Java

SSH Tunnel Uncommon Options

Demonstrates the UncommonOptions property, which enables optional behavior for uncommon requirements. The default is an empty string; provide a comma-separated list of keywords to enable more than one option. Available keywords are listed in the reference documentation.

Background: This is a catch-all for narrow workarounds that do not warrant their own properties — forcing a specific signature algorithm, disabling the periodic keep-alive, removing weak MACs, bypassing a VPN on Android, and so on. Most applications never set it. When you do, it is usually to satisfy a particular server's quirk or a specific security requirement, and the exact keyword matters, so consult the documented list rather than guessing.

Chilkat Java Downloads

Download Chilkat for Java

Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.SshTunnel;

public class ChilkatExample {

    public static void main(String[] args) {
        // Demonstrates the SshTunnel.UncommonOptions property, which enables optional behavior for
        // uncommon requirements.  The default is an empty string, appropriate for most applications.
        // Provide a comma-separated list of keywords to enable more than one option.

        SshTunnel tunnel = new SshTunnel();

        // For example, disable the periodic keep-alive ignore message and remove weak MAC algorithms
        // from those offered.  Available keywords are listed in the reference documentation.
        tunnel.setUncommonOptions("NoKeepAliveIgnoreMsg,no-weak-mac-algs");

        tunnel.setDestHostname("db.internal.example.com");
        tunnel.setDestPort(5432);

        int sshPort = 22;
        try {
            tunnel.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 {
            tunnel.authenticatePw("mySshLogin", password);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        int listenPort = 1080;
        try {
            tunnel.beginAccepting(listenPort);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("Tunnel established.");

        boolean waitForThreadExit = true;
        try {
            tunnel.closeTunnel(waitForThreadExit);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }
    }
}