public void Test_OmemoBundleInformation()
{
IdentityKeyPairModel bobIdentKey = KeyHelper.GenerateIdentityKeyPair();
List <PreKeyModel> bobPreKeys = KeyHelper.GeneratePreKeys(0, 100);
SignedPreKeyModel bobSignedPreKey = KeyHelper.GenerateSignedPreKey(0, bobIdentKey.privKey);
Bundle bobBundle = new Bundle()
{
identityKey = bobIdentKey.pubKey,
preKeys = bobPreKeys.Select(key => new PreKeyModel(null, key.pubKey, key.keyId)).ToList(),
preKeySignature = bobSignedPreKey.signature,
signedPreKey = bobSignedPreKey.preKey.pubKey,
signedPreKeyId = bobSignedPreKey.preKey.keyId
};
string bundleInfo = GetBobsBundleInfoMsg(bobBundle);
MessageParser2 parser = new MessageParser2();
List <AbstractMessage> messages = parser.parseMessages(ref bundleInfo);
// Check if message parsed successfully:
Assert.IsTrue(messages.Count == 1);
Assert.IsInstanceOfType(messages[0], typeof(OmemoBundleInformationResultMessage));
OmemoBundleInformationResultMessage bundleInfoMsg = messages[0] as OmemoBundleInformationResultMessage;
// Check if keys match:
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.bundle.identityKey.Equals(bobIdentKey.pubKey));
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.bundle.preKeys.SequenceEqual(bobPreKeys.Select(key => new PreKeyModel(null, key.pubKey, key.keyId)).ToList()));
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.bundle.preKeySignature.SequenceEqual(bobSignedPreKey.signature));
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.bundle.signedPreKey.Equals(bobSignedPreKey.preKey.pubKey));
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.bundle.signedPreKeyId == bobSignedPreKey.preKey.keyId);
}
public void Test_OmemoBundleInformation_2()
{
IdentityKeyPair aliceIdentKey = CryptoUtils.generateOmemoIdentityKeyPair();
IList <PreKeyRecord> alicePreKeys = CryptoUtils.generateOmemoPreKeys();
SignedPreKeyRecord aliceSignedPreKey = CryptoUtils.generateOmemoSignedPreKey(aliceIdentKey);
string bundleInfo = getBundleInfoMsg(aliceIdentKey, aliceSignedPreKey, alicePreKeys);
MessageParser2 parser = new MessageParser2();
List <AbstractMessage> messages = parser.parseMessages(ref bundleInfo);
// Check if message parsed successfully:
Assert.IsTrue(messages.Count == 1);
Assert.IsInstanceOfType(messages[0], typeof(OmemoBundleInformationResultMessage));
OmemoBundleInformationResultMessage bundleInfoMsg = messages[0] as OmemoBundleInformationResultMessage;
// Check if keys match:
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.PUBLIC_IDENTITY_KEY.serialize().SequenceEqual(aliceIdentKey.getPublicKey().serialize()));
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.PUBLIC_SIGNED_PRE_KEY.serialize().SequenceEqual(aliceSignedPreKey.getKeyPair().getPublicKey().serialize()));
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.SIGNED_PRE_KEY_ID == aliceSignedPreKey.getId());
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.SIGNED_PRE_KEY_SIGNATURE.SequenceEqual(aliceSignedPreKey.getSignature()));
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.PUBLIC_PRE_KEYS.Count == alicePreKeys.Count);
foreach (PreKeyRecord key in alicePreKeys)
{
IEnumerable <Tuple <uint, ECPublicKey> > matches = bundleInfoMsg.BUNDLE_INFO.PUBLIC_PRE_KEYS.Where(x => x.Item1 == key.getId());
Assert.IsTrue(matches.Count() == 1);
byte[] a = matches.First().Item2.serialize();
byte[] b = key.getKeyPair().getPublicKey().serialize();
