
new file mode 100644
index 00000000..0afc6996
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/InvalidMacException.java
@@ -0,0 +1,28 @@
+/** 
+ * Copyright (C) 2014 Open Whisper Systems
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl;
+
+public class InvalidMacException extends Exception {
+
+  public InvalidMacException(String detailMessage) {
+    super(detailMessage);
+  }
+
+  public InvalidMacException(Throwable throwable) {
+    super(throwable);
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/InvalidMessageException.java b/src/main/java/org/whispersystems/libaxolotl/InvalidMessageException.java
new file mode 100644
index 00000000..063eb594
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/InvalidMessageException.java
@@ -0,0 +1,40 @@
+/** 
+ * Copyright (C) 2014 Open Whisper Systems
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl;
+
+import java.util.List;
+
+public class InvalidMessageException extends Exception {
+
+  public InvalidMessageException() {}
+
+  public InvalidMessageException(String detailMessage) {
+    super(detailMessage);
+  }
+
+  public InvalidMessageException(Throwable throwable) {
+    super(throwable);
+  }
+
+  public InvalidMessageException(String detailMessage, Throwable throwable) {
+    super(detailMessage, throwable);
+  }
+
+  public InvalidMessageException(String detailMessage, List<Exception> exceptions) {
+    super(detailMessage, exceptions.get(0));
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/InvalidVersionException.java b/src/main/java/org/whispersystems/libaxolotl/InvalidVersionException.java
new file mode 100644
index 00000000..a1324443
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/InvalidVersionException.java
@@ -0,0 +1,23 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl;
+
+public class InvalidVersionException extends Exception {
+  public InvalidVersionException(String detailMessage) {
+    super(detailMessage);
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/LegacyMessageException.java b/src/main/java/org/whispersystems/libaxolotl/LegacyMessageException.java
new file mode 100644
index 00000000..dadde754
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/LegacyMessageException.java
@@ -0,0 +1,7 @@
+package org.whispersystems.libaxolotl;
+
+public class LegacyMessageException extends Exception {
+  public LegacyMessageException(String s) {
+    super(s);
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/NoSessionException.java b/src/main/java/org/whispersystems/libaxolotl/NoSessionException.java
new file mode 100644
index 00000000..16203554
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/NoSessionException.java
@@ -0,0 +1,11 @@
+package org.whispersystems.libaxolotl;
+
+public class NoSessionException extends Exception {
+  public NoSessionException(String s) {
+    super(s);
+  }
+
+  public NoSessionException(Exception nested) {
+    super(nested);
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/SessionBuilder.java b/src/main/java/org/whispersystems/libaxolotl/SessionBuilder.java
new file mode 100644
index 00000000..2d1c8969
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/SessionBuilder.java
@@ -0,0 +1,411 @@
+package org.whispersystems.libaxolotl;
+
+import android.util.Log;
+
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.protocol.CiphertextMessage;
+import org.whispersystems.libaxolotl.protocol.KeyExchangeMessage;
+import org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage;
+import org.whispersystems.libaxolotl.ratchet.AliceAxolotlParameters;
+import org.whispersystems.libaxolotl.ratchet.BobAxolotlParameters;
+import org.whispersystems.libaxolotl.ratchet.RatchetingSession;
+import org.whispersystems.libaxolotl.ratchet.SymmetricAxolotlParameters;
+import org.whispersystems.libaxolotl.state.AxolotlStore;
+import org.whispersystems.libaxolotl.state.IdentityKeyStore;
+import org.whispersystems.libaxolotl.state.PreKeyBundle;
+import org.whispersystems.libaxolotl.state.PreKeyStore;
+import org.whispersystems.libaxolotl.state.SessionRecord;
+import org.whispersystems.libaxolotl.state.SessionState;
+import org.whispersystems.libaxolotl.state.SessionStore;
+import org.whispersystems.libaxolotl.state.SignedPreKeyStore;
+import org.whispersystems.libaxolotl.util.KeyHelper;
+import org.whispersystems.libaxolotl.util.Medium;
+import org.whispersystems.libaxolotl.util.guava.Optional;
+
+/**
+ * SessionBuilder is responsible for setting up encrypted sessions.
+ * Once a session has been established, {@link org.whispersystems.libaxolotl.SessionCipher}
+ * can be used to encrypt/decrypt messages in that session.
+ * <p>
+ * Sessions are built from one of three different possible vectors:
+ * <ol>
+ *   <li>A {@link org.whispersystems.libaxolotl.state.PreKeyBundle} retrieved from a server.</li>
+ *   <li>A {@link org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage} received from a client.</li>
+ *   <li>A {@link org.whispersystems.libaxolotl.protocol.KeyExchangeMessage} sent to or received from a client.</li>
+ * </ol>
+ *
+ * Sessions are constructed per recipientId + deviceId tuple.  Remote logical users are identified
+ * by their recipientId, and each logical recipientId can have multiple physical devices.
+ *
+ * @author Moxie Marlinspike
+ */
+public class SessionBuilder {
+
+  private static final String TAG = SessionBuilder.class.getSimpleName();
+
+  private final SessionStore      sessionStore;
+  private final PreKeyStore       preKeyStore;
+  private final SignedPreKeyStore signedPreKeyStore;
+  private final IdentityKeyStore  identityKeyStore;
+  private final long              recipientId;
+  private final int               deviceId;
+
+  /**
+   * Constructs a SessionBuilder.
+   *
+   * @param sessionStore The {@link org.whispersystems.libaxolotl.state.SessionStore} to store the constructed session in.
+   * @param preKeyStore The {@link  org.whispersystems.libaxolotl.state.PreKeyStore} where the client's local {@link org.whispersystems.libaxolotl.state.PreKeyRecord}s are stored.
+   * @param identityKeyStore The {@link org.whispersystems.libaxolotl.state.IdentityKeyStore} containing the client's identity key information.
+   * @param recipientId The recipient ID of the remote user to build a session with.
+   * @param deviceId The device ID of the remote user's physical device.
+   */
+  public SessionBuilder(SessionStore sessionStore,
+                        PreKeyStore preKeyStore,
+                        SignedPreKeyStore signedPreKeyStore,
+                        IdentityKeyStore identityKeyStore,
+                        long recipientId, int deviceId)
+  {
+    this.sessionStore      = sessionStore;
+    this.preKeyStore       = preKeyStore;
+    this.signedPreKeyStore = signedPreKeyStore;
+    this.identityKeyStore  = identityKeyStore;
+    this.recipientId       = recipientId;
+    this.deviceId          = deviceId;
+  }
+
+  /**
+   * Constructs a SessionBuilder
+   * @param store The {@link org.whispersystems.libaxolotl.state.AxolotlStore} to store all state information in.
+   * @param recipientId The recipient ID of the remote user to build a session with.
+   * @param deviceId The device ID of the remote user's physical device.
+   */
+  public SessionBuilder(AxolotlStore store, long recipientId, int deviceId) {
+    this(store, store, store, store, recipientId, deviceId);
+  }
+
+  /**
+   * Build a new session from a received {@link org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage}.
+   *
+   * After a session is constructed in this way, the embedded {@link org.whispersystems.libaxolotl.protocol.WhisperMessage}
+   * can be decrypted.
+   *
+   * @param message The received {@link org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage}.
+   * @throws org.whispersystems.libaxolotl.InvalidKeyIdException when there is no local
+   *                                                             {@link org.whispersystems.libaxolotl.state.PreKeyRecord}
+   *                                                             that corresponds to the PreKey ID in
+   *                                                             the message.
+   * @throws org.whispersystems.libaxolotl.InvalidKeyException when the message is formatted incorrectly.
+   * @throws org.whispersystems.libaxolotl.UntrustedIdentityException when the {@link IdentityKey} of the sender is untrusted.
+   */
+  /*package*/ Optional<Integer> process(SessionRecord sessionRecord, PreKeyWhisperMessage message)
+      throws InvalidKeyIdException, InvalidKeyException, UntrustedIdentityException
+  {
+    int         messageVersion   = message.getMessageVersion();
+    IdentityKey theirIdentityKey = message.getIdentityKey();
+
+    Optional<Integer> unsignedPreKeyId;
+
+    if (!identityKeyStore.isTrustedIdentity(recipientId, theirIdentityKey)) {
+      throw new UntrustedIdentityException();
+    }
+
+    switch (messageVersion) {
+      case 2:  unsignedPreKeyId = processV2(sessionRecord, message); break;
+      case 3:  unsignedPreKeyId = processV3(sessionRecord, message); break;
+      default: throw new AssertionError("Unknown version: " + messageVersion);
+    }
+
+    identityKeyStore.saveIdentity(recipientId, theirIdentityKey);
+    return unsignedPreKeyId;
+  }
+
+  private Optional<Integer> processV3(SessionRecord sessionRecord, PreKeyWhisperMessage message)
+      throws UntrustedIdentityException, InvalidKeyIdException, InvalidKeyException
+  {
+
+    if (sessionRecord.hasSessionState(message.getMessageVersion(), message.getBaseKey().serialize())) {
+      Log.w(TAG, "We've already setup a session for this V3 message, letting bundled message fall through...");
+      return Optional.absent();
+    }
+
+    ECKeyPair ourSignedPreKey = signedPreKeyStore.loadSignedPreKey(message.getSignedPreKeyId()).getKeyPair();
+
+    BobAxolotlParameters.Builder parameters = BobAxolotlParameters.newBuilder();
+
+    parameters.setTheirBaseKey(message.getBaseKey())
+              .setTheirIdentityKey(message.getIdentityKey())
+              .setOurIdentityKey(identityKeyStore.getIdentityKeyPair())
+              .setOurSignedPreKey(ourSignedPreKey)
+              .setOurRatchetKey(ourSignedPreKey);
+
+    if (message.getPreKeyId().isPresent()) {
+      parameters.setOurOneTimePreKey(Optional.of(preKeyStore.loadPreKey(message.getPreKeyId().get()).getKeyPair()));
+    } else {
+      parameters.setOurOneTimePreKey(Optional.<ECKeyPair>absent());
+    }
+
+    if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
+
+    RatchetingSession.initializeSession(sessionRecord.getSessionState(), message.getMessageVersion(), parameters.create());
+
+    sessionRecord.getSessionState().setLocalRegistrationId(identityKeyStore.getLocalRegistrationId());
+    sessionRecord.getSessionState().setRemoteRegistrationId(message.getRegistrationId());
+    sessionRecord.getSessionState().setAliceBaseKey(message.getBaseKey().serialize());
+
+    if (message.getPreKeyId().isPresent() && message.getPreKeyId().get() != Medium.MAX_VALUE) {
+      return message.getPreKeyId();
+    } else {
+      return Optional.absent();
+    }
+  }
+
+  private Optional<Integer> processV2(SessionRecord sessionRecord, PreKeyWhisperMessage message)
+      throws UntrustedIdentityException, InvalidKeyIdException, InvalidKeyException
+  {
+    if (!message.getPreKeyId().isPresent()) {
+      throw new InvalidKeyIdException("V2 message requires one time prekey id!");
+    }
+
+    if (!preKeyStore.containsPreKey(message.getPreKeyId().get()) &&
+        sessionStore.containsSession(recipientId, deviceId))
+    {
+      Log.w(TAG, "We've already processed the prekey part of this V2 session, letting bundled message fall through...");
+      return Optional.absent();
+    }
+
+    ECKeyPair ourPreKey = preKeyStore.loadPreKey(message.getPreKeyId().get()).getKeyPair();
+
+    BobAxolotlParameters.Builder parameters = BobAxolotlParameters.newBuilder();
+
+    parameters.setOurIdentityKey(identityKeyStore.getIdentityKeyPair())
+              .setOurSignedPreKey(ourPreKey)
+              .setOurRatchetKey(ourPreKey)
+              .setOurOneTimePreKey(Optional.<ECKeyPair>absent())
+              .setTheirIdentityKey(message.getIdentityKey())
+              .setTheirBaseKey(message.getBaseKey());
+
+    if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
+
+    RatchetingSession.initializeSession(sessionRecord.getSessionState(), message.getMessageVersion(), parameters.create());
+
+    sessionRecord.getSessionState().setLocalRegistrationId(identityKeyStore.getLocalRegistrationId());
+    sessionRecord.getSessionState().setRemoteRegistrationId(message.getRegistrationId());
+    sessionRecord.getSessionState().setAliceBaseKey(message.getBaseKey().serialize());
+
+    if (message.getPreKeyId().get() != Medium.MAX_VALUE) {
+      return message.getPreKeyId();
+    } else {
+      return Optional.absent();
+    }
+  }
+
+  /**
+   * Build a new session from a {@link org.whispersystems.libaxolotl.state.PreKeyBundle} retrieved from
+   * a server.
+   *
+   * @param preKey A PreKey for the destination recipient, retrieved from a server.
+   * @throws InvalidKeyException when the {@link org.whispersystems.libaxolotl.state.PreKeyBundle} is
+   *                             badly formatted.
+   * @throws org.whispersystems.libaxolotl.UntrustedIdentityException when the sender's
+   *                                                                  {@link IdentityKey} is not
+   *                                                                  trusted.
+   */
+  public void process(PreKeyBundle preKey) throws InvalidKeyException, UntrustedIdentityException {
+    synchronized (SessionCipher.SESSION_LOCK) {
+      if (!identityKeyStore.isTrustedIdentity(recipientId, preKey.getIdentityKey())) {
+        throw new UntrustedIdentityException();
+      }
+
+      if (preKey.getSignedPreKey() != null &&
+          !Curve.verifySignature(preKey.getIdentityKey().getPublicKey(),
+                                 preKey.getSignedPreKey().serialize(),
+                                 preKey.getSignedPreKeySignature()))
+      {
+        throw new InvalidKeyException("Invalid signature on device key!");
+      }
+
+      if (preKey.getSignedPreKey() == null && preKey.getPreKey() == null) {
+        throw new InvalidKeyException("Both signed and unsigned prekeys are absent!");
+      }
+
+      boolean               supportsV3           = preKey.getSignedPreKey() != null;
+      SessionRecord         sessionRecord        = sessionStore.loadSession(recipientId, deviceId);
+      ECKeyPair             ourBaseKey           = Curve.generateKeyPair();
+      ECPublicKey           theirSignedPreKey    = supportsV3 ? preKey.getSignedPreKey() : preKey.getPreKey();
+      Optional<ECPublicKey> theirOneTimePreKey   = Optional.fromNullable(preKey.getPreKey());
+      Optional<Integer>     theirOneTimePreKeyId = theirOneTimePreKey.isPresent() ? Optional.of(preKey.getPreKeyId()) :
+                                                                                    Optional.<Integer>absent();
+
+      AliceAxolotlParameters.Builder parameters = AliceAxolotlParameters.newBuilder();
+
+      parameters.setOurBaseKey(ourBaseKey)
+                .setOurIdentityKey(identityKeyStore.getIdentityKeyPair())
+                .setTheirIdentityKey(preKey.getIdentityKey())
+                .setTheirSignedPreKey(theirSignedPreKey)
+                .setTheirRatchetKey(theirSignedPreKey)
+                .setTheirOneTimePreKey(supportsV3 ? theirOneTimePreKey : Optional.<ECPublicKey>absent());
+
+      if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
+
+      RatchetingSession.initializeSession(sessionRecord.getSessionState(),
+                                          supportsV3 ? 3 : 2,
+                                          parameters.create());
+
+      sessionRecord.getSessionState().setUnacknowledgedPreKeyMessage(theirOneTimePreKeyId, preKey.getSignedPreKeyId(), ourBaseKey.getPublicKey());
+      sessionRecord.getSessionState().setLocalRegistrationId(identityKeyStore.getLocalRegistrationId());
+      sessionRecord.getSessionState().setRemoteRegistrationId(preKey.getRegistrationId());
+      sessionRecord.getSessionState().setAliceBaseKey(ourBaseKey.getPublicKey().serialize());
+
+      sessionStore.storeSession(recipientId, deviceId, sessionRecord);
+      identityKeyStore.saveIdentity(recipientId, preKey.getIdentityKey());
+    }
+  }
+
+  /**
+   * Build a new session from a {@link org.whispersystems.libaxolotl.protocol.KeyExchangeMessage}
+   * received from a remote client.
+   *
+   * @param message The received KeyExchangeMessage.
+   * @return The KeyExchangeMessage to respond with, or null if no response is necessary.
+   * @throws InvalidKeyException if the received KeyExchangeMessage is badly formatted.
+   */
+  public KeyExchangeMessage process(KeyExchangeMessage message)
+      throws InvalidKeyException, UntrustedIdentityException, StaleKeyExchangeException
+  {
+    synchronized (SessionCipher.SESSION_LOCK) {
+      if (!identityKeyStore.isTrustedIdentity(recipientId, message.getIdentityKey())) {
+        throw new UntrustedIdentityException();
+      }
+
+      KeyExchangeMessage responseMessage = null;
+
+      if (message.isInitiate()) responseMessage = processInitiate(message);
+      else                      processResponse(message);
+
+      return responseMessage;
+    }
+  }
+
+  private KeyExchangeMessage processInitiate(KeyExchangeMessage message) throws InvalidKeyException {
+    int           flags         = KeyExchangeMessage.RESPONSE_FLAG;
+    SessionRecord sessionRecord = sessionStore.loadSession(recipientId, deviceId);
+
+    if (message.getVersion() >= 3 &&
+        !Curve.verifySignature(message.getIdentityKey().getPublicKey(),
+                               message.getBaseKey().serialize(),
+                               message.getBaseKeySignature()))
+    {
+      throw new InvalidKeyException("Bad signature!");
+    }
+
+    SymmetricAxolotlParameters.Builder builder = SymmetricAxolotlParameters.newBuilder();
+
+    if (!sessionRecord.getSessionState().hasPendingKeyExchange()) {
+      builder.setOurIdentityKey(identityKeyStore.getIdentityKeyPair())
+             .setOurBaseKey(Curve.generateKeyPair())
+             .setOurRatchetKey(Curve.generateKeyPair());
+    } else {
+      builder.setOurIdentityKey(sessionRecord.getSessionState().getPendingKeyExchangeIdentityKey())
+             .setOurBaseKey(sessionRecord.getSessionState().getPendingKeyExchangeBaseKey())
+             .setOurRatchetKey(sessionRecord.getSessionState().getPendingKeyExchangeRatchetKey());
+      flags |= KeyExchangeMessage.SIMULTAENOUS_INITIATE_FLAG;
+    }
+
+    builder.setTheirBaseKey(message.getBaseKey())
+           .setTheirRatchetKey(message.getRatchetKey())
+           .setTheirIdentityKey(message.getIdentityKey());
+
+    SymmetricAxolotlParameters parameters = builder.create();
+
+    if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
+
+    RatchetingSession.initializeSession(sessionRecord.getSessionState(),
+                                        Math.min(message.getMaxVersion(), CiphertextMessage.CURRENT_VERSION),
+                                        parameters);
+
+    sessionStore.storeSession(recipientId, deviceId, sessionRecord);
+    identityKeyStore.saveIdentity(recipientId, message.getIdentityKey());
+
+    byte[] baseKeySignature = Curve.calculateSignature(parameters.getOurIdentityKey().getPrivateKey(),
+                                                       parameters.getOurBaseKey().getPublicKey().serialize());
+
+    return new KeyExchangeMessage(sessionRecord.getSessionState().getSessionVersion(),
+                                  message.getSequence(), flags,
+                                  parameters.getOurBaseKey().getPublicKey(),
+                                  baseKeySignature, parameters.getOurRatchetKey().getPublicKey(),
+                                  parameters.getOurIdentityKey().getPublicKey());
+  }
+
+  private void processResponse(KeyExchangeMessage message)
+      throws StaleKeyExchangeException, InvalidKeyException
+  {
+    SessionRecord sessionRecord                  = sessionStore.loadSession(recipientId, deviceId);
+    SessionState  sessionState                   = sessionRecord.getSessionState();
+    boolean       hasPendingKeyExchange          = sessionState.hasPendingKeyExchange();
+    boolean       isSimultaneousInitiateResponse = message.isResponseForSimultaneousInitiate();
+
+    if (!hasPendingKeyExchange || sessionState.getPendingKeyExchangeSequence() != message.getSequence()) {
+      Log.w(TAG, "No matching sequence for response. Is simultaneous initiate response: " + isSimultaneousInitiateResponse);
+      if (!isSimultaneousInitiateResponse) throw new StaleKeyExchangeException();
+      else                                 return;
+    }
+
+    SymmetricAxolotlParameters.Builder parameters = SymmetricAxolotlParameters.newBuilder();
+
+    parameters.setOurBaseKey(sessionRecord.getSessionState().getPendingKeyExchangeBaseKey())
+              .setOurRatchetKey(sessionRecord.getSessionState().getPendingKeyExchangeRatchetKey())
+              .setOurIdentityKey(sessionRecord.getSessionState().getPendingKeyExchangeIdentityKey())
+              .setTheirBaseKey(message.getBaseKey())
+              .setTheirRatchetKey(message.getRatchetKey())
+              .setTheirIdentityKey(message.getIdentityKey());
+
+    if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
+
+    RatchetingSession.initializeSession(sessionRecord.getSessionState(),
+                                        Math.min(message.getMaxVersion(), CiphertextMessage.CURRENT_VERSION),
+                                        parameters.create());
+
+    if (sessionRecord.getSessionState().getSessionVersion() >= 3 &&
+        !Curve.verifySignature(message.getIdentityKey().getPublicKey(),
+                               message.getBaseKey().serialize(),
+                               message.getBaseKeySignature()))
+    {
+      throw new InvalidKeyException("Base key signature doesn't match!");
+    }
+
+    sessionStore.storeSession(recipientId, deviceId, sessionRecord);
+    identityKeyStore.saveIdentity(recipientId, message.getIdentityKey());
+
+  }
+
+  /**
+   * Initiate a new session by sending an initial KeyExchangeMessage to the recipient.
+   *
+   * @return the KeyExchangeMessage to deliver.
+   */
+  public KeyExchangeMessage process() {
+    synchronized (SessionCipher.SESSION_LOCK) {
+      try {
+        int             sequence         = KeyHelper.getRandomSequence(65534) + 1;
+        int             flags            = KeyExchangeMessage.INITIATE_FLAG;
+        ECKeyPair       baseKey          = Curve.generateKeyPair();
+        ECKeyPair       ratchetKey       = Curve.generateKeyPair();
+        IdentityKeyPair identityKey      = identityKeyStore.getIdentityKeyPair();
+        byte[]          baseKeySignature = Curve.calculateSignature(identityKey.getPrivateKey(), baseKey.getPublicKey().serialize());
+        SessionRecord   sessionRecord    = sessionStore.loadSession(recipientId, deviceId);
+
+        sessionRecord.getSessionState().setPendingKeyExchange(sequence, baseKey, ratchetKey, identityKey);
+        sessionStore.storeSession(recipientId, deviceId, sessionRecord);
+
+        return new KeyExchangeMessage(2, sequence, flags, baseKey.getPublicKey(), baseKeySignature,
+                                      ratchetKey.getPublicKey(), identityKey.getPublicKey());
+      } catch (InvalidKeyException e) {
+        throw new AssertionError(e);
+      }
+    }
+  }
+
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/SessionCipher.java b/src/main/java/org/whispersystems/libaxolotl/SessionCipher.java
new file mode 100644
index 00000000..381dedb8
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/SessionCipher.java
@@ -0,0 +1,469 @@
+/** 
+ * Copyright (C) 2013 Open Whisper Systems
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl;
+
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.protocol.CiphertextMessage;
+import org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage;
+import org.whispersystems.libaxolotl.protocol.WhisperMessage;
+import org.whispersystems.libaxolotl.ratchet.ChainKey;
+import org.whispersystems.libaxolotl.ratchet.MessageKeys;
+import org.whispersystems.libaxolotl.ratchet.RootKey;
+import org.whispersystems.libaxolotl.state.AxolotlStore;
+import org.whispersystems.libaxolotl.state.IdentityKeyStore;
+import org.whispersystems.libaxolotl.state.PreKeyStore;
+import org.whispersystems.libaxolotl.state.SessionRecord;
+import org.whispersystems.libaxolotl.state.SessionState;
+import org.whispersystems.libaxolotl.state.SessionStore;
+import org.whispersystems.libaxolotl.state.SignedPreKeyStore;
+import org.whispersystems.libaxolotl.util.ByteUtil;
+import org.whispersystems.libaxolotl.util.Pair;
+import org.whispersystems.libaxolotl.util.guava.Optional;
+
+import java.security.InvalidAlgorithmParameterException;
+import java.security.NoSuchAlgorithmException;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+import static org.whispersystems.libaxolotl.state.SessionState.UnacknowledgedPreKeyMessageItems;
+
+/**
+ * The main entry point for Axolotl encrypt/decrypt operations.
+ *
+ * Once a session has been established with {@link SessionBuilder},
+ * this class can be used for all encrypt/decrypt operations within
+ * that session.
+ *
+ * @author Moxie Marlinspike
+ */
+public class SessionCipher {
+
+  public static final Object SESSION_LOCK = new Object();
+
+  private final SessionStore   sessionStore;
+  private final SessionBuilder sessionBuilder;
+  private final PreKeyStore    preKeyStore;
+  private final long           recipientId;
+  private final int            deviceId;
+
+  /**
+   * Construct a SessionCipher for encrypt/decrypt operations on a session.
+   * In order to use SessionCipher, a session must have already been created
+   * and stored using {@link SessionBuilder}.
+   *
+   * @param  sessionStore The {@link SessionStore} that contains a session for this recipient.
+   * @param  recipientId  The remote ID that messages will be encrypted to or decrypted from.
+   * @param  deviceId     The device corresponding to the recipientId.
+   */
+  public SessionCipher(SessionStore sessionStore, PreKeyStore preKeyStore,
+                       SignedPreKeyStore signedPreKeyStore, IdentityKeyStore identityKeyStore,
+                       long recipientId, int deviceId)
+  {
+    this.sessionStore   = sessionStore;
+    this.recipientId    = recipientId;
+    this.deviceId       = deviceId;
+    this.preKeyStore    = preKeyStore;
+    this.sessionBuilder = new SessionBuilder(sessionStore, preKeyStore, signedPreKeyStore,
+                                             identityKeyStore, recipientId, deviceId);
+  }
+
+  public SessionCipher(AxolotlStore store, long recipientId, int deviceId) {
+    this(store, store, store, store, recipientId, deviceId);
+  }
+
+  /**
+   * Encrypt a message.
+   *
+   * @param  paddedMessage The plaintext message bytes, optionally padded to a constant multiple.
+   * @return A ciphertext message encrypted to the recipient+device tuple.
+   */
+  public CiphertextMessage encrypt(byte[] paddedMessage) {
+    synchronized (SESSION_LOCK) {
+      SessionRecord sessionRecord   = sessionStore.loadSession(recipientId, deviceId);
+      SessionState  sessionState    = sessionRecord.getSessionState();
+      ChainKey      chainKey        = sessionState.getSenderChainKey();
+      MessageKeys   messageKeys     = chainKey.getMessageKeys();
+      ECPublicKey   senderEphemeral = sessionState.getSenderRatchetKey();
+      int           previousCounter = sessionState.getPreviousCounter();
+      int           sessionVersion  = sessionState.getSessionVersion();
+
+      byte[]            ciphertextBody    = getCiphertext(sessionVersion, messageKeys, paddedMessage);
+      CiphertextMessage ciphertextMessage = new WhisperMessage(sessionVersion, messageKeys.getMacKey(),
+                                                               senderEphemeral, chainKey.getIndex(),
+                                                               previousCounter, ciphertextBody,
+                                                               sessionState.getLocalIdentityKey(),
+                                                               sessionState.getRemoteIdentityKey());
+
+      if (sessionState.hasUnacknowledgedPreKeyMessage()) {
+        UnacknowledgedPreKeyMessageItems items = sessionState.getUnacknowledgedPreKeyMessageItems();
+        int localRegistrationId = sessionState.getLocalRegistrationId();
+
+        ciphertextMessage = new PreKeyWhisperMessage(sessionVersion, localRegistrationId, items.getPreKeyId(),
+                                                     items.getSignedPreKeyId(), items.getBaseKey(),
+                                                     sessionState.getLocalIdentityKey(),
+                                                     (WhisperMessage) ciphertextMessage);
+      }
+
+      sessionState.setSenderChainKey(chainKey.getNextChainKey());
+      sessionStore.storeSession(recipientId, deviceId, sessionRecord);
+      return ciphertextMessage;
+    }
+  }
+
+  /**
+   * Decrypt a message.
+   *
+   * @param  ciphertext The {@link PreKeyWhisperMessage} to decrypt.
+   *
+   * @return The plaintext.
+   * @throws InvalidMessageException if the input is not valid ciphertext.
+   * @throws DuplicateMessageException if the input is a message that has already been received.
+   * @throws LegacyMessageException if the input is a message formatted by a protocol version that
+   *                                is no longer supported.
+   * @throws InvalidKeyIdException when there is no local {@link org.whispersystems.libaxolotl.state.PreKeyRecord}
+   *                               that corresponds to the PreKey ID in the message.
+   * @throws InvalidKeyException when the message is formatted incorrectly.
+   * @throws UntrustedIdentityException when the {@link IdentityKey} of the sender is untrusted.
+   */
+  public byte[] decrypt(PreKeyWhisperMessage ciphertext)
+      throws DuplicateMessageException, LegacyMessageException, InvalidMessageException,
+             InvalidKeyIdException, InvalidKeyException, UntrustedIdentityException
+  {
+    return decrypt(ciphertext, new NullDecryptionCallback());
+  }
+
+  /**
+   * Decrypt a message.
+   *
+   * @param  ciphertext The {@link PreKeyWhisperMessage} to decrypt.
+   * @param  callback   A callback that is triggered after decryption is complete,
+   *                    but before the updated session state has been committed to the session
+   *                    DB.  This allows some implementations to store the committed plaintext
+   *                    to a DB first, in case they are concerned with a crash happening between
+   *                    the time the session state is updated but before they're able to store
+   *                    the plaintext to disk.
+   *
+   * @return The plaintext.
+   * @throws InvalidMessageException if the input is not valid ciphertext.
+   * @throws DuplicateMessageException if the input is a message that has already been received.
+   * @throws LegacyMessageException if the input is a message formatted by a protocol version that
+   *                                is no longer supported.
+   * @throws InvalidKeyIdException when there is no local {@link org.whispersystems.libaxolotl.state.PreKeyRecord}
+   *                               that corresponds to the PreKey ID in the message.
+   * @throws InvalidKeyException when the message is formatted incorrectly.
+   * @throws UntrustedIdentityException when the {@link IdentityKey} of the sender is untrusted.
+   */
+  public byte[] decrypt(PreKeyWhisperMessage ciphertext, DecryptionCallback callback)
+      throws DuplicateMessageException, LegacyMessageException, InvalidMessageException,
+             InvalidKeyIdException, InvalidKeyException, UntrustedIdentityException
+  {
+    synchronized (SESSION_LOCK) {
+      SessionRecord     sessionRecord    = sessionStore.loadSession(recipientId, deviceId);
+      Optional<Integer> unsignedPreKeyId = sessionBuilder.process(sessionRecord, ciphertext);
+      byte[]            plaintext        = decrypt(sessionRecord, ciphertext.getWhisperMessage());
+
+      callback.handlePlaintext(plaintext);
+
+      sessionStore.storeSession(recipientId, deviceId, sessionRecord);
+
+      if (unsignedPreKeyId.isPresent()) {
+        preKeyStore.removePreKey(unsignedPreKeyId.get());
+      }
+
+      return plaintext;
+    }
+  }
+
+  /**
+   * Decrypt a message.
+   *
+   * @param  ciphertext The {@link WhisperMessage} to decrypt.
+   *
+   * @return The plaintext.
+   * @throws InvalidMessageException if the input is not valid ciphertext.
+   * @throws DuplicateMessageException if the input is a message that has already been received.
+   * @throws LegacyMessageException if the input is a message formatted by a protocol version that
+   *                                is no longer supported.
+   * @throws NoSessionException if there is no established session for this contact.
+   */
+  public byte[] decrypt(WhisperMessage ciphertext)
+      throws InvalidMessageException, DuplicateMessageException, LegacyMessageException,
+      NoSessionException
+  {
+    return decrypt(ciphertext, new NullDecryptionCallback());
+  }
+
+  /**
+   * Decrypt a message.
+   *
+   * @param  ciphertext The {@link WhisperMessage} to decrypt.
+   * @param  callback   A callback that is triggered after decryption is complete,
+   *                    but before the updated session state has been committed to the session
+   *                    DB.  This allows some implementations to store the committed plaintext
+   *                    to a DB first, in case they are concerned with a crash happening between
+   *                    the time the session state is updated but before they're able to store
+   *                    the plaintext to disk.
+   *
+   * @return The plaintext.
+   * @throws InvalidMessageException if the input is not valid ciphertext.
+   * @throws DuplicateMessageException if the input is a message that has already been received.
+   * @throws LegacyMessageException if the input is a message formatted by a protocol version that
+   *                                is no longer supported.
+   * @throws NoSessionException if there is no established session for this contact.
+   */
+  public byte[] decrypt(WhisperMessage ciphertext, DecryptionCallback callback)
+      throws InvalidMessageException, DuplicateMessageException, LegacyMessageException,
+             NoSessionException
+  {
+    synchronized (SESSION_LOCK) {
+
+      if (!sessionStore.containsSession(recipientId, deviceId)) {
+        throw new NoSessionException("No session for: " + recipientId + ", " + deviceId);
+      }
+
+      SessionRecord sessionRecord = sessionStore.loadSession(recipientId, deviceId);
+      byte[]        plaintext     = decrypt(sessionRecord, ciphertext);
+
+      callback.handlePlaintext(plaintext);
+
+      sessionStore.storeSession(recipientId, deviceId, sessionRecord);
+
+      return plaintext;
+    }
+  }
+
+  private byte[] decrypt(SessionRecord sessionRecord, WhisperMessage ciphertext)
+      throws DuplicateMessageException, LegacyMessageException, InvalidMessageException
+  {
+    synchronized (SESSION_LOCK) {
+      Iterator<SessionState> previousStates = sessionRecord.getPreviousSessionStates().iterator();
+      List<Exception>        exceptions     = new LinkedList<>();
+
+      try {
+        SessionState sessionState = new SessionState(sessionRecord.getSessionState());
+        byte[]       plaintext    = decrypt(sessionState, ciphertext);
+
+        sessionRecord.setState(sessionState);
+        return plaintext;
+      } catch (InvalidMessageException e) {
+        exceptions.add(e);
+      }
+
+      while (previousStates.hasNext()) {
+        try {
+          SessionState promotedState = new SessionState(previousStates.next());
+          byte[]       plaintext     = decrypt(promotedState, ciphertext);
+
+          previousStates.remove();
+          sessionRecord.promoteState(promotedState);
+
+          return plaintext;
+        } catch (InvalidMessageException e) {
+          exceptions.add(e);
+        }
+      }
+
+      throw new InvalidMessageException("No valid sessions.", exceptions);
+    }
+  }
+
+  private byte[] decrypt(SessionState sessionState, WhisperMessage ciphertextMessage)
+      throws InvalidMessageException, DuplicateMessageException, LegacyMessageException
+  {
+    if (!sessionState.hasSenderChain()) {
+      throw new InvalidMessageException("Uninitialized session!");
+    }
+
+    if (ciphertextMessage.getMessageVersion() != sessionState.getSessionVersion()) {
+      throw new InvalidMessageException(String.format("Message version %d, but session version %d",
+                                                      ciphertextMessage.getMessageVersion(),
+                                                      sessionState.getSessionVersion()));
+    }
+
+    int            messageVersion    = ciphertextMessage.getMessageVersion();
+    ECPublicKey    theirEphemeral    = ciphertextMessage.getSenderRatchetKey();
+    int            counter           = ciphertextMessage.getCounter();
+    ChainKey       chainKey          = getOrCreateChainKey(sessionState, theirEphemeral);
+    MessageKeys    messageKeys       = getOrCreateMessageKeys(sessionState, theirEphemeral,
+                                                              chainKey, counter);
+
+    ciphertextMessage.verifyMac(messageVersion,
+                                sessionState.getRemoteIdentityKey(),
+                                sessionState.getLocalIdentityKey(),
+                                messageKeys.getMacKey());
+
+    byte[] plaintext = getPlaintext(messageVersion, messageKeys, ciphertextMessage.getBody());
+
+    sessionState.clearUnacknowledgedPreKeyMessage();
+
+    return plaintext;
+  }
+
+  public int getRemoteRegistrationId() {
+    synchronized (SESSION_LOCK) {
+      SessionRecord record = sessionStore.loadSession(recipientId, deviceId);
+      return record.getSessionState().getRemoteRegistrationId();
+    }
+  }
+
+  public int getSessionVersion() {
+    synchronized (SESSION_LOCK) {
+      if (!sessionStore.containsSession(recipientId, deviceId)) {
+        throw new IllegalStateException(String.format("No session for (%d, %d)!", recipientId, deviceId));
+      }
+
+      SessionRecord record = sessionStore.loadSession(recipientId, deviceId);
+      return record.getSessionState().getSessionVersion();
+    }
+  }
+
+  private ChainKey getOrCreateChainKey(SessionState sessionState, ECPublicKey theirEphemeral)
+      throws InvalidMessageException
+  {
+    try {
+      if (sessionState.hasReceiverChain(theirEphemeral)) {
+        return sessionState.getReceiverChainKey(theirEphemeral);
+      } else {
+        RootKey                 rootKey         = sessionState.getRootKey();
+        ECKeyPair               ourEphemeral    = sessionState.getSenderRatchetKeyPair();
+        Pair<RootKey, ChainKey> receiverChain   = rootKey.createChain(theirEphemeral, ourEphemeral);
+        ECKeyPair               ourNewEphemeral = Curve.generateKeyPair();
+        Pair<RootKey, ChainKey> senderChain     = receiverChain.first().createChain(theirEphemeral, ourNewEphemeral);
+
+        sessionState.setRootKey(senderChain.first());
+        sessionState.addReceiverChain(theirEphemeral, receiverChain.second());
+        sessionState.setPreviousCounter(Math.max(sessionState.getSenderChainKey().getIndex()-1, 0));
+        sessionState.setSenderChain(ourNewEphemeral, senderChain.second());
+
+        return receiverChain.second();
+      }
+    } catch (InvalidKeyException e) {
+      throw new InvalidMessageException(e);
+    }
+  }
+
+  private MessageKeys getOrCreateMessageKeys(SessionState sessionState,
+                                             ECPublicKey theirEphemeral,
+                                             ChainKey chainKey, int counter)
+      throws InvalidMessageException, DuplicateMessageException
+  {
+    if (chainKey.getIndex() > counter) {
+      if (sessionState.hasMessageKeys(theirEphemeral, counter)) {
+        return sessionState.removeMessageKeys(theirEphemeral, counter);
+      } else {
+        throw new DuplicateMessageException("Received message with old counter: " +
+                                                chainKey.getIndex() + " , " + counter);
+      }
+    }
+
+    if (counter - chainKey.getIndex() > 2000) {
+      throw new InvalidMessageException("Over 2000 messages into the future!");
+    }
+
+    while (chainKey.getIndex() < counter) {
+      MessageKeys messageKeys = chainKey.getMessageKeys();
+      sessionState.setMessageKeys(theirEphemeral, messageKeys);
+      chainKey = chainKey.getNextChainKey();
+    }
+
+    sessionState.setReceiverChainKey(theirEphemeral, chainKey.getNextChainKey());
+    return chainKey.getMessageKeys();
+  }
+
+  private byte[] getCiphertext(int version, MessageKeys messageKeys, byte[] plaintext) {
+    try {
+      Cipher cipher;
+
+      if (version >= 3) {
+        cipher = getCipher(Cipher.ENCRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getIv());
+      } else {
+        cipher = getCipher(Cipher.ENCRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getCounter());
+      }
+
+      return cipher.doFinal(plaintext);
+    } catch (IllegalBlockSizeException | BadPaddingException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  private byte[] getPlaintext(int version, MessageKeys messageKeys, byte[] cipherText)
+      throws InvalidMessageException
+  {
+    try {
+      Cipher cipher;
+
+      if (version >= 3) {
+        cipher = getCipher(Cipher.DECRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getIv());
+      } else {
+        cipher = getCipher(Cipher.DECRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getCounter());
+      }
+
+      return cipher.doFinal(cipherText);
+    } catch (IllegalBlockSizeException | BadPaddingException e) {
+      throw new InvalidMessageException(e);
+    }
+  }
+
+  private Cipher getCipher(int mode, SecretKeySpec key, int counter)  {
+    try {
+      Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding");
+
+      byte[] ivBytes = new byte[16];
+      ByteUtil.intToByteArray(ivBytes, 0, counter);
+
+      IvParameterSpec iv = new IvParameterSpec(ivBytes);
+      cipher.init(mode, key, iv);
+
+      return cipher;
+    } catch (NoSuchAlgorithmException | NoSuchPaddingException | java.security.InvalidKeyException |
+             InvalidAlgorithmParameterException e)
+    {
+      throw new AssertionError(e);
+    }
+  }
+
+  private Cipher getCipher(int mode, SecretKeySpec key, IvParameterSpec iv) {
+    try {
+      Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+      cipher.init(mode, key, iv);
+      return cipher;
+    } catch (NoSuchAlgorithmException | NoSuchPaddingException | java.security.InvalidKeyException |
+             InvalidAlgorithmParameterException e)
+    {
+      throw new AssertionError(e);
+    }
+  }
+
+  public static interface DecryptionCallback {
+    public void handlePlaintext(byte[] plaintext);
+  }
+
+  private static class NullDecryptionCallback implements DecryptionCallback {
+    @Override
+    public void handlePlaintext(byte[] plaintext) {}
+  }
+}
\ No newline at end of file
diff --git a/src/main/java/org/whispersystems/libaxolotl/StaleKeyExchangeException.java b/src/main/java/org/whispersystems/libaxolotl/StaleKeyExchangeException.java
new file mode 100644
index 00000000..f94a3008
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/StaleKeyExchangeException.java
@@ -0,0 +1,4 @@
+package org.whispersystems.libaxolotl;
+
+public class StaleKeyExchangeException extends Throwable {
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/UntrustedIdentityException.java b/src/main/java/org/whispersystems/libaxolotl/UntrustedIdentityException.java
new file mode 100644
index 00000000..f434b923
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/UntrustedIdentityException.java
@@ -0,0 +1,4 @@
+package org.whispersystems.libaxolotl;
+
+public class UntrustedIdentityException extends Exception {
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ecc/Curve.java b/src/main/java/org/whispersystems/libaxolotl/ecc/Curve.java
new file mode 100644
index 00000000..66b8cc3a
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ecc/Curve.java
@@ -0,0 +1,78 @@
+/**
+ * Copyright (C) 2013 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.ecc;
+
+import org.whispersystems.libaxolotl.InvalidKeyException;
+
+public class Curve {
+
+  public  static final int DJB_TYPE   = 0x05;
+
+  public static ECKeyPair generateKeyPair() {
+    return Curve25519.generateKeyPair();
+  }
+
+  public static ECPublicKey decodePoint(byte[] bytes, int offset)
+      throws InvalidKeyException
+  {
+    int type = bytes[offset];
+
+    if (type == DJB_TYPE) {
+      return Curve25519.decodePoint(bytes, offset);
+    } else {
+      throw new InvalidKeyException("Unknown key type: " + type);
+    }
+  }
+
+  public static ECPrivateKey decodePrivatePoint(byte[] bytes) {
+    return new DjbECPrivateKey(bytes);
+  }
+
+  public static byte[] calculateAgreement(ECPublicKey publicKey, ECPrivateKey privateKey)
+      throws InvalidKeyException
+  {
+    if (publicKey.getType() != privateKey.getType()) {
+      throw new InvalidKeyException("Public and private keys must be of the same type!");
+    }
+
+    if (publicKey.getType() == DJB_TYPE) {
+      return Curve25519.calculateAgreement(publicKey, privateKey);
+    } else {
+      throw new InvalidKeyException("Unknown type: " + publicKey.getType());
+    }
+  }
+
+  public static boolean verifySignature(ECPublicKey signingKey, byte[] message, byte[] signature)
+      throws InvalidKeyException
+  {
+    if (signingKey.getType() == DJB_TYPE) {
+      return Curve25519.verifySignature(signingKey, message, signature);
+    } else {
+      throw new InvalidKeyException("Unknown type: " + signingKey.getType());
+    }
+  }
+
+  public static byte[] calculateSignature(ECPrivateKey signingKey, byte[] message)
+      throws InvalidKeyException
+  {
+    if (signingKey.getType() == DJB_TYPE) {
+      return Curve25519.calculateSignature(signingKey, message);
+    } else {
+      throw new InvalidKeyException("Unknown type: " + signingKey.getType());
+    }
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ecc/Curve25519.java b/src/main/java/org/whispersystems/libaxolotl/ecc/Curve25519.java
new file mode 100644
index 00000000..685a4a11
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ecc/Curve25519.java
@@ -0,0 +1,98 @@
+/**
+ * Copyright (C) 2013 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.ecc;
+
+import org.whispersystems.libaxolotl.InvalidKeyException;
+
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+
+public class Curve25519 {
+
+  static {
+    System.loadLibrary("curve25519");
+
+    try {
+      random = SecureRandom.getInstance("SHA1PRNG");
+    } catch (NoSuchAlgorithmException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  private static final SecureRandom random;
+
+  private static native byte[] calculateAgreement(byte[] ourPrivate, byte[] theirPublic);
+  private static native byte[] generatePublicKey(byte[] privateKey);
+  private static native byte[] generatePrivateKey(byte[] random);
+
+  private static native byte[]  calculateSignature(byte[] random, byte[] privateKey, byte[] message);
+  private static native boolean verifySignature(byte[] publicKey, byte[] message, byte[] signature);
+
+  public static ECKeyPair generateKeyPair() {
+    byte[] privateKey = generatePrivateKey();
+    byte[] publicKey  = generatePublicKey(privateKey);
+
+    return new ECKeyPair(new DjbECPublicKey(publicKey), new DjbECPrivateKey(privateKey));
+  }
+
+  static byte[] calculateAgreement(ECPublicKey publicKey, ECPrivateKey privateKey) {
+    return calculateAgreement(((DjbECPrivateKey)privateKey).getPrivateKey(),
+                              ((DjbECPublicKey)publicKey).getPublicKey());
+  }
+
+  static byte[] calculateSignature(ECPrivateKey privateKey, byte[] message) {
+    byte[] random = getRandom(64);
+    return calculateSignature(random, ((DjbECPrivateKey)privateKey).getPrivateKey(), message);
+  }
+
+  static boolean verifySignature(ECPublicKey publicKey, byte[] message, byte[] signature) {
+    return verifySignature(((DjbECPublicKey)publicKey).getPublicKey(), message, signature);
+  }
+
+  static ECPublicKey decodePoint(byte[] encoded, int offset)
+      throws InvalidKeyException
+  {
+    int    type     = encoded[offset] & 0xFF;
+    byte[] keyBytes = new byte[32];
+    System.arraycopy(encoded, offset+1, keyBytes, 0, keyBytes.length);
+
+    if (type != Curve.DJB_TYPE) {
+      throw new InvalidKeyException("Bad key type: " + type);
+    }
+
+    return new DjbECPublicKey(keyBytes);
+  }
+
+  private static byte[] generatePrivateKey() {
+    byte[] privateKey = new byte[32];
+    random.nextBytes(privateKey);
+
+    return generatePrivateKey(privateKey);
+  }
+
+  private static byte[] getRandom(int size) {
+    try {
+      byte[] random = new byte[size];
+      SecureRandom.getInstance("SHA1PRNG").nextBytes(random);
+
+      return random;
+    } catch (NoSuchAlgorithmException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ecc/DjbECPrivateKey.java b/src/main/java/org/whispersystems/libaxolotl/ecc/DjbECPrivateKey.java
new file mode 100644
index 00000000..ecb55b4e
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ecc/DjbECPrivateKey.java
@@ -0,0 +1,41 @@
+/**
+ * Copyright (C) 2013 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.whispersystems.libaxolotl.ecc;
+
+public class DjbECPrivateKey implements ECPrivateKey {
+
+  private final byte[] privateKey;
+
+  DjbECPrivateKey(byte[] privateKey) {
+    this.privateKey = privateKey;
+  }
+
+  @Override
+  public byte[] serialize() {
+    return privateKey;
+  }
+
+  @Override
+  public int getType() {
+    return Curve.DJB_TYPE;
+  }
+
+  public byte[] getPrivateKey() {
+    return privateKey;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ecc/DjbECPublicKey.java b/src/main/java/org/whispersystems/libaxolotl/ecc/DjbECPublicKey.java
new file mode 100644
index 00000000..9f66d439
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ecc/DjbECPublicKey.java
@@ -0,0 +1,66 @@
+/**
+ * Copyright (C) 2013 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.whispersystems.libaxolotl.ecc;
+
+import org.whispersystems.libaxolotl.util.ByteUtil;
+
+import java.math.BigInteger;
+import java.util.Arrays;
+
+public class DjbECPublicKey implements ECPublicKey {
+
+  private final byte[] publicKey;
+
+  DjbECPublicKey(byte[] publicKey) {
+    this.publicKey = publicKey;
+  }
+
+  @Override
+  public byte[] serialize() {
+    byte[] type = {Curve.DJB_TYPE};
+    return ByteUtil.combine(type, publicKey);
+  }
+
+  @Override
+  public int getType() {
+    return Curve.DJB_TYPE;
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    if (other == null)                      return false;
+    if (!(other instanceof DjbECPublicKey)) return false;
+
+    DjbECPublicKey that = (DjbECPublicKey)other;
+    return Arrays.equals(this.publicKey, that.publicKey);
+  }
+
+  @Override
+  public int hashCode() {
+    return Arrays.hashCode(publicKey);
+  }
+
+  @Override
+  public int compareTo(ECPublicKey another) {
+    return new BigInteger(publicKey).compareTo(new BigInteger(((DjbECPublicKey)another).publicKey));
+  }
+
+  public byte[] getPublicKey() {
+    return publicKey;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ecc/ECKeyPair.java b/src/main/java/org/whispersystems/libaxolotl/ecc/ECKeyPair.java
new file mode 100644
index 00000000..bcaec927
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ecc/ECKeyPair.java
@@ -0,0 +1,37 @@
+/**
+ * Copyright (C) 2013 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.whispersystems.libaxolotl.ecc;
+
+public class ECKeyPair {
+
+  private final ECPublicKey  publicKey;
+  private final ECPrivateKey privateKey;
+
+  public ECKeyPair(ECPublicKey publicKey, ECPrivateKey privateKey) {
+    this.publicKey = publicKey;
+    this.privateKey = privateKey;
+  }
+
+  public ECPublicKey getPublicKey() {
+    return publicKey;
+  }
+
+  public ECPrivateKey getPrivateKey() {
+    return privateKey;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ecc/ECPrivateKey.java b/src/main/java/org/whispersystems/libaxolotl/ecc/ECPrivateKey.java
new file mode 100644
index 00000000..922057de
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ecc/ECPrivateKey.java
@@ -0,0 +1,23 @@
+/**
+ * Copyright (C) 2013 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.whispersystems.libaxolotl.ecc;
+
+public interface ECPrivateKey {
+  public byte[] serialize();
+  public int getType();
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ecc/ECPublicKey.java b/src/main/java/org/whispersystems/libaxolotl/ecc/ECPublicKey.java
new file mode 100644
index 00000000..12576807
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ecc/ECPublicKey.java
@@ -0,0 +1,27 @@
+/**
+ * Copyright (C) 2013 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.whispersystems.libaxolotl.ecc;
+
+public interface ECPublicKey extends Comparable<ECPublicKey> {
+
+  public static final int KEY_SIZE = 33;
+
+  public byte[] serialize();
+
+  public int getType();
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/groups/GroupCipher.java b/src/main/java/org/whispersystems/libaxolotl/groups/GroupCipher.java
new file mode 100644
index 00000000..43dac752
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/groups/GroupCipher.java
@@ -0,0 +1,146 @@
+package org.whispersystems.libaxolotl.groups;
+
+import org.whispersystems.libaxolotl.DuplicateMessageException;
+import org.whispersystems.libaxolotl.InvalidKeyIdException;
+import org.whispersystems.libaxolotl.InvalidMessageException;
+import org.whispersystems.libaxolotl.LegacyMessageException;
+import org.whispersystems.libaxolotl.NoSessionException;
+import org.whispersystems.libaxolotl.groups.ratchet.SenderChainKey;
+import org.whispersystems.libaxolotl.groups.ratchet.SenderMessageKey;
+import org.whispersystems.libaxolotl.groups.state.SenderKeyRecord;
+import org.whispersystems.libaxolotl.groups.state.SenderKeyState;
+import org.whispersystems.libaxolotl.groups.state.SenderKeyStore;
+import org.whispersystems.libaxolotl.protocol.SenderKeyMessage;
+
+import java.security.InvalidAlgorithmParameterException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+public class GroupCipher {
+
+  static final Object LOCK = new Object();
+
+  private final SenderKeyStore senderKeyStore;
+  private final String         senderKeyId;
+
+  public GroupCipher(SenderKeyStore senderKeyStore, String senderKeyId) {
+    this.senderKeyStore = senderKeyStore;
+    this.senderKeyId    = senderKeyId;
+  }
+
+  public byte[] encrypt(byte[] paddedPlaintext) throws NoSessionException {
+    synchronized (LOCK) {
+      try {
+        SenderKeyRecord  record         = senderKeyStore.loadSenderKey(senderKeyId);
+        SenderKeyState   senderKeyState = record.getSenderKeyState();
+        SenderMessageKey senderKey      = senderKeyState.getSenderChainKey().getSenderMessageKey();
+        byte[]           ciphertext     = getCipherText(senderKey.getIv(), senderKey.getCipherKey(), paddedPlaintext);
+
+        SenderKeyMessage senderKeyMessage = new SenderKeyMessage(senderKeyState.getKeyId(),
+                                                                 senderKey.getIteration(),
+                                                                 ciphertext,
+                                                                 senderKeyState.getSigningKeyPrivate());
+
+        senderKeyState.setSenderChainKey(senderKeyState.getSenderChainKey().getNext());
+
+        senderKeyStore.storeSenderKey(senderKeyId, record);
+
+        return senderKeyMessage.serialize();
+      } catch (InvalidKeyIdException e) {
+        throw new NoSessionException(e);
+      }
+    }
+  }
+
+  public byte[] decrypt(byte[] senderKeyMessageBytes)
+      throws LegacyMessageException, InvalidMessageException, DuplicateMessageException
+  {
+    synchronized (LOCK) {
+      try {
+        SenderKeyRecord  record           = senderKeyStore.loadSenderKey(senderKeyId);
+        SenderKeyMessage senderKeyMessage = new SenderKeyMessage(senderKeyMessageBytes);
+        SenderKeyState   senderKeyState   = record.getSenderKeyState(senderKeyMessage.getKeyId());
+
+        senderKeyMessage.verifySignature(senderKeyState.getSigningKeyPublic());
+
+        SenderMessageKey senderKey = getSenderKey(senderKeyState, senderKeyMessage.getIteration());
+
+        byte[] plaintext = getPlainText(senderKey.getIv(), senderKey.getCipherKey(), senderKeyMessage.getCipherText());
+
+        senderKeyStore.storeSenderKey(senderKeyId, record);
+
+        return plaintext;
+      } catch (org.whispersystems.libaxolotl.InvalidKeyException | InvalidKeyIdException e) {
+        throw new InvalidMessageException(e);
+      }
+    }
+  }
+
+  private SenderMessageKey getSenderKey(SenderKeyState senderKeyState, int iteration)
+      throws DuplicateMessageException, InvalidMessageException
+  {
+    SenderChainKey senderChainKey = senderKeyState.getSenderChainKey();
+
+    if (senderChainKey.getIteration() > iteration) {
+      if (senderKeyState.hasSenderMessageKey(iteration)) {
+        return senderKeyState.removeSenderMessageKey(iteration);
+      } else {
+        throw new DuplicateMessageException("Received message with old counter: " +
+                                            senderChainKey.getIteration() + " , " + iteration);
+      }
+    }
+
+    if (senderChainKey.getIteration() - iteration > 2000) {
+      throw new InvalidMessageException("Over 2000 messages into the future!");
+    }
+
+    while (senderChainKey.getIteration() < iteration) {
+      senderKeyState.addSenderMessageKey(senderChainKey.getSenderMessageKey());
+      senderChainKey = senderChainKey.getNext();
+    }
+
+    senderKeyState.setSenderChainKey(senderChainKey.getNext());
+    return senderChainKey.getSenderMessageKey();
+  }
+
+  private byte[] getPlainText(byte[] iv, byte[] key, byte[] ciphertext)
+      throws InvalidMessageException
+  {
+    try {
+      IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
+      Cipher          cipher          = Cipher.getInstance("AES/CBC/PKCS5Padding");
+
+      cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(key, "AES"), ivParameterSpec);
+
+      return cipher.doFinal(ciphertext);
+    } catch (NoSuchAlgorithmException | NoSuchPaddingException | java.security.InvalidKeyException |
+             InvalidAlgorithmParameterException e)
+    {
+      throw new AssertionError(e);
+    } catch (IllegalBlockSizeException | BadPaddingException e) {
+      throw new InvalidMessageException(e);
+    }
+  }
+
+  private byte[] getCipherText(byte[] iv, byte[] key, byte[] plaintext) {
+    try {
+      IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
+      Cipher          cipher          = Cipher.getInstance("AES/CBC/PKCS5Padding");
+
+      cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "AES"), ivParameterSpec);
+
+      return cipher.doFinal(plaintext);
+    } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidAlgorithmParameterException |
+             IllegalBlockSizeException | BadPaddingException | java.security.InvalidKeyException e)
+    {
+      throw new AssertionError(e);
+    }
+  }
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/groups/GroupSessionBuilder.java b/src/main/java/org/whispersystems/libaxolotl/groups/GroupSessionBuilder.java
new file mode 100644
index 00000000..8b73484b
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/groups/GroupSessionBuilder.java
@@ -0,0 +1,38 @@
+package org.whispersystems.libaxolotl.groups;
+
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.groups.state.SenderKeyRecord;
+import org.whispersystems.libaxolotl.groups.state.SenderKeyStore;
+import org.whispersystems.libaxolotl.protocol.SenderKeyDistributionMessage;
+
+public class GroupSessionBuilder {
+
+  private final SenderKeyStore senderKeyStore;
+
+  public GroupSessionBuilder(SenderKeyStore senderKeyStore) {
+    this.senderKeyStore = senderKeyStore;
+  }
+
+  public void process(String sender, SenderKeyDistributionMessage senderKeyDistributionMessage) {
+    synchronized (GroupCipher.LOCK) {
+      SenderKeyRecord senderKeyRecord = senderKeyStore.loadSenderKey(sender);
+      senderKeyRecord.addSenderKeyState(senderKeyDistributionMessage.getId(),
+                                        senderKeyDistributionMessage.getIteration(),
+                                        senderKeyDistributionMessage.getChainKey(),
+                                        senderKeyDistributionMessage.getSignatureKey());
+      senderKeyStore.storeSenderKey(sender, senderKeyRecord);
+    }
+  }
+
+  public SenderKeyDistributionMessage process(String groupId, int keyId, int iteration,
+                                              byte[] chainKey, ECKeyPair signatureKey)
+  {
+    synchronized (GroupCipher.LOCK) {
+      SenderKeyRecord senderKeyRecord = senderKeyStore.loadSenderKey(groupId);
+      senderKeyRecord.setSenderKeyState(keyId, iteration, chainKey, signatureKey);
+      senderKeyStore.storeSenderKey(groupId, senderKeyRecord);
+
+      return new SenderKeyDistributionMessage(keyId, iteration, chainKey, signatureKey.getPublicKey());
+    }
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/groups/ratchet/SenderChainKey.java b/src/main/java/org/whispersystems/libaxolotl/groups/ratchet/SenderChainKey.java
new file mode 100644
index 00000000..71375923
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/groups/ratchet/SenderChainKey.java
@@ -0,0 +1,49 @@
+package org.whispersystems.libaxolotl.groups.ratchet;
+
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+
+public class SenderChainKey {
+
+  private static final byte[] MESSAGE_KEY_SEED = {0x01};
+  private static final byte[] CHAIN_KEY_SEED   = {0x02};
+
+  private final int    iteration;
+  private final byte[] chainKey;
+
+  public SenderChainKey(int iteration, byte[] chainKey) {
+    this.iteration = iteration;
+    this.chainKey  = chainKey;
+  }
+
+  public int getIteration() {
+    return iteration;
+  }
+
+  public SenderMessageKey getSenderMessageKey() {
+    return new SenderMessageKey(iteration, getDerivative(MESSAGE_KEY_SEED, chainKey));
+  }
+
+  public SenderChainKey getNext() {
+    return new SenderChainKey(iteration + 1, getDerivative(CHAIN_KEY_SEED, chainKey));
+  }
+
+  public byte[] getSeed() {
+    return chainKey;
+  }
+
+  private byte[] getDerivative(byte[] seed, byte[] key) {
+    try {
+      Mac mac = Mac.getInstance("HmacSHA256");
+      mac.init(new SecretKeySpec(key, "HmacSHA256"));
+
+      return mac.doFinal(seed);
+    } catch (NoSuchAlgorithmException | InvalidKeyException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/groups/ratchet/SenderMessageKey.java b/src/main/java/org/whispersystems/libaxolotl/groups/ratchet/SenderMessageKey.java
new file mode 100644
index 00000000..8808a8e8
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/groups/ratchet/SenderMessageKey.java
@@ -0,0 +1,38 @@
+package org.whispersystems.libaxolotl.groups.ratchet;
+
+import org.whispersystems.libaxolotl.kdf.HKDFv3;
+import org.whispersystems.libaxolotl.util.ByteUtil;
+
+public class SenderMessageKey {
+
+  private final int    iteration;
+  private final byte[] iv;
+  private final byte[] cipherKey;
+  private final byte[] seed;
+
+  public SenderMessageKey(int iteration, byte[] seed) {
+    byte[] derivative = new HKDFv3().deriveSecrets(seed, "WhisperGroup".getBytes(), 48);
+    byte[][] parts    = ByteUtil.split(derivative, 16, 32);
+
+    this.iteration = iteration;
+    this.seed      = seed;
+    this.iv        = parts[0];
+    this.cipherKey = parts[1];
+  }
+
+  public int getIteration() {
+    return iteration;
+  }
+
+  public byte[] getIv() {
+    return iv;
+  }
+
+  public byte[] getCipherKey() {
+    return cipherKey;
+  }
+
+  public byte[] getSeed() {
+    return seed;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/groups/state/SenderKeyRecord.java b/src/main/java/org/whispersystems/libaxolotl/groups/state/SenderKeyRecord.java
new file mode 100644
index 00000000..bb1ba952
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/groups/state/SenderKeyRecord.java
@@ -0,0 +1,64 @@
+package org.whispersystems.libaxolotl.groups.state;
+
+import org.whispersystems.libaxolotl.InvalidKeyIdException;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.state.StorageProtos;
+
+import java.io.IOException;
+import java.util.LinkedList;
+import java.util.List;
+
+import static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure;
+
+public class SenderKeyRecord {
+
+  private List<SenderKeyState> senderKeyStates = new LinkedList<>();
+
+  public SenderKeyRecord() {}
+
+  public SenderKeyRecord(byte[] serialized) throws IOException {
+    SenderKeyRecordStructure senderKeyRecordStructure = SenderKeyRecordStructure.parseFrom(serialized);
+
+    for (StorageProtos.SenderKeyStateStructure structure : senderKeyRecordStructure.getSenderKeyStatesList()) {
+      this.senderKeyStates.add(new SenderKeyState(structure));
+    }
+  }
+
+  public SenderKeyState getSenderKeyState() throws InvalidKeyIdException {
+    if (!senderKeyStates.isEmpty()) {
+      return senderKeyStates.get(0);
+    } else {
+      throw new InvalidKeyIdException("No key state in record!");
+    }
+  }
+
+  public SenderKeyState getSenderKeyState(int keyId) throws InvalidKeyIdException {
+    for (SenderKeyState state : senderKeyStates) {
+      if (state.getKeyId() == keyId) {
+        return state;
+      }
+    }
+
+    throw new InvalidKeyIdException("No keys for: " + keyId);
+  }
+
+  public void addSenderKeyState(int id, int iteration, byte[] chainKey, ECPublicKey signatureKey) {
+    senderKeyStates.add(new SenderKeyState(id, iteration, chainKey, signatureKey));
+  }
+
+  public void setSenderKeyState(int id, int iteration, byte[] chainKey, ECKeyPair signatureKey) {
+    senderKeyStates.clear();
+    senderKeyStates.add(new SenderKeyState(id, iteration, chainKey, signatureKey));
+  }
+
+  public byte[] serialize() {
+    SenderKeyRecordStructure.Builder recordStructure = SenderKeyRecordStructure.newBuilder();
+
+    for (SenderKeyState senderKeyState : senderKeyStates) {
+      recordStructure.addSenderKeyStates(senderKeyState.getStructure());
+    }
+
+    return recordStructure.build().toByteArray();
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/groups/state/SenderKeyState.java b/src/main/java/org/whispersystems/libaxolotl/groups/state/SenderKeyState.java
new file mode 100644
index 00000000..80498ce0
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/groups/state/SenderKeyState.java
@@ -0,0 +1,144 @@
+package org.whispersystems.libaxolotl.groups.state;
+
+import com.google.protobuf.ByteString;
+
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPrivateKey;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.groups.ratchet.SenderChainKey;
+import org.whispersystems.libaxolotl.groups.ratchet.SenderMessageKey;
+import org.whispersystems.libaxolotl.util.guava.Optional;
+
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+
+import static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure;
+
+public class SenderKeyState {
+
+  private SenderKeyStateStructure senderKeyStateStructure;
+
+  public SenderKeyState(int id, int iteration, byte[] chainKey, ECPublicKey signatureKey) {
+    this(id, iteration, chainKey, signatureKey, Optional.<ECPrivateKey>absent());
+  }
+
+  public SenderKeyState(int id, int iteration, byte[] chainKey, ECKeyPair signatureKey) {
+    this(id, iteration, chainKey, signatureKey.getPublicKey(), Optional.of(signatureKey.getPrivateKey()));
+  }
+
+  private SenderKeyState(int id, int iteration, byte[] chainKey,
+                        ECPublicKey signatureKeyPublic,
+                        Optional<ECPrivateKey> signatureKeyPrivate)
+  {
+    SenderKeyStateStructure.SenderChainKey senderChainKeyStructure =
+        SenderKeyStateStructure.SenderChainKey.newBuilder()
+                                              .setIteration(iteration)
+                                              .setSeed(ByteString.copyFrom(chainKey))
+                                              .build();
+
+    SenderKeyStateStructure.SenderSigningKey.Builder signingKeyStructure =
+        SenderKeyStateStructure.SenderSigningKey.newBuilder()
+                                                .setPublic(ByteString.copyFrom(signatureKeyPublic.serialize()));
+
+    if (signatureKeyPrivate.isPresent()) {
+      signingKeyStructure.setPrivate(ByteString.copyFrom(signatureKeyPrivate.get().serialize()));
+    }
+
+    this.senderKeyStateStructure = SenderKeyStateStructure.newBuilder()
+                                                          .setSenderKeyId(id)
+                                                          .setSenderChainKey(senderChainKeyStructure)
+                                                          .setSenderSigningKey(signingKeyStructure)
+                                                          .build();
+  }
+
+  public SenderKeyState(SenderKeyStateStructure senderKeyStateStructure) {
+    this.senderKeyStateStructure = senderKeyStateStructure;
+  }
+
+  public int getKeyId() {
+    return senderKeyStateStructure.getSenderKeyId();
+  }
+
+  public SenderChainKey getSenderChainKey() {
+    return new SenderChainKey(senderKeyStateStructure.getSenderChainKey().getIteration(),
+                              senderKeyStateStructure.getSenderChainKey().getSeed().toByteArray());
+  }
+
+  public void setSenderChainKey(SenderChainKey chainKey) {
+    SenderKeyStateStructure.SenderChainKey senderChainKeyStructure =
+        SenderKeyStateStructure.SenderChainKey.newBuilder()
+                                              .setIteration(chainKey.getIteration())
+                                              .setSeed(ByteString.copyFrom(chainKey.getSeed()))
+                                              .build();
+
+    this.senderKeyStateStructure = senderKeyStateStructure.toBuilder()
+                                                          .setSenderChainKey(senderChainKeyStructure)
+                                                          .build();
+  }
+
+  public ECPublicKey getSigningKeyPublic() throws InvalidKeyException {
+    return Curve.decodePoint(senderKeyStateStructure.getSenderSigningKey()
+                                                    .getPublic()
+                                                    .toByteArray(), 0);
+  }
+
+  public ECPrivateKey getSigningKeyPrivate() {
+    return Curve.decodePrivatePoint(senderKeyStateStructure.getSenderSigningKey()
+                                                           .getPrivate().toByteArray());
+  }
+
+  public boolean hasSenderMessageKey(int iteration) {
+    for (SenderKeyStateStructure.SenderMessageKey senderMessageKey : senderKeyStateStructure.getSenderMessageKeysList()) {
+      if (senderMessageKey.getIteration() == iteration) return true;
+    }
+
+    return false;
+  }
+
+  public void addSenderMessageKey(SenderMessageKey senderMessageKey) {
+    SenderKeyStateStructure.SenderMessageKey senderMessageKeyStructure =
+        SenderKeyStateStructure.SenderMessageKey.newBuilder()
+                                                .setIteration(senderMessageKey.getIteration())
+                                                .setSeed(ByteString.copyFrom(senderMessageKey.getSeed()))
+                                                .build();
+
+    this.senderKeyStateStructure = this.senderKeyStateStructure.toBuilder()
+                                                               .addSenderMessageKeys(senderMessageKeyStructure)
+                                                               .build();
+  }
+
+  public SenderMessageKey removeSenderMessageKey(int iteration) {
+    List<SenderKeyStateStructure.SenderMessageKey>     keys     = new LinkedList<>(senderKeyStateStructure.getSenderMessageKeysList());
+    Iterator<SenderKeyStateStructure.SenderMessageKey> iterator = keys.iterator();
+
+    SenderKeyStateStructure.SenderMessageKey result = null;
+
+    while (iterator.hasNext()) {
+      SenderKeyStateStructure.SenderMessageKey senderMessageKey = iterator.next();
+
+      if (senderMessageKey.getIteration() == iteration) {
+        result = senderMessageKey;
+        iterator.remove();
+        break;
+      }
+    }
+
+    this.senderKeyStateStructure = this.senderKeyStateStructure.toBuilder()
+                                                               .clearSenderMessageKeys()
+                                                               .addAllSenderMessageKeys(keys)
+                                                               .build();
+
+    if (result != null) {
+      return new SenderMessageKey(result.getIteration(), result.getSeed().toByteArray());
+    } else {
+      return null;
+    }
+  }
+
+  public SenderKeyStateStructure getStructure() {
+    return senderKeyStateStructure;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/groups/state/SenderKeyStore.java b/src/main/java/org/whispersystems/libaxolotl/groups/state/SenderKeyStore.java
new file mode 100644
index 00000000..da01b1f3
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/groups/state/SenderKeyStore.java
@@ -0,0 +1,6 @@
+package org.whispersystems.libaxolotl.groups.state;
+
+public interface SenderKeyStore {
+  public void storeSenderKey(String senderKeyId, SenderKeyRecord record);
+  public SenderKeyRecord loadSenderKey(String senderKeyId);
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/kdf/DerivedMessageSecrets.java b/src/main/java/org/whispersystems/libaxolotl/kdf/DerivedMessageSecrets.java
new file mode 100644
index 00000000..b3f54fb8
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/kdf/DerivedMessageSecrets.java
@@ -0,0 +1,61 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.whispersystems.libaxolotl.kdf;
+
+import org.whispersystems.libaxolotl.util.ByteUtil;
+
+import java.text.ParseException;
+
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+public class DerivedMessageSecrets {
+
+  public  static final int SIZE              = 80;
+  private static final int CIPHER_KEY_LENGTH = 32;
+  private static final int MAC_KEY_LENGTH    = 32;
+  private static final int IV_LENGTH         = 16;
+
+  private final SecretKeySpec   cipherKey;
+  private final SecretKeySpec   macKey;
+  private final IvParameterSpec iv;
+
+  public DerivedMessageSecrets(byte[] okm) {
+    try {
+      byte[][] keys = ByteUtil.split(okm, CIPHER_KEY_LENGTH, MAC_KEY_LENGTH, IV_LENGTH);
+
+      this.cipherKey = new SecretKeySpec(keys[0], "AES");
+      this.macKey    = new SecretKeySpec(keys[1], "HmacSHA256");
+      this.iv        = new IvParameterSpec(keys[2]);
+    } catch (ParseException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public SecretKeySpec getCipherKey() {
+    return cipherKey;
+  }
+
+  public SecretKeySpec getMacKey() {
+    return macKey;
+  }
+
+  public IvParameterSpec getIv() {
+    return iv;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/kdf/DerivedRootSecrets.java b/src/main/java/org/whispersystems/libaxolotl/kdf/DerivedRootSecrets.java
new file mode 100644
index 00000000..82cc541d
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/kdf/DerivedRootSecrets.java
@@ -0,0 +1,26 @@
+package org.whispersystems.libaxolotl.kdf;
+
+import org.whispersystems.libaxolotl.util.ByteUtil;
+
+public class DerivedRootSecrets {
+
+  public static final int SIZE = 64;
+
+  private final byte[] rootKey;
+  private final byte[] chainKey;
+
+  public DerivedRootSecrets(byte[] okm) {
+    byte[][] keys = ByteUtil.split(okm, 32, 32);
+    this.rootKey  = keys[0];
+    this.chainKey = keys[1];
+  }
+
+  public byte[] getRootKey() {
+    return rootKey;
+  }
+
+  public byte[] getChainKey() {
+    return chainKey;
+  }
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/kdf/HKDF.java b/src/main/java/org/whispersystems/libaxolotl/kdf/HKDF.java
new file mode 100644
index 00000000..d190822d
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/kdf/HKDF.java
@@ -0,0 +1,93 @@
+/**
+ * Copyright (C) 2013 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.whispersystems.libaxolotl.kdf;
+
+import java.io.ByteArrayOutputStream;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+
+public abstract class HKDF {
+
+  private static final int HASH_OUTPUT_SIZE  = 32;
+
+  public static HKDF createFor(int messageVersion) {
+    switch (messageVersion) {
+      case 2:  return new HKDFv2();
+      case 3:  return new HKDFv3();
+      default: throw new AssertionError("Unknown version: " + messageVersion);
+    }
+  }
+
+  public byte[] deriveSecrets(byte[] inputKeyMaterial, byte[] info, int outputLength) {
+    byte[] salt = new byte[HASH_OUTPUT_SIZE];
+    return deriveSecrets(inputKeyMaterial, salt, info, outputLength);
+  }
+
+  public byte[] deriveSecrets(byte[] inputKeyMaterial, byte[] salt, byte[] info, int outputLength) {
+    byte[] prk = extract(salt, inputKeyMaterial);
+    return expand(prk, info, outputLength);
+  }
+
+  private byte[] extract(byte[] salt, byte[] inputKeyMaterial) {
+    try {
+      Mac mac = Mac.getInstance("HmacSHA256");
+      mac.init(new SecretKeySpec(salt, "HmacSHA256"));
+      return mac.doFinal(inputKeyMaterial);
+    } catch (NoSuchAlgorithmException | InvalidKeyException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  private byte[] expand(byte[] prk, byte[] info, int outputSize) {
+    try {
+      int                   iterations     = (int) Math.ceil((double) outputSize / (double) HASH_OUTPUT_SIZE);
+      byte[]                mixin          = new byte[0];
+      ByteArrayOutputStream results        = new ByteArrayOutputStream();
+      int                   remainingBytes = outputSize;
+
+      for (int i= getIterationStartOffset();i<iterations + getIterationStartOffset();i++) {
+        Mac mac = Mac.getInstance("HmacSHA256");
+        mac.init(new SecretKeySpec(prk, "HmacSHA256"));
+
+        mac.update(mixin);
+        if (info != null) {
+          mac.update(info);
+        }
+        mac.update((byte)i);
+
+        byte[] stepResult = mac.doFinal();
+        int    stepSize   = Math.min(remainingBytes, stepResult.length);
+
+        results.write(stepResult, 0, stepSize);
+
+        mixin          = stepResult;
+        remainingBytes -= stepSize;
+      }
+
+      return results.toByteArray();
+    } catch (NoSuchAlgorithmException | InvalidKeyException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  protected abstract int getIterationStartOffset();
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/kdf/HKDFv2.java b/src/main/java/org/whispersystems/libaxolotl/kdf/HKDFv2.java
new file mode 100644
index 00000000..86e4bf5f
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/kdf/HKDFv2.java
@@ -0,0 +1,8 @@
+package org.whispersystems.libaxolotl.kdf;
+
+public class HKDFv2 extends HKDF {
+  @Override
+  protected int getIterationStartOffset() {
+    return 0;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/kdf/HKDFv3.java b/src/main/java/org/whispersystems/libaxolotl/kdf/HKDFv3.java
new file mode 100644
index 00000000..a1934c90
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/kdf/HKDFv3.java
@@ -0,0 +1,8 @@
+package org.whispersystems.libaxolotl.kdf;
+
+public class HKDFv3 extends HKDF {
+  @Override
+  protected int getIterationStartOffset() {
+    return 1;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/protocol/CiphertextMessage.java b/src/main/java/org/whispersystems/libaxolotl/protocol/CiphertextMessage.java
new file mode 100644
index 00000000..cf4be756
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/protocol/CiphertextMessage.java
@@ -0,0 +1,35 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.protocol;
+
+public interface CiphertextMessage {
+
+  public static final int UNSUPPORTED_VERSION = 1;
+  public static final int CURRENT_VERSION     = 3;
+
+  public static final int WHISPER_TYPE                = 2;
+  public static final int PREKEY_TYPE                 = 3;
+  public static final int SENDERKEY_TYPE              = 4;
+  public static final int SENDERKEY_DISTRIBUTION_TYPE = 5;
+
+  // This should be the worst case (worse than V2).  So not always accurate, but good enough for padding.
