SignalMessage.fromSerialized constructor

SignalMessage.fromSerialized(Uint8List serialized)

Implementation

SignalMessage.fromSerialized(Uint8List serialized) {
  try {
    final messageParts = ByteUtil.split(
        serialized, 1, serialized.length - 1 - macLength, macLength);
    final version = messageParts[0].first;
    final message = messageParts[1];
    // ignore: unused_local_variable
    final mac = messageParts[2];

    if (ByteUtil.highBitsToInt(version) < CiphertextMessage.currentVersion) {
      throw LegacyMessageException(
          'Legacy message: $ByteUtil.highBitsToInt(version)');
    }

    if (ByteUtil.highBitsToInt(version) > CiphertextMessage.currentVersion) {
      throw InvalidMessageException(
          'Unknown version: $ByteUtil.highBitsToInt(version)');
    }

    final whisperMessage = signal_protos.SignalMessage.fromBuffer(message);

    if (!whisperMessage.hasCiphertext() ||
        !whisperMessage.hasCounter() ||
        !whisperMessage.hasRatchetKey()) {
      throw InvalidMessageException('Incomplete message.');
    }

    _serialized = serialized;
    _senderRatchetKey =
        Curve.decodePoint(Uint8List.fromList(whisperMessage.ratchetKey), 0);
    _messageVersion = ByteUtil.highBitsToInt(version);
    _counter = whisperMessage.counter;
    _previousCounter = whisperMessage.previousCounter;
    _ciphertext = Uint8List.fromList(whisperMessage.ciphertext);
  } on InvalidProtocolBufferException catch (e) {
    throw InvalidMessageException(e.toString());
  } on InvalidKeyException catch (e) {
    throw InvalidMessageException(e.detailMessage);
  }
}