Unicode C

SSH Through a SOCKS Proxy

Demonstrates connecting to an SSH server through a SOCKS4 or SOCKS5 proxy. Set the SOCKS properties before calling Connect, and set SocksVersion to match the proxy server.

Background: SOCKS is a general-purpose TCP relay, so unlike an HTTP proxy it is designed from the start to carry arbitrary protocols — usually the smoother option for SSH. The version matters: SOCKS4 supports only a username with no password, while SOCKS5 supports full login/password authentication as well as IPv6 and remote DNS resolution. Note this is the inverse of dynamic port forwarding: here a SOCKS proxy is used to reach the SSH server, rather than SSH providing a SOCKS proxy.

Chilkat Unicode C Downloads

Download Chilkat for Unicode C

Unicode C

#include <C_CkSshW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkSshW ssh;
    const wchar_t *hostname;
    int port;
    const wchar_t *password;

    success = FALSE;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  Demonstrates connecting to an SSH server through a SOCKS4 or SOCKS5 proxy.

    ssh = CkSshW_Create();

    //  Set the SOCKS proxy properties before connecting.  The hostname may be a domain name or an
    //  IP address.
    CkSshW_putSocksHostname(ssh,L"socks.example.com");
    CkSshW_putSocksPort(ssh,1080);
    CkSshW_putSocksUsername(ssh,L"mySocksLogin");
    CkSshW_putSocksPassword(ssh,L"mySocksPassword");

    //  Set the version to match the proxy server: 4 or 5.
    //  Note: SOCKS4 supports only a username, with no password.  SOCKS5 supports full
    //  login/password authentication.
    CkSshW_putSocksVersion(ssh,5);

    hostname = L"ssh.example.com";
    port = 22;
    success = CkSshW_Connect(ssh,hostname,port);
    if (success == FALSE) {
        wprintf(L"%s\n",CkSshW_lastErrorText(ssh));
        CkSshW_Dispose(ssh);
        return;
    }

    wprintf(L"Connected to the SSH server through the SOCKS proxy.\n");

    //  Normally you would not hard-code the password in source.  You should instead obtain it
    //  from an interactive prompt, environment variable, or a secrets vault.
    password = L"mySshPassword";

    success = CkSshW_AuthenticatePw(ssh,L"mySshLogin",password);
    if (success == FALSE) {
        wprintf(L"%s\n",CkSshW_lastErrorText(ssh));
        CkSshW_Dispose(ssh);
        return;
    }

    //  ... use the SSH connection normally ...

    CkSshW_Disconnect(ssh);


    CkSshW_Dispose(ssh);

    }