(Perl) 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 Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

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

$ssh1 = chilkat::CkSsh->new();

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

# Authenticate using login/password:
$success = $ssh1->AuthenticatePw("ssh1Login","ssh1Password");
if ($success != 1) {
    print $ssh1->lastErrorText() . "\r\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 = chilkat::CkSsh->new();
$success = $ssh2->ConnectThroughSsh($ssh1,"serverssh2.com",22);
if ($success != 1) {
    print $ssh2->lastErrorText() . "\r\n";
    exit;
}

# Authenticate with ssh2...
$success = $ssh2->AuthenticatePw("ssh2Login","ssh2Password");
if ($success != 1) {
    print $ssh2->lastErrorText() . "\r\n";
    exit;
}

$mailman = chilkat::CkMailMan->new();

# 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 != 1) {
    print $mailman->lastErrorText() . "\r\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 = chilkat::CkEmail->new();

$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 != 1) {
    print $mailman->lastErrorText() . "\r\n";
    exit;
}

# Close the connection with the server.  This closes the tunnel through ssh2.
$success = $mailman->CloseSmtpConnection();
if ($success != 1) {
    print "Connection to SMTP server not closed cleanly." . "\r\n";
}

print "Mail Sent!" . "\r\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();