private void HandshakeReceive()
{
try
{
var bytesRead = _firstPacketLength;
if (bytesRead > 1)
{
if ((!string.IsNullOrEmpty(_config.AuthUser) || IPSubnet.IsLoopBack(((IPEndPoint)_connection.RemoteEndPoint).Address)) &&
_firstPacket[0] == 4 && _firstPacketLength >= 9)
{
RspSocks4aHandshakeReceive();
}
else if (_firstPacket[0] == 5 && _firstPacketLength >= 3)
{
RspSocks5HandshakeReceive();
}
else
{
RspHttpHandshakeReceive();
}
}
else
{
Close();
}
}
catch (Exception e)
{
Logging.LogUsefulException(e);
Close();
}
}
public void IsLoopBackTest()
{
Assert.IsTrue(IPSubnet.IsLoopBack(IPAddress.Loopback));
Assert.IsTrue(IPSubnet.IsLoopBack(IPAddress.IPv6Loopback));
Assert.IsTrue(IPSubnet.IsLoopBack(IPAddress.Parse(@"127.0.0.255")));
Assert.IsTrue(IPSubnet.IsLoopBack(IPAddress.Parse(@"127.255.255.255")));
Assert.IsFalse(IPSubnet.IsLoopBack(IPAddress.Parse(@"192.168.1.1")));
Assert.IsFalse(IPSubnet.IsLoopBack(IPAddress.Parse(@"2001:0DB8:ABCD:0012:FFFF:FFFF:FFFF:FFFF")));
}
private bool AuthConnection(string authUser, string authPass)
{
if ((_config.AuthUser ?? string.Empty).Length == 0)
{
return(true);
}
if (_config.AuthUser == authUser && (_config.AuthPass ?? "") == authPass)
{
return(true);
}
return(IPSubnet.IsLoopBack(((IPEndPoint)_connection.RemoteEndPoint).Address));
}
private bool AuthConnection(string authUser, string authPass)
{
if (string.IsNullOrEmpty(_config.AuthUser))
{
return(true);
}
if (_config.AuthUser == authUser && _config.AuthPass == authPass)
{
return(true);
}
return(IPSubnet.IsLoopBack(((IPEndPoint)_connection.RemoteEndPoint).Address));
}
private void RspSocks5HandshakeReceive()
{
byte[] response = { 5, 0 };
if (_firstPacket[0] != 5)
{
response = new byte[] { 0, 91 };
Console.WriteLine(@"socks 4/5 protocol error");
_connection.Send(response);
Close();
return;
}
var auth = false;
var has_method = false;
for (var index = 0; index < _firstPacket[1]; ++index)
{
if (_firstPacket[2 + index] == 0)
{
has_method = true;
}
else if (_firstPacket[2 + index] == 2)
{
auth = true;
has_method = true;
}
}
if (!has_method)
{
Console.WriteLine(@"Socks5 no acceptable auth method");
Close();
return;
}
if (auth)
{
response[1] = 2;
_connection.BeginSend(response, 0, response.Length, SocketFlags.None, HandshakeAuthSendCallback, null);
}
else if (string.IsNullOrEmpty(_config.AuthUser) ||
IPSubnet.IsLoopBack(((IPEndPoint)_connection.RemoteEndPoint).Address))
{
_connection.BeginSend(response, 0, response.Length, SocketFlags.None, HandshakeSendCallback, null);
}
else
{
Console.WriteLine(@"Socks5 Auth failed");
Close();
}
}
public void Start(Configuration config, byte[] firstPacket, int length, Socket socket, int targetPort)
{
_config = config;
_firstPacket = firstPacket;
_firstPacketLength = length;
_local = socket;
_targetPort = targetPort;
if ((_config.AuthUser ?? string.Empty).Length == 0 ||
IPSubnet.IsLoopBack(((IPEndPoint)_local.RemoteEndPoint).Address))
{
Connect();
}
else
{
RspHttpHandshakeReceive();
}
}
private void RspHttpHandshakeReceive()
{
_command = 1; // Set TCP connect command
if (httpProxyState == null)
{
httpProxyState = new HttpParser();
}
if (IPSubnet.IsLoopBack(((IPEndPoint)_connection.RemoteEndPoint).Address))
{
httpProxyState.httpAuthUser = string.Empty;
httpProxyState.httpAuthPass = string.Empty;
}
else
{
httpProxyState.httpAuthUser = _config.AuthUser;
httpProxyState.httpAuthPass = _config.AuthPass;
}
for (var i = 1; ; ++i)
{
var err = httpProxyState.HandshakeReceive(_firstPacket, _firstPacketLength, out _remoteHeaderSendBuffer);
if (err == 1)
{
if (HttpHandshakeRecv())
{
break;
}
}
else if (err == 2)
{
var dataSend = HttpParser.Http407();
var httpData = Encoding.UTF8.GetBytes(dataSend);
_connection.Send(httpData);
if (HttpHandshakeRecv())
{
break;
}
}
else if (err is 3 or 4)
{
Connect();
break;
}