PHP Extension

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. PHP Extension

<?php

include("chilkat.php");

$success = false;

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

$tunnel = new CkSocket();

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

// Connect to an SSH server and establish the SSH tunnel:
$success = $tunnel->SshOpenTunnel($sshHostname,$sshPort);
if ($success == false) {
    print $tunnel->lastErrorText() . "\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 == false) {
    print $tunnel->lastErrorText() . "\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 = new CkImap();

// Let the IMAP object also use the SSH tunnel
$success = $imap->UseSshTunnel($tunnel);
if ($success == false) {
    print $imap->lastErrorText() . "\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(true);
$imap->put_Port(993);
$success = $imap->Connect('imap.my-imap-server.com');
if ($success == false) {
    print $imap->lastErrorText() . "\n";
    exit;
}

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

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

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

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

// Download up to the 1st 10 messages.
$email = new CkEmail();

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

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

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

}

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

// Review the LastErrorText to see that the connection was made via the SSH tunnel:
print $imap->lastErrorText() . "\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 == false) {
    print $imap->lastErrorText() . "\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 == false) {
    print $imap->lastErrorText() . "\n";
    exit;
}

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

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

?>