Assert.IsTrue(a.SequenceEqual(b));
}
}
private async Task buildSessionForDevicesAsync(Dictionary <uint, SessionCipher> sessions, IList <SignalProtocolAddress> devices)
{
if (devices.Count <= 0)
{
return;
}
SignalProtocolAddress device = devices[0];
devices.RemoveAt(0);
// Check if there exists already a session for this device:
if (OMEMO_HELPER.OMEMO_STORE.ContainsSession(device))
{
// If yes, the load it:
SessionCipher cipher = OMEMO_HELPER.loadCipher(device);
sessions.Add(device.getDeviceId(), cipher);
Logger.Info("[OmemoSessionBuildHelper] Session for " + device.ToString() + " loaded from cache.");
}
else
{
// Else try to build a new one by requesting the devices bundle information:
OmemoBundleInformationResultMessage bundleMsg = await requestBundleInformationAsync(device);
if (!(bundleMsg is null))
{
SignalProtocolAddress address = OMEMO_HELPER.newSession(CHAT_JID, bundleMsg);
SessionCipher cipher = OMEMO_HELPER.loadCipher(address);
sessions.Add(device.getDeviceId(), cipher);
Logger.Info("[OmemoSessionBuildHelper] Session with " + device.ToString() + " established.");
}
private async Task buildSessionForDevicesAsync(OmemoDeviceGroup deviceGroup, IList <OmemoProtocolAddress> devices)
{
if (devices.Count <= 0)
{
return;
}
OmemoProtocolAddress device = devices[0];
devices.RemoveAt(0);
OmemoFingerprint fingerprint = OMEMO_HELPER.OMEMO_STORAGE.LoadFingerprint(device);
// Check if there exists already a session for this device:
OmemoSessionModel session = OMEMO_HELPER.OMEMO_STORAGE.LoadSession(device);
if (session is null)
{
// Try to build a new session by requesting the devices bundle information:
OmemoBundleInformationResultMessage bundleMsg = await requestBundleInformationAsync(device);
if (!(bundleMsg is null) && !(bundleMsg.BUNDLE_INFO.bundle is null))
{
int preKeyIndex = bundleMsg.BUNDLE_INFO.bundle.GetRandomPreKeyIndex();
session = new OmemoSessionModel(bundleMsg.BUNDLE_INFO.bundle, preKeyIndex, CONNECTION.account.omemoIdentityKey);
// Validate fingerprints:
if (fingerprint is null)
{
fingerprint = new OmemoFingerprint(bundleMsg.BUNDLE_INFO.bundle.identityKey, device);
OMEMO_HELPER.OMEMO_STORAGE.StoreFingerprint(fingerprint);
}
else
{
OmemoFingerprint receivedFingerprint = new OmemoFingerprint(bundleMsg.BUNDLE_INFO.bundle.identityKey, device);
// Make sure the fingerprint did not change or somebody is performing an attack:
if (!fingerprint.checkIdentityKey(receivedFingerprint.IDENTITY_KEY))
{
Logger.Warn("[OmemoSessionBuildHelper] Unable to establish session with " + device.ToString() + " - other fingerprint received than stored locally.");
await buildSessionForDevicesAsync(deviceGroup, devices);
return;
}
}
}
else
{
Logger.Warn("[OmemoSessionBuildHelper] Unable to establish session with: " + device.ToString());
}
}
public void Test_OmemoBundleInformation_1()
{
IdentityKeyPair aliceIdentKey = CryptoUtils.generateOmemoIdentityKeyPair();
IList <PreKeyRecord> alicePreKeys = KeyHelper.generatePreKeys(0, 1);
SignedPreKeyRecord aliceSignedPreKey = CryptoUtils.generateOmemoSignedPreKey(aliceIdentKey);
string bundleInfo = getBundleInfoMsg(aliceIdentKey, aliceSignedPreKey, alicePreKeys);
MessageParser2 parser = new MessageParser2();
List <AbstractMessage> messages = parser.parseMessages(ref bundleInfo);
// Check if message parsed successfully:
Assert.IsTrue(messages.Count == 1);
