public int FillTrojanRequest(Span <byte> data, Destination.Destination destination, bool isUdpPayload = false, ushort udpPayloadSize = 0)
{
Span <byte> crlf = stackalloc byte[2];
crlf[0] = 0x0D;
crlf[1] = 0x0A;
int len = 0;
if (!isUdpPayload)
{
hashedPassword.Span.CopyTo(data);
len += hashedPassword.Length;
crlf.CopyTo(data.Slice(len, 2));
len += crlf.Length;
switch (destination.TransportProtocol)
{
case TransportProtocol.Tcp:
data[len++] = 1;
break;
case TransportProtocol.Udp:
data[len++] = 3;
break;
}
}
len += destination.FillSocks5StyleAddress(data.Slice(len));
if (isUdpPayload)
{
data[len++] = (byte)(udpPayloadSize >> 8);
data[len++] = (byte)(udpPayloadSize & 0xFF);
}
crlf.CopyTo(data.Slice(len));
len += 2;
return(len);
}
public async void SendPacketToRemote(Memory <byte> data, Destination.Destination destination)
{
try
{
await udpSendLock.WaitAsync().ConfigureAwait(false);
}
catch (NullReferenceException)
{
return;
}
catch (ObjectDisposedException)
{
return;
}
var udpSendBuffer = sendArrayPool.Rent(destination.Host.Size + data.Length + 4);
var udpSendEncBuffer = sendArrayPool.Rent(destination.Host.Size + data.Length + 52);
try
{
// TODO: avoid copy
var headerLen = destination.FillSocks5StyleAddress(udpSendBuffer);
data.Span.CopyTo(udpSendBuffer.AsSpan(headerLen));
var cryptor = ShadowsocksFactory.GlobalCryptorFactory.CreateCryptor();
var ivLen = Encrypt(Array.Empty <byte>(), udpSendEncBuffer, cryptor); // Fill IV/Salt first
var len = EncryptAll(udpSendBuffer.AsSpan(0, headerLen + data.Length), udpSendEncBuffer.AsSpan((int)ivLen), cryptor);
_ = udpOutputStream.WriteAsync(udpSendEncBuffer.AsBuffer(0, (int)(len + ivLen)));
}
finally
{
try
{
udpSendLock.Release();
}
catch (ObjectDisposedException) { }
sendArrayPool.Return(udpSendBuffer);
sendArrayPool.Return(udpSendEncBuffer);
}
}