+  public static final int ENCRYPTED_MESSAGE_OVERHEAD = 53;
+
+  public byte[] serialize();
+  public int getType();
+
+}
\ No newline at end of file
diff --git a/src/main/java/org/whispersystems/libaxolotl/protocol/KeyExchangeMessage.java b/src/main/java/org/whispersystems/libaxolotl/protocol/KeyExchangeMessage.java
new file mode 100644
index 00000000..bec9208c
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/protocol/KeyExchangeMessage.java
@@ -0,0 +1,153 @@
+package org.whispersystems.libaxolotl.protocol;
+
+
+import com.google.protobuf.ByteString;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.InvalidMessageException;
+import org.whispersystems.libaxolotl.InvalidVersionException;
+import org.whispersystems.libaxolotl.LegacyMessageException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.util.ByteUtil;
+
+import java.io.IOException;
+
+import static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage.Builder;
+
+public class KeyExchangeMessage {
+
+  public static final int INITIATE_FLAG              = 0x01;
+  public static final int RESPONSE_FLAG              = 0X02;
+  public static final int SIMULTAENOUS_INITIATE_FLAG = 0x04;
+
+  private final int         version;
+  private final int         supportedVersion;
+  private final int         sequence;
+  private final int         flags;
+
+  private final ECPublicKey baseKey;
+  private final byte[]      baseKeySignature;
+  private final ECPublicKey ratchetKey;
+  private final IdentityKey identityKey;
+  private final byte[]      serialized;
+
+  public KeyExchangeMessage(int messageVersion, int sequence, int flags,
+                            ECPublicKey baseKey, byte[] baseKeySignature,
+                            ECPublicKey ratchetKey,
+                            IdentityKey identityKey)
+  {
+    this.supportedVersion = CiphertextMessage.CURRENT_VERSION;
+    this.version          = messageVersion;
+    this.sequence         = sequence;
+    this.flags            = flags;
+    this.baseKey          = baseKey;
+    this.baseKeySignature = baseKeySignature;
+    this.ratchetKey       = ratchetKey;
+    this.identityKey      = identityKey;
+
+    byte[]  version = {ByteUtil.intsToByteHighAndLow(this.version, this.supportedVersion)};
+    Builder builder = WhisperProtos.KeyExchangeMessage
+                                   .newBuilder()
+                                   .setId((sequence << 5) | flags)
+                                   .setBaseKey(ByteString.copyFrom(baseKey.serialize()))
+                                   .setRatchetKey(ByteString.copyFrom(ratchetKey.serialize()))
+                                   .setIdentityKey(ByteString.copyFrom(identityKey.serialize()));
+
+    if (messageVersion >= 3) {
+      builder.setBaseKeySignature(ByteString.copyFrom(baseKeySignature));
+    }
+
+    this.serialized = ByteUtil.combine(version, builder.build().toByteArray());
+  }
+
+  public KeyExchangeMessage(byte[] serialized)
+      throws InvalidMessageException, InvalidVersionException, LegacyMessageException
+  {
+    try {
+      byte[][] parts        = ByteUtil.split(serialized, 1, serialized.length - 1);
+      this.version          = ByteUtil.highBitsToInt(parts[0][0]);
+      this.supportedVersion = ByteUtil.lowBitsToInt(parts[0][0]);
+
+      if (this.version <= CiphertextMessage.UNSUPPORTED_VERSION) {
+        throw new LegacyMessageException("Unsupported legacy version: " + this.version);
+      }
+
+      if (this.version > CiphertextMessage.CURRENT_VERSION) {
+        throw new InvalidVersionException("Unknown version: " + this.version);
+      }
+
+      WhisperProtos.KeyExchangeMessage message = WhisperProtos.KeyExchangeMessage.parseFrom(parts[1]);
+
+      if (!message.hasId()           || !message.hasBaseKey()     ||
+          !message.hasRatchetKey()   || !message.hasIdentityKey() ||
+          (this.version >=3 && !message.hasBaseKeySignature()))
+      {
+        throw new InvalidMessageException("Some required fields missing!");
+      }
+
+      this.sequence         = message.getId() >> 5;
+      this.flags            = message.getId() & 0x1f;
+      this.serialized       = serialized;
+      this.baseKey          = Curve.decodePoint(message.getBaseKey().toByteArray(), 0);
+      this.baseKeySignature = message.getBaseKeySignature().toByteArray();
+      this.ratchetKey       = Curve.decodePoint(message.getRatchetKey().toByteArray(), 0);
+      this.identityKey      = new IdentityKey(message.getIdentityKey().toByteArray(), 0);
+    } catch (InvalidKeyException | IOException e) {
+      throw new InvalidMessageException(e);
+    }
+  }
+
+  public int getVersion() {
+    return version;
+  }
+
+  public ECPublicKey getBaseKey() {
+    return baseKey;
+  }
+
+  public byte[] getBaseKeySignature() {
+    return baseKeySignature;
+  }
+
+  public ECPublicKey getRatchetKey() {
+    return ratchetKey;
+  }
+
+  public IdentityKey getIdentityKey() {
+    return identityKey;
+  }
+
+  public boolean hasIdentityKey() {
+    return true;
+  }
+
+  public int getMaxVersion() {
+    return supportedVersion;
+  }
+
+  public boolean isResponse() {
+    return ((flags & RESPONSE_FLAG) != 0);
+  }
+
+  public boolean isInitiate() {
+    return (flags & INITIATE_FLAG) != 0;
+  }
+
+  public boolean isResponseForSimultaneousInitiate() {
+    return (flags & SIMULTAENOUS_INITIATE_FLAG) != 0;
+  }
+
+  public int getFlags() {
+    return flags;
+  }
+
+  public int getSequence() {
+    return sequence;
+  }
+
+  public byte[] serialize() {
+    return serialized;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/protocol/PreKeyWhisperMessage.java b/src/main/java/org/whispersystems/libaxolotl/protocol/PreKeyWhisperMessage.java
new file mode 100644
index 00000000..fff6d02a
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/protocol/PreKeyWhisperMessage.java
@@ -0,0 +1,147 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.protocol;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.InvalidMessageException;
+import org.whispersystems.libaxolotl.InvalidVersionException;
+import org.whispersystems.libaxolotl.LegacyMessageException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.util.ByteUtil;
+import org.whispersystems.libaxolotl.util.guava.Optional;
+
+
+public class PreKeyWhisperMessage implements CiphertextMessage {
+
+  private final int               version;
+  private final int               registrationId;
+  private final Optional<Integer> preKeyId;
+  private final int               signedPreKeyId;
+  private final ECPublicKey       baseKey;
+  private final IdentityKey       identityKey;
+  private final WhisperMessage    message;
+  private final byte[]            serialized;
+
+  public PreKeyWhisperMessage(byte[] serialized)
+      throws InvalidMessageException, InvalidVersionException
+  {
+    try {
+      this.version = ByteUtil.highBitsToInt(serialized[0]);
+
+      if (this.version > CiphertextMessage.CURRENT_VERSION) {
+        throw new InvalidVersionException("Unknown version: " + this.version);
+      }
+
+      WhisperProtos.PreKeyWhisperMessage preKeyWhisperMessage
+          = WhisperProtos.PreKeyWhisperMessage.parseFrom(ByteString.copyFrom(serialized, 1,
+                                                                             serialized.length-1));
+
+      if ((version == 2 && !preKeyWhisperMessage.hasPreKeyId())        ||
+          (version == 3 && !preKeyWhisperMessage.hasSignedPreKeyId())  ||
+          !preKeyWhisperMessage.hasBaseKey()                           ||
+          !preKeyWhisperMessage.hasIdentityKey()                       ||
+          !preKeyWhisperMessage.hasMessage())
+      {
+        throw new InvalidMessageException("Incomplete message.");
+      }
+
+      this.serialized     = serialized;
+      this.registrationId = preKeyWhisperMessage.getRegistrationId();
+      this.preKeyId       = preKeyWhisperMessage.hasPreKeyId() ? Optional.of(preKeyWhisperMessage.getPreKeyId()) : Optional.<Integer>absent();
+      this.signedPreKeyId = preKeyWhisperMessage.hasSignedPreKeyId() ? preKeyWhisperMessage.getSignedPreKeyId() : -1;
+      this.baseKey        = Curve.decodePoint(preKeyWhisperMessage.getBaseKey().toByteArray(), 0);
+      this.identityKey    = new IdentityKey(Curve.decodePoint(preKeyWhisperMessage.getIdentityKey().toByteArray(), 0));
+      this.message        = new WhisperMessage(preKeyWhisperMessage.getMessage().toByteArray());
+    } catch (InvalidProtocolBufferException | InvalidKeyException | LegacyMessageException e) {
+      throw new InvalidMessageException(e);
+    }
+  }
+
+  public PreKeyWhisperMessage(int messageVersion, int registrationId, Optional<Integer> preKeyId,
+                              int signedPreKeyId, ECPublicKey baseKey, IdentityKey identityKey,
+                              WhisperMessage message)
+  {
+    this.version        = messageVersion;
+    this.registrationId = registrationId;
+    this.preKeyId       = preKeyId;
+    this.signedPreKeyId = signedPreKeyId;
+    this.baseKey        = baseKey;
+    this.identityKey    = identityKey;
+    this.message        = message;
+
+    WhisperProtos.PreKeyWhisperMessage.Builder builder =
+        WhisperProtos.PreKeyWhisperMessage.newBuilder()
+                                          .setSignedPreKeyId(signedPreKeyId)
+                                          .setBaseKey(ByteString.copyFrom(baseKey.serialize()))
+                                          .setIdentityKey(ByteString.copyFrom(identityKey.serialize()))
+                                          .setMessage(ByteString.copyFrom(message.serialize()))
+                                          .setRegistrationId(registrationId);
+
+    if (preKeyId.isPresent()) {
+      builder.setPreKeyId(preKeyId.get());
+    }
+
+    byte[] versionBytes = {ByteUtil.intsToByteHighAndLow(this.version, CURRENT_VERSION)};
+    byte[] messageBytes = builder.build().toByteArray();
+
+    this.serialized = ByteUtil.combine(versionBytes, messageBytes);
+  }
+
+  public int getMessageVersion() {
+    return version;
+  }
+
+  public IdentityKey getIdentityKey() {
+    return identityKey;
+  }
+
+  public int getRegistrationId() {
+    return registrationId;
+  }
+
+  public Optional<Integer> getPreKeyId() {
+    return preKeyId;
+  }
+
+  public int getSignedPreKeyId() {
+    return signedPreKeyId;
+  }
+
+  public ECPublicKey getBaseKey() {
+    return baseKey;
+  }
+
+  public WhisperMessage getWhisperMessage() {
+    return message;
+  }
+
+  @Override
+  public byte[] serialize() {
+    return serialized;
+  }
+
+  @Override
+  public int getType() {
+    return CiphertextMessage.PREKEY_TYPE;
+  }
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/protocol/SenderKeyDistributionMessage.java b/src/main/java/org/whispersystems/libaxolotl/protocol/SenderKeyDistributionMessage.java
new file mode 100644
index 00000000..424dd87c
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/protocol/SenderKeyDistributionMessage.java
@@ -0,0 +1,56 @@
+package org.whispersystems.libaxolotl.protocol;
+
+import com.google.protobuf.ByteString;
+
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.util.ByteUtil;
+
+public class SenderKeyDistributionMessage implements CiphertextMessage {
+
+  private final int         id;
+  private final int         iteration;
+  private final byte[]      chainKey;
+  private final ECPublicKey signatureKey;
+  private final byte[]      serialized;
+
+  public SenderKeyDistributionMessage(int id, int iteration, byte[] chainKey, ECPublicKey signatureKey) {
+    byte[] version = {ByteUtil.intsToByteHighAndLow(CURRENT_VERSION, CURRENT_VERSION)};
+
+    this.id           = id;
+    this.iteration    = iteration;
+    this.chainKey     = chainKey;
+    this.signatureKey = signatureKey;
+    this.serialized   = WhisperProtos.SenderKeyDistributionMessage.newBuilder()
+                                                                  .setId(id)
+                                                                  .setIteration(iteration)
+                                                                  .setChainKey(ByteString.copyFrom(chainKey))
+                                                                  .setSigningKey(ByteString.copyFrom(signatureKey.serialize()))
+                                                                  .build().toByteArray();
+  }
+
+  @Override
+  public byte[] serialize() {
+    return serialized;
+  }
+
+  @Override
+  public int getType() {
+    return SENDERKEY_DISTRIBUTION_TYPE;
+  }
+
+  public int getIteration() {
+    return iteration;
+  }
+
+  public byte[] getChainKey() {
+    return chainKey;
+  }
+
+  public ECPublicKey getSignatureKey() {
+    return signatureKey;
+  }
+
+  public int getId() {
+    return id;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/protocol/SenderKeyMessage.java b/src/main/java/org/whispersystems/libaxolotl/protocol/SenderKeyMessage.java
new file mode 100644
index 00000000..b3a17456
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/protocol/SenderKeyMessage.java
@@ -0,0 +1,121 @@
+package org.whispersystems.libaxolotl.protocol;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.InvalidMessageException;
+import org.whispersystems.libaxolotl.LegacyMessageException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECPrivateKey;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.util.ByteUtil;
+
+import java.text.ParseException;
+
+public class SenderKeyMessage implements CiphertextMessage {
+
+  private static final int SIGNATURE_LENGTH = 64;
+
+  private final int         messageVersion;
+  private final int         keyId;
+  private final int         iteration;
+  private final byte[]      ciphertext;
+  private final byte[]      serialized;
+
+  public SenderKeyMessage(byte[] serialized) throws InvalidMessageException, LegacyMessageException {
+    try {
+      byte[][] messageParts = ByteUtil.split(serialized, 1, serialized.length - 1 - SIGNATURE_LENGTH, SIGNATURE_LENGTH);
+      byte     version      = messageParts[0][0];
+      byte[]   message      = messageParts[1];
+      byte[]   signature    = messageParts[2];
+
+      if (ByteUtil.highBitsToInt(version) < 3) {
+        throw new LegacyMessageException("Legacy message: " + ByteUtil.highBitsToInt(version));
+      }
+
+      if (ByteUtil.highBitsToInt(version) > CURRENT_VERSION) {
+        throw new InvalidMessageException("Unknown version: " + ByteUtil.highBitsToInt(version));
+      }
+
+      WhisperProtos.SenderKeyMessage senderKeyMessage = WhisperProtos.SenderKeyMessage.parseFrom(message);
+
+      if (!senderKeyMessage.hasId() ||
+          !senderKeyMessage.hasIteration() ||
+          !senderKeyMessage.hasCiphertext())
+      {
+        throw new InvalidMessageException("Incomplete message.");
+      }
+
+      this.serialized     = serialized;
+      this.messageVersion = ByteUtil.highBitsToInt(version);
+      this.keyId          = senderKeyMessage.getId();
+      this.iteration      = senderKeyMessage.getIteration();
+      this.ciphertext     = senderKeyMessage.getCiphertext().toByteArray();
+    } catch (InvalidProtocolBufferException | ParseException e) {
+      throw new InvalidMessageException(e);
+    }
+  }
+
+  public SenderKeyMessage(int keyId, int iteration, byte[] ciphertext, ECPrivateKey signatureKey) {
+    byte[] version = {ByteUtil.intsToByteHighAndLow(CURRENT_VERSION, CURRENT_VERSION)};
+    byte[] message = WhisperProtos.SenderKeyMessage.newBuilder()
+                                                   .setId(keyId)
+                                                   .setIteration(iteration)
+                                                   .setCiphertext(ByteString.copyFrom(ciphertext))
+                                                   .build().toByteArray();
+
+    byte[] signature = getSignature(signatureKey, ByteUtil.combine(version, message));
+
+    this.serialized       = ByteUtil.combine(version, message, signature);
+    this.messageVersion   = CURRENT_VERSION;
+    this.keyId            = keyId;
+    this.iteration        = iteration;
+    this.ciphertext       = ciphertext;
+  }
+
+  public int getKeyId() {
+    return keyId;
+  }
+
+  public int getIteration() {
+    return iteration;
+  }
+
+  public byte[] getCipherText() {
+    return ciphertext;
+  }
+
+  public void verifySignature(ECPublicKey signatureKey)
+      throws InvalidMessageException
+  {
+    try {
+      byte[][] parts    = ByteUtil.split(serialized, serialized.length - SIGNATURE_LENGTH, SIGNATURE_LENGTH);
+
+      if (!Curve.verifySignature(signatureKey, parts[0], parts[1])) {
+        throw new InvalidMessageException("Invalid signature!");
+      }
+
+    } catch (InvalidKeyException e) {
+      throw new InvalidMessageException(e);
+    }
+  }
+
+  private byte[] getSignature(ECPrivateKey signatureKey, byte[] serialized) {
+    try {
+      return Curve.calculateSignature(signatureKey, serialized);
+    } catch (InvalidKeyException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  @Override
+  public byte[] serialize() {
+    return serialized;
+  }
+
+  @Override
+  public int getType() {
+    return CiphertextMessage.SENDERKEY_TYPE;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/protocol/WhisperMessage.java b/src/main/java/org/whispersystems/libaxolotl/protocol/WhisperMessage.java
new file mode 100644
index 00000000..980bec1f
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/protocol/WhisperMessage.java
@@ -0,0 +1,172 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.protocol;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.InvalidMessageException;
+import org.whispersystems.libaxolotl.LegacyMessageException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.util.ByteUtil;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.text.ParseException;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+
+public class WhisperMessage implements CiphertextMessage {
+
+  private static final int MAC_LENGTH = 8;
+
+  private final int         messageVersion;
+  private final ECPublicKey senderRatchetKey;
+  private final int         counter;
+  private final int         previousCounter;
+  private final byte[]      ciphertext;
+  private final byte[]      serialized;
+
+  public WhisperMessage(byte[] serialized) throws InvalidMessageException, LegacyMessageException {
+    try {
+      byte[][] messageParts = ByteUtil.split(serialized, 1, serialized.length - 1 - MAC_LENGTH, MAC_LENGTH);
+      byte     version      = messageParts[0][0];
+      byte[]   message      = messageParts[1];
+      byte[]   mac          = messageParts[2];
+
+      if (ByteUtil.highBitsToInt(version) <= CiphertextMessage.UNSUPPORTED_VERSION) {
+        throw new LegacyMessageException("Legacy message: " + ByteUtil.highBitsToInt(version));
+      }
+
+      if (ByteUtil.highBitsToInt(version) > CURRENT_VERSION) {
+        throw new InvalidMessageException("Unknown version: " + ByteUtil.highBitsToInt(version));
+      }
+
+      WhisperProtos.WhisperMessage whisperMessage = WhisperProtos.WhisperMessage.parseFrom(message);
+
+      if (!whisperMessage.hasCiphertext() ||
+          !whisperMessage.hasCounter() ||
+          !whisperMessage.hasRatchetKey())
+      {
+        throw new InvalidMessageException("Incomplete message.");
+      }
+
+      this.serialized       = serialized;
+      this.senderRatchetKey = Curve.decodePoint(whisperMessage.getRatchetKey().toByteArray(), 0);
+      this.messageVersion   = ByteUtil.highBitsToInt(version);
+      this.counter          = whisperMessage.getCounter();
+      this.previousCounter  = whisperMessage.getPreviousCounter();
+      this.ciphertext       = whisperMessage.getCiphertext().toByteArray();
+    } catch (InvalidProtocolBufferException | InvalidKeyException | ParseException e) {
+      throw new InvalidMessageException(e);
+    }
+  }
+
+  public WhisperMessage(int messageVersion, SecretKeySpec macKey, ECPublicKey senderRatchetKey,
+                        int counter, int previousCounter, byte[] ciphertext,
+                        IdentityKey senderIdentityKey,
+                        IdentityKey receiverIdentityKey)
+  {
+    byte[] version = {ByteUtil.intsToByteHighAndLow(messageVersion, CURRENT_VERSION)};
+    byte[] message = WhisperProtos.WhisperMessage.newBuilder()
+                                   .setRatchetKey(ByteString.copyFrom(senderRatchetKey.serialize()))
+                                   .setCounter(counter)
+                                   .setPreviousCounter(previousCounter)
+                                   .setCiphertext(ByteString.copyFrom(ciphertext))
+                                   .build().toByteArray();
+
+    byte[] mac     = getMac(messageVersion, senderIdentityKey, receiverIdentityKey, macKey,
+                            ByteUtil.combine(version, message));
+
+    this.serialized       = ByteUtil.combine(version, message, mac);
+    this.senderRatchetKey = senderRatchetKey;
+    this.counter          = counter;
+    this.previousCounter  = previousCounter;
+    this.ciphertext       = ciphertext;
+    this.messageVersion   = messageVersion;
+  }
+
+  public ECPublicKey getSenderRatchetKey()  {
+    return senderRatchetKey;
+  }
+
+  public int getMessageVersion() {
+    return messageVersion;
+  }
+
+  public int getCounter() {
+    return counter;
+  }
+
+  public byte[] getBody() {
+    return ciphertext;
+  }
+
+  public void verifyMac(int messageVersion, IdentityKey senderIdentityKey,
+                        IdentityKey receiverIdentityKey, SecretKeySpec macKey)
+      throws InvalidMessageException
+  {
+    byte[][] parts    = ByteUtil.split(serialized, serialized.length - MAC_LENGTH, MAC_LENGTH);
+    byte[]   ourMac   = getMac(messageVersion, senderIdentityKey, receiverIdentityKey, macKey, parts[0]);
+    byte[]   theirMac = parts[1];
+
+    if (!MessageDigest.isEqual(ourMac, theirMac)) {
+      throw new InvalidMessageException("Bad Mac!");
+    }
+  }
+
+  private byte[] getMac(int messageVersion,
+                        IdentityKey senderIdentityKey,
+                        IdentityKey receiverIdentityKey,
+                        SecretKeySpec macKey, byte[] serialized)
+  {
+    try {
+      Mac mac = Mac.getInstance("HmacSHA256");
+      mac.init(macKey);
+
+      if (messageVersion >= 3) {
+        mac.update(senderIdentityKey.getPublicKey().serialize());
+        mac.update(receiverIdentityKey.getPublicKey().serialize());
+      }
+
+      byte[] fullMac = mac.doFinal(serialized);
+      return ByteUtil.trim(fullMac, MAC_LENGTH);
+    } catch (NoSuchAlgorithmException | java.security.InvalidKeyException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  @Override
+  public byte[] serialize() {
+    return serialized;
+  }
+
+  @Override
+  public int getType() {
+    return CiphertextMessage.WHISPER_TYPE;
+  }
+
+  public static boolean isLegacy(byte[] message) {
+    return message != null && message.length >= 1 &&
+        ByteUtil.highBitsToInt(message[0]) <= CiphertextMessage.UNSUPPORTED_VERSION;
+  }
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/protocol/WhisperProtos.java b/src/main/java/org/whispersystems/libaxolotl/protocol/WhisperProtos.java
new file mode 100644
index 00000000..12ab0272
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/protocol/WhisperProtos.java
@@ -0,0 +1,3532 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: WhisperTextProtocol.proto
+
+package org.whispersystems.libaxolotl.protocol;
+
+public final class WhisperProtos {
+  private WhisperProtos() {}
+  public static void registerAllExtensions(
+      com.google.protobuf.ExtensionRegistry registry) {
+  }
+  public interface WhisperMessageOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional bytes ratchetKey = 1;
+    /**
+     * <code>optional bytes ratchetKey = 1;</code>
+     */
+    boolean hasRatchetKey();
+    /**
+     * <code>optional bytes ratchetKey = 1;</code>
+     */
+    com.google.protobuf.ByteString getRatchetKey();
+
+    // optional uint32 counter = 2;
+    /**
+     * <code>optional uint32 counter = 2;</code>
+     */
+    boolean hasCounter();
+    /**
+     * <code>optional uint32 counter = 2;</code>
+     */
+    int getCounter();
+
+    // optional uint32 previousCounter = 3;
+    /**
+     * <code>optional uint32 previousCounter = 3;</code>
+     */
+    boolean hasPreviousCounter();
+    /**
+     * <code>optional uint32 previousCounter = 3;</code>
+     */
+    int getPreviousCounter();
+
+    // optional bytes ciphertext = 4;
+    /**
+     * <code>optional bytes ciphertext = 4;</code>
+     */
+    boolean hasCiphertext();
+    /**
+     * <code>optional bytes ciphertext = 4;</code>
+     */
+    com.google.protobuf.ByteString getCiphertext();
+  }
+  /**
+   * Protobuf type {@code textsecure.WhisperMessage}
+   */
+  public static final class WhisperMessage extends
+      com.google.protobuf.GeneratedMessage
+      implements WhisperMessageOrBuilder {
+    // Use WhisperMessage.newBuilder() to construct.
+    private WhisperMessage(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private WhisperMessage(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final WhisperMessage defaultInstance;
+    public static WhisperMessage getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public WhisperMessage getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private WhisperMessage(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 10: {
+              bitField0_ |= 0x00000001;
+              ratchetKey_ = input.readBytes();
+              break;
+            }
+            case 16: {
+              bitField0_ |= 0x00000002;
+              counter_ = input.readUInt32();
+              break;
+            }
+            case 24: {
+              bitField0_ |= 0x00000004;
+              previousCounter_ = input.readUInt32();
+              break;
+            }
+            case 34: {
+              bitField0_ |= 0x00000008;
+              ciphertext_ = input.readBytes();
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_WhisperMessage_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_WhisperMessage_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage.class, org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<WhisperMessage> PARSER =
+        new com.google.protobuf.AbstractParser<WhisperMessage>() {
+      public WhisperMessage parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new WhisperMessage(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<WhisperMessage> getParserForType() {
+      return PARSER;
+    }
+
+    private int bitField0_;
+    // optional bytes ratchetKey = 1;
+    public static final int RATCHETKEY_FIELD_NUMBER = 1;
+    private com.google.protobuf.ByteString ratchetKey_;
+    /**
+     * <code>optional bytes ratchetKey = 1;</code>
+     */
+    public boolean hasRatchetKey() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional bytes ratchetKey = 1;</code>
+     */
+    public com.google.protobuf.ByteString getRatchetKey() {
+      return ratchetKey_;
+    }
+
+    // optional uint32 counter = 2;
+    public static final int COUNTER_FIELD_NUMBER = 2;
+    private int counter_;
+    /**
+     * <code>optional uint32 counter = 2;</code>
+     */
+    public boolean hasCounter() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>optional uint32 counter = 2;</code>
+     */
+    public int getCounter() {
+      return counter_;
+    }
+
+    // optional uint32 previousCounter = 3;
+    public static final int PREVIOUSCOUNTER_FIELD_NUMBER = 3;
+    private int previousCounter_;
+    /**
+     * <code>optional uint32 previousCounter = 3;</code>
+     */
+    public boolean hasPreviousCounter() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>optional uint32 previousCounter = 3;</code>
+     */
+    public int getPreviousCounter() {
+      return previousCounter_;
+    }
+
+    // optional bytes ciphertext = 4;
+    public static final int CIPHERTEXT_FIELD_NUMBER = 4;
+    private com.google.protobuf.ByteString ciphertext_;
+    /**
+     * <code>optional bytes ciphertext = 4;</code>
+     */
+    public boolean hasCiphertext() {
+      return ((bitField0_ & 0x00000008) == 0x00000008);
+    }
+    /**
+     * <code>optional bytes ciphertext = 4;</code>
+     */
+    public com.google.protobuf.ByteString getCiphertext() {
+      return ciphertext_;
+    }
+
+    private void initFields() {
+      ratchetKey_ = com.google.protobuf.ByteString.EMPTY;
+      counter_ = 0;
+      previousCounter_ = 0;
+      ciphertext_ = com.google.protobuf.ByteString.EMPTY;
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeBytes(1, ratchetKey_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeUInt32(2, counter_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeUInt32(3, previousCounter_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        output.writeBytes(4, ciphertext_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(1, ratchetKey_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(2, counter_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(3, previousCounter_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(4, ciphertext_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.WhisperMessage}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessageOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_WhisperMessage_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_WhisperMessage_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage.class, org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        ratchetKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        counter_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000002);
+        previousCounter_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000004);
+        ciphertext_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000008);
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_WhisperMessage_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage build() {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage buildPartial() {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage result = new org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.ratchetKey_ = ratchetKey_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        result.counter_ = counter_;
+        if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        result.previousCounter_ = previousCounter_;
+        if (((from_bitField0_ & 0x00000008) == 0x00000008)) {
+          to_bitField0_ |= 0x00000008;
+        }
+        result.ciphertext_ = ciphertext_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage) {
+          return mergeFrom((org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage other) {
+        if (other == org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage.getDefaultInstance()) return this;
+        if (other.hasRatchetKey()) {
+          setRatchetKey(other.getRatchetKey());
+        }
+        if (other.hasCounter()) {
+          setCounter(other.getCounter());
+        }
+        if (other.hasPreviousCounter()) {
+          setPreviousCounter(other.getPreviousCounter());
+        }
+        if (other.hasCiphertext()) {
+          setCiphertext(other.getCiphertext());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.protocol.WhisperProtos.WhisperMessage) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional bytes ratchetKey = 1;
+      private com.google.protobuf.ByteString ratchetKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes ratchetKey = 1;</code>
+       */
+      public boolean hasRatchetKey() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional bytes ratchetKey = 1;</code>
+       */
+      public com.google.protobuf.ByteString getRatchetKey() {
+        return ratchetKey_;
+      }
+      /**
+       * <code>optional bytes ratchetKey = 1;</code>
+       */
+      public Builder setRatchetKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000001;
+        ratchetKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes ratchetKey = 1;</code>
+       */
+      public Builder clearRatchetKey() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        ratchetKey_ = getDefaultInstance().getRatchetKey();
+        onChanged();
+        return this;
+      }
+
+      // optional uint32 counter = 2;
+      private int counter_ ;
+      /**
+       * <code>optional uint32 counter = 2;</code>
+       */
+      public boolean hasCounter() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional uint32 counter = 2;</code>
+       */
+      public int getCounter() {
+        return counter_;
+      }
+      /**
+       * <code>optional uint32 counter = 2;</code>
+       */
+      public Builder setCounter(int value) {
+        bitField0_ |= 0x00000002;
+        counter_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 counter = 2;</code>
+       */
+      public Builder clearCounter() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        counter_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional uint32 previousCounter = 3;
+      private int previousCounter_ ;
+      /**
+       * <code>optional uint32 previousCounter = 3;</code>
+       */
+      public boolean hasPreviousCounter() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional uint32 previousCounter = 3;</code>
+       */
+      public int getPreviousCounter() {
+        return previousCounter_;
+      }
+      /**
+       * <code>optional uint32 previousCounter = 3;</code>
+       */
+      public Builder setPreviousCounter(int value) {
+        bitField0_ |= 0x00000004;
+        previousCounter_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 previousCounter = 3;</code>
+       */
+      public Builder clearPreviousCounter() {
+        bitField0_ = (bitField0_ & ~0x00000004);
+        previousCounter_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional bytes ciphertext = 4;
+      private com.google.protobuf.ByteString ciphertext_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes ciphertext = 4;</code>
+       */
+      public boolean hasCiphertext() {
+        return ((bitField0_ & 0x00000008) == 0x00000008);
+      }
+      /**
+       * <code>optional bytes ciphertext = 4;</code>
+       */
+      public com.google.protobuf.ByteString getCiphertext() {
+        return ciphertext_;
+      }
+      /**
+       * <code>optional bytes ciphertext = 4;</code>
+       */
+      public Builder setCiphertext(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000008;
+        ciphertext_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes ciphertext = 4;</code>
+       */
+      public Builder clearCiphertext() {
+        bitField0_ = (bitField0_ & ~0x00000008);
+        ciphertext_ = getDefaultInstance().getCiphertext();
+        onChanged();
+        return this;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.WhisperMessage)
+    }
+
+    static {
+      defaultInstance = new WhisperMessage(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.WhisperMessage)
+  }
+
+  public interface PreKeyWhisperMessageOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional uint32 registrationId = 5;
+    /**
+     * <code>optional uint32 registrationId = 5;</code>
+     */
+    boolean hasRegistrationId();
+    /**
+     * <code>optional uint32 registrationId = 5;</code>
+     */
+    int getRegistrationId();
+
+    // optional uint32 preKeyId = 1;
+    /**
+     * <code>optional uint32 preKeyId = 1;</code>
+     */
+    boolean hasPreKeyId();
+    /**
+     * <code>optional uint32 preKeyId = 1;</code>
+     */
+    int getPreKeyId();
+
+    // optional uint32 signedPreKeyId = 6;
+    /**
+     * <code>optional uint32 signedPreKeyId = 6;</code>
+     */
+    boolean hasSignedPreKeyId();
+    /**
+     * <code>optional uint32 signedPreKeyId = 6;</code>
+     */
+    int getSignedPreKeyId();
+
+    // optional bytes baseKey = 2;
+    /**
+     * <code>optional bytes baseKey = 2;</code>
+     */
+    boolean hasBaseKey();
+    /**
+     * <code>optional bytes baseKey = 2;</code>
+     */
+    com.google.protobuf.ByteString getBaseKey();
+
+    // optional bytes identityKey = 3;
+    /**
+     * <code>optional bytes identityKey = 3;</code>
+     */
+    boolean hasIdentityKey();
+    /**
+     * <code>optional bytes identityKey = 3;</code>
+     */
+    com.google.protobuf.ByteString getIdentityKey();
+
+    // optional bytes message = 4;
+    /**
+     * <code>optional bytes message = 4;</code>
+     *
+     * <pre>
+     * WhisperMessage
+     * </pre>
+     */
+    boolean hasMessage();
+    /**
+     * <code>optional bytes message = 4;</code>
+     *
+     * <pre>
+     * WhisperMessage
+     * </pre>
+     */
+    com.google.protobuf.ByteString getMessage();
+  }
+  /**
+   * Protobuf type {@code textsecure.PreKeyWhisperMessage}
+   */
+  public static final class PreKeyWhisperMessage extends
+      com.google.protobuf.GeneratedMessage
+      implements PreKeyWhisperMessageOrBuilder {
+    // Use PreKeyWhisperMessage.newBuilder() to construct.
+    private PreKeyWhisperMessage(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private PreKeyWhisperMessage(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final PreKeyWhisperMessage defaultInstance;
+    public static PreKeyWhisperMessage getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public PreKeyWhisperMessage getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private PreKeyWhisperMessage(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 8: {
+              bitField0_ |= 0x00000002;
+              preKeyId_ = input.readUInt32();
+              break;
+            }
+            case 18: {
+              bitField0_ |= 0x00000008;
+              baseKey_ = input.readBytes();
+              break;
+            }
+            case 26: {
+              bitField0_ |= 0x00000010;
+              identityKey_ = input.readBytes();
+              break;
+            }
+            case 34: {
+              bitField0_ |= 0x00000020;
+              message_ = input.readBytes();
+              break;
+            }
+            case 40: {
+              bitField0_ |= 0x00000001;
+              registrationId_ = input.readUInt32();
+              break;
+            }
+            case 48: {
+              bitField0_ |= 0x00000004;
+              signedPreKeyId_ = input.readUInt32();
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_PreKeyWhisperMessage_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_PreKeyWhisperMessage_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage.class, org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<PreKeyWhisperMessage> PARSER =
+        new com.google.protobuf.AbstractParser<PreKeyWhisperMessage>() {
+      public PreKeyWhisperMessage parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new PreKeyWhisperMessage(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<PreKeyWhisperMessage> getParserForType() {
+      return PARSER;
+    }
+
+    private int bitField0_;
+    // optional uint32 registrationId = 5;
+    public static final int REGISTRATIONID_FIELD_NUMBER = 5;
+    private int registrationId_;
+    /**
+     * <code>optional uint32 registrationId = 5;</code>
+     */
+    public boolean hasRegistrationId() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional uint32 registrationId = 5;</code>
+     */
+    public int getRegistrationId() {
+      return registrationId_;
+    }
+
+    // optional uint32 preKeyId = 1;
+    public static final int PREKEYID_FIELD_NUMBER = 1;
+    private int preKeyId_;
+    /**
+     * <code>optional uint32 preKeyId = 1;</code>
+     */
+    public boolean hasPreKeyId() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>optional uint32 preKeyId = 1;</code>
+     */
+    public int getPreKeyId() {
+      return preKeyId_;
+    }
+
+    // optional uint32 signedPreKeyId = 6;
+    public static final int SIGNEDPREKEYID_FIELD_NUMBER = 6;
+    private int signedPreKeyId_;
+    /**
+     * <code>optional uint32 signedPreKeyId = 6;</code>
+     */
+    public boolean hasSignedPreKeyId() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>optional uint32 signedPreKeyId = 6;</code>
+     */
+    public int getSignedPreKeyId() {
+      return signedPreKeyId_;
+    }
+
+    // optional bytes baseKey = 2;
+    public static final int BASEKEY_FIELD_NUMBER = 2;
+    private com.google.protobuf.ByteString baseKey_;
+    /**
+     * <code>optional bytes baseKey = 2;</code>
+     */
+    public boolean hasBaseKey() {
+      return ((bitField0_ & 0x00000008) == 0x00000008);
+    }
+    /**
+     * <code>optional bytes baseKey = 2;</code>
+     */
+    public com.google.protobuf.ByteString getBaseKey() {
+      return baseKey_;
+    }
+
+    // optional bytes identityKey = 3;
+    public static final int IDENTITYKEY_FIELD_NUMBER = 3;
+    private com.google.protobuf.ByteString identityKey_;
+    /**
+     * <code>optional bytes identityKey = 3;</code>
+     */
+    public boolean hasIdentityKey() {
+      return ((bitField0_ & 0x00000010) == 0x00000010);
+    }
+    /**
+     * <code>optional bytes identityKey = 3;</code>
+     */
+    public com.google.protobuf.ByteString getIdentityKey() {
+      return identityKey_;
+    }
+
+    // optional bytes message = 4;
+    public static final int MESSAGE_FIELD_NUMBER = 4;
+    private com.google.protobuf.ByteString message_;
+    /**
+     * <code>optional bytes message = 4;</code>
+     *
+     * <pre>
+     * WhisperMessage
+     * </pre>
+     */
+    public boolean hasMessage() {
+      return ((bitField0_ & 0x00000020) == 0x00000020);
+    }
+    /**
+     * <code>optional bytes message = 4;</code>
+     *
+     * <pre>
+     * WhisperMessage
+     * </pre>
+     */
+    public com.google.protobuf.ByteString getMessage() {
+      return message_;
+    }
+
+    private void initFields() {
+      registrationId_ = 0;
+      preKeyId_ = 0;
+      signedPreKeyId_ = 0;
+      baseKey_ = com.google.protobuf.ByteString.EMPTY;
+      identityKey_ = com.google.protobuf.ByteString.EMPTY;
+      message_ = com.google.protobuf.ByteString.EMPTY;
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeUInt32(1, preKeyId_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        output.writeBytes(2, baseKey_);
+      }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        output.writeBytes(3, identityKey_);
+      }
+      if (((bitField0_ & 0x00000020) == 0x00000020)) {
+        output.writeBytes(4, message_);
+      }
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeUInt32(5, registrationId_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeUInt32(6, signedPreKeyId_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(1, preKeyId_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(2, baseKey_);
+      }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(3, identityKey_);
+      }
+      if (((bitField0_ & 0x00000020) == 0x00000020)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(4, message_);
+      }
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(5, registrationId_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(6, signedPreKeyId_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.PreKeyWhisperMessage}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessageOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_PreKeyWhisperMessage_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_PreKeyWhisperMessage_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage.class, org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        registrationId_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        preKeyId_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000002);
+        signedPreKeyId_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000004);
+        baseKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000008);
+        identityKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000010);
+        message_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000020);
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_PreKeyWhisperMessage_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage build() {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage buildPartial() {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage result = new org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.registrationId_ = registrationId_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        result.preKeyId_ = preKeyId_;
+        if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        result.signedPreKeyId_ = signedPreKeyId_;
+        if (((from_bitField0_ & 0x00000008) == 0x00000008)) {
+          to_bitField0_ |= 0x00000008;
+        }
+        result.baseKey_ = baseKey_;
+        if (((from_bitField0_ & 0x00000010) == 0x00000010)) {
+          to_bitField0_ |= 0x00000010;
+        }
+        result.identityKey_ = identityKey_;
+        if (((from_bitField0_ & 0x00000020) == 0x00000020)) {
+          to_bitField0_ |= 0x00000020;
+        }
+        result.message_ = message_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage) {
+          return mergeFrom((org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage other) {
+        if (other == org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage.getDefaultInstance()) return this;
+        if (other.hasRegistrationId()) {
+          setRegistrationId(other.getRegistrationId());
+        }
+        if (other.hasPreKeyId()) {
+          setPreKeyId(other.getPreKeyId());
+        }
+        if (other.hasSignedPreKeyId()) {
+          setSignedPreKeyId(other.getSignedPreKeyId());
+        }
+        if (other.hasBaseKey()) {
+          setBaseKey(other.getBaseKey());
+        }
+        if (other.hasIdentityKey()) {
+          setIdentityKey(other.getIdentityKey());
+        }
+        if (other.hasMessage()) {
+          setMessage(other.getMessage());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.protocol.WhisperProtos.PreKeyWhisperMessage) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional uint32 registrationId = 5;
+      private int registrationId_ ;
+      /**
+       * <code>optional uint32 registrationId = 5;</code>
+       */
+      public boolean hasRegistrationId() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional uint32 registrationId = 5;</code>
+       */
+      public int getRegistrationId() {
+        return registrationId_;
+      }
+      /**
+       * <code>optional uint32 registrationId = 5;</code>
+       */
+      public Builder setRegistrationId(int value) {
+        bitField0_ |= 0x00000001;
+        registrationId_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 registrationId = 5;</code>
+       */
+      public Builder clearRegistrationId() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        registrationId_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional uint32 preKeyId = 1;
+      private int preKeyId_ ;
+      /**
+       * <code>optional uint32 preKeyId = 1;</code>
+       */
+      public boolean hasPreKeyId() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional uint32 preKeyId = 1;</code>
+       */
+      public int getPreKeyId() {
+        return preKeyId_;
+      }
+      /**
+       * <code>optional uint32 preKeyId = 1;</code>
+       */
+      public Builder setPreKeyId(int value) {
+        bitField0_ |= 0x00000002;
+        preKeyId_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 preKeyId = 1;</code>
+       */
+      public Builder clearPreKeyId() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        preKeyId_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional uint32 signedPreKeyId = 6;
+      private int signedPreKeyId_ ;
+      /**
+       * <code>optional uint32 signedPreKeyId = 6;</code>
+       */
+      public boolean hasSignedPreKeyId() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional uint32 signedPreKeyId = 6;</code>
+       */
+      public int getSignedPreKeyId() {
+        return signedPreKeyId_;
+      }
+      /**
+       * <code>optional uint32 signedPreKeyId = 6;</code>
+       */
+      public Builder setSignedPreKeyId(int value) {
+        bitField0_ |= 0x00000004;
+        signedPreKeyId_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 signedPreKeyId = 6;</code>
+       */
+      public Builder clearSignedPreKeyId() {
+        bitField0_ = (bitField0_ & ~0x00000004);
+        signedPreKeyId_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional bytes baseKey = 2;
+      private com.google.protobuf.ByteString baseKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      public boolean hasBaseKey() {
+        return ((bitField0_ & 0x00000008) == 0x00000008);
+      }
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      public com.google.protobuf.ByteString getBaseKey() {
+        return baseKey_;
+      }
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      public Builder setBaseKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000008;
+        baseKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      public Builder clearBaseKey() {
+        bitField0_ = (bitField0_ & ~0x00000008);
+        baseKey_ = getDefaultInstance().getBaseKey();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes identityKey = 3;
+      private com.google.protobuf.ByteString identityKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes identityKey = 3;</code>
+       */
+      public boolean hasIdentityKey() {
+        return ((bitField0_ & 0x00000010) == 0x00000010);
+      }
+      /**
+       * <code>optional bytes identityKey = 3;</code>
+       */
+      public com.google.protobuf.ByteString getIdentityKey() {
+        return identityKey_;
+      }
+      /**
+       * <code>optional bytes identityKey = 3;</code>
+       */
+      public Builder setIdentityKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000010;
+        identityKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes identityKey = 3;</code>
+       */
+      public Builder clearIdentityKey() {
+        bitField0_ = (bitField0_ & ~0x00000010);
+        identityKey_ = getDefaultInstance().getIdentityKey();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes message = 4;
+      private com.google.protobuf.ByteString message_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes message = 4;</code>
+       *
+       * <pre>
+       * WhisperMessage
+       * </pre>
+       */
+      public boolean hasMessage() {
+        return ((bitField0_ & 0x00000020) == 0x00000020);
+      }
+      /**
+       * <code>optional bytes message = 4;</code>
+       *
+       * <pre>
+       * WhisperMessage
+       * </pre>
+       */
+      public com.google.protobuf.ByteString getMessage() {
+        return message_;
+      }
+      /**
+       * <code>optional bytes message = 4;</code>
+       *
+       * <pre>
+       * WhisperMessage
+       * </pre>
+       */
+      public Builder setMessage(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000020;
+        message_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes message = 4;</code>
+       *
+       * <pre>
+       * WhisperMessage
+       * </pre>
+       */
+      public Builder clearMessage() {
+        bitField0_ = (bitField0_ & ~0x00000020);
+        message_ = getDefaultInstance().getMessage();
+        onChanged();
+        return this;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.PreKeyWhisperMessage)
+    }
+
+    static {
+      defaultInstance = new PreKeyWhisperMessage(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.PreKeyWhisperMessage)
+  }
+
+  public interface KeyExchangeMessageOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional uint32 id = 1;
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    boolean hasId();
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    int getId();
+
+    // optional bytes baseKey = 2;
+    /**
+     * <code>optional bytes baseKey = 2;</code>
+     */
+    boolean hasBaseKey();
+    /**
+     * <code>optional bytes baseKey = 2;</code>
+     */
+    com.google.protobuf.ByteString getBaseKey();
+
+    // optional bytes ratchetKey = 3;
+    /**
+     * <code>optional bytes ratchetKey = 3;</code>
+     */
+    boolean hasRatchetKey();
+    /**
+     * <code>optional bytes ratchetKey = 3;</code>
+     */
+    com.google.protobuf.ByteString getRatchetKey();
+
+    // optional bytes identityKey = 4;
+    /**
+     * <code>optional bytes identityKey = 4;</code>
+     */
+    boolean hasIdentityKey();
+    /**
+     * <code>optional bytes identityKey = 4;</code>
+     */
+    com.google.protobuf.ByteString getIdentityKey();
+
+    // optional bytes baseKeySignature = 5;
+    /**
+     * <code>optional bytes baseKeySignature = 5;</code>
+     */
+    boolean hasBaseKeySignature();
+    /**
+     * <code>optional bytes baseKeySignature = 5;</code>
+     */
+    com.google.protobuf.ByteString getBaseKeySignature();
+  }
+  /**
+   * Protobuf type {@code textsecure.KeyExchangeMessage}
+   */
+  public static final class KeyExchangeMessage extends
+      com.google.protobuf.GeneratedMessage
+      implements KeyExchangeMessageOrBuilder {
+    // Use KeyExchangeMessage.newBuilder() to construct.
