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);
}