public async Task decryptOmemoEncryptedMessageAsync(OmemoEncryptedMessage msg, bool trustedKeysOnly) { XMPPAccount account = CONNECTION.account; OmemoProtocolAddress receiverAddress = new OmemoProtocolAddress(account.getBareJid(), account.omemoDeviceId); // Try to decrypt the message, in case no exception occurred, everything went fine: OmemoDecryptionContext decryptCtx = new OmemoDecryptionContext(receiverAddress, account.omemoIdentityKey, account.omemoSignedPreKey, account.OMEMO_PRE_KEYS, trustedKeysOnly, OMEMO_STORAGE); msg.decrypt(decryptCtx); Debug.Assert(!msg.ENCRYPTED); Logger.Debug("Successfully decrypted an " + nameof(OmemoEncryptedMessage) + " for '" + receiverAddress.BARE_JID + "'."); // Republish bundle information in case the message is a key exchange message and used a PreKey: if (decryptCtx.keyExchange) { Logger.Info("Received a OMEMO key exchange message. Republishing bundle for '" + receiverAddress.BARE_JID + "'..."); PreKeyModel newPreKey = decryptCtx.STORAGE.ReplaceOmemoPreKey(decryptCtx.usedPreKey); account.OMEMO_PRE_KEYS.Remove(decryptCtx.usedPreKey); account.OMEMO_PRE_KEYS.Add(newPreKey); await announceBundleInfoAsync(); Logger.Info("Bundle for '" + receiverAddress.BARE_JID + "' republished."); // Reply with an empty message to confirm the successful key exchange: // TODO: This is no good way, since there it would be possible to stalk people without them knowing. OmemoEncryptedMessage reply = new OmemoEncryptedMessage(msg.getTo(), msg.getFrom(), null, msg.TYPE, false); OmemoDeviceGroup deviceGroup = new OmemoDeviceGroup(decryptCtx.senderAddress.BARE_JID); deviceGroup.SESSIONS.Add(decryptCtx.senderAddress.DEVICE_ID, decryptCtx.session); try { reply.encrypt(CONNECTION.account.omemoDeviceId, CONNECTION.account.omemoIdentityKey, OMEMO_STORAGE, new List <OmemoDeviceGroup> { deviceGroup }); await CONNECTION.SendAsync(reply); } catch (Exception e) { Logger.Error("[OMEMO HELPER] Failed to encrypt and the empty OMEMO message reply with: ", e); } Logger.Info($"Send an empty OMEMO message to confirm the successful key exchange with '{msg.getFrom()}'."); } }
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)); }