1 files changed, 196 insertions, 0 deletions
diff --git a/src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlSession.java b/src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlSession.java
new file mode 100644
index 00000000..c4053854
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlSession.java
@@ -0,0 +1,196 @@
+package eu.siacs.conversations.crypto.axolotl;
+
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.util.Log;
+
+import org.whispersystems.libaxolotl.AxolotlAddress;
+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.SessionCipher;
+import org.whispersystems.libaxolotl.UntrustedIdentityException;
+import org.whispersystems.libaxolotl.protocol.CiphertextMessage;
+import org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage;
+import org.whispersystems.libaxolotl.protocol.WhisperMessage;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import eu.siacs.conversations.Config;
+import eu.siacs.conversations.entities.Account;
+
+public class XmppAxolotlSession {
+	private final SessionCipher cipher;
+	private final SQLiteAxolotlStore sqLiteAxolotlStore;
+	private final AxolotlAddress remoteAddress;
+	private final Account account;
+	private String fingerprint = null;
+	private Integer preKeyId = null;
+	private boolean fresh = true;
+
+	public enum Trust {
+		UNDECIDED(0),
+		TRUSTED(1),
+		UNTRUSTED(2),
+		COMPROMISED(3),
+		INACTIVE_TRUSTED(4),
+		INACTIVE_UNDECIDED(5),
+		INACTIVE_UNTRUSTED(6);
+
+		private static final Map<Integer, Trust> trustsByValue = new HashMap<>();
+
+		static {
+			for (Trust trust : Trust.values()) {
+				trustsByValue.put(trust.getCode(), trust);
+			}
+		}
+
+		private final int code;
+
+		Trust(int code) {
+			this.code = code;
+		}
+
+		public int getCode() {
+			return this.code;
+		}
+
+		public String toString() {
+			switch (this) {
+				case UNDECIDED:
+					return "Trust undecided " + getCode();
+				case TRUSTED:
+					return "Trusted " + getCode();
+				case COMPROMISED:
+					return "Compromised " + getCode();
+				case INACTIVE_TRUSTED:
+					return "Inactive (Trusted)" + getCode();
+				case INACTIVE_UNDECIDED:
+					return "Inactive (Undecided)" + getCode();
+				case INACTIVE_UNTRUSTED:
+					return "Inactive (Untrusted)" + getCode();
+				case UNTRUSTED:
+				default:
+					return "Untrusted " + getCode();
+			}
+		}
+
+		public static Trust fromBoolean(Boolean trusted) {
+			return trusted ? TRUSTED : UNTRUSTED;
+		}
+
+		public static Trust fromCode(int code) {
+			return trustsByValue.get(code);
+		}
+	}
+
+	public XmppAxolotlSession(Account account, SQLiteAxolotlStore store, AxolotlAddress remoteAddress, String fingerprint) {
+		this(account, store, remoteAddress);
+		this.fingerprint = fingerprint;
+	}
+
+	public XmppAxolotlSession(Account account, SQLiteAxolotlStore store, AxolotlAddress remoteAddress) {
+		this.cipher = new SessionCipher(store, remoteAddress);
+		this.remoteAddress = remoteAddress;
+		this.sqLiteAxolotlStore = store;
+		this.account = account;
+	}
+
+	public Integer getPreKeyId() {
+		return preKeyId;
+	}
+
+	public void resetPreKeyId() {
+
+		preKeyId = null;
+	}
+
+	public String getFingerprint() {
+		return fingerprint;
+	}
+
+	public AxolotlAddress getRemoteAddress() {
+		return remoteAddress;
+	}
+
+	public boolean isFresh() {
+		return fresh;
+	}
+
+	public void setNotFresh() {
+		this.fresh = false;
+	}
+
+	protected void setTrust(Trust trust) {
+		sqLiteAxolotlStore.setFingerprintTrust(fingerprint, trust);
+	}
+
+	protected Trust getTrust() {
+		Trust trust = sqLiteAxolotlStore.getFingerprintTrust(fingerprint);
+		return (trust == null) ? Trust.UNDECIDED : trust;
+	}
+
+	@Nullable
+	public byte[] processReceiving(byte[] encryptedKey) {
+		byte[] plaintext = null;
+		Trust trust = getTrust();
+		switch (trust) {
+			case INACTIVE_TRUSTED:
+			case UNDECIDED:
+			case UNTRUSTED:
+			case TRUSTED:
+				try {
+					try {
+						PreKeyWhisperMessage message = new PreKeyWhisperMessage(encryptedKey);
+						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "PreKeyWhisperMessage received, new session ID:" + message.getSignedPreKeyId() + "/" + message.getPreKeyId());
+						String fingerprint = message.getIdentityKey().getFingerprint().replaceAll("\\s", "");
+						if (this.fingerprint != null && !this.fingerprint.equals(fingerprint)) {
+							Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Had session with fingerprint " + this.fingerprint + ", received message with fingerprint " + fingerprint);
+						} else {
+							this.fingerprint = fingerprint;
+							plaintext = cipher.decrypt(message);
+							if (message.getPreKeyId().isPresent()) {
+								preKeyId = message.getPreKeyId().get();
+							}
+						}
+					} catch (InvalidMessageException | InvalidVersionException e) {
+						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "WhisperMessage received");
+						WhisperMessage message = new WhisperMessage(encryptedKey);
+						plaintext = cipher.decrypt(message);
+					} catch (InvalidKeyException | InvalidKeyIdException | UntrustedIdentityException e) {
+						Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Error decrypting axolotl header, " + e.getClass().getName() + ": " + e.getMessage());
+					}
+				} catch (LegacyMessageException | InvalidMessageException | DuplicateMessageException | NoSessionException e) {
+					Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Error decrypting axolotl header, " + e.getClass().getName() + ": " + e.getMessage());
+				}
+
+				if (plaintext != null && trust == Trust.INACTIVE_TRUSTED) {
+					setTrust(Trust.TRUSTED);
+				}
+
+				break;
+
+			case COMPROMISED:
+			default:
+				// ignore
+				break;
+		}
+		return plaintext;
+	}
+
+	@Nullable
+	public byte[] processSending(@NonNull byte[] outgoingMessage) {
+		Trust trust = getTrust();
+		if (trust == Trust.TRUSTED) {
+			CiphertextMessage ciphertextMessage = cipher.encrypt(outgoingMessage);
+			return ciphertextMessage.serialize();
+		} else {
+			return null;
+		}
+	}
+}