C++

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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C++

#include <CkSsh.h>

void ChilkatSample(void)
    {
    bool 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;

    int sshPort = 22;
    success = ssh.Connect("ssh.example.com",sshPort);
    if (success == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        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.
    const char *password = "mySshPassword";

    success = ssh.AuthenticatePw("mySshLogin",password);
    if (success == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        return;
    }

    //  Open a session channel.  A negative return value indicates failure.
    int channelNum = ssh.OpenSessionChannel();
    if (channelNum < 0) {
        std::cout << ssh.lastErrorText() << "\r\n";
        return;
    }

    //  Request X11 forwarding.  Named variables make each argument's meaning clear.
    bool singleConnection = false;
    const char *authProt = "MIT-MAGIC-COOKIE-1";
    const char *authCookie = "d92f5e1a7c8b4306af17c2e5b9d43081";
    int screenNum = 0;
    success = ssh.SendReqX11Forwarding(channelNum,singleConnection,authProt,authCookie,screenNum);
    if (success == false) {
        std::cout << ssh.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "X11 forwarding requested." << "\r\n";

    ssh.Disconnect();
    }