private static async Task <MqttBasePacket> DeserializeConnectAsync(MqttPacketReader reader) { await reader.ReadRemainingDataAsync(2); // Skip 2 bytes var protocolName = await reader.ReadRemainingDataAsync(4); if (Encoding.UTF8.GetString(protocolName, 0, protocolName.Length) != "MQTT") { throw new MqttProtocolViolationException("Protocol name is not 'MQTT'."); } var protocolLevel = await reader.ReadRemainingDataByteAsync(); var connectFlags = await reader.ReadRemainingDataByteAsync(); var connectFlagsReader = new ByteReader(connectFlags); connectFlagsReader.Read(); // Reserved. var packet = new MqttConnectPacket { CleanSession = connectFlagsReader.Read() }; var willFlag = connectFlagsReader.Read(); var willQoS = connectFlagsReader.Read(2); var willRetain = connectFlagsReader.Read(); var passwordFlag = connectFlagsReader.Read(); var usernameFlag = connectFlagsReader.Read(); packet.KeepAlivePeriod = await reader.ReadRemainingDataUShortAsync(); packet.ClientId = await reader.ReadRemainingDataStringWithLengthPrefixAsync(); if (willFlag) { packet.WillMessage = new MqttApplicationMessage( await reader.ReadRemainingDataStringWithLengthPrefixAsync(), await reader.ReadRemainingDataWithLengthPrefixAsync(), (MqttQualityOfServiceLevel)willQoS, willRetain); } if (usernameFlag) { packet.Username = await reader.ReadRemainingDataStringWithLengthPrefixAsync(); } if (passwordFlag) { packet.Password = await reader.ReadRemainingDataStringWithLengthPrefixAsync(); } ValidateConnectPacket(packet); return(packet); }