+    private KeyExchangeMessage(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private KeyExchangeMessage(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final KeyExchangeMessage defaultInstance;
+    public static KeyExchangeMessage getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public KeyExchangeMessage getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private KeyExchangeMessage(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 8: {
+              bitField0_ |= 0x00000001;
+              id_ = input.readUInt32();
+              break;
+            }
+            case 18: {
+              bitField0_ |= 0x00000002;
+              baseKey_ = input.readBytes();
+              break;
+            }
+            case 26: {
+              bitField0_ |= 0x00000004;
+              ratchetKey_ = input.readBytes();
+              break;
+            }
+            case 34: {
+              bitField0_ |= 0x00000008;
+              identityKey_ = input.readBytes();
+              break;
+            }
+            case 42: {
+              bitField0_ |= 0x00000010;
+              baseKeySignature_ = input.readBytes();
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_KeyExchangeMessage_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_KeyExchangeMessage_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage.class, org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<KeyExchangeMessage> PARSER =
+        new com.google.protobuf.AbstractParser<KeyExchangeMessage>() {
+      public KeyExchangeMessage parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new KeyExchangeMessage(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<KeyExchangeMessage> getParserForType() {
+      return PARSER;
+    }
+
+    private int bitField0_;
+    // optional uint32 id = 1;
+    public static final int ID_FIELD_NUMBER = 1;
+    private int id_;
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    public boolean hasId() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    public int getId() {
+      return id_;
+    }
+
+    // optional bytes baseKey = 2;
+    public static final int BASEKEY_FIELD_NUMBER = 2;
+    private com.google.protobuf.ByteString baseKey_;
+    /**
+     * <code>optional bytes baseKey = 2;</code>
+     */
+    public boolean hasBaseKey() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>optional bytes baseKey = 2;</code>
+     */
+    public com.google.protobuf.ByteString getBaseKey() {
+      return baseKey_;
+    }
+
+    // optional bytes ratchetKey = 3;
+    public static final int RATCHETKEY_FIELD_NUMBER = 3;
+    private com.google.protobuf.ByteString ratchetKey_;
+    /**
+     * <code>optional bytes ratchetKey = 3;</code>
+     */
+    public boolean hasRatchetKey() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>optional bytes ratchetKey = 3;</code>
+     */
+    public com.google.protobuf.ByteString getRatchetKey() {
+      return ratchetKey_;
+    }
+
+    // optional bytes identityKey = 4;
+    public static final int IDENTITYKEY_FIELD_NUMBER = 4;
+    private com.google.protobuf.ByteString identityKey_;
+    /**
+     * <code>optional bytes identityKey = 4;</code>
+     */
+    public boolean hasIdentityKey() {
+      return ((bitField0_ & 0x00000008) == 0x00000008);
+    }
+    /**
+     * <code>optional bytes identityKey = 4;</code>
+     */
+    public com.google.protobuf.ByteString getIdentityKey() {
+      return identityKey_;
+    }
+
+    // optional bytes baseKeySignature = 5;
+    public static final int BASEKEYSIGNATURE_FIELD_NUMBER = 5;
+    private com.google.protobuf.ByteString baseKeySignature_;
+    /**
+     * <code>optional bytes baseKeySignature = 5;</code>
+     */
+    public boolean hasBaseKeySignature() {
+      return ((bitField0_ & 0x00000010) == 0x00000010);
+    }
+    /**
+     * <code>optional bytes baseKeySignature = 5;</code>
+     */
+    public com.google.protobuf.ByteString getBaseKeySignature() {
+      return baseKeySignature_;
+    }
+
+    private void initFields() {
+      id_ = 0;
+      baseKey_ = com.google.protobuf.ByteString.EMPTY;
+      ratchetKey_ = com.google.protobuf.ByteString.EMPTY;
+      identityKey_ = com.google.protobuf.ByteString.EMPTY;
+      baseKeySignature_ = com.google.protobuf.ByteString.EMPTY;
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeUInt32(1, id_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeBytes(2, baseKey_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeBytes(3, ratchetKey_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        output.writeBytes(4, identityKey_);
+      }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        output.writeBytes(5, baseKeySignature_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(1, id_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(2, baseKey_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(3, ratchetKey_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(4, identityKey_);
+      }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(5, baseKeySignature_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.KeyExchangeMessage}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessageOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_KeyExchangeMessage_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_KeyExchangeMessage_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage.class, org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        id_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        baseKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000002);
+        ratchetKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000004);
+        identityKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000008);
+        baseKeySignature_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000010);
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_KeyExchangeMessage_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage build() {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage buildPartial() {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage result = new org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.id_ = id_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        result.baseKey_ = baseKey_;
+        if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        result.ratchetKey_ = ratchetKey_;
+        if (((from_bitField0_ & 0x00000008) == 0x00000008)) {
+          to_bitField0_ |= 0x00000008;
+        }
+        result.identityKey_ = identityKey_;
+        if (((from_bitField0_ & 0x00000010) == 0x00000010)) {
+          to_bitField0_ |= 0x00000010;
+        }
+        result.baseKeySignature_ = baseKeySignature_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage) {
+          return mergeFrom((org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage other) {
+        if (other == org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage.getDefaultInstance()) return this;
+        if (other.hasId()) {
+          setId(other.getId());
+        }
+        if (other.hasBaseKey()) {
+          setBaseKey(other.getBaseKey());
+        }
+        if (other.hasRatchetKey()) {
+          setRatchetKey(other.getRatchetKey());
+        }
+        if (other.hasIdentityKey()) {
+          setIdentityKey(other.getIdentityKey());
+        }
+        if (other.hasBaseKeySignature()) {
+          setBaseKeySignature(other.getBaseKeySignature());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional uint32 id = 1;
+      private int id_ ;
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public boolean hasId() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public int getId() {
+        return id_;
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public Builder setId(int value) {
+        bitField0_ |= 0x00000001;
+        id_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public Builder clearId() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        id_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional bytes baseKey = 2;
+      private com.google.protobuf.ByteString baseKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      public boolean hasBaseKey() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      public com.google.protobuf.ByteString getBaseKey() {
+        return baseKey_;
+      }
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      public Builder setBaseKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+        baseKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      public Builder clearBaseKey() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        baseKey_ = getDefaultInstance().getBaseKey();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes ratchetKey = 3;
+      private com.google.protobuf.ByteString ratchetKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes ratchetKey = 3;</code>
+       */
+      public boolean hasRatchetKey() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional bytes ratchetKey = 3;</code>
+       */
+      public com.google.protobuf.ByteString getRatchetKey() {
+        return ratchetKey_;
+      }
+      /**
+       * <code>optional bytes ratchetKey = 3;</code>
+       */
+      public Builder setRatchetKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000004;
+        ratchetKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes ratchetKey = 3;</code>
+       */
+      public Builder clearRatchetKey() {
+        bitField0_ = (bitField0_ & ~0x00000004);
+        ratchetKey_ = getDefaultInstance().getRatchetKey();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes identityKey = 4;
+      private com.google.protobuf.ByteString identityKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes identityKey = 4;</code>
+       */
+      public boolean hasIdentityKey() {
+        return ((bitField0_ & 0x00000008) == 0x00000008);
+      }
+      /**
+       * <code>optional bytes identityKey = 4;</code>
+       */
+      public com.google.protobuf.ByteString getIdentityKey() {
+        return identityKey_;
+      }
+      /**
+       * <code>optional bytes identityKey = 4;</code>
+       */
+      public Builder setIdentityKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000008;
+        identityKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes identityKey = 4;</code>
+       */
+      public Builder clearIdentityKey() {
+        bitField0_ = (bitField0_ & ~0x00000008);
+        identityKey_ = getDefaultInstance().getIdentityKey();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes baseKeySignature = 5;
+      private com.google.protobuf.ByteString baseKeySignature_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes baseKeySignature = 5;</code>
+       */
+      public boolean hasBaseKeySignature() {
+        return ((bitField0_ & 0x00000010) == 0x00000010);
+      }
+      /**
+       * <code>optional bytes baseKeySignature = 5;</code>
+       */
+      public com.google.protobuf.ByteString getBaseKeySignature() {
+        return baseKeySignature_;
+      }
+      /**
+       * <code>optional bytes baseKeySignature = 5;</code>
+       */
+      public Builder setBaseKeySignature(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000010;
+        baseKeySignature_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes baseKeySignature = 5;</code>
+       */
+      public Builder clearBaseKeySignature() {
+        bitField0_ = (bitField0_ & ~0x00000010);
+        baseKeySignature_ = getDefaultInstance().getBaseKeySignature();
+        onChanged();
+        return this;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.KeyExchangeMessage)
+    }
+
+    static {
+      defaultInstance = new KeyExchangeMessage(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.KeyExchangeMessage)
+  }
+
+  public interface SenderKeyMessageOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional uint32 id = 1;
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    boolean hasId();
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    int getId();
+
+    // optional uint32 iteration = 2;
+    /**
+     * <code>optional uint32 iteration = 2;</code>
+     */
+    boolean hasIteration();
+    /**
+     * <code>optional uint32 iteration = 2;</code>
+     */
+    int getIteration();
+
+    // optional bytes ciphertext = 3;
+    /**
+     * <code>optional bytes ciphertext = 3;</code>
+     */
+    boolean hasCiphertext();
+    /**
+     * <code>optional bytes ciphertext = 3;</code>
+     */
+    com.google.protobuf.ByteString getCiphertext();
+  }
+  /**
+   * Protobuf type {@code textsecure.SenderKeyMessage}
+   */
+  public static final class SenderKeyMessage extends
+      com.google.protobuf.GeneratedMessage
+      implements SenderKeyMessageOrBuilder {
+    // Use SenderKeyMessage.newBuilder() to construct.
+    private SenderKeyMessage(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private SenderKeyMessage(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final SenderKeyMessage defaultInstance;
+    public static SenderKeyMessage getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public SenderKeyMessage getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private SenderKeyMessage(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 8: {
+              bitField0_ |= 0x00000001;
+              id_ = input.readUInt32();
+              break;
+            }
+            case 16: {
+              bitField0_ |= 0x00000002;
+              iteration_ = input.readUInt32();
+              break;
+            }
+            case 26: {
+              bitField0_ |= 0x00000004;
+              ciphertext_ = input.readBytes();
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_SenderKeyMessage_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_SenderKeyMessage_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage.class, org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<SenderKeyMessage> PARSER =
+        new com.google.protobuf.AbstractParser<SenderKeyMessage>() {
+      public SenderKeyMessage parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new SenderKeyMessage(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<SenderKeyMessage> getParserForType() {
+      return PARSER;
+    }
+
+    private int bitField0_;
+    // optional uint32 id = 1;
+    public static final int ID_FIELD_NUMBER = 1;
+    private int id_;
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    public boolean hasId() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    public int getId() {
+      return id_;
+    }
+
+    // optional uint32 iteration = 2;
+    public static final int ITERATION_FIELD_NUMBER = 2;
+    private int iteration_;
+    /**
+     * <code>optional uint32 iteration = 2;</code>
+     */
+    public boolean hasIteration() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>optional uint32 iteration = 2;</code>
+     */
+    public int getIteration() {
+      return iteration_;
+    }
+
+    // optional bytes ciphertext = 3;
+    public static final int CIPHERTEXT_FIELD_NUMBER = 3;
+    private com.google.protobuf.ByteString ciphertext_;
+    /**
+     * <code>optional bytes ciphertext = 3;</code>
+     */
+    public boolean hasCiphertext() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>optional bytes ciphertext = 3;</code>
+     */
+    public com.google.protobuf.ByteString getCiphertext() {
+      return ciphertext_;
+    }
+
+    private void initFields() {
+      id_ = 0;
+      iteration_ = 0;
+      ciphertext_ = com.google.protobuf.ByteString.EMPTY;
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeUInt32(1, id_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeUInt32(2, iteration_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeBytes(3, ciphertext_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(1, id_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(2, iteration_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(3, ciphertext_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.SenderKeyMessage}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessageOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_SenderKeyMessage_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_SenderKeyMessage_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage.class, org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        id_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        iteration_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000002);
+        ciphertext_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000004);
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_SenderKeyMessage_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage build() {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage buildPartial() {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage result = new org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.id_ = id_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        result.iteration_ = iteration_;
+        if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        result.ciphertext_ = ciphertext_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage) {
+          return mergeFrom((org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage other) {
+        if (other == org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage.getDefaultInstance()) return this;
+        if (other.hasId()) {
+          setId(other.getId());
+        }
+        if (other.hasIteration()) {
+          setIteration(other.getIteration());
+        }
+        if (other.hasCiphertext()) {
+          setCiphertext(other.getCiphertext());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyMessage) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional uint32 id = 1;
+      private int id_ ;
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public boolean hasId() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public int getId() {
+        return id_;
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public Builder setId(int value) {
+        bitField0_ |= 0x00000001;
+        id_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public Builder clearId() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        id_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional uint32 iteration = 2;
+      private int iteration_ ;
+      /**
+       * <code>optional uint32 iteration = 2;</code>
+       */
+      public boolean hasIteration() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional uint32 iteration = 2;</code>
+       */
+      public int getIteration() {
+        return iteration_;
+      }
+      /**
+       * <code>optional uint32 iteration = 2;</code>
+       */
+      public Builder setIteration(int value) {
+        bitField0_ |= 0x00000002;
+        iteration_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 iteration = 2;</code>
+       */
+      public Builder clearIteration() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        iteration_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional bytes ciphertext = 3;
+      private com.google.protobuf.ByteString ciphertext_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes ciphertext = 3;</code>
+       */
+      public boolean hasCiphertext() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional bytes ciphertext = 3;</code>
+       */
+      public com.google.protobuf.ByteString getCiphertext() {
+        return ciphertext_;
+      }
+      /**
+       * <code>optional bytes ciphertext = 3;</code>
+       */
+      public Builder setCiphertext(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000004;
+        ciphertext_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes ciphertext = 3;</code>
+       */
+      public Builder clearCiphertext() {
+        bitField0_ = (bitField0_ & ~0x00000004);
+        ciphertext_ = getDefaultInstance().getCiphertext();
+        onChanged();
+        return this;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.SenderKeyMessage)
+    }
+
+    static {
+      defaultInstance = new SenderKeyMessage(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.SenderKeyMessage)
+  }
+
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+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional uint32 id = 1;
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    boolean hasId();
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    int getId();
+
+    // optional uint32 iteration = 2;
+    /**
+     * <code>optional uint32 iteration = 2;</code>
+     */
+    boolean hasIteration();
+    /**
+     * <code>optional uint32 iteration = 2;</code>
+     */
+    int getIteration();
+
+    // optional bytes chainKey = 3;
+    /**
+     * <code>optional bytes chainKey = 3;</code>
+     */
+    boolean hasChainKey();
+    /**
+     * <code>optional bytes chainKey = 3;</code>
+     */
+    com.google.protobuf.ByteString getChainKey();
+
+    // optional bytes signingKey = 4;
+    /**
+     * <code>optional bytes signingKey = 4;</code>
+     */
+    boolean hasSigningKey();
+    /**
+     * <code>optional bytes signingKey = 4;</code>
+     */
+    com.google.protobuf.ByteString getSigningKey();
+  }
+  /**
+   * Protobuf type {@code textsecure.SenderKeyDistributionMessage}
+   */
+  public static final class SenderKeyDistributionMessage extends
+      com.google.protobuf.GeneratedMessage
+      implements SenderKeyDistributionMessageOrBuilder {
+    // Use SenderKeyDistributionMessage.newBuilder() to construct.
+    private SenderKeyDistributionMessage(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private SenderKeyDistributionMessage(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final SenderKeyDistributionMessage defaultInstance;
+    public static SenderKeyDistributionMessage getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public SenderKeyDistributionMessage getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private SenderKeyDistributionMessage(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 8: {
+              bitField0_ |= 0x00000001;
+              id_ = input.readUInt32();
+              break;
+            }
+            case 16: {
+              bitField0_ |= 0x00000002;
+              iteration_ = input.readUInt32();
+              break;
+            }
+            case 26: {
+              bitField0_ |= 0x00000004;
+              chainKey_ = input.readBytes();
+              break;
+            }
+            case 34: {
+              bitField0_ |= 0x00000008;
+              signingKey_ = input.readBytes();
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_SenderKeyDistributionMessage_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_SenderKeyDistributionMessage_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage.class, org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<SenderKeyDistributionMessage> PARSER =
+        new com.google.protobuf.AbstractParser<SenderKeyDistributionMessage>() {
+      public SenderKeyDistributionMessage parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new SenderKeyDistributionMessage(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<SenderKeyDistributionMessage> getParserForType() {
+      return PARSER;
+    }
+
+    private int bitField0_;
+    // optional uint32 id = 1;
+    public static final int ID_FIELD_NUMBER = 1;
+    private int id_;
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    public boolean hasId() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    public int getId() {
+      return id_;
+    }
+
+    // optional uint32 iteration = 2;
+    public static final int ITERATION_FIELD_NUMBER = 2;
+    private int iteration_;
+    /**
+     * <code>optional uint32 iteration = 2;</code>
+     */
+    public boolean hasIteration() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>optional uint32 iteration = 2;</code>
+     */
+    public int getIteration() {
+      return iteration_;
+    }
+
+    // optional bytes chainKey = 3;
+    public static final int CHAINKEY_FIELD_NUMBER = 3;
+    private com.google.protobuf.ByteString chainKey_;
+    /**
+     * <code>optional bytes chainKey = 3;</code>
+     */
+    public boolean hasChainKey() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>optional bytes chainKey = 3;</code>
+     */
+    public com.google.protobuf.ByteString getChainKey() {
+      return chainKey_;
+    }
+
+    // optional bytes signingKey = 4;
+    public static final int SIGNINGKEY_FIELD_NUMBER = 4;
+    private com.google.protobuf.ByteString signingKey_;
+    /**
+     * <code>optional bytes signingKey = 4;</code>
+     */
+    public boolean hasSigningKey() {
+      return ((bitField0_ & 0x00000008) == 0x00000008);
+    }
+    /**
+     * <code>optional bytes signingKey = 4;</code>
+     */
+    public com.google.protobuf.ByteString getSigningKey() {
+      return signingKey_;
+    }
+
+    private void initFields() {
+      id_ = 0;
+      iteration_ = 0;
+      chainKey_ = com.google.protobuf.ByteString.EMPTY;
+      signingKey_ = com.google.protobuf.ByteString.EMPTY;
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeUInt32(1, id_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeUInt32(2, iteration_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeBytes(3, chainKey_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        output.writeBytes(4, signingKey_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(1, id_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(2, iteration_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(3, chainKey_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(4, signingKey_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.SenderKeyDistributionMessage}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessageOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_SenderKeyDistributionMessage_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_SenderKeyDistributionMessage_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage.class, org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        id_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        iteration_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000002);
+        chainKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000004);
+        signingKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000008);
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.internal_static_textsecure_SenderKeyDistributionMessage_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage build() {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage buildPartial() {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage result = new org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
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+        result.id_ = id_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        result.iteration_ = iteration_;
+        if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        result.chainKey_ = chainKey_;
+        if (((from_bitField0_ & 0x00000008) == 0x00000008)) {
+          to_bitField0_ |= 0x00000008;
+        }
+        result.signingKey_ = signingKey_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage) {
+          return mergeFrom((org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage other) {
+        if (other == org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage.getDefaultInstance()) return this;
+        if (other.hasId()) {
+          setId(other.getId());
+        }
+        if (other.hasIteration()) {
+          setIteration(other.getIteration());
+        }
+        if (other.hasChainKey()) {
+          setChainKey(other.getChainKey());
+        }
+        if (other.hasSigningKey()) {
+          setSigningKey(other.getSigningKey());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.protocol.WhisperProtos.SenderKeyDistributionMessage) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional uint32 id = 1;
+      private int id_ ;
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public boolean hasId() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public int getId() {
+        return id_;
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public Builder setId(int value) {
+        bitField0_ |= 0x00000001;
+        id_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public Builder clearId() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        id_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional uint32 iteration = 2;
+      private int iteration_ ;
+      /**
+       * <code>optional uint32 iteration = 2;</code>
+       */
+      public boolean hasIteration() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional uint32 iteration = 2;</code>
+       */
+      public int getIteration() {
+        return iteration_;
+      }
+      /**
+       * <code>optional uint32 iteration = 2;</code>
+       */
+      public Builder setIteration(int value) {
+        bitField0_ |= 0x00000002;
+        iteration_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 iteration = 2;</code>
+       */
+      public Builder clearIteration() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        iteration_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional bytes chainKey = 3;
+      private com.google.protobuf.ByteString chainKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes chainKey = 3;</code>
+       */
+      public boolean hasChainKey() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional bytes chainKey = 3;</code>
+       */
+      public com.google.protobuf.ByteString getChainKey() {
+        return chainKey_;
+      }
+      /**
+       * <code>optional bytes chainKey = 3;</code>
+       */
+      public Builder setChainKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000004;
+        chainKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes chainKey = 3;</code>
+       */
+      public Builder clearChainKey() {
+        bitField0_ = (bitField0_ & ~0x00000004);
+        chainKey_ = getDefaultInstance().getChainKey();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes signingKey = 4;
+      private com.google.protobuf.ByteString signingKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes signingKey = 4;</code>
+       */
+      public boolean hasSigningKey() {
+        return ((bitField0_ & 0x00000008) == 0x00000008);
+      }
+      /**
+       * <code>optional bytes signingKey = 4;</code>
+       */
+      public com.google.protobuf.ByteString getSigningKey() {
+        return signingKey_;
+      }
+      /**
+       * <code>optional bytes signingKey = 4;</code>
+       */
+      public Builder setSigningKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000008;
+        signingKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes signingKey = 4;</code>
+       */
+      public Builder clearSigningKey() {
+        bitField0_ = (bitField0_ & ~0x00000008);
+        signingKey_ = getDefaultInstance().getSigningKey();
+        onChanged();
+        return this;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.SenderKeyDistributionMessage)
+    }
+
+    static {
+      defaultInstance = new SenderKeyDistributionMessage(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.SenderKeyDistributionMessage)
+  }
+
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_WhisperMessage_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_WhisperMessage_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_PreKeyWhisperMessage_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_PreKeyWhisperMessage_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_KeyExchangeMessage_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_KeyExchangeMessage_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SenderKeyMessage_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SenderKeyMessage_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SenderKeyDistributionMessage_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SenderKeyDistributionMessage_fieldAccessorTable;
+
+  public static com.google.protobuf.Descriptors.FileDescriptor
+      getDescriptor() {
+    return descriptor;
+  }
+  private static com.google.protobuf.Descriptors.FileDescriptor
+      descriptor;
+  static {
+    java.lang.String[] descriptorData = {
+      "\n\031WhisperTextProtocol.proto\022\ntextsecure\"" +
+      "b\n\016WhisperMessage\022\022\n\nratchetKey\030\001 \001(\014\022\017\n" +
+      "\007counter\030\002 \001(\r\022\027\n\017previousCounter\030\003 \001(\r\022" +
+      "\022\n\nciphertext\030\004 \001(\014\"\217\001\n\024PreKeyWhisperMes" +
+      "sage\022\026\n\016registrationId\030\005 \001(\r\022\020\n\010preKeyId" +
+      "\030\001 \001(\r\022\026\n\016signedPreKeyId\030\006 \001(\r\022\017\n\007baseKe" +
+      "y\030\002 \001(\014\022\023\n\013identityKey\030\003 \001(\014\022\017\n\007message\030" +
+      "\004 \001(\014\"t\n\022KeyExchangeMessage\022\n\n\002id\030\001 \001(\r\022" +
+      "\017\n\007baseKey\030\002 \001(\014\022\022\n\nratchetKey\030\003 \001(\014\022\023\n\013" +
+      "identityKey\030\004 \001(\014\022\030\n\020baseKeySignature\030\005 ",
+      "\001(\014\"E\n\020SenderKeyMessage\022\n\n\002id\030\001 \001(\r\022\021\n\ti" +
+      "teration\030\002 \001(\r\022\022\n\nciphertext\030\003 \001(\014\"c\n\034Se" +
+      "nderKeyDistributionMessage\022\n\n\002id\030\001 \001(\r\022\021" +
+      "\n\titeration\030\002 \001(\r\022\020\n\010chainKey\030\003 \001(\014\022\022\n\ns" +
+      "igningKey\030\004 \001(\014B7\n&org.whispersystems.li" +
+      "baxolotl.protocolB\rWhisperProtos"
+    };
+    com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
+      new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
+        public com.google.protobuf.ExtensionRegistry assignDescriptors(
+            com.google.protobuf.Descriptors.FileDescriptor root) {
+          descriptor = root;
+          internal_static_textsecure_WhisperMessage_descriptor =
+            getDescriptor().getMessageTypes().get(0);
+          internal_static_textsecure_WhisperMessage_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_WhisperMessage_descriptor,
+              new java.lang.String[] { "RatchetKey", "Counter", "PreviousCounter", "Ciphertext", });
+          internal_static_textsecure_PreKeyWhisperMessage_descriptor =
+            getDescriptor().getMessageTypes().get(1);
+          internal_static_textsecure_PreKeyWhisperMessage_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_PreKeyWhisperMessage_descriptor,
+              new java.lang.String[] { "RegistrationId", "PreKeyId", "SignedPreKeyId", "BaseKey", "IdentityKey", "Message", });
+          internal_static_textsecure_KeyExchangeMessage_descriptor =
+            getDescriptor().getMessageTypes().get(2);
+          internal_static_textsecure_KeyExchangeMessage_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_KeyExchangeMessage_descriptor,
+              new java.lang.String[] { "Id", "BaseKey", "RatchetKey", "IdentityKey", "BaseKeySignature", });
+          internal_static_textsecure_SenderKeyMessage_descriptor =
+            getDescriptor().getMessageTypes().get(3);
+          internal_static_textsecure_SenderKeyMessage_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SenderKeyMessage_descriptor,
+              new java.lang.String[] { "Id", "Iteration", "Ciphertext", });
+          internal_static_textsecure_SenderKeyDistributionMessage_descriptor =
+            getDescriptor().getMessageTypes().get(4);
+          internal_static_textsecure_SenderKeyDistributionMessage_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SenderKeyDistributionMessage_descriptor,
+              new java.lang.String[] { "Id", "Iteration", "ChainKey", "SigningKey", });
+          return null;
+        }
+      };
+    com.google.protobuf.Descriptors.FileDescriptor
+      .internalBuildGeneratedFileFrom(descriptorData,
+        new com.google.protobuf.Descriptors.FileDescriptor[] {
+        }, assigner);
+  }
+
+  // @@protoc_insertion_point(outer_class_scope)
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ratchet/AliceAxolotlParameters.java b/src/main/java/org/whispersystems/libaxolotl/ratchet/AliceAxolotlParameters.java
new file mode 100644
index 00000000..13c995e9
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ratchet/AliceAxolotlParameters.java
@@ -0,0 +1,109 @@
+package org.whispersystems.libaxolotl.ratchet;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.IdentityKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.util.guava.Optional;
+
+public class AliceAxolotlParameters {
+
+  private final IdentityKeyPair       ourIdentityKey;
+  private final ECKeyPair             ourBaseKey;
+
+  private final IdentityKey           theirIdentityKey;
+  private final ECPublicKey           theirSignedPreKey;
+  private final Optional<ECPublicKey> theirOneTimePreKey;
+  private final ECPublicKey           theirRatchetKey;
+
+  private AliceAxolotlParameters(IdentityKeyPair ourIdentityKey, ECKeyPair ourBaseKey,
+                                 IdentityKey theirIdentityKey, ECPublicKey theirSignedPreKey,
+                                 ECPublicKey theirRatchetKey, Optional<ECPublicKey> theirOneTimePreKey)
+  {
+    this.ourIdentityKey     = ourIdentityKey;
+    this.ourBaseKey         = ourBaseKey;
+    this.theirIdentityKey   = theirIdentityKey;
+    this.theirSignedPreKey  = theirSignedPreKey;
+    this.theirRatchetKey    = theirRatchetKey;
+    this.theirOneTimePreKey = theirOneTimePreKey;
+
+    if (ourIdentityKey == null || ourBaseKey == null || theirIdentityKey == null ||
+        theirSignedPreKey == null || theirRatchetKey == null || theirOneTimePreKey == null)
+    {
+      throw new IllegalArgumentException("Null values!");
+    }
+  }
+
+  public IdentityKeyPair getOurIdentityKey() {
+    return ourIdentityKey;
+  }
+
+  public ECKeyPair getOurBaseKey() {
+    return ourBaseKey;
+  }
+
+  public IdentityKey getTheirIdentityKey() {
+    return theirIdentityKey;
+  }
+
+  public ECPublicKey getTheirSignedPreKey() {
+    return theirSignedPreKey;
+  }
+
+  public Optional<ECPublicKey> getTheirOneTimePreKey() {
+    return theirOneTimePreKey;
+  }
+
+  public static Builder newBuilder() {
+    return new Builder();
+  }
+
+  public ECPublicKey getTheirRatchetKey() {
+    return theirRatchetKey;
+  }
+
+  public static class Builder {
+    private IdentityKeyPair       ourIdentityKey;
+    private ECKeyPair             ourBaseKey;
+
+    private IdentityKey           theirIdentityKey;
+    private ECPublicKey           theirSignedPreKey;
+    private ECPublicKey           theirRatchetKey;
+    private Optional<ECPublicKey> theirOneTimePreKey;
+
+    public Builder setOurIdentityKey(IdentityKeyPair ourIdentityKey) {
+      this.ourIdentityKey = ourIdentityKey;
+      return this;
+    }
+
+    public Builder setOurBaseKey(ECKeyPair ourBaseKey) {
+      this.ourBaseKey = ourBaseKey;
+      return this;
+    }
+
+    public Builder setTheirRatchetKey(ECPublicKey theirRatchetKey) {
+      this.theirRatchetKey = theirRatchetKey;
+      return this;
+    }
+
+    public Builder setTheirIdentityKey(IdentityKey theirIdentityKey) {
+      this.theirIdentityKey = theirIdentityKey;
+      return this;
+    }
+
+    public Builder setTheirSignedPreKey(ECPublicKey theirSignedPreKey) {
+      this.theirSignedPreKey = theirSignedPreKey;
+      return this;
+    }
+
+    public Builder setTheirOneTimePreKey(Optional<ECPublicKey> theirOneTimePreKey) {
+      this.theirOneTimePreKey = theirOneTimePreKey;
+      return this;
+    }
+
+    public AliceAxolotlParameters create() {
+      return new AliceAxolotlParameters(ourIdentityKey, ourBaseKey, theirIdentityKey,
+                                        theirSignedPreKey, theirRatchetKey, theirOneTimePreKey);
+    }
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ratchet/BobAxolotlParameters.java b/src/main/java/org/whispersystems/libaxolotl/ratchet/BobAxolotlParameters.java
new file mode 100644
index 00000000..27116a8b
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ratchet/BobAxolotlParameters.java
@@ -0,0 +1,109 @@
+package org.whispersystems.libaxolotl.ratchet;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.IdentityKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.util.guava.Optional;
+
+public class BobAxolotlParameters {
+
+  private final IdentityKeyPair     ourIdentityKey;
+  private final ECKeyPair           ourSignedPreKey;
+  private final Optional<ECKeyPair> ourOneTimePreKey;
+  private final ECKeyPair           ourRatchetKey;
+
+  private final IdentityKey         theirIdentityKey;
+  private final ECPublicKey         theirBaseKey;
+
+  BobAxolotlParameters(IdentityKeyPair ourIdentityKey, ECKeyPair ourSignedPreKey,
+                       ECKeyPair ourRatchetKey, Optional<ECKeyPair> ourOneTimePreKey,
+                       IdentityKey theirIdentityKey, ECPublicKey theirBaseKey)
+  {
+    this.ourIdentityKey   = ourIdentityKey;
+    this.ourSignedPreKey  = ourSignedPreKey;
+    this.ourRatchetKey    = ourRatchetKey;
+    this.ourOneTimePreKey = ourOneTimePreKey;
+    this.theirIdentityKey = theirIdentityKey;
+    this.theirBaseKey     = theirBaseKey;
+
+    if (ourIdentityKey == null || ourSignedPreKey == null || ourRatchetKey == null ||
+        ourOneTimePreKey == null || theirIdentityKey == null || theirBaseKey == null)
+    {
+      throw new IllegalArgumentException("Null value!");
+    }
+  }
+
+  public IdentityKeyPair getOurIdentityKey() {
+    return ourIdentityKey;
+  }
+
+  public ECKeyPair getOurSignedPreKey() {
+    return ourSignedPreKey;
+  }
+
+  public Optional<ECKeyPair> getOurOneTimePreKey() {
+    return ourOneTimePreKey;
+  }
+
+  public IdentityKey getTheirIdentityKey() {
+    return theirIdentityKey;
+  }
+
+  public ECPublicKey getTheirBaseKey() {
+    return theirBaseKey;
+  }
+
+  public static Builder newBuilder() {
+    return new Builder();
+  }
+
+  public ECKeyPair getOurRatchetKey() {
+    return ourRatchetKey;
+  }
+
+  public static class Builder {
+    private IdentityKeyPair     ourIdentityKey;
+    private ECKeyPair           ourSignedPreKey;
+    private Optional<ECKeyPair> ourOneTimePreKey;
+    private ECKeyPair           ourRatchetKey;
+
+    private IdentityKey         theirIdentityKey;
+    private ECPublicKey         theirBaseKey;
+
+    public Builder setOurIdentityKey(IdentityKeyPair ourIdentityKey) {
+      this.ourIdentityKey = ourIdentityKey;
+      return this;
+    }
+
+    public Builder setOurSignedPreKey(ECKeyPair ourSignedPreKey) {
+      this.ourSignedPreKey = ourSignedPreKey;
+      return this;
+    }
+
+    public Builder setOurOneTimePreKey(Optional<ECKeyPair> ourOneTimePreKey) {
+      this.ourOneTimePreKey = ourOneTimePreKey;
+      return this;
+    }
+
+    public Builder setTheirIdentityKey(IdentityKey theirIdentityKey) {
+      this.theirIdentityKey = theirIdentityKey;
+      return this;
+    }
+
+    public Builder setTheirBaseKey(ECPublicKey theirBaseKey) {
+      this.theirBaseKey = theirBaseKey;
+      return this;
+    }
+
+    public Builder setOurRatchetKey(ECKeyPair ourRatchetKey) {
+      this.ourRatchetKey = ourRatchetKey;
+      return this;
+    }
+
+    public BobAxolotlParameters create() {
+      return new BobAxolotlParameters(ourIdentityKey, ourSignedPreKey, ourRatchetKey,
+                                      ourOneTimePreKey, theirIdentityKey, theirBaseKey);
+    }
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ratchet/ChainKey.java b/src/main/java/org/whispersystems/libaxolotl/ratchet/ChainKey.java
new file mode 100644
index 00000000..9dd1dbee
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ratchet/ChainKey.java
@@ -0,0 +1,75 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.ratchet;
+
+
+import org.whispersystems.libaxolotl.kdf.DerivedMessageSecrets;
+import org.whispersystems.libaxolotl.kdf.HKDF;
+
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+
+public class ChainKey {
+
+  private static final byte[] MESSAGE_KEY_SEED = {0x01};
+  private static final byte[] CHAIN_KEY_SEED   = {0x02};
+
+  private final HKDF   kdf;
+  private final byte[] key;
+  private final int    index;
+
+  public ChainKey(HKDF kdf, byte[] key, int index) {
+    this.kdf   = kdf;
+    this.key   = key;
+    this.index = index;
+  }
+
+  public byte[] getKey() {
+    return key;
+  }
+
+  public int getIndex() {
+    return index;
+  }
+
+  public ChainKey getNextChainKey() {
+    byte[] nextKey = getBaseMaterial(CHAIN_KEY_SEED);
+    return new ChainKey(kdf, nextKey, index + 1);
+  }
+
+  public MessageKeys getMessageKeys() {
+    byte[]                inputKeyMaterial = getBaseMaterial(MESSAGE_KEY_SEED);
+    byte[]                keyMaterialBytes = kdf.deriveSecrets(inputKeyMaterial, "WhisperMessageKeys".getBytes(), DerivedMessageSecrets.SIZE);
+    DerivedMessageSecrets keyMaterial      = new DerivedMessageSecrets(keyMaterialBytes);
+
+    return new MessageKeys(keyMaterial.getCipherKey(), keyMaterial.getMacKey(), keyMaterial.getIv(), index);
+  }
+
+  private byte[] getBaseMaterial(byte[] seed) {
+    try {
+      Mac mac = Mac.getInstance("HmacSHA256");
+      mac.init(new SecretKeySpec(key, "HmacSHA256"));
+
+      return mac.doFinal(seed);
+    } catch (NoSuchAlgorithmException | InvalidKeyException e) {
+      throw new AssertionError(e);
+    }
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ratchet/MessageKeys.java b/src/main/java/org/whispersystems/libaxolotl/ratchet/MessageKeys.java
new file mode 100644
index 00000000..95a8c7dc
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ratchet/MessageKeys.java
@@ -0,0 +1,51 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.ratchet;
+
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+public class MessageKeys {
+
+  private final SecretKeySpec   cipherKey;
+  private final SecretKeySpec   macKey;
+  private final IvParameterSpec iv;
+  private final int             counter;
+
+  public MessageKeys(SecretKeySpec cipherKey, SecretKeySpec macKey, IvParameterSpec iv, int counter) {
+    this.cipherKey = cipherKey;
+    this.macKey    = macKey;
+    this.iv        = iv;
+    this.counter   = counter;
+  }
+
+  public SecretKeySpec getCipherKey() {
+    return cipherKey;
+  }
+
+  public SecretKeySpec getMacKey() {
+    return macKey;
+  }
+
+  public IvParameterSpec getIv() {
+    return iv;
+  }
+
+  public int getCounter() {
+    return counter;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ratchet/RatchetingSession.java b/src/main/java/org/whispersystems/libaxolotl/ratchet/RatchetingSession.java
new file mode 100644
index 00000000..8c094ec0
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ratchet/RatchetingSession.java
@@ -0,0 +1,179 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.ratchet;
+
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.kdf.HKDF;
+import org.whispersystems.libaxolotl.state.SessionState;
+import org.whispersystems.libaxolotl.util.ByteUtil;
+import org.whispersystems.libaxolotl.util.Pair;
+import org.whispersystems.libaxolotl.util.guava.Optional;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.Arrays;
+
+public class RatchetingSession {
+
+  public static void initializeSession(SessionState sessionState,
+                                       int sessionVersion,
+                                       SymmetricAxolotlParameters parameters)
+      throws InvalidKeyException
+  {
+    if (isAlice(parameters.getOurBaseKey().getPublicKey(), parameters.getTheirBaseKey())) {
+      AliceAxolotlParameters.Builder aliceParameters = AliceAxolotlParameters.newBuilder();
+
+      aliceParameters.setOurBaseKey(parameters.getOurBaseKey())
+                     .setOurIdentityKey(parameters.getOurIdentityKey())
+                     .setTheirRatchetKey(parameters.getTheirRatchetKey())
+                     .setTheirIdentityKey(parameters.getTheirIdentityKey())
+                     .setTheirSignedPreKey(parameters.getTheirBaseKey())
+                     .setTheirOneTimePreKey(Optional.<ECPublicKey>absent());
+
+      RatchetingSession.initializeSession(sessionState, sessionVersion, aliceParameters.create());
+    } else {
+      BobAxolotlParameters.Builder bobParameters = BobAxolotlParameters.newBuilder();
+
+      bobParameters.setOurIdentityKey(parameters.getOurIdentityKey())
+                   .setOurRatchetKey(parameters.getOurRatchetKey())
+                   .setOurSignedPreKey(parameters.getOurBaseKey())
+                   .setOurOneTimePreKey(Optional.<ECKeyPair>absent())
+                   .setTheirBaseKey(parameters.getTheirBaseKey())
+                   .setTheirIdentityKey(parameters.getTheirIdentityKey());
+
+      RatchetingSession.initializeSession(sessionState, sessionVersion, bobParameters.create());
+    }
+  }
+
+  public static void initializeSession(SessionState sessionState,
+                                       int sessionVersion,
+                                       AliceAxolotlParameters parameters)
+      throws InvalidKeyException
+  {
+    try {
+      sessionState.setSessionVersion(sessionVersion);
+      sessionState.setRemoteIdentityKey(parameters.getTheirIdentityKey());
+      sessionState.setLocalIdentityKey(parameters.getOurIdentityKey().getPublicKey());
+
+      ECKeyPair             sendingRatchetKey = Curve.generateKeyPair();
+      ByteArrayOutputStream secrets           = new ByteArrayOutputStream();
+
+      if (sessionVersion >= 3) {
+        secrets.write(getDiscontinuityBytes());
+      }
+
+      secrets.write(Curve.calculateAgreement(parameters.getTheirSignedPreKey(),
+                                             parameters.getOurIdentityKey().getPrivateKey()));
+      secrets.write(Curve.calculateAgreement(parameters.getTheirIdentityKey().getPublicKey(),
+                                             parameters.getOurBaseKey().getPrivateKey()));
+      secrets.write(Curve.calculateAgreement(parameters.getTheirSignedPreKey(),
+                                             parameters.getOurBaseKey().getPrivateKey()));
+
+      if (sessionVersion >= 3 & parameters.getTheirOneTimePreKey().isPresent()) {
+        secrets.write(Curve.calculateAgreement(parameters.getTheirOneTimePreKey().get(),
+                                               parameters.getOurBaseKey().getPrivateKey()));
+      }
+
+      DerivedKeys             derivedKeys  = calculateDerivedKeys(sessionVersion, secrets.toByteArray());
+      Pair<RootKey, ChainKey> sendingChain = derivedKeys.getRootKey().createChain(parameters.getTheirRatchetKey(), sendingRatchetKey);
+
+      sessionState.addReceiverChain(parameters.getTheirRatchetKey(), derivedKeys.getChainKey());
+      sessionState.setSenderChain(sendingRatchetKey, sendingChain.second());
+      sessionState.setRootKey(sendingChain.first());
+    } catch (IOException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public static void initializeSession(SessionState sessionState,
+                                       int sessionVersion,
+                                       BobAxolotlParameters parameters)
+      throws InvalidKeyException
+  {
+
+    try {
+      sessionState.setSessionVersion(sessionVersion);
+      sessionState.setRemoteIdentityKey(parameters.getTheirIdentityKey());
+      sessionState.setLocalIdentityKey(parameters.getOurIdentityKey().getPublicKey());
+
+      ByteArrayOutputStream secrets = new ByteArrayOutputStream();
+
+      if (sessionVersion >= 3) {
+        secrets.write(getDiscontinuityBytes());
+      }
+
+      secrets.write(Curve.calculateAgreement(parameters.getTheirIdentityKey().getPublicKey(),
+                                             parameters.getOurSignedPreKey().getPrivateKey()));
+      secrets.write(Curve.calculateAgreement(parameters.getTheirBaseKey(),
+                                             parameters.getOurIdentityKey().getPrivateKey()));
+      secrets.write(Curve.calculateAgreement(parameters.getTheirBaseKey(),
+                                             parameters.getOurSignedPreKey().getPrivateKey()));
+
+      if (sessionVersion >= 3 && parameters.getOurOneTimePreKey().isPresent()) {
+        secrets.write(Curve.calculateAgreement(parameters.getTheirBaseKey(),
+                                               parameters.getOurOneTimePreKey().get().getPrivateKey()));
+      }
+
+      DerivedKeys derivedKeys = calculateDerivedKeys(sessionVersion, secrets.toByteArray());
+
+      sessionState.setSenderChain(parameters.getOurRatchetKey(), derivedKeys.getChainKey());
+      sessionState.setRootKey(derivedKeys.getRootKey());
+    } catch (IOException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  private static byte[] getDiscontinuityBytes() {
+    byte[] discontinuity = new byte[32];
+    Arrays.fill(discontinuity, (byte) 0xFF);
+    return discontinuity;
+  }
+
+  private static DerivedKeys calculateDerivedKeys(int sessionVersion, byte[] masterSecret) {
+    HKDF     kdf                = HKDF.createFor(sessionVersion);
+    byte[]   derivedSecretBytes = kdf.deriveSecrets(masterSecret, "WhisperText".getBytes(), 64);
+    byte[][] derivedSecrets     = ByteUtil.split(derivedSecretBytes, 32, 32);
+
+    return new DerivedKeys(new RootKey(kdf, derivedSecrets[0]),
+                           new ChainKey(kdf, derivedSecrets[1], 0));
+  }
+
+  private static boolean isAlice(ECPublicKey ourKey, ECPublicKey theirKey) {
+    return ourKey.compareTo(theirKey) < 0;
+  }
+
+  private static class DerivedKeys {
+    private final RootKey   rootKey;
+    private final ChainKey  chainKey;
+
+    private DerivedKeys(RootKey rootKey, ChainKey chainKey) {
+      this.rootKey   = rootKey;
+      this.chainKey  = chainKey;
+    }
+
+    public RootKey getRootKey() {
+      return rootKey;
+    }
+
+    public ChainKey getChainKey() {
+      return chainKey;
+    }
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ratchet/RootKey.java b/src/main/java/org/whispersystems/libaxolotl/ratchet/RootKey.java
new file mode 100644
index 00000000..39f3a831
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ratchet/RootKey.java
@@ -0,0 +1,54 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.ratchet;
+
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.kdf.DerivedRootSecrets;
+import org.whispersystems.libaxolotl.kdf.HKDF;
+import org.whispersystems.libaxolotl.util.ByteUtil;
+import org.whispersystems.libaxolotl.util.Pair;
+
+public class RootKey {
+
+  private final HKDF   kdf;
+  private final byte[] key;
+
+  public RootKey(HKDF kdf, byte[] key) {
+    this.kdf = kdf;
+    this.key = key;
+  }
+
+  public byte[] getKeyBytes() {
+    return key;
+  }
+
+  public Pair<RootKey, ChainKey> createChain(ECPublicKey theirRatchetKey, ECKeyPair ourRatchetKey)
+      throws InvalidKeyException
+  {
+    byte[]             sharedSecret       = Curve.calculateAgreement(theirRatchetKey, ourRatchetKey.getPrivateKey());
+    byte[]             derivedSecretBytes = kdf.deriveSecrets(sharedSecret, key, "WhisperRatchet".getBytes(), DerivedRootSecrets.SIZE);
+    DerivedRootSecrets derivedSecrets     = new DerivedRootSecrets(derivedSecretBytes);
+
+    RootKey  newRootKey  = new RootKey(kdf, derivedSecrets.getRootKey());
+    ChainKey newChainKey = new ChainKey(kdf, derivedSecrets.getChainKey(), 0);
+
+    return new Pair<>(newRootKey, newChainKey);
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/ratchet/SymmetricAxolotlParameters.java b/src/main/java/org/whispersystems/libaxolotl/ratchet/SymmetricAxolotlParameters.java
new file mode 100644
index 00000000..7a63c45f
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/ratchet/SymmetricAxolotlParameters.java
@@ -0,0 +1,108 @@
+package org.whispersystems.libaxolotl.ratchet;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.IdentityKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+
+public class SymmetricAxolotlParameters {
+
+  private final ECKeyPair       ourBaseKey;
+  private final ECKeyPair       ourRatchetKey;
+  private final IdentityKeyPair ourIdentityKey;
+
+  private final ECPublicKey     theirBaseKey;
+  private final ECPublicKey     theirRatchetKey;
+  private final IdentityKey     theirIdentityKey;
+
+  SymmetricAxolotlParameters(ECKeyPair ourBaseKey, ECKeyPair ourRatchetKey,
+                             IdentityKeyPair ourIdentityKey, ECPublicKey theirBaseKey,
+                             ECPublicKey theirRatchetKey, IdentityKey theirIdentityKey)
+  {
+    this.ourBaseKey       = ourBaseKey;
+    this.ourRatchetKey    = ourRatchetKey;
+    this.ourIdentityKey   = ourIdentityKey;
+    this.theirBaseKey     = theirBaseKey;
+    this.theirRatchetKey  = theirRatchetKey;
+    this.theirIdentityKey = theirIdentityKey;
+
+    if (ourBaseKey == null || ourRatchetKey == null || ourIdentityKey == null ||
+        theirBaseKey == null || theirRatchetKey == null || theirIdentityKey == null)
+    {
+      throw new IllegalArgumentException("Null values!");
+    }
+  }
+
+  public ECKeyPair getOurBaseKey() {
+    return ourBaseKey;
+  }
+
+  public ECKeyPair getOurRatchetKey() {
+    return ourRatchetKey;
+  }
+
+  public IdentityKeyPair getOurIdentityKey() {
+    return ourIdentityKey;
+  }
+
+  public ECPublicKey getTheirBaseKey() {
+    return theirBaseKey;
+  }
+
+  public ECPublicKey getTheirRatchetKey() {
+    return theirRatchetKey;
+  }
+
+  public IdentityKey getTheirIdentityKey() {
+    return theirIdentityKey;
+  }
+
+  public static Builder newBuilder() {
+    return new Builder();
+  }
+
+  public static class Builder {
+    private ECKeyPair       ourBaseKey;
+    private ECKeyPair       ourRatchetKey;
+    private IdentityKeyPair ourIdentityKey;
+
+    private ECPublicKey     theirBaseKey;
+    private ECPublicKey     theirRatchetKey;
+    private IdentityKey     theirIdentityKey;
+
+    public Builder setOurBaseKey(ECKeyPair ourBaseKey) {
+      this.ourBaseKey = ourBaseKey;
+      return this;
+    }
+
+    public Builder setOurRatchetKey(ECKeyPair ourRatchetKey) {
+      this.ourRatchetKey = ourRatchetKey;
+      return this;
+    }
+
+    public Builder setOurIdentityKey(IdentityKeyPair ourIdentityKey) {
+      this.ourIdentityKey = ourIdentityKey;
+      return this;
+    }
+
+    public Builder setTheirBaseKey(ECPublicKey theirBaseKey) {
+      this.theirBaseKey = theirBaseKey;
+      return this;
+    }
+
+    public Builder setTheirRatchetKey(ECPublicKey theirRatchetKey) {
+      this.theirRatchetKey = theirRatchetKey;
+      return this;
+    }
+
+    public Builder setTheirIdentityKey(IdentityKey theirIdentityKey) {
+      this.theirIdentityKey = theirIdentityKey;
+      return this;
+    }
+
+    public SymmetricAxolotlParameters create() {
+      return new SymmetricAxolotlParameters(ourBaseKey, ourRatchetKey, ourIdentityKey,
+                                            theirBaseKey, theirRatchetKey, theirIdentityKey);
+    }
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/state/AxolotlStore.java b/src/main/java/org/whispersystems/libaxolotl/state/AxolotlStore.java
new file mode 100644
index 00000000..2fda9a21
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/state/AxolotlStore.java
@@ -0,0 +1,6 @@
+package org.whispersystems.libaxolotl.state;
+
+public interface AxolotlStore
+    extends IdentityKeyStore, PreKeyStore, SessionStore, SignedPreKeyStore
+{
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/state/IdentityKeyStore.java b/src/main/java/org/whispersystems/libaxolotl/state/IdentityKeyStore.java
new file mode 100644
index 00000000..d2024f78
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/state/IdentityKeyStore.java
@@ -0,0 +1,57 @@
+package org.whispersystems.libaxolotl.state;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.IdentityKeyPair;
+
+/**
+ * Provides an interface to identity information.
+ *
+ * @author Moxie Marlinspike
+ */
+public interface IdentityKeyStore {
+
+  /**
+   * Get the local client's identity key pair.
+   *
+   * @return The local client's persistent identity key pair.
+   */
+  public IdentityKeyPair getIdentityKeyPair();
+
+  /**
+   * Return the local client's registration ID.
+   * <p>
+   * Clients should maintain a registration ID, a random number
+   * between 1 and 16380 that's generated once at install time.
+   *
+   * @return the local client's registration ID.
+   */
+  public int             getLocalRegistrationId();
+
+  /**
+   * Save a remote client's identity key
+   * <p>
+   * Store a remote client's identity key as trusted.
+   *
+   * @param recipientId The recipient ID of the remote client.
+   * @param identityKey The remote client's identity key.
+   */
+  public void            saveIdentity(long recipientId, IdentityKey identityKey);
+
+
+  /**
+   * Verify a remote client's identity key.
+   * <p>
+   * Determine whether a remote client's identity is trusted.  Convention is
+   * that the TextSecure protocol is 'trust on first use.'  This means that
+   * an identity key is considered 'trusted' if there is no entry for the recipient
+   * in the local store, or if it matches the saved key for a recipient in the local
+   * store.  Only if it mismatches an entry in the local store is it considered
+   * 'untrusted.'
+   *
+   * @param recipientId The recipient ID of the remote client.
+   * @param identityKey The identity key to verify.
+   * @return true if trusted, false if untrusted.
+   */
+  public boolean         isTrustedIdentity(long recipientId, IdentityKey identityKey);
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/state/PreKeyBundle.java b/src/main/java/org/whispersystems/libaxolotl/state/PreKeyBundle.java
new file mode 100644
index 00000000..772bcc14
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/state/PreKeyBundle.java
@@ -0,0 +1,96 @@
+package org.whispersystems.libaxolotl.state;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+
+/**
+ * A class that contains a remote PreKey and collection
+ * of associated items.
+ *
+ * @author Moxie Marlinspike
+ */
+public class PreKeyBundle {
+
+  private int         registrationId;
+
+  private int         deviceId;
+
+  private int         preKeyId;
+  private ECPublicKey preKeyPublic;
+
+  private int         signedPreKeyId;
+  private ECPublicKey signedPreKeyPublic;
+  private byte[]      signedPreKeySignature;
+
+  private IdentityKey identityKey;
+
+  public PreKeyBundle(int registrationId, int deviceId, int preKeyId, ECPublicKey preKeyPublic,
+                      int signedPreKeyId, ECPublicKey signedPreKeyPublic, byte[] signedPreKeySignature,
+                      IdentityKey identityKey)
+  {
+    this.registrationId        = registrationId;
+    this.deviceId              = deviceId;
+    this.preKeyId              = preKeyId;
+    this.preKeyPublic          = preKeyPublic;
+    this.signedPreKeyId        = signedPreKeyId;
+    this.signedPreKeyPublic    = signedPreKeyPublic;
+    this.signedPreKeySignature = signedPreKeySignature;
+    this.identityKey           = identityKey;
+  }
+
+  /**
+   * @return the device ID this PreKey belongs to.
+   */
+  public int getDeviceId() {
+    return deviceId;
+  }
+
+  /**
+   * @return the unique key ID for this PreKey.
+   */
+  public int getPreKeyId() {
+    return preKeyId;
+  }
+
+  /**
+   * @return the public key for this PreKey.
+   */
+  public ECPublicKey getPreKey() {
+    return preKeyPublic;
+  }
+
+  /**
+   * @return the unique key ID for this signed prekey.
+   */
+  public int getSignedPreKeyId() {
+    return signedPreKeyId;
+  }
+
+  /**
+   * @return the signed prekey for this PreKeyBundle.
+   */
+  public ECPublicKey getSignedPreKey() {
+    return signedPreKeyPublic;
+  }
+
+  /**
+   * @return the signature over the signed  prekey.
+   */
+  public byte[] getSignedPreKeySignature() {
+    return signedPreKeySignature;
+  }
+
+  /**
+   * @return the {@link org.whispersystems.libaxolotl.IdentityKey} of this PreKeys owner.
+   */
+  public IdentityKey getIdentityKey() {
+    return identityKey;
+  }
+
+  /**
+   * @return the registration ID associated with this PreKey.
+   */
+  public int getRegistrationId() {
+    return registrationId;
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/state/PreKeyRecord.java b/src/main/java/org/whispersystems/libaxolotl/state/PreKeyRecord.java
new file mode 100644
index 00000000..0ea905f4
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/state/PreKeyRecord.java
@@ -0,0 +1,51 @@
+package org.whispersystems.libaxolotl.state;
+
+import com.google.protobuf.ByteString;
+
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPrivateKey;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+
+import java.io.IOException;
+
+import static org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure;
+
+public class PreKeyRecord {
+
+  private PreKeyRecordStructure structure;
+
+  public PreKeyRecord(int id, ECKeyPair keyPair) {
+    this.structure = PreKeyRecordStructure.newBuilder()
+                                          .setId(id)
+                                          .setPublicKey(ByteString.copyFrom(keyPair.getPublicKey()
+                                                                                   .serialize()))
+                                          .setPrivateKey(ByteString.copyFrom(keyPair.getPrivateKey()
+                                                                                    .serialize()))
+                                          .build();
+  }
+
+  public PreKeyRecord(byte[] serialized) throws IOException {
+    this.structure = PreKeyRecordStructure.parseFrom(serialized);
+  }
+
+  public int getId() {
+    return this.structure.getId();
+  }
+
+  public ECKeyPair getKeyPair() {
+    try {
+      ECPublicKey publicKey = Curve.decodePoint(this.structure.getPublicKey().toByteArray(), 0);
+      ECPrivateKey privateKey = Curve.decodePrivatePoint(this.structure.getPrivateKey().toByteArray());
+
+      return new ECKeyPair(publicKey, privateKey);
+    } catch (InvalidKeyException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public byte[] serialize() {
+    return this.structure.toByteArray();
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/state/PreKeyStore.java b/src/main/java/org/whispersystems/libaxolotl/state/PreKeyStore.java
new file mode 100644
index 00000000..7dc5e626
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/state/PreKeyStore.java
@@ -0,0 +1,42 @@
+package org.whispersystems.libaxolotl.state;
+
+import org.whispersystems.libaxolotl.InvalidKeyIdException;
+
+/**
+ * An interface describing the local storage of {@link PreKeyRecord}s.
+ *
+ * @author Moxie Marlinspike
+ */
+public interface PreKeyStore {
+
+  /**
+   * Load a local PreKeyRecord.
+   *
+   * @param preKeyId the ID of the local PreKeyRecord.
+   * @return the corresponding PreKeyRecord.
+   * @throws InvalidKeyIdException when there is no corresponding PreKeyRecord.
+   */
+  public PreKeyRecord loadPreKey(int preKeyId) throws InvalidKeyIdException;
+
+  /**
+   * Store a local PreKeyRecord.
+   *
+   * @param preKeyId the ID of the PreKeyRecord to store.
+   * @param record the PreKeyRecord.
+   */
+  public void         storePreKey(int preKeyId, PreKeyRecord record);
+
+  /**
+   * @param preKeyId A PreKeyRecord ID.
+   * @return true if the store has a record for the preKeyId, otherwise false.
+   */
+  public boolean      containsPreKey(int preKeyId);
+
+  /**
+   * Delete a PreKeyRecord from local storage.
+   *
+   * @param preKeyId The ID of the PreKeyRecord to remove.
+   */
+  public void         removePreKey(int preKeyId);
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/state/SessionRecord.java b/src/main/java/org/whispersystems/libaxolotl/state/SessionRecord.java
new file mode 100644
index 00000000..76c64922
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/state/SessionRecord.java
@@ -0,0 +1,117 @@
+package org.whispersystems.libaxolotl.state;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+
+import static org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure;
+import static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure;
+
+/**
+ * A SessionRecord encapsulates the state of an ongoing session.
+ *
+ * @author Moxie Marlinspike
+ */
+public class SessionRecord {
+
+  private static final int ARCHIVED_STATES_MAX_LENGTH = 40;
+
+  private SessionState             sessionState   = new SessionState();
+  private LinkedList<SessionState> previousStates = new LinkedList<>();
+  private boolean                  fresh          = false;
+
+  public SessionRecord() {
+    this.fresh = true;
+  }
+
+  public SessionRecord(SessionState sessionState) {
+    this.sessionState = sessionState;
+    this.fresh        = false;
+  }
+
+  public SessionRecord(byte[] serialized) throws IOException {
+    RecordStructure record = RecordStructure.parseFrom(serialized);
+    this.sessionState = new SessionState(record.getCurrentSession());
+    this.fresh        = false;
+
+    for (SessionStructure previousStructure : record.getPreviousSessionsList()) {
+      previousStates.add(new SessionState(previousStructure));
+    }
+  }
+
+  public boolean hasSessionState(int version, byte[] aliceBaseKey) {
+    if (sessionState.getSessionVersion() == version &&
+        Arrays.equals(aliceBaseKey, sessionState.getAliceBaseKey()))
+    {
+      return true;
+    }
+
+    for (SessionState state : previousStates) {
+      if (state.getSessionVersion() == version &&
+          Arrays.equals(aliceBaseKey, state.getAliceBaseKey()))
+      {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+  public SessionState getSessionState() {
+    return sessionState;
+  }
+
+  /**
+   * @return the list of all currently maintained "previous" session states.
+   */
+  public List<SessionState> getPreviousSessionStates() {
+    return previousStates;
+  }
+
+
+  public boolean isFresh() {
+    return fresh;
+  }
+
+  /**
+   * Move the current {@link SessionState} into the list of "previous" session states,
+   * and replace the current {@link org.whispersystems.libaxolotl.state.SessionState}
+   * with a fresh reset instance.
+   */
+  public void archiveCurrentState() {
+    promoteState(new SessionState());
+  }
+
+  public void promoteState(SessionState promotedState) {
+    this.previousStates.addFirst(sessionState);
+    this.sessionState = promotedState;
+
+    if (previousStates.size() > ARCHIVED_STATES_MAX_LENGTH) {
+      previousStates.removeLast();
+    }
+  }
+
+  public void setState(SessionState sessionState) {
+    this.sessionState = sessionState;
+  }
+
+  /**
+   * @return a serialized version of the current SessionRecord.
