public void SendPacket(ushort type, byte[] data)
{
if (_connected == 0)
{
throw new Exception();
}
_sendLock.Wait(); try {
if (_sent == 0 && _encrypted && _sending == 0 /* if sending we've already done this */)
{
Random random = new Random();
_sendBuffer[_sendOffset++] = 0x0B;
int prefix = random.Next() % 64;
for (int i = 0; i < prefix; i++)
{
_sendBuffer[_sendOffset++] = (byte)(random.Next() % 256);
}
_sendBuffer[_sendOffset++] = 0xFF;
for (int i = 0; i < 16; i++)
{
_sendBuffer[_sendOffset++] = (byte)(random.Next() % 256);
}
byte[] seed = new byte[16];
Array.Copy(_sendBuffer, _sendOffset - 16, seed, 0, 16);
Console.WriteLine("send seed {0} for {1} --> {2}", Formatter.FormatKey(seed), _socket.LocalEndPoint, _socket.RemoteEndPoint);
int length = prefix + 1 + 16;
_sendCrypt.Process(_sendBuffer, _sendOffset - length, length);
_sendCrypt.SetSeed(seed);
}
if (_sendBuffer.Length - _sendOffset < 4 + data.Length)
{
throw new Exception(); // TODO: fix me
}
_sendCrypt.Process(BitConverter.GetBytes(type), 0, _sendBuffer, _sendOffset, sizeof(ushort));
_sendOffset += 2;
_sendCrypt.Process(BitConverter.GetBytes((ushort)data.Length), 0, _sendBuffer, _sendOffset, sizeof(ushort));
_sendOffset += 2;
_sendCrypt.Process(data, 0, _sendBuffer, _sendOffset, data.Length);
_sendOffset += data.Length;
if (Interlocked.CompareExchange(ref _sending, 1, 0) == 0)
{
_sendArgs.SetBuffer(_sendBuffer, 0, _sendOffset);
if (!_socket.SendAsync(_sendArgs))
{
Task.Run(() => { ProcessSend(_socket, _sendArgs); });
}
}
} finally { _sendLock.Release(); }
}
void ProcessReceive(object sender, SocketAsyncEventArgs e)
{
if (e.SocketError != SocketError.Success || e.BytesTransferred <= 0)
{
Disconnect(); return;
}
int received = e.BytesTransferred;
int offset = _recvOffset;
_recvOffset += received;
if (_received == 0 && _recvBuffer[offset] == 0x0B)
{
if (!_encrypted)
{
_encrypted = true;
InitializeCrypts();
}
offset++;
}
if (_encrypted && _recvCryptSeedCount < 16)
{
while (_recvCryptSeedCount == -1 && offset < _recvOffset)
{
_recvCrypt.Process(_recvBuffer, offset, 1);
if (_recvBuffer[offset++] == 0xFF)
{
_recvCryptSeedCount = 0;
}
}
if (_recvCryptSeedCount < 16 && offset < _recvOffset)
{
int count = Math.Min(_recvOffset - offset, 16 - _recvCryptSeedCount);
_recvCrypt.Process(_recvBuffer, offset, count);
_recvCryptSeedCount += count; offset += count;
}
if (_recvCryptSeedCount < 16)
{
_received += received;
e.SetBuffer(_recvOffset, _recvBuffer.Length - _recvOffset);
if (!_socket.ReceiveAsync(_recvArgs))
{
Task.Run(() => { ProcessReceive(_socket, _recvArgs); });
}
return;
}
Console.WriteLine("recv seed {0} for {1} <-- {2}", Formatter.FormatKey(_recvBuffer, offset - 16, 16), _socket.LocalEndPoint, _socket.RemoteEndPoint);
_recvCrypt.SetSeed(_recvBuffer, offset - 16);
_recvOffset -= offset;
Array.Copy(_recvBuffer, offset, _recvBuffer, 0, _recvOffset);
offset = 0;
}
_recvCrypt.Process(_recvBuffer, offset, _recvOffset - offset);
offset = 0;
while (_recvOffset - offset >= 4)
{
ushort packetType = BitConverter.ToUInt16(_recvBuffer, offset);
ushort packetLength = BitConverter.ToUInt16(_recvBuffer, offset + 2);
if (_recvOffset - offset < 4 + packetLength)
{
break;
}
OnPacket(new PacketEventArgs(_recvBuffer, offset, 4 + packetLength));
offset += 4 + packetLength;
}
_recvOffset -= offset;
Array.Copy(_recvBuffer, offset, _recvBuffer, 0, _recvOffset);
_received += received;
e.SetBuffer(_recvOffset, _recvBuffer.Length - _recvOffset);
if (!_socket.ReceiveAsync(_recvArgs))
{
Task.Run(() => { ProcessReceive(_socket, _recvArgs); });
}
}