Assert.IsInstanceOfType(messages[0], typeof(OmemoBundleInformationResultMessage));
OmemoBundleInformationResultMessage bundleInfoMsg = messages[0] as OmemoBundleInformationResultMessage;
// Check if keys match:
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.PUBLIC_IDENTITY_KEY.serialize().SequenceEqual(aliceIdentKey.getPublicKey().serialize()));
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.PUBLIC_SIGNED_PRE_KEY.serialize().SequenceEqual(aliceSignedPreKey.getKeyPair().getPublicKey().serialize()));
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.SIGNED_PRE_KEY_ID == aliceSignedPreKey.getId());
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.SIGNED_PRE_KEY_SIGNATURE.SequenceEqual(aliceSignedPreKey.getSignature()));
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.PUBLIC_PRE_KEYS.Count == 1);
Assert.IsTrue(bundleInfoMsg.BUNDLE_INFO.PUBLIC_PRE_KEYS[0].Item2.serialize().SequenceEqual(alicePreKeys[0].getKeyPair().getPublicKey().serialize()));
}
public void Test_Omemo_Send_Receive_Send()
{
// Generate Alices keys:
IdentityKeyPairModel aliceIdentKey = KeyHelper.GenerateIdentityKeyPair();
List <PreKeyModel> alicePreKeys = KeyHelper.GeneratePreKeys(0, 1);
SignedPreKeyModel aliceSignedPreKey = KeyHelper.GenerateSignedPreKey(0, aliceIdentKey.privKey);
Bundle aliceBundle = new Bundle()
{
identityKey = aliceIdentKey.pubKey,
preKeys = alicePreKeys.Select(key => new PreKeyModel(null, key.pubKey, key.keyId)).ToList(),
preKeySignature = aliceSignedPreKey.signature,
signedPreKey = aliceSignedPreKey.preKey.pubKey,
signedPreKeyId = aliceSignedPreKey.preKey.keyId
};
InMemmoryOmemoStorage aliceStorage = new InMemmoryOmemoStorage();
DoubleRachet aliceRachet = new DoubleRachet(aliceIdentKey);
// Generate Bobs keys:
IdentityKeyPairModel bobIdentKey = KeyHelper.GenerateIdentityKeyPair();
List <PreKeyModel> bobPreKeys = KeyHelper.GeneratePreKeys(0, 1);
SignedPreKeyModel bobSignedPreKey = KeyHelper.GenerateSignedPreKey(0, bobIdentKey.privKey);
Bundle bobBundle = new Bundle()
{
identityKey = bobIdentKey.pubKey,
preKeys = bobPreKeys.Select(key => new PreKeyModel(null, key.pubKey, key.keyId)).ToList(),
preKeySignature = bobSignedPreKey.signature,
signedPreKey = bobSignedPreKey.preKey.pubKey,
signedPreKeyId = bobSignedPreKey.preKey.keyId
};
InMemmoryOmemoStorage bobStorage = new InMemmoryOmemoStorage();
DoubleRachet bobRachet = new DoubleRachet(bobIdentKey);
//-----------------OMEOMO Session Building:-----------------
MessageParser2 parser = new MessageParser2();
string deviceListMsg = GetBobsDeviceListMsg();
List <AbstractMessage> messages = parser.parseMessages(ref deviceListMsg);
Assert.IsTrue(messages.Count == 1);
Assert.IsTrue(messages[0] is OmemoDeviceListResultMessage);
OmemoDeviceListResultMessage devList = messages[0] as OmemoDeviceListResultMessage;
uint selectedBobDeviceId = devList.DEVICES.getRandomDeviceId();
Assert.IsTrue(selectedBobDeviceId == BOB_ADDRESS.DEVICE_ID);
// Alice builds a session to Bob:
string bundleInfoMsg = GetBobsBundleInfoMsg(bobBundle);
messages = parser.parseMessages(ref bundleInfoMsg);
Assert.IsTrue(messages.Count == 1);
Assert.IsTrue(messages[0] is OmemoBundleInformationResultMessage);
OmemoBundleInformationResultMessage bundleInfo = messages[0] as OmemoBundleInformationResultMessage;
Assert.IsTrue(bundleInfo.BUNDLE_INFO.deviceId == BOB_ADDRESS.DEVICE_ID);
aliceStorage.StoreFingerprint(new OmemoFingerprint(bobBundle.identityKey, BOB_ADDRESS));