+   */
+  public byte[] serialize() {
+    List<SessionStructure> previousStructures = new LinkedList<>();
+
+    for (SessionState previousState : previousStates) {
+      previousStructures.add(previousState.getStructure());
+    }
+
+    RecordStructure record = RecordStructure.newBuilder()
+                                            .setCurrentSession(sessionState.getStructure())
+                                            .addAllPreviousSessions(previousStructures)
+                                            .build();
+
+    return record.toByteArray();
+  }
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/state/SessionState.java b/src/main/java/org/whispersystems/libaxolotl/state/SessionState.java
new file mode 100644
index 00000000..9b2b1e2a
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/state/SessionState.java
@@ -0,0 +1,509 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.whispersystems.libaxolotl.state;
+
+import android.util.Log;
+
+import com.google.protobuf.ByteString;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.IdentityKeyPair;
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPrivateKey;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+import org.whispersystems.libaxolotl.kdf.HKDF;
+import org.whispersystems.libaxolotl.ratchet.ChainKey;
+import org.whispersystems.libaxolotl.ratchet.MessageKeys;
+import org.whispersystems.libaxolotl.ratchet.RootKey;
+import org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain;
+import org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange;
+import org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey;
+import org.whispersystems.libaxolotl.util.Pair;
+import org.whispersystems.libaxolotl.util.guava.Optional;
+
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+import static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure;
+
+public class SessionState {
+
+  private SessionStructure sessionStructure;
+
+  public SessionState() {
+    this.sessionStructure = SessionStructure.newBuilder().build();
+  }
+
+  public SessionState(SessionStructure sessionStructure) {
+    this.sessionStructure = sessionStructure;
+  }
+
+  public SessionState(SessionState copy) {
+    this.sessionStructure = copy.sessionStructure.toBuilder().build();
+  }
+
+  public SessionStructure getStructure() {
+    return sessionStructure;
+  }
+
+  public byte[] getAliceBaseKey() {
+    return this.sessionStructure.getAliceBaseKey().toByteArray();
+  }
+
+  public void setAliceBaseKey(byte[] aliceBaseKey) {
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setAliceBaseKey(ByteString.copyFrom(aliceBaseKey))
+                                                 .build();
+  }
+
+  public void setSessionVersion(int version) {
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setSessionVersion(version)
+                                                 .build();
+  }
+
+  public int getSessionVersion() {
+    int sessionVersion = this.sessionStructure.getSessionVersion();
+
+    if (sessionVersion == 0) return 2;
+    else                     return sessionVersion;
+  }
+
+  public void setRemoteIdentityKey(IdentityKey identityKey) {
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setRemoteIdentityPublic(ByteString.copyFrom(identityKey.serialize()))
+                                                 .build();
+  }
+
+  public void setLocalIdentityKey(IdentityKey identityKey) {
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setLocalIdentityPublic(ByteString.copyFrom(identityKey.serialize()))
+                                                 .build();
+  }
+
+  public IdentityKey getRemoteIdentityKey() {
+    try {
+      if (!this.sessionStructure.hasRemoteIdentityPublic()) {
+        return null;
+      }
+
+      return new IdentityKey(this.sessionStructure.getRemoteIdentityPublic().toByteArray(), 0);
+    } catch (InvalidKeyException e) {
+      Log.w("SessionRecordV2", e);
+      return null;
+    }
+  }
+
+  public IdentityKey getLocalIdentityKey() {
+    try {
+      return new IdentityKey(this.sessionStructure.getLocalIdentityPublic().toByteArray(), 0);
+    } catch (InvalidKeyException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public int getPreviousCounter() {
+    return sessionStructure.getPreviousCounter();
+  }
+
+  public void setPreviousCounter(int previousCounter) {
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setPreviousCounter(previousCounter)
+                                                 .build();
+  }
+
+  public RootKey getRootKey() {
+    return new RootKey(HKDF.createFor(getSessionVersion()),
+                       this.sessionStructure.getRootKey().toByteArray());
+  }
+
+  public void setRootKey(RootKey rootKey) {
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setRootKey(ByteString.copyFrom(rootKey.getKeyBytes()))
+                                                 .build();
+  }
+
+  public ECPublicKey getSenderRatchetKey() {
+    try {
+      return Curve.decodePoint(sessionStructure.getSenderChain().getSenderRatchetKey().toByteArray(), 0);
+    } catch (InvalidKeyException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public ECKeyPair getSenderRatchetKeyPair() {
+    ECPublicKey  publicKey  = getSenderRatchetKey();
+    ECPrivateKey privateKey = Curve.decodePrivatePoint(sessionStructure.getSenderChain()
+                                                                       .getSenderRatchetKeyPrivate()
+                                                                       .toByteArray());
+
+    return new ECKeyPair(publicKey, privateKey);
+  }
+
+  public boolean hasReceiverChain(ECPublicKey senderEphemeral) {
+    return getReceiverChain(senderEphemeral) != null;
+  }
+
+  public boolean hasSenderChain() {
+    return sessionStructure.hasSenderChain();
+  }
+
+  private Pair<Chain,Integer> getReceiverChain(ECPublicKey senderEphemeral) {
+    List<Chain> receiverChains = sessionStructure.getReceiverChainsList();
+    int         index          = 0;
+
+    for (Chain receiverChain : receiverChains) {
+      try {
+        ECPublicKey chainSenderRatchetKey = Curve.decodePoint(receiverChain.getSenderRatchetKey().toByteArray(), 0);
+
+        if (chainSenderRatchetKey.equals(senderEphemeral)) {
+          return new Pair<>(receiverChain,index);
+        }
+      } catch (InvalidKeyException e) {
+        Log.w("SessionRecordV2", e);
+      }
+
+      index++;
+    }
+
+    return null;
+  }
+
+  public ChainKey getReceiverChainKey(ECPublicKey senderEphemeral) {
+    Pair<Chain,Integer> receiverChainAndIndex = getReceiverChain(senderEphemeral);
+    Chain               receiverChain         = receiverChainAndIndex.first();
+
+    if (receiverChain == null) {
+      return null;
+    } else {
+      return new ChainKey(HKDF.createFor(getSessionVersion()),
+                          receiverChain.getChainKey().getKey().toByteArray(),
+                          receiverChain.getChainKey().getIndex());
+    }
+  }
+
+  public void addReceiverChain(ECPublicKey senderRatchetKey, ChainKey chainKey) {
+    Chain.ChainKey chainKeyStructure = Chain.ChainKey.newBuilder()
+                                                     .setKey(ByteString.copyFrom(chainKey.getKey()))
+                                                     .setIndex(chainKey.getIndex())
+                                                     .build();
+
+    Chain chain = Chain.newBuilder()
+                       .setChainKey(chainKeyStructure)
+                       .setSenderRatchetKey(ByteString.copyFrom(senderRatchetKey.serialize()))
+                       .build();
+
+    this.sessionStructure = this.sessionStructure.toBuilder().addReceiverChains(chain).build();
+
+    if (this.sessionStructure.getReceiverChainsList().size() > 5) {
+      this.sessionStructure = this.sessionStructure.toBuilder()
+                                                   .removeReceiverChains(0)
+                                                   .build();
+    }
+  }
+
+  public void setSenderChain(ECKeyPair senderRatchetKeyPair, ChainKey chainKey) {
+    Chain.ChainKey chainKeyStructure = Chain.ChainKey.newBuilder()
+                                                     .setKey(ByteString.copyFrom(chainKey.getKey()))
+                                                     .setIndex(chainKey.getIndex())
+                                                     .build();
+
+    Chain senderChain = Chain.newBuilder()
+                             .setSenderRatchetKey(ByteString.copyFrom(senderRatchetKeyPair.getPublicKey().serialize()))
+                             .setSenderRatchetKeyPrivate(ByteString.copyFrom(senderRatchetKeyPair.getPrivateKey().serialize()))
+                             .setChainKey(chainKeyStructure)
+                             .build();
+
+    this.sessionStructure = this.sessionStructure.toBuilder().setSenderChain(senderChain).build();
+  }
+
+  public ChainKey getSenderChainKey() {
+    Chain.ChainKey chainKeyStructure = sessionStructure.getSenderChain().getChainKey();
+    return new ChainKey(HKDF.createFor(getSessionVersion()),
+                        chainKeyStructure.getKey().toByteArray(), chainKeyStructure.getIndex());
+  }
+
+
+  public void setSenderChainKey(ChainKey nextChainKey) {
+    Chain.ChainKey chainKey = Chain.ChainKey.newBuilder()
+                                            .setKey(ByteString.copyFrom(nextChainKey.getKey()))
+                                            .setIndex(nextChainKey.getIndex())
+                                            .build();
+
+    Chain chain = sessionStructure.getSenderChain().toBuilder()
+                                  .setChainKey(chainKey).build();
+
+    this.sessionStructure = this.sessionStructure.toBuilder().setSenderChain(chain).build();
+  }
+
+  public boolean hasMessageKeys(ECPublicKey senderEphemeral, int counter) {
+    Pair<Chain,Integer> chainAndIndex = getReceiverChain(senderEphemeral);
+    Chain               chain         = chainAndIndex.first();
+
+    if (chain == null) {
+      return false;
+    }
+
+    List<Chain.MessageKey> messageKeyList = chain.getMessageKeysList();
+
+    for (Chain.MessageKey messageKey : messageKeyList) {
+      if (messageKey.getIndex() == counter) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+  public MessageKeys removeMessageKeys(ECPublicKey senderEphemeral, int counter) {
+    Pair<Chain,Integer> chainAndIndex = getReceiverChain(senderEphemeral);
+    Chain               chain         = chainAndIndex.first();
+
+    if (chain == null) {
+      return null;
+    }
+
+    List<Chain.MessageKey>     messageKeyList     = new LinkedList<>(chain.getMessageKeysList());
+    Iterator<Chain.MessageKey> messageKeyIterator = messageKeyList.iterator();
+    MessageKeys                result             = null;
+
+    while (messageKeyIterator.hasNext()) {
+      Chain.MessageKey messageKey = messageKeyIterator.next();
+
+      if (messageKey.getIndex() == counter) {
+        result = new MessageKeys(new SecretKeySpec(messageKey.getCipherKey().toByteArray(), "AES"),
+                                 new SecretKeySpec(messageKey.getMacKey().toByteArray(), "HmacSHA256"),
+                                 new IvParameterSpec(messageKey.getIv().toByteArray()),
+                                 messageKey.getIndex());
+
+        messageKeyIterator.remove();
+        break;
+      }
+    }
+
+    Chain updatedChain = chain.toBuilder().clearMessageKeys()
+                              .addAllMessageKeys(messageKeyList)
+                              .build();
+
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setReceiverChains(chainAndIndex.second(), updatedChain)
+                                                 .build();
+
+    return result;
+  }
+
+  public void setMessageKeys(ECPublicKey senderEphemeral, MessageKeys messageKeys) {
+    Pair<Chain,Integer> chainAndIndex       = getReceiverChain(senderEphemeral);
+    Chain               chain               = chainAndIndex.first();
+    Chain.MessageKey    messageKeyStructure = Chain.MessageKey.newBuilder()
+                                                              .setCipherKey(ByteString.copyFrom(messageKeys.getCipherKey().getEncoded()))
+                                                              .setMacKey(ByteString.copyFrom(messageKeys.getMacKey().getEncoded()))
+                                                              .setIndex(messageKeys.getCounter())
+                                                              .setIv(ByteString.copyFrom(messageKeys.getIv().getIV()))
+                                                              .build();
+
+    Chain updatedChain = chain.toBuilder()
+                              .addMessageKeys(messageKeyStructure)
+                              .build();
+
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setReceiverChains(chainAndIndex.second(), updatedChain)
+                                                 .build();
+  }
+
+  public void setReceiverChainKey(ECPublicKey senderEphemeral, ChainKey chainKey) {
+    Pair<Chain,Integer> chainAndIndex = getReceiverChain(senderEphemeral);
+    Chain               chain         = chainAndIndex.first();
+
+    Chain.ChainKey chainKeyStructure = Chain.ChainKey.newBuilder()
+                                                     .setKey(ByteString.copyFrom(chainKey.getKey()))
+                                                     .setIndex(chainKey.getIndex())
+                                                     .build();
+
+    Chain updatedChain = chain.toBuilder().setChainKey(chainKeyStructure).build();
+
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setReceiverChains(chainAndIndex.second(), updatedChain)
+                                                 .build();
+  }
+
+  public void setPendingKeyExchange(int sequence,
+                                    ECKeyPair ourBaseKey,
+                                    ECKeyPair ourRatchetKey,
+                                    IdentityKeyPair ourIdentityKey)
+  {
+    PendingKeyExchange structure =
+        PendingKeyExchange.newBuilder()
+                          .setSequence(sequence)
+                          .setLocalBaseKey(ByteString.copyFrom(ourBaseKey.getPublicKey().serialize()))
+                          .setLocalBaseKeyPrivate(ByteString.copyFrom(ourBaseKey.getPrivateKey().serialize()))
+                          .setLocalRatchetKey(ByteString.copyFrom(ourRatchetKey.getPublicKey().serialize()))
+                          .setLocalRatchetKeyPrivate(ByteString.copyFrom(ourRatchetKey.getPrivateKey().serialize()))
+                          .setLocalIdentityKey(ByteString.copyFrom(ourIdentityKey.getPublicKey().serialize()))
+                          .setLocalIdentityKeyPrivate(ByteString.copyFrom(ourIdentityKey.getPrivateKey().serialize()))
+                          .build();
+
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setPendingKeyExchange(structure)
+                                                 .build();
+  }
+
+  public int getPendingKeyExchangeSequence() {
+    return sessionStructure.getPendingKeyExchange().getSequence();
+  }
+
+  public ECKeyPair getPendingKeyExchangeBaseKey() throws InvalidKeyException {
+    ECPublicKey publicKey   = Curve.decodePoint(sessionStructure.getPendingKeyExchange()
+                                                                .getLocalBaseKey().toByteArray(), 0);
+
+    ECPrivateKey privateKey = Curve.decodePrivatePoint(sessionStructure.getPendingKeyExchange()
+                                                                       .getLocalBaseKeyPrivate()
+                                                                       .toByteArray());
+
+    return new ECKeyPair(publicKey, privateKey);
+  }
+
+  public ECKeyPair getPendingKeyExchangeRatchetKey() throws InvalidKeyException {
+    ECPublicKey publicKey   = Curve.decodePoint(sessionStructure.getPendingKeyExchange()
+                                                                .getLocalRatchetKey().toByteArray(), 0);
+
+    ECPrivateKey privateKey = Curve.decodePrivatePoint(sessionStructure.getPendingKeyExchange()
+                                                                       .getLocalRatchetKeyPrivate()
+                                                                       .toByteArray());
+
+    return new ECKeyPair(publicKey, privateKey);
+  }
+
+  public IdentityKeyPair getPendingKeyExchangeIdentityKey() throws InvalidKeyException {
+    IdentityKey publicKey = new IdentityKey(sessionStructure.getPendingKeyExchange()
+                                                            .getLocalIdentityKey().toByteArray(), 0);
+
+    ECPrivateKey privateKey = Curve.decodePrivatePoint(sessionStructure.getPendingKeyExchange()
+                                                                       .getLocalIdentityKeyPrivate()
+                                                                       .toByteArray());
+
+    return new IdentityKeyPair(publicKey, privateKey);
+  }
+
+  public boolean hasPendingKeyExchange() {
+    return sessionStructure.hasPendingKeyExchange();
+  }
+
+  public void setUnacknowledgedPreKeyMessage(Optional<Integer> preKeyId, int signedPreKeyId, ECPublicKey baseKey) {
+    PendingPreKey.Builder pending = PendingPreKey.newBuilder()
+                                                 .setSignedPreKeyId(signedPreKeyId)
+                                                 .setBaseKey(ByteString.copyFrom(baseKey.serialize()));
+
+    if (preKeyId.isPresent()) {
+      pending.setPreKeyId(preKeyId.get());
+    }
+
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setPendingPreKey(pending.build())
+                                                 .build();
+  }
+
+  public boolean hasUnacknowledgedPreKeyMessage() {
+    return this.sessionStructure.hasPendingPreKey();
+  }
+
+  public UnacknowledgedPreKeyMessageItems getUnacknowledgedPreKeyMessageItems() {
+    try {
+      Optional<Integer> preKeyId;
+
+      if (sessionStructure.getPendingPreKey().hasPreKeyId()) {
+        preKeyId = Optional.of(sessionStructure.getPendingPreKey().getPreKeyId());
+      } else {
+        preKeyId = Optional.absent();
+      }
+
+      return
+          new UnacknowledgedPreKeyMessageItems(preKeyId,
+                                               sessionStructure.getPendingPreKey().getSignedPreKeyId(),
+                                               Curve.decodePoint(sessionStructure.getPendingPreKey()
+                                                                                 .getBaseKey()
+                                                                                 .toByteArray(), 0));
+    } catch (InvalidKeyException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public void clearUnacknowledgedPreKeyMessage() {
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .clearPendingPreKey()
+                                                 .build();
+  }
+
+  public void setRemoteRegistrationId(int registrationId) {
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setRemoteRegistrationId(registrationId)
+                                                 .build();
+  }
+
+  public int getRemoteRegistrationId() {
+    return this.sessionStructure.getRemoteRegistrationId();
+  }
+
+  public void setLocalRegistrationId(int registrationId) {
+    this.sessionStructure = this.sessionStructure.toBuilder()
+                                                 .setLocalRegistrationId(registrationId)
+                                                 .build();
+  }
+
+  public int getLocalRegistrationId() {
+    return this.sessionStructure.getLocalRegistrationId();
+  }
+
+  public byte[] serialize() {
+    return sessionStructure.toByteArray();
+  }
+
+  public static class UnacknowledgedPreKeyMessageItems {
+    private final Optional<Integer> preKeyId;
+    private final int               signedPreKeyId;
+    private final ECPublicKey       baseKey;
+
+    public UnacknowledgedPreKeyMessageItems(Optional<Integer> preKeyId,
+                                            int signedPreKeyId,
+                                            ECPublicKey baseKey)
+    {
+      this.preKeyId       = preKeyId;
+      this.signedPreKeyId = signedPreKeyId;
+      this.baseKey        = baseKey;
+    }
+
+
+    public Optional<Integer> getPreKeyId() {
+      return preKeyId;
+    }
+
+    public int getSignedPreKeyId() {
+      return signedPreKeyId;
+    }
+
+    public ECPublicKey getBaseKey() {
+      return baseKey;
+    }
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/state/SessionStore.java b/src/main/java/org/whispersystems/libaxolotl/state/SessionStore.java
new file mode 100644
index 00000000..c5ad00b0
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/state/SessionStore.java
@@ -0,0 +1,68 @@
+package org.whispersystems.libaxolotl.state;
+
+import java.util.List;
+
+/**
+ * The interface to the durable store of session state information
+ * for remote clients.
+ *
+ * @author Moxie Marlinspike
+ */
+public interface SessionStore {
+
+  /**
+   * Returns a copy of the {@link SessionRecord} corresponding to the recipientId + deviceId tuple,
+   * or a new SessionRecord if one does not currently exist.
+   * <p>
+   * It is important that implementations return a copy of the current durable information.  The
+   * returned SessionRecord may be modified, but those changes should not have an effect on the
+   * durable session state (what is returned by subsequent calls to this method) without the
+   * store method being called here first.
+   *
+   * @param recipientId The recipientID of the remote client.
+   * @param deviceId The deviceID of the remote client.
+   * @return a copy of the SessionRecord corresponding to the recipientId + deviceId tuple, or
+   *         a new SessionRecord if one does not currently exist.
+   */
+  public SessionRecord loadSession(long recipientId, int deviceId);
+
+  /**
+   * Returns all known devices with active sessions for a recipient
+   *
+   * @param recipientId the recipient ID.
+   * @return all known sub-devices with active sessions.
+   */
+  public List<Integer> getSubDeviceSessions(long recipientId);
+
+  /**
+   * Commit to storage the {@link SessionRecord} for a given recipientId + deviceId tuple.
+   * @param recipientId the recipient ID of the remote client.
+   * @param deviceId the device ID of the remote client.
+   * @param record the current SessionRecord for the remote client.
+   */
+  public void storeSession(long recipientId, int deviceId, SessionRecord record);
+
+  /**
+   * Determine whether there is a committed {@link SessionRecord} for a recipientId + deviceId tuple.
+   * @param recipientId the recipient ID of the remote client.
+   * @param deviceId the device ID of the remote client.
+   * @return true if a {@link SessionRecord} exists, false otherwise.
+   */
+  public boolean containsSession(long recipientId, int deviceId);
+
+  /**
+   * Remove a {@link SessionRecord} for a recipientId + deviceId tuple.
+   *
+   * @param recipientId the recipient ID of the remote client.
+   * @param deviceId the device ID of the remote client.
+   */
+  public void deleteSession(long recipientId, int deviceId);
+
+  /**
+   * Remove the {@link SessionRecord}s corresponding to all devices of a recipientId.
+   *
+   * @param recipientId the recipient ID of the remote client.
+   */
+  public void deleteAllSessions(long recipientId);
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/state/SignedPreKeyRecord.java b/src/main/java/org/whispersystems/libaxolotl/state/SignedPreKeyRecord.java
new file mode 100644
index 00000000..f11f5cf1
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/state/SignedPreKeyRecord.java
@@ -0,0 +1,61 @@
+package org.whispersystems.libaxolotl.state;
+
+import com.google.protobuf.ByteString;
+
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.ecc.ECPrivateKey;
+import org.whispersystems.libaxolotl.ecc.ECPublicKey;
+
+import java.io.IOException;
+
+import static org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure;
+
+public class SignedPreKeyRecord {
+
+  private SignedPreKeyRecordStructure structure;
+
+  public SignedPreKeyRecord(int id, long timestamp, ECKeyPair keyPair, byte[] signature) {
+    this.structure = SignedPreKeyRecordStructure.newBuilder()
+                                                .setId(id)
+                                                .setPublicKey(ByteString.copyFrom(keyPair.getPublicKey()
+                                                                                         .serialize()))
+                                                .setPrivateKey(ByteString.copyFrom(keyPair.getPrivateKey()
+                                                                                          .serialize()))
+                                                .setSignature(ByteString.copyFrom(signature))
+                                                .setTimestamp(timestamp)
+                                                .build();
+  }
+
+  public SignedPreKeyRecord(byte[] serialized) throws IOException {
+    this.structure = SignedPreKeyRecordStructure.parseFrom(serialized);
+  }
+
+  public int getId() {
+    return this.structure.getId();
+  }
+
+  public long getTimestamp() {
+    return this.structure.getTimestamp();
+  }
+
+  public ECKeyPair getKeyPair() {
+    try {
+      ECPublicKey publicKey = Curve.decodePoint(this.structure.getPublicKey().toByteArray(), 0);
+      ECPrivateKey privateKey = Curve.decodePrivatePoint(this.structure.getPrivateKey().toByteArray());
+
+      return new ECKeyPair(publicKey, privateKey);
+    } catch (InvalidKeyException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public byte[] getSignature() {
+    return this.structure.getSignature().toByteArray();
+  }
+
+  public byte[] serialize() {
+    return this.structure.toByteArray();
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/state/SignedPreKeyStore.java b/src/main/java/org/whispersystems/libaxolotl/state/SignedPreKeyStore.java
new file mode 100644
index 00000000..c828bf23
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/state/SignedPreKeyStore.java
@@ -0,0 +1,47 @@
+package org.whispersystems.libaxolotl.state;
+
+import org.whispersystems.libaxolotl.InvalidKeyIdException;
+
+import java.util.List;
+
+public interface SignedPreKeyStore {
+
+
+  /**
+   * Load a local SignedPreKeyRecord.
+   *
+   * @param signedPreKeyId the ID of the local SignedPreKeyRecord.
+   * @return the corresponding SignedPreKeyRecord.
+   * @throws InvalidKeyIdException when there is no corresponding SignedPreKeyRecord.
+   */
+  public SignedPreKeyRecord loadSignedPreKey(int signedPreKeyId) throws InvalidKeyIdException;
+
+  /**
+   * Load all local SignedPreKeyRecords.
+   *
+   * @return All stored SignedPreKeyRecords.
+   */
+  public List<SignedPreKeyRecord> loadSignedPreKeys();
+
+  /**
+   * Store a local SignedPreKeyRecord.
+   *
+   * @param signedPreKeyId the ID of the SignedPreKeyRecord to store.
+   * @param record the SignedPreKeyRecord.
+   */
+  public void         storeSignedPreKey(int signedPreKeyId, SignedPreKeyRecord record);
+
+  /**
+   * @param signedPreKeyId A SignedPreKeyRecord ID.
+   * @return true if the store has a record for the signedPreKeyId, otherwise false.
+   */
+  public boolean      containsSignedPreKey(int signedPreKeyId);
+
+  /**
+   * Delete a SignedPreKeyRecord from local storage.
+   *
+   * @param signedPreKeyId The ID of the SignedPreKeyRecord to remove.
+   */
+  public void         removeSignedPreKey(int signedPreKeyId);
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/state/StorageProtos.java b/src/main/java/org/whispersystems/libaxolotl/state/StorageProtos.java
new file mode 100644
index 00000000..b3e3e0e6
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/state/StorageProtos.java
@@ -0,0 +1,11779 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: LocalStorageProtocol.proto
+
+package org.whispersystems.libaxolotl.state;
+
+public final class StorageProtos {
+  private StorageProtos() {}
+  public static void registerAllExtensions(
+      com.google.protobuf.ExtensionRegistry registry) {
+  }
+  public interface SessionStructureOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional uint32 sessionVersion = 1;
+    /**
+     * <code>optional uint32 sessionVersion = 1;</code>
+     */
+    boolean hasSessionVersion();
+    /**
+     * <code>optional uint32 sessionVersion = 1;</code>
+     */
+    int getSessionVersion();
+
+    // optional bytes localIdentityPublic = 2;
+    /**
+     * <code>optional bytes localIdentityPublic = 2;</code>
+     */
+    boolean hasLocalIdentityPublic();
+    /**
+     * <code>optional bytes localIdentityPublic = 2;</code>
+     */
+    com.google.protobuf.ByteString getLocalIdentityPublic();
+
+    // optional bytes remoteIdentityPublic = 3;
+    /**
+     * <code>optional bytes remoteIdentityPublic = 3;</code>
+     */
+    boolean hasRemoteIdentityPublic();
+    /**
+     * <code>optional bytes remoteIdentityPublic = 3;</code>
+     */
+    com.google.protobuf.ByteString getRemoteIdentityPublic();
+
+    // optional bytes rootKey = 4;
+    /**
+     * <code>optional bytes rootKey = 4;</code>
+     */
+    boolean hasRootKey();
+    /**
+     * <code>optional bytes rootKey = 4;</code>
+     */
+    com.google.protobuf.ByteString getRootKey();
+
+    // optional uint32 previousCounter = 5;
+    /**
+     * <code>optional uint32 previousCounter = 5;</code>
+     */
+    boolean hasPreviousCounter();
+    /**
+     * <code>optional uint32 previousCounter = 5;</code>
+     */
+    int getPreviousCounter();
+
+    // optional .textsecure.SessionStructure.Chain senderChain = 6;
+    /**
+     * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+     */
+    boolean hasSenderChain();
+    /**
+     * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain getSenderChain();
+    /**
+     * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder getSenderChainOrBuilder();
+
+    // repeated .textsecure.SessionStructure.Chain receiverChains = 7;
+    /**
+     * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+     */
+    java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain> 
+        getReceiverChainsList();
+    /**
+     * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain getReceiverChains(int index);
+    /**
+     * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+     */
+    int getReceiverChainsCount();
+    /**
+     * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+     */
+    java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder> 
+        getReceiverChainsOrBuilderList();
+    /**
+     * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder getReceiverChainsOrBuilder(
+        int index);
+
+    // optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+     */
+    boolean hasPendingKeyExchange();
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange getPendingKeyExchange();
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchangeOrBuilder getPendingKeyExchangeOrBuilder();
+
+    // optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+     */
+    boolean hasPendingPreKey();
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey getPendingPreKey();
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKeyOrBuilder getPendingPreKeyOrBuilder();
+
+    // optional uint32 remoteRegistrationId = 10;
+    /**
+     * <code>optional uint32 remoteRegistrationId = 10;</code>
+     */
+    boolean hasRemoteRegistrationId();
+    /**
+     * <code>optional uint32 remoteRegistrationId = 10;</code>
+     */
+    int getRemoteRegistrationId();
+
+    // optional uint32 localRegistrationId = 11;
+    /**
+     * <code>optional uint32 localRegistrationId = 11;</code>
+     */
+    boolean hasLocalRegistrationId();
+    /**
+     * <code>optional uint32 localRegistrationId = 11;</code>
+     */
+    int getLocalRegistrationId();
+
+    // optional bool needsRefresh = 12;
+    /**
+     * <code>optional bool needsRefresh = 12;</code>
+     */
+    boolean hasNeedsRefresh();
+    /**
+     * <code>optional bool needsRefresh = 12;</code>
+     */
+    boolean getNeedsRefresh();
+
+    // optional bytes aliceBaseKey = 13;
+    /**
+     * <code>optional bytes aliceBaseKey = 13;</code>
+     */
+    boolean hasAliceBaseKey();
+    /**
+     * <code>optional bytes aliceBaseKey = 13;</code>
+     */
+    com.google.protobuf.ByteString getAliceBaseKey();
+  }
+  /**
+   * Protobuf type {@code textsecure.SessionStructure}
+   */
+  public static final class SessionStructure extends
+      com.google.protobuf.GeneratedMessage
+      implements SessionStructureOrBuilder {
+    // Use SessionStructure.newBuilder() to construct.
+    private SessionStructure(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private SessionStructure(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final SessionStructure defaultInstance;
+    public static SessionStructure getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public SessionStructure getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private SessionStructure(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 8: {
+              bitField0_ |= 0x00000001;
+              sessionVersion_ = input.readUInt32();
+              break;
+            }
+            case 18: {
+              bitField0_ |= 0x00000002;
+              localIdentityPublic_ = input.readBytes();
+              break;
+            }
+            case 26: {
+              bitField0_ |= 0x00000004;
+              remoteIdentityPublic_ = input.readBytes();
+              break;
+            }
+            case 34: {
+              bitField0_ |= 0x00000008;
+              rootKey_ = input.readBytes();
+              break;
+            }
+            case 40: {
+              bitField0_ |= 0x00000010;
+              previousCounter_ = input.readUInt32();
+              break;
+            }
+            case 50: {
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder subBuilder = null;
+              if (((bitField0_ & 0x00000020) == 0x00000020)) {
+                subBuilder = senderChain_.toBuilder();
+              }
+              senderChain_ = input.readMessage(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.PARSER, extensionRegistry);
+              if (subBuilder != null) {
+                subBuilder.mergeFrom(senderChain_);
+                senderChain_ = subBuilder.buildPartial();
+              }
+              bitField0_ |= 0x00000020;
+              break;
+            }
+            case 58: {
+              if (!((mutable_bitField0_ & 0x00000040) == 0x00000040)) {
+                receiverChains_ = new java.util.ArrayList<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain>();
+                mutable_bitField0_ |= 0x00000040;
+              }
+              receiverChains_.add(input.readMessage(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.PARSER, extensionRegistry));
+              break;
+            }
+            case 66: {
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.Builder subBuilder = null;
+              if (((bitField0_ & 0x00000040) == 0x00000040)) {
+                subBuilder = pendingKeyExchange_.toBuilder();
+              }
+              pendingKeyExchange_ = input.readMessage(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.PARSER, extensionRegistry);
+              if (subBuilder != null) {
+                subBuilder.mergeFrom(pendingKeyExchange_);
+                pendingKeyExchange_ = subBuilder.buildPartial();
+              }
+              bitField0_ |= 0x00000040;
+              break;
+            }
+            case 74: {
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.Builder subBuilder = null;
+              if (((bitField0_ & 0x00000080) == 0x00000080)) {
+                subBuilder = pendingPreKey_.toBuilder();
+              }
+              pendingPreKey_ = input.readMessage(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.PARSER, extensionRegistry);
+              if (subBuilder != null) {
+                subBuilder.mergeFrom(pendingPreKey_);
+                pendingPreKey_ = subBuilder.buildPartial();
+              }
+              bitField0_ |= 0x00000080;
+              break;
+            }
+            case 80: {
+              bitField0_ |= 0x00000100;
+              remoteRegistrationId_ = input.readUInt32();
+              break;
+            }
+            case 88: {
+              bitField0_ |= 0x00000200;
+              localRegistrationId_ = input.readUInt32();
+              break;
+            }
+            case 96: {
+              bitField0_ |= 0x00000400;
+              needsRefresh_ = input.readBool();
+              break;
+            }
+            case 106: {
+              bitField0_ |= 0x00000800;
+              aliceBaseKey_ = input.readBytes();
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        if (((mutable_bitField0_ & 0x00000040) == 0x00000040)) {
+          receiverChains_ = java.util.Collections.unmodifiableList(receiverChains_);
+        }
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<SessionStructure> PARSER =
+        new com.google.protobuf.AbstractParser<SessionStructure>() {
+      public SessionStructure parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new SessionStructure(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<SessionStructure> getParserForType() {
+      return PARSER;
+    }
+
+    public interface ChainOrBuilder
+        extends com.google.protobuf.MessageOrBuilder {
+
+      // optional bytes senderRatchetKey = 1;
+      /**
+       * <code>optional bytes senderRatchetKey = 1;</code>
+       */
+      boolean hasSenderRatchetKey();
+      /**
+       * <code>optional bytes senderRatchetKey = 1;</code>
+       */
+      com.google.protobuf.ByteString getSenderRatchetKey();
+
+      // optional bytes senderRatchetKeyPrivate = 2;
+      /**
+       * <code>optional bytes senderRatchetKeyPrivate = 2;</code>
+       */
+      boolean hasSenderRatchetKeyPrivate();
+      /**
+       * <code>optional bytes senderRatchetKeyPrivate = 2;</code>
+       */
+      com.google.protobuf.ByteString getSenderRatchetKeyPrivate();
+
+      // optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+       */
+      boolean hasChainKey();
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+       */
+      org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey getChainKey();
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+       */
+      org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKeyOrBuilder getChainKeyOrBuilder();
+
+      // repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+       */
+      java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey> 
+          getMessageKeysList();
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+       */
+      org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey getMessageKeys(int index);
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+       */
+      int getMessageKeysCount();
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+       */
+      java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKeyOrBuilder> 
+          getMessageKeysOrBuilderList();
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+       */
+      org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKeyOrBuilder getMessageKeysOrBuilder(
+          int index);
+    }
+    /**
+     * Protobuf type {@code textsecure.SessionStructure.Chain}
+     */
+    public static final class Chain extends
+        com.google.protobuf.GeneratedMessage
+        implements ChainOrBuilder {
+      // Use Chain.newBuilder() to construct.
+      private Chain(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+        super(builder);
+        this.unknownFields = builder.getUnknownFields();
+      }
+      private Chain(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+      private static final Chain defaultInstance;
+      public static Chain getDefaultInstance() {
+        return defaultInstance;
+      }
+
+      public Chain getDefaultInstanceForType() {
+        return defaultInstance;
+      }
+
+      private final com.google.protobuf.UnknownFieldSet unknownFields;
+      @java.lang.Override
+      public final com.google.protobuf.UnknownFieldSet
+          getUnknownFields() {
+        return this.unknownFields;
+      }
+      private Chain(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        initFields();
+        int mutable_bitField0_ = 0;
+        com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+            com.google.protobuf.UnknownFieldSet.newBuilder();
+        try {
+          boolean done = false;
+          while (!done) {
+            int tag = input.readTag();
+            switch (tag) {
+              case 0:
+                done = true;
+                break;
+              default: {
+                if (!parseUnknownField(input, unknownFields,
+                                       extensionRegistry, tag)) {
+                  done = true;
+                }
+                break;
+              }
+              case 10: {
+                bitField0_ |= 0x00000001;
+                senderRatchetKey_ = input.readBytes();
+                break;
+              }
+              case 18: {
+                bitField0_ |= 0x00000002;
+                senderRatchetKeyPrivate_ = input.readBytes();
+                break;
+              }
+              case 26: {
+                org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.Builder subBuilder = null;
+                if (((bitField0_ & 0x00000004) == 0x00000004)) {
+                  subBuilder = chainKey_.toBuilder();
+                }
+                chainKey_ = input.readMessage(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.PARSER, extensionRegistry);
+                if (subBuilder != null) {
+                  subBuilder.mergeFrom(chainKey_);
+                  chainKey_ = subBuilder.buildPartial();
+                }
+                bitField0_ |= 0x00000004;
+                break;
+              }
+              case 34: {
+                if (!((mutable_bitField0_ & 0x00000008) == 0x00000008)) {
+                  messageKeys_ = new java.util.ArrayList<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey>();
+                  mutable_bitField0_ |= 0x00000008;
+                }
+                messageKeys_.add(input.readMessage(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.PARSER, extensionRegistry));
+                break;
+              }
+            }
+          }
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          throw e.setUnfinishedMessage(this);
+        } catch (java.io.IOException e) {
+          throw new com.google.protobuf.InvalidProtocolBufferException(
+              e.getMessage()).setUnfinishedMessage(this);
+        } finally {
+          if (((mutable_bitField0_ & 0x00000008) == 0x00000008)) {
+            messageKeys_ = java.util.Collections.unmodifiableList(messageKeys_);
+          }
+          this.unknownFields = unknownFields.build();
+          makeExtensionsImmutable();
+        }
+      }
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder.class);
+      }
+
+      public static com.google.protobuf.Parser<Chain> PARSER =
+          new com.google.protobuf.AbstractParser<Chain>() {
+        public Chain parsePartialFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return new Chain(input, extensionRegistry);
+        }
+      };
+
+      @java.lang.Override
+      public com.google.protobuf.Parser<Chain> getParserForType() {
+        return PARSER;
+      }
+
+      public interface ChainKeyOrBuilder
+          extends com.google.protobuf.MessageOrBuilder {
+
+        // optional uint32 index = 1;
+        /**
+         * <code>optional uint32 index = 1;</code>
+         */
+        boolean hasIndex();
+        /**
+         * <code>optional uint32 index = 1;</code>
+         */
+        int getIndex();
+
+        // optional bytes key = 2;
+        /**
+         * <code>optional bytes key = 2;</code>
+         */
+        boolean hasKey();
+        /**
+         * <code>optional bytes key = 2;</code>
+         */
+        com.google.protobuf.ByteString getKey();
+      }
+      /**
+       * Protobuf type {@code textsecure.SessionStructure.Chain.ChainKey}
+       */
+      public static final class ChainKey extends
+          com.google.protobuf.GeneratedMessage
+          implements ChainKeyOrBuilder {
+        // Use ChainKey.newBuilder() to construct.
+        private ChainKey(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+          super(builder);
+          this.unknownFields = builder.getUnknownFields();
+        }
+        private ChainKey(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+        private static final ChainKey defaultInstance;
+        public static ChainKey getDefaultInstance() {
+          return defaultInstance;
+        }
+
+        public ChainKey getDefaultInstanceForType() {
+          return defaultInstance;
+        }
+
+        private final com.google.protobuf.UnknownFieldSet unknownFields;
+        @java.lang.Override
+        public final com.google.protobuf.UnknownFieldSet
+            getUnknownFields() {
+          return this.unknownFields;
+        }
+        private ChainKey(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          initFields();
+          int mutable_bitField0_ = 0;
+          com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+              com.google.protobuf.UnknownFieldSet.newBuilder();
+          try {
+            boolean done = false;
+            while (!done) {
+              int tag = input.readTag();
+              switch (tag) {
+                case 0:
+                  done = true;
+                  break;
+                default: {
+                  if (!parseUnknownField(input, unknownFields,
+                                         extensionRegistry, tag)) {
+                    done = true;
+                  }
+                  break;
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+                case 8: {
+                  bitField0_ |= 0x00000001;
+                  index_ = input.readUInt32();
+                  break;
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+                case 18: {
+                  bitField0_ |= 0x00000002;
+                  key_ = input.readBytes();
+                  break;
+                }
+              }
+            }
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(this);
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(
+                e.getMessage()).setUnfinishedMessage(this);
+          } finally {
+            this.unknownFields = unknownFields.build();
+            makeExtensionsImmutable();
+          }
+        }
+        public static final com.google.protobuf.Descriptors.Descriptor
+            getDescriptor() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_ChainKey_descriptor;
+        }
+
+        protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+            internalGetFieldAccessorTable() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_ChainKey_fieldAccessorTable
+              .ensureFieldAccessorsInitialized(
+                  org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.Builder.class);
+        }
+
+        public static com.google.protobuf.Parser<ChainKey> PARSER =
+            new com.google.protobuf.AbstractParser<ChainKey>() {
+          public ChainKey parsePartialFrom(
+              com.google.protobuf.CodedInputStream input,
+              com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+              throws com.google.protobuf.InvalidProtocolBufferException {
+            return new ChainKey(input, extensionRegistry);
+          }
+        };
+
+        @java.lang.Override
+        public com.google.protobuf.Parser<ChainKey> getParserForType() {
+          return PARSER;
+        }
+
+        private int bitField0_;
+        // optional uint32 index = 1;
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+        private int index_;
+        /**
+         * <code>optional uint32 index = 1;</code>
+         */
+        public boolean hasIndex() {
+          return ((bitField0_ & 0x00000001) == 0x00000001);
+        }
+        /**
+         * <code>optional uint32 index = 1;</code>
+         */
+        public int getIndex() {
+          return index_;
+        }
+
+        // optional bytes key = 2;
+        public static final int KEY_FIELD_NUMBER = 2;
+        private com.google.protobuf.ByteString key_;
+        /**
+         * <code>optional bytes key = 2;</code>
+         */
+        public boolean hasKey() {
+          return ((bitField0_ & 0x00000002) == 0x00000002);
+        }
+        /**
+         * <code>optional bytes key = 2;</code>
+         */
+        public com.google.protobuf.ByteString getKey() {
+          return key_;
+        }
+
+        private void initFields() {
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+          key_ = com.google.protobuf.ByteString.EMPTY;
+        }
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+
+          memoizedIsInitialized = 1;
+          return true;
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+
+        public void writeTo(com.google.protobuf.CodedOutputStream output)
+                            throws java.io.IOException {
+          getSerializedSize();
+          if (((bitField0_ & 0x00000001) == 0x00000001)) {
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+          if (((bitField0_ & 0x00000002) == 0x00000002)) {
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+        }
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+          memoizedSerializedSize = size;
+          return size;
+        }
+
+        private static final long serialVersionUID = 0L;
+        @java.lang.Override
+        protected java.lang.Object writeReplace()
+            throws java.io.ObjectStreamException {
+          return super.writeReplace();
+        }
+
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey parseFrom(
+            com.google.protobuf.ByteString data)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return PARSER.parseFrom(data);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey parseFrom(
+            com.google.protobuf.ByteString data,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return PARSER.parseFrom(data, extensionRegistry);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey parseFrom(byte[] data)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return PARSER.parseFrom(data);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey parseFrom(
+            byte[] data,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return PARSER.parseFrom(data, extensionRegistry);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey parseFrom(java.io.InputStream input)
+            throws java.io.IOException {
+          return PARSER.parseFrom(input);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey parseFrom(
+            java.io.InputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          return PARSER.parseFrom(input, extensionRegistry);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey parseDelimitedFrom(java.io.InputStream input)
+            throws java.io.IOException {
+          return PARSER.parseDelimitedFrom(input);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey parseDelimitedFrom(
+            java.io.InputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          return PARSER.parseDelimitedFrom(input, extensionRegistry);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey parseFrom(
+            com.google.protobuf.CodedInputStream input)
+            throws java.io.IOException {
+          return PARSER.parseFrom(input);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey parseFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          return PARSER.parseFrom(input, extensionRegistry);
+        }
+
+        public static Builder newBuilder() { return Builder.create(); }
+        public Builder newBuilderForType() { return newBuilder(); }
+        public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey prototype) {
+          return newBuilder().mergeFrom(prototype);
+        }
+        public Builder toBuilder() { return newBuilder(this); }
+
+        @java.lang.Override
+        protected Builder newBuilderForType(
+            com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+          Builder builder = new Builder(parent);
+          return builder;
+        }
+        /**
+         * Protobuf type {@code textsecure.SessionStructure.Chain.ChainKey}
+         */
+        public static final class Builder extends
+            com.google.protobuf.GeneratedMessage.Builder<Builder>
+           implements org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKeyOrBuilder {
+          public static final com.google.protobuf.Descriptors.Descriptor
+              getDescriptor() {
+            return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_ChainKey_descriptor;
+          }
+
+          protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+              internalGetFieldAccessorTable() {
+            return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_ChainKey_fieldAccessorTable
+                .ensureFieldAccessorsInitialized(
+                    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.Builder.class);
+          }
+
+          // Construct using org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.newBuilder()
+          private Builder() {
+            maybeForceBuilderInitialization();
+          }
+
+          private Builder(
+              com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+            super(parent);
+            maybeForceBuilderInitialization();
+          }
+          private void maybeForceBuilderInitialization() {
+            if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+            }
+          }
+          private static Builder create() {
+            return new Builder();
+          }
+
+          public Builder clear() {
+            super.clear();
+            index_ = 0;
+            bitField0_ = (bitField0_ & ~0x00000001);
+            key_ = com.google.protobuf.ByteString.EMPTY;
+            bitField0_ = (bitField0_ & ~0x00000002);
+            return this;
+          }
+
+          public Builder clone() {
+            return create().mergeFrom(buildPartial());
+          }
+
+          public com.google.protobuf.Descriptors.Descriptor
+              getDescriptorForType() {
+            return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_ChainKey_descriptor;
+          }
+
+          public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey getDefaultInstanceForType() {
+            return org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.getDefaultInstance();
+          }
+
+          public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey build() {
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey result = buildPartial();
+            if (!result.isInitialized()) {
+              throw newUninitializedMessageException(result);
+            }
+            return result;
+          }
+
+          public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey buildPartial() {
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey result = new org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey(this);
+            int from_bitField0_ = bitField0_;
+            int to_bitField0_ = 0;
+            if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+              to_bitField0_ |= 0x00000001;
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+            result.index_ = index_;
+            if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+              to_bitField0_ |= 0x00000002;
+            }
+            result.key_ = key_;
+            result.bitField0_ = to_bitField0_;
+            onBuilt();
+            return result;
+          }
+
+          public Builder mergeFrom(com.google.protobuf.Message other) {
+            if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey) {
+              return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey)other);
+            } else {
+              super.mergeFrom(other);
+              return this;
+            }
+          }
+
+          public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey other) {
+            if (other == org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.getDefaultInstance()) return this;
+            if (other.hasIndex()) {
+              setIndex(other.getIndex());
+            }
+            if (other.hasKey()) {
+              setKey(other.getKey());
+            }
+            this.mergeUnknownFields(other.getUnknownFields());
+            return this;
+          }
+
+          public final boolean isInitialized() {
+            return true;
+          }
+
+          public Builder mergeFrom(
+              com.google.protobuf.CodedInputStream input,
+              com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+              throws java.io.IOException {
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey parsedMessage = null;
+            try {
+              parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+            } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+              parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey) e.getUnfinishedMessage();
+              throw e;
+            } finally {
+              if (parsedMessage != null) {
+                mergeFrom(parsedMessage);
+              }
+            }
+            return this;
+          }
+          private int bitField0_;
+
+          // optional uint32 index = 1;
+          private int index_ ;
+          /**
+           * <code>optional uint32 index = 1;</code>
+           */
+          public boolean hasIndex() {
+            return ((bitField0_ & 0x00000001) == 0x00000001);
+          }
+          /**
+           * <code>optional uint32 index = 1;</code>
+           */
+          public int getIndex() {
+            return index_;
+          }
+          /**
+           * <code>optional uint32 index = 1;</code>
+           */
+          public Builder setIndex(int value) {
+            bitField0_ |= 0x00000001;
+            index_ = value;
+            onChanged();
+            return this;
+          }
+          /**
+           * <code>optional uint32 index = 1;</code>
+           */
+          public Builder clearIndex() {
+            bitField0_ = (bitField0_ & ~0x00000001);
+            index_ = 0;
+            onChanged();
+            return this;
+          }
+
+          // optional bytes key = 2;
+          private com.google.protobuf.ByteString key_ = com.google.protobuf.ByteString.EMPTY;
+          /**
+           * <code>optional bytes key = 2;</code>
+           */
+          public boolean hasKey() {
+            return ((bitField0_ & 0x00000002) == 0x00000002);
+          }
+          /**
+           * <code>optional bytes key = 2;</code>
+           */
+          public com.google.protobuf.ByteString getKey() {
+            return key_;
+          }
+          /**
+           * <code>optional bytes key = 2;</code>
+           */
+          public Builder setKey(com.google.protobuf.ByteString value) {
+            if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+            key_ = value;
+            onChanged();
+            return this;
+          }
+          /**
+           * <code>optional bytes key = 2;</code>
+           */
+          public Builder clearKey() {
+            bitField0_ = (bitField0_ & ~0x00000002);
+            key_ = getDefaultInstance().getKey();
+            onChanged();
+            return this;
+          }
+
+          // @@protoc_insertion_point(builder_scope:textsecure.SessionStructure.Chain.ChainKey)
+        }
+
+        static {
+          defaultInstance = new ChainKey(true);
+          defaultInstance.initFields();
+        }
+
+        // @@protoc_insertion_point(class_scope:textsecure.SessionStructure.Chain.ChainKey)
+      }
+
+      public interface MessageKeyOrBuilder
+          extends com.google.protobuf.MessageOrBuilder {
+
+        // optional uint32 index = 1;
+        /**
+         * <code>optional uint32 index = 1;</code>
+         */
+        boolean hasIndex();
+        /**
+         * <code>optional uint32 index = 1;</code>
+         */
+        int getIndex();
+
+        // optional bytes cipherKey = 2;
+        /**
+         * <code>optional bytes cipherKey = 2;</code>
+         */
+        boolean hasCipherKey();
+        /**
+         * <code>optional bytes cipherKey = 2;</code>
+         */
+        com.google.protobuf.ByteString getCipherKey();
+
+        // optional bytes macKey = 3;
+        /**
+         * <code>optional bytes macKey = 3;</code>
+         */
+        boolean hasMacKey();
+        /**
+         * <code>optional bytes macKey = 3;</code>
+         */
+        com.google.protobuf.ByteString getMacKey();
+
+        // optional bytes iv = 4;
+        /**
+         * <code>optional bytes iv = 4;</code>
+         */
+        boolean hasIv();
+        /**
+         * <code>optional bytes iv = 4;</code>
+         */
+        com.google.protobuf.ByteString getIv();
+      }
+      /**
+       * Protobuf type {@code textsecure.SessionStructure.Chain.MessageKey}
+       */
+      public static final class MessageKey extends
+          com.google.protobuf.GeneratedMessage
+          implements MessageKeyOrBuilder {
+        // Use MessageKey.newBuilder() to construct.
