Break out into separate repo.

7 files changed, 370 insertions, 0 deletions

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();
+}