(Java) Multi-Hop SSH (SSH Through SSH)

Demonstrates how to SSH through one SSH server to get to another SSH server. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2

The ConnectThroughSsh method is added in Chilkat version 9.5.0.55 to accomplish this task. Technically, it should be possible to chain any number of servers using the ConnectThroughSsh multiple times:

Application => ServerSSH1 => ServerSSH2 ==> ServerSSH3 => ... => ServerSSHN

Chilkat Java Downloads Java Libs for Windows, MacOS, Linux, Alpine Linux, Solaris Java Libs for Android

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[])
  {
    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkSsh ssh1 = new CkSsh();

    // Hostname may be an IP address or domain name:
    String hostname = "192.168.1.108";
    String port = 22;

    // Connect directly to the 1st SSH server:
    boolean success = ssh1.Connect(hostname,port);
    if (success != true) {
        System.out.println(ssh1.lastErrorText());
        return;
        }

    // Wait a max of 15 seconds when reading responses..
    ssh1.put_IdleTimeoutMs(15000);

    // Authenticate using login/password:
    success = ssh1.AuthenticatePw("myLogin","myPassword");
    if (success != true) {
        System.out.println(ssh1.lastErrorText());
        return;
        }

    // Connect through the 1st SSH connection to reach a 2nd SSH server.
    // Note: Any number of SSH connections may be simultaneously tunneled through a single
    // existing SSH connection.
    CkSsh ssh2 = new CkSsh();
    success = ssh2.ConnectThroughSsh(ssh1,"someremoteserver.com",22);
    if (success != true) {
        System.out.println(ssh2.lastErrorText());
        return;
        }

    ssh2.put_IdleTimeoutMs(15000);

    // Authenticate with ssh2...
    success = ssh2.AuthenticatePw("myLogin2","myPassword2");
    if (success != true) {
        System.out.println(ssh2.lastErrorText());
        return;
        }

    // The application may now is connected and authenticated with ssh2.
    // The application can do whatever it desires just as if it was directly
    // connected to ssh2.   For example, the application might open
    // a session channel to send commands or start a remote shell..
    int channelNum = ssh2.OpenSessionChannel();
    if (channelNum < 0) {
        System.out.println(ssh2.lastErrorText());
        return;
        }

    // ...
    // ...
    // ...

    // Close the connection with ssh2.  (This closes the the tunnel through ssh1.)
    // The connection with ssh1 is still alive, and may be used for more connections.
    ssh2.Disconnect();

    // ...
    // ...
    // ...

    ssh1.Disconnect();
  }
}