Dart

Use an Existing Socket SSH Tunnel

Demonstrates the Chilkat MailMan.UseSshTunnel method, which configures MailMan to use an existing SSH tunnel provided by a Socket object for its SMTP and POP3 connections. This example opens and authenticates a tunnel on a Socket, hands it to MailMan, and then verifies an SMTP login through it.

Background: Sharing one already-established SSH tunnel across objects avoids opening (and authenticating) a separate SSH connection for every component that needs to reach the remote network. Here the tunnel lives on a Socket object, which MailMan then routes its SMTP/POP3 traffic through. It is the Socket-based sibling of UseSsh, which shares an Ssh object instead.

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Dart

import 'package:chilkat/chilkat.dart';

void main() {
  var success = false;

  // Demonstrates the MailMan.UseSshTunnel method, which configures MailMan to use an existing
  // SSH tunnel provided by a Socket object for its SMTP and POP3 connections.

  // Open and authenticate the SSH tunnel using a Socket object.
  final sshTunnel = CkSocket();
  try {
    sshTunnel.sshOpenTunnel('ssh.example.com', 22);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  try {
    sshTunnel.sshAuthenticatePw('sshUser', 'sshPassword');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final mailman = CkMailMan();

  // Configure the SMTP server connection.  These connections will travel through the tunnel.
  mailman.smtpHost = 'smtp.example.com';
  mailman.smtpPort = 465;
  mailman.smtpSsl = true;
  mailman.smtpUsername = 'user@example.com';
  mailman.smtpPassword = 'myPassword';

  // Tell MailMan to route its connections through the existing tunnel.
  try {
    mailman.useSshTunnel(sshTunnel);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // SMTP operations now travel through the shared SSH tunnel.
  success = mailman.verifySmtpLogin();
  if (!success) {
    print(mailman.lastErrorText);
    return;
  }

  print('Authenticated with the SMTP server through the SSH tunnel.');
}