IMAP Authentication for WordPress

<?php
/*
Plugin Name: IMAP Authentication
Version: 0.1
Plugin URI: http://blog.neverusethisfont.com/2008/08/imap-authentication-for-wordpress/
Description: Authenticate users using IMAP authentication.
Author: Aaron Parecki
Author URI: http://www.aaronparecki.com
 
Assumes a successful login against the IMAP server is a valid user, and auto-creates
the user in Wordpress if they don't already exist.
 
 
 
Copyright 2007 by Aaron Parecki  (email : aaron@parecki.com)
 
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
 
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
*/
 
add_action('admin_menu', array('IMAPAuthentication', 'admin_menu'));
add_action('lost_password', array('IMAPAuthentication', 'disable_password'));
add_action('retrieve_password', array('IMAPAuthentication', 'disable_password'));
add_action('password_reset', array('IMAPAuthentication', 'disable_password'));
add_filter('show_password_fields', array('IMAPAuthentication', 'show_password_fields'));
 
 
if( is_plugin_page() ) {
    $mailbox = IMAPAuthentication::get_mailbox();
    $user_suffix = IMAPAuthentication::get_user_suffix();
?>
<div class="wrap">
  <h2>IMAP Authentication Options</h2>
  <form name="imapauthenticationoptions" method="post" action="options.php">
    <?php wp_nonce_field('update-options'); ?>
    <input type="hidden" name="action" value="update" />
    <input type="hidden" name="page_options" value="imap_authentication_mailbox,imap_authentication_user_suffix" />
    <fieldset class="options">
      <table width="100%" cellspacing="2" cellpadding="5" class="form-table">
        <tr valign="top">
        <th width="33%" scope="row"><label for="imap_authentication_mailbox">Mailbox</label></th>
        <td><input name="imap_authentication_mailbox" type="text" id="imap_authentication_mailbox" value="<?php echo htmlspecialchars($mailbox) ?>" size="80" /><br />eg: {mail.example.com/readonly}INBOX or {mail.example.com:993/ssl/novalidate-cert/readonly}INBOX</td>
        </tr>
        <tr valign="top">
        <th scope="row"><label for="imap_authentication_user_suffix">User Suffix</label></th>
        <td><input name="imap_authentication_user_suffix" type="text" id="imap_authentication_user_suffix" value="<?php echo htmlspecialchars($user_suffix) ?>" size="50" /><br />A suffix to add to usernames (typically used to automatically add the domain part of the login).<br />eg: @example.com</td>
        </tr>
      </table>
    </fieldset>
    <p class="submit">
      <input type="submit" name="Submit" value="<?php _e('Save Changes') ?>" />
    </p>
  </form>
</div>
<?php
}
 
if( !class_exists('IMAPAuthentication') ) {
    class IMAPAuthentication {
        /*
         * Add an options pane for this plugin.
         */
        function admin_menu() {
            add_options_page('IMAP Authentication', 'IMAP Authentication', 10, __FILE__);
        }
 
        /*
         * Return the mailbox option from the database, creating the option if it doesn't exist.
         */
        function get_mailbox() {
            global $cache_nonexistantoptions;
 
            $mailbox = get_settings('imap_authentication_mailbox');
            if (! $mailbox or $cache_nonexistantoptions['imap_authentication_mailbox']) {
                $mailbox = '{localhost:143}INBOX';
                IMAPAuthentication::add_mailbox_option($mailbox);
            }
 
            return $mailbox;
        }
 
        /*
         * Add the mailbox option to the database.
         */
        function add_mailbox_option($mailbox) {
            add_option('imap_authentication_mailbox', $mailbox, 'The mailbox to try and log into.');
        }
 
        /*
         * Return the user_suffix option from the database, creating the option if it doesn't exist.
         */
        function get_user_suffix() {
            global $cache_nonexistantoptions;
 
            $user_suffix = get_settings('imap_authentication_user_suffix');
            if (! $user_suffix or $cache_nonexistantoptions['imap_authentication_user_suffix']) {
                $user_suffix = '';
                IMAPAuthentication::add_user_suffix_option($user_suffix);
            }
 
            return $user_suffix;
        }
 
        /*
         * Add the user_suffix option to the database.
         */
        function add_user_suffix_option($user_suffix) {
            add_option('imap_authentication_user_suffix', $user_suffix, 'A suffix to add to usernames (typically used to automatically add the domain part of the login).');
        }
 
        // custom error handler
        function eh($type, $msg, $file, $line, $context)
        {
            $error = $error.$msg;
        }
 
        function login($username, $password) {
        	global $wpdb;
 
			$mbox = imap_open(IMAPAuthentication::get_mailbox(), $username.IMAPAuthentication::get_user_suffix(), $password, OP_HALFOPEN) or $error = imap_last_error();
 
			if ($mbox) {
				$user = get_userdatabylogin($username);
 
				if( $user === false ) {
					// the user checked out on the IMAP server, but there was no record in the database. Automatically add it now.
					$wpdb->query( $wpdb->prepare("INSERT INTO $wpdb->users (user_login, user_nicename, user_email, display_name) VALUES(%s, %s, %s, %s)", $username, $username, $username.IMAPAuthentication::get_user_suffix(), $username) );
					$user = get_userdatabylogin($username);
 
					$wpdb->query( $wpdb->prepare("INSERT INTO $wpdb->usermeta (user_id, meta_key, meta_value) VALUES(%d, %s, %s)", $user->ID, 'nickname', $username) );
					$wpdb->query( $wpdb->prepare("INSERT INTO $wpdb->usermeta (user_id, meta_key, meta_value) VALUES(%d, %s, %s)", $user->ID, 'rich_editing', 'true') );
					$wpdb->query( $wpdb->prepare("INSERT INTO $wpdb->usermeta (user_id, meta_key, meta_value) VALUES(%d, %s, %s)", $user->ID, 'wp_capabilities', 'a:1:{s:6:"author";b:1;}') );
					$wpdb->query( $wpdb->prepare("INSERT INTO $wpdb->usermeta (user_id, meta_key, meta_value) VALUES(%d, %s, %s)", $user->ID, 'wp_user_level', '2') );
 
				}
 
				imap_close($mbox);
				return new WP_User($user->ID);
			} else {
				do_action( 'wp_login_failed', $username );
				return new WP_Error('incorrect_password', __('<strong>ERROR</strong>: Incorrect password.'));
			}
        }
 
        /*
         * Used to disable certain login functions, e.g. retrieving a
         * user's password.
         */
        function disable_password() {
            login_header('Login', '<p class="message"><strong>ERROR</strong>: You can\'t do that here. This blog uses the IMAP login mechanism. Your password is set with your email account.</p>', 'error');
			die();
        }
 
        /*
         * Used to disable certain display elements, e.g. password
         * fields on profile screen.
         */
        function show_password_fields($username) {
            return false;
        }
    }
}
 
 
if( !is_plugin_page() ) :
 
function wp_authenticate($username, $password) {
	return IMAPAuthentication::login($username, $password);
}
endif;
 
 
?>