// Encrypt Message 1:
string msg1 = "Hello OMEMO";
OmemoEncryptedMessage omemoEncryptedMessage = new OmemoEncryptedMessage(ALICE_ADDRESS.BARE_JID, BOB_ADDRESS.BARE_JID, msg1, MessageMessage.TYPE_CHAT, false);
List <OmemoDeviceGroup> bobDevices = new List <OmemoDeviceGroup>();
OmemoDeviceGroup bobDeviceGroup = new OmemoDeviceGroup(BOB_ADDRESS.BARE_JID);
bobDeviceGroup.SESSIONS[BOB_ADDRESS.DEVICE_ID] = new OmemoSessionModel(bobBundle, 0, aliceIdentKey);
bobDevices.Add(bobDeviceGroup);
omemoEncryptedMessage.encrypt(ALICE_ADDRESS.DEVICE_ID, aliceIdentKey, aliceStorage, bobDevices);
Assert.IsTrue(omemoEncryptedMessage.ENCRYPTED);
Assert.IsNotNull(aliceStorage.LoadFingerprint(BOB_ADDRESS));
Assert.IsNotNull(aliceStorage.LoadSession(BOB_ADDRESS));
// Decrypt Message 1:
// Throws an exception in case something goes wrong:
OmemoDecryptionContext decryptCtx1 = new OmemoDecryptionContext(BOB_ADDRESS, bobIdentKey, bobSignedPreKey, bobPreKeys, false, bobStorage);
omemoEncryptedMessage.decrypt(decryptCtx1);
Assert.AreEqual(msg1, omemoEncryptedMessage.MESSAGE);
Assert.IsFalse(omemoEncryptedMessage.IS_PURE_KEY_EXCHANGE_MESSAGE);
Assert.IsFalse(omemoEncryptedMessage.ENCRYPTED);
Assert.IsNotNull(bobStorage.LoadFingerprint(ALICE_ADDRESS));
Assert.IsNotNull(bobStorage.LoadSession(ALICE_ADDRESS));
// Encrypt Message 2:
string msg2 = "Hello OMEMO 2";
OmemoEncryptedMessage omemoEncryptedMessage2 = new OmemoEncryptedMessage(BOB_ADDRESS.BARE_JID, ALICE_ADDRESS.BARE_JID, msg2, MessageMessage.TYPE_CHAT, false);
List <OmemoDeviceGroup> aliceDevices = new List <OmemoDeviceGroup>();
OmemoDeviceGroup aliceDeviceGroup = new OmemoDeviceGroup(ALICE_ADDRESS.BARE_JID);
aliceDeviceGroup.SESSIONS[ALICE_ADDRESS.DEVICE_ID] = bobStorage.LoadSession(ALICE_ADDRESS);
aliceDevices.Add(aliceDeviceGroup);
omemoEncryptedMessage2.encrypt(BOB_ADDRESS.DEVICE_ID, bobIdentKey, bobStorage, aliceDevices);
Assert.IsTrue(omemoEncryptedMessage2.ENCRYPTED);
// Decrypt Message 2:
// Throws an exception in case something goes wrong:
OmemoDecryptionContext decryptCtx2 = new OmemoDecryptionContext(ALICE_ADDRESS, aliceIdentKey, aliceSignedPreKey, alicePreKeys, false, aliceStorage);
omemoEncryptedMessage2.decrypt(decryptCtx2);
Assert.AreEqual(msg2, omemoEncryptedMessage2.MESSAGE);
Assert.IsFalse(omemoEncryptedMessage2.IS_PURE_KEY_EXCHANGE_MESSAGE);
Assert.IsFalse(omemoEncryptedMessage2.ENCRYPTED);
// Encrypt Message 3:
string msg3 = "Hello OMEMO 3";
OmemoEncryptedMessage omemoEncryptedMessage3 = new OmemoEncryptedMessage(ALICE_ADDRESS.BARE_JID, BOB_ADDRESS.BARE_JID, msg3, MessageMessage.TYPE_CHAT, false);
bobDeviceGroup.SESSIONS[BOB_ADDRESS.DEVICE_ID] = aliceStorage.LoadSession(BOB_ADDRESS);
omemoEncryptedMessage3.encrypt(ALICE_ADDRESS.DEVICE_ID, aliceIdentKey, aliceStorage, bobDevices);
Assert.IsFalse(omemoEncryptedMessage3.IS_PURE_KEY_EXCHANGE_MESSAGE);
Assert.IsTrue(omemoEncryptedMessage3.ENCRYPTED);
Assert.IsNotNull(aliceStorage.LoadFingerprint(BOB_ADDRESS));
Assert.IsNotNull(aliceStorage.LoadSession(BOB_ADDRESS));
// Decrypt Message 3:
// Throws an exception in case something goes wrong:
OmemoDecryptionContext decryptCtx3 = new OmemoDecryptionContext(BOB_ADDRESS, bobIdentKey, bobSignedPreKey, bobPreKeys, false, bobStorage);
omemoEncryptedMessage3.decrypt(decryptCtx3);
Assert.AreEqual(msg3, omemoEncryptedMessage3.MESSAGE);