+        private MessageKey(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+          super(builder);
+          this.unknownFields = builder.getUnknownFields();
+        }
+        private MessageKey(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+        private static final MessageKey defaultInstance;
+        public static MessageKey getDefaultInstance() {
+          return defaultInstance;
+        }
+
+        public MessageKey getDefaultInstanceForType() {
+          return defaultInstance;
+        }
+
+        private final com.google.protobuf.UnknownFieldSet unknownFields;
+        @java.lang.Override
+        public final com.google.protobuf.UnknownFieldSet
+            getUnknownFields() {
+          return this.unknownFields;
+        }
+        private MessageKey(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          initFields();
+          int mutable_bitField0_ = 0;
+          com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+              com.google.protobuf.UnknownFieldSet.newBuilder();
+          try {
+            boolean done = false;
+            while (!done) {
+              int tag = input.readTag();
+              switch (tag) {
+                case 0:
+                  done = true;
+                  break;
+                default: {
+                  if (!parseUnknownField(input, unknownFields,
+                                         extensionRegistry, tag)) {
+                    done = true;
+                  }
+                  break;
+                }
+                case 8: {
+                  bitField0_ |= 0x00000001;
+                  index_ = input.readUInt32();
+                  break;
+                }
+                case 18: {
+                  bitField0_ |= 0x00000002;
+                  cipherKey_ = input.readBytes();
+                  break;
+                }
+                case 26: {
+                  bitField0_ |= 0x00000004;
+                  macKey_ = input.readBytes();
+                  break;
+                }
+                case 34: {
+                  bitField0_ |= 0x00000008;
+                  iv_ = input.readBytes();
+                  break;
+                }
+              }
+            }
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(this);
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(
+                e.getMessage()).setUnfinishedMessage(this);
+          } finally {
+            this.unknownFields = unknownFields.build();
+            makeExtensionsImmutable();
+          }
+        }
+        public static final com.google.protobuf.Descriptors.Descriptor
+            getDescriptor() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_MessageKey_descriptor;
+        }
+
+        protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+            internalGetFieldAccessorTable() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_MessageKey_fieldAccessorTable
+              .ensureFieldAccessorsInitialized(
+                  org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder.class);
+        }
+
+        public static com.google.protobuf.Parser<MessageKey> PARSER =
+            new com.google.protobuf.AbstractParser<MessageKey>() {
+          public MessageKey parsePartialFrom(
+              com.google.protobuf.CodedInputStream input,
+              com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+              throws com.google.protobuf.InvalidProtocolBufferException {
+            return new MessageKey(input, extensionRegistry);
+          }
+        };
+
+        @java.lang.Override
+        public com.google.protobuf.Parser<MessageKey> getParserForType() {
+          return PARSER;
+        }
+
+        private int bitField0_;
+        // optional uint32 index = 1;
+        public static final int INDEX_FIELD_NUMBER = 1;
+        private int index_;
+        /**
+         * <code>optional uint32 index = 1;</code>
+         */
+        public boolean hasIndex() {
+          return ((bitField0_ & 0x00000001) == 0x00000001);
+        }
+        /**
+         * <code>optional uint32 index = 1;</code>
+         */
+        public int getIndex() {
+          return index_;
+        }
+
+        // optional bytes cipherKey = 2;
+        public static final int CIPHERKEY_FIELD_NUMBER = 2;
+        private com.google.protobuf.ByteString cipherKey_;
+        /**
+         * <code>optional bytes cipherKey = 2;</code>
+         */
+        public boolean hasCipherKey() {
+          return ((bitField0_ & 0x00000002) == 0x00000002);
+        }
+        /**
+         * <code>optional bytes cipherKey = 2;</code>
+         */
+        public com.google.protobuf.ByteString getCipherKey() {
+          return cipherKey_;
+        }
+
+        // optional bytes macKey = 3;
+        public static final int MACKEY_FIELD_NUMBER = 3;
+        private com.google.protobuf.ByteString macKey_;
+        /**
+         * <code>optional bytes macKey = 3;</code>
+         */
+        public boolean hasMacKey() {
+          return ((bitField0_ & 0x00000004) == 0x00000004);
+        }
+        /**
+         * <code>optional bytes macKey = 3;</code>
+         */
+        public com.google.protobuf.ByteString getMacKey() {
+          return macKey_;
+        }
+
+        // optional bytes iv = 4;
+        public static final int IV_FIELD_NUMBER = 4;
+        private com.google.protobuf.ByteString iv_;
+        /**
+         * <code>optional bytes iv = 4;</code>
+         */
+        public boolean hasIv() {
+          return ((bitField0_ & 0x00000008) == 0x00000008);
+        }
+        /**
+         * <code>optional bytes iv = 4;</code>
+         */
+        public com.google.protobuf.ByteString getIv() {
+          return iv_;
+        }
+
+        private void initFields() {
+          index_ = 0;
+          cipherKey_ = com.google.protobuf.ByteString.EMPTY;
+          macKey_ = com.google.protobuf.ByteString.EMPTY;
+          iv_ = com.google.protobuf.ByteString.EMPTY;
+        }
+        private byte memoizedIsInitialized = -1;
+        public final boolean isInitialized() {
+          byte isInitialized = memoizedIsInitialized;
+          if (isInitialized != -1) return isInitialized == 1;
+
+          memoizedIsInitialized = 1;
+          return true;
+        }
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+        public void writeTo(com.google.protobuf.CodedOutputStream output)
+                            throws java.io.IOException {
+          getSerializedSize();
+          if (((bitField0_ & 0x00000001) == 0x00000001)) {
+            output.writeUInt32(1, index_);
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+          if (((bitField0_ & 0x00000002) == 0x00000002)) {
+            output.writeBytes(2, cipherKey_);
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+          if (((bitField0_ & 0x00000004) == 0x00000004)) {
+            output.writeBytes(3, macKey_);
+          }
+          if (((bitField0_ & 0x00000008) == 0x00000008)) {
+            output.writeBytes(4, iv_);
+          }
+          getUnknownFields().writeTo(output);
+        }
+
+        private int memoizedSerializedSize = -1;
+        public int getSerializedSize() {
+          int size = memoizedSerializedSize;
+          if (size != -1) return size;
+
+          size = 0;
+          if (((bitField0_ & 0x00000001) == 0x00000001)) {
+            size += com.google.protobuf.CodedOutputStream
+              .computeUInt32Size(1, index_);
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+          if (((bitField0_ & 0x00000002) == 0x00000002)) {
+            size += com.google.protobuf.CodedOutputStream
+              .computeBytesSize(2, cipherKey_);
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+          if (((bitField0_ & 0x00000004) == 0x00000004)) {
+            size += com.google.protobuf.CodedOutputStream
+              .computeBytesSize(3, macKey_);
+          }
+          if (((bitField0_ & 0x00000008) == 0x00000008)) {
+            size += com.google.protobuf.CodedOutputStream
+              .computeBytesSize(4, iv_);
+          }
+          size += getUnknownFields().getSerializedSize();
+          memoizedSerializedSize = size;
+          return size;
+        }
+
+        private static final long serialVersionUID = 0L;
+        @java.lang.Override
+        protected java.lang.Object writeReplace()
+            throws java.io.ObjectStreamException {
+          return super.writeReplace();
+        }
+
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey parseFrom(
+            com.google.protobuf.ByteString data)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return PARSER.parseFrom(data);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey parseFrom(
+            com.google.protobuf.ByteString data,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return PARSER.parseFrom(data, extensionRegistry);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey parseFrom(byte[] data)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return PARSER.parseFrom(data);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey parseFrom(
+            byte[] data,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return PARSER.parseFrom(data, extensionRegistry);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey parseFrom(java.io.InputStream input)
+            throws java.io.IOException {
+          return PARSER.parseFrom(input);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey parseFrom(
+            java.io.InputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          return PARSER.parseFrom(input, extensionRegistry);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey parseDelimitedFrom(java.io.InputStream input)
+            throws java.io.IOException {
+          return PARSER.parseDelimitedFrom(input);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey parseDelimitedFrom(
+            java.io.InputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          return PARSER.parseDelimitedFrom(input, extensionRegistry);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey parseFrom(
+            com.google.protobuf.CodedInputStream input)
+            throws java.io.IOException {
+          return PARSER.parseFrom(input);
+        }
+        public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey parseFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          return PARSER.parseFrom(input, extensionRegistry);
+        }
+
+        public static Builder newBuilder() { return Builder.create(); }
+        public Builder newBuilderForType() { return newBuilder(); }
+        public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey prototype) {
+          return newBuilder().mergeFrom(prototype);
+        }
+        public Builder toBuilder() { return newBuilder(this); }
+
+        @java.lang.Override
+        protected Builder newBuilderForType(
+            com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+          Builder builder = new Builder(parent);
+          return builder;
+        }
+        /**
+         * Protobuf type {@code textsecure.SessionStructure.Chain.MessageKey}
+         */
+        public static final class Builder extends
+            com.google.protobuf.GeneratedMessage.Builder<Builder>
+           implements org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKeyOrBuilder {
+          public static final com.google.protobuf.Descriptors.Descriptor
+              getDescriptor() {
+            return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_MessageKey_descriptor;
+          }
+
+          protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+              internalGetFieldAccessorTable() {
+            return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_MessageKey_fieldAccessorTable
+                .ensureFieldAccessorsInitialized(
+                    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder.class);
+          }
+
+          // Construct using org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.newBuilder()
+          private Builder() {
+            maybeForceBuilderInitialization();
+          }
+
+          private Builder(
+              com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+            super(parent);
+            maybeForceBuilderInitialization();
+          }
+          private void maybeForceBuilderInitialization() {
+            if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+            }
+          }
+          private static Builder create() {
+            return new Builder();
+          }
+
+          public Builder clear() {
+            super.clear();
+            index_ = 0;
+            bitField0_ = (bitField0_ & ~0x00000001);
+            cipherKey_ = com.google.protobuf.ByteString.EMPTY;
+            bitField0_ = (bitField0_ & ~0x00000002);
+            macKey_ = com.google.protobuf.ByteString.EMPTY;
+            bitField0_ = (bitField0_ & ~0x00000004);
+            iv_ = com.google.protobuf.ByteString.EMPTY;
+            bitField0_ = (bitField0_ & ~0x00000008);
+            return this;
+          }
+
+          public Builder clone() {
+            return create().mergeFrom(buildPartial());
+          }
+
+          public com.google.protobuf.Descriptors.Descriptor
+              getDescriptorForType() {
+            return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_MessageKey_descriptor;
+          }
+
+          public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey getDefaultInstanceForType() {
+            return org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.getDefaultInstance();
+          }
+
+          public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey build() {
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey result = buildPartial();
+            if (!result.isInitialized()) {
+              throw newUninitializedMessageException(result);
+            }
+            return result;
+          }
+
+          public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey buildPartial() {
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey result = new org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey(this);
+            int from_bitField0_ = bitField0_;
+            int to_bitField0_ = 0;
+            if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+              to_bitField0_ |= 0x00000001;
+            }
+            result.index_ = index_;
+            if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+              to_bitField0_ |= 0x00000002;
+            }
+            result.cipherKey_ = cipherKey_;
+            if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+              to_bitField0_ |= 0x00000004;
+            }
+            result.macKey_ = macKey_;
+            if (((from_bitField0_ & 0x00000008) == 0x00000008)) {
+              to_bitField0_ |= 0x00000008;
+            }
+            result.iv_ = iv_;
+            result.bitField0_ = to_bitField0_;
+            onBuilt();
+            return result;
+          }
+
+          public Builder mergeFrom(com.google.protobuf.Message other) {
+            if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey) {
+              return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey)other);
+            } else {
+              super.mergeFrom(other);
+              return this;
+            }
+          }
+
+          public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey other) {
+            if (other == org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.getDefaultInstance()) return this;
+            if (other.hasIndex()) {
+              setIndex(other.getIndex());
+            }
+            if (other.hasCipherKey()) {
+              setCipherKey(other.getCipherKey());
+            }
+            if (other.hasMacKey()) {
+              setMacKey(other.getMacKey());
+            }
+            if (other.hasIv()) {
+              setIv(other.getIv());
+            }
+            this.mergeUnknownFields(other.getUnknownFields());
+            return this;
+          }
+
+          public final boolean isInitialized() {
+            return true;
+          }
+
+          public Builder mergeFrom(
+              com.google.protobuf.CodedInputStream input,
+              com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+              throws java.io.IOException {
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey parsedMessage = null;
+            try {
+              parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+            } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+              parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey) e.getUnfinishedMessage();
+              throw e;
+            } finally {
+              if (parsedMessage != null) {
+                mergeFrom(parsedMessage);
+              }
+            }
+            return this;
+          }
+          private int bitField0_;
+
+          // optional uint32 index = 1;
+          private int index_ ;
+          /**
+           * <code>optional uint32 index = 1;</code>
+           */
+          public boolean hasIndex() {
+            return ((bitField0_ & 0x00000001) == 0x00000001);
+          }
+          /**
+           * <code>optional uint32 index = 1;</code>
+           */
+          public int getIndex() {
+            return index_;
+          }
+          /**
+           * <code>optional uint32 index = 1;</code>
+           */
+          public Builder setIndex(int value) {
+            bitField0_ |= 0x00000001;
+            index_ = value;
+            onChanged();
+            return this;
+          }
+          /**
+           * <code>optional uint32 index = 1;</code>
+           */
+          public Builder clearIndex() {
+            bitField0_ = (bitField0_ & ~0x00000001);
+            index_ = 0;
+            onChanged();
+            return this;
+          }
+
+          // optional bytes cipherKey = 2;
+          private com.google.protobuf.ByteString cipherKey_ = com.google.protobuf.ByteString.EMPTY;
+          /**
+           * <code>optional bytes cipherKey = 2;</code>
+           */
+          public boolean hasCipherKey() {
+            return ((bitField0_ & 0x00000002) == 0x00000002);
+          }
+          /**
+           * <code>optional bytes cipherKey = 2;</code>
+           */
+          public com.google.protobuf.ByteString getCipherKey() {
+            return cipherKey_;
+          }
+          /**
+           * <code>optional bytes cipherKey = 2;</code>
+           */
+          public Builder setCipherKey(com.google.protobuf.ByteString value) {
+            if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+            cipherKey_ = value;
+            onChanged();
+            return this;
+          }
+          /**
+           * <code>optional bytes cipherKey = 2;</code>
+           */
+          public Builder clearCipherKey() {
+            bitField0_ = (bitField0_ & ~0x00000002);
+            cipherKey_ = getDefaultInstance().getCipherKey();
+            onChanged();
+            return this;
+          }
+
+          // optional bytes macKey = 3;
+          private com.google.protobuf.ByteString macKey_ = com.google.protobuf.ByteString.EMPTY;
+          /**
+           * <code>optional bytes macKey = 3;</code>
+           */
+          public boolean hasMacKey() {
+            return ((bitField0_ & 0x00000004) == 0x00000004);
+          }
+          /**
+           * <code>optional bytes macKey = 3;</code>
+           */
+          public com.google.protobuf.ByteString getMacKey() {
+            return macKey_;
+          }
+          /**
+           * <code>optional bytes macKey = 3;</code>
+           */
+          public Builder setMacKey(com.google.protobuf.ByteString value) {
+            if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000004;
+            macKey_ = value;
+            onChanged();
+            return this;
+          }
+          /**
+           * <code>optional bytes macKey = 3;</code>
+           */
+          public Builder clearMacKey() {
+            bitField0_ = (bitField0_ & ~0x00000004);
+            macKey_ = getDefaultInstance().getMacKey();
+            onChanged();
+            return this;
+          }
+
+          // optional bytes iv = 4;
+          private com.google.protobuf.ByteString iv_ = com.google.protobuf.ByteString.EMPTY;
+          /**
+           * <code>optional bytes iv = 4;</code>
+           */
+          public boolean hasIv() {
+            return ((bitField0_ & 0x00000008) == 0x00000008);
+          }
+          /**
+           * <code>optional bytes iv = 4;</code>
+           */
+          public com.google.protobuf.ByteString getIv() {
+            return iv_;
+          }
+          /**
+           * <code>optional bytes iv = 4;</code>
+           */
+          public Builder setIv(com.google.protobuf.ByteString value) {
+            if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000008;
+            iv_ = value;
+            onChanged();
+            return this;
+          }
+          /**
+           * <code>optional bytes iv = 4;</code>
+           */
+          public Builder clearIv() {
+            bitField0_ = (bitField0_ & ~0x00000008);
+            iv_ = getDefaultInstance().getIv();
+            onChanged();
+            return this;
+          }
+
+          // @@protoc_insertion_point(builder_scope:textsecure.SessionStructure.Chain.MessageKey)
+        }
+
+        static {
+          defaultInstance = new MessageKey(true);
+          defaultInstance.initFields();
+        }
+
+        // @@protoc_insertion_point(class_scope:textsecure.SessionStructure.Chain.MessageKey)
+      }
+
+      private int bitField0_;
+      // optional bytes senderRatchetKey = 1;
+      public static final int SENDERRATCHETKEY_FIELD_NUMBER = 1;
+      private com.google.protobuf.ByteString senderRatchetKey_;
+      /**
+       * <code>optional bytes senderRatchetKey = 1;</code>
+       */
+      public boolean hasSenderRatchetKey() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional bytes senderRatchetKey = 1;</code>
+       */
+      public com.google.protobuf.ByteString getSenderRatchetKey() {
+        return senderRatchetKey_;
+      }
+
+      // optional bytes senderRatchetKeyPrivate = 2;
+      public static final int SENDERRATCHETKEYPRIVATE_FIELD_NUMBER = 2;
+      private com.google.protobuf.ByteString senderRatchetKeyPrivate_;
+      /**
+       * <code>optional bytes senderRatchetKeyPrivate = 2;</code>
+       */
+      public boolean hasSenderRatchetKeyPrivate() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional bytes senderRatchetKeyPrivate = 2;</code>
+       */
+      public com.google.protobuf.ByteString getSenderRatchetKeyPrivate() {
+        return senderRatchetKeyPrivate_;
+      }
+
+      // optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;
+      public static final int CHAINKEY_FIELD_NUMBER = 3;
+      private org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey chainKey_;
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+       */
+      public boolean hasChainKey() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey getChainKey() {
+        return chainKey_;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKeyOrBuilder getChainKeyOrBuilder() {
+        return chainKey_;
+      }
+
+      // repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;
+      public static final int MESSAGEKEYS_FIELD_NUMBER = 4;
+      private java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey> messageKeys_;
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+       */
+      public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey> getMessageKeysList() {
+        return messageKeys_;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+       */
+      public java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKeyOrBuilder> 
+          getMessageKeysOrBuilderList() {
+        return messageKeys_;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+       */
+      public int getMessageKeysCount() {
+        return messageKeys_.size();
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey getMessageKeys(int index) {
+        return messageKeys_.get(index);
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKeyOrBuilder getMessageKeysOrBuilder(
+          int index) {
+        return messageKeys_.get(index);
+      }
+
+      private void initFields() {
+        senderRatchetKey_ = com.google.protobuf.ByteString.EMPTY;
+        senderRatchetKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+        chainKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.getDefaultInstance();
+        messageKeys_ = java.util.Collections.emptyList();
+      }
+      private byte memoizedIsInitialized = -1;
+      public final boolean isInitialized() {
+        byte isInitialized = memoizedIsInitialized;
+        if (isInitialized != -1) return isInitialized == 1;
+
+        memoizedIsInitialized = 1;
+        return true;
+      }
+
+      public void writeTo(com.google.protobuf.CodedOutputStream output)
+                          throws java.io.IOException {
+        getSerializedSize();
+        if (((bitField0_ & 0x00000001) == 0x00000001)) {
+          output.writeBytes(1, senderRatchetKey_);
+        }
+        if (((bitField0_ & 0x00000002) == 0x00000002)) {
+          output.writeBytes(2, senderRatchetKeyPrivate_);
+        }
+        if (((bitField0_ & 0x00000004) == 0x00000004)) {
+          output.writeMessage(3, chainKey_);
+        }
+        for (int i = 0; i < messageKeys_.size(); i++) {
+          output.writeMessage(4, messageKeys_.get(i));
+        }
+        getUnknownFields().writeTo(output);
+      }
+
+      private int memoizedSerializedSize = -1;
+      public int getSerializedSize() {
+        int size = memoizedSerializedSize;
+        if (size != -1) return size;
+
+        size = 0;
+        if (((bitField0_ & 0x00000001) == 0x00000001)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeBytesSize(1, senderRatchetKey_);
+        }
+        if (((bitField0_ & 0x00000002) == 0x00000002)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeBytesSize(2, senderRatchetKeyPrivate_);
+        }
+        if (((bitField0_ & 0x00000004) == 0x00000004)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeMessageSize(3, chainKey_);
+        }
+        for (int i = 0; i < messageKeys_.size(); i++) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeMessageSize(4, messageKeys_.get(i));
+        }
+        size += getUnknownFields().getSerializedSize();
+        memoizedSerializedSize = size;
+        return size;
+      }
+
+      private static final long serialVersionUID = 0L;
+      @java.lang.Override
+      protected java.lang.Object writeReplace()
+          throws java.io.ObjectStreamException {
+        return super.writeReplace();
+      }
+
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain parseFrom(
+          com.google.protobuf.ByteString data)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain parseFrom(
+          com.google.protobuf.ByteString data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain parseFrom(byte[] data)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain parseFrom(
+          byte[] data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain parseFrom(java.io.InputStream input)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain parseFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain parseDelimitedFrom(java.io.InputStream input)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain parseDelimitedFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain parseFrom(
+          com.google.protobuf.CodedInputStream input)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain parseFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
+      }
+
+      public static Builder newBuilder() { return Builder.create(); }
+      public Builder newBuilderForType() { return newBuilder(); }
+      public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain prototype) {
+        return newBuilder().mergeFrom(prototype);
+      }
+      public Builder toBuilder() { return newBuilder(this); }
+
+      @java.lang.Override
+      protected Builder newBuilderForType(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        Builder builder = new Builder(parent);
+        return builder;
+      }
+      /**
+       * Protobuf type {@code textsecure.SessionStructure.Chain}
+       */
+      public static final class Builder extends
+          com.google.protobuf.GeneratedMessage.Builder<Builder>
+         implements org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder {
+        public static final com.google.protobuf.Descriptors.Descriptor
+            getDescriptor() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_descriptor;
+        }
+
+        protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+            internalGetFieldAccessorTable() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_fieldAccessorTable
+              .ensureFieldAccessorsInitialized(
+                  org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder.class);
+        }
+
+        // Construct using org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.newBuilder()
+        private Builder() {
+          maybeForceBuilderInitialization();
+        }
+
+        private Builder(
+            com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+          super(parent);
+          maybeForceBuilderInitialization();
+        }
+        private void maybeForceBuilderInitialization() {
+          if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+            getChainKeyFieldBuilder();
+            getMessageKeysFieldBuilder();
+          }
+        }
+        private static Builder create() {
+          return new Builder();
+        }
+
+        public Builder clear() {
+          super.clear();
+          senderRatchetKey_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000001);
+          senderRatchetKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000002);
+          if (chainKeyBuilder_ == null) {
+            chainKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.getDefaultInstance();
+          } else {
+            chainKeyBuilder_.clear();
+          }
+          bitField0_ = (bitField0_ & ~0x00000004);
+          if (messageKeysBuilder_ == null) {
+            messageKeys_ = java.util.Collections.emptyList();
+            bitField0_ = (bitField0_ & ~0x00000008);
+          } else {
+            messageKeysBuilder_.clear();
+          }
+          return this;
+        }
+
+        public Builder clone() {
+          return create().mergeFrom(buildPartial());
+        }
+
+        public com.google.protobuf.Descriptors.Descriptor
+            getDescriptorForType() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_Chain_descriptor;
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain getDefaultInstanceForType() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.getDefaultInstance();
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain build() {
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain result = buildPartial();
+          if (!result.isInitialized()) {
+            throw newUninitializedMessageException(result);
+          }
+          return result;
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain buildPartial() {
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain result = new org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain(this);
+          int from_bitField0_ = bitField0_;
+          int to_bitField0_ = 0;
+          if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+            to_bitField0_ |= 0x00000001;
+          }
+          result.senderRatchetKey_ = senderRatchetKey_;
+          if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+            to_bitField0_ |= 0x00000002;
+          }
+          result.senderRatchetKeyPrivate_ = senderRatchetKeyPrivate_;
+          if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+            to_bitField0_ |= 0x00000004;
+          }
+          if (chainKeyBuilder_ == null) {
+            result.chainKey_ = chainKey_;
+          } else {
+            result.chainKey_ = chainKeyBuilder_.build();
+          }
+          if (messageKeysBuilder_ == null) {
+            if (((bitField0_ & 0x00000008) == 0x00000008)) {
+              messageKeys_ = java.util.Collections.unmodifiableList(messageKeys_);
+              bitField0_ = (bitField0_ & ~0x00000008);
+            }
+            result.messageKeys_ = messageKeys_;
+          } else {
+            result.messageKeys_ = messageKeysBuilder_.build();
+          }
+          result.bitField0_ = to_bitField0_;
+          onBuilt();
+          return result;
+        }
+
+        public Builder mergeFrom(com.google.protobuf.Message other) {
+          if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain) {
+            return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain)other);
+          } else {
+            super.mergeFrom(other);
+            return this;
+          }
+        }
+
+        public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain other) {
+          if (other == org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.getDefaultInstance()) return this;
+          if (other.hasSenderRatchetKey()) {
+            setSenderRatchetKey(other.getSenderRatchetKey());
+          }
+          if (other.hasSenderRatchetKeyPrivate()) {
+            setSenderRatchetKeyPrivate(other.getSenderRatchetKeyPrivate());
+          }
+          if (other.hasChainKey()) {
+            mergeChainKey(other.getChainKey());
+          }
+          if (messageKeysBuilder_ == null) {
+            if (!other.messageKeys_.isEmpty()) {
+              if (messageKeys_.isEmpty()) {
+                messageKeys_ = other.messageKeys_;
+                bitField0_ = (bitField0_ & ~0x00000008);
+              } else {
+                ensureMessageKeysIsMutable();
+                messageKeys_.addAll(other.messageKeys_);
+              }
+              onChanged();
+            }
+          } else {
+            if (!other.messageKeys_.isEmpty()) {
+              if (messageKeysBuilder_.isEmpty()) {
+                messageKeysBuilder_.dispose();
+                messageKeysBuilder_ = null;
+                messageKeys_ = other.messageKeys_;
+                bitField0_ = (bitField0_ & ~0x00000008);
+                messageKeysBuilder_ = 
+                  com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders ?
+                     getMessageKeysFieldBuilder() : null;
+              } else {
+                messageKeysBuilder_.addAllMessages(other.messageKeys_);
+              }
+            }
+          }
+          this.mergeUnknownFields(other.getUnknownFields());
+          return this;
+        }
+
+        public final boolean isInitialized() {
+          return true;
+        }
+
+        public Builder mergeFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain parsedMessage = null;
+          try {
+            parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain) e.getUnfinishedMessage();
+            throw e;
+          } finally {
+            if (parsedMessage != null) {
+              mergeFrom(parsedMessage);
+            }
+          }
+          return this;
+        }
+        private int bitField0_;
+
+        // optional bytes senderRatchetKey = 1;
+        private com.google.protobuf.ByteString senderRatchetKey_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes senderRatchetKey = 1;</code>
+         */
+        public boolean hasSenderRatchetKey() {
+          return ((bitField0_ & 0x00000001) == 0x00000001);
+        }
+        /**
+         * <code>optional bytes senderRatchetKey = 1;</code>
+         */
+        public com.google.protobuf.ByteString getSenderRatchetKey() {
+          return senderRatchetKey_;
+        }
+        /**
+         * <code>optional bytes senderRatchetKey = 1;</code>
+         */
+        public Builder setSenderRatchetKey(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000001;
+          senderRatchetKey_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes senderRatchetKey = 1;</code>
+         */
+        public Builder clearSenderRatchetKey() {
+          bitField0_ = (bitField0_ & ~0x00000001);
+          senderRatchetKey_ = getDefaultInstance().getSenderRatchetKey();
+          onChanged();
+          return this;
+        }
+
+        // optional bytes senderRatchetKeyPrivate = 2;
+        private com.google.protobuf.ByteString senderRatchetKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes senderRatchetKeyPrivate = 2;</code>
+         */
+        public boolean hasSenderRatchetKeyPrivate() {
+          return ((bitField0_ & 0x00000002) == 0x00000002);
+        }
+        /**
+         * <code>optional bytes senderRatchetKeyPrivate = 2;</code>
+         */
+        public com.google.protobuf.ByteString getSenderRatchetKeyPrivate() {
+          return senderRatchetKeyPrivate_;
+        }
+        /**
+         * <code>optional bytes senderRatchetKeyPrivate = 2;</code>
+         */
+        public Builder setSenderRatchetKeyPrivate(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+          senderRatchetKeyPrivate_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes senderRatchetKeyPrivate = 2;</code>
+         */
+        public Builder clearSenderRatchetKeyPrivate() {
+          bitField0_ = (bitField0_ & ~0x00000002);
+          senderRatchetKeyPrivate_ = getDefaultInstance().getSenderRatchetKeyPrivate();
+          onChanged();
+          return this;
+        }
+
+        // optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;
+        private org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey chainKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.getDefaultInstance();
+        private com.google.protobuf.SingleFieldBuilder<
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKeyOrBuilder> chainKeyBuilder_;
+        /**
+         * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+         */
+        public boolean hasChainKey() {
+          return ((bitField0_ & 0x00000004) == 0x00000004);
+        }
+        /**
+         * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+         */
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey getChainKey() {
+          if (chainKeyBuilder_ == null) {
+            return chainKey_;
+          } else {
+            return chainKeyBuilder_.getMessage();
+          }
+        }
+        /**
+         * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+         */
+        public Builder setChainKey(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey value) {
+          if (chainKeyBuilder_ == null) {
+            if (value == null) {
+              throw new NullPointerException();
+            }
+            chainKey_ = value;
+            onChanged();
+          } else {
+            chainKeyBuilder_.setMessage(value);
+          }
+          bitField0_ |= 0x00000004;
+          return this;
+        }
+        /**
+         * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+         */
+        public Builder setChainKey(
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.Builder builderForValue) {
+          if (chainKeyBuilder_ == null) {
+            chainKey_ = builderForValue.build();
+            onChanged();
+          } else {
+            chainKeyBuilder_.setMessage(builderForValue.build());
+          }
+          bitField0_ |= 0x00000004;
+          return this;
+        }
+        /**
+         * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+         */
+        public Builder mergeChainKey(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey value) {
+          if (chainKeyBuilder_ == null) {
+            if (((bitField0_ & 0x00000004) == 0x00000004) &&
+                chainKey_ != org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.getDefaultInstance()) {
+              chainKey_ =
+                org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.newBuilder(chainKey_).mergeFrom(value).buildPartial();
+            } else {
+              chainKey_ = value;
+            }
+            onChanged();
+          } else {
+            chainKeyBuilder_.mergeFrom(value);
+          }
+          bitField0_ |= 0x00000004;
+          return this;
+        }
+        /**
+         * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+         */
+        public Builder clearChainKey() {
+          if (chainKeyBuilder_ == null) {
+            chainKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.getDefaultInstance();
+            onChanged();
+          } else {
+            chainKeyBuilder_.clear();
+          }
+          bitField0_ = (bitField0_ & ~0x00000004);
+          return this;
+        }
+        /**
+         * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+         */
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.Builder getChainKeyBuilder() {
+          bitField0_ |= 0x00000004;
+          onChanged();
+          return getChainKeyFieldBuilder().getBuilder();
+        }
+        /**
+         * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+         */
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKeyOrBuilder getChainKeyOrBuilder() {
+          if (chainKeyBuilder_ != null) {
+            return chainKeyBuilder_.getMessageOrBuilder();
+          } else {
+            return chainKey_;
+          }
+        }
+        /**
+         * <code>optional .textsecure.SessionStructure.Chain.ChainKey chainKey = 3;</code>
+         */
+        private com.google.protobuf.SingleFieldBuilder<
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKeyOrBuilder> 
+            getChainKeyFieldBuilder() {
+          if (chainKeyBuilder_ == null) {
+            chainKeyBuilder_ = new com.google.protobuf.SingleFieldBuilder<
+                org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.ChainKeyOrBuilder>(
+                    chainKey_,
+                    getParentForChildren(),
+                    isClean());
+            chainKey_ = null;
+          }
+          return chainKeyBuilder_;
+        }
+
+        // repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;
+        private java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey> messageKeys_ =
+          java.util.Collections.emptyList();
+        private void ensureMessageKeysIsMutable() {
+          if (!((bitField0_ & 0x00000008) == 0x00000008)) {
+            messageKeys_ = new java.util.ArrayList<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey>(messageKeys_);
+            bitField0_ |= 0x00000008;
+           }
+        }
+
+        private com.google.protobuf.RepeatedFieldBuilder<
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKeyOrBuilder> messageKeysBuilder_;
+
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey> getMessageKeysList() {
+          if (messageKeysBuilder_ == null) {
+            return java.util.Collections.unmodifiableList(messageKeys_);
+          } else {
+            return messageKeysBuilder_.getMessageList();
+          }
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public int getMessageKeysCount() {
+          if (messageKeysBuilder_ == null) {
+            return messageKeys_.size();
+          } else {
+            return messageKeysBuilder_.getCount();
+          }
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey getMessageKeys(int index) {
+          if (messageKeysBuilder_ == null) {
+            return messageKeys_.get(index);
+          } else {
+            return messageKeysBuilder_.getMessage(index);
+          }
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public Builder setMessageKeys(
+            int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey value) {
+          if (messageKeysBuilder_ == null) {
+            if (value == null) {
+              throw new NullPointerException();
+            }
+            ensureMessageKeysIsMutable();
+            messageKeys_.set(index, value);
+            onChanged();
+          } else {
+            messageKeysBuilder_.setMessage(index, value);
+          }
+          return this;
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public Builder setMessageKeys(
+            int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder builderForValue) {
+          if (messageKeysBuilder_ == null) {
+            ensureMessageKeysIsMutable();
+            messageKeys_.set(index, builderForValue.build());
+            onChanged();
+          } else {
+            messageKeysBuilder_.setMessage(index, builderForValue.build());
+          }
+          return this;
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public Builder addMessageKeys(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey value) {
+          if (messageKeysBuilder_ == null) {
+            if (value == null) {
+              throw new NullPointerException();
+            }
+            ensureMessageKeysIsMutable();
+            messageKeys_.add(value);
+            onChanged();
+          } else {
+            messageKeysBuilder_.addMessage(value);
+          }
+          return this;
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public Builder addMessageKeys(
+            int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey value) {
+          if (messageKeysBuilder_ == null) {
+            if (value == null) {
+              throw new NullPointerException();
+            }
+            ensureMessageKeysIsMutable();
+            messageKeys_.add(index, value);
+            onChanged();
+          } else {
+            messageKeysBuilder_.addMessage(index, value);
+          }
+          return this;
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public Builder addMessageKeys(
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder builderForValue) {
+          if (messageKeysBuilder_ == null) {
+            ensureMessageKeysIsMutable();
+            messageKeys_.add(builderForValue.build());
+            onChanged();
+          } else {
+            messageKeysBuilder_.addMessage(builderForValue.build());
+          }
+          return this;
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public Builder addMessageKeys(
+            int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder builderForValue) {
+          if (messageKeysBuilder_ == null) {
+            ensureMessageKeysIsMutable();
+            messageKeys_.add(index, builderForValue.build());
+            onChanged();
+          } else {
+            messageKeysBuilder_.addMessage(index, builderForValue.build());
+          }
+          return this;
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public Builder addAllMessageKeys(
+            java.lang.Iterable<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey> values) {
+          if (messageKeysBuilder_ == null) {
+            ensureMessageKeysIsMutable();
+            super.addAll(values, messageKeys_);
+            onChanged();
+          } else {
+            messageKeysBuilder_.addAllMessages(values);
+          }
+          return this;
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public Builder clearMessageKeys() {
+          if (messageKeysBuilder_ == null) {
+            messageKeys_ = java.util.Collections.emptyList();
+            bitField0_ = (bitField0_ & ~0x00000008);
+            onChanged();
+          } else {
+            messageKeysBuilder_.clear();
+          }
+          return this;
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public Builder removeMessageKeys(int index) {
+          if (messageKeysBuilder_ == null) {
+            ensureMessageKeysIsMutable();
+            messageKeys_.remove(index);
+            onChanged();
+          } else {
+            messageKeysBuilder_.remove(index);
+          }
+          return this;
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder getMessageKeysBuilder(
+            int index) {
+          return getMessageKeysFieldBuilder().getBuilder(index);
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKeyOrBuilder getMessageKeysOrBuilder(
+            int index) {
+          if (messageKeysBuilder_ == null) {
+            return messageKeys_.get(index);  } else {
+            return messageKeysBuilder_.getMessageOrBuilder(index);
+          }
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKeyOrBuilder> 
+             getMessageKeysOrBuilderList() {
+          if (messageKeysBuilder_ != null) {
+            return messageKeysBuilder_.getMessageOrBuilderList();
+          } else {
+            return java.util.Collections.unmodifiableList(messageKeys_);
+          }
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder addMessageKeysBuilder() {
+          return getMessageKeysFieldBuilder().addBuilder(
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.getDefaultInstance());
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder addMessageKeysBuilder(
+            int index) {
+          return getMessageKeysFieldBuilder().addBuilder(
+              index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.getDefaultInstance());
+        }
+        /**
+         * <code>repeated .textsecure.SessionStructure.Chain.MessageKey messageKeys = 4;</code>
+         */
+        public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder> 
+             getMessageKeysBuilderList() {
+          return getMessageKeysFieldBuilder().getBuilderList();
+        }
+        private com.google.protobuf.RepeatedFieldBuilder<
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKeyOrBuilder> 
+            getMessageKeysFieldBuilder() {
+          if (messageKeysBuilder_ == null) {
+            messageKeysBuilder_ = new com.google.protobuf.RepeatedFieldBuilder<
+                org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.MessageKeyOrBuilder>(
+                    messageKeys_,
+                    ((bitField0_ & 0x00000008) == 0x00000008),
+                    getParentForChildren(),
+                    isClean());
+            messageKeys_ = null;
+          }
+          return messageKeysBuilder_;
+        }
+
+        // @@protoc_insertion_point(builder_scope:textsecure.SessionStructure.Chain)
+      }
+
+      static {
+        defaultInstance = new Chain(true);
+        defaultInstance.initFields();
+      }
+
+      // @@protoc_insertion_point(class_scope:textsecure.SessionStructure.Chain)
+    }
+
+    public interface PendingKeyExchangeOrBuilder
+        extends com.google.protobuf.MessageOrBuilder {
+
+      // optional uint32 sequence = 1;
+      /**
+       * <code>optional uint32 sequence = 1;</code>
+       */
+      boolean hasSequence();
+      /**
+       * <code>optional uint32 sequence = 1;</code>
+       */
+      int getSequence();
+
+      // optional bytes localBaseKey = 2;
+      /**
+       * <code>optional bytes localBaseKey = 2;</code>
+       */
+      boolean hasLocalBaseKey();
+      /**
+       * <code>optional bytes localBaseKey = 2;</code>
+       */
+      com.google.protobuf.ByteString getLocalBaseKey();
+
+      // optional bytes localBaseKeyPrivate = 3;
+      /**
+       * <code>optional bytes localBaseKeyPrivate = 3;</code>
+       */
+      boolean hasLocalBaseKeyPrivate();
+      /**
+       * <code>optional bytes localBaseKeyPrivate = 3;</code>
+       */
+      com.google.protobuf.ByteString getLocalBaseKeyPrivate();
+
+      // optional bytes localRatchetKey = 4;
+      /**
+       * <code>optional bytes localRatchetKey = 4;</code>
+       */
+      boolean hasLocalRatchetKey();
+      /**
+       * <code>optional bytes localRatchetKey = 4;</code>
+       */
+      com.google.protobuf.ByteString getLocalRatchetKey();
+
+      // optional bytes localRatchetKeyPrivate = 5;
+      /**
+       * <code>optional bytes localRatchetKeyPrivate = 5;</code>
+       */
+      boolean hasLocalRatchetKeyPrivate();
+      /**
+       * <code>optional bytes localRatchetKeyPrivate = 5;</code>
+       */
+      com.google.protobuf.ByteString getLocalRatchetKeyPrivate();
+
+      // optional bytes localIdentityKey = 7;
+      /**
+       * <code>optional bytes localIdentityKey = 7;</code>
+       */
+      boolean hasLocalIdentityKey();
+      /**
+       * <code>optional bytes localIdentityKey = 7;</code>
+       */
+      com.google.protobuf.ByteString getLocalIdentityKey();
+
+      // optional bytes localIdentityKeyPrivate = 8;
+      /**
+       * <code>optional bytes localIdentityKeyPrivate = 8;</code>
+       */
+      boolean hasLocalIdentityKeyPrivate();
+      /**
+       * <code>optional bytes localIdentityKeyPrivate = 8;</code>
+       */
+      com.google.protobuf.ByteString getLocalIdentityKeyPrivate();
+    }
+    /**
+     * Protobuf type {@code textsecure.SessionStructure.PendingKeyExchange}
+     */
+    public static final class PendingKeyExchange extends
+        com.google.protobuf.GeneratedMessage
+        implements PendingKeyExchangeOrBuilder {
+      // Use PendingKeyExchange.newBuilder() to construct.
+      private PendingKeyExchange(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+        super(builder);
+        this.unknownFields = builder.getUnknownFields();
+      }
+      private PendingKeyExchange(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+      private static final PendingKeyExchange defaultInstance;
+      public static PendingKeyExchange getDefaultInstance() {
+        return defaultInstance;
+      }
+
+      public PendingKeyExchange getDefaultInstanceForType() {
+        return defaultInstance;
+      }
+
+      private final com.google.protobuf.UnknownFieldSet unknownFields;
+      @java.lang.Override
+      public final com.google.protobuf.UnknownFieldSet
+          getUnknownFields() {
+        return this.unknownFields;
+      }
+      private PendingKeyExchange(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        initFields();
+        int mutable_bitField0_ = 0;
+        com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+            com.google.protobuf.UnknownFieldSet.newBuilder();
+        try {
+          boolean done = false;
+          while (!done) {
+            int tag = input.readTag();
+            switch (tag) {
+              case 0:
+                done = true;
+                break;
+              default: {
+                if (!parseUnknownField(input, unknownFields,
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+                bitField0_ |= 0x00000002;
+                localBaseKey_ = input.readBytes();
+                break;
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+              case 26: {
+                bitField0_ |= 0x00000004;
+                localBaseKeyPrivate_ = input.readBytes();
+                break;
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+              case 34: {
+                bitField0_ |= 0x00000008;
+                localRatchetKey_ = input.readBytes();
+                break;
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+              case 42: {
+                bitField0_ |= 0x00000010;
+                localRatchetKeyPrivate_ = input.readBytes();
+                break;
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+              case 58: {
+                bitField0_ |= 0x00000020;
+                localIdentityKey_ = input.readBytes();
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+                localIdentityKeyPrivate_ = input.readBytes();
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+          throw e.setUnfinishedMessage(this);
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+              e.getMessage()).setUnfinishedMessage(this);
+        } finally {
+          this.unknownFields = unknownFields.build();
+          makeExtensionsImmutable();
+        }
+      }
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_PendingKeyExchange_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_PendingKeyExchange_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.Builder.class);
+      }
+
+      public static com.google.protobuf.Parser<PendingKeyExchange> PARSER =
+          new com.google.protobuf.AbstractParser<PendingKeyExchange>() {
+        public PendingKeyExchange parsePartialFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return new PendingKeyExchange(input, extensionRegistry);
+        }
+      };
+
+      @java.lang.Override
+      public com.google.protobuf.Parser<PendingKeyExchange> getParserForType() {
+        return PARSER;
+      }
+
+      private int bitField0_;
+      // optional uint32 sequence = 1;
+      public static final int SEQUENCE_FIELD_NUMBER = 1;
+      private int sequence_;
+      /**
+       * <code>optional uint32 sequence = 1;</code>
+       */
+      public boolean hasSequence() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional uint32 sequence = 1;</code>
+       */
+      public int getSequence() {
+        return sequence_;
+      }
+
+      // optional bytes localBaseKey = 2;
+      public static final int LOCALBASEKEY_FIELD_NUMBER = 2;
+      private com.google.protobuf.ByteString localBaseKey_;
+      /**
+       * <code>optional bytes localBaseKey = 2;</code>
+       */
+      public boolean hasLocalBaseKey() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional bytes localBaseKey = 2;</code>
+       */
+      public com.google.protobuf.ByteString getLocalBaseKey() {
+        return localBaseKey_;
+      }
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+      // optional bytes localBaseKeyPrivate = 3;
+      public static final int LOCALBASEKEYPRIVATE_FIELD_NUMBER = 3;
+      private com.google.protobuf.ByteString localBaseKeyPrivate_;
+      /**
+       * <code>optional bytes localBaseKeyPrivate = 3;</code>
+       */
+      public boolean hasLocalBaseKeyPrivate() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
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+      /**
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+      public com.google.protobuf.ByteString getLocalBaseKeyPrivate() {
+        return localBaseKeyPrivate_;
+      }
+
+      // optional bytes localRatchetKey = 4;
+      public static final int LOCALRATCHETKEY_FIELD_NUMBER = 4;
+      private com.google.protobuf.ByteString localRatchetKey_;
+      /**
+       * <code>optional bytes localRatchetKey = 4;</code>
+       */
+      public boolean hasLocalRatchetKey() {
+        return ((bitField0_ & 0x00000008) == 0x00000008);
+      }
+      /**
+       * <code>optional bytes localRatchetKey = 4;</code>
+       */
+      public com.google.protobuf.ByteString getLocalRatchetKey() {
+        return localRatchetKey_;
+      }
+
+      // optional bytes localRatchetKeyPrivate = 5;
+      public static final int LOCALRATCHETKEYPRIVATE_FIELD_NUMBER = 5;
+      private com.google.protobuf.ByteString localRatchetKeyPrivate_;
+      /**
+       * <code>optional bytes localRatchetKeyPrivate = 5;</code>
+       */
+      public boolean hasLocalRatchetKeyPrivate() {
+        return ((bitField0_ & 0x00000010) == 0x00000010);
+      }
+      /**
+       * <code>optional bytes localRatchetKeyPrivate = 5;</code>
+       */
+      public com.google.protobuf.ByteString getLocalRatchetKeyPrivate() {
+        return localRatchetKeyPrivate_;
+      }
+
+      // optional bytes localIdentityKey = 7;
+      public static final int LOCALIDENTITYKEY_FIELD_NUMBER = 7;
+      private com.google.protobuf.ByteString localIdentityKey_;
+      /**
+       * <code>optional bytes localIdentityKey = 7;</code>
+       */
+      public boolean hasLocalIdentityKey() {
+        return ((bitField0_ & 0x00000020) == 0x00000020);
+      }
+      /**
+       * <code>optional bytes localIdentityKey = 7;</code>
+       */
+      public com.google.protobuf.ByteString getLocalIdentityKey() {
+        return localIdentityKey_;
+      }
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+      // optional bytes localIdentityKeyPrivate = 8;
+      public static final int LOCALIDENTITYKEYPRIVATE_FIELD_NUMBER = 8;
+      private com.google.protobuf.ByteString localIdentityKeyPrivate_;
+      /**
+       * <code>optional bytes localIdentityKeyPrivate = 8;</code>
+       */
+      public boolean hasLocalIdentityKeyPrivate() {
+        return ((bitField0_ & 0x00000040) == 0x00000040);
+      }
+      /**
+       * <code>optional bytes localIdentityKeyPrivate = 8;</code>
+       */
+      public com.google.protobuf.ByteString getLocalIdentityKeyPrivate() {
+        return localIdentityKeyPrivate_;
+      }
+
+      private void initFields() {
+        sequence_ = 0;
+        localBaseKey_ = com.google.protobuf.ByteString.EMPTY;
+        localBaseKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+        localRatchetKey_ = com.google.protobuf.ByteString.EMPTY;
+        localRatchetKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+        localIdentityKey_ = com.google.protobuf.ByteString.EMPTY;
+        localIdentityKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+      }
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+        byte isInitialized = memoizedIsInitialized;
+        if (isInitialized != -1) return isInitialized == 1;
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+        memoizedIsInitialized = 1;
+        return true;
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+      public void writeTo(com.google.protobuf.CodedOutputStream output)
+                          throws java.io.IOException {
+        getSerializedSize();
+        if (((bitField0_ & 0x00000001) == 0x00000001)) {
+          output.writeUInt32(1, sequence_);
+        }
+        if (((bitField0_ & 0x00000002) == 0x00000002)) {
+          output.writeBytes(2, localBaseKey_);
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+        if (((bitField0_ & 0x00000004) == 0x00000004)) {
+          output.writeBytes(3, localBaseKeyPrivate_);
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+        if (((bitField0_ & 0x00000008) == 0x00000008)) {
+          output.writeBytes(4, localRatchetKey_);
+        }
+        if (((bitField0_ & 0x00000010) == 0x00000010)) {
+          output.writeBytes(5, localRatchetKeyPrivate_);
+        }
+        if (((bitField0_ & 0x00000020) == 0x00000020)) {
+          output.writeBytes(7, localIdentityKey_);
+        }
+        if (((bitField0_ & 0x00000040) == 0x00000040)) {
+          output.writeBytes(8, localIdentityKeyPrivate_);
+        }
+        getUnknownFields().writeTo(output);
+      }
+
+      private int memoizedSerializedSize = -1;
+      public int getSerializedSize() {
+        int size = memoizedSerializedSize;
+        if (size != -1) return size;
+
+        size = 0;
+        if (((bitField0_ & 0x00000001) == 0x00000001)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeUInt32Size(1, sequence_);
+        }
+        if (((bitField0_ & 0x00000002) == 0x00000002)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeBytesSize(2, localBaseKey_);
+        }
+        if (((bitField0_ & 0x00000004) == 0x00000004)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeBytesSize(3, localBaseKeyPrivate_);
+        }
+        if (((bitField0_ & 0x00000008) == 0x00000008)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeBytesSize(4, localRatchetKey_);
+        }
+        if (((bitField0_ & 0x00000010) == 0x00000010)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeBytesSize(5, localRatchetKeyPrivate_);
+        }
+        if (((bitField0_ & 0x00000020) == 0x00000020)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeBytesSize(7, localIdentityKey_);
+        }
+        if (((bitField0_ & 0x00000040) == 0x00000040)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeBytesSize(8, localIdentityKeyPrivate_);
+        }
+        size += getUnknownFields().getSerializedSize();
+        memoizedSerializedSize = size;
+        return size;
+      }
+
+      private static final long serialVersionUID = 0L;
+      @java.lang.Override
+      protected java.lang.Object writeReplace()
+          throws java.io.ObjectStreamException {
+        return super.writeReplace();
+      }
+
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange parseFrom(
+          com.google.protobuf.ByteString data)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange parseFrom(
+          com.google.protobuf.ByteString data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange parseFrom(byte[] data)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange parseFrom(
+          byte[] data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange parseFrom(java.io.InputStream input)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange parseFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange parseDelimitedFrom(java.io.InputStream input)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange parseDelimitedFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange parseFrom(
+          com.google.protobuf.CodedInputStream input)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange parseFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
+      }
+
+      public static Builder newBuilder() { return Builder.create(); }
+      public Builder newBuilderForType() { return newBuilder(); }
+      public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange prototype) {
+        return newBuilder().mergeFrom(prototype);
+      }
+      public Builder toBuilder() { return newBuilder(this); }
+
+      @java.lang.Override
+      protected Builder newBuilderForType(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        Builder builder = new Builder(parent);
+        return builder;
+      }
+      /**
+       * Protobuf type {@code textsecure.SessionStructure.PendingKeyExchange}
+       */
+      public static final class Builder extends
+          com.google.protobuf.GeneratedMessage.Builder<Builder>
+         implements org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchangeOrBuilder {
+        public static final com.google.protobuf.Descriptors.Descriptor
+            getDescriptor() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_PendingKeyExchange_descriptor;
+        }
+
+        protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+            internalGetFieldAccessorTable() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_PendingKeyExchange_fieldAccessorTable
+              .ensureFieldAccessorsInitialized(
+                  org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.Builder.class);
+        }
+
+        // Construct using org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.newBuilder()
+        private Builder() {
+          maybeForceBuilderInitialization();
+        }
+
+        private Builder(
+            com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+          super(parent);
+          maybeForceBuilderInitialization();
+        }
+        private void maybeForceBuilderInitialization() {
+          if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+          }
+        }
+        private static Builder create() {
+          return new Builder();
+        }
+
+        public Builder clear() {
+          super.clear();
+          sequence_ = 0;
+          bitField0_ = (bitField0_ & ~0x00000001);
+          localBaseKey_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000002);
+          localBaseKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000004);
+          localRatchetKey_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000008);
+          localRatchetKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000010);
+          localIdentityKey_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000020);
+          localIdentityKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000040);
+          return this;
+        }
+
+        public Builder clone() {
+          return create().mergeFrom(buildPartial());
+        }
+
+        public com.google.protobuf.Descriptors.Descriptor
+            getDescriptorForType() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_PendingKeyExchange_descriptor;
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange getDefaultInstanceForType() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.getDefaultInstance();
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange build() {
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange result = buildPartial();
+          if (!result.isInitialized()) {
+            throw newUninitializedMessageException(result);
+          }
+          return result;
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange buildPartial() {
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange result = new org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange(this);
+          int from_bitField0_ = bitField0_;
+          int to_bitField0_ = 0;
+          if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+            to_bitField0_ |= 0x00000001;
+          }
+          result.sequence_ = sequence_;
+          if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+            to_bitField0_ |= 0x00000002;
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+          result.localBaseKey_ = localBaseKey_;
+          if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+            to_bitField0_ |= 0x00000004;
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+          result.localBaseKeyPrivate_ = localBaseKeyPrivate_;
+          if (((from_bitField0_ & 0x00000008) == 0x00000008)) {
+            to_bitField0_ |= 0x00000008;
+          }
+          result.localRatchetKey_ = localRatchetKey_;
+          if (((from_bitField0_ & 0x00000010) == 0x00000010)) {
+            to_bitField0_ |= 0x00000010;
+          }
+          result.localRatchetKeyPrivate_ = localRatchetKeyPrivate_;
+          if (((from_bitField0_ & 0x00000020) == 0x00000020)) {
+            to_bitField0_ |= 0x00000020;
+          }
+          result.localIdentityKey_ = localIdentityKey_;
+          if (((from_bitField0_ & 0x00000040) == 0x00000040)) {
+            to_bitField0_ |= 0x00000040;
+          }
+          result.localIdentityKeyPrivate_ = localIdentityKeyPrivate_;
+          result.bitField0_ = to_bitField0_;
+          onBuilt();
+          return result;
+        }
+
+        public Builder mergeFrom(com.google.protobuf.Message other) {
+          if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange) {
+            return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange)other);
+          } else {
+            super.mergeFrom(other);
+            return this;
+          }
+        }
+
+        public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange other) {
+          if (other == org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.getDefaultInstance()) return this;
+          if (other.hasSequence()) {
+            setSequence(other.getSequence());
+          }
+          if (other.hasLocalBaseKey()) {
+            setLocalBaseKey(other.getLocalBaseKey());
+          }
+          if (other.hasLocalBaseKeyPrivate()) {
+            setLocalBaseKeyPrivate(other.getLocalBaseKeyPrivate());
+          }
+          if (other.hasLocalRatchetKey()) {
+            setLocalRatchetKey(other.getLocalRatchetKey());
+          }
+          if (other.hasLocalRatchetKeyPrivate()) {
+            setLocalRatchetKeyPrivate(other.getLocalRatchetKeyPrivate());
+          }
+          if (other.hasLocalIdentityKey()) {
+            setLocalIdentityKey(other.getLocalIdentityKey());
+          }
+          if (other.hasLocalIdentityKeyPrivate()) {
+            setLocalIdentityKeyPrivate(other.getLocalIdentityKeyPrivate());
+          }
+          this.mergeUnknownFields(other.getUnknownFields());
+          return this;
+        }
+
+        public final boolean isInitialized() {
+          return true;
+        }
+
+        public Builder mergeFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange parsedMessage = null;
+          try {
+            parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange) e.getUnfinishedMessage();
+            throw e;
+          } finally {
+            if (parsedMessage != null) {
+              mergeFrom(parsedMessage);
+            }
+          }
+          return this;
+        }
+        private int bitField0_;
+
+        // optional uint32 sequence = 1;
+        private int sequence_ ;
+        /**
+         * <code>optional uint32 sequence = 1;</code>
+         */
+        public boolean hasSequence() {
+          return ((bitField0_ & 0x00000001) == 0x00000001);
+        }
+        /**
+         * <code>optional uint32 sequence = 1;</code>
+         */
+        public int getSequence() {
+          return sequence_;
+        }
+        /**
+         * <code>optional uint32 sequence = 1;</code>
+         */
+        public Builder setSequence(int value) {
+          bitField0_ |= 0x00000001;
+          sequence_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional uint32 sequence = 1;</code>
+         */
+        public Builder clearSequence() {
+          bitField0_ = (bitField0_ & ~0x00000001);
+          sequence_ = 0;
+          onChanged();
+          return this;
+        }
+
+        // optional bytes localBaseKey = 2;
+        private com.google.protobuf.ByteString localBaseKey_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes localBaseKey = 2;</code>
+         */
+        public boolean hasLocalBaseKey() {
+          return ((bitField0_ & 0x00000002) == 0x00000002);
+        }
+        /**
+         * <code>optional bytes localBaseKey = 2;</code>
+         */
+        public com.google.protobuf.ByteString getLocalBaseKey() {
+          return localBaseKey_;
+        }
+        /**
+         * <code>optional bytes localBaseKey = 2;</code>
+         */
+        public Builder setLocalBaseKey(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+          localBaseKey_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes localBaseKey = 2;</code>
+         */
+        public Builder clearLocalBaseKey() {
+          bitField0_ = (bitField0_ & ~0x00000002);
+          localBaseKey_ = getDefaultInstance().getLocalBaseKey();
+          onChanged();
+          return this;
+        }
+
+        // optional bytes localBaseKeyPrivate = 3;
+        private com.google.protobuf.ByteString localBaseKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes localBaseKeyPrivate = 3;</code>
+         */
+        public boolean hasLocalBaseKeyPrivate() {
+          return ((bitField0_ & 0x00000004) == 0x00000004);
+        }
+        /**
+         * <code>optional bytes localBaseKeyPrivate = 3;</code>
+         */
+        public com.google.protobuf.ByteString getLocalBaseKeyPrivate() {
+          return localBaseKeyPrivate_;
+        }
+        /**
+         * <code>optional bytes localBaseKeyPrivate = 3;</code>
+         */
+        public Builder setLocalBaseKeyPrivate(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000004;
+          localBaseKeyPrivate_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes localBaseKeyPrivate = 3;</code>
+         */
+        public Builder clearLocalBaseKeyPrivate() {
+          bitField0_ = (bitField0_ & ~0x00000004);
+          localBaseKeyPrivate_ = getDefaultInstance().getLocalBaseKeyPrivate();
+          onChanged();
+          return this;
+        }
+
+        // optional bytes localRatchetKey = 4;
+        private com.google.protobuf.ByteString localRatchetKey_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes localRatchetKey = 4;</code>
+         */
+        public boolean hasLocalRatchetKey() {
+          return ((bitField0_ & 0x00000008) == 0x00000008);
+        }
+        /**
+         * <code>optional bytes localRatchetKey = 4;</code>
+         */
+        public com.google.protobuf.ByteString getLocalRatchetKey() {
+          return localRatchetKey_;
+        }
+        /**
+         * <code>optional bytes localRatchetKey = 4;</code>
+         */
+        public Builder setLocalRatchetKey(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000008;
+          localRatchetKey_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes localRatchetKey = 4;</code>
+         */
+        public Builder clearLocalRatchetKey() {
+          bitField0_ = (bitField0_ & ~0x00000008);
+          localRatchetKey_ = getDefaultInstance().getLocalRatchetKey();
+          onChanged();
+          return this;
+        }
+
+        // optional bytes localRatchetKeyPrivate = 5;
+        private com.google.protobuf.ByteString localRatchetKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes localRatchetKeyPrivate = 5;</code>
+         */
+        public boolean hasLocalRatchetKeyPrivate() {
+          return ((bitField0_ & 0x00000010) == 0x00000010);
+        }
+        /**
+         * <code>optional bytes localRatchetKeyPrivate = 5;</code>
+         */
+        public com.google.protobuf.ByteString getLocalRatchetKeyPrivate() {
+          return localRatchetKeyPrivate_;
+        }
+        /**
+         * <code>optional bytes localRatchetKeyPrivate = 5;</code>
+         */
+        public Builder setLocalRatchetKeyPrivate(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000010;
+          localRatchetKeyPrivate_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes localRatchetKeyPrivate = 5;</code>
+         */
+        public Builder clearLocalRatchetKeyPrivate() {
+          bitField0_ = (bitField0_ & ~0x00000010);
+          localRatchetKeyPrivate_ = getDefaultInstance().getLocalRatchetKeyPrivate();
+          onChanged();
+          return this;
+        }
+
+        // optional bytes localIdentityKey = 7;
+        private com.google.protobuf.ByteString localIdentityKey_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes localIdentityKey = 7;</code>
+         */
+        public boolean hasLocalIdentityKey() {
+          return ((bitField0_ & 0x00000020) == 0x00000020);
+        }
+        /**
+         * <code>optional bytes localIdentityKey = 7;</code>
+         */
+        public com.google.protobuf.ByteString getLocalIdentityKey() {
+          return localIdentityKey_;
+        }
+        /**
+         * <code>optional bytes localIdentityKey = 7;</code>
+         */
+        public Builder setLocalIdentityKey(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000020;
+          localIdentityKey_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes localIdentityKey = 7;</code>
+         */
+        public Builder clearLocalIdentityKey() {
+          bitField0_ = (bitField0_ & ~0x00000020);
+          localIdentityKey_ = getDefaultInstance().getLocalIdentityKey();
+          onChanged();
+          return this;
+        }
+
+        // optional bytes localIdentityKeyPrivate = 8;
+        private com.google.protobuf.ByteString localIdentityKeyPrivate_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes localIdentityKeyPrivate = 8;</code>
+         */
+        public boolean hasLocalIdentityKeyPrivate() {
+          return ((bitField0_ & 0x00000040) == 0x00000040);
+        }
+        /**
+         * <code>optional bytes localIdentityKeyPrivate = 8;</code>
+         */
+        public com.google.protobuf.ByteString getLocalIdentityKeyPrivate() {
+          return localIdentityKeyPrivate_;
+        }
+        /**
+         * <code>optional bytes localIdentityKeyPrivate = 8;</code>
+         */
+        public Builder setLocalIdentityKeyPrivate(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000040;
+          localIdentityKeyPrivate_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes localIdentityKeyPrivate = 8;</code>
+         */
+        public Builder clearLocalIdentityKeyPrivate() {
+          bitField0_ = (bitField0_ & ~0x00000040);
+          localIdentityKeyPrivate_ = getDefaultInstance().getLocalIdentityKeyPrivate();
+          onChanged();
+          return this;
+        }
+
+        // @@protoc_insertion_point(builder_scope:textsecure.SessionStructure.PendingKeyExchange)
+      }
+
+      static {
+        defaultInstance = new PendingKeyExchange(true);
+        defaultInstance.initFields();
+      }
+
+      // @@protoc_insertion_point(class_scope:textsecure.SessionStructure.PendingKeyExchange)
+    }
+
+    public interface PendingPreKeyOrBuilder
+        extends com.google.protobuf.MessageOrBuilder {
+
+      // optional uint32 preKeyId = 1;
+      /**
+       * <code>optional uint32 preKeyId = 1;</code>
+       */
+      boolean hasPreKeyId();
+      /**
+       * <code>optional uint32 preKeyId = 1;</code>
+       */
+      int getPreKeyId();
+
+      // optional int32 signedPreKeyId = 3;
+      /**
+       * <code>optional int32 signedPreKeyId = 3;</code>
+       */
+      boolean hasSignedPreKeyId();
+      /**
+       * <code>optional int32 signedPreKeyId = 3;</code>
+       */
+      int getSignedPreKeyId();
+
+      // optional bytes baseKey = 2;
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      boolean hasBaseKey();
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      com.google.protobuf.ByteString getBaseKey();
+    }
+    /**
+     * Protobuf type {@code textsecure.SessionStructure.PendingPreKey}
+     */
+    public static final class PendingPreKey extends
+        com.google.protobuf.GeneratedMessage
+        implements PendingPreKeyOrBuilder {
+      // Use PendingPreKey.newBuilder() to construct.
