(PHP Extension) 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.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

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

$ssh1 = new CkSsh();

// Connect directly to the 1st SSH server.
$success = $ssh1->Connect('serverssh1.com',22);
if ($success != true) {
    print $ssh1->lastErrorText() . "\n";
    exit;
}

// Authenticate using login/password:
$success = $ssh1->AuthenticatePw('ssh1Login','ssh1Password');
if ($success != true) {
    print $ssh1->lastErrorText() . "\n";
    exit;
}

// 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.
$ssh2 = new CkSsh();
$success = $ssh2->ConnectThroughSsh($ssh1,'serverssh2.com',22);
if ($success != true) {
    print $ssh2->lastErrorText() . "\n";
    exit;
}

// Authenticate with ssh2...
$success = $ssh2->AuthenticatePw('ssh2Login','ssh2Password');
if ($success != true) {
    print $ssh2->lastErrorText() . "\n";
    exit;
}

$mailman = new CkMailMan();

// 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
$success = $mailman->UseSsh($ssh2);
if ($success != true) {
    print $mailman->lastErrorText() . "\n";
    exit;
}

// Set the SMTP server.
$mailman->put_SmtpHost('smtp.someserver.com');

// Set the SMTP login/password (if required)
$mailman->put_SmtpUsername('myUsername');
$mailman->put_SmtpPassword('myPassword');

// Create a new email object
$email = new CkEmail();

$email->put_Subject('This is a test');
$email->put_Body('This is a test');
$email->put_From('Chilkat Support <support@chilkatsoft.com>');
$success = $email->AddTo('Chilkat Admin','admin@chilkatsoft.com');

$success = $mailman->SendEmail($email);
if ($success != true) {
    print $mailman->lastErrorText() . "\n";
    exit;
}

// Close the connection with the server.  This closes the tunnel through ssh2.
$success = $mailman->CloseSmtpConnection();
if ($success != true) {
    print 'Connection to SMTP server not closed cleanly.' . "\n";
}

print 'Mail Sent!' . "\n";

// 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();

?>