Perl Requires Chilkat v11.0.0+

IMAP Use Existing SSH Tunnel

Demonstrates how to connect to an IMAP server using an existing SSH tunnel. This creates a new channel within the SSH tunnel, which can be a TCP or TLS connection, and is connected to a remote IMAP server through port forwarding. Perl

use chilkat();

$success = 0;

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

$tunnel = chilkat::CkSocket->new();

$sshHostname = "sftp.example.com";
$sshPort = 22;

#  Connect to an SSH server and establish the SSH tunnel:
$success = $tunnel->SshOpenTunnel($sshHostname,$sshPort);
if ($success == 0) {
    print $tunnel->lastErrorText() . "\r\n";
    exit;
}

#  Authenticate with the SSH server via a login/password
#  or with a public key.  
#  This example demonstrates SSH password authentication.
#  Note: This is not authenticating with the IMAP server, it is
#  for authenticating with the SSH server, which is separate.
$success = $tunnel->SshAuthenticatePw("mySshLogin","mySshPassword");
if ($success == 0) {
    print $tunnel->lastErrorText() . "\r\n";
    exit;
}

#  OK, the SSH tunnel is setup.  Now open a channel within the tunnel.
#  Once the channel is obtained, the Socket API may
#  be used exactly the same as usual, except all communications
#  are sent through the channel in the SSH tunnel.
#  Any number of channels may be created from the same SSH tunnel.
#  Multiple channels may coexist at the same time.

$imap = chilkat::CkImap->new();

#  Let the IMAP object also use the SSH tunnel
$success = $imap->UseSshTunnel($tunnel);
if ($success == 0) {
    print $imap->lastErrorText() . "\r\n";
    exit;
}

#  Connect to an IMAP server via the already established SSH tunnel.
#  Because the SSH tunnel has been previously setup,
#  this does not establish a direct connection with the IMAP
#  server.  It directs the SSH server to establish the connection.

#  In this example, the IMAP server requires SSL/TLS.  The TLS connection
#  will be enclosed within the SSH tunnel.
$imap->put_Ssl(1);
$imap->put_Port(993);
$success = $imap->Connect("imap.my-imap-server.com");
if ($success == 0) {
    print $imap->lastErrorText() . "\r\n";
    exit;
}

#  Authenticate with the IMAP server via the SSH tunnel.
$success = $imap->Login("myLogin","myPassword");
if ($success == 0) {
    print $imap->lastErrorText() . "\r\n";
    exit;
}

#  Select an IMAP mailbox
$success = $imap->SelectMailbox("Inbox");
if ($success == 0) {
    print $imap->lastErrorText() . "\r\n";
    exit;
}

#  How many messages in Inbox?
$msgCount = $imap->get_NumMessages();
if ($msgCount == 0) {
    print "No messages found." . "\r\n";
    exit;
}

$upperBound = 10;
if ($msgCount < $upperBound) {
    $upperBound = $msgCount;
}

#  Download up to the 1st 10 messages.
$email = chilkat::CkEmail->new();

$bUid = 0;
for ($i = 1; $i <= $upperBound; $i++) {

    $success = $imap->FetchEmail(0,$i,$bUid,$email);
    if ($success == 0) {
        print $imap->lastErrorText() . "\r\n";
        exit;
    }

    print $email->ck_from() . "\r\n";
    print $email->subject() . "\r\n";

}

#  Disconnect from the IMAP server.
#  The SSH tunnel remains open.
$success = $imap->Disconnect();
if ($success == 0) {
    print $imap->lastErrorText() . "\r\n";
    exit;
}

#  It is possible to re-use the existing SSH tunnel for the next connection:
$success = $imap->Connect("imap.my-imap-server2.com");
if ($success == 0) {
    print $imap->lastErrorText() . "\r\n";
    exit;
}

#  Review the LastErrorText to see that the connection was made via the SSH tunnel:
print $imap->lastErrorText() . "\r\n";

#  This closes the SSH channel, which is the connection with the IMAP server.
#  It does not close the SSH tunnel
$success = $imap->Disconnect();
if ($success == 0) {
    print $imap->lastErrorText() . "\r\n";
    exit;
}

#  Finally, close the SSH tunnel.

#  Note: If other objects are using the same SSH tunnel, the tunnel is not 
#  actually closed.  It is only closed when the last object using the tunnel closes it.

#  At this point, both the imap and tunnel objects have references to the internal
#  SSH tunnel.  We need to close each.

#  This call doesn't actually close the tunnel yet, because the tunnel object still
#  holds an internal reference.
$success = $imap->SshCloseTunnel();
if ($success == 0) {
    print $imap->lastErrorText() . "\r\n";
    exit;
}

#  This actually closes the SSH tunnel because it's the last object using it.
$success = $tunnel->SshCloseTunnel();
if ($success == 0) {
    print $tunnel->lastErrorText() . "\r\n";
    exit;
}

print "IMAP pre-existing SSH tunnel example completed." . "\r\n";