+      private PendingPreKey(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+        super(builder);
+        this.unknownFields = builder.getUnknownFields();
+      }
+      private PendingPreKey(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+      private static final PendingPreKey defaultInstance;
+      public static PendingPreKey getDefaultInstance() {
+        return defaultInstance;
+      }
+
+      public PendingPreKey getDefaultInstanceForType() {
+        return defaultInstance;
+      }
+
+      private final com.google.protobuf.UnknownFieldSet unknownFields;
+      @java.lang.Override
+      public final com.google.protobuf.UnknownFieldSet
+          getUnknownFields() {
+        return this.unknownFields;
+      }
+      private PendingPreKey(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        initFields();
+        int mutable_bitField0_ = 0;
+        com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+            com.google.protobuf.UnknownFieldSet.newBuilder();
+        try {
+          boolean done = false;
+          while (!done) {
+            int tag = input.readTag();
+            switch (tag) {
+              case 0:
+                done = true;
+                break;
+              default: {
+                if (!parseUnknownField(input, unknownFields,
+                                       extensionRegistry, tag)) {
+                  done = true;
+                }
+                break;
+              }
+              case 8: {
+                bitField0_ |= 0x00000001;
+                preKeyId_ = input.readUInt32();
+                break;
+              }
+              case 18: {
+                bitField0_ |= 0x00000004;
+                baseKey_ = input.readBytes();
+                break;
+              }
+              case 24: {
+                bitField0_ |= 0x00000002;
+                signedPreKeyId_ = input.readInt32();
+                break;
+              }
+            }
+          }
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          throw e.setUnfinishedMessage(this);
+        } catch (java.io.IOException e) {
+          throw new com.google.protobuf.InvalidProtocolBufferException(
+              e.getMessage()).setUnfinishedMessage(this);
+        } finally {
+          this.unknownFields = unknownFields.build();
+          makeExtensionsImmutable();
+        }
+      }
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_PendingPreKey_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_PendingPreKey_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.Builder.class);
+      }
+
+      public static com.google.protobuf.Parser<PendingPreKey> PARSER =
+          new com.google.protobuf.AbstractParser<PendingPreKey>() {
+        public PendingPreKey parsePartialFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return new PendingPreKey(input, extensionRegistry);
+        }
+      };
+
+      @java.lang.Override
+      public com.google.protobuf.Parser<PendingPreKey> getParserForType() {
+        return PARSER;
+      }
+
+      private int bitField0_;
+      // optional uint32 preKeyId = 1;
+      public static final int PREKEYID_FIELD_NUMBER = 1;
+      private int preKeyId_;
+      /**
+       * <code>optional uint32 preKeyId = 1;</code>
+       */
+      public boolean hasPreKeyId() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional uint32 preKeyId = 1;</code>
+       */
+      public int getPreKeyId() {
+        return preKeyId_;
+      }
+
+      // optional int32 signedPreKeyId = 3;
+      public static final int SIGNEDPREKEYID_FIELD_NUMBER = 3;
+      private int signedPreKeyId_;
+      /**
+       * <code>optional int32 signedPreKeyId = 3;</code>
+       */
+      public boolean hasSignedPreKeyId() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional int32 signedPreKeyId = 3;</code>
+       */
+      public int getSignedPreKeyId() {
+        return signedPreKeyId_;
+      }
+
+      // optional bytes baseKey = 2;
+      public static final int BASEKEY_FIELD_NUMBER = 2;
+      private com.google.protobuf.ByteString baseKey_;
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      public boolean hasBaseKey() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional bytes baseKey = 2;</code>
+       */
+      public com.google.protobuf.ByteString getBaseKey() {
+        return baseKey_;
+      }
+
+      private void initFields() {
+        preKeyId_ = 0;
+        signedPreKeyId_ = 0;
+        baseKey_ = com.google.protobuf.ByteString.EMPTY;
+      }
+      private byte memoizedIsInitialized = -1;
+      public final boolean isInitialized() {
+        byte isInitialized = memoizedIsInitialized;
+        if (isInitialized != -1) return isInitialized == 1;
+
+        memoizedIsInitialized = 1;
+        return true;
+      }
+
+      public void writeTo(com.google.protobuf.CodedOutputStream output)
+                          throws java.io.IOException {
+        getSerializedSize();
+        if (((bitField0_ & 0x00000001) == 0x00000001)) {
+          output.writeUInt32(1, preKeyId_);
+        }
+        if (((bitField0_ & 0x00000004) == 0x00000004)) {
+          output.writeBytes(2, baseKey_);
+        }
+        if (((bitField0_ & 0x00000002) == 0x00000002)) {
+          output.writeInt32(3, signedPreKeyId_);
+        }
+        getUnknownFields().writeTo(output);
+      }
+
+      private int memoizedSerializedSize = -1;
+      public int getSerializedSize() {
+        int size = memoizedSerializedSize;
+        if (size != -1) return size;
+
+        size = 0;
+        if (((bitField0_ & 0x00000001) == 0x00000001)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeUInt32Size(1, preKeyId_);
+        }
+        if (((bitField0_ & 0x00000004) == 0x00000004)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeBytesSize(2, baseKey_);
+        }
+        if (((bitField0_ & 0x00000002) == 0x00000002)) {
+          size += com.google.protobuf.CodedOutputStream
+            .computeInt32Size(3, signedPreKeyId_);
+        }
+        size += getUnknownFields().getSerializedSize();
+        memoizedSerializedSize = size;
+        return size;
+      }
+
+      private static final long serialVersionUID = 0L;
+      @java.lang.Override
+      protected java.lang.Object writeReplace()
+          throws java.io.ObjectStreamException {
+        return super.writeReplace();
+      }
+
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey parseFrom(
+          com.google.protobuf.ByteString data)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey parseFrom(
+          com.google.protobuf.ByteString data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey parseFrom(byte[] data)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey parseFrom(
+          byte[] data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey parseFrom(java.io.InputStream input)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey parseFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey parseDelimitedFrom(java.io.InputStream input)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey parseDelimitedFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey parseFrom(
+          com.google.protobuf.CodedInputStream input)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey parseFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
+      }
+
+      public static Builder newBuilder() { return Builder.create(); }
+      public Builder newBuilderForType() { return newBuilder(); }
+      public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey prototype) {
+        return newBuilder().mergeFrom(prototype);
+      }
+      public Builder toBuilder() { return newBuilder(this); }
+
+      @java.lang.Override
+      protected Builder newBuilderForType(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        Builder builder = new Builder(parent);
+        return builder;
+      }
+      /**
+       * Protobuf type {@code textsecure.SessionStructure.PendingPreKey}
+       */
+      public static final class Builder extends
+          com.google.protobuf.GeneratedMessage.Builder<Builder>
+         implements org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKeyOrBuilder {
+        public static final com.google.protobuf.Descriptors.Descriptor
+            getDescriptor() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_PendingPreKey_descriptor;
+        }
+
+        protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+            internalGetFieldAccessorTable() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_PendingPreKey_fieldAccessorTable
+              .ensureFieldAccessorsInitialized(
+                  org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.Builder.class);
+        }
+
+        // Construct using org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.newBuilder()
+        private Builder() {
+          maybeForceBuilderInitialization();
+        }
+
+        private Builder(
+            com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+          super(parent);
+          maybeForceBuilderInitialization();
+        }
+        private void maybeForceBuilderInitialization() {
+          if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+          }
+        }
+        private static Builder create() {
+          return new Builder();
+        }
+
+        public Builder clear() {
+          super.clear();
+          preKeyId_ = 0;
+          bitField0_ = (bitField0_ & ~0x00000001);
+          signedPreKeyId_ = 0;
+          bitField0_ = (bitField0_ & ~0x00000002);
+          baseKey_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000004);
+          return this;
+        }
+
+        public Builder clone() {
+          return create().mergeFrom(buildPartial());
+        }
+
+        public com.google.protobuf.Descriptors.Descriptor
+            getDescriptorForType() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_PendingPreKey_descriptor;
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey getDefaultInstanceForType() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.getDefaultInstance();
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey build() {
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey result = buildPartial();
+          if (!result.isInitialized()) {
+            throw newUninitializedMessageException(result);
+          }
+          return result;
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey buildPartial() {
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey result = new org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey(this);
+          int from_bitField0_ = bitField0_;
+          int to_bitField0_ = 0;
+          if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+            to_bitField0_ |= 0x00000001;
+          }
+          result.preKeyId_ = preKeyId_;
+          if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+            to_bitField0_ |= 0x00000002;
+          }
+          result.signedPreKeyId_ = signedPreKeyId_;
+          if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+            to_bitField0_ |= 0x00000004;
+          }
+          result.baseKey_ = baseKey_;
+          result.bitField0_ = to_bitField0_;
+          onBuilt();
+          return result;
+        }
+
+        public Builder mergeFrom(com.google.protobuf.Message other) {
+          if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey) {
+            return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey)other);
+          } else {
+            super.mergeFrom(other);
+            return this;
+          }
+        }
+
+        public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey other) {
+          if (other == org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.getDefaultInstance()) return this;
+          if (other.hasPreKeyId()) {
+            setPreKeyId(other.getPreKeyId());
+          }
+          if (other.hasSignedPreKeyId()) {
+            setSignedPreKeyId(other.getSignedPreKeyId());
+          }
+          if (other.hasBaseKey()) {
+            setBaseKey(other.getBaseKey());
+          }
+          this.mergeUnknownFields(other.getUnknownFields());
+          return this;
+        }
+
+        public final boolean isInitialized() {
+          return true;
+        }
+
+        public Builder mergeFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey parsedMessage = null;
+          try {
+            parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey) e.getUnfinishedMessage();
+            throw e;
+          } finally {
+            if (parsedMessage != null) {
+              mergeFrom(parsedMessage);
+            }
+          }
+          return this;
+        }
+        private int bitField0_;
+
+        // optional uint32 preKeyId = 1;
+        private int preKeyId_ ;
+        /**
+         * <code>optional uint32 preKeyId = 1;</code>
+         */
+        public boolean hasPreKeyId() {
+          return ((bitField0_ & 0x00000001) == 0x00000001);
+        }
+        /**
+         * <code>optional uint32 preKeyId = 1;</code>
+         */
+        public int getPreKeyId() {
+          return preKeyId_;
+        }
+        /**
+         * <code>optional uint32 preKeyId = 1;</code>
+         */
+        public Builder setPreKeyId(int value) {
+          bitField0_ |= 0x00000001;
+          preKeyId_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional uint32 preKeyId = 1;</code>
+         */
+        public Builder clearPreKeyId() {
+          bitField0_ = (bitField0_ & ~0x00000001);
+          preKeyId_ = 0;
+          onChanged();
+          return this;
+        }
+
+        // optional int32 signedPreKeyId = 3;
+        private int signedPreKeyId_ ;
+        /**
+         * <code>optional int32 signedPreKeyId = 3;</code>
+         */
+        public boolean hasSignedPreKeyId() {
+          return ((bitField0_ & 0x00000002) == 0x00000002);
+        }
+        /**
+         * <code>optional int32 signedPreKeyId = 3;</code>
+         */
+        public int getSignedPreKeyId() {
+          return signedPreKeyId_;
+        }
+        /**
+         * <code>optional int32 signedPreKeyId = 3;</code>
+         */
+        public Builder setSignedPreKeyId(int value) {
+          bitField0_ |= 0x00000002;
+          signedPreKeyId_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional int32 signedPreKeyId = 3;</code>
+         */
+        public Builder clearSignedPreKeyId() {
+          bitField0_ = (bitField0_ & ~0x00000002);
+          signedPreKeyId_ = 0;
+          onChanged();
+          return this;
+        }
+
+        // optional bytes baseKey = 2;
+        private com.google.protobuf.ByteString baseKey_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes baseKey = 2;</code>
+         */
+        public boolean hasBaseKey() {
+          return ((bitField0_ & 0x00000004) == 0x00000004);
+        }
+        /**
+         * <code>optional bytes baseKey = 2;</code>
+         */
+        public com.google.protobuf.ByteString getBaseKey() {
+          return baseKey_;
+        }
+        /**
+         * <code>optional bytes baseKey = 2;</code>
+         */
+        public Builder setBaseKey(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000004;
+          baseKey_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes baseKey = 2;</code>
+         */
+        public Builder clearBaseKey() {
+          bitField0_ = (bitField0_ & ~0x00000004);
+          baseKey_ = getDefaultInstance().getBaseKey();
+          onChanged();
+          return this;
+        }
+
+        // @@protoc_insertion_point(builder_scope:textsecure.SessionStructure.PendingPreKey)
+      }
+
+      static {
+        defaultInstance = new PendingPreKey(true);
+        defaultInstance.initFields();
+      }
+
+      // @@protoc_insertion_point(class_scope:textsecure.SessionStructure.PendingPreKey)
+    }
+
+    private int bitField0_;
+    // optional uint32 sessionVersion = 1;
+    public static final int SESSIONVERSION_FIELD_NUMBER = 1;
+    private int sessionVersion_;
+    /**
+     * <code>optional uint32 sessionVersion = 1;</code>
+     */
+    public boolean hasSessionVersion() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional uint32 sessionVersion = 1;</code>
+     */
+    public int getSessionVersion() {
+      return sessionVersion_;
+    }
+
+    // optional bytes localIdentityPublic = 2;
+    public static final int LOCALIDENTITYPUBLIC_FIELD_NUMBER = 2;
+    private com.google.protobuf.ByteString localIdentityPublic_;
+    /**
+     * <code>optional bytes localIdentityPublic = 2;</code>
+     */
+    public boolean hasLocalIdentityPublic() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>optional bytes localIdentityPublic = 2;</code>
+     */
+    public com.google.protobuf.ByteString getLocalIdentityPublic() {
+      return localIdentityPublic_;
+    }
+
+    // optional bytes remoteIdentityPublic = 3;
+    public static final int REMOTEIDENTITYPUBLIC_FIELD_NUMBER = 3;
+    private com.google.protobuf.ByteString remoteIdentityPublic_;
+    /**
+     * <code>optional bytes remoteIdentityPublic = 3;</code>
+     */
+    public boolean hasRemoteIdentityPublic() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>optional bytes remoteIdentityPublic = 3;</code>
+     */
+    public com.google.protobuf.ByteString getRemoteIdentityPublic() {
+      return remoteIdentityPublic_;
+    }
+
+    // optional bytes rootKey = 4;
+    public static final int ROOTKEY_FIELD_NUMBER = 4;
+    private com.google.protobuf.ByteString rootKey_;
+    /**
+     * <code>optional bytes rootKey = 4;</code>
+     */
+    public boolean hasRootKey() {
+      return ((bitField0_ & 0x00000008) == 0x00000008);
+    }
+    /**
+     * <code>optional bytes rootKey = 4;</code>
+     */
+    public com.google.protobuf.ByteString getRootKey() {
+      return rootKey_;
+    }
+
+    // optional uint32 previousCounter = 5;
+    public static final int PREVIOUSCOUNTER_FIELD_NUMBER = 5;
+    private int previousCounter_;
+    /**
+     * <code>optional uint32 previousCounter = 5;</code>
+     */
+    public boolean hasPreviousCounter() {
+      return ((bitField0_ & 0x00000010) == 0x00000010);
+    }
+    /**
+     * <code>optional uint32 previousCounter = 5;</code>
+     */
+    public int getPreviousCounter() {
+      return previousCounter_;
+    }
+
+    // optional .textsecure.SessionStructure.Chain senderChain = 6;
+    public static final int SENDERCHAIN_FIELD_NUMBER = 6;
+    private org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain senderChain_;
+    /**
+     * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+     */
+    public boolean hasSenderChain() {
+      return ((bitField0_ & 0x00000020) == 0x00000020);
+    }
+    /**
+     * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain getSenderChain() {
+      return senderChain_;
+    }
+    /**
+     * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder getSenderChainOrBuilder() {
+      return senderChain_;
+    }
+
+    // repeated .textsecure.SessionStructure.Chain receiverChains = 7;
+    public static final int RECEIVERCHAINS_FIELD_NUMBER = 7;
+    private java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain> receiverChains_;
+    /**
+     * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+     */
+    public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain> getReceiverChainsList() {
+      return receiverChains_;
+    }
+    /**
+     * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+     */
+    public java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder> 
+        getReceiverChainsOrBuilderList() {
+      return receiverChains_;
+    }
+    /**
+     * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+     */
+    public int getReceiverChainsCount() {
+      return receiverChains_.size();
+    }
+    /**
+     * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain getReceiverChains(int index) {
+      return receiverChains_.get(index);
+    }
+    /**
+     * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder getReceiverChainsOrBuilder(
+        int index) {
+      return receiverChains_.get(index);
+    }
+
+    // optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;
+    public static final int PENDINGKEYEXCHANGE_FIELD_NUMBER = 8;
+    private org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange pendingKeyExchange_;
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+     */
+    public boolean hasPendingKeyExchange() {
+      return ((bitField0_ & 0x00000040) == 0x00000040);
+    }
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange getPendingKeyExchange() {
+      return pendingKeyExchange_;
+    }
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchangeOrBuilder getPendingKeyExchangeOrBuilder() {
+      return pendingKeyExchange_;
+    }
+
+    // optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;
+    public static final int PENDINGPREKEY_FIELD_NUMBER = 9;
+    private org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey pendingPreKey_;
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+     */
+    public boolean hasPendingPreKey() {
+      return ((bitField0_ & 0x00000080) == 0x00000080);
+    }
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey getPendingPreKey() {
+      return pendingPreKey_;
+    }
+    /**
+     * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKeyOrBuilder getPendingPreKeyOrBuilder() {
+      return pendingPreKey_;
+    }
+
+    // optional uint32 remoteRegistrationId = 10;
+    public static final int REMOTEREGISTRATIONID_FIELD_NUMBER = 10;
+    private int remoteRegistrationId_;
+    /**
+     * <code>optional uint32 remoteRegistrationId = 10;</code>
+     */
+    public boolean hasRemoteRegistrationId() {
+      return ((bitField0_ & 0x00000100) == 0x00000100);
+    }
+    /**
+     * <code>optional uint32 remoteRegistrationId = 10;</code>
+     */
+    public int getRemoteRegistrationId() {
+      return remoteRegistrationId_;
+    }
+
+    // optional uint32 localRegistrationId = 11;
+    public static final int LOCALREGISTRATIONID_FIELD_NUMBER = 11;
+    private int localRegistrationId_;
+    /**
+     * <code>optional uint32 localRegistrationId = 11;</code>
+     */
+    public boolean hasLocalRegistrationId() {
+      return ((bitField0_ & 0x00000200) == 0x00000200);
+    }
+    /**
+     * <code>optional uint32 localRegistrationId = 11;</code>
+     */
+    public int getLocalRegistrationId() {
+      return localRegistrationId_;
+    }
+
+    // optional bool needsRefresh = 12;
+    public static final int NEEDSREFRESH_FIELD_NUMBER = 12;
+    private boolean needsRefresh_;
+    /**
+     * <code>optional bool needsRefresh = 12;</code>
+     */
+    public boolean hasNeedsRefresh() {
+      return ((bitField0_ & 0x00000400) == 0x00000400);
+    }
+    /**
+     * <code>optional bool needsRefresh = 12;</code>
+     */
+    public boolean getNeedsRefresh() {
+      return needsRefresh_;
+    }
+
+    // optional bytes aliceBaseKey = 13;
+    public static final int ALICEBASEKEY_FIELD_NUMBER = 13;
+    private com.google.protobuf.ByteString aliceBaseKey_;
+    /**
+     * <code>optional bytes aliceBaseKey = 13;</code>
+     */
+    public boolean hasAliceBaseKey() {
+      return ((bitField0_ & 0x00000800) == 0x00000800);
+    }
+    /**
+     * <code>optional bytes aliceBaseKey = 13;</code>
+     */
+    public com.google.protobuf.ByteString getAliceBaseKey() {
+      return aliceBaseKey_;
+    }
+
+    private void initFields() {
+      sessionVersion_ = 0;
+      localIdentityPublic_ = com.google.protobuf.ByteString.EMPTY;
+      remoteIdentityPublic_ = com.google.protobuf.ByteString.EMPTY;
+      rootKey_ = com.google.protobuf.ByteString.EMPTY;
+      previousCounter_ = 0;
+      senderChain_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.getDefaultInstance();
+      receiverChains_ = java.util.Collections.emptyList();
+      pendingKeyExchange_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.getDefaultInstance();
+      pendingPreKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.getDefaultInstance();
+      remoteRegistrationId_ = 0;
+      localRegistrationId_ = 0;
+      needsRefresh_ = false;
+      aliceBaseKey_ = com.google.protobuf.ByteString.EMPTY;
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeUInt32(1, sessionVersion_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeBytes(2, localIdentityPublic_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeBytes(3, remoteIdentityPublic_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        output.writeBytes(4, rootKey_);
+      }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        output.writeUInt32(5, previousCounter_);
+      }
+      if (((bitField0_ & 0x00000020) == 0x00000020)) {
+        output.writeMessage(6, senderChain_);
+      }
+      for (int i = 0; i < receiverChains_.size(); i++) {
+        output.writeMessage(7, receiverChains_.get(i));
+      }
+      if (((bitField0_ & 0x00000040) == 0x00000040)) {
+        output.writeMessage(8, pendingKeyExchange_);
+      }
+      if (((bitField0_ & 0x00000080) == 0x00000080)) {
+        output.writeMessage(9, pendingPreKey_);
+      }
+      if (((bitField0_ & 0x00000100) == 0x00000100)) {
+        output.writeUInt32(10, remoteRegistrationId_);
+      }
+      if (((bitField0_ & 0x00000200) == 0x00000200)) {
+        output.writeUInt32(11, localRegistrationId_);
+      }
+      if (((bitField0_ & 0x00000400) == 0x00000400)) {
+        output.writeBool(12, needsRefresh_);
+      }
+      if (((bitField0_ & 0x00000800) == 0x00000800)) {
+        output.writeBytes(13, aliceBaseKey_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(1, sessionVersion_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(2, localIdentityPublic_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(3, remoteIdentityPublic_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(4, rootKey_);
+      }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(5, previousCounter_);
+      }
+      if (((bitField0_ & 0x00000020) == 0x00000020)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(6, senderChain_);
+      }
+      for (int i = 0; i < receiverChains_.size(); i++) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(7, receiverChains_.get(i));
+      }
+      if (((bitField0_ & 0x00000040) == 0x00000040)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(8, pendingKeyExchange_);
+      }
+      if (((bitField0_ & 0x00000080) == 0x00000080)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(9, pendingPreKey_);
+      }
+      if (((bitField0_ & 0x00000100) == 0x00000100)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(10, remoteRegistrationId_);
+      }
+      if (((bitField0_ & 0x00000200) == 0x00000200)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(11, localRegistrationId_);
+      }
+      if (((bitField0_ & 0x00000400) == 0x00000400)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBoolSize(12, needsRefresh_);
+      }
+      if (((bitField0_ & 0x00000800) == 0x00000800)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(13, aliceBaseKey_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.SessionStructure}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+          getSenderChainFieldBuilder();
+          getReceiverChainsFieldBuilder();
+          getPendingKeyExchangeFieldBuilder();
+          getPendingPreKeyFieldBuilder();
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        sessionVersion_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        localIdentityPublic_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000002);
+        remoteIdentityPublic_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000004);
+        rootKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000008);
+        previousCounter_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000010);
+        if (senderChainBuilder_ == null) {
+          senderChain_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.getDefaultInstance();
+        } else {
+          senderChainBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000020);
+        if (receiverChainsBuilder_ == null) {
+          receiverChains_ = java.util.Collections.emptyList();
+          bitField0_ = (bitField0_ & ~0x00000040);
+        } else {
+          receiverChainsBuilder_.clear();
+        }
+        if (pendingKeyExchangeBuilder_ == null) {
+          pendingKeyExchange_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.getDefaultInstance();
+        } else {
+          pendingKeyExchangeBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000080);
+        if (pendingPreKeyBuilder_ == null) {
+          pendingPreKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.getDefaultInstance();
+        } else {
+          pendingPreKeyBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000100);
+        remoteRegistrationId_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000200);
+        localRegistrationId_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000400);
+        needsRefresh_ = false;
+        bitField0_ = (bitField0_ & ~0x00000800);
+        aliceBaseKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00001000);
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SessionStructure_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure build() {
+        org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure buildPartial() {
+        org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure result = new org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.sessionVersion_ = sessionVersion_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        result.localIdentityPublic_ = localIdentityPublic_;
+        if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        result.remoteIdentityPublic_ = remoteIdentityPublic_;
+        if (((from_bitField0_ & 0x00000008) == 0x00000008)) {
+          to_bitField0_ |= 0x00000008;
+        }
+        result.rootKey_ = rootKey_;
+        if (((from_bitField0_ & 0x00000010) == 0x00000010)) {
+          to_bitField0_ |= 0x00000010;
+        }
+        result.previousCounter_ = previousCounter_;
+        if (((from_bitField0_ & 0x00000020) == 0x00000020)) {
+          to_bitField0_ |= 0x00000020;
+        }
+        if (senderChainBuilder_ == null) {
+          result.senderChain_ = senderChain_;
+        } else {
+          result.senderChain_ = senderChainBuilder_.build();
+        }
+        if (receiverChainsBuilder_ == null) {
+          if (((bitField0_ & 0x00000040) == 0x00000040)) {
+            receiverChains_ = java.util.Collections.unmodifiableList(receiverChains_);
+            bitField0_ = (bitField0_ & ~0x00000040);
+          }
+          result.receiverChains_ = receiverChains_;
+        } else {
+          result.receiverChains_ = receiverChainsBuilder_.build();
+        }
+        if (((from_bitField0_ & 0x00000080) == 0x00000080)) {
+          to_bitField0_ |= 0x00000040;
+        }
+        if (pendingKeyExchangeBuilder_ == null) {
+          result.pendingKeyExchange_ = pendingKeyExchange_;
+        } else {
+          result.pendingKeyExchange_ = pendingKeyExchangeBuilder_.build();
+        }
+        if (((from_bitField0_ & 0x00000100) == 0x00000100)) {
+          to_bitField0_ |= 0x00000080;
+        }
+        if (pendingPreKeyBuilder_ == null) {
+          result.pendingPreKey_ = pendingPreKey_;
+        } else {
+          result.pendingPreKey_ = pendingPreKeyBuilder_.build();
+        }
+        if (((from_bitField0_ & 0x00000200) == 0x00000200)) {
+          to_bitField0_ |= 0x00000100;
+        }
+        result.remoteRegistrationId_ = remoteRegistrationId_;
+        if (((from_bitField0_ & 0x00000400) == 0x00000400)) {
+          to_bitField0_ |= 0x00000200;
+        }
+        result.localRegistrationId_ = localRegistrationId_;
+        if (((from_bitField0_ & 0x00000800) == 0x00000800)) {
+          to_bitField0_ |= 0x00000400;
+        }
+        result.needsRefresh_ = needsRefresh_;
+        if (((from_bitField0_ & 0x00001000) == 0x00001000)) {
+          to_bitField0_ |= 0x00000800;
+        }
+        result.aliceBaseKey_ = aliceBaseKey_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure) {
+          return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure other) {
+        if (other == org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.getDefaultInstance()) return this;
+        if (other.hasSessionVersion()) {
+          setSessionVersion(other.getSessionVersion());
+        }
+        if (other.hasLocalIdentityPublic()) {
+          setLocalIdentityPublic(other.getLocalIdentityPublic());
+        }
+        if (other.hasRemoteIdentityPublic()) {
+          setRemoteIdentityPublic(other.getRemoteIdentityPublic());
+        }
+        if (other.hasRootKey()) {
+          setRootKey(other.getRootKey());
+        }
+        if (other.hasPreviousCounter()) {
+          setPreviousCounter(other.getPreviousCounter());
+        }
+        if (other.hasSenderChain()) {
+          mergeSenderChain(other.getSenderChain());
+        }
+        if (receiverChainsBuilder_ == null) {
+          if (!other.receiverChains_.isEmpty()) {
+            if (receiverChains_.isEmpty()) {
+              receiverChains_ = other.receiverChains_;
+              bitField0_ = (bitField0_ & ~0x00000040);
+            } else {
+              ensureReceiverChainsIsMutable();
+              receiverChains_.addAll(other.receiverChains_);
+            }
+            onChanged();
+          }
+        } else {
+          if (!other.receiverChains_.isEmpty()) {
+            if (receiverChainsBuilder_.isEmpty()) {
+              receiverChainsBuilder_.dispose();
+              receiverChainsBuilder_ = null;
+              receiverChains_ = other.receiverChains_;
+              bitField0_ = (bitField0_ & ~0x00000040);
+              receiverChainsBuilder_ = 
+                com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders ?
+                   getReceiverChainsFieldBuilder() : null;
+            } else {
+              receiverChainsBuilder_.addAllMessages(other.receiverChains_);
+            }
+          }
+        }
+        if (other.hasPendingKeyExchange()) {
+          mergePendingKeyExchange(other.getPendingKeyExchange());
+        }
+        if (other.hasPendingPreKey()) {
+          mergePendingPreKey(other.getPendingPreKey());
+        }
+        if (other.hasRemoteRegistrationId()) {
+          setRemoteRegistrationId(other.getRemoteRegistrationId());
+        }
+        if (other.hasLocalRegistrationId()) {
+          setLocalRegistrationId(other.getLocalRegistrationId());
+        }
+        if (other.hasNeedsRefresh()) {
+          setNeedsRefresh(other.getNeedsRefresh());
+        }
+        if (other.hasAliceBaseKey()) {
+          setAliceBaseKey(other.getAliceBaseKey());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional uint32 sessionVersion = 1;
+      private int sessionVersion_ ;
+      /**
+       * <code>optional uint32 sessionVersion = 1;</code>
+       */
+      public boolean hasSessionVersion() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional uint32 sessionVersion = 1;</code>
+       */
+      public int getSessionVersion() {
+        return sessionVersion_;
+      }
+      /**
+       * <code>optional uint32 sessionVersion = 1;</code>
+       */
+      public Builder setSessionVersion(int value) {
+        bitField0_ |= 0x00000001;
+        sessionVersion_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 sessionVersion = 1;</code>
+       */
+      public Builder clearSessionVersion() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        sessionVersion_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional bytes localIdentityPublic = 2;
+      private com.google.protobuf.ByteString localIdentityPublic_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes localIdentityPublic = 2;</code>
+       */
+      public boolean hasLocalIdentityPublic() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional bytes localIdentityPublic = 2;</code>
+       */
+      public com.google.protobuf.ByteString getLocalIdentityPublic() {
+        return localIdentityPublic_;
+      }
+      /**
+       * <code>optional bytes localIdentityPublic = 2;</code>
+       */
+      public Builder setLocalIdentityPublic(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+        localIdentityPublic_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes localIdentityPublic = 2;</code>
+       */
+      public Builder clearLocalIdentityPublic() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        localIdentityPublic_ = getDefaultInstance().getLocalIdentityPublic();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes remoteIdentityPublic = 3;
+      private com.google.protobuf.ByteString remoteIdentityPublic_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes remoteIdentityPublic = 3;</code>
+       */
+      public boolean hasRemoteIdentityPublic() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional bytes remoteIdentityPublic = 3;</code>
+       */
+      public com.google.protobuf.ByteString getRemoteIdentityPublic() {
+        return remoteIdentityPublic_;
+      }
+      /**
+       * <code>optional bytes remoteIdentityPublic = 3;</code>
+       */
+      public Builder setRemoteIdentityPublic(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000004;
+        remoteIdentityPublic_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes remoteIdentityPublic = 3;</code>
+       */
+      public Builder clearRemoteIdentityPublic() {
+        bitField0_ = (bitField0_ & ~0x00000004);
+        remoteIdentityPublic_ = getDefaultInstance().getRemoteIdentityPublic();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes rootKey = 4;
+      private com.google.protobuf.ByteString rootKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes rootKey = 4;</code>
+       */
+      public boolean hasRootKey() {
+        return ((bitField0_ & 0x00000008) == 0x00000008);
+      }
+      /**
+       * <code>optional bytes rootKey = 4;</code>
+       */
+      public com.google.protobuf.ByteString getRootKey() {
+        return rootKey_;
+      }
+      /**
+       * <code>optional bytes rootKey = 4;</code>
+       */
+      public Builder setRootKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000008;
+        rootKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes rootKey = 4;</code>
+       */
+      public Builder clearRootKey() {
+        bitField0_ = (bitField0_ & ~0x00000008);
+        rootKey_ = getDefaultInstance().getRootKey();
+        onChanged();
+        return this;
+      }
+
+      // optional uint32 previousCounter = 5;
+      private int previousCounter_ ;
+      /**
+       * <code>optional uint32 previousCounter = 5;</code>
+       */
+      public boolean hasPreviousCounter() {
+        return ((bitField0_ & 0x00000010) == 0x00000010);
+      }
+      /**
+       * <code>optional uint32 previousCounter = 5;</code>
+       */
+      public int getPreviousCounter() {
+        return previousCounter_;
+      }
+      /**
+       * <code>optional uint32 previousCounter = 5;</code>
+       */
+      public Builder setPreviousCounter(int value) {
+        bitField0_ |= 0x00000010;
+        previousCounter_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 previousCounter = 5;</code>
+       */
+      public Builder clearPreviousCounter() {
+        bitField0_ = (bitField0_ & ~0x00000010);
+        previousCounter_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional .textsecure.SessionStructure.Chain senderChain = 6;
+      private org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain senderChain_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.getDefaultInstance();
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder> senderChainBuilder_;
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+       */
+      public boolean hasSenderChain() {
+        return ((bitField0_ & 0x00000020) == 0x00000020);
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain getSenderChain() {
+        if (senderChainBuilder_ == null) {
+          return senderChain_;
+        } else {
+          return senderChainBuilder_.getMessage();
+        }
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+       */
+      public Builder setSenderChain(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain value) {
+        if (senderChainBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          senderChain_ = value;
+          onChanged();
+        } else {
+          senderChainBuilder_.setMessage(value);
+        }
+        bitField0_ |= 0x00000020;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+       */
+      public Builder setSenderChain(
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder builderForValue) {
+        if (senderChainBuilder_ == null) {
+          senderChain_ = builderForValue.build();
+          onChanged();
+        } else {
+          senderChainBuilder_.setMessage(builderForValue.build());
+        }
+        bitField0_ |= 0x00000020;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+       */
+      public Builder mergeSenderChain(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain value) {
+        if (senderChainBuilder_ == null) {
+          if (((bitField0_ & 0x00000020) == 0x00000020) &&
+              senderChain_ != org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.getDefaultInstance()) {
+            senderChain_ =
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.newBuilder(senderChain_).mergeFrom(value).buildPartial();
+          } else {
+            senderChain_ = value;
+          }
+          onChanged();
+        } else {
+          senderChainBuilder_.mergeFrom(value);
+        }
+        bitField0_ |= 0x00000020;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+       */
+      public Builder clearSenderChain() {
+        if (senderChainBuilder_ == null) {
+          senderChain_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.getDefaultInstance();
+          onChanged();
+        } else {
+          senderChainBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000020);
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder getSenderChainBuilder() {
+        bitField0_ |= 0x00000020;
+        onChanged();
+        return getSenderChainFieldBuilder().getBuilder();
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder getSenderChainOrBuilder() {
+        if (senderChainBuilder_ != null) {
+          return senderChainBuilder_.getMessageOrBuilder();
+        } else {
+          return senderChain_;
+        }
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.Chain senderChain = 6;</code>
+       */
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder> 
+          getSenderChainFieldBuilder() {
+        if (senderChainBuilder_ == null) {
+          senderChainBuilder_ = new com.google.protobuf.SingleFieldBuilder<
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder>(
+                  senderChain_,
+                  getParentForChildren(),
+                  isClean());
+          senderChain_ = null;
+        }
+        return senderChainBuilder_;
+      }
+
+      // repeated .textsecure.SessionStructure.Chain receiverChains = 7;
+      private java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain> receiverChains_ =
+        java.util.Collections.emptyList();
+      private void ensureReceiverChainsIsMutable() {
+        if (!((bitField0_ & 0x00000040) == 0x00000040)) {
+          receiverChains_ = new java.util.ArrayList<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain>(receiverChains_);
+          bitField0_ |= 0x00000040;
+         }
+      }
+
+      private com.google.protobuf.RepeatedFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder> receiverChainsBuilder_;
+
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain> getReceiverChainsList() {
+        if (receiverChainsBuilder_ == null) {
+          return java.util.Collections.unmodifiableList(receiverChains_);
+        } else {
+          return receiverChainsBuilder_.getMessageList();
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public int getReceiverChainsCount() {
+        if (receiverChainsBuilder_ == null) {
+          return receiverChains_.size();
+        } else {
+          return receiverChainsBuilder_.getCount();
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain getReceiverChains(int index) {
+        if (receiverChainsBuilder_ == null) {
+          return receiverChains_.get(index);
+        } else {
+          return receiverChainsBuilder_.getMessage(index);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public Builder setReceiverChains(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain value) {
+        if (receiverChainsBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensureReceiverChainsIsMutable();
+          receiverChains_.set(index, value);
+          onChanged();
+        } else {
+          receiverChainsBuilder_.setMessage(index, value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public Builder setReceiverChains(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder builderForValue) {
+        if (receiverChainsBuilder_ == null) {
+          ensureReceiverChainsIsMutable();
+          receiverChains_.set(index, builderForValue.build());
+          onChanged();
+        } else {
+          receiverChainsBuilder_.setMessage(index, builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public Builder addReceiverChains(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain value) {
+        if (receiverChainsBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensureReceiverChainsIsMutable();
+          receiverChains_.add(value);
+          onChanged();
+        } else {
+          receiverChainsBuilder_.addMessage(value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public Builder addReceiverChains(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain value) {
+        if (receiverChainsBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensureReceiverChainsIsMutable();
+          receiverChains_.add(index, value);
+          onChanged();
+        } else {
+          receiverChainsBuilder_.addMessage(index, value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public Builder addReceiverChains(
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder builderForValue) {
+        if (receiverChainsBuilder_ == null) {
+          ensureReceiverChainsIsMutable();
+          receiverChains_.add(builderForValue.build());
+          onChanged();
+        } else {
+          receiverChainsBuilder_.addMessage(builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public Builder addReceiverChains(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder builderForValue) {
+        if (receiverChainsBuilder_ == null) {
+          ensureReceiverChainsIsMutable();
+          receiverChains_.add(index, builderForValue.build());
+          onChanged();
+        } else {
+          receiverChainsBuilder_.addMessage(index, builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public Builder addAllReceiverChains(
+          java.lang.Iterable<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain> values) {
+        if (receiverChainsBuilder_ == null) {
+          ensureReceiverChainsIsMutable();
+          super.addAll(values, receiverChains_);
+          onChanged();
+        } else {
+          receiverChainsBuilder_.addAllMessages(values);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public Builder clearReceiverChains() {
+        if (receiverChainsBuilder_ == null) {
+          receiverChains_ = java.util.Collections.emptyList();
+          bitField0_ = (bitField0_ & ~0x00000040);
+          onChanged();
+        } else {
+          receiverChainsBuilder_.clear();
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public Builder removeReceiverChains(int index) {
+        if (receiverChainsBuilder_ == null) {
+          ensureReceiverChainsIsMutable();
+          receiverChains_.remove(index);
+          onChanged();
+        } else {
+          receiverChainsBuilder_.remove(index);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder getReceiverChainsBuilder(
+          int index) {
+        return getReceiverChainsFieldBuilder().getBuilder(index);
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder getReceiverChainsOrBuilder(
+          int index) {
+        if (receiverChainsBuilder_ == null) {
+          return receiverChains_.get(index);  } else {
+          return receiverChainsBuilder_.getMessageOrBuilder(index);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder> 
+           getReceiverChainsOrBuilderList() {
+        if (receiverChainsBuilder_ != null) {
+          return receiverChainsBuilder_.getMessageOrBuilderList();
+        } else {
+          return java.util.Collections.unmodifiableList(receiverChains_);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder addReceiverChainsBuilder() {
+        return getReceiverChainsFieldBuilder().addBuilder(
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.getDefaultInstance());
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder addReceiverChainsBuilder(
+          int index) {
+        return getReceiverChainsFieldBuilder().addBuilder(
+            index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.getDefaultInstance());
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure.Chain receiverChains = 7;</code>
+       */
+      public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder> 
+           getReceiverChainsBuilderList() {
+        return getReceiverChainsFieldBuilder().getBuilderList();
+      }
+      private com.google.protobuf.RepeatedFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder> 
+          getReceiverChainsFieldBuilder() {
+        if (receiverChainsBuilder_ == null) {
+          receiverChainsBuilder_ = new com.google.protobuf.RepeatedFieldBuilder<
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Chain.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.ChainOrBuilder>(
+                  receiverChains_,
+                  ((bitField0_ & 0x00000040) == 0x00000040),
+                  getParentForChildren(),
+                  isClean());
+          receiverChains_ = null;
+        }
+        return receiverChainsBuilder_;
+      }
+
+      // optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;
+      private org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange pendingKeyExchange_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.getDefaultInstance();
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchangeOrBuilder> pendingKeyExchangeBuilder_;
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+       */
+      public boolean hasPendingKeyExchange() {
+        return ((bitField0_ & 0x00000080) == 0x00000080);
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange getPendingKeyExchange() {
+        if (pendingKeyExchangeBuilder_ == null) {
+          return pendingKeyExchange_;
+        } else {
+          return pendingKeyExchangeBuilder_.getMessage();
+        }
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+       */
+      public Builder setPendingKeyExchange(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange value) {
+        if (pendingKeyExchangeBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          pendingKeyExchange_ = value;
+          onChanged();
+        } else {
+          pendingKeyExchangeBuilder_.setMessage(value);
+        }
+        bitField0_ |= 0x00000080;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+       */
+      public Builder setPendingKeyExchange(
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.Builder builderForValue) {
+        if (pendingKeyExchangeBuilder_ == null) {
+          pendingKeyExchange_ = builderForValue.build();
+          onChanged();
+        } else {
+          pendingKeyExchangeBuilder_.setMessage(builderForValue.build());
+        }
+        bitField0_ |= 0x00000080;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+       */
+      public Builder mergePendingKeyExchange(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange value) {
+        if (pendingKeyExchangeBuilder_ == null) {
+          if (((bitField0_ & 0x00000080) == 0x00000080) &&
+              pendingKeyExchange_ != org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.getDefaultInstance()) {
+            pendingKeyExchange_ =
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.newBuilder(pendingKeyExchange_).mergeFrom(value).buildPartial();
+          } else {
+            pendingKeyExchange_ = value;
+          }
+          onChanged();
+        } else {
+          pendingKeyExchangeBuilder_.mergeFrom(value);
+        }
+        bitField0_ |= 0x00000080;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+       */
+      public Builder clearPendingKeyExchange() {
+        if (pendingKeyExchangeBuilder_ == null) {
+          pendingKeyExchange_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.getDefaultInstance();
+          onChanged();
+        } else {
+          pendingKeyExchangeBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000080);
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.Builder getPendingKeyExchangeBuilder() {
+        bitField0_ |= 0x00000080;
+        onChanged();
+        return getPendingKeyExchangeFieldBuilder().getBuilder();
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchangeOrBuilder getPendingKeyExchangeOrBuilder() {
+        if (pendingKeyExchangeBuilder_ != null) {
+          return pendingKeyExchangeBuilder_.getMessageOrBuilder();
+        } else {
+          return pendingKeyExchange_;
+        }
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingKeyExchange pendingKeyExchange = 8;</code>
+       */
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchangeOrBuilder> 
+          getPendingKeyExchangeFieldBuilder() {
+        if (pendingKeyExchangeBuilder_ == null) {
+          pendingKeyExchangeBuilder_ = new com.google.protobuf.SingleFieldBuilder<
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchange.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingKeyExchangeOrBuilder>(
+                  pendingKeyExchange_,
+                  getParentForChildren(),
+                  isClean());
+          pendingKeyExchange_ = null;
+        }
+        return pendingKeyExchangeBuilder_;
+      }
+
+      // optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;
+      private org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey pendingPreKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.getDefaultInstance();
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKeyOrBuilder> pendingPreKeyBuilder_;
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+       */
+      public boolean hasPendingPreKey() {
+        return ((bitField0_ & 0x00000100) == 0x00000100);
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey getPendingPreKey() {
+        if (pendingPreKeyBuilder_ == null) {
+          return pendingPreKey_;
+        } else {
+          return pendingPreKeyBuilder_.getMessage();
+        }
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+       */
+      public Builder setPendingPreKey(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey value) {
+        if (pendingPreKeyBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          pendingPreKey_ = value;
+          onChanged();
+        } else {
+          pendingPreKeyBuilder_.setMessage(value);
+        }
+        bitField0_ |= 0x00000100;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+       */
+      public Builder setPendingPreKey(
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.Builder builderForValue) {
+        if (pendingPreKeyBuilder_ == null) {
+          pendingPreKey_ = builderForValue.build();
+          onChanged();
+        } else {
+          pendingPreKeyBuilder_.setMessage(builderForValue.build());
+        }
+        bitField0_ |= 0x00000100;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+       */
+      public Builder mergePendingPreKey(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey value) {
+        if (pendingPreKeyBuilder_ == null) {
+          if (((bitField0_ & 0x00000100) == 0x00000100) &&
+              pendingPreKey_ != org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.getDefaultInstance()) {
+            pendingPreKey_ =
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.newBuilder(pendingPreKey_).mergeFrom(value).buildPartial();
+          } else {
+            pendingPreKey_ = value;
+          }
+          onChanged();
+        } else {
+          pendingPreKeyBuilder_.mergeFrom(value);
+        }
+        bitField0_ |= 0x00000100;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+       */
+      public Builder clearPendingPreKey() {
+        if (pendingPreKeyBuilder_ == null) {
+          pendingPreKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.getDefaultInstance();
+          onChanged();
+        } else {
+          pendingPreKeyBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000100);
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.Builder getPendingPreKeyBuilder() {
+        bitField0_ |= 0x00000100;
+        onChanged();
+        return getPendingPreKeyFieldBuilder().getBuilder();
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKeyOrBuilder getPendingPreKeyOrBuilder() {
+        if (pendingPreKeyBuilder_ != null) {
+          return pendingPreKeyBuilder_.getMessageOrBuilder();
+        } else {
+          return pendingPreKey_;
+        }
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure.PendingPreKey pendingPreKey = 9;</code>
+       */
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKeyOrBuilder> 
+          getPendingPreKeyFieldBuilder() {
+        if (pendingPreKeyBuilder_ == null) {
+          pendingPreKeyBuilder_ = new com.google.protobuf.SingleFieldBuilder<
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PendingPreKeyOrBuilder>(
+                  pendingPreKey_,
+                  getParentForChildren(),
+                  isClean());
+          pendingPreKey_ = null;
+        }
+        return pendingPreKeyBuilder_;
+      }
+
+      // optional uint32 remoteRegistrationId = 10;
+      private int remoteRegistrationId_ ;
+      /**
+       * <code>optional uint32 remoteRegistrationId = 10;</code>
+       */
+      public boolean hasRemoteRegistrationId() {
+        return ((bitField0_ & 0x00000200) == 0x00000200);
+      }
+      /**
+       * <code>optional uint32 remoteRegistrationId = 10;</code>
+       */
+      public int getRemoteRegistrationId() {
+        return remoteRegistrationId_;
+      }
+      /**
+       * <code>optional uint32 remoteRegistrationId = 10;</code>
+       */
+      public Builder setRemoteRegistrationId(int value) {
+        bitField0_ |= 0x00000200;
+        remoteRegistrationId_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 remoteRegistrationId = 10;</code>
+       */
+      public Builder clearRemoteRegistrationId() {
+        bitField0_ = (bitField0_ & ~0x00000200);
+        remoteRegistrationId_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional uint32 localRegistrationId = 11;
+      private int localRegistrationId_ ;
+      /**
+       * <code>optional uint32 localRegistrationId = 11;</code>
+       */
+      public boolean hasLocalRegistrationId() {
+        return ((bitField0_ & 0x00000400) == 0x00000400);
+      }
+      /**
+       * <code>optional uint32 localRegistrationId = 11;</code>
+       */
+      public int getLocalRegistrationId() {
+        return localRegistrationId_;
+      }
+      /**
+       * <code>optional uint32 localRegistrationId = 11;</code>
+       */
+      public Builder setLocalRegistrationId(int value) {
+        bitField0_ |= 0x00000400;
+        localRegistrationId_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 localRegistrationId = 11;</code>
+       */
+      public Builder clearLocalRegistrationId() {
+        bitField0_ = (bitField0_ & ~0x00000400);
+        localRegistrationId_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional bool needsRefresh = 12;
+      private boolean needsRefresh_ ;
+      /**
+       * <code>optional bool needsRefresh = 12;</code>
+       */
+      public boolean hasNeedsRefresh() {
+        return ((bitField0_ & 0x00000800) == 0x00000800);
+      }
+      /**
+       * <code>optional bool needsRefresh = 12;</code>
+       */
+      public boolean getNeedsRefresh() {
+        return needsRefresh_;
+      }
+      /**
+       * <code>optional bool needsRefresh = 12;</code>
+       */
+      public Builder setNeedsRefresh(boolean value) {
+        bitField0_ |= 0x00000800;
+        needsRefresh_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bool needsRefresh = 12;</code>
+       */
+      public Builder clearNeedsRefresh() {
+        bitField0_ = (bitField0_ & ~0x00000800);
+        needsRefresh_ = false;
+        onChanged();
+        return this;
+      }
+
+      // optional bytes aliceBaseKey = 13;
+      private com.google.protobuf.ByteString aliceBaseKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes aliceBaseKey = 13;</code>
+       */
+      public boolean hasAliceBaseKey() {
+        return ((bitField0_ & 0x00001000) == 0x00001000);
+      }
+      /**
+       * <code>optional bytes aliceBaseKey = 13;</code>
+       */
+      public com.google.protobuf.ByteString getAliceBaseKey() {
+        return aliceBaseKey_;
+      }
+      /**
+       * <code>optional bytes aliceBaseKey = 13;</code>
+       */
+      public Builder setAliceBaseKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00001000;
+        aliceBaseKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes aliceBaseKey = 13;</code>
+       */
+      public Builder clearAliceBaseKey() {
+        bitField0_ = (bitField0_ & ~0x00001000);
+        aliceBaseKey_ = getDefaultInstance().getAliceBaseKey();
+        onChanged();
+        return this;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.SessionStructure)
+    }
+
+    static {
+      defaultInstance = new SessionStructure(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.SessionStructure)
+  }
+
+  public interface RecordStructureOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional .textsecure.SessionStructure currentSession = 1;
+    /**
+     * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+     */
+    boolean hasCurrentSession();
+    /**
+     * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure getCurrentSession();
+    /**
+     * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder getCurrentSessionOrBuilder();
+
+    // repeated .textsecure.SessionStructure previousSessions = 2;
+    /**
+     * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+     */
+    java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure> 
+        getPreviousSessionsList();
+    /**
+     * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure getPreviousSessions(int index);
+    /**
+     * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+     */
+    int getPreviousSessionsCount();
+    /**
+     * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+     */
+    java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder> 
+        getPreviousSessionsOrBuilderList();
+    /**
+     * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder getPreviousSessionsOrBuilder(
+        int index);
+  }
+  /**
+   * Protobuf type {@code textsecure.RecordStructure}
+   */
+  public static final class RecordStructure extends
+      com.google.protobuf.GeneratedMessage
+      implements RecordStructureOrBuilder {
+    // Use RecordStructure.newBuilder() to construct.
+    private RecordStructure(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private RecordStructure(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final RecordStructure defaultInstance;
+    public static RecordStructure getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public RecordStructure getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private RecordStructure(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 10: {
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder subBuilder = null;
+              if (((bitField0_ & 0x00000001) == 0x00000001)) {
+                subBuilder = currentSession_.toBuilder();
+              }
+              currentSession_ = input.readMessage(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PARSER, extensionRegistry);
+              if (subBuilder != null) {
+                subBuilder.mergeFrom(currentSession_);
+                currentSession_ = subBuilder.buildPartial();
+              }
+              bitField0_ |= 0x00000001;
+              break;
+            }
+            case 18: {
+              if (!((mutable_bitField0_ & 0x00000002) == 0x00000002)) {
+                previousSessions_ = new java.util.ArrayList<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure>();
+                mutable_bitField0_ |= 0x00000002;
+              }
+              previousSessions_.add(input.readMessage(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.PARSER, extensionRegistry));
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        if (((mutable_bitField0_ & 0x00000002) == 0x00000002)) {
+          previousSessions_ = java.util.Collections.unmodifiableList(previousSessions_);
+        }
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_RecordStructure_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_RecordStructure_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<RecordStructure> PARSER =
+        new com.google.protobuf.AbstractParser<RecordStructure>() {
+      public RecordStructure parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new RecordStructure(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<RecordStructure> getParserForType() {
+      return PARSER;
+    }
+
+    private int bitField0_;
+    // optional .textsecure.SessionStructure currentSession = 1;
+    public static final int CURRENTSESSION_FIELD_NUMBER = 1;
+    private org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure currentSession_;
+    /**
+     * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+     */
+    public boolean hasCurrentSession() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure getCurrentSession() {
+      return currentSession_;
+    }
+    /**
+     * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder getCurrentSessionOrBuilder() {
+      return currentSession_;
+    }
+
+    // repeated .textsecure.SessionStructure previousSessions = 2;
+    public static final int PREVIOUSSESSIONS_FIELD_NUMBER = 2;
+    private java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure> previousSessions_;
+    /**
+     * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+     */
+    public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure> getPreviousSessionsList() {
+      return previousSessions_;
+    }
+    /**
+     * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+     */
+    public java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder> 
+        getPreviousSessionsOrBuilderList() {
+      return previousSessions_;
+    }
+    /**
+     * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+     */
+    public int getPreviousSessionsCount() {
+      return previousSessions_.size();
+    }
+    /**
+     * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure getPreviousSessions(int index) {
+      return previousSessions_.get(index);
+    }
+    /**
+     * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder getPreviousSessionsOrBuilder(
+        int index) {
+      return previousSessions_.get(index);
+    }
+
+    private void initFields() {
+      currentSession_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.getDefaultInstance();
+      previousSessions_ = java.util.Collections.emptyList();
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeMessage(1, currentSession_);
+      }
+      for (int i = 0; i < previousSessions_.size(); i++) {
+        output.writeMessage(2, previousSessions_.get(i));
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(1, currentSession_);
+      }
+      for (int i = 0; i < previousSessions_.size(); i++) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(2, previousSessions_.get(i));
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.RecordStructure}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.state.StorageProtos.RecordStructureOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_RecordStructure_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_RecordStructure_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+          getCurrentSessionFieldBuilder();
+          getPreviousSessionsFieldBuilder();
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        if (currentSessionBuilder_ == null) {
+          currentSession_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.getDefaultInstance();
+        } else {
+          currentSessionBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000001);
+        if (previousSessionsBuilder_ == null) {
+          previousSessions_ = java.util.Collections.emptyList();
+          bitField0_ = (bitField0_ & ~0x00000002);
+        } else {
+          previousSessionsBuilder_.clear();
+        }
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_RecordStructure_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure build() {
+        org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure buildPartial() {
+        org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure result = new org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        if (currentSessionBuilder_ == null) {
+          result.currentSession_ = currentSession_;
+        } else {
+          result.currentSession_ = currentSessionBuilder_.build();
+        }
+        if (previousSessionsBuilder_ == null) {
+          if (((bitField0_ & 0x00000002) == 0x00000002)) {
+            previousSessions_ = java.util.Collections.unmodifiableList(previousSessions_);
+            bitField0_ = (bitField0_ & ~0x00000002);
+          }
+          result.previousSessions_ = previousSessions_;
+        } else {
+          result.previousSessions_ = previousSessionsBuilder_.build();
+        }
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure) {
+          return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure other) {
+        if (other == org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure.getDefaultInstance()) return this;
+        if (other.hasCurrentSession()) {
+          mergeCurrentSession(other.getCurrentSession());
+        }
+        if (previousSessionsBuilder_ == null) {
+          if (!other.previousSessions_.isEmpty()) {
+            if (previousSessions_.isEmpty()) {
+              previousSessions_ = other.previousSessions_;
+              bitField0_ = (bitField0_ & ~0x00000002);
+            } else {
+              ensurePreviousSessionsIsMutable();
+              previousSessions_.addAll(other.previousSessions_);
+            }
+            onChanged();
+          }
+        } else {
+          if (!other.previousSessions_.isEmpty()) {
+            if (previousSessionsBuilder_.isEmpty()) {
+              previousSessionsBuilder_.dispose();
+              previousSessionsBuilder_ = null;
+              previousSessions_ = other.previousSessions_;
+              bitField0_ = (bitField0_ & ~0x00000002);
+              previousSessionsBuilder_ = 
+                com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders ?
+                   getPreviousSessionsFieldBuilder() : null;
+            } else {
+              previousSessionsBuilder_.addAllMessages(other.previousSessions_);
+            }
+          }
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.RecordStructure) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional .textsecure.SessionStructure currentSession = 1;
+      private org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure currentSession_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.getDefaultInstance();
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder> currentSessionBuilder_;
+      /**
+       * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+       */
+      public boolean hasCurrentSession() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure getCurrentSession() {
+        if (currentSessionBuilder_ == null) {
+          return currentSession_;
+        } else {
+          return currentSessionBuilder_.getMessage();
+        }
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+       */
+      public Builder setCurrentSession(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure value) {
+        if (currentSessionBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          currentSession_ = value;
+          onChanged();
+        } else {
+          currentSessionBuilder_.setMessage(value);
+        }
+        bitField0_ |= 0x00000001;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+       */
+      public Builder setCurrentSession(
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder builderForValue) {
+        if (currentSessionBuilder_ == null) {
+          currentSession_ = builderForValue.build();
+          onChanged();
+        } else {
+          currentSessionBuilder_.setMessage(builderForValue.build());
+        }
+        bitField0_ |= 0x00000001;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+       */
+      public Builder mergeCurrentSession(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure value) {
+        if (currentSessionBuilder_ == null) {
+          if (((bitField0_ & 0x00000001) == 0x00000001) &&
+              currentSession_ != org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.getDefaultInstance()) {
+            currentSession_ =
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.newBuilder(currentSession_).mergeFrom(value).buildPartial();
+          } else {
+            currentSession_ = value;
+          }
+          onChanged();
+        } else {
+          currentSessionBuilder_.mergeFrom(value);
+        }
+        bitField0_ |= 0x00000001;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+       */
+      public Builder clearCurrentSession() {
+        if (currentSessionBuilder_ == null) {
+          currentSession_ = org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.getDefaultInstance();
+          onChanged();
+        } else {
+          currentSessionBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000001);
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder getCurrentSessionBuilder() {
+        bitField0_ |= 0x00000001;
+        onChanged();
+        return getCurrentSessionFieldBuilder().getBuilder();
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder getCurrentSessionOrBuilder() {
+        if (currentSessionBuilder_ != null) {
+          return currentSessionBuilder_.getMessageOrBuilder();
+        } else {
+          return currentSession_;
+        }
+      }
+      /**
+       * <code>optional .textsecure.SessionStructure currentSession = 1;</code>
+       */
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder> 
+          getCurrentSessionFieldBuilder() {
+        if (currentSessionBuilder_ == null) {
+          currentSessionBuilder_ = new com.google.protobuf.SingleFieldBuilder<
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder>(
+                  currentSession_,
+                  getParentForChildren(),
+                  isClean());
+          currentSession_ = null;
+        }
+        return currentSessionBuilder_;
+      }
+
+      // repeated .textsecure.SessionStructure previousSessions = 2;
+      private java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure> previousSessions_ =
+        java.util.Collections.emptyList();
+      private void ensurePreviousSessionsIsMutable() {
+        if (!((bitField0_ & 0x00000002) == 0x00000002)) {
+          previousSessions_ = new java.util.ArrayList<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure>(previousSessions_);
+          bitField0_ |= 0x00000002;
+         }
+      }
+
+      private com.google.protobuf.RepeatedFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder> previousSessionsBuilder_;
+
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure> getPreviousSessionsList() {
+        if (previousSessionsBuilder_ == null) {
+          return java.util.Collections.unmodifiableList(previousSessions_);
+        } else {
+          return previousSessionsBuilder_.getMessageList();
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public int getPreviousSessionsCount() {
+        if (previousSessionsBuilder_ == null) {
+          return previousSessions_.size();
+        } else {
+          return previousSessionsBuilder_.getCount();
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure getPreviousSessions(int index) {
+        if (previousSessionsBuilder_ == null) {
+          return previousSessions_.get(index);
+        } else {
+          return previousSessionsBuilder_.getMessage(index);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public Builder setPreviousSessions(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure value) {
+        if (previousSessionsBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensurePreviousSessionsIsMutable();
+          previousSessions_.set(index, value);
+          onChanged();
+        } else {
+          previousSessionsBuilder_.setMessage(index, value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public Builder setPreviousSessions(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder builderForValue) {
+        if (previousSessionsBuilder_ == null) {
+          ensurePreviousSessionsIsMutable();
+          previousSessions_.set(index, builderForValue.build());
+          onChanged();
+        } else {
+          previousSessionsBuilder_.setMessage(index, builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public Builder addPreviousSessions(org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure value) {
+        if (previousSessionsBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensurePreviousSessionsIsMutable();
+          previousSessions_.add(value);
+          onChanged();
+        } else {
+          previousSessionsBuilder_.addMessage(value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public Builder addPreviousSessions(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure value) {
+        if (previousSessionsBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensurePreviousSessionsIsMutable();
+          previousSessions_.add(index, value);
+          onChanged();
+        } else {
+          previousSessionsBuilder_.addMessage(index, value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public Builder addPreviousSessions(
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder builderForValue) {
+        if (previousSessionsBuilder_ == null) {
+          ensurePreviousSessionsIsMutable();
+          previousSessions_.add(builderForValue.build());
+          onChanged();
+        } else {
+          previousSessionsBuilder_.addMessage(builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public Builder addPreviousSessions(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder builderForValue) {
+        if (previousSessionsBuilder_ == null) {
+          ensurePreviousSessionsIsMutable();
+          previousSessions_.add(index, builderForValue.build());
+          onChanged();
+        } else {
+          previousSessionsBuilder_.addMessage(index, builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public Builder addAllPreviousSessions(
+          java.lang.Iterable<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure> values) {
+        if (previousSessionsBuilder_ == null) {
+          ensurePreviousSessionsIsMutable();
+          super.addAll(values, previousSessions_);
+          onChanged();
+        } else {
+          previousSessionsBuilder_.addAllMessages(values);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public Builder clearPreviousSessions() {
+        if (previousSessionsBuilder_ == null) {
+          previousSessions_ = java.util.Collections.emptyList();
+          bitField0_ = (bitField0_ & ~0x00000002);
+          onChanged();
+        } else {
+          previousSessionsBuilder_.clear();
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public Builder removePreviousSessions(int index) {
+        if (previousSessionsBuilder_ == null) {
+          ensurePreviousSessionsIsMutable();
+          previousSessions_.remove(index);
+          onChanged();
+        } else {
+          previousSessionsBuilder_.remove(index);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder getPreviousSessionsBuilder(
+          int index) {
+        return getPreviousSessionsFieldBuilder().getBuilder(index);
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder getPreviousSessionsOrBuilder(
+          int index) {
+        if (previousSessionsBuilder_ == null) {
+          return previousSessions_.get(index);  } else {
+          return previousSessionsBuilder_.getMessageOrBuilder(index);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder> 
+           getPreviousSessionsOrBuilderList() {
+        if (previousSessionsBuilder_ != null) {
+          return previousSessionsBuilder_.getMessageOrBuilderList();
+        } else {
+          return java.util.Collections.unmodifiableList(previousSessions_);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder addPreviousSessionsBuilder() {
+        return getPreviousSessionsFieldBuilder().addBuilder(
+            org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.getDefaultInstance());
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder addPreviousSessionsBuilder(
+          int index) {
+        return getPreviousSessionsFieldBuilder().addBuilder(
+            index, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.getDefaultInstance());
+      }
+      /**
+       * <code>repeated .textsecure.SessionStructure previousSessions = 2;</code>
+       */
+      public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder> 
+           getPreviousSessionsBuilderList() {
+        return getPreviousSessionsFieldBuilder().getBuilderList();
+      }
+      private com.google.protobuf.RepeatedFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder> 
+          getPreviousSessionsFieldBuilder() {
+        if (previousSessionsBuilder_ == null) {
+          previousSessionsBuilder_ = new com.google.protobuf.RepeatedFieldBuilder<
+              org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructure.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SessionStructureOrBuilder>(
+                  previousSessions_,
+                  ((bitField0_ & 0x00000002) == 0x00000002),
+                  getParentForChildren(),
+                  isClean());
+          previousSessions_ = null;
+        }
+        return previousSessionsBuilder_;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.RecordStructure)
+    }
+
+    static {
+      defaultInstance = new RecordStructure(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.RecordStructure)
+  }
+
+  public interface PreKeyRecordStructureOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional uint32 id = 1;
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    boolean hasId();
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    int getId();
+
+    // optional bytes publicKey = 2;
+    /**
+     * <code>optional bytes publicKey = 2;</code>
+     */
+    boolean hasPublicKey();
+    /**
+     * <code>optional bytes publicKey = 2;</code>
+     */
+    com.google.protobuf.ByteString getPublicKey();
+
+    // optional bytes privateKey = 3;
+    /**
+     * <code>optional bytes privateKey = 3;</code>
+     */
+    boolean hasPrivateKey();
+    /**
+     * <code>optional bytes privateKey = 3;</code>
+     */
+    com.google.protobuf.ByteString getPrivateKey();
+  }
+  /**
+   * Protobuf type {@code textsecure.PreKeyRecordStructure}
+   */
+  public static final class PreKeyRecordStructure extends
+      com.google.protobuf.GeneratedMessage
+      implements PreKeyRecordStructureOrBuilder {
+    // Use PreKeyRecordStructure.newBuilder() to construct.
+    private PreKeyRecordStructure(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private PreKeyRecordStructure(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final PreKeyRecordStructure defaultInstance;
+    public static PreKeyRecordStructure getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public PreKeyRecordStructure getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private PreKeyRecordStructure(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 8: {
+              bitField0_ |= 0x00000001;
+              id_ = input.readUInt32();
+              break;
+            }
+            case 18: {
+              bitField0_ |= 0x00000002;
+              publicKey_ = input.readBytes();
+              break;
+            }
+            case 26: {
+              bitField0_ |= 0x00000004;
+              privateKey_ = input.readBytes();
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_PreKeyRecordStructure_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_PreKeyRecordStructure_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<PreKeyRecordStructure> PARSER =
+        new com.google.protobuf.AbstractParser<PreKeyRecordStructure>() {
+      public PreKeyRecordStructure parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new PreKeyRecordStructure(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<PreKeyRecordStructure> getParserForType() {
+      return PARSER;
+    }
+
+    private int bitField0_;
+    // optional uint32 id = 1;
+    public static final int ID_FIELD_NUMBER = 1;
+    private int id_;
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    public boolean hasId() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    public int getId() {
+      return id_;
+    }
+
+    // optional bytes publicKey = 2;
+    public static final int PUBLICKEY_FIELD_NUMBER = 2;
+    private com.google.protobuf.ByteString publicKey_;
+    /**
+     * <code>optional bytes publicKey = 2;</code>
+     */
+    public boolean hasPublicKey() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>optional bytes publicKey = 2;</code>
+     */
+    public com.google.protobuf.ByteString getPublicKey() {
+      return publicKey_;
+    }
+
+    // optional bytes privateKey = 3;
+    public static final int PRIVATEKEY_FIELD_NUMBER = 3;
+    private com.google.protobuf.ByteString privateKey_;
+    /**
+     * <code>optional bytes privateKey = 3;</code>
+     */
+    public boolean hasPrivateKey() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>optional bytes privateKey = 3;</code>
+     */
+    public com.google.protobuf.ByteString getPrivateKey() {
+      return privateKey_;
+    }
+
+    private void initFields() {
+      id_ = 0;
+      publicKey_ = com.google.protobuf.ByteString.EMPTY;
+      privateKey_ = com.google.protobuf.ByteString.EMPTY;
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeUInt32(1, id_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeBytes(2, publicKey_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeBytes(3, privateKey_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(1, id_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(2, publicKey_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(3, privateKey_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.PreKeyRecordStructure}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructureOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_PreKeyRecordStructure_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_PreKeyRecordStructure_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        id_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        publicKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000002);
+        privateKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000004);
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_PreKeyRecordStructure_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure build() {
+        org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure buildPartial() {
+        org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure result = new org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.id_ = id_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        result.publicKey_ = publicKey_;
+        if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        result.privateKey_ = privateKey_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure) {
+          return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure other) {
+        if (other == org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure.getDefaultInstance()) return this;
+        if (other.hasId()) {
+          setId(other.getId());
+        }
+        if (other.hasPublicKey()) {
+          setPublicKey(other.getPublicKey());
+        }
+        if (other.hasPrivateKey()) {
+          setPrivateKey(other.getPrivateKey());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.PreKeyRecordStructure) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional uint32 id = 1;
+      private int id_ ;
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public boolean hasId() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public int getId() {
+        return id_;
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public Builder setId(int value) {
+        bitField0_ |= 0x00000001;
+        id_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public Builder clearId() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        id_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional bytes publicKey = 2;
+      private com.google.protobuf.ByteString publicKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes publicKey = 2;</code>
+       */
+      public boolean hasPublicKey() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional bytes publicKey = 2;</code>
+       */
+      public com.google.protobuf.ByteString getPublicKey() {
+        return publicKey_;
+      }
+      /**
+       * <code>optional bytes publicKey = 2;</code>
+       */
+      public Builder setPublicKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+        publicKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes publicKey = 2;</code>
+       */
+      public Builder clearPublicKey() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        publicKey_ = getDefaultInstance().getPublicKey();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes privateKey = 3;
+      private com.google.protobuf.ByteString privateKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes privateKey = 3;</code>
+       */
+      public boolean hasPrivateKey() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional bytes privateKey = 3;</code>
+       */
+      public com.google.protobuf.ByteString getPrivateKey() {
+        return privateKey_;
+      }
+      /**
+       * <code>optional bytes privateKey = 3;</code>
+       */
+      public Builder setPrivateKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000004;
+        privateKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes privateKey = 3;</code>
+       */
+      public Builder clearPrivateKey() {
+        bitField0_ = (bitField0_ & ~0x00000004);
+        privateKey_ = getDefaultInstance().getPrivateKey();
+        onChanged();
+        return this;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.PreKeyRecordStructure)
+    }
+
+    static {
+      defaultInstance = new PreKeyRecordStructure(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.PreKeyRecordStructure)
+  }
+
+  public interface SignedPreKeyRecordStructureOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional uint32 id = 1;
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    boolean hasId();
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    int getId();
+
+    // optional bytes publicKey = 2;
+    /**
+     * <code>optional bytes publicKey = 2;</code>
+     */
+    boolean hasPublicKey();
+    /**
+     * <code>optional bytes publicKey = 2;</code>
+     */
+    com.google.protobuf.ByteString getPublicKey();
+
+    // optional bytes privateKey = 3;
+    /**
+     * <code>optional bytes privateKey = 3;</code>
+     */
+    boolean hasPrivateKey();
+    /**
+     * <code>optional bytes privateKey = 3;</code>
+     */
+    com.google.protobuf.ByteString getPrivateKey();
+
+    // optional bytes signature = 4;
+    /**
+     * <code>optional bytes signature = 4;</code>
+     */
+    boolean hasSignature();
+    /**
+     * <code>optional bytes signature = 4;</code>
+     */
+    com.google.protobuf.ByteString getSignature();
+
+    // optional fixed64 timestamp = 5;
+    /**
+     * <code>optional fixed64 timestamp = 5;</code>
+     */
+    boolean hasTimestamp();
+    /**
+     * <code>optional fixed64 timestamp = 5;</code>
+     */
+    long getTimestamp();
+  }
+  /**
+   * Protobuf type {@code textsecure.SignedPreKeyRecordStructure}
+   */
+  public static final class SignedPreKeyRecordStructure extends
+      com.google.protobuf.GeneratedMessage
+      implements SignedPreKeyRecordStructureOrBuilder {
+    // Use SignedPreKeyRecordStructure.newBuilder() to construct.
