(Node.js) 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

Note: This example requires Chilkat v11.0.0 or greater.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOS

var os = require('os');
if (os.platform() == 'win32') {  
  var chilkat = require('@chilkat/ck-node23-win64'); 
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node23-linux-arm');
    } else if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node23-linux-arm64');
    } else {
        var chilkat = require('@chilkat/ck-node23-linux-x64');
    }
} else if (os.platform() == 'darwin') {
  var chilkat = require('@chilkat/ck-node23-mac-universal');
}

function chilkatExample() {

    var success = false;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var ssh1 = new chilkat.Ssh();

    // Connect directly to the 1st SSH server.
    success = ssh1.Connect("serverssh1.com",22);
    if (success == false) {
        console.log(ssh1.LastErrorText);
        return;
    }

    // Authenticate using login/password:
    success = ssh1.AuthenticatePw("ssh1Login","ssh1Password");
    if (success == false) {
        console.log(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.
    var ssh2 = new chilkat.Ssh();
    success = ssh2.ConnectThroughSsh(ssh1,"serverssh2.com",22);
    if (success == false) {
        console.log(ssh2.LastErrorText);
        return;
    }

    // Authenticate with ssh2...
    success = ssh2.AuthenticatePw("ssh2Login","ssh2Password");
    if (success == false) {
        console.log(ssh2.LastErrorText);
        return;
    }

    var mailman = new chilkat.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
    success = mailman.UseSsh(ssh2);
    if (success == false) {
        console.log(mailman.LastErrorText);
        return;
    }

    // Set the POP3 server's hostname
    mailman.MailHost = "pop.example.com";

    // Set the POP3 login/password.
    mailman.PopUsername = "myLogin";
    mailman.PopPassword = "myPassword";

    // Establish the POP3 connection through the ssh2 tunnel.
    success = mailman.Pop3BeginSession();
    if (success == false) {
        console.log(mailman.LastErrorText);
        return;
    }

    // Get the number of messages in the mailbox.
    var numMessages = mailman.GetMailboxCount();

    var email = new chilkat.Email();
    var i = 1;
    while (i <= numMessages) {
        // Fetch by the message number (not by the UIDL)
        success = mailman.FetchOne(false,0,i,email);
        if (success == false) {
            console.log(mailman.LastErrorText);
            return;
        }

        console.log(email.From + ": " + email.Subject + "\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.
    success = 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();

}

chilkatExample();