Java

Continue SSH Tunnel Keyboard-Interactive Authentication

Demonstrates the Chilkat SshTunnel.ContinueKeyboardAuth method, which submits a response to a keyboard-interactive prompt. The only argument is the response text; for a request with multiple prompts, an XML response is supplied instead. It returns XML indicating the next prompt or the final result.

Background: This is the second half of the exchange started by StartKeyboardAuth. A server may issue several rounds of prompts, so a robust client loops: submit answers, read the returned XML, and continue until it sees success or failure. On success, BeginAccepting still must be called before the tunnel forwards traffic.

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

public class ChilkatExample {

    public static void main(String[] args) {
        // Demonstrates the SshTunnel.ContinueKeyboardAuth method, which submits a response to a
        // keyboard-interactive prompt.  The only argument is the response.  For multiple prompts, an XML
        // response is supplied instead.

        SshTunnel tunnel = new SshTunnel();

        // The tunnel forwards accepted local connections to this destination through the SSH server.
        tunnel.setDestHostname("db.internal.example.com");
        tunnel.setDestPort(5432);

        // Connect to the SSH server.  This performs the TCP/proxy connection and SSH handshake, but
        // does not authenticate yet.
        int sshPort = 22;
        String infoRequestXml;
        try {
            tunnel.connect("ssh.example.com", sshPort);

            // Begin keyboard-interactive authentication to receive the server's prompt(s).
            infoRequestXml = tunnel.startKeyboardAuth("mySshLogin");
        } 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";

        // Submit the response (typically the password).  The returned XML indicates the next prompt or
        // the final result.
        String result;
        try {
            result = tunnel.continueKeyboardAuth(password);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println(result);

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