Java Requires Chilkat v11.0.0+

POP3 over Multiple Hop SSH

Demonstrates how to read POP3 email (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => POP3Server

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 POP3 server though the ssh2 tunnel (which itself is routed through ssh1).
        // The connection looks like this:  Application => ServerSSH1 => ServerSSH2 => POP3Server
        try {
            mailman.useSsh(ssh2);

            // Set the POP3 server's hostname
            mailman.setMailHost("pop.example.com");

            // Set the POP3 login/password.
            mailman.setPopUsername("myLogin");
            mailman.setPopPassword("myPassword");

            // Establish the POP3 connection through the ssh2 tunnel.
            mailman.pop3BeginSession();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Get the number of messages in the mailbox.
        int numMessages = mailman.getMailboxCount();

        Email email = new Email();
        int i = 1;
        while (i <= numMessages) {
            // Fetch by the message number (not by the UIDL)
            try {
                mailman.fetchOne(false, 0, i, email);
            } catch (ChilkatException e) {
                System.out.println(e.getLastErrorText());
                return;
            }

            System.out.println(email.getFrom() + ": " + email.getSubject() + "\n");

            i = i + 1;
        }

        // Close the connection with the POP3 server.  (This closes the tunnel through ssh2)
        // The connection with ssh2 is still alive, and may be used for more connections.
        mailman.pop3EndSession();

        // 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();
    }
}