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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import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Ssh;

public class ChilkatExample {

    public static void main(String[] args) {
        // 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.

        Ssh ssh = new Ssh();

        int sshPort = 22;
        try {
            ssh.connect("ssh.example.com", sshPort);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            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";

        try {
            ssh.authenticatePw("mySshLogin", password);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Open a session channel.  A negative return value indicates failure.
        int channelNum = ssh.openSessionChannel();
        if (channelNum < 0) {
            System.out.println(ssh.getLastErrorText());
            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;
        try {
            ssh.sendReqX11Forwarding(channelNum, singleConnection, authProt, authCookie, screenNum);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

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

        ssh.disconnect();
    }
}