Use the SOCKS5 Proxy Server to connect to the network

/// <Summary>
/// Use the SOCKS5 Proxy Server to connect to the network
/// </Summary>
Class sockproxy
{
Bool m_requireauthorize = false;
String m_user = string. empty;
String m_pass = string. empty;

/// <Summary>
/// Default is false
/// </Summary>
Public bool requireauthorize
{
Get {return m_requireauthorize ;}
Set {m_requireauthorize = value ;}
}
Public String Username
{
Get {return m_pass ;}
Set {m_pass = value ;}
}
Public String Password
{
Get {return m_user ;}
Set {m_user = value ;}
}

Public bool connectproxyserver (string strremotehost, int iremoteport, socket sproxyserver)
{
// Construct the first connection header of the SOCKS5 Proxy Server (no user name or password)
Byte [] bysock5send = new byte [10];
Bysock5send [0] = 5;
Bysock5send [1] = 1;
Bysock5send [2] = requireauthorize? (Byte) 2: (byte) 0;

// Send the first connection information of the SOCKS5 Proxy
Sproxyserver. Send (bysock5send, 3, socketflags. None );

Byte [] bysock5receive = new byte [10];
Int ireccount = sproxyserver. Receive (bysock5receive, bysock5receive. length, socketflags. None );

// User verification
If (bysock5receive [1] = 2 &&! Requireauthorize)
{
Throw new exception ("the proxy server requires Identity confirmation. ");
}
Else if (bysock5receive [1] = 2)
{
// Construct the first connection header of the SOCKS5 Proxy Server (no user name or password)
Byte [] Buser = encoding. Default. getbytes (username );
Byte [] bpass = encoding. Default. getbytes (password );

Int DL = 3 + Buser. Length + bpass. length;

Bysock5send = new byte [DL];
Bysock5send [0] = 5;
Bysock5send [1] = (byte) Buser. length;
Array. Copy (Buser, 0, bysock5send, 2, Buser. Length );
Bysock5send [2 + Buser. Length] = (byte) bpass. length;
Array. Copy (bpass, 0, bysock5send, 3 + Buser. length, bpass. Length );

// Send the first connection information of the SOCKS5 Proxy
Sproxyserver. Send (bysock5send, DL, socketflags. None );

Bysock5receive = new byte [100];
Ireccount = sproxyserver. Receive (bysock5receive, bysock5receive. length, socketflags. None );
}

If (ireccount <2)
{
Sproxyserver. Close ();
Throw new exception ("cannot get the correct response from the proxy server. ");
}

If (bysock5receive [0]! = 5 | (bysock5receive [1]! = 0 & bysock5receive [1]! = 2 ))
{
Sproxyserver. Close ();
Throw new exception ("the response error returned by the proxy service. ");
}

If (bysock5receive [1] = 0)
{
Bysock5send [0] = 5;
Bysock5send [1] = 1;
Bysock5send [2] = 0;
Bysock5send [3] = 1;

IPaddress ipadd = DNS. Resolve (strremotehost). Addresslist [0];
String strip = ipadd. tostring ();
String [] strarytemp = strip. Split (New char [] {'.'});
Bysock5send [4] = convert. tobyte (strarytemp [0]);
Bysock5send [5] = convert. tobyte (strarytemp [1]);
Bysock5send [6] = convert. tobyte (strarytemp [2]);
Bysock5send [7] = convert. tobyte (strarytemp [3]);

Bysock5send [8] = (byte) (iremoteport/256 );
Bysock5send [9] = (byte) (iremoteport % 256 );

Sproxyserver. Send (bysock5send, bysock5send. length, socketflags. None );
Ireccount = sproxyserver. Receive (bysock5receive, bysock5receive. length, socketflags. None );

If (bysock5receive [0]! = 5 | bysock5receive [1]! = 0)
{
Sproxyserver. Close ();
Throw new exception ("the second connection to the SOCKS5 Proxy returned data error. ");
}
Return true;
}

Else
{
If (bysock5receive [1] = 2)
Throw new exception ("the proxy server requires Identity confirmation. ");
Else
Return false;
}
Return false;
}

Public socket getsocket (string stripadd, int iport)
{
IPaddress hostadd = IPaddress. parse (stripadd); // DNS. Resolve (stripadd). Addresslist [0];
Ipendpoint ephost = new ipendpoint (hostadd, iport );
Socket S = new socket (addressfamily. InterNetwork, sockettype. Stream, protocoltype. TCP );
S. Connect (ephost );
Return S;
}
}
// Usage example:

Private void form1_load (Object sender, eventargs E)
{
String proxyhost = "10.32.32.51"; // "10.4.8.1 ";//
Int proxyprot = 1080;

Byte [] B;
Int RL = 0;
String SR;

Sockproxy P = new sockproxy ();

{// Skip this Code if password verification is not required
P. requireauthorize = true;
P. Username = "Jerry ";
P. Password = "456321 ";
}
Socket SRH = P. getsocket (proxyhost, proxyprot );

P. Fig ("10.32.9.16", 9160, SRH );
B = encoding. Default. getbytes ("Get/WAP/default. aspx HTTP/1.0 ");
SRH. Send (B );
B = new byte [2, 4096];
RL = SRH. Receive (B );
Sr = encoding. Default. getstring (B, 0, rl );
MessageBox. Show (SR );
}