private byte[] decrypt(SessionState sessionState, WhisperMessage ciphertextMessage) { if (!sessionState.hasSenderChain()) { throw new InvalidMessageException("Uninitialized session!"); } if (ciphertextMessage.getMessageVersion() != sessionState.getSessionVersion()) { throw new InvalidMessageException($"Message version {ciphertextMessage.getMessageVersion()}, but session version {sessionState.getSessionVersion()}"); } uint messageVersion = ciphertextMessage.getMessageVersion(); ECPublicKey theirEphemeral = ciphertextMessage.getSenderRatchetKey(); uint 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 void testRatchetingSessionAsAlice() { byte[] bobPublic = { 0x05, 0x2c, 0xb4, 0x97, 0x76, 0xb8, 0x77, 0x02, 0x05, 0x74, 0x5a, 0x3a, 0x6e, 0x24, 0xf5, 0x79, 0xcd, 0xb4, 0xba, 0x7a, 0x89, 0x04, 0x10, 0x05, 0x92, 0x8e, 0xbb, 0xad, 0xc9, 0xc0, 0x5a, 0xd4, 0x58 }; byte[] bobIdentityPublic = { 0x05, 0xf1, 0xf4, 0x38, 0x74, 0xf6, 0x96, 0x69, 0x56, 0xc2, 0xdd, 0x47, 0x3f, 0x8f, 0xa1, 0x5a, 0xde, 0xb7, 0x1d, 0x1c, 0xb9, 0x91, 0xb2, 0x34, 0x16, 0x92, 0x32, 0x4c, 0xef, 0xb1, 0xc5, 0xe6, 0x26 }; byte[] aliceBasePublic = { 0x05, 0x47, 0x2d, 0x1f, 0xb1, 0xa9, 0x86, 0x2c, 0x3a, 0xf6, 0xbe, 0xac, 0xa8, 0x92, 0x02, 0x77, 0xe2, 0xb2, 0x6f, 0x4a, 0x79, 0x21, 0x3e, 0xc7, 0xc9, 0x06, 0xae, 0xb3, 0x5e, 0x03, 0xcf, 0x89, 0x50 }; byte[] aliceBasePrivate = { 0x11, 0xae, 0x7c, 0x64, 0xd1, 0xe6, 0x1c, 0xd5, 0x96, 0xb7, 0x6a, 0x0d, 0xb5, 0x01, 0x26, 0x73, 0x39, 0x1c, 0xae, 0x66, 0xed, 0xbf, 0xcf, 0x07, 0x3b, 0x4d, 0xa8, 0x05, 0x16, 0xa4, 0x74, 0x49 }; byte[] aliceEphemeralPublic = { 0x05, 0x6c, 0x3e, 0x0d, 0x1f, 0x52, 0x02, 0x83, 0xef, 0xcc, 0x55, 0xfc, 0xa5, 0xe6, 0x70, 0x75, 0xb9, 0x04, 0x00, 0x7f, 0x18, 0x81, 0xd1, 0x51, 0xaf, 0x76, 0xdf, 0x18, 0xc5, 0x1d, 0x29, 0xd3, 0x4b }; byte[] aliceEphemeralPrivate = { 0xd1, 0xba, 0x38, 0xce, 0xa9, 0x17, 0x43, 0xd3, 0x39, 0x39, 0xc3, 0x3c, 0x84, 0x98, 0x65, 0x09, 0x28, 0x01, 0x61, 0xb8, 0xb6, 0x0f, 0xc7, 0x87, 0x0c, 0x59, 0x9c, 0x1d, 0x46, 0x20, 0x12, 0x48 }; byte[] aliceIdentityPublic = { 0x05, 0xb4, 0xa8, 0x45, 0x56, 0x60, 0xad, 0xa6, 0x5b, 0x40, 0x10, 0x07, 0xf6, 0x15, 0xe6, 0x54, 0x04, 0x17, 0x46, 0x43, 0x2e, 0x33, 0x39, 0xc6, 0x87, 0x51, 0x49, 0xbc, 0xee, 0xfc, 0xb4, 0x2b, 0x4a }; byte[] aliceIdentityPrivate = { 0x90, 0x40, 0xf0, 0xd4, 0xe0, 0x9c, 0xf3, 0x8f, 0x6d, 0xc7, 0xc1, 0x37, 0x79, 0xc9, 0x08, 0xc0, 0x15, 0xa1, 0xda, 0x4f, 0xa7, 0x87, 0x37, 0xa0, 0x80, 0xeb, 0x0a, 0x6f, 0x4f, 0x5f, 0x8f, 0x58 }; byte[] receiverChain = { 0xd2, 0x2f, 0xd5, 0x6d, 0x3f, 0xec, 0x81, 0x9c, 0xf4, 0xc3, 0xd5, 0x0c, 0x56, 0xed, 0xfb, 0x1c, 0x28, 0x0a, 0x1b, 0x31, 0x96, 0x45, 0x37, 0xf1, 0xd1, 0x61, 0xe1, 0xc9, 0x31, 0x48, 0xe3, 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(May<ECPublicKey>.NoValue) .create(); RatchetingSession.initializeSession(session, 2, parameters); Assert.AreEqual(session.getLocalIdentityKey(), aliceIdentityKey.getPublicKey()); Assert.AreEqual(session.getRemoteIdentityKey(), bobIdentityKey); CollectionAssert.AreEqual(session.getReceiverChainKey(bobEphemeralPublicKey).getKey(), receiverChain); }