static void DecodeConnectPacket(Packet buffer, ConnectPacket packet, ref Int32 remainingLength, IHandlerContext context)
{
var protocolName = DecodeString(buffer, ref remainingLength);
if (!Util.ProtocolName.Equals(protocolName, StringComparison.Ordinal))
{
throw new DecoderException($"Unexpected protocol name. Expected: {Util.ProtocolName}. Actual: {protocolName}");
}
packet.ProtocolName = Util.ProtocolName;
DecreaseRemainingLength(ref remainingLength, 1);
packet.ProtocolLevel = buffer.ReadByte();
if (packet.ProtocolLevel != Util.ProtocolLevel)
{
var connAckPacket = new ConnAckPacket();
connAckPacket.ReturnCode = ConnectReturnCode.RefusedUnacceptableProtocolVersion;
context.WriteAndFlushAsync(connAckPacket);
throw new DecoderException($"Unexpected protocol level. Expected: {Util.ProtocolLevel}. Actual: {packet.ProtocolLevel}");
}
DecreaseRemainingLength(ref remainingLength, 1);
Int32 connectFlags = buffer.ReadByte();
packet.CleanSession = (connectFlags & 0x02) == 0x02;
var hasWill = (connectFlags & 0x04) == 0x04;
if (hasWill)
{
packet.HasWill = true;
packet.WillRetain = (connectFlags & 0x20) == 0x20;
packet.WillQualityOfService = (QualityOfService)((connectFlags & 0x18) >> 3);
if (packet.WillQualityOfService == QualityOfService.Reserved)
{
throw new DecoderException($"[MQTT-3.1.2-14] Unexpected Will QoS value of {(Int32)packet.WillQualityOfService}.");
}
packet.WillTopicName = String.Empty;
}
else if ((connectFlags & 0x38) != 0) // bits 3,4,5 [MQTT-3.1.2-11]
{
throw new DecoderException("[MQTT-3.1.2-11]");
}
packet.HasUsername = (connectFlags & 0x80) == 0x80;
packet.HasPassword = (connectFlags & 0x40) == 0x40;
if (packet.HasPassword && !packet.HasUsername)
{
throw new DecoderException("[MQTT-3.1.2-22]");
}
if ((connectFlags & 0x1) != 0) // [MQTT-3.1.2-3]
{
throw new DecoderException("[MQTT-3.1.2-3]");
}
packet.KeepAliveInSeconds = DecodeUnsignedShort(buffer, ref remainingLength);
var clientId = DecodeString(buffer, ref remainingLength);
Util.ValidateClientId(clientId);
packet.ClientId = clientId;
if (hasWill)
{
packet.WillTopicName = DecodeString(buffer, ref remainingLength);
var willMessageLength = DecodeUnsignedShort(buffer, ref remainingLength);
DecreaseRemainingLength(ref remainingLength, willMessageLength);
packet.WillMessage = buffer.ReadBytes(willMessageLength);
}
if (packet.HasUsername)
{
packet.Username = DecodeString(buffer, ref remainingLength);
}
if (packet.HasPassword)
{
packet.Password = DecodeString(buffer, ref remainingLength);
}
}