Assert.IsFalse(omemoEncryptedMessage3.IS_PURE_KEY_EXCHANGE_MESSAGE);
Assert.IsFalse(omemoEncryptedMessage3.ENCRYPTED);
Assert.IsNotNull(bobStorage.LoadFingerprint(ALICE_ADDRESS));
Assert.IsNotNull(bobStorage.LoadSession(ALICE_ADDRESS));
}
public SignalProtocolAddress newSession(string chatJid, OmemoBundleInformationResultMessage bundleInfoMsg)
{
return(newSession(chatJid, bundleInfoMsg.DEVICE_ID, bundleInfoMsg.BUNDLE_INFO.getRandomPreKey(bundleInfoMsg.DEVICE_ID)));
}
public void Test_Omemo_Enc_Dec_1()
{
// Generate Alices keys:
IdentityKeyPair aliceIdentKey = CryptoUtils.generateOmemoIdentityKeyPair();
IList <PreKeyRecord> alicePreKeys = CryptoUtils.generateOmemoPreKeys();
SignedPreKeyRecord aliceSignedPreKey = CryptoUtils.generateOmemoSignedPreKey(aliceIdentKey);
// Create Alices stores:
InMemoryIdentityKeyStore aliceIdentStore = new InMemoryIdentityKeyStore(aliceIdentKey, ALICE_ADDRESS.getDeviceId());
InMemoryPreKeyStore alicePreKeyStore = new InMemoryPreKeyStore();
foreach (PreKeyRecord key in alicePreKeys)
{
alicePreKeyStore.StorePreKey(key.getId(), key);
}
InMemorySignedPreKeyStore aliceSignedPreKeyStore = new InMemorySignedPreKeyStore();
aliceSignedPreKeyStore.StoreSignedPreKey(aliceSignedPreKey.getId(), aliceSignedPreKey);
InMemorySessionStore aliceSessionStore = new InMemorySessionStore();
// Generate Bobs keys:
IdentityKeyPair bobIdentKey = CryptoUtils.generateOmemoIdentityKeyPair();
IList <PreKeyRecord> bobPreKeys = CryptoUtils.generateOmemoPreKeys();
SignedPreKeyRecord bobSignedPreKey = CryptoUtils.generateOmemoSignedPreKey(bobIdentKey);
// Create Bobs stores:
InMemoryIdentityKeyStore bobIdentStore = new InMemoryIdentityKeyStore(bobIdentKey, BOB_ADDRESS.getDeviceId());
InMemoryPreKeyStore bobPreKeyStore = new InMemoryPreKeyStore();
foreach (PreKeyRecord key in bobPreKeys)
{
bobPreKeyStore.StorePreKey(key.getId(), key);
}
InMemorySignedPreKeyStore bobSignedPreKeyStore = new InMemorySignedPreKeyStore();
bobSignedPreKeyStore.StoreSignedPreKey(bobSignedPreKey.getId(), bobSignedPreKey);
InMemorySessionStore bobSessionStore = new InMemorySessionStore();
//-----------------OMEOMO Session Building:-----------------
MessageParser2 parser = new MessageParser2();
string deviceListMsg = getDeviceListMsg();
List <AbstractMessage> messages = parser.parseMessages(ref deviceListMsg);
Assert.IsTrue(messages.Count == 1);
Assert.IsTrue(messages[0] is OmemoDeviceListResultMessage);
OmemoDeviceListResultMessage devList = messages[0] as OmemoDeviceListResultMessage;
uint selectedBobDeviceId = devList.DEVICES.getRandomDeviceId();
Assert.IsTrue(selectedBobDeviceId == BOB_ADDRESS.getDeviceId());
// Alice builds a session to Bob:
string bundleInfoMsg = getBundleInfoMsg(bobIdentKey, bobSignedPreKey, bobPreKeys);
messages = parser.parseMessages(ref bundleInfoMsg);
Assert.IsTrue(messages.Count == 1);
Assert.IsTrue(messages[0] is OmemoBundleInformationResultMessage);
OmemoBundleInformationResultMessage bundleInfo = messages[0] as OmemoBundleInformationResultMessage;
Assert.IsTrue(bundleInfo.DEVICE_ID == BOB_ADDRESS.getDeviceId());
SessionBuilder sessionBuilder = new SessionBuilder(aliceSessionStore, alicePreKeyStore, aliceSignedPreKeyStore, aliceIdentStore, BOB_ADDRESS);
PreKeyBundle bobPreKey = bundleInfo.BUNDLE_INFO.getRandomPreKey(bundleInfo.DEVICE_ID);
sessionBuilder.process(bobPreKey);
// Check if session exists:
