Awesome IMAP authentication backend for Dokuwiki

imap.class.php

<?php
/**
 * Awesome IMAP authentication backend
 *
 * Set in conf/dokuwiki.php:
 *
 *   $conf['authtype']    = 'imap';
 *   $conf['authdomain']  = 'example.com';                          // The default domain for IMAP-created users
 *   $conf['authserver']  = '{127.0.0.1:143/imap/novalidate-cert}'; // The IMAP server to which authenticate to
 *
 * As you can see, you don't need to create users beforehand.
 * They'll be created on the fly upon first successful login.
 *
 * @author  Marcello Barnaba <vjt@openssl.it>
 * @license Public Domain
 * @version 1.0
 * @date    February 2011
 */

define('DOKU_AUTH', dirname(__FILE__));
require_once(DOKU_AUTH.'/plain.class.php');
 
class auth_imap extends auth_plain
{
    function auth_imap()
    {
        // Requires the PHP IMAP module
        if (!extension_loaded('imap')) {
            msg('PHP IMAP module cannot be loaded', -1);
            $this->broken = true;
            return;
        }

        // Check configuration
        global $conf;
        if (!(isset($conf['authdomain']) && isset($conf['authserver']))) {
            msg('Please set $conf[\'authdomain\'] and $conf[\'authserver\']', -1);
            $this->broken = true;
            return;
        }

        $this->server = $conf['authserver'];
        $this->domain = $conf['authdomain'];

        // Call parent constructor
        parent::auth_plain();
 
        // Remove change password capability
        $this->cando['modPass'] = false;
    }
 
    /**
     * Checks the provided username and password using IMAP.
     * If the user doesn't exist, it is created on the fly.
     *
     * @param   string  $user   Username
     * @param   string  $pass   Password
     * @return  boolean True if authentication is successful
     */
    function checkPass($user, $pass)
    {
        if ($this->broken)
            return null;

        $handle = imap_open ($this->server, $user, $pass, OP_HALFOPEN|OP_READONLY);
        if (!$handle)
            return false; 

        imap_close ($handle);

        // If the user doesn't exist, create it
        //
        if (!$this->getUserData($user))
            return $this->createUser($user, 'antani', $user, $user.'@'.$this->domain);

        return true;
    }
}