public void Start()
{
DoAsyncRead();
if (SocksVersion == 4)
{
MethodSelectionsVersionFourMessage msg = new MethodSelectionsVersionFourMessage();
msg.SOCKS4CommandCode = SOCKS4CommandCode.TCPStream;
msg.DomainName = RemoteHost;
msg.DestinationPort = (ushort)RemotePort;
msg.UserId = User;
msg.Version = 0x04;
byte[] bMsg = msg.GetBytes();
Send(bMsg);
}
else if (SocksVersion == 5)
{
SOCKS5ClientSessionState = SOCKS5ClientSessionState.WaitingForMethodSelected;
MethodSelectionsMessage msg = new MethodSelectionsMessage();
msg.Version = 0x05;
msg.Methods.Add(SockMethod.NoAuthenticationRequired);
byte[] bMsg = msg.GetBytes();
Send(bMsg);
}
else
{
}
}
protected override void OnRecvData(byte[] bData, int nLen)
{
if (nLen == 0)
{
OnDisconnect("Normal closing");
return;
}
if (ServerSessionState == ServerSessionState.Forwarding)
{
try
{
if (ConnectClient != null) /// connected client may be null if we are acting as a socks5 bytestream proxy, where we don't actually forward anything
{
ConnectClient.Send(bData, nLen);
}
DoAsyncRead();
}
catch (Exception)
{ }
return;
}
ReceiveBuffer.AppendData(bData, 0, nLen);
if (ServerSessionState == ServerSessionState.JustExisting)
{
DoAsyncRead(); // go read some more
return;
}
byte[] bCurData = ReceiveBuffer.PeekAllSamples();
if (bCurData.Length <= 0)
{
DoAsyncRead();
return;
}
if (ServerSessionState == ServerSessionState.WaitingForMethodSelections)
{
int nVersion = bCurData[0];
if (nVersion == 5)
{
MethodSelectionsMessage msg = new MethodSelectionsMessage();
int nRead = msg.ReadFromBytes(bData, 0);
if (nRead > 0)
{
ReceiveBuffer.GetNSamples(nRead);
/// Determine which method we support
///
bool bCanDoNoAuth = false;
foreach (SockMethod method in msg.Methods)
{
if (method == SockMethod.NoAuthenticationRequired)
{
bCanDoNoAuth = true;
break;
}
}
if (bCanDoNoAuth == false)
{
MethodSelectedMessage retmsg = new MethodSelectedMessage();
retmsg.Version = 5;
retmsg.SockMethod = SockMethod.NoAcceptableMethods;
this.Send(retmsg.GetBytes());
this.Disconnect();
return;
}
else
{
ServerSessionState = ServerSessionState.WaitingForSocksRequestMessage;
MethodSelectedMessage retmsg = new MethodSelectedMessage();
retmsg.Version = msg.Version;
retmsg.SockMethod = SockMethod.NoAuthenticationRequired;
this.Send(retmsg.GetBytes());
}
}
}
else if (nVersion == 4)
{
MethodSelectionsVersionFourMessage msg = new MethodSelectionsVersionFourMessage();
int nRead = msg.ReadFromBytes(bData, 0);
if (nRead > 0)
{
ReceiveBuffer.GetNSamples(nRead);
MethodSelectedVersionFourMessage reply = new MethodSelectedVersionFourMessage();
/// See what the man wants. It appears that mozilla immediately starts sending data if we return success here, so let's do it
///
this.ServerSessionState = ServerSessionState.Forwarding;
/// Let's try to connect
///
bool bConnected = false;
if (msg.DomainName != null)
{
bConnected = ConnectClient.Connect(msg.DomainName, msg.DestinationPort, true);
}
else
{
bConnected = ConnectClient.Connect(msg.DestIPAddress.ToString(), msg.DestinationPort, true);
}
if (bConnected == false)
{
reply.SOCKS4Status = SOCKS4Status.RequestRejected;
Send(reply.GetBytes());
Disconnect();
}
else
{
reply.SOCKS4Status = SOCKS4Status.RequestGranted;
Send(reply.GetBytes());
}
}
}
else
{
Console.WriteLine("Version {0} not supported", nVersion);
MethodSelectedMessage retmsg = new MethodSelectedMessage();
retmsg.Version = 5;
retmsg.SockMethod = SockMethod.NoAcceptableMethods;
this.Send(retmsg.GetBytes());
this.Disconnect();
return;
}
}
else if (ServerSessionState == ServerSessionState.WaitingForSocksRequestMessage)
{
/// Read in our SocksRequestMessage
///
SocksRequestMessage reqmsg = new SocksRequestMessage();
int nRead = reqmsg.ReadFromBytes(bData, 0);
if (nRead > 0)
{
ReceiveBuffer.GetNSamples(nRead);
if (reqmsg.Version != 0x05)
{
Console.WriteLine("No version 5, client wants version: {0}", reqmsg.Version);
}
//Parent.HandleRequest(reqmsg, this);
if (reqmsg.SOCKSCommand == SOCKSCommand.Connect)
{
/// See what the man wants. It appears that mozilla immediately starts sending data if we return success here, so let's do it
///
bool bConnected = false;
if (SOCKSServerMode == SOCKSServerMode.NormalSOCKS5Server)
{
this.ServerSessionState = ServerSessionState.Forwarding;
/// Let's try to connect
///
if (reqmsg.AddressType == AddressType.DomainName)
{
bConnected = ConnectClient.Connect(reqmsg.DestinationDomain, reqmsg.DestinationPort, true);
}
else
{
bConnected = ConnectClient.Connect(reqmsg.DestinationAddress.ToString(), reqmsg.DestinationPort, true);
}
}
else
{
Console.WriteLine("Incoming SOCKS5 Bytestream Connect command to domain: {0}, remote endppoint is: {1}", reqmsg.DestinationDomain, this.socket.RemoteEndPoint);
RemoteHost = reqmsg.DestinationDomain;
bConnected = true;
this.ServerSessionState = ServerSessionState.JustExisting;
}
SocksReplyMessage reply = new SocksReplyMessage();
if (bConnected == false)
{
reply.SOCKSReply = SOCKSReply.ConnectionRefused;
}
else
{
reply.SOCKSReply = SOCKSReply.Succeeded;
}
Send(reply.GetBytes());
}
else
{
SocksReplyMessage reply = new SocksReplyMessage();
reply.SOCKSReply = SOCKSReply.CommandNotSupported;
reply.AddressType = AddressType.IPV4;
Send(reply.GetBytes());
}
}
}
DoAsyncRead(); // go read some more
}