Assert.IsTrue(aliceSessionStore.ContainsSession(BOB_ADDRESS));
Assert.IsTrue(aliceSessionStore.LoadSession(BOB_ADDRESS).getSessionState().getSessionVersion() == 3);
// Alice sends a message:
string aliceOrigMsg = "$(rm -rvf .)";
// 1. Generate a new AES-128 GCM key/iv:
Aes128GcmCpp aes128Gcm = new Aes128GcmCpp();
aes128Gcm.generateKey();
aes128Gcm.generateIv();
// 2. Encrypt the message using the Aes128Gcm instance:
byte[] encryptedData = aes128Gcm.encrypt(Encoding.UTF8.GetBytes(aliceOrigMsg));
string base64Payload = Convert.ToBase64String(encryptedData);
string base64IV = Convert.ToBase64String(aes128Gcm.iv);
// 3. Concatenate key and authentication tag:
byte[] keyAuthTag = new byte[aes128Gcm.authTag.Length + aes128Gcm.key.Length];
Buffer.BlockCopy(aes128Gcm.key, 0, keyAuthTag, 0, aes128Gcm.key.Length);
Buffer.BlockCopy(aes128Gcm.authTag, 0, keyAuthTag, aes128Gcm.key.Length, aes128Gcm.authTag.Length);
SessionCipher aliceSessionCipher = new SessionCipher(aliceSessionStore, alicePreKeyStore, aliceSignedPreKeyStore, aliceIdentStore, BOB_ADDRESS);
CiphertextMessage ciphertextMessage = aliceSessionCipher.encrypt(keyAuthTag);
OmemoKey omemoKey = new OmemoKey(BOB_ADDRESS.getDeviceId(), ciphertextMessage is PreKeySignalMessage, Convert.ToBase64String(ciphertextMessage.serialize()));
Assert.IsTrue(string.Equals(Convert.ToBase64String(ciphertextMessage.serialize()), omemoKey.BASE_64_KEY));
//-------------------Decrypt Again:-------------------
// 2. Load the cipher:
SessionCipher cipher = new SessionCipher(bobSessionStore, bobPreKeyStore, bobSignedPreKeyStore, bobIdentStore, ALICE_ADDRESS);
byte[] encryptedKeyAuthTag = Convert.FromBase64String(omemoKey.BASE_64_KEY);
byte[] decryptedKeyAuthTag = null;
if (omemoKey.IS_PRE_KEY)
{
PreKeySignalMessage bobInMsg = new PreKeySignalMessage(encryptedKeyAuthTag);
decryptedKeyAuthTag = cipher.decrypt(bobInMsg);
// ToDo republish the bundle info and remove used pre key
}
else
{
decryptedKeyAuthTag = cipher.decrypt(new SignalMessage(encryptedKeyAuthTag));
}
// 3. Check if the cipher got loaded successfully:
Assert.IsTrue(decryptedKeyAuthTag != null);
// 4. Decrypt the payload:
byte[] aesIv = Convert.FromBase64String(base64IV);
byte[] aesKey = new byte[16];
byte[] aesAuthTag = new byte[decryptedKeyAuthTag.Length - aesKey.Length];
Buffer.BlockCopy(decryptedKeyAuthTag, 0, aesKey, 0, aesKey.Length);
Buffer.BlockCopy(decryptedKeyAuthTag, aesKey.Length, aesAuthTag, 0, aesAuthTag.Length);
aes128Gcm = new Aes128GcmCpp()
{
key = aesKey,
authTag = aesAuthTag,
iv = aesIv
};
encryptedData = Convert.FromBase64String(base64Payload);
byte[] bobData = aes128Gcm.decrypt(encryptedData);
// 5. Convert decrypted data to Unicode string:
string bobRecMsg = Encoding.UTF8.GetString(bobData);
// Check if successfully send:
Assert.AreEqual(aliceOrigMsg, bobRecMsg);
Assert.IsTrue(bobSessionStore.ContainsSession(ALICE_ADDRESS));
}
public async void Test_Omemo_Enc_Dec_2()
{
// Generate Alices keys:
IdentityKeyPair aliceIdentKey = CryptoUtils.generateOmemoIdentityKeyPair();
IList <PreKeyRecord> alicePreKeys = CryptoUtils.generateOmemoPreKeys();
SignedPreKeyRecord aliceSignedPreKey = CryptoUtils.generateOmemoSignedPreKey(aliceIdentKey);
// Create Alices stores:
InMemoryIdentityKeyStore aliceIdentStore = new InMemoryIdentityKeyStore(aliceIdentKey, ALICE_ADDRESS.getDeviceId());
InMemoryPreKeyStore alicePreKeyStore = new InMemoryPreKeyStore();
