Java

SMTP over Multiple Hop SSH

Demonstrates how to send email (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => SmtpServer

The ConnectThroughSsh and UseSsh methods are added in Chilkat version 9.5.0.55 to accomplish this task.

Chilkat2 Java

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

public class ChilkatExample {

    public static void main(String[] args) {
        // This example requires the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        Ssh ssh1 = new Ssh();

        // Connect directly to the 1st SSH server.
        try {
            ssh1.connect("serverssh1.com", 22);

            // Authenticate using login/password:
            ssh1.authenticatePw("ssh1Login", "ssh1Password");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            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.
        Ssh ssh2 = new Ssh();
        try {
            ssh2.connectThroughSsh(ssh1, "serverssh2.com", 22);

            // Authenticate with ssh2...
            ssh2.authenticatePw("ssh2Login", "ssh2Password");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        MailMan mailman = new MailMan();

        // Tell the mailman object to connect to the SMTP server though the ssh2 tunnel (which itself is routed through ssh1).
        // The connection looks like this:  Application => ServerSSH1 => ServerSSH2 => SMTPServer
        try {
            mailman.useSsh(ssh2);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Set the SMTP server.
        mailman.setSmtpHost("smtp.someserver.com");

        // Set the SMTP login/password (if required)
        mailman.setSmtpUsername("myUsername");
        mailman.setSmtpPassword("myPassword");

        // Create a new email object
        Email email = new Email();

        email.setSubject("This is a test");
        email.setBody("This is a test");
        email.setFrom("Chilkat Support <support@chilkatsoft.com>");
        email.addTo("Chilkat Admin", "admin@chilkatsoft.com");

        try {
            mailman.sendEmail(email);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Close the connection with the server.  This closes the tunnel through ssh2.
        try {
            mailman.closeSmtpConnection();
        } catch (ChilkatException e) {
            System.out.println("Connection to SMTP server not closed cleanly.");
        }

        System.out.println("Mail Sent!");

        // 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();
    }
}