Java

Request SSH X11 Forwarding

Demonstrates the Chilkat Ssh.SendReqX11Forwarding method, which sends an X11-forwarding request on a session channel. The arguments are the channel number, whether forwarding is limited to a single connection, and the X11 authentication protocol, cookie, and screen number.

Background: X11 forwarding lets a graphical program running on the remote host display its window on your local machine, tunneled over SSH. This is a low-level method that only sends the protocol request — your application is still responsible for the local X server side of the arrangement. The authentication cookie guards the forwarded display, so it should be a freshly generated value rather than a fixed constant.

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Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    //  Demonstrates the Ssh.SendReqX11Forwarding method, which sends an SSH X11-forwarding request
    //  on a session channel.  The 1st argument is the channel number, the 2nd limits forwarding to a
    //  single connection, and the 3rd through 5th supply the X11 authentication protocol, cookie,
    //  and screen number.

    CkSsh ssh = new CkSsh();

    int sshPort = 22;
    success = ssh.Connect("ssh.example.com",sshPort);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    //  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.
    String password = "mySshPassword";

    success = ssh.AuthenticatePw("mySshLogin",password);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    //  Open a session channel.  A negative return value indicates failure.
    int channelNum = ssh.OpenSessionChannel();
    if (channelNum < 0) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    //  Request X11 forwarding.  Named variables make each argument's meaning clear.
    boolean singleConnection = false;
    String authProt = "MIT-MAGIC-COOKIE-1";
    String authCookie = "d92f5e1a7c8b4306af17c2e5b9d43081";
    int screenNum = 0;
    success = ssh.SendReqX11Forwarding(channelNum,singleConnection,authProt,authCookie,screenNum);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    System.out.println("X11 forwarding requested.");

    ssh.Disconnect();
  }
}