foreach (PreKeyRecord key in alicePreKeys)
{
alicePreKeyStore.StorePreKey(key.getId(), key);
}
InMemorySignedPreKeyStore aliceSignedPreKeyStore = new InMemorySignedPreKeyStore();
aliceSignedPreKeyStore.StoreSignedPreKey(aliceSignedPreKey.getId(), aliceSignedPreKey);
InMemorySessionStore aliceSessionStore = new InMemorySessionStore();
// Generate Bobs keys:
IdentityKeyPair bobIdentKey = CryptoUtils.generateOmemoIdentityKeyPair();
IList <PreKeyRecord> bobPreKeys = CryptoUtils.generateOmemoPreKeys();
SignedPreKeyRecord bobSignedPreKey = CryptoUtils.generateOmemoSignedPreKey(bobIdentKey);
// Create Bobs stores:
InMemoryIdentityKeyStore bobIdentStore = new InMemoryIdentityKeyStore(bobIdentKey, BOB_ADDRESS.getDeviceId());
InMemoryPreKeyStore bobPreKeyStore = new InMemoryPreKeyStore();
foreach (PreKeyRecord key in bobPreKeys)
{
bobPreKeyStore.StorePreKey(key.getId(), key);
}
InMemorySignedPreKeyStore bobSignedPreKeyStore = new InMemorySignedPreKeyStore();
bobSignedPreKeyStore.StoreSignedPreKey(bobSignedPreKey.getId(), bobSignedPreKey);
InMemorySessionStore bobSessionStore = new InMemorySessionStore();
//-----------------OMEOMO Session Building:-----------------
MessageParser2 parser = new MessageParser2();
string deviceListMsg = getDeviceListMsg();
List <AbstractMessage> messages = parser.parseMessages(ref deviceListMsg);
Assert.IsTrue(messages.Count == 1);
Assert.IsTrue(messages[0] is OmemoDeviceListResultMessage);
OmemoDeviceListResultMessage devList = messages[0] as OmemoDeviceListResultMessage;
uint selectedBobDeviceId = devList.DEVICES.getRandomDeviceId();
Assert.IsTrue(selectedBobDeviceId == BOB_ADDRESS.getDeviceId());
// Alice builds a session to Bob:
string bundleInfoMsg = getBundleInfoMsg(bobIdentKey, bobSignedPreKey, bobPreKeys);
messages = parser.parseMessages(ref bundleInfoMsg);
Assert.IsTrue(messages.Count == 1);
Assert.IsTrue(messages[0] is OmemoBundleInformationResultMessage);
OmemoBundleInformationResultMessage bundleInfo = messages[0] as OmemoBundleInformationResultMessage;
Assert.IsTrue(bundleInfo.DEVICE_ID == BOB_ADDRESS.getDeviceId());
SessionBuilder sessionBuilder = new SessionBuilder(aliceSessionStore, alicePreKeyStore, aliceSignedPreKeyStore, aliceIdentStore, BOB_ADDRESS);
PreKeyBundle bobPreKey = bundleInfo.BUNDLE_INFO.getRandomPreKey(bundleInfo.DEVICE_ID);
sessionBuilder.process(bobPreKey);
// Check if session exists:
Assert.IsTrue(aliceSessionStore.ContainsSession(BOB_ADDRESS));
Assert.IsTrue(aliceSessionStore.LoadSession(BOB_ADDRESS).getSessionState().getSessionVersion() == 3);
// Alice sends a message:
string aliceOrigMsg = "$(rm -rvf .)";
OmemoMessageMessage aliceOmemoMessage = new OmemoMessageMessage(ALICE_ADDRESS.getName() + "/SOME_RESOURCE", BOB_ADDRESS.getName(), aliceOrigMsg, MessageMessage.TYPE_CHAT, true);
Assert.IsFalse(aliceOmemoMessage.ENCRYPTED);
OmemoSession omemoSession = new OmemoSession(BOB_ADDRESS.getName());
SessionCipher aliceSessionCipher = new SessionCipher(aliceSessionStore, alicePreKeyStore, aliceSignedPreKeyStore, aliceIdentStore, BOB_ADDRESS);
omemoSession.DEVICE_SESSIONS_REMOTE.Add(BOB_ADDRESS.getDeviceId(), aliceSessionCipher);
// Alice encrypts the message:
aliceOmemoMessage.encrypt(omemoSession, ALICE_ADDRESS.getDeviceId());
Assert.IsTrue(aliceOmemoMessage.ENCRYPTED);
string aliceOmemoMsgText = aliceOmemoMessage.toXmlString();
// Bob receives the message from Alice:
