/// <summary>
/// Encrypts the message and prepares everything for sending it.
/// </summary>
/// <param name="sid">The device ID of the sender.</param>
/// <param name="senderIdentityKey">The identity key pair of the sender.</param>
/// <param name="storage">An instance of the <see cref="IOmemoStorage"/> interface.</param>
/// <param name="devices">A collection of <see cref="OmemoDeviceGroup"/>s the message should be encrypted for.</param>
public void encrypt(uint sid, IdentityKeyPairModel senderIdentityKey, IOmemoStorage storage, List <OmemoDeviceGroup> devices)
{
try
{
SID = sid;
if (IS_PURE_KEY_EXCHANGE_MESSAGE)
{
// Encrypt 32 zero bytes as dummy data for devices:
DoubleRachet rachet = new DoubleRachet(senderIdentityKey);
keys = rachet.EncryptKeyHmacForDevices(new byte[32], devices).Select(x => new OmemoKeys(x.Item1, x.Item2.Select(x => new OmemoKey(x)).ToList())).ToList();
}
else
{
XElement contentNode = generateEnvelope();
byte[] contentData = Encoding.UTF8.GetBytes(contentNode.ToString());
// Encrypt message:
DoubleRachet rachet = new DoubleRachet(senderIdentityKey);
Tuple <byte[], byte[]> encrypted = rachet.EncryptMessasge(contentData);
BASE_64_PAYLOAD = Convert.ToBase64String(encrypted.Item1);
// Encrypt key || HMAC for devices:
keys = rachet.EncryptKeyHmacForDevices(encrypted.Item2, devices).Select(x => new OmemoKeys(x.Item1, x.Item2.Select(x => new OmemoKey(x)).ToList())).ToList();
}
// Store all sessions:
foreach (OmemoDeviceGroup group in devices)
{
foreach (KeyValuePair <uint, OmemoSessionModel> device in group.SESSIONS)
{
// Only store sessions in case encryption for this device was successful:
if (!(keys.Where(k => string.Equals(k.BARE_JID, group.BARE_JID)).FirstOrDefault()?.KEYS.Where(k => k.DEVICE_ID == device.Key).FirstOrDefault() is null))
{
storage.StoreSession(new OmemoProtocolAddress(group.BARE_JID, device.Key), device.Value);
}
}
}
ENCRYPTED = true;
}
catch (Exception e)
{
if (e is OmemoException)
{
throw e;
}
throw new OmemoException("Failed to encrypt.", e);
}
}
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));
}
