public void handle(SignalServiceEnvelope envelope, bool sendExplicitReceipt) { if (!isActiveNumber(envelope.getSource())) { TextSecureDirectory directory = DatabaseFactory.getDirectoryDatabase(); ContactTokenDetails contactTokenDetails = new ContactTokenDetails(); contactTokenDetails.setNumber(envelope.getSource()); directory.setNumber(contactTokenDetails, true); // TODO: evtl DirectoryRefresh } if (envelope.isReceipt()) { handleReceipt(envelope); } else if (envelope.isPreKeySignalMessage() || envelope.isSignalMessage()) { handleMessage(envelope, sendExplicitReceipt); } else { Log.Warn($"Received envelope of unknown type: {envelope.GetType()}"); } }
/// <summary> /// /// </summary> /// <param name="envelope"></param> /// <param name="ciphertext"></param> /// <returns></returns> /// <exception cref="InvalidMetadataMessageException"></exception> /// <exception cref="InvalidMetadataVersionException"></exception> /// <exception cref="ProtocolDuplicateMessageException"></exception> /// <exception cref="ProtocolUntrustedIdentityException"></exception> /// <exception cref="ProtocolLegacyMessageException"></exception> /// <exception cref="ProtocolInvalidKeyException"></exception> /// <exception cref="ProtocolInvalidVersionException"></exception> /// <exception cref="ProtocolInvalidMessageException"></exception> /// <exception cref="ProtocolInvalidKeyIdException"></exception> /// <exception cref="ProtocolNoSessionException"></exception> /// <exception cref="SelfSendException"></exception> private Plaintext Decrypt(SignalServiceEnvelope envelope, byte[] ciphertext) { try { byte[] paddedMessage; SignalServiceMetadata metadata; uint sessionVersion; if (!envelope.HasSource() && !envelope.IsUnidentifiedSender()) { throw new ProtocolInvalidMessageException(new InvalidMessageException("Non-UD envelope is missing a source!"), null, 0); } if (envelope.IsPreKeySignalMessage()) { SignalProtocolAddress sourceAddress = GetPreferredProtocolAddress(signalProtocolStore, envelope.GetSourceAddress(), envelope.GetSourceDevice()); SessionCipher sessionCipher = new SessionCipher(signalProtocolStore, sourceAddress); paddedMessage = sessionCipher.decrypt(new PreKeySignalMessage(ciphertext)); metadata = new SignalServiceMetadata(envelope.GetSourceAddress(), envelope.GetSourceDevice(), envelope.GetTimestamp(), false); sessionVersion = sessionCipher.getSessionVersion(); } else if (envelope.IsSignalMessage()) { SignalProtocolAddress sourceAddress = GetPreferredProtocolAddress(signalProtocolStore, envelope.GetSourceAddress(), envelope.GetSourceDevice()); SessionCipher sessionCipher = new SessionCipher(signalProtocolStore, sourceAddress); paddedMessage = sessionCipher.decrypt(new SignalMessage(ciphertext)); metadata = new SignalServiceMetadata(envelope.GetSourceAddress(), envelope.GetSourceDevice(), envelope.GetTimestamp(), false); sessionVersion = sessionCipher.getSessionVersion(); } else if (envelope.IsUnidentifiedSender()) { SealedSessionCipher sealedSessionCipher = new SealedSessionCipher(signalProtocolStore, localAddress.Uuid, localAddress.GetNumber(), 1); DecryptionResult result = sealedSessionCipher.Decrypt(certificateValidator !, ciphertext, (long)envelope.Envelope.ServerTimestamp); SignalServiceAddress resultAddress = new SignalServiceAddress(UuidUtil.Parse(result.SenderUuid), result.SenderE164); SignalProtocolAddress protocolAddress = GetPreferredProtocolAddress(signalProtocolStore, resultAddress, result.DeviceId); paddedMessage = result.PaddedMessage; metadata = new SignalServiceMetadata(resultAddress, result.DeviceId, envelope.GetTimestamp(), true); sessionVersion = (uint)sealedSessionCipher.GetSessionVersion(protocolAddress); } else { throw new InvalidMessageException($"Unknown type: {envelope.GetType()}"); } PushTransportDetails transportDetails = new PushTransportDetails(sessionVersion); byte[] data = transportDetails.GetStrippedPaddingMessageBody(paddedMessage); return(new Plaintext(metadata, data)); } catch (DuplicateMessageException e) { throw new ProtocolDuplicateMessageException(e, envelope.GetSourceIdentifier(), envelope.GetSourceDevice()); } catch (LegacyMessageException e) { throw new ProtocolLegacyMessageException(e, envelope.GetSourceIdentifier(), envelope.GetSourceDevice()); } catch (InvalidMessageException e) { throw new ProtocolInvalidMessageException(e, envelope.GetSourceIdentifier(), envelope.GetSourceDevice()); } catch (InvalidKeyIdException e) { throw new ProtocolInvalidKeyIdException(e, envelope.GetSourceIdentifier(), envelope.GetSourceDevice()); } catch (InvalidKeyException e) { throw new ProtocolInvalidKeyException(e, envelope.GetSourceIdentifier(), envelope.GetSourceDevice()); } catch (libsignal.exceptions.UntrustedIdentityException e) { throw new ProtocolUntrustedIdentityException(e, envelope.GetSourceIdentifier(), envelope.GetSourceDevice()); } catch (InvalidVersionException e) { throw new ProtocolInvalidVersionException(e, envelope.GetSourceIdentifier(), envelope.GetSourceDevice()); } catch (NoSessionException e) { throw new ProtocolNoSessionException(e, envelope.GetSourceIdentifier(), envelope.GetSourceDevice()); } }