+    private SignedPreKeyRecordStructure(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private SignedPreKeyRecordStructure(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final SignedPreKeyRecordStructure defaultInstance;
+    public static SignedPreKeyRecordStructure getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public SignedPreKeyRecordStructure getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private SignedPreKeyRecordStructure(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 8: {
+              bitField0_ |= 0x00000001;
+              id_ = input.readUInt32();
+              break;
+            }
+            case 18: {
+              bitField0_ |= 0x00000002;
+              publicKey_ = input.readBytes();
+              break;
+            }
+            case 26: {
+              bitField0_ |= 0x00000004;
+              privateKey_ = input.readBytes();
+              break;
+            }
+            case 34: {
+              bitField0_ |= 0x00000008;
+              signature_ = input.readBytes();
+              break;
+            }
+            case 41: {
+              bitField0_ |= 0x00000010;
+              timestamp_ = input.readFixed64();
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SignedPreKeyRecordStructure_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SignedPreKeyRecordStructure_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<SignedPreKeyRecordStructure> PARSER =
+        new com.google.protobuf.AbstractParser<SignedPreKeyRecordStructure>() {
+      public SignedPreKeyRecordStructure parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new SignedPreKeyRecordStructure(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<SignedPreKeyRecordStructure> getParserForType() {
+      return PARSER;
+    }
+
+    private int bitField0_;
+    // optional uint32 id = 1;
+    public static final int ID_FIELD_NUMBER = 1;
+    private int id_;
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    public boolean hasId() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional uint32 id = 1;</code>
+     */
+    public int getId() {
+      return id_;
+    }
+
+    // optional bytes publicKey = 2;
+    public static final int PUBLICKEY_FIELD_NUMBER = 2;
+    private com.google.protobuf.ByteString publicKey_;
+    /**
+     * <code>optional bytes publicKey = 2;</code>
+     */
+    public boolean hasPublicKey() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>optional bytes publicKey = 2;</code>
+     */
+    public com.google.protobuf.ByteString getPublicKey() {
+      return publicKey_;
+    }
+
+    // optional bytes privateKey = 3;
+    public static final int PRIVATEKEY_FIELD_NUMBER = 3;
+    private com.google.protobuf.ByteString privateKey_;
+    /**
+     * <code>optional bytes privateKey = 3;</code>
+     */
+    public boolean hasPrivateKey() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>optional bytes privateKey = 3;</code>
+     */
+    public com.google.protobuf.ByteString getPrivateKey() {
+      return privateKey_;
+    }
+
+    // optional bytes signature = 4;
+    public static final int SIGNATURE_FIELD_NUMBER = 4;
+    private com.google.protobuf.ByteString signature_;
+    /**
+     * <code>optional bytes signature = 4;</code>
+     */
+    public boolean hasSignature() {
+      return ((bitField0_ & 0x00000008) == 0x00000008);
+    }
+    /**
+     * <code>optional bytes signature = 4;</code>
+     */
+    public com.google.protobuf.ByteString getSignature() {
+      return signature_;
+    }
+
+    // optional fixed64 timestamp = 5;
+    public static final int TIMESTAMP_FIELD_NUMBER = 5;
+    private long timestamp_;
+    /**
+     * <code>optional fixed64 timestamp = 5;</code>
+     */
+    public boolean hasTimestamp() {
+      return ((bitField0_ & 0x00000010) == 0x00000010);
+    }
+    /**
+     * <code>optional fixed64 timestamp = 5;</code>
+     */
+    public long getTimestamp() {
+      return timestamp_;
+    }
+
+    private void initFields() {
+      id_ = 0;
+      publicKey_ = com.google.protobuf.ByteString.EMPTY;
+      privateKey_ = com.google.protobuf.ByteString.EMPTY;
+      signature_ = com.google.protobuf.ByteString.EMPTY;
+      timestamp_ = 0L;
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeUInt32(1, id_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeBytes(2, publicKey_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeBytes(3, privateKey_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        output.writeBytes(4, signature_);
+      }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        output.writeFixed64(5, timestamp_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(1, id_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(2, publicKey_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(3, privateKey_);
+      }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(4, signature_);
+      }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeFixed64Size(5, timestamp_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.SignedPreKeyRecordStructure}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructureOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SignedPreKeyRecordStructure_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SignedPreKeyRecordStructure_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        id_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        publicKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000002);
+        privateKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000004);
+        signature_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000008);
+        timestamp_ = 0L;
+        bitField0_ = (bitField0_ & ~0x00000010);
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SignedPreKeyRecordStructure_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure build() {
+        org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure buildPartial() {
+        org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure result = new org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.id_ = id_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        result.publicKey_ = publicKey_;
+        if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        result.privateKey_ = privateKey_;
+        if (((from_bitField0_ & 0x00000008) == 0x00000008)) {
+          to_bitField0_ |= 0x00000008;
+        }
+        result.signature_ = signature_;
+        if (((from_bitField0_ & 0x00000010) == 0x00000010)) {
+          to_bitField0_ |= 0x00000010;
+        }
+        result.timestamp_ = timestamp_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure) {
+          return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure other) {
+        if (other == org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure.getDefaultInstance()) return this;
+        if (other.hasId()) {
+          setId(other.getId());
+        }
+        if (other.hasPublicKey()) {
+          setPublicKey(other.getPublicKey());
+        }
+        if (other.hasPrivateKey()) {
+          setPrivateKey(other.getPrivateKey());
+        }
+        if (other.hasSignature()) {
+          setSignature(other.getSignature());
+        }
+        if (other.hasTimestamp()) {
+          setTimestamp(other.getTimestamp());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SignedPreKeyRecordStructure) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional uint32 id = 1;
+      private int id_ ;
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public boolean hasId() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public int getId() {
+        return id_;
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public Builder setId(int value) {
+        bitField0_ |= 0x00000001;
+        id_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 id = 1;</code>
+       */
+      public Builder clearId() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        id_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional bytes publicKey = 2;
+      private com.google.protobuf.ByteString publicKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes publicKey = 2;</code>
+       */
+      public boolean hasPublicKey() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional bytes publicKey = 2;</code>
+       */
+      public com.google.protobuf.ByteString getPublicKey() {
+        return publicKey_;
+      }
+      /**
+       * <code>optional bytes publicKey = 2;</code>
+       */
+      public Builder setPublicKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+        publicKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes publicKey = 2;</code>
+       */
+      public Builder clearPublicKey() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        publicKey_ = getDefaultInstance().getPublicKey();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes privateKey = 3;
+      private com.google.protobuf.ByteString privateKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes privateKey = 3;</code>
+       */
+      public boolean hasPrivateKey() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional bytes privateKey = 3;</code>
+       */
+      public com.google.protobuf.ByteString getPrivateKey() {
+        return privateKey_;
+      }
+      /**
+       * <code>optional bytes privateKey = 3;</code>
+       */
+      public Builder setPrivateKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000004;
+        privateKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes privateKey = 3;</code>
+       */
+      public Builder clearPrivateKey() {
+        bitField0_ = (bitField0_ & ~0x00000004);
+        privateKey_ = getDefaultInstance().getPrivateKey();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes signature = 4;
+      private com.google.protobuf.ByteString signature_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes signature = 4;</code>
+       */
+      public boolean hasSignature() {
+        return ((bitField0_ & 0x00000008) == 0x00000008);
+      }
+      /**
+       * <code>optional bytes signature = 4;</code>
+       */
+      public com.google.protobuf.ByteString getSignature() {
+        return signature_;
+      }
+      /**
+       * <code>optional bytes signature = 4;</code>
+       */
+      public Builder setSignature(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000008;
+        signature_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes signature = 4;</code>
+       */
+      public Builder clearSignature() {
+        bitField0_ = (bitField0_ & ~0x00000008);
+        signature_ = getDefaultInstance().getSignature();
+        onChanged();
+        return this;
+      }
+
+      // optional fixed64 timestamp = 5;
+      private long timestamp_ ;
+      /**
+       * <code>optional fixed64 timestamp = 5;</code>
+       */
+      public boolean hasTimestamp() {
+        return ((bitField0_ & 0x00000010) == 0x00000010);
+      }
+      /**
+       * <code>optional fixed64 timestamp = 5;</code>
+       */
+      public long getTimestamp() {
+        return timestamp_;
+      }
+      /**
+       * <code>optional fixed64 timestamp = 5;</code>
+       */
+      public Builder setTimestamp(long value) {
+        bitField0_ |= 0x00000010;
+        timestamp_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional fixed64 timestamp = 5;</code>
+       */
+      public Builder clearTimestamp() {
+        bitField0_ = (bitField0_ & ~0x00000010);
+        timestamp_ = 0L;
+        onChanged();
+        return this;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.SignedPreKeyRecordStructure)
+    }
+
+    static {
+      defaultInstance = new SignedPreKeyRecordStructure(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.SignedPreKeyRecordStructure)
+  }
+
+  public interface IdentityKeyPairStructureOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional bytes publicKey = 1;
+    /**
+     * <code>optional bytes publicKey = 1;</code>
+     */
+    boolean hasPublicKey();
+    /**
+     * <code>optional bytes publicKey = 1;</code>
+     */
+    com.google.protobuf.ByteString getPublicKey();
+
+    // optional bytes privateKey = 2;
+    /**
+     * <code>optional bytes privateKey = 2;</code>
+     */
+    boolean hasPrivateKey();
+    /**
+     * <code>optional bytes privateKey = 2;</code>
+     */
+    com.google.protobuf.ByteString getPrivateKey();
+  }
+  /**
+   * Protobuf type {@code textsecure.IdentityKeyPairStructure}
+   */
+  public static final class IdentityKeyPairStructure extends
+      com.google.protobuf.GeneratedMessage
+      implements IdentityKeyPairStructureOrBuilder {
+    // Use IdentityKeyPairStructure.newBuilder() to construct.
+    private IdentityKeyPairStructure(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private IdentityKeyPairStructure(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final IdentityKeyPairStructure defaultInstance;
+    public static IdentityKeyPairStructure getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public IdentityKeyPairStructure getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private IdentityKeyPairStructure(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 10: {
+              bitField0_ |= 0x00000001;
+              publicKey_ = input.readBytes();
+              break;
+            }
+            case 18: {
+              bitField0_ |= 0x00000002;
+              privateKey_ = input.readBytes();
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_IdentityKeyPairStructure_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_IdentityKeyPairStructure_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<IdentityKeyPairStructure> PARSER =
+        new com.google.protobuf.AbstractParser<IdentityKeyPairStructure>() {
+      public IdentityKeyPairStructure parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new IdentityKeyPairStructure(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<IdentityKeyPairStructure> getParserForType() {
+      return PARSER;
+    }
+
+    private int bitField0_;
+    // optional bytes publicKey = 1;
+    public static final int PUBLICKEY_FIELD_NUMBER = 1;
+    private com.google.protobuf.ByteString publicKey_;
+    /**
+     * <code>optional bytes publicKey = 1;</code>
+     */
+    public boolean hasPublicKey() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional bytes publicKey = 1;</code>
+     */
+    public com.google.protobuf.ByteString getPublicKey() {
+      return publicKey_;
+    }
+
+    // optional bytes privateKey = 2;
+    public static final int PRIVATEKEY_FIELD_NUMBER = 2;
+    private com.google.protobuf.ByteString privateKey_;
+    /**
+     * <code>optional bytes privateKey = 2;</code>
+     */
+    public boolean hasPrivateKey() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>optional bytes privateKey = 2;</code>
+     */
+    public com.google.protobuf.ByteString getPrivateKey() {
+      return privateKey_;
+    }
+
+    private void initFields() {
+      publicKey_ = com.google.protobuf.ByteString.EMPTY;
+      privateKey_ = com.google.protobuf.ByteString.EMPTY;
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeBytes(1, publicKey_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeBytes(2, privateKey_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(1, publicKey_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(2, privateKey_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.IdentityKeyPairStructure}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructureOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_IdentityKeyPairStructure_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_IdentityKeyPairStructure_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        publicKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        privateKey_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000002);
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_IdentityKeyPairStructure_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure build() {
+        org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure buildPartial() {
+        org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure result = new org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.publicKey_ = publicKey_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        result.privateKey_ = privateKey_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure) {
+          return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure other) {
+        if (other == org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure.getDefaultInstance()) return this;
+        if (other.hasPublicKey()) {
+          setPublicKey(other.getPublicKey());
+        }
+        if (other.hasPrivateKey()) {
+          setPrivateKey(other.getPrivateKey());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional bytes publicKey = 1;
+      private com.google.protobuf.ByteString publicKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes publicKey = 1;</code>
+       */
+      public boolean hasPublicKey() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional bytes publicKey = 1;</code>
+       */
+      public com.google.protobuf.ByteString getPublicKey() {
+        return publicKey_;
+      }
+      /**
+       * <code>optional bytes publicKey = 1;</code>
+       */
+      public Builder setPublicKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000001;
+        publicKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes publicKey = 1;</code>
+       */
+      public Builder clearPublicKey() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        publicKey_ = getDefaultInstance().getPublicKey();
+        onChanged();
+        return this;
+      }
+
+      // optional bytes privateKey = 2;
+      private com.google.protobuf.ByteString privateKey_ = com.google.protobuf.ByteString.EMPTY;
+      /**
+       * <code>optional bytes privateKey = 2;</code>
+       */
+      public boolean hasPrivateKey() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional bytes privateKey = 2;</code>
+       */
+      public com.google.protobuf.ByteString getPrivateKey() {
+        return privateKey_;
+      }
+      /**
+       * <code>optional bytes privateKey = 2;</code>
+       */
+      public Builder setPrivateKey(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+        privateKey_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bytes privateKey = 2;</code>
+       */
+      public Builder clearPrivateKey() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        privateKey_ = getDefaultInstance().getPrivateKey();
+        onChanged();
+        return this;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.IdentityKeyPairStructure)
+    }
+
+    static {
+      defaultInstance = new IdentityKeyPairStructure(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.IdentityKeyPairStructure)
+  }
+
+  public interface SenderKeyStateStructureOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional uint32 senderKeyId = 1;
+    /**
+     * <code>optional uint32 senderKeyId = 1;</code>
+     */
+    boolean hasSenderKeyId();
+    /**
+     * <code>optional uint32 senderKeyId = 1;</code>
+     */
+    int getSenderKeyId();
+
+    // optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+     */
+    boolean hasSenderChainKey();
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey getSenderChainKey();
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKeyOrBuilder getSenderChainKeyOrBuilder();
+
+    // optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+     */
+    boolean hasSenderSigningKey();
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey getSenderSigningKey();
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKeyOrBuilder getSenderSigningKeyOrBuilder();
+
+    // repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+     */
+    java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey> 
+        getSenderMessageKeysList();
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey getSenderMessageKeys(int index);
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+     */
+    int getSenderMessageKeysCount();
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+     */
+    java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKeyOrBuilder> 
+        getSenderMessageKeysOrBuilderList();
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKeyOrBuilder getSenderMessageKeysOrBuilder(
+        int index);
+  }
+  /**
+   * Protobuf type {@code textsecure.SenderKeyStateStructure}
+   */
+  public static final class SenderKeyStateStructure extends
+      com.google.protobuf.GeneratedMessage
+      implements SenderKeyStateStructureOrBuilder {
+    // Use SenderKeyStateStructure.newBuilder() to construct.
+    private SenderKeyStateStructure(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private SenderKeyStateStructure(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final SenderKeyStateStructure defaultInstance;
+    public static SenderKeyStateStructure getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public SenderKeyStateStructure getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private SenderKeyStateStructure(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 8: {
+              bitField0_ |= 0x00000001;
+              senderKeyId_ = input.readUInt32();
+              break;
+            }
+            case 18: {
+              org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.Builder subBuilder = null;
+              if (((bitField0_ & 0x00000002) == 0x00000002)) {
+                subBuilder = senderChainKey_.toBuilder();
+              }
+              senderChainKey_ = input.readMessage(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.PARSER, extensionRegistry);
+              if (subBuilder != null) {
+                subBuilder.mergeFrom(senderChainKey_);
+                senderChainKey_ = subBuilder.buildPartial();
+              }
+              bitField0_ |= 0x00000002;
+              break;
+            }
+            case 26: {
+              org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.Builder subBuilder = null;
+              if (((bitField0_ & 0x00000004) == 0x00000004)) {
+                subBuilder = senderSigningKey_.toBuilder();
+              }
+              senderSigningKey_ = input.readMessage(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.PARSER, extensionRegistry);
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+      /**
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+
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+      /**
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+      com.google.protobuf.ByteString getSeed();
+    }
+    /**
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+    public static final class SenderChainKey extends
+        com.google.protobuf.GeneratedMessage
+        implements SenderChainKeyOrBuilder {
+      // Use SenderChainKey.newBuilder() to construct.
+      private SenderChainKey(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+        super(builder);
+        this.unknownFields = builder.getUnknownFields();
+      }
+      private SenderChainKey(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+      private static final SenderChainKey defaultInstance;
+      public static SenderChainKey getDefaultInstance() {
+        return defaultInstance;
+      }
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+      public SenderChainKey getDefaultInstanceForType() {
+        return defaultInstance;
+      }
+
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+      @java.lang.Override
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+          getUnknownFields() {
+        return this.unknownFields;
+      }
+      private SenderChainKey(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        initFields();
+        int mutable_bitField0_ = 0;
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+          makeExtensionsImmutable();
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+      }
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyStateStructure_SenderChainKey_descriptor;
+      }
+
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+          internalGetFieldAccessorTable() {
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+                org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.class, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.Builder.class);
+      }
+
+      public static com.google.protobuf.Parser<SenderChainKey> PARSER =
+          new com.google.protobuf.AbstractParser<SenderChainKey>() {
+        public SenderChainKey parsePartialFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return new SenderChainKey(input, extensionRegistry);
+        }
+      };
+
+      @java.lang.Override
+      public com.google.protobuf.Parser<SenderChainKey> getParserForType() {
+        return PARSER;
+      }
+
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+      }
+
+      // optional bytes seed = 2;
+      public static final int SEED_FIELD_NUMBER = 2;
+      private com.google.protobuf.ByteString seed_;
+      /**
+       * <code>optional bytes seed = 2;</code>
+       */
+      public boolean hasSeed() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
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+      /**
+       * <code>optional bytes seed = 2;</code>
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+      @java.lang.Override
+      protected java.lang.Object writeReplace()
+          throws java.io.ObjectStreamException {
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+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey parseFrom(
+          com.google.protobuf.ByteString data)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey parseFrom(
+          com.google.protobuf.ByteString data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey parseFrom(byte[] data)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey parseFrom(
+          byte[] data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey parseFrom(java.io.InputStream input)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey parseFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey parseDelimitedFrom(java.io.InputStream input)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey parseDelimitedFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey parseFrom(
+          com.google.protobuf.CodedInputStream input)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey parseFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
+      }
+
+      public static Builder newBuilder() { return Builder.create(); }
+      public Builder newBuilderForType() { return newBuilder(); }
+      public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey prototype) {
+        return newBuilder().mergeFrom(prototype);
+      }
+      public Builder toBuilder() { return newBuilder(this); }
+
+      @java.lang.Override
+      protected Builder newBuilderForType(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        Builder builder = new Builder(parent);
+        return builder;
+      }
+      /**
+       * Protobuf type {@code textsecure.SenderKeyStateStructure.SenderChainKey}
+       */
+      public static final class Builder extends
+          com.google.protobuf.GeneratedMessage.Builder<Builder>
+         implements org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKeyOrBuilder {
+        public static final com.google.protobuf.Descriptors.Descriptor
+            getDescriptor() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyStateStructure_SenderChainKey_descriptor;
+        }
+
+        protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+            internalGetFieldAccessorTable() {
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+                  org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.class, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.Builder.class);
+        }
+
+        // Construct using org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.newBuilder()
+        private Builder() {
+          maybeForceBuilderInitialization();
+        }
+
+        private Builder(
+            com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+          super(parent);
+          maybeForceBuilderInitialization();
+        }
+        private void maybeForceBuilderInitialization() {
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+        public Builder clear() {
+          super.clear();
+          iteration_ = 0;
+          bitField0_ = (bitField0_ & ~0x00000001);
+          seed_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000002);
+          return this;
+        }
+
+        public Builder clone() {
+          return create().mergeFrom(buildPartial());
+        }
+
+        public com.google.protobuf.Descriptors.Descriptor
+            getDescriptorForType() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyStateStructure_SenderChainKey_descriptor;
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey getDefaultInstanceForType() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.getDefaultInstance();
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey build() {
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+          if (!result.isInitialized()) {
+            throw newUninitializedMessageException(result);
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+          return result;
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey buildPartial() {
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey result = new org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey(this);
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+          onBuilt();
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+
+        public Builder mergeFrom(com.google.protobuf.Message other) {
+          if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey) {
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+          } else {
+            super.mergeFrom(other);
+            return this;
+          }
+        }
+
+        public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey other) {
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+          return this;
+        }
+
+        public final boolean isInitialized() {
+          return true;
+        }
+
+        public Builder mergeFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey parsedMessage = null;
+          try {
+            parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey) e.getUnfinishedMessage();
+            throw e;
+          } finally {
+            if (parsedMessage != null) {
+              mergeFrom(parsedMessage);
+            }
+          }
+          return this;
+        }
+        private int bitField0_;
+
+        // optional uint32 iteration = 1;
+        private int iteration_ ;
+        /**
+         * <code>optional uint32 iteration = 1;</code>
+         */
+        public boolean hasIteration() {
+          return ((bitField0_ & 0x00000001) == 0x00000001);
+        }
+        /**
+         * <code>optional uint32 iteration = 1;</code>
+         */
+        public int getIteration() {
+          return iteration_;
+        }
+        /**
+         * <code>optional uint32 iteration = 1;</code>
+         */
+        public Builder setIteration(int value) {
+          bitField0_ |= 0x00000001;
+          iteration_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional uint32 iteration = 1;</code>
+         */
+        public Builder clearIteration() {
+          bitField0_ = (bitField0_ & ~0x00000001);
+          iteration_ = 0;
+          onChanged();
+          return this;
+        }
+
+        // optional bytes seed = 2;
+        private com.google.protobuf.ByteString seed_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes seed = 2;</code>
+         */
+        public boolean hasSeed() {
+          return ((bitField0_ & 0x00000002) == 0x00000002);
+        }
+        /**
+         * <code>optional bytes seed = 2;</code>
+         */
+        public com.google.protobuf.ByteString getSeed() {
+          return seed_;
+        }
+        /**
+         * <code>optional bytes seed = 2;</code>
+         */
+        public Builder setSeed(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
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+  bitField0_ |= 0x00000002;
+          seed_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes seed = 2;</code>
+         */
+        public Builder clearSeed() {
+          bitField0_ = (bitField0_ & ~0x00000002);
+          seed_ = getDefaultInstance().getSeed();
+          onChanged();
+          return this;
+        }
+
+        // @@protoc_insertion_point(builder_scope:textsecure.SenderKeyStateStructure.SenderChainKey)
+      }
+
+      static {
+        defaultInstance = new SenderChainKey(true);
+        defaultInstance.initFields();
+      }
+
+      // @@protoc_insertion_point(class_scope:textsecure.SenderKeyStateStructure.SenderChainKey)
+    }
+
+    public interface SenderMessageKeyOrBuilder
+        extends com.google.protobuf.MessageOrBuilder {
+
+      // optional uint32 iteration = 1;
+      /**
+       * <code>optional uint32 iteration = 1;</code>
+       */
+      boolean hasIteration();
+      /**
+       * <code>optional uint32 iteration = 1;</code>
+       */
+      int getIteration();
+
+      // optional bytes seed = 2;
+      /**
+       * <code>optional bytes seed = 2;</code>
+       */
+      boolean hasSeed();
+      /**
+       * <code>optional bytes seed = 2;</code>
+       */
+      com.google.protobuf.ByteString getSeed();
+    }
+    /**
+     * Protobuf type {@code textsecure.SenderKeyStateStructure.SenderMessageKey}
+     */
+    public static final class SenderMessageKey extends
+        com.google.protobuf.GeneratedMessage
+        implements SenderMessageKeyOrBuilder {
+      // Use SenderMessageKey.newBuilder() to construct.
+      private SenderMessageKey(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+        super(builder);
+        this.unknownFields = builder.getUnknownFields();
+      }
+      private SenderMessageKey(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+      private static final SenderMessageKey defaultInstance;
+      public static SenderMessageKey getDefaultInstance() {
+        return defaultInstance;
+      }
+
+      public SenderMessageKey getDefaultInstanceForType() {
+        return defaultInstance;
+      }
+
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+      @java.lang.Override
+      public final com.google.protobuf.UnknownFieldSet
+          getUnknownFields() {
+        return this.unknownFields;
+      }
+      private SenderMessageKey(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        initFields();
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+          throw new com.google.protobuf.InvalidProtocolBufferException(
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+          this.unknownFields = unknownFields.build();
+          makeExtensionsImmutable();
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+      }
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyStateStructure_SenderMessageKey_descriptor;
+      }
+
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+          internalGetFieldAccessorTable() {
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+      }
+
+      public static com.google.protobuf.Parser<SenderMessageKey> PARSER =
+          new com.google.protobuf.AbstractParser<SenderMessageKey>() {
+        public SenderMessageKey parsePartialFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return new SenderMessageKey(input, extensionRegistry);
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+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey parseFrom(
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+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
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+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey parseFrom(
+          com.google.protobuf.ByteString data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
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+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
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+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey parseFrom(
+          byte[] data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
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+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey parseFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey parseDelimitedFrom(java.io.InputStream input)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input);
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+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey parseDelimitedFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input, extensionRegistry);
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+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey parseFrom(
+          com.google.protobuf.CodedInputStream input)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
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+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey parseFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
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+      public static Builder newBuilder() { return Builder.create(); }
+      public Builder newBuilderForType() { return newBuilder(); }
+      public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey prototype) {
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+      }
+      public Builder toBuilder() { return newBuilder(this); }
+
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+      protected Builder newBuilderForType(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        Builder builder = new Builder(parent);
+        return builder;
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+      /**
+       * Protobuf type {@code textsecure.SenderKeyStateStructure.SenderMessageKey}
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+        }
+
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+        private Builder() {
+          maybeForceBuilderInitialization();
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+          seed_ = com.google.protobuf.ByteString.EMPTY;
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+
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+          return org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.getDefaultInstance();
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+        public Builder mergeFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey parsedMessage = null;
+          try {
+            parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey) e.getUnfinishedMessage();
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+
+        // optional uint32 iteration = 1;
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+        /**
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+          return ((bitField0_ & 0x00000001) == 0x00000001);
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+        /**
+         * <code>optional uint32 iteration = 1;</code>
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+        /**
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+          bitField0_ |= 0x00000001;
+          iteration_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional uint32 iteration = 1;</code>
+         */
+        public Builder clearIteration() {
+          bitField0_ = (bitField0_ & ~0x00000001);
+          iteration_ = 0;
+          onChanged();
+          return this;
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+
+        // optional bytes seed = 2;
+        private com.google.protobuf.ByteString seed_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes seed = 2;</code>
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+        public boolean hasSeed() {
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+        /**
+         * <code>optional bytes seed = 2;</code>
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+        public com.google.protobuf.ByteString getSeed() {
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+        /**
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+          if (value == null) {
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+  bitField0_ |= 0x00000002;
+          seed_ = value;
+          onChanged();
+          return this;
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+        /**
+         * <code>optional bytes seed = 2;</code>
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+          bitField0_ = (bitField0_ & ~0x00000002);
+          seed_ = getDefaultInstance().getSeed();
+          onChanged();
+          return this;
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+
+        // @@protoc_insertion_point(builder_scope:textsecure.SenderKeyStateStructure.SenderMessageKey)
+      }
+
+      static {
+        defaultInstance = new SenderMessageKey(true);
+        defaultInstance.initFields();
+      }
+
+      // @@protoc_insertion_point(class_scope:textsecure.SenderKeyStateStructure.SenderMessageKey)
+    }
+
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+        extends com.google.protobuf.MessageOrBuilder {
+
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+      /**
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+      // optional bytes private = 2;
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+      boolean hasPrivate();
+      /**
+       * <code>optional bytes private = 2;</code>
+       */
+      com.google.protobuf.ByteString getPrivate();
+    }
+    /**
+     * Protobuf type {@code textsecure.SenderKeyStateStructure.SenderSigningKey}
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+    public static final class SenderSigningKey extends
+        com.google.protobuf.GeneratedMessage
+        implements SenderSigningKeyOrBuilder {
+      // Use SenderSigningKey.newBuilder() to construct.
+      private SenderSigningKey(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+        super(builder);
+        this.unknownFields = builder.getUnknownFields();
+      }
+      private SenderSigningKey(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
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+      private static final SenderSigningKey defaultInstance;
+      public static SenderSigningKey getDefaultInstance() {
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+      }
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+      public final com.google.protobuf.UnknownFieldSet
+          getUnknownFields() {
+        return this.unknownFields;
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+      private SenderSigningKey(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        initFields();
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+          throw new com.google.protobuf.InvalidProtocolBufferException(
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+          makeExtensionsImmutable();
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+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyStateStructure_SenderSigningKey_descriptor;
+      }
+
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+          internalGetFieldAccessorTable() {
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+      }
+
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+          new com.google.protobuf.AbstractParser<SenderSigningKey>() {
+        public SenderSigningKey parsePartialFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+          return new SenderSigningKey(input, extensionRegistry);
+        }
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+
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+      public com.google.protobuf.Parser<SenderSigningKey> getParserForType() {
+        return PARSER;
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+      /**
+       * <code>optional bytes private = 2;</code>
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+      /**
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+      protected java.lang.Object writeReplace()
+          throws java.io.ObjectStreamException {
+        return super.writeReplace();
+      }
+
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey parseFrom(
+          com.google.protobuf.ByteString data)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey parseFrom(
+          com.google.protobuf.ByteString data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey parseFrom(byte[] data)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey parseFrom(
+          byte[] data,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return PARSER.parseFrom(data, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey parseFrom(java.io.InputStream input)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey parseFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey parseDelimitedFrom(java.io.InputStream input)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey parseDelimitedFrom(
+          java.io.InputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseDelimitedFrom(input, extensionRegistry);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey parseFrom(
+          com.google.protobuf.CodedInputStream input)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input);
+      }
+      public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey parseFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        return PARSER.parseFrom(input, extensionRegistry);
+      }
+
+      public static Builder newBuilder() { return Builder.create(); }
+      public Builder newBuilderForType() { return newBuilder(); }
+      public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey prototype) {
+        return newBuilder().mergeFrom(prototype);
+      }
+      public Builder toBuilder() { return newBuilder(this); }
+
+      @java.lang.Override
+      protected Builder newBuilderForType(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        Builder builder = new Builder(parent);
+        return builder;
+      }
+      /**
+       * Protobuf type {@code textsecure.SenderKeyStateStructure.SenderSigningKey}
+       */
+      public static final class Builder extends
+          com.google.protobuf.GeneratedMessage.Builder<Builder>
+         implements org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKeyOrBuilder {
+        public static final com.google.protobuf.Descriptors.Descriptor
+            getDescriptor() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyStateStructure_SenderSigningKey_descriptor;
+        }
+
+        protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+            internalGetFieldAccessorTable() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyStateStructure_SenderSigningKey_fieldAccessorTable
+              .ensureFieldAccessorsInitialized(
+                  org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.class, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.Builder.class);
+        }
+
+        // Construct using org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.newBuilder()
+        private Builder() {
+          maybeForceBuilderInitialization();
+        }
+
+        private Builder(
+            com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+          super(parent);
+          maybeForceBuilderInitialization();
+        }
+        private void maybeForceBuilderInitialization() {
+          if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+          }
+        }
+        private static Builder create() {
+          return new Builder();
+        }
+
+        public Builder clear() {
+          super.clear();
+          public_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000001);
+          private_ = com.google.protobuf.ByteString.EMPTY;
+          bitField0_ = (bitField0_ & ~0x00000002);
+          return this;
+        }
+
+        public Builder clone() {
+          return create().mergeFrom(buildPartial());
+        }
+
+        public com.google.protobuf.Descriptors.Descriptor
+            getDescriptorForType() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyStateStructure_SenderSigningKey_descriptor;
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey getDefaultInstanceForType() {
+          return org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.getDefaultInstance();
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey build() {
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey result = buildPartial();
+          if (!result.isInitialized()) {
+            throw newUninitializedMessageException(result);
+          }
+          return result;
+        }
+
+        public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey buildPartial() {
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey result = new org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey(this);
+          int from_bitField0_ = bitField0_;
+          int to_bitField0_ = 0;
+          if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+            to_bitField0_ |= 0x00000001;
+          }
+          result.public_ = public_;
+          if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+            to_bitField0_ |= 0x00000002;
+          }
+          result.private_ = private_;
+          result.bitField0_ = to_bitField0_;
+          onBuilt();
+          return result;
+        }
+
+        public Builder mergeFrom(com.google.protobuf.Message other) {
+          if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey) {
+            return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey)other);
+          } else {
+            super.mergeFrom(other);
+            return this;
+          }
+        }
+
+        public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey other) {
+          if (other == org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.getDefaultInstance()) return this;
+          if (other.hasPublic()) {
+            setPublic(other.getPublic());
+          }
+          if (other.hasPrivate()) {
+            setPrivate(other.getPrivate());
+          }
+          this.mergeUnknownFields(other.getUnknownFields());
+          return this;
+        }
+
+        public final boolean isInitialized() {
+          return true;
+        }
+
+        public Builder mergeFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey parsedMessage = null;
+          try {
+            parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey) e.getUnfinishedMessage();
+            throw e;
+          } finally {
+            if (parsedMessage != null) {
+              mergeFrom(parsedMessage);
+            }
+          }
+          return this;
+        }
+        private int bitField0_;
+
+        // optional bytes public = 1;
+        private com.google.protobuf.ByteString public_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes public = 1;</code>
+         */
+        public boolean hasPublic() {
+          return ((bitField0_ & 0x00000001) == 0x00000001);
+        }
+        /**
+         * <code>optional bytes public = 1;</code>
+         */
+        public com.google.protobuf.ByteString getPublic() {
+          return public_;
+        }
+        /**
+         * <code>optional bytes public = 1;</code>
+         */
+        public Builder setPublic(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000001;
+          public_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes public = 1;</code>
+         */
+        public Builder clearPublic() {
+          bitField0_ = (bitField0_ & ~0x00000001);
+          public_ = getDefaultInstance().getPublic();
+          onChanged();
+          return this;
+        }
+
+        // optional bytes private = 2;
+        private com.google.protobuf.ByteString private_ = com.google.protobuf.ByteString.EMPTY;
+        /**
+         * <code>optional bytes private = 2;</code>
+         */
+        public boolean hasPrivate() {
+          return ((bitField0_ & 0x00000002) == 0x00000002);
+        }
+        /**
+         * <code>optional bytes private = 2;</code>
+         */
+        public com.google.protobuf.ByteString getPrivate() {
+          return private_;
+        }
+        /**
+         * <code>optional bytes private = 2;</code>
+         */
+        public Builder setPrivate(com.google.protobuf.ByteString value) {
+          if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+          private_ = value;
+          onChanged();
+          return this;
+        }
+        /**
+         * <code>optional bytes private = 2;</code>
+         */
+        public Builder clearPrivate() {
+          bitField0_ = (bitField0_ & ~0x00000002);
+          private_ = getDefaultInstance().getPrivate();
+          onChanged();
+          return this;
+        }
+
+        // @@protoc_insertion_point(builder_scope:textsecure.SenderKeyStateStructure.SenderSigningKey)
+      }
+
+      static {
+        defaultInstance = new SenderSigningKey(true);
+        defaultInstance.initFields();
+      }
+
+      // @@protoc_insertion_point(class_scope:textsecure.SenderKeyStateStructure.SenderSigningKey)
+    }
+
+    private int bitField0_;
+    // optional uint32 senderKeyId = 1;
+    public static final int SENDERKEYID_FIELD_NUMBER = 1;
+    private int senderKeyId_;
+    /**
+     * <code>optional uint32 senderKeyId = 1;</code>
+     */
+    public boolean hasSenderKeyId() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional uint32 senderKeyId = 1;</code>
+     */
+    public int getSenderKeyId() {
+      return senderKeyId_;
+    }
+
+    // optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;
+    public static final int SENDERCHAINKEY_FIELD_NUMBER = 2;
+    private org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey senderChainKey_;
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+     */
+    public boolean hasSenderChainKey() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey getSenderChainKey() {
+      return senderChainKey_;
+    }
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKeyOrBuilder getSenderChainKeyOrBuilder() {
+      return senderChainKey_;
+    }
+
+    // optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;
+    public static final int SENDERSIGNINGKEY_FIELD_NUMBER = 3;
+    private org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey senderSigningKey_;
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+     */
+    public boolean hasSenderSigningKey() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey getSenderSigningKey() {
+      return senderSigningKey_;
+    }
+    /**
+     * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKeyOrBuilder getSenderSigningKeyOrBuilder() {
+      return senderSigningKey_;
+    }
+
+    // repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;
+    public static final int SENDERMESSAGEKEYS_FIELD_NUMBER = 4;
+    private java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey> senderMessageKeys_;
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+     */
+    public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey> getSenderMessageKeysList() {
+      return senderMessageKeys_;
+    }
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+     */
+    public java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKeyOrBuilder> 
+        getSenderMessageKeysOrBuilderList() {
+      return senderMessageKeys_;
+    }
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+     */
+    public int getSenderMessageKeysCount() {
+      return senderMessageKeys_.size();
+    }
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey getSenderMessageKeys(int index) {
+      return senderMessageKeys_.get(index);
+    }
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKeyOrBuilder getSenderMessageKeysOrBuilder(
+        int index) {
+      return senderMessageKeys_.get(index);
+    }
+
+    private void initFields() {
+      senderKeyId_ = 0;
+      senderChainKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.getDefaultInstance();
+      senderSigningKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.getDefaultInstance();
+      senderMessageKeys_ = java.util.Collections.emptyList();
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeUInt32(1, senderKeyId_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeMessage(2, senderChainKey_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeMessage(3, senderSigningKey_);
+      }
+      for (int i = 0; i < senderMessageKeys_.size(); i++) {
+        output.writeMessage(4, senderMessageKeys_.get(i));
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeUInt32Size(1, senderKeyId_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(2, senderChainKey_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(3, senderSigningKey_);
+      }
+      for (int i = 0; i < senderMessageKeys_.size(); i++) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(4, senderMessageKeys_.get(i));
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.SenderKeyStateStructure}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructureOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyStateStructure_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyStateStructure_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+          getSenderChainKeyFieldBuilder();
+          getSenderSigningKeyFieldBuilder();
+          getSenderMessageKeysFieldBuilder();
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        senderKeyId_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        if (senderChainKeyBuilder_ == null) {
+          senderChainKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.getDefaultInstance();
+        } else {
+          senderChainKeyBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000002);
+        if (senderSigningKeyBuilder_ == null) {
+          senderSigningKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.getDefaultInstance();
+        } else {
+          senderSigningKeyBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000004);
+        if (senderMessageKeysBuilder_ == null) {
+          senderMessageKeys_ = java.util.Collections.emptyList();
+          bitField0_ = (bitField0_ & ~0x00000008);
+        } else {
+          senderMessageKeysBuilder_.clear();
+        }
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyStateStructure_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure build() {
+        org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure buildPartial() {
+        org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure result = new org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.senderKeyId_ = senderKeyId_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        if (senderChainKeyBuilder_ == null) {
+          result.senderChainKey_ = senderChainKey_;
+        } else {
+          result.senderChainKey_ = senderChainKeyBuilder_.build();
+        }
+        if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        if (senderSigningKeyBuilder_ == null) {
+          result.senderSigningKey_ = senderSigningKey_;
+        } else {
+          result.senderSigningKey_ = senderSigningKeyBuilder_.build();
+        }
+        if (senderMessageKeysBuilder_ == null) {
+          if (((bitField0_ & 0x00000008) == 0x00000008)) {
+            senderMessageKeys_ = java.util.Collections.unmodifiableList(senderMessageKeys_);
+            bitField0_ = (bitField0_ & ~0x00000008);
+          }
+          result.senderMessageKeys_ = senderMessageKeys_;
+        } else {
+          result.senderMessageKeys_ = senderMessageKeysBuilder_.build();
+        }
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure) {
+          return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure other) {
+        if (other == org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.getDefaultInstance()) return this;
+        if (other.hasSenderKeyId()) {
+          setSenderKeyId(other.getSenderKeyId());
+        }
+        if (other.hasSenderChainKey()) {
+          mergeSenderChainKey(other.getSenderChainKey());
+        }
+        if (other.hasSenderSigningKey()) {
+          mergeSenderSigningKey(other.getSenderSigningKey());
+        }
+        if (senderMessageKeysBuilder_ == null) {
+          if (!other.senderMessageKeys_.isEmpty()) {
+            if (senderMessageKeys_.isEmpty()) {
+              senderMessageKeys_ = other.senderMessageKeys_;
+              bitField0_ = (bitField0_ & ~0x00000008);
+            } else {
+              ensureSenderMessageKeysIsMutable();
+              senderMessageKeys_.addAll(other.senderMessageKeys_);
+            }
+            onChanged();
+          }
+        } else {
+          if (!other.senderMessageKeys_.isEmpty()) {
+            if (senderMessageKeysBuilder_.isEmpty()) {
+              senderMessageKeysBuilder_.dispose();
+              senderMessageKeysBuilder_ = null;
+              senderMessageKeys_ = other.senderMessageKeys_;
+              bitField0_ = (bitField0_ & ~0x00000008);
+              senderMessageKeysBuilder_ = 
+                com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders ?
+                   getSenderMessageKeysFieldBuilder() : null;
+            } else {
+              senderMessageKeysBuilder_.addAllMessages(other.senderMessageKeys_);
+            }
+          }
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional uint32 senderKeyId = 1;
+      private int senderKeyId_ ;
+      /**
+       * <code>optional uint32 senderKeyId = 1;</code>
+       */
+      public boolean hasSenderKeyId() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional uint32 senderKeyId = 1;</code>
+       */
+      public int getSenderKeyId() {
+        return senderKeyId_;
+      }
+      /**
+       * <code>optional uint32 senderKeyId = 1;</code>
+       */
+      public Builder setSenderKeyId(int value) {
+        bitField0_ |= 0x00000001;
+        senderKeyId_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional uint32 senderKeyId = 1;</code>
+       */
+      public Builder clearSenderKeyId() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        senderKeyId_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;
+      private org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey senderChainKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.getDefaultInstance();
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKeyOrBuilder> senderChainKeyBuilder_;
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+       */
+      public boolean hasSenderChainKey() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey getSenderChainKey() {
+        if (senderChainKeyBuilder_ == null) {
+          return senderChainKey_;
+        } else {
+          return senderChainKeyBuilder_.getMessage();
+        }
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+       */
+      public Builder setSenderChainKey(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey value) {
+        if (senderChainKeyBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          senderChainKey_ = value;
+          onChanged();
+        } else {
+          senderChainKeyBuilder_.setMessage(value);
+        }
+        bitField0_ |= 0x00000002;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+       */
+      public Builder setSenderChainKey(
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.Builder builderForValue) {
+        if (senderChainKeyBuilder_ == null) {
+          senderChainKey_ = builderForValue.build();
+          onChanged();
+        } else {
+          senderChainKeyBuilder_.setMessage(builderForValue.build());
+        }
+        bitField0_ |= 0x00000002;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+       */
+      public Builder mergeSenderChainKey(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey value) {
+        if (senderChainKeyBuilder_ == null) {
+          if (((bitField0_ & 0x00000002) == 0x00000002) &&
+              senderChainKey_ != org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.getDefaultInstance()) {
+            senderChainKey_ =
+              org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.newBuilder(senderChainKey_).mergeFrom(value).buildPartial();
+          } else {
+            senderChainKey_ = value;
+          }
+          onChanged();
+        } else {
+          senderChainKeyBuilder_.mergeFrom(value);
+        }
+        bitField0_ |= 0x00000002;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+       */
+      public Builder clearSenderChainKey() {
+        if (senderChainKeyBuilder_ == null) {
+          senderChainKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.getDefaultInstance();
+          onChanged();
+        } else {
+          senderChainKeyBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000002);
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.Builder getSenderChainKeyBuilder() {
+        bitField0_ |= 0x00000002;
+        onChanged();
+        return getSenderChainKeyFieldBuilder().getBuilder();
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKeyOrBuilder getSenderChainKeyOrBuilder() {
+        if (senderChainKeyBuilder_ != null) {
+          return senderChainKeyBuilder_.getMessageOrBuilder();
+        } else {
+          return senderChainKey_;
+        }
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderChainKey senderChainKey = 2;</code>
+       */
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKeyOrBuilder> 
+          getSenderChainKeyFieldBuilder() {
+        if (senderChainKeyBuilder_ == null) {
+          senderChainKeyBuilder_ = new com.google.protobuf.SingleFieldBuilder<
+              org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderChainKeyOrBuilder>(
+                  senderChainKey_,
+                  getParentForChildren(),
+                  isClean());
+          senderChainKey_ = null;
+        }
+        return senderChainKeyBuilder_;
+      }
+
+      // optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;
+      private org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey senderSigningKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.getDefaultInstance();
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKeyOrBuilder> senderSigningKeyBuilder_;
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+       */
+      public boolean hasSenderSigningKey() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey getSenderSigningKey() {
+        if (senderSigningKeyBuilder_ == null) {
+          return senderSigningKey_;
+        } else {
+          return senderSigningKeyBuilder_.getMessage();
+        }
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+       */
+      public Builder setSenderSigningKey(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey value) {
+        if (senderSigningKeyBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          senderSigningKey_ = value;
+          onChanged();
+        } else {
+          senderSigningKeyBuilder_.setMessage(value);
+        }
+        bitField0_ |= 0x00000004;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+       */
+      public Builder setSenderSigningKey(
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.Builder builderForValue) {
+        if (senderSigningKeyBuilder_ == null) {
+          senderSigningKey_ = builderForValue.build();
+          onChanged();
+        } else {
+          senderSigningKeyBuilder_.setMessage(builderForValue.build());
+        }
+        bitField0_ |= 0x00000004;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+       */
+      public Builder mergeSenderSigningKey(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey value) {
+        if (senderSigningKeyBuilder_ == null) {
+          if (((bitField0_ & 0x00000004) == 0x00000004) &&
+              senderSigningKey_ != org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.getDefaultInstance()) {
+            senderSigningKey_ =
+              org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.newBuilder(senderSigningKey_).mergeFrom(value).buildPartial();
+          } else {
+            senderSigningKey_ = value;
+          }
+          onChanged();
+        } else {
+          senderSigningKeyBuilder_.mergeFrom(value);
+        }
+        bitField0_ |= 0x00000004;
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+       */
+      public Builder clearSenderSigningKey() {
+        if (senderSigningKeyBuilder_ == null) {
+          senderSigningKey_ = org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.getDefaultInstance();
+          onChanged();
+        } else {
+          senderSigningKeyBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000004);
+        return this;
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.Builder getSenderSigningKeyBuilder() {
+        bitField0_ |= 0x00000004;
+        onChanged();
+        return getSenderSigningKeyFieldBuilder().getBuilder();
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKeyOrBuilder getSenderSigningKeyOrBuilder() {
+        if (senderSigningKeyBuilder_ != null) {
+          return senderSigningKeyBuilder_.getMessageOrBuilder();
+        } else {
+          return senderSigningKey_;
+        }
+      }
+      /**
+       * <code>optional .textsecure.SenderKeyStateStructure.SenderSigningKey senderSigningKey = 3;</code>
+       */
+      private com.google.protobuf.SingleFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKeyOrBuilder> 
+          getSenderSigningKeyFieldBuilder() {
+        if (senderSigningKeyBuilder_ == null) {
+          senderSigningKeyBuilder_ = new com.google.protobuf.SingleFieldBuilder<
+              org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderSigningKeyOrBuilder>(
+                  senderSigningKey_,
+                  getParentForChildren(),
+                  isClean());
+          senderSigningKey_ = null;
+        }
+        return senderSigningKeyBuilder_;
+      }
+
+      // repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;
+      private java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey> senderMessageKeys_ =
+        java.util.Collections.emptyList();
+      private void ensureSenderMessageKeysIsMutable() {
+        if (!((bitField0_ & 0x00000008) == 0x00000008)) {
+          senderMessageKeys_ = new java.util.ArrayList<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey>(senderMessageKeys_);
+          bitField0_ |= 0x00000008;
+         }
+      }
+
+      private com.google.protobuf.RepeatedFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKeyOrBuilder> senderMessageKeysBuilder_;
+
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey> getSenderMessageKeysList() {
+        if (senderMessageKeysBuilder_ == null) {
+          return java.util.Collections.unmodifiableList(senderMessageKeys_);
+        } else {
+          return senderMessageKeysBuilder_.getMessageList();
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public int getSenderMessageKeysCount() {
+        if (senderMessageKeysBuilder_ == null) {
+          return senderMessageKeys_.size();
+        } else {
+          return senderMessageKeysBuilder_.getCount();
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey getSenderMessageKeys(int index) {
+        if (senderMessageKeysBuilder_ == null) {
+          return senderMessageKeys_.get(index);
+        } else {
+          return senderMessageKeysBuilder_.getMessage(index);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public Builder setSenderMessageKeys(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey value) {
+        if (senderMessageKeysBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensureSenderMessageKeysIsMutable();
+          senderMessageKeys_.set(index, value);
+          onChanged();
+        } else {
+          senderMessageKeysBuilder_.setMessage(index, value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public Builder setSenderMessageKeys(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.Builder builderForValue) {
+        if (senderMessageKeysBuilder_ == null) {
+          ensureSenderMessageKeysIsMutable();
+          senderMessageKeys_.set(index, builderForValue.build());
+          onChanged();
+        } else {
+          senderMessageKeysBuilder_.setMessage(index, builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public Builder addSenderMessageKeys(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey value) {
+        if (senderMessageKeysBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensureSenderMessageKeysIsMutable();
+          senderMessageKeys_.add(value);
+          onChanged();
+        } else {
+          senderMessageKeysBuilder_.addMessage(value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public Builder addSenderMessageKeys(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey value) {
+        if (senderMessageKeysBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensureSenderMessageKeysIsMutable();
+          senderMessageKeys_.add(index, value);
+          onChanged();
+        } else {
+          senderMessageKeysBuilder_.addMessage(index, value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public Builder addSenderMessageKeys(
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.Builder builderForValue) {
+        if (senderMessageKeysBuilder_ == null) {
+          ensureSenderMessageKeysIsMutable();
+          senderMessageKeys_.add(builderForValue.build());
+          onChanged();
+        } else {
+          senderMessageKeysBuilder_.addMessage(builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public Builder addSenderMessageKeys(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.Builder builderForValue) {
+        if (senderMessageKeysBuilder_ == null) {
+          ensureSenderMessageKeysIsMutable();
+          senderMessageKeys_.add(index, builderForValue.build());
+          onChanged();
+        } else {
+          senderMessageKeysBuilder_.addMessage(index, builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public Builder addAllSenderMessageKeys(
+          java.lang.Iterable<? extends org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey> values) {
+        if (senderMessageKeysBuilder_ == null) {
+          ensureSenderMessageKeysIsMutable();
+          super.addAll(values, senderMessageKeys_);
+          onChanged();
+        } else {
+          senderMessageKeysBuilder_.addAllMessages(values);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public Builder clearSenderMessageKeys() {
+        if (senderMessageKeysBuilder_ == null) {
+          senderMessageKeys_ = java.util.Collections.emptyList();
+          bitField0_ = (bitField0_ & ~0x00000008);
+          onChanged();
+        } else {
+          senderMessageKeysBuilder_.clear();
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public Builder removeSenderMessageKeys(int index) {
+        if (senderMessageKeysBuilder_ == null) {
+          ensureSenderMessageKeysIsMutable();
+          senderMessageKeys_.remove(index);
+          onChanged();
+        } else {
+          senderMessageKeysBuilder_.remove(index);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.Builder getSenderMessageKeysBuilder(
+          int index) {
+        return getSenderMessageKeysFieldBuilder().getBuilder(index);
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKeyOrBuilder getSenderMessageKeysOrBuilder(
+          int index) {
+        if (senderMessageKeysBuilder_ == null) {
+          return senderMessageKeys_.get(index);  } else {
+          return senderMessageKeysBuilder_.getMessageOrBuilder(index);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKeyOrBuilder> 
+           getSenderMessageKeysOrBuilderList() {
+        if (senderMessageKeysBuilder_ != null) {
+          return senderMessageKeysBuilder_.getMessageOrBuilderList();
+        } else {
+          return java.util.Collections.unmodifiableList(senderMessageKeys_);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.Builder addSenderMessageKeysBuilder() {
+        return getSenderMessageKeysFieldBuilder().addBuilder(
+            org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.getDefaultInstance());
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.Builder addSenderMessageKeysBuilder(
+          int index) {
+        return getSenderMessageKeysFieldBuilder().addBuilder(
+            index, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.getDefaultInstance());
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure.SenderMessageKey senderMessageKeys = 4;</code>
+       */
+      public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.Builder> 
+           getSenderMessageKeysBuilderList() {
+        return getSenderMessageKeysFieldBuilder().getBuilderList();
+      }
+      private com.google.protobuf.RepeatedFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKeyOrBuilder> 
+          getSenderMessageKeysFieldBuilder() {
+        if (senderMessageKeysBuilder_ == null) {
+          senderMessageKeysBuilder_ = new com.google.protobuf.RepeatedFieldBuilder<
+              org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKey.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.SenderMessageKeyOrBuilder>(
+                  senderMessageKeys_,
+                  ((bitField0_ & 0x00000008) == 0x00000008),
+                  getParentForChildren(),
+                  isClean());
+          senderMessageKeys_ = null;
+        }
+        return senderMessageKeysBuilder_;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.SenderKeyStateStructure)
+    }
+
+    static {
+      defaultInstance = new SenderKeyStateStructure(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.SenderKeyStateStructure)
+  }
+
+  public interface SenderKeyRecordStructureOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+     */
+    java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure> 
+        getSenderKeyStatesList();
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure getSenderKeyStates(int index);
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+     */
+    int getSenderKeyStatesCount();
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+     */
+    java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructureOrBuilder> 
+        getSenderKeyStatesOrBuilderList();
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+     */
+    org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructureOrBuilder getSenderKeyStatesOrBuilder(
+        int index);
+  }
+  /**
+   * Protobuf type {@code textsecure.SenderKeyRecordStructure}
+   */
+  public static final class SenderKeyRecordStructure extends
+      com.google.protobuf.GeneratedMessage
+      implements SenderKeyRecordStructureOrBuilder {
+    // Use SenderKeyRecordStructure.newBuilder() to construct.
+    private SenderKeyRecordStructure(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private SenderKeyRecordStructure(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final SenderKeyRecordStructure defaultInstance;
+    public static SenderKeyRecordStructure getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public SenderKeyRecordStructure getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private SenderKeyRecordStructure(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 10: {
+              if (!((mutable_bitField0_ & 0x00000001) == 0x00000001)) {
+                senderKeyStates_ = new java.util.ArrayList<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure>();
+                mutable_bitField0_ |= 0x00000001;
+              }
+              senderKeyStates_.add(input.readMessage(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.PARSER, extensionRegistry));
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        if (((mutable_bitField0_ & 0x00000001) == 0x00000001)) {
+          senderKeyStates_ = java.util.Collections.unmodifiableList(senderKeyStates_);
+        }
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyRecordStructure_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyRecordStructure_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<SenderKeyRecordStructure> PARSER =
+        new com.google.protobuf.AbstractParser<SenderKeyRecordStructure>() {
+      public SenderKeyRecordStructure parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new SenderKeyRecordStructure(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<SenderKeyRecordStructure> getParserForType() {
+      return PARSER;
+    }
+
+    // repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;
+    public static final int SENDERKEYSTATES_FIELD_NUMBER = 1;
+    private java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure> senderKeyStates_;
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+     */
+    public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure> getSenderKeyStatesList() {
+      return senderKeyStates_;
+    }
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+     */
+    public java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructureOrBuilder> 
+        getSenderKeyStatesOrBuilderList() {
+      return senderKeyStates_;
+    }
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+     */
+    public int getSenderKeyStatesCount() {
+      return senderKeyStates_.size();
+    }
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure getSenderKeyStates(int index) {
+      return senderKeyStates_.get(index);
+    }
+    /**
+     * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+     */
+    public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructureOrBuilder getSenderKeyStatesOrBuilder(
+        int index) {
+      return senderKeyStates_.get(index);
+    }
+
+    private void initFields() {
+      senderKeyStates_ = java.util.Collections.emptyList();
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      for (int i = 0; i < senderKeyStates_.size(); i++) {
+        output.writeMessage(1, senderKeyStates_.get(i));
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      for (int i = 0; i < senderKeyStates_.size(); i++) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(1, senderKeyStates_.get(i));
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code textsecure.SenderKeyRecordStructure}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructureOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyRecordStructure_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyRecordStructure_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure.class, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure.Builder.class);
+      }
+
+      // Construct using org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+          getSenderKeyStatesFieldBuilder();
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        if (senderKeyStatesBuilder_ == null) {
+          senderKeyStates_ = java.util.Collections.emptyList();
+          bitField0_ = (bitField0_ & ~0x00000001);
+        } else {
+          senderKeyStatesBuilder_.clear();
+        }
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.internal_static_textsecure_SenderKeyRecordStructure_descriptor;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure getDefaultInstanceForType() {
+        return org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure.getDefaultInstance();
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure build() {
+        org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure buildPartial() {
+        org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure result = new org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure(this);
+        int from_bitField0_ = bitField0_;
+        if (senderKeyStatesBuilder_ == null) {
+          if (((bitField0_ & 0x00000001) == 0x00000001)) {
+            senderKeyStates_ = java.util.Collections.unmodifiableList(senderKeyStates_);
+            bitField0_ = (bitField0_ & ~0x00000001);
+          }
+          result.senderKeyStates_ = senderKeyStates_;
+        } else {
+          result.senderKeyStates_ = senderKeyStatesBuilder_.build();
+        }
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure) {
+          return mergeFrom((org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure other) {
+        if (other == org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure.getDefaultInstance()) return this;
+        if (senderKeyStatesBuilder_ == null) {
+          if (!other.senderKeyStates_.isEmpty()) {
+            if (senderKeyStates_.isEmpty()) {
+              senderKeyStates_ = other.senderKeyStates_;
+              bitField0_ = (bitField0_ & ~0x00000001);
+            } else {
+              ensureSenderKeyStatesIsMutable();
+              senderKeyStates_.addAll(other.senderKeyStates_);
+            }
+            onChanged();
+          }
+        } else {
+          if (!other.senderKeyStates_.isEmpty()) {
+            if (senderKeyStatesBuilder_.isEmpty()) {
+              senderKeyStatesBuilder_.dispose();
+              senderKeyStatesBuilder_ = null;
+              senderKeyStates_ = other.senderKeyStates_;
+              bitField0_ = (bitField0_ & ~0x00000001);
+              senderKeyStatesBuilder_ = 
+                com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders ?
