Форум на Исходниках.RU

using System;

using System.Net;

using System.Net.Sockets;

using System.Text;

* zahmed

* Date 23 Jan 2004

* Socks 5 RFC is available at http://www.faqs.org/rfcs/rfc1928.html.

namespace LMKR

{

public class ConnectionException:ApplicationException

{

public ConnectionException(string message)

:base(message)

{

}

/// <summary>

/// Provides sock5 functionality to clients (Connect only).

/// </summary>

public class SocksProxy

{

private SocksProxy(){}

#region ErrorMessages

private static string[] errorMsgs= {

"Operation completed successfully.",

"General SOCKS server failure.",

"Connection not allowed by ruleset.",

"Network unreachable.",

"Host unreachable.",

"Connection refused.",

"TTL expired.",

"Command not supported.",

"Address type not supported.",

"Unknown error."

};

#endregion

public static Socket ConnectToSocks5Proxy(string proxyAdress, ushort proxyPort, string destAddress, ushort destPort,

string userName, string password)

{

IPAddress destIP = null;

IPAddress proxyIP = null;

byte[] request = new byte[257];

byte[] response = new byte[257];

ushort nIndex;

try

{

proxyIP = IPAddress.Parse(proxyAdress);

}

catch(FormatException)

{ // get the IP address

proxyIP = Dns.GetHostByAddress(proxyAdress).AddressList[0];

}

// Parse destAddress (assume it in string dotted format "212.116.65.112" )

try

{

destIP = IPAddress.Parse(destAddress);

}

catch(FormatException)

{

// wrong assumption its in domain name format "www.microsoft.com"

}

IPEndPoint proxyEndPoint = new IPEndPoint(proxyIP,proxyPort);

// open a TCP connection to SOCKS server...

Socket s = new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);

s.Connect(proxyEndPoint);

nIndex = 0;

request[nIndex++]=0x05; // Version 5.

request[nIndex++]=0x02; // 2 Authentication methods are in packet...

request[nIndex++]=0x00; // NO AUTHENTICATION REQUIRED

request[nIndex++]=0x02; // USERNAME/PASSWORD

// Send the authentication negotiation request...

s.Send(request,nIndex,SocketFlags.None);

// Receive 2 byte response...

int nGot = s.Receive(response,2,SocketFlags.None);

if (nGot!=2)

throw new ConnectionException("Bad response received from proxy server.");

if (response[1]==0xFF)

{ // No authentication method was accepted close the socket.

s.Close();

throw new ConnectionException("None of the authentication method was accepted by proxy server.");

}

byte[] rawBytes;

if (/*response[1]==0x02*/true)

{//Username/Password Authentication protocol

nIndex = 0;

request[nIndex++]=0x05; // Version 5.

// add user name

request[nIndex++]=(byte)userName.Length;

rawBytes = Encoding.Default.GetBytes(userName);

rawBytes.CopyTo(request,nIndex);

nIndex+=(ushort)rawBytes.Length;

// add password

request[nIndex++]=(byte)password.Length;

rawBytes = Encoding.Default.GetBytes(password);

rawBytes.CopyTo(request,nIndex);

nIndex+=(ushort)rawBytes.Length;

// Send the Username/Password request

s.Send(request,nIndex,SocketFlags.None);

// Receive 2 byte response...

nGot = s.Receive(response,2,SocketFlags.None);

if (nGot!=2)

throw new ConnectionException("Bad response received from proxy server.");

if (response[1] != 0x00)

throw new ConnectionException("Bad Usernaem/Password.");

}

// This version only supports connect command.

// UDP and Bind are not supported.

// Send connect request now...

nIndex = 0;

request[nIndex++]=0x05; // version 5.

request[nIndex++]=0x01; // command = connect.

request[nIndex++]=0x00; // Reserve = must be 0x00

if (destIP != null)

{// Destination adress in an IP.

switch(destIP.AddressFamily)

{

case AddressFamily.InterNetwork:

// Address is IPV4 format

request[nIndex++]=0x01;

rawBytes = destIP.GetAddressBytes();

rawBytes.CopyTo(request,nIndex);

nIndex+=(ushort)rawBytes.Length;

break;

case AddressFamily.InterNetworkV6:

// Address is IPV6 format

request[nIndex++]=0x04;

rawBytes = destIP.GetAddressBytes();

rawBytes.CopyTo(request,nIndex);

nIndex+=(ushort)rawBytes.Length;

break;

}

else

{// Dest. address is domain name.

request[nIndex++]=0x03; // Address is full-qualified domain name.

request[nIndex++]=Convert.ToByte(destAddress.Length); // length of address.

rawBytes = Encoding.Default.GetBytes(destAddress);

rawBytes.CopyTo(request,nIndex);

nIndex+=(ushort)rawBytes.Length;

}

// using big-edian byte order

byte[] portBytes = BitConverter.GetBytes(destPort);

for (int i=portBytes.Length-1;i>=0;i--)

request[nIndex++]=portBytes[i];

// send connect request.

s.Send(request,nIndex,SocketFlags.None);

s.Receive(response); // Get variable length response...

if (response[1]!=0x00)

throw new ConnectionException(errorMsgs[response[1]]);

// Success Connected...

return s;

}