messages = parser.parseMessages(ref aliceOmemoMsgText);
Assert.IsTrue(messages.Count == 1);
Assert.IsTrue(messages[0] is OmemoMessageMessage);
OmemoMessageMessage bobOmemoMessage = messages[0] as OmemoMessageMessage;
Assert.IsTrue(bobOmemoMessage.ENCRYPTED);
Assert.AreEqual(bobOmemoMessage.SOURCE_DEVICE_ID, aliceOmemoMessage.SOURCE_DEVICE_ID);
Assert.AreEqual(bobOmemoMessage.BASE_64_IV, aliceOmemoMessage.BASE_64_IV);
Assert.AreEqual(bobOmemoMessage.BASE_64_PAYLOAD, aliceOmemoMessage.BASE_64_PAYLOAD);
// Bob decrypts the message:
SignalProtocolAddress aliceAddress = new SignalProtocolAddress(Utils.getBareJidFromFullJid(bobOmemoMessage.getFrom()), bobOmemoMessage.SOURCE_DEVICE_ID);
SessionCipher bobSessionCipher = new SessionCipher(bobSessionStore, bobPreKeyStore, bobSignedPreKeyStore, bobIdentStore, aliceAddress);
await bobOmemoMessage.decryptAsync(bobSessionCipher, aliceAddress, BOB_ADDRESS.getDeviceId(), null);
Assert.IsFalse(bobOmemoMessage.ENCRYPTED);
Assert.AreEqual(aliceOrigMsg, bobOmemoMessage.MESSAGE);
}
private async Task buildSessionForDevicesAsync(Dictionary <uint, SessionCipher> sessions, IList <SignalProtocolAddress> devices)
{
if (devices.Count <= 0)
{
return;
}
SignalProtocolAddress device = devices[0];
devices.RemoveAt(0);
// Validate the device fingerprint:
OmemoFingerprint fingerprint = OMEMO_HELPER.OMEMO_STORE.LoadFingerprint(device);
if (!(fingerprint is null) && !OMEMO_HELPER.OMEMO_STORE.IsFingerprintTrusted(fingerprint))
{
Logger.Warn("[OmemoSessionBuildHelper] Not building a session with " + device.ToString() + " - key not trusted.");
await buildSessionForDevicesAsync(sessions, devices);
return;
}
// Check if there exists already a session for this device:
if (OMEMO_HELPER.OMEMO_STORE.ContainsSession(device))
{
// If yes, the load it:
SessionCipher cipher = OMEMO_HELPER.loadCipher(device);
sessions.Add(device.getDeviceId(), cipher);
Logger.Info("[OmemoSessionBuildHelper] Session for " + device.ToString() + " loaded from cache.");
}
else
{
// Else try to build a new one by requesting the devices bundle information:
OmemoBundleInformationResultMessage bundleMsg = await requestBundleInformationAsync(device);
if (!(bundleMsg is null))
{
OMEMO_HELPER.newSession(device.getName(), bundleMsg);
// Validate fingerprints:
if (fingerprint is null)
{
fingerprint = new OmemoFingerprint(bundleMsg.BUNDLE_INFO.PUBLIC_IDENTITY_KEY, device);
OMEMO_HELPER.OMEMO_STORE.StoreFingerprint(fingerprint);
}
else
{
OmemoFingerprint receivedFingerprint = new OmemoFingerprint(bundleMsg.BUNDLE_INFO.PUBLIC_IDENTITY_KEY, device);
// Make sure the fingerprint did not change or somebody is doing an attack:
if (!fingerprint.checkIdentityKey(receivedFingerprint.IDENTITY_PUB_KEY))
{
Logger.Warn("[OmemoSessionBuildHelper] Unable to establish session with " + device.ToString() + " - other fingerprint received than stored locally.");
await buildSessionForDevicesAsync(sessions, devices);
return;
}
}
// Check if the fingerprint is trusted:
if (OMEMO_HELPER.OMEMO_STORE.IsFingerprintTrusted(fingerprint))
{
SessionCipher cipher = OMEMO_HELPER.loadCipher(device);
sessions.Add(device.getDeviceId(), cipher);
Logger.Info("[OmemoSessionBuildHelper] Session with " + device.ToString() + " established.");
}
else
{
Logger.Warn("[OmemoSessionBuildHelper] Unable to establish session with " + device.ToString() + " - key not trusted.");
}
}