+                   getSenderKeyStatesFieldBuilder() : null;
+            } else {
+              senderKeyStatesBuilder_.addAllMessages(other.senderKeyStates_);
+            }
+          }
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;
+      private java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure> senderKeyStates_ =
+        java.util.Collections.emptyList();
+      private void ensureSenderKeyStatesIsMutable() {
+        if (!((bitField0_ & 0x00000001) == 0x00000001)) {
+          senderKeyStates_ = new java.util.ArrayList<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure>(senderKeyStates_);
+          bitField0_ |= 0x00000001;
+         }
+      }
+
+      private com.google.protobuf.RepeatedFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructureOrBuilder> senderKeyStatesBuilder_;
+
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure> getSenderKeyStatesList() {
+        if (senderKeyStatesBuilder_ == null) {
+          return java.util.Collections.unmodifiableList(senderKeyStates_);
+        } else {
+          return senderKeyStatesBuilder_.getMessageList();
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public int getSenderKeyStatesCount() {
+        if (senderKeyStatesBuilder_ == null) {
+          return senderKeyStates_.size();
+        } else {
+          return senderKeyStatesBuilder_.getCount();
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure getSenderKeyStates(int index) {
+        if (senderKeyStatesBuilder_ == null) {
+          return senderKeyStates_.get(index);
+        } else {
+          return senderKeyStatesBuilder_.getMessage(index);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public Builder setSenderKeyStates(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure value) {
+        if (senderKeyStatesBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensureSenderKeyStatesIsMutable();
+          senderKeyStates_.set(index, value);
+          onChanged();
+        } else {
+          senderKeyStatesBuilder_.setMessage(index, value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public Builder setSenderKeyStates(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.Builder builderForValue) {
+        if (senderKeyStatesBuilder_ == null) {
+          ensureSenderKeyStatesIsMutable();
+          senderKeyStates_.set(index, builderForValue.build());
+          onChanged();
+        } else {
+          senderKeyStatesBuilder_.setMessage(index, builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public Builder addSenderKeyStates(org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure value) {
+        if (senderKeyStatesBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensureSenderKeyStatesIsMutable();
+          senderKeyStates_.add(value);
+          onChanged();
+        } else {
+          senderKeyStatesBuilder_.addMessage(value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public Builder addSenderKeyStates(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure value) {
+        if (senderKeyStatesBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          ensureSenderKeyStatesIsMutable();
+          senderKeyStates_.add(index, value);
+          onChanged();
+        } else {
+          senderKeyStatesBuilder_.addMessage(index, value);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public Builder addSenderKeyStates(
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.Builder builderForValue) {
+        if (senderKeyStatesBuilder_ == null) {
+          ensureSenderKeyStatesIsMutable();
+          senderKeyStates_.add(builderForValue.build());
+          onChanged();
+        } else {
+          senderKeyStatesBuilder_.addMessage(builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public Builder addSenderKeyStates(
+          int index, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.Builder builderForValue) {
+        if (senderKeyStatesBuilder_ == null) {
+          ensureSenderKeyStatesIsMutable();
+          senderKeyStates_.add(index, builderForValue.build());
+          onChanged();
+        } else {
+          senderKeyStatesBuilder_.addMessage(index, builderForValue.build());
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public Builder addAllSenderKeyStates(
+          java.lang.Iterable<? extends org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure> values) {
+        if (senderKeyStatesBuilder_ == null) {
+          ensureSenderKeyStatesIsMutable();
+          super.addAll(values, senderKeyStates_);
+          onChanged();
+        } else {
+          senderKeyStatesBuilder_.addAllMessages(values);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public Builder clearSenderKeyStates() {
+        if (senderKeyStatesBuilder_ == null) {
+          senderKeyStates_ = java.util.Collections.emptyList();
+          bitField0_ = (bitField0_ & ~0x00000001);
+          onChanged();
+        } else {
+          senderKeyStatesBuilder_.clear();
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public Builder removeSenderKeyStates(int index) {
+        if (senderKeyStatesBuilder_ == null) {
+          ensureSenderKeyStatesIsMutable();
+          senderKeyStates_.remove(index);
+          onChanged();
+        } else {
+          senderKeyStatesBuilder_.remove(index);
+        }
+        return this;
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.Builder getSenderKeyStatesBuilder(
+          int index) {
+        return getSenderKeyStatesFieldBuilder().getBuilder(index);
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructureOrBuilder getSenderKeyStatesOrBuilder(
+          int index) {
+        if (senderKeyStatesBuilder_ == null) {
+          return senderKeyStates_.get(index);  } else {
+          return senderKeyStatesBuilder_.getMessageOrBuilder(index);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public java.util.List<? extends org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructureOrBuilder> 
+           getSenderKeyStatesOrBuilderList() {
+        if (senderKeyStatesBuilder_ != null) {
+          return senderKeyStatesBuilder_.getMessageOrBuilderList();
+        } else {
+          return java.util.Collections.unmodifiableList(senderKeyStates_);
+        }
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.Builder addSenderKeyStatesBuilder() {
+        return getSenderKeyStatesFieldBuilder().addBuilder(
+            org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.getDefaultInstance());
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.Builder addSenderKeyStatesBuilder(
+          int index) {
+        return getSenderKeyStatesFieldBuilder().addBuilder(
+            index, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.getDefaultInstance());
+      }
+      /**
+       * <code>repeated .textsecure.SenderKeyStateStructure senderKeyStates = 1;</code>
+       */
+      public java.util.List<org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.Builder> 
+           getSenderKeyStatesBuilderList() {
+        return getSenderKeyStatesFieldBuilder().getBuilderList();
+      }
+      private com.google.protobuf.RepeatedFieldBuilder<
+          org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructureOrBuilder> 
+          getSenderKeyStatesFieldBuilder() {
+        if (senderKeyStatesBuilder_ == null) {
+          senderKeyStatesBuilder_ = new com.google.protobuf.RepeatedFieldBuilder<
+              org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure.Builder, org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructureOrBuilder>(
+                  senderKeyStates_,
+                  ((bitField0_ & 0x00000001) == 0x00000001),
+                  getParentForChildren(),
+                  isClean());
+          senderKeyStates_ = null;
+        }
+        return senderKeyStatesBuilder_;
+      }
+
+      // @@protoc_insertion_point(builder_scope:textsecure.SenderKeyRecordStructure)
+    }
+
+    static {
+      defaultInstance = new SenderKeyRecordStructure(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:textsecure.SenderKeyRecordStructure)
+  }
+
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SessionStructure_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SessionStructure_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SessionStructure_Chain_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SessionStructure_Chain_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SessionStructure_Chain_ChainKey_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SessionStructure_Chain_ChainKey_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SessionStructure_Chain_MessageKey_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SessionStructure_Chain_MessageKey_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SessionStructure_PendingKeyExchange_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SessionStructure_PendingKeyExchange_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SessionStructure_PendingPreKey_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SessionStructure_PendingPreKey_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_RecordStructure_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_RecordStructure_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_PreKeyRecordStructure_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_PreKeyRecordStructure_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SignedPreKeyRecordStructure_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SignedPreKeyRecordStructure_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_IdentityKeyPairStructure_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_IdentityKeyPairStructure_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SenderKeyStateStructure_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SenderKeyStateStructure_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SenderKeyStateStructure_SenderChainKey_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SenderKeyStateStructure_SenderChainKey_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SenderKeyStateStructure_SenderMessageKey_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SenderKeyStateStructure_SenderMessageKey_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SenderKeyStateStructure_SenderSigningKey_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SenderKeyStateStructure_SenderSigningKey_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_textsecure_SenderKeyRecordStructure_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_textsecure_SenderKeyRecordStructure_fieldAccessorTable;
+
+  public static com.google.protobuf.Descriptors.FileDescriptor
+      getDescriptor() {
+    return descriptor;
+  }
+  private static com.google.protobuf.Descriptors.FileDescriptor
+      descriptor;
+  static {
+    java.lang.String[] descriptorData = {
+      "\n\032LocalStorageProtocol.proto\022\ntextsecure" +
+      "\"\323\010\n\020SessionStructure\022\026\n\016sessionVersion\030" +
+      "\001 \001(\r\022\033\n\023localIdentityPublic\030\002 \001(\014\022\034\n\024re" +
+      "moteIdentityPublic\030\003 \001(\014\022\017\n\007rootKey\030\004 \001(" +
+      "\014\022\027\n\017previousCounter\030\005 \001(\r\0227\n\013senderChai" +
+      "n\030\006 \001(\0132\".textsecure.SessionStructure.Ch" +
+      "ain\022:\n\016receiverChains\030\007 \003(\0132\".textsecure" +
+      ".SessionStructure.Chain\022K\n\022pendingKeyExc" +
+      "hange\030\010 \001(\0132/.textsecure.SessionStructur" +
+      "e.PendingKeyExchange\022A\n\rpendingPreKey\030\t ",
+      "\001(\0132*.textsecure.SessionStructure.Pendin" +
+      "gPreKey\022\034\n\024remoteRegistrationId\030\n \001(\r\022\033\n" +
+      "\023localRegistrationId\030\013 \001(\r\022\024\n\014needsRefre" +
+      "sh\030\014 \001(\010\022\024\n\014aliceBaseKey\030\r \001(\014\032\271\002\n\005Chain" +
+      "\022\030\n\020senderRatchetKey\030\001 \001(\014\022\037\n\027senderRatc" +
+      "hetKeyPrivate\030\002 \001(\014\022=\n\010chainKey\030\003 \001(\0132+." +
+      "textsecure.SessionStructure.Chain.ChainK" +
+      "ey\022B\n\013messageKeys\030\004 \003(\0132-.textsecure.Ses" +
+      "sionStructure.Chain.MessageKey\032&\n\010ChainK" +
+      "ey\022\r\n\005index\030\001 \001(\r\022\013\n\003key\030\002 \001(\014\032J\n\nMessag",
+      "eKey\022\r\n\005index\030\001 \001(\r\022\021\n\tcipherKey\030\002 \001(\014\022\016" +
+      "\n\006macKey\030\003 \001(\014\022\n\n\002iv\030\004 \001(\014\032\315\001\n\022PendingKe" +
+      "yExchange\022\020\n\010sequence\030\001 \001(\r\022\024\n\014localBase" +
+      "Key\030\002 \001(\014\022\033\n\023localBaseKeyPrivate\030\003 \001(\014\022\027" +
+      "\n\017localRatchetKey\030\004 \001(\014\022\036\n\026localRatchetK" +
+      "eyPrivate\030\005 \001(\014\022\030\n\020localIdentityKey\030\007 \001(" +
+      "\014\022\037\n\027localIdentityKeyPrivate\030\010 \001(\014\032J\n\rPe" +
+      "ndingPreKey\022\020\n\010preKeyId\030\001 \001(\r\022\026\n\016signedP" +
+      "reKeyId\030\003 \001(\005\022\017\n\007baseKey\030\002 \001(\014\"\177\n\017Record" +
+      "Structure\0224\n\016currentSession\030\001 \001(\0132\034.text",
+      "secure.SessionStructure\0226\n\020previousSessi" +
+      "ons\030\002 \003(\0132\034.textsecure.SessionStructure\"" +
+      "J\n\025PreKeyRecordStructure\022\n\n\002id\030\001 \001(\r\022\021\n\t" +
+      "publicKey\030\002 \001(\014\022\022\n\nprivateKey\030\003 \001(\014\"v\n\033S" +
+      "ignedPreKeyRecordStructure\022\n\n\002id\030\001 \001(\r\022\021" +
+      "\n\tpublicKey\030\002 \001(\014\022\022\n\nprivateKey\030\003 \001(\014\022\021\n" +
+      "\tsignature\030\004 \001(\014\022\021\n\ttimestamp\030\005 \001(\006\"A\n\030I" +
+      "dentityKeyPairStructure\022\021\n\tpublicKey\030\001 \001" +
+      "(\014\022\022\n\nprivateKey\030\002 \001(\014\"\270\003\n\027SenderKeyStat" +
+      "eStructure\022\023\n\013senderKeyId\030\001 \001(\r\022J\n\016sende",
+      "rChainKey\030\002 \001(\01322.textsecure.SenderKeySt" +
+      "ateStructure.SenderChainKey\022N\n\020senderSig" +
+      "ningKey\030\003 \001(\01324.textsecure.SenderKeyStat" +
+      "eStructure.SenderSigningKey\022O\n\021senderMes" +
+      "sageKeys\030\004 \003(\01324.textsecure.SenderKeySta" +
+      "teStructure.SenderMessageKey\0321\n\016SenderCh" +
+      "ainKey\022\021\n\titeration\030\001 \001(\r\022\014\n\004seed\030\002 \001(\014\032" +
+      "3\n\020SenderMessageKey\022\021\n\titeration\030\001 \001(\r\022\014" +
+      "\n\004seed\030\002 \001(\014\0323\n\020SenderSigningKey\022\016\n\006publ" +
+      "ic\030\001 \001(\014\022\017\n\007private\030\002 \001(\014\"X\n\030SenderKeyRe",
+      "cordStructure\022<\n\017senderKeyStates\030\001 \003(\0132#" +
+      ".textsecure.SenderKeyStateStructureB4\n#o" +
+      "rg.whispersystems.libaxolotl.stateB\rStor" +
+      "ageProtos"
+    };
+    com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
+      new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
+        public com.google.protobuf.ExtensionRegistry assignDescriptors(
+            com.google.protobuf.Descriptors.FileDescriptor root) {
+          descriptor = root;
+          internal_static_textsecure_SessionStructure_descriptor =
+            getDescriptor().getMessageTypes().get(0);
+          internal_static_textsecure_SessionStructure_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SessionStructure_descriptor,
+              new java.lang.String[] { "SessionVersion", "LocalIdentityPublic", "RemoteIdentityPublic", "RootKey", "PreviousCounter", "SenderChain", "ReceiverChains", "PendingKeyExchange", "PendingPreKey", "RemoteRegistrationId", "LocalRegistrationId", "NeedsRefresh", "AliceBaseKey", });
+          internal_static_textsecure_SessionStructure_Chain_descriptor =
+            internal_static_textsecure_SessionStructure_descriptor.getNestedTypes().get(0);
+          internal_static_textsecure_SessionStructure_Chain_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SessionStructure_Chain_descriptor,
+              new java.lang.String[] { "SenderRatchetKey", "SenderRatchetKeyPrivate", "ChainKey", "MessageKeys", });
+          internal_static_textsecure_SessionStructure_Chain_ChainKey_descriptor =
+            internal_static_textsecure_SessionStructure_Chain_descriptor.getNestedTypes().get(0);
+          internal_static_textsecure_SessionStructure_Chain_ChainKey_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SessionStructure_Chain_ChainKey_descriptor,
+              new java.lang.String[] { "Index", "Key", });
+          internal_static_textsecure_SessionStructure_Chain_MessageKey_descriptor =
+            internal_static_textsecure_SessionStructure_Chain_descriptor.getNestedTypes().get(1);
+          internal_static_textsecure_SessionStructure_Chain_MessageKey_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SessionStructure_Chain_MessageKey_descriptor,
+              new java.lang.String[] { "Index", "CipherKey", "MacKey", "Iv", });
+          internal_static_textsecure_SessionStructure_PendingKeyExchange_descriptor =
+            internal_static_textsecure_SessionStructure_descriptor.getNestedTypes().get(1);
+          internal_static_textsecure_SessionStructure_PendingKeyExchange_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SessionStructure_PendingKeyExchange_descriptor,
+              new java.lang.String[] { "Sequence", "LocalBaseKey", "LocalBaseKeyPrivate", "LocalRatchetKey", "LocalRatchetKeyPrivate", "LocalIdentityKey", "LocalIdentityKeyPrivate", });
+          internal_static_textsecure_SessionStructure_PendingPreKey_descriptor =
+            internal_static_textsecure_SessionStructure_descriptor.getNestedTypes().get(2);
+          internal_static_textsecure_SessionStructure_PendingPreKey_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SessionStructure_PendingPreKey_descriptor,
+              new java.lang.String[] { "PreKeyId", "SignedPreKeyId", "BaseKey", });
+          internal_static_textsecure_RecordStructure_descriptor =
+            getDescriptor().getMessageTypes().get(1);
+          internal_static_textsecure_RecordStructure_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_RecordStructure_descriptor,
+              new java.lang.String[] { "CurrentSession", "PreviousSessions", });
+          internal_static_textsecure_PreKeyRecordStructure_descriptor =
+            getDescriptor().getMessageTypes().get(2);
+          internal_static_textsecure_PreKeyRecordStructure_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_PreKeyRecordStructure_descriptor,
+              new java.lang.String[] { "Id", "PublicKey", "PrivateKey", });
+          internal_static_textsecure_SignedPreKeyRecordStructure_descriptor =
+            getDescriptor().getMessageTypes().get(3);
+          internal_static_textsecure_SignedPreKeyRecordStructure_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SignedPreKeyRecordStructure_descriptor,
+              new java.lang.String[] { "Id", "PublicKey", "PrivateKey", "Signature", "Timestamp", });
+          internal_static_textsecure_IdentityKeyPairStructure_descriptor =
+            getDescriptor().getMessageTypes().get(4);
+          internal_static_textsecure_IdentityKeyPairStructure_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_IdentityKeyPairStructure_descriptor,
+              new java.lang.String[] { "PublicKey", "PrivateKey", });
+          internal_static_textsecure_SenderKeyStateStructure_descriptor =
+            getDescriptor().getMessageTypes().get(5);
+          internal_static_textsecure_SenderKeyStateStructure_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SenderKeyStateStructure_descriptor,
+              new java.lang.String[] { "SenderKeyId", "SenderChainKey", "SenderSigningKey", "SenderMessageKeys", });
+          internal_static_textsecure_SenderKeyStateStructure_SenderChainKey_descriptor =
+            internal_static_textsecure_SenderKeyStateStructure_descriptor.getNestedTypes().get(0);
+          internal_static_textsecure_SenderKeyStateStructure_SenderChainKey_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SenderKeyStateStructure_SenderChainKey_descriptor,
+              new java.lang.String[] { "Iteration", "Seed", });
+          internal_static_textsecure_SenderKeyStateStructure_SenderMessageKey_descriptor =
+            internal_static_textsecure_SenderKeyStateStructure_descriptor.getNestedTypes().get(1);
+          internal_static_textsecure_SenderKeyStateStructure_SenderMessageKey_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SenderKeyStateStructure_SenderMessageKey_descriptor,
+              new java.lang.String[] { "Iteration", "Seed", });
+          internal_static_textsecure_SenderKeyStateStructure_SenderSigningKey_descriptor =
+            internal_static_textsecure_SenderKeyStateStructure_descriptor.getNestedTypes().get(2);
+          internal_static_textsecure_SenderKeyStateStructure_SenderSigningKey_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SenderKeyStateStructure_SenderSigningKey_descriptor,
+              new java.lang.String[] { "Public", "Private", });
+          internal_static_textsecure_SenderKeyRecordStructure_descriptor =
+            getDescriptor().getMessageTypes().get(6);
+          internal_static_textsecure_SenderKeyRecordStructure_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_textsecure_SenderKeyRecordStructure_descriptor,
+              new java.lang.String[] { "SenderKeyStates", });
+          return null;
+        }
+      };
+    com.google.protobuf.Descriptors.FileDescriptor
+      .internalBuildGeneratedFileFrom(descriptorData,
+        new com.google.protobuf.Descriptors.FileDescriptor[] {
+        }, assigner);
+  }
+
+  // @@protoc_insertion_point(outer_class_scope)
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/ByteUtil.java b/src/main/java/org/whispersystems/libaxolotl/util/ByteUtil.java
new file mode 100644
index 00000000..c213ba0b
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/util/ByteUtil.java
@@ -0,0 +1,248 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.util;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.text.ParseException;
+
+public class ByteUtil {
+
+  public static byte[] combine(byte[]... elements) {
+    try {
+      ByteArrayOutputStream baos = new ByteArrayOutputStream();
+
+      for (byte[] element : elements) {
+        baos.write(element);
+      }
+
+      return baos.toByteArray();
+    } catch (IOException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public static byte[][] split(byte[] input, int firstLength, int secondLength) {
+    byte[][] parts = new byte[2][];
+
+    parts[0] = new byte[firstLength];
+    System.arraycopy(input, 0, parts[0], 0, firstLength);
+
+    parts[1] = new byte[secondLength];
+    System.arraycopy(input, firstLength, parts[1], 0, secondLength);
+
+    return parts;
+  }
+
+  public static byte[][] split(byte[] input, int firstLength, int secondLength, int thirdLength)
+      throws ParseException
+  {
+    if (input == null || firstLength < 0 || secondLength < 0 || thirdLength < 0 ||
+        input.length < firstLength + secondLength + thirdLength)
+    {
+      throw new ParseException("Input too small: " + (input == null ? null : Hex.toString(input)), 0);
+    }
+
+    byte[][] parts = new byte[3][];
+
+    parts[0] = new byte[firstLength];
+    System.arraycopy(input, 0, parts[0], 0, firstLength);
+
+    parts[1] = new byte[secondLength];
+    System.arraycopy(input, firstLength, parts[1], 0, secondLength);
+
+    parts[2] = new byte[thirdLength];
+    System.arraycopy(input, firstLength + secondLength, parts[2], 0, thirdLength);
+
+    return parts;
+  }
+
+  public static byte[] trim(byte[] input, int length) {
+    byte[] result = new byte[length];
+    System.arraycopy(input, 0, result, 0, result.length);
+
+    return result;
+  }
+
+  public static byte[] copyFrom(byte[] input) {
+    byte[] output = new byte[input.length];
+    System.arraycopy(input, 0, output, 0, output.length);
+
+    return output;
+  }
+
+  public static byte intsToByteHighAndLow(int highValue, int lowValue) {
+    return (byte)((highValue << 4 | lowValue) & 0xFF);
+  }
+
+  public static int highBitsToInt(byte value) {
+    return (value & 0xFF) >> 4;
+  }
+
+  public static int lowBitsToInt(byte value) {
+    return (value & 0xF);
+  }
+
+  public static int highBitsToMedium(int value) {
+    return (value >> 12);
+  }
+
+  public static int lowBitsToMedium(int value) {
+    return (value & 0xFFF);
+  }
+
+  public static byte[] shortToByteArray(int value) {
+    byte[] bytes = new byte[2];
+    shortToByteArray(bytes, 0, value);
+    return bytes;
+  }
+
+  public static int shortToByteArray(byte[] bytes, int offset, int value) {
+    bytes[offset+1] = (byte)value;
+    bytes[offset]   = (byte)(value >> 8);
+    return 2;
+  }
+
+  public static int shortToLittleEndianByteArray(byte[] bytes, int offset, int value) {
+    bytes[offset]   = (byte)value;
+    bytes[offset+1] = (byte)(value >> 8);
+    return 2;
+  }
+
+  public static byte[] mediumToByteArray(int value) {
+    byte[] bytes = new byte[3];
+    mediumToByteArray(bytes, 0, value);
+    return bytes;
+  }
+
+  public static int mediumToByteArray(byte[] bytes, int offset, int value) {
+    bytes[offset + 2] = (byte)value;
+    bytes[offset + 1] = (byte)(value >> 8);
+    bytes[offset]     = (byte)(value >> 16);
+    return 3;
+  }
+
+  public static byte[] intToByteArray(int value) {
+    byte[] bytes = new byte[4];
+    intToByteArray(bytes, 0, value);
+    return bytes;
+  }
+
+  public static int intToByteArray(byte[] bytes, int offset, int value) {
+    bytes[offset + 3] = (byte)value;
+    bytes[offset + 2] = (byte)(value >> 8);
+    bytes[offset + 1] = (byte)(value >> 16);
+    bytes[offset]     = (byte)(value >> 24);
+    return 4;
+  }
+
+  public static int intToLittleEndianByteArray(byte[] bytes, int offset, int value) {
+    bytes[offset]   = (byte)value;
+    bytes[offset+1] = (byte)(value >> 8);
+    bytes[offset+2] = (byte)(value >> 16);
+    bytes[offset+3] = (byte)(value >> 24);
+    return 4;
+  }
+
+  public static byte[] longToByteArray(long l) {
+    byte[] bytes = new byte[8];
+    longToByteArray(bytes, 0, l);
+    return bytes;
+  }
+
+  public static int longToByteArray(byte[] bytes, int offset, long value) {
+    bytes[offset + 7] = (byte)value;
+    bytes[offset + 6] = (byte)(value >> 8);
+    bytes[offset + 5] = (byte)(value >> 16);
+    bytes[offset + 4] = (byte)(value >> 24);
+    bytes[offset + 3] = (byte)(value >> 32);
+    bytes[offset + 2] = (byte)(value >> 40);
+    bytes[offset + 1] = (byte)(value >> 48);
+    bytes[offset]     = (byte)(value >> 56);
+    return 8;
+  }
+
+  public static int longTo4ByteArray(byte[] bytes, int offset, long value) {
+    bytes[offset + 3] = (byte)value;
+    bytes[offset + 2] = (byte)(value >> 8);
+    bytes[offset + 1] = (byte)(value >> 16);
+    bytes[offset + 0] = (byte)(value >> 24);
+    return 4;
+  }
+
+  public static int byteArrayToShort(byte[] bytes) {
+    return byteArrayToShort(bytes, 0);
+  }
+
+  public static int byteArrayToShort(byte[] bytes, int offset) {
+    return
+        (bytes[offset] & 0xff) << 8 | (bytes[offset + 1] & 0xff);
+  }
+
+  // The SSL patented 3-byte Value.
+  public static int byteArrayToMedium(byte[] bytes, int offset) {
+    return
+        (bytes[offset]     & 0xff) << 16 |
+            (bytes[offset + 1] & 0xff) << 8  |
+            (bytes[offset + 2] & 0xff);
+  }
+
+  public static int byteArrayToInt(byte[] bytes) {
+    return byteArrayToInt(bytes, 0);
+  }
+
+  public static int byteArrayToInt(byte[] bytes, int offset)  {
+    return
+        (bytes[offset]     & 0xff) << 24 |
+            (bytes[offset + 1] & 0xff) << 16 |
+            (bytes[offset + 2] & 0xff) << 8  |
+            (bytes[offset + 3] & 0xff);
+  }
+
+  public static int byteArrayToIntLittleEndian(byte[] bytes, int offset) {
+    return
+        (bytes[offset + 3] & 0xff) << 24 |
+            (bytes[offset + 2] & 0xff) << 16 |
+            (bytes[offset + 1] & 0xff) << 8  |
+            (bytes[offset]     & 0xff);
+  }
+
+  public static long byteArrayToLong(byte[] bytes) {
+    return byteArrayToLong(bytes, 0);
+  }
+
+  public static long byteArray4ToLong(byte[] bytes, int offset) {
+    return
+        ((bytes[offset + 0] & 0xffL) << 24) |
+            ((bytes[offset + 1] & 0xffL) << 16) |
+            ((bytes[offset + 2] & 0xffL) << 8)  |
+            ((bytes[offset + 3] & 0xffL));
+  }
+
+  public static long byteArrayToLong(byte[] bytes, int offset) {
+    return
+        ((bytes[offset]     & 0xffL) << 56) |
+            ((bytes[offset + 1] & 0xffL) << 48) |
+            ((bytes[offset + 2] & 0xffL) << 40) |
+            ((bytes[offset + 3] & 0xffL) << 32) |
+            ((bytes[offset + 4] & 0xffL) << 24) |
+            ((bytes[offset + 5] & 0xffL) << 16) |
+            ((bytes[offset + 6] & 0xffL) << 8)  |
+            ((bytes[offset + 7] & 0xffL));
+  }
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/Hex.java b/src/main/java/org/whispersystems/libaxolotl/util/Hex.java
new file mode 100644
index 00000000..19285464
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/util/Hex.java
@@ -0,0 +1,77 @@
+/**
+ * Copyright (C) 2014 Open Whisper Systems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.util;
+
+import java.io.IOException;
+
+/**
+ * Utility for generating hex dumps.
+ */
+public class Hex {
+
+  private final static char[] HEX_DIGITS = {
+    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
+  };
+
+  public static String toString(byte[] bytes) {
+    return toString(bytes, 0, bytes.length);
+  }
+
+  public static String toString(byte[] bytes, int offset, int length) {
+    StringBuffer buf = new StringBuffer();
+    for (int i = 0; i < length; i++) {
+      appendHexChar(buf, bytes[offset + i]);
+      buf.append(" ");
+    }
+    return buf.toString();
+  }
+
+  public static String toStringCondensed(byte[] bytes) {
+    StringBuffer buf = new StringBuffer();
+    for (int i=0;i<bytes.length;i++) {
+      appendHexChar(buf, bytes[i]);
+    }
+    return buf.toString();
+  }
+
+  public static byte[] fromStringCondensed(String encoded) throws IOException {
+    final char[] data = encoded.toCharArray();
+    final int    len  = data.length;
+
+    if ((len & 0x01) != 0) {
+      throw new IOException("Odd number of characters.");
+    }
+
+    final byte[] out = new byte[len >> 1];
+
+    for (int i = 0, j = 0; j < len; i++) {
+      int f = Character.digit(data[j], 16) << 4;
+      j++;
+      f = f | Character.digit(data[j], 16);
+      j++;
+      out[i] = (byte) (f & 0xFF);
+    }
+
+    return out;
+  }
+
+  private static void appendHexChar(StringBuffer buf, int b) {
+    buf.append(HEX_DIGITS[(b >> 4) & 0xf]);
+    buf.append(HEX_DIGITS[b & 0xf]);
+  }
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/KeyHelper.java b/src/main/java/org/whispersystems/libaxolotl/util/KeyHelper.java
new file mode 100644
index 00000000..96ee6563
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/util/KeyHelper.java
@@ -0,0 +1,143 @@
+package org.whispersystems.libaxolotl.util;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.IdentityKeyPair;
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.ecc.Curve;
+import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libaxolotl.state.PreKeyRecord;
+import org.whispersystems.libaxolotl.state.SignedPreKeyRecord;
+
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * Helper class for generating keys of different types.
+ *
+ * @author Moxie Marlinspike
+ */
+public class KeyHelper {
+
+  private KeyHelper() {}
+
+  /**
+   * Generate an identity key pair.  Clients should only do this once,
+   * at install time.
+   *
+   * @return the generated IdentityKeyPair.
+   */
+  public static IdentityKeyPair generateIdentityKeyPair() {
+    ECKeyPair   keyPair   = Curve.generateKeyPair();
+    IdentityKey publicKey = new IdentityKey(keyPair.getPublicKey());
+    return new IdentityKeyPair(publicKey, keyPair.getPrivateKey());
+  }
+
+  /**
+   * Generate a registration ID.  Clients should only do this once,
+   * at install time.
+   *
+   * @param extendedRange By default (false), the generated registration
+   *                      ID is sized to require the minimal possible protobuf
+   *                      encoding overhead. Specify true if the caller needs
+   *                      the full range of MAX_INT at the cost of slightly
+   *                      higher encoding overhead.
+   * @return the generated registration ID.
+   */
+  public static int generateRegistrationId(boolean extendedRange) {
+    try {
+      SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
+      if (extendedRange) return secureRandom.nextInt(Integer.MAX_VALUE - 1) + 1;
+      else               return secureRandom.nextInt(16380) + 1;
+    } catch (NoSuchAlgorithmException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public static int getRandomSequence(int max) {
+    try {
+      return SecureRandom.getInstance("SHA1PRNG").nextInt(max);
+    } catch (NoSuchAlgorithmException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  /**
+   * Generate a list of PreKeys.  Clients should do this at install time, and
+   * subsequently any time the list of PreKeys stored on the server runs low.
+   * <p>
+   * PreKey IDs are shorts, so they will eventually be repeated.  Clients should
+   * store PreKeys in a circular buffer, so that they are repeated as infrequently
+   * as possible.
+   *
+   * @param start The starting PreKey ID, inclusive.
+   * @param count The number of PreKeys to generate.
+   * @return the list of generated PreKeyRecords.
+   */
+  public static List<PreKeyRecord> generatePreKeys(int start, int count) {
+    List<PreKeyRecord> results = new LinkedList<>();
+
+    start--;
+
+    for (int i=0;i<count;i++) {
+      results.add(new PreKeyRecord(((start + i) % (Medium.MAX_VALUE-1)) + 1, Curve.generateKeyPair()));
+    }
+
+    return results;
+  }
+
+  /**
+   * Generate the last resort PreKey.  Clients should do this only once, at install
+   * time, and durably store it for the length of the install.
+   *
+   * @return the generated last resort PreKeyRecord.
+   */
+  public static PreKeyRecord generateLastResortPreKey() {
+    ECKeyPair keyPair = Curve.generateKeyPair();
+    return new PreKeyRecord(Medium.MAX_VALUE, keyPair);
+  }
+
+  /**
+   * Generate a signed PreKey
+   *
+   * @param identityKeyPair The local client's identity key pair.
+   * @param signedPreKeyId The PreKey id to assign the generated signed PreKey
+   *
+   * @return the generated signed PreKey
+   * @throws InvalidKeyException when the provided identity key is invalid
+   */
+  public static SignedPreKeyRecord generateSignedPreKey(IdentityKeyPair identityKeyPair, int signedPreKeyId)
+      throws InvalidKeyException
+  {
+    ECKeyPair keyPair   = Curve.generateKeyPair();
+    byte[]    signature = Curve.calculateSignature(identityKeyPair.getPrivateKey(), keyPair.getPublicKey().serialize());
+
+    return new SignedPreKeyRecord(signedPreKeyId, System.currentTimeMillis(), keyPair, signature);
+  }
+
+
+  public static ECKeyPair generateSenderSigningKey() {
+    return Curve.generateKeyPair();
+  }
+
+  public static byte[] generateSenderKey() {
+    try {
+      byte[] key = new byte[32];
+      SecureRandom.getInstance("SHA1PRNG").nextBytes(key);
+
+      return key;
+    } catch (NoSuchAlgorithmException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public static int generateSenderKeyId() {
+    try {
+      return SecureRandom.getInstance("SHA1PRNG").nextInt(Integer.MAX_VALUE);
+    } catch (NoSuchAlgorithmException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/Medium.java b/src/main/java/org/whispersystems/libaxolotl/util/Medium.java
new file mode 100644
index 00000000..d18b2d66
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/util/Medium.java
@@ -0,0 +1,5 @@
+package org.whispersystems.libaxolotl.util;
+
+public class Medium {
+  public static int MAX_VALUE = 0xFFFFFF;
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/Pair.java b/src/main/java/org/whispersystems/libaxolotl/util/Pair.java
new file mode 100644
index 00000000..0476d932
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/util/Pair.java
@@ -0,0 +1,51 @@
+/**
+ * Copyright (C) 2014 Open WhisperSystems
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.whispersystems.libaxolotl.util;
+
+public class Pair<T1, T2> {
+  private final T1 v1;
+  private final T2 v2;
+
+  public Pair(T1 v1, T2 v2) {
+    this.v1 = v1;
+    this.v2 = v2;
+  }
+
+  public T1 first(){
+    return v1;
+  }
+
+  public T2 second(){
+    return v2;
+  }
+
+  public boolean equals(Object o) {
+    return o instanceof Pair &&
+        equal(((Pair) o).first(), first()) &&
+        equal(((Pair) o).second(), second());
+  }
+
+  public int hashCode() {
+    return first().hashCode() ^ second().hashCode();
+  }
+
+  private boolean equal(Object first, Object second) {
+    if (first == null && second == null) return true;
+    if (first == null || second == null) return false;
+    return first.equals(second);
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/guava/Absent.java b/src/main/java/org/whispersystems/libaxolotl/util/guava/Absent.java
new file mode 100644
index 00000000..bd06ded9
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/util/guava/Absent.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2011 The Guava Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.whispersystems.libaxolotl.util.guava;
+
+import static org.whispersystems.libaxolotl.util.guava.Preconditions.checkNotNull;
+
+
+
+import java.util.Collections;
+import java.util.Set;
+
+
+/**
+ * Implementation of an {@link Optional} not containing a reference.
+ */
+
+final class Absent extends Optional<Object> {
+  static final Absent INSTANCE = new Absent();
+
+  @Override public boolean isPresent() {
+    return false;
+  }
+
+  @Override public Object get() {
+    throw new IllegalStateException("value is absent");
+  }
+
+  @Override public Object or(Object defaultValue) {
+    return checkNotNull(defaultValue, "use orNull() instead of or(null)");
+  }
+
+  @SuppressWarnings("unchecked") // safe covariant cast
+  @Override public Optional<Object> or(Optional<?> secondChoice) {
+    return (Optional) checkNotNull(secondChoice);
+  }
+
+  @Override public Object or(Supplier<?> supplier) {
+    return checkNotNull(supplier.get(),
+        "use orNull() instead of a Supplier that returns null");
+  }
+
+  @Override public Object orNull() {
+    return null;
+  }
+
+  @Override public Set<Object> asSet() {
+    return Collections.emptySet();
+  }
+
+  @Override
+  public <V> Optional<V> transform(Function<? super Object, V> function) {
+    checkNotNull(function);
+    return Optional.absent();
+  }
+
+  @Override public boolean equals(Object object) {
+    return object == this;
+  }
+
+  @Override public int hashCode() {
+    return 0x598df91c;
+  }
+
+  @Override public String toString() {
+    return "Optional.absent()";
+  }
+
+  private Object readResolve() {
+    return INSTANCE;
+  }
+
+  private static final long serialVersionUID = 0;
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/guava/Function.java b/src/main/java/org/whispersystems/libaxolotl/util/guava/Function.java
new file mode 100644
index 00000000..1ad516c5
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/util/guava/Function.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2007 The Guava Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.whispersystems.libaxolotl.util.guava;
+
+
+
+/**
+ * Determines an output value based on an input value.
+ * 
+ * <p>See the Guava User Guide article on <a href=
+ * "http://code.google.com/p/guava-libraries/wiki/FunctionalExplained">the use of {@code
+ * Function}</a>.
+ * 
+ * @author Kevin Bourrillion
+ * @since 2.0 (imported from Google Collections Library)
+ */
+
+public interface Function<F, T> {
+  /**
+   * Returns the result of applying this function to {@code input}. This method is <i>generally
+   * expected</i>, but not absolutely required, to have the following properties:
+   *
+   * <ul>
+   * <li>Its execution does not cause any observable side effects.
+   * <li>The computation is <i>consistent with equals</i>; that is, {@link Objects#equal
+   *     Objects.equal}{@code (a, b)} implies that {@code Objects.equal(function.apply(a),
+   *     function.apply(b))}.
+   * </ul>
+   *
+   * @throws NullPointerException if {@code input} is null and this function does not accept null
+   *     arguments
+   */
+  T apply(F input);
+
+  /**
+   * Indicates whether another object is equal to this function.
+   *
+   * <p>Most implementations will have no reason to override the behavior of {@link Object#equals}.
+   * However, an implementation may also choose to return {@code true} whenever {@code object} is a
+   * {@link Function} that it considers <i>interchangeable</i> with this one. "Interchangeable"
+   * <i>typically</i> means that {@code Objects.equal(this.apply(f), that.apply(f))} is true for all
+   * {@code f} of type {@code F}. Note that a {@code false} result from this method does not imply
+   * that the functions are known <i>not</i> to be interchangeable.
+   */
+  @Override
+  boolean equals(Object object);
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/guava/Optional.java b/src/main/java/org/whispersystems/libaxolotl/util/guava/Optional.java
new file mode 100644
index 00000000..4f2de832
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/util/guava/Optional.java
@@ -0,0 +1,232 @@
+/*
+ * Copyright (C) 2011 The Guava Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.whispersystems.libaxolotl.util.guava;
+
+import static org.whispersystems.libaxolotl.util.guava.Preconditions.checkNotNull;
+
+import java.io.Serializable;
+import java.util.Iterator;
+import java.util.Set;
+
+
+/**
+ * An immutable object that may contain a non-null reference to another object. Each
+ * instance of this type either contains a non-null reference, or contains nothing (in
+ * which case we say that the reference is "absent"); it is never said to "contain {@code
+ * null}".
+ *
+ * <p>A non-null {@code Optional<T>} reference can be used as a replacement for a nullable
+ * {@code T} reference. It allows you to represent "a {@code T} that must be present" and
+ * a "a {@code T} that might be absent" as two distinct types in your program, which can
+ * aid clarity.
+ *
+ * <p>Some uses of this class include
+ *
+ * <ul>
+ * <li>As a method return type, as an alternative to returning {@code null} to indicate
+ *     that no value was available
+ * <li>To distinguish between "unknown" (for example, not present in a map) and "known to
+ *     have no value" (present in the map, with value {@code Optional.absent()})
+ * <li>To wrap nullable references for storage in a collection that does not support
+ *     {@code null} (though there are
+ *     <a href="http://code.google.com/p/guava-libraries/wiki/LivingWithNullHostileCollections">
+ *     several other approaches to this</a> that should be considered first)
+ * </ul>
+ *
+ * <p>A common alternative to using this class is to find or create a suitable
+ * <a href="http://en.wikipedia.org/wiki/Null_Object_pattern">null object</a> for the
+ * type in question.
+ *
+ * <p>This class is not intended as a direct analogue of any existing "option" or "maybe"
+ * construct from other programming environments, though it may bear some similarities.
+ *
+ * <p>See the Guava User Guide article on <a
+ * href="http://code.google.com/p/guava-libraries/wiki/UsingAndAvoidingNullExplained#Optional">
+ * using {@code Optional}</a>.
+ *
+ * @param <T> the type of instance that can be contained. {@code Optional} is naturally
+ *     covariant on this type, so it is safe to cast an {@code Optional<T>} to {@code
+ *     Optional<S>} for any supertype {@code S} of {@code T}.
+ * @author Kurt Alfred Kluever
+ * @author Kevin Bourrillion
+ * @since 10.0
+ */
+public abstract class Optional<T> implements Serializable {
+  /**
+   * Returns an {@code Optional} instance with no contained reference.
+   */
+  @SuppressWarnings("unchecked")
+  public static <T> Optional<T> absent() {
+    return (Optional<T>) Absent.INSTANCE;
+  }
+
+  /**
+   * Returns an {@code Optional} instance containing the given non-null reference.
+   */
+  public static <T> Optional<T> of(T reference) {
+    return new Present<T>(checkNotNull(reference));
+  }
+
+  /**
+   * If {@code nullableReference} is non-null, returns an {@code Optional} instance containing that
+   * reference; otherwise returns {@link Optional#absent}.
+   */
+  public static <T> Optional<T> fromNullable(T nullableReference) {
+    return (nullableReference == null)
+        ? Optional.<T>absent()
+        : new Present<T>(nullableReference);
+  }
+
+  Optional() {}
+
+  /**
+   * Returns {@code true} if this holder contains a (non-null) instance.
+   */
+  public abstract boolean isPresent();
+
+  /**
+   * Returns the contained instance, which must be present. If the instance might be
+   * absent, use {@link #or(Object)} or {@link #orNull} instead.
+   *
+   * @throws IllegalStateException if the instance is absent ({@link #isPresent} returns
+   *     {@code false})
+   */
+  public abstract T get();
+
+  /**
+   * Returns the contained instance if it is present; {@code defaultValue} otherwise. If
+   * no default value should be required because the instance is known to be present, use
+   * {@link #get()} instead. For a default value of {@code null}, use {@link #orNull}.
+   *
+   * <p>Note about generics: The signature {@code public T or(T defaultValue)} is overly
+   * restrictive. However, the ideal signature, {@code public <S super T> S or(S)}, is not legal
+   * Java. As a result, some sensible operations involving subtypes are compile errors:
+   * <pre>   {@code
+   *
+   *   Optional<Integer> optionalInt = getSomeOptionalInt();
+   *   Number value = optionalInt.or(0.5); // error
+   *
+   *   FluentIterable<? extends Number> numbers = getSomeNumbers();
+   *   Optional<? extends Number> first = numbers.first();
+   *   Number value = first.or(0.5); // error}</pre>
+   *
+   * As a workaround, it is always safe to cast an {@code Optional<? extends T>} to {@code
+   * Optional<T>}. Casting either of the above example {@code Optional} instances to {@code
+   * Optional<Number>} (where {@code Number} is the desired output type) solves the problem:
+   * <pre>   {@code
+   *
+   *   Optional<Number> optionalInt = (Optional) getSomeOptionalInt();
+   *   Number value = optionalInt.or(0.5); // fine
+   *
+   *   FluentIterable<? extends Number> numbers = getSomeNumbers();
+   *   Optional<Number> first = (Optional) numbers.first();
+   *   Number value = first.or(0.5); // fine}</pre>
+   */
+  public abstract T or(T defaultValue);
+
+  /**
+   * Returns this {@code Optional} if it has a value present; {@code secondChoice}
+   * otherwise.
+   */
+  public abstract Optional<T> or(Optional<? extends T> secondChoice);
+
+  /**
+   * Returns the contained instance if it is present; {@code supplier.get()} otherwise. If the
+   * supplier returns {@code null}, a {@link NullPointerException} is thrown.
+   *
+   * @throws NullPointerException if the supplier returns {@code null}
+   */
+  public abstract T or(Supplier<? extends T> supplier);
+
+  /**
+   * Returns the contained instance if it is present; {@code null} otherwise. If the
+   * instance is known to be present, use {@link #get()} instead.
+   */
+  public abstract T orNull();
+
+  /**
+   * Returns an immutable singleton {@link Set} whose only element is the contained instance
+   * if it is present; an empty immutable {@link Set} otherwise.
+   *
+   * @since 11.0
+   */
+  public abstract Set<T> asSet();
+
+  /**
+   * If the instance is present, it is transformed with the given {@link Function}; otherwise,
+   * {@link Optional#absent} is returned. If the function returns {@code null}, a
+   * {@link NullPointerException} is thrown.
+   *
+   * @throws NullPointerException if the function returns {@code null}
+   *
+   * @since 12.0
+   */
+ 
+  public abstract <V> Optional<V> transform(Function<? super T, V> function);
+
+  /**
+   * Returns {@code true} if {@code object} is an {@code Optional} instance, and either
+   * the contained references are {@linkplain Object#equals equal} to each other or both
+   * are absent. Note that {@code Optional} instances of differing parameterized types can
+   * be equal.
+   */
+  @Override public abstract boolean equals(Object object);
+
+  /**
+   * Returns a hash code for this instance.
+   */
+  @Override public abstract int hashCode();
+
+  /**
+   * Returns a string representation for this instance. The form of this string
+   * representation is unspecified.
+   */
+  @Override public abstract String toString();
+
+  /**
+   * Returns the value of each present instance from the supplied {@code optionals}, in order,
+   * skipping over occurrences of {@link Optional#absent}. Iterators are unmodifiable and are
+   * evaluated lazily.
+   *
+   * @since 11.0 (generics widened in 13.0)
+   */
+
+//  public static <T> Iterable<T> presentInstances(
+//      final Iterable<? extends Optional<? extends T>> optionals) {
+//    checkNotNull(optionals);
+//    return new Iterable<T>() {
+//      @Override public Iterator<T> iterator() {
+//        return new AbstractIterator<T>() {
+//          private final Iterator<? extends Optional<? extends T>> iterator =
+//              checkNotNull(optionals.iterator());
+//
+//          @Override protected T computeNext() {
+//            while (iterator.hasNext()) {
+//              Optional<? extends T> optional = iterator.next();
+//              if (optional.isPresent()) {
+//                return optional.get();
+//              }
+//            }
+//            return endOfData();
+//          }
+//        };
+//      };
+//    };
+//  }
+
+  private static final long serialVersionUID = 0;
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/guava/Preconditions.java b/src/main/java/org/whispersystems/libaxolotl/util/guava/Preconditions.java
new file mode 100644
index 00000000..ce253c65
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/util/guava/Preconditions.java
@@ -0,0 +1,447 @@
+/*
+ * Copyright (C) 2007 The Guava Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.whispersystems.libaxolotl.util.guava;
+
+
+import java.util.NoSuchElementException;
+
+
+
+/**
+ * Simple static methods to be called at the start of your own methods to verify
+ * correct arguments and state. This allows constructs such as
+ * <pre>
+ *     if (count <= 0) {
+ *       throw new IllegalArgumentException("must be positive: " + count);
+ *     }</pre>
+ *
+ * to be replaced with the more compact
+ * <pre>
+ *     checkArgument(count > 0, "must be positive: %s", count);</pre>
+ *
+ * Note that the sense of the expression is inverted; with {@code Preconditions}
+ * you declare what you expect to be <i>true</i>, just as you do with an
+ * <a href="http://java.sun.com/j2se/1.5.0/docs/guide/language/assert.html">
+ * {@code assert}</a> or a JUnit {@code assertTrue} call.
+ *
+ * <p><b>Warning:</b> only the {@code "%s"} specifier is recognized as a
+ * placeholder in these messages, not the full range of {@link
+ * String#format(String, Object[])} specifiers.
+ *
+ * <p>Take care not to confuse precondition checking with other similar types
+ * of checks! Precondition exceptions -- including those provided here, but also
+ * {@link IndexOutOfBoundsException}, {@link NoSuchElementException}, {@link
+ * UnsupportedOperationException} and others -- are used to signal that the
+ * <i>calling method</i> has made an error. This tells the caller that it should
+ * not have invoked the method when it did, with the arguments it did, or
+ * perhaps ever. Postcondition or other invariant failures should not throw
+ * these types of exceptions.
+ *
+ * <p>See the Guava User Guide on <a href=
+ * "http://code.google.com/p/guava-libraries/wiki/PreconditionsExplained">
+ * using {@code Preconditions}</a>.
+ *
+ * @author Kevin Bourrillion
+ * @since 2.0 (imported from Google Collections Library)
+ */
+
+public final class Preconditions {
+  private Preconditions() {}
+
+  /**
+   * Ensures the truth of an expression involving one or more parameters to the
+   * calling method.
+   *
+   * @param expression a boolean expression
+   * @throws IllegalArgumentException if {@code expression} is false
+   */
+  public static void checkArgument(boolean expression) {
+    if (!expression) {
+      throw new IllegalArgumentException();
+    }
+  }
+
+  /**
+   * Ensures the truth of an expression involving one or more parameters to the
+   * calling method.
+   *
+   * @param expression a boolean expression
+   * @param errorMessage the exception message to use if the check fails; will
+   *     be converted to a string using {@link String#valueOf(Object)}
+   * @throws IllegalArgumentException if {@code expression} is false
+   */
+  public static void checkArgument(
+      boolean expression, Object errorMessage) {
+    if (!expression) {
+      throw new IllegalArgumentException(String.valueOf(errorMessage));
+    }
+  }
+
+  /**
+   * Ensures the truth of an expression involving one or more parameters to the
+   * calling method.
+   *
+   * @param expression a boolean expression
+   * @param errorMessageTemplate a template for the exception message should the
+   *     check fail. The message is formed by replacing each {@code %s}
+   *     placeholder in the template with an argument. These are matched by
+   *     position - the first {@code %s} gets {@code errorMessageArgs[0]}, etc.
+   *     Unmatched arguments will be appended to the formatted message in square
+   *     braces. Unmatched placeholders will be left as-is.
+   * @param errorMessageArgs the arguments to be substituted into the message
+   *     template. Arguments are converted to strings using
+   *     {@link String#valueOf(Object)}.
+   * @throws IllegalArgumentException if {@code expression} is false
+   * @throws NullPointerException if the check fails and either {@code
+   *     errorMessageTemplate} or {@code errorMessageArgs} is null (don't let
+   *     this happen)
+   */
+  public static void checkArgument(boolean expression,
+      String errorMessageTemplate,
+      Object... errorMessageArgs) {
+    if (!expression) {
+      throw new IllegalArgumentException(
+          format(errorMessageTemplate, errorMessageArgs));
+    }
+  }
+
+  /**
+   * Ensures the truth of an expression involving the state of the calling
+   * instance, but not involving any parameters to the calling method.
+   *
+   * @param expression a boolean expression
+   * @throws IllegalStateException if {@code expression} is false
+   */
+  public static void checkState(boolean expression) {
+    if (!expression) {
+      throw new IllegalStateException();
+    }
+  }
+
+  /**
+   * Ensures the truth of an expression involving the state of the calling
+   * instance, but not involving any parameters to the calling method.
+   *
+   * @param expression a boolean expression
+   * @param errorMessage the exception message to use if the check fails; will
+   *     be converted to a string using {@link String#valueOf(Object)}
+   * @throws IllegalStateException if {@code expression} is false
+   */
+  public static void checkState(
+      boolean expression, Object errorMessage) {
+    if (!expression) {
+      throw new IllegalStateException(String.valueOf(errorMessage));
+    }
+  }
+
+  /**
+   * Ensures the truth of an expression involving the state of the calling
+   * instance, but not involving any parameters to the calling method.
+   *
+   * @param expression a boolean expression
+   * @param errorMessageTemplate a template for the exception message should the
+   *     check fail. The message is formed by replacing each {@code %s}
+   *     placeholder in the template with an argument. These are matched by
+   *     position - the first {@code %s} gets {@code errorMessageArgs[0]}, etc.
+   *     Unmatched arguments will be appended to the formatted message in square
+   *     braces. Unmatched placeholders will be left as-is.
+   * @param errorMessageArgs the arguments to be substituted into the message
+   *     template. Arguments are converted to strings using
+   *     {@link String#valueOf(Object)}.
+   * @throws IllegalStateException if {@code expression} is false
+   * @throws NullPointerException if the check fails and either {@code
+   *     errorMessageTemplate} or {@code errorMessageArgs} is null (don't let
+   *     this happen)
+   */
+  public static void checkState(boolean expression,
+      String errorMessageTemplate,
+      Object... errorMessageArgs) {
+    if (!expression) {
+      throw new IllegalStateException(
+          format(errorMessageTemplate, errorMessageArgs));
+    }
+  }
+
+  /**
+   * Ensures that an object reference passed as a parameter to the calling
+   * method is not null.
+   *
+   * @param reference an object reference
+   * @return the non-null reference that was validated
+   * @throws NullPointerException if {@code reference} is null
+   */
+  public static <T> T checkNotNull(T reference) {
+    if (reference == null) {
+      throw new NullPointerException();
+    }
+    return reference;
+  }
+
+  /**
+   * Ensures that an object reference passed as a parameter to the calling
+   * method is not null.
+   *
+   * @param reference an object reference
+   * @param errorMessage the exception message to use if the check fails; will
+   *     be converted to a string using {@link String#valueOf(Object)}
+   * @return the non-null reference that was validated
+   * @throws NullPointerException if {@code reference} is null
+   */
+  public static <T> T checkNotNull(T reference, Object errorMessage) {
+    if (reference == null) {
+      throw new NullPointerException(String.valueOf(errorMessage));
+    }
+    return reference;
+  }
+
+  /**
+   * Ensures that an object reference passed as a parameter to the calling
+   * method is not null.
+   *
+   * @param reference an object reference
+   * @param errorMessageTemplate a template for the exception message should the
+   *     check fail. The message is formed by replacing each {@code %s}
+   *     placeholder in the template with an argument. These are matched by
+   *     position - the first {@code %s} gets {@code errorMessageArgs[0]}, etc.
+   *     Unmatched arguments will be appended to the formatted message in square
+   *     braces. Unmatched placeholders will be left as-is.
+   * @param errorMessageArgs the arguments to be substituted into the message
+   *     template. Arguments are converted to strings using
+   *     {@link String#valueOf(Object)}.
+   * @return the non-null reference that was validated
+   * @throws NullPointerException if {@code reference} is null
+   */
+  public static <T> T checkNotNull(T reference,
+      String errorMessageTemplate,
+      Object... errorMessageArgs) {
+    if (reference == null) {
+      // If either of these parameters is null, the right thing happens anyway
+      throw new NullPointerException(
+          format(errorMessageTemplate, errorMessageArgs));
+    }
+    return reference;
+  }
+
+  /*
+   * All recent hotspots (as of 2009) *really* like to have the natural code
+   *
+   * if (guardExpression) {
+   *    throw new BadException(messageExpression);
+   * }
+   *
+   * refactored so that messageExpression is moved to a separate
+   * String-returning method.
+   *
+   * if (guardExpression) {
+   *    throw new BadException(badMsg(...));
+   * }
+   *
+   * The alternative natural refactorings into void or Exception-returning
+   * methods are much slower.  This is a big deal - we're talking factors of
+   * 2-8 in microbenchmarks, not just 10-20%.  (This is a hotspot optimizer
+   * bug, which should be fixed, but that's a separate, big project).
+   *
+   * The coding pattern above is heavily used in java.util, e.g. in ArrayList.
+   * There is a RangeCheckMicroBenchmark in the JDK that was used to test this.
+   *
+   * But the methods in this class want to throw different exceptions,
+   * depending on the args, so it appears that this pattern is not directly
+   * applicable.  But we can use the ridiculous, devious trick of throwing an
+   * exception in the middle of the construction of another exception.
+   * Hotspot is fine with that.
+   */
+
+  /**
+   * Ensures that {@code index} specifies a valid <i>element</i> in an array,
+   * list or string of size {@code size}. An element index may range from zero,
+   * inclusive, to {@code size}, exclusive.
+   *
+   * @param index a user-supplied index identifying an element of an array, list
+   *     or string
+   * @param size the size of that array, list or string
+   * @return the value of {@code index}
+   * @throws IndexOutOfBoundsException if {@code index} is negative or is not
+   *     less than {@code size}
+   * @throws IllegalArgumentException if {@code size} is negative
+   */
+  public static int checkElementIndex(int index, int size) {
+    return checkElementIndex(index, size, "index");
+  }
+
+  /**
+   * Ensures that {@code index} specifies a valid <i>element</i> in an array,
+   * list or string of size {@code size}. An element index may range from zero,
+   * inclusive, to {@code size}, exclusive.
+   *
+   * @param index a user-supplied index identifying an element of an array, list
+   *     or string
+   * @param size the size of that array, list or string
+   * @param desc the text to use to describe this index in an error message
+   * @return the value of {@code index}
+   * @throws IndexOutOfBoundsException if {@code index} is negative or is not
+   *     less than {@code size}
+   * @throws IllegalArgumentException if {@code size} is negative
+   */
+  public static int checkElementIndex(
+      int index, int size, String desc) {
+    // Carefully optimized for execution by hotspot (explanatory comment above)
+    if (index < 0 || index >= size) {
+      throw new IndexOutOfBoundsException(badElementIndex(index, size, desc));
+    }
+    return index;
+  }
+
+  private static String badElementIndex(int index, int size, String desc) {
+    if (index < 0) {
+      return format("%s (%s) must not be negative", desc, index);
+    } else if (size < 0) {
+      throw new IllegalArgumentException("negative size: " + size);
+    } else { // index >= size
+      return format("%s (%s) must be less than size (%s)", desc, index, size);
+    }
+  }
+
+  /**
+   * Ensures that {@code index} specifies a valid <i>position</i> in an array,
+   * list or string of size {@code size}. A position index may range from zero
+   * to {@code size}, inclusive.
+   *
+   * @param index a user-supplied index identifying a position in an array, list
+   *     or string
+   * @param size the size of that array, list or string
+   * @return the value of {@code index}
+   * @throws IndexOutOfBoundsException if {@code index} is negative or is
+   *     greater than {@code size}
+   * @throws IllegalArgumentException if {@code size} is negative
+   */
+  public static int checkPositionIndex(int index, int size) {
+    return checkPositionIndex(index, size, "index");
+  }
+
+  /**
+   * Ensures that {@code index} specifies a valid <i>position</i> in an array,
+   * list or string of size {@code size}. A position index may range from zero
+   * to {@code size}, inclusive.
+   *
+   * @param index a user-supplied index identifying a position in an array, list
+   *     or string
+   * @param size the size of that array, list or string
+   * @param desc the text to use to describe this index in an error message
+   * @return the value of {@code index}
+   * @throws IndexOutOfBoundsException if {@code index} is negative or is
+   *     greater than {@code size}
+   * @throws IllegalArgumentException if {@code size} is negative
+   */
+  public static int checkPositionIndex(
+      int index, int size, String desc) {
+    // Carefully optimized for execution by hotspot (explanatory comment above)
+    if (index < 0 || index > size) {
+      throw new IndexOutOfBoundsException(badPositionIndex(index, size, desc));
+    }
+    return index;
+  }
+
+  private static String badPositionIndex(int index, int size, String desc) {
+    if (index < 0) {
+      return format("%s (%s) must not be negative", desc, index);
+    } else if (size < 0) {
+      throw new IllegalArgumentException("negative size: " + size);
+    } else { // index > size
+      return format("%s (%s) must not be greater than size (%s)",
+                    desc, index, size);
+    }
+  }
+
+  /**
+   * Ensures that {@code start} and {@code end} specify a valid <i>positions</i>
+   * in an array, list or string of size {@code size}, and are in order. A
+   * position index may range from zero to {@code size}, inclusive.
+   *
+   * @param start a user-supplied index identifying a starting position in an
+   *     array, list or string
+   * @param end a user-supplied index identifying a ending position in an array,
+   *     list or string
+   * @param size the size of that array, list or string
+   * @throws IndexOutOfBoundsException if either index is negative or is
+   *     greater than {@code size}, or if {@code end} is less than {@code start}
+   * @throws IllegalArgumentException if {@code size} is negative
+   */
+  public static void checkPositionIndexes(int start, int end, int size) {
+    // Carefully optimized for execution by hotspot (explanatory comment above)
+    if (start < 0 || end < start || end > size) {
+      throw new IndexOutOfBoundsException(badPositionIndexes(start, end, size));
+    }
+  }
+
+  private static String badPositionIndexes(int start, int end, int size) {
+    if (start < 0 || start > size) {
+      return badPositionIndex(start, size, "start index");
+    }
+    if (end < 0 || end > size) {
+      return badPositionIndex(end, size, "end index");
+    }
+    // end < start
+    return format("end index (%s) must not be less than start index (%s)",
+                  end, start);
+  }
+
+  /**
+   * Substitutes each {@code %s} in {@code template} with an argument. These
+   * are matched by position - the first {@code %s} gets {@code args[0]}, etc.
+   * If there are more arguments than placeholders, the unmatched arguments will
+   * be appended to the end of the formatted message in square braces.
+   *
+   * @param template a non-null string containing 0 or more {@code %s}
+   *     placeholders.
+   * @param args the arguments to be substituted into the message
+   *     template. Arguments are converted to strings using
+   *     {@link String#valueOf(Object)}. Arguments can be null.
+   */
+   static String format(String template,
+      Object... args) {
+    template = String.valueOf(template); // null -> "null"
+
+    // start substituting the arguments into the '%s' placeholders
+    StringBuilder builder = new StringBuilder(
+        template.length() + 16 * args.length);
+    int templateStart = 0;
+    int i = 0;
+    while (i < args.length) {
+      int placeholderStart = template.indexOf("%s", templateStart);
+      if (placeholderStart == -1) {
+        break;
+      }
+      builder.append(template.substring(templateStart, placeholderStart));
+      builder.append(args[i++]);
+      templateStart = placeholderStart + 2;
+    }
+    builder.append(template.substring(templateStart));
+
+    // if we run out of placeholders, append the extra args in square braces
+    if (i < args.length) {
+      builder.append(" [");
+      builder.append(args[i++]);
+      while (i < args.length) {
+        builder.append(", ");
+        builder.append(args[i++]);
+      }
+      builder.append(']');
+    }
+
+    return builder.toString();
+  }
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/guava/Present.java b/src/main/java/org/whispersystems/libaxolotl/util/guava/Present.java
new file mode 100644
index 00000000..630570ff
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/util/guava/Present.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2011 The Guava Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.whispersystems.libaxolotl.util.guava;
+
+import static org.whispersystems.libaxolotl.util.guava.Preconditions.checkNotNull;
+
+import java.util.Collections;
+import java.util.Set;
+
+/**
+ * Implementation of an {@link Optional} containing a reference.
+ */
+
+final class Present<T> extends Optional<T> {
+  private final T reference;
+
+  Present(T reference) {
+    this.reference = reference;
+  }
+
+  @Override public boolean isPresent() {
+    return true;
+  }
+
+  @Override public T get() {
+    return reference;
+  }
+
+  @Override public T or(T defaultValue) {
+    checkNotNull(defaultValue, "use orNull() instead of or(null)");
+    return reference;
+  }
+
+  @Override public Optional<T> or(Optional<? extends T> secondChoice) {
+    checkNotNull(secondChoice);
+    return this;
+  }
+
+  @Override public T or(Supplier<? extends T> supplier) {
+    checkNotNull(supplier);
+    return reference;
+  }
+
+  @Override public T orNull() {
+    return reference;
+  }
+
+  @Override public Set<T> asSet() {
+    return Collections.singleton(reference);
+  }
+  
+  @Override public <V> Optional<V> transform(Function<? super T, V> function) {
+    return new Present<V>(checkNotNull(function.apply(reference),
+        "Transformation function cannot return null."));
+  }
+
+  @Override public boolean equals(Object object) {
+    if (object instanceof Present) {
+      Present<?> other = (Present<?>) object;
+      return reference.equals(other.reference);
+    }
+    return false;
+  }
+
+  @Override public int hashCode() {
+    return 0x598df91c + reference.hashCode();
+  }
+
+  @Override public String toString() {
+    return "Optional.of(" + reference + ")";
+  }
+
+  private static final long serialVersionUID = 0;
+}
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/guava/Supplier.java b/src/main/java/org/whispersystems/libaxolotl/util/guava/Supplier.java
new file mode 100644
index 00000000..ba880707
--- /dev/null
+++ b/src/main/java/org/whispersystems/libaxolotl/util/guava/Supplier.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2007 The Guava Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.whispersystems.libaxolotl.util.guava;
+
+
+/**
+ * A class that can supply objects of a single type.  Semantically, this could
+ * be a factory, generator, builder, closure, or something else entirely. No
+ * guarantees are implied by this interface.
+ *
+ * @author Harry Heymann
+ * @since 2.0 (imported from Google Collections Library)
+ */
+public interface Supplier<T> {
+  /**
+   * Retrieves an instance of the appropriate type. The returned object may or
+   * may not be a new instance, depending on the implementation.
+   *
+   * @return an instance of the appropriate type
+   */
+  T get();
+}