source: extensions/Ldap_Login/main.inc.php

<?php
/*
Plugin Name: Ldap_Login
Version: 1.2
Description: Allow piwigo authentication along an ldap
Plugin URI: http://www.22decembre.eu/2014/02/09/piwigo-ldap-login-v1-1/
Author: 22decembre
Author URI: http://www.22decembre.eu
*/
if (!defined('PHPWG_ROOT_PATH')) die('Hacking attempt!');

// +-----------------------------------------------------------------------+
// | Define plugin constants                                               |
// +-----------------------------------------------------------------------+
define('LDAP_LOGIN_ID',      basename(dirname(__FILE__)));
define('LDAP_LOGIN_PATH' ,   __DIR__ . '/');
define('LDAP_LOGIN_ADMIN',   get_root_url() . 'admin.php?page=plugin-' . LDAP_LOGIN_ID);
define('LDAP_LOGIN_VERSION', '1.2');

include_once(LDAP_LOGIN_PATH.'/class.ldap.php');

// +-----------------------------------------------------------------------+
// | Event handlers                                                        |
// +-----------------------------------------------------------------------+

add_event_handler('init', 'ld_init');

add_event_handler('try_log_user','login', 0, 4);

add_event_handler('get_admin_plugin_menu_links', array(&$ldap, 'ldap_admin_menu'));

// +-----------------------------------------------------------------------+
// | Admin menu loading                                                    |
// +-----------------------------------------------------------------------+

$ldap = new Ldap();
$ldap->load_config();
set_plugin_data($plugin['id'], $ldap);
unset($ldap);

// +-----------------------------------------------------------------------+
// | functions                                                             |
// +-----------------------------------------------------------------------+

function random_password( $length = 8 ) {
    $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()_-=+;:,.?";
    $password = substr( str_shuffle( $chars ), 0, $length );
    return $password;
}

function ld_init(){
        load_language('plugin.lang', LDAP_LOGIN_PATH);
        global $conf;
}

function fail($username) {
        trigger_action('login_failure', stripslashes($username));
        return false;
}

function update_user($username,$id) {
        $up = new Ldap();
        $up->load_config();
        $up->ldap_conn() or error_log("Unable to connect LDAP server : ".$up->getErrorString());

        // update user piwigo rights / access according to ldap. Only if it's webmaster / admin, so no normal !
        if($up->ldap_status($username) !='normal') {
                single_update(USER_INFOS_TABLE,array('status' => $up->ldap_status($username)),array('user_id' => $id));
        }

        // search groups
        $group_query = 'SELECT name, id FROM '.GROUPS_TABLE.';';
        
        $result = pwg_query($group_query);
        $inserts = array();
        while ($row = pwg_db_fetch_assoc($result))
        {
                if($up->user_membership($username, $up->ldap_group($row['name']))) {
                        $inserts[] = array('user_id' => $id,'group_id' => $row['id']);
                }
        }

        if (count($inserts) > 0)
        {
                mass_inserts(USER_GROUP_TABLE, array('user_id', 'group_id'), $inserts,array('ignore'=>true));
        }
}

function login($success, $username, $password, $remember_me){

        global $conf;
        $allow_auth = False;
        
        $obj = new Ldap();
        $obj->load_config();
        $obj->ldap_conn() or error_log("Unable to connect LDAP server : ".$obj->getErrorString());
        
        // if there's a users group...
        if ($obj->config['users_group']) {
                // and the user is in
                if ($obj->user_membership($username,$obj->ldap_group($obj->config['users_group']))) {
                        // it can continue
                        $allow_auth = True;
                }
                else
                {       // otherwise it means the user is not allowed to enter !
                        fail($username);
                }
        }
        else {
        // if there's no user group, we can continue.
        $allow_auth = True;
        }
        
        if ($allow_auth) {
                if ($obj->ldap_bind_as($username,$password)){ // bind with userdn
                        // search user in piwigo database
                        $query = '
                                SELECT  '.$conf['user_fields']['id'].' AS id
                                FROM '.USERS_TABLE.'
                                WHERE   '.$conf['user_fields']['username'].' = \''.pwg_db_real_escape_string($username).'\';';
                        $row = pwg_db_fetch_assoc(pwg_query($query));

                        // if query is not empty, it means everything is ok and we can continue, auth is done !
                        if (!empty($row['id'])) {
                                update_user($username,$row['id']);
                                
                                log_user($row['id'], $remember_me);
                                trigger_action('login_success', stripslashes($username));
                                
                                return True;
                        }
        
                        // if query is empty but ldap auth is done we can create a piwigo user if it's said so !
                        else {
                                // this is where we check we are allowed to create new users upon that.
                                if ($obj->config['allow_newusers']) {
                        
                                        // we got the email address
                                        if ($obj->ldap_mail($username)) {
                                                $mail = $obj->ldap_mail($username);
                                        }
                                        else {
                                                $mail = NULL;
                                        }
                        
                                        // we actually register the new user
                                        $new_id = register_user($username,random_password(8),$mail);
                                        update_user($username,$new_id);
                        
                                        // now we fetch again his id in the piwigo db, and we get them, as we just created him !
                                        log_user($new_id, False);
                                        
                                        trigger_action('login_success', stripslashes($username));
                                        
                                        redirect('profile.php');
                                        return true;
                                }
                                // else : this is the normal behavior ! user is not created.
                                else { fail($username); }
                        }
                }
                // ldap_bind_as was not successful
                else { fail($username); }
        }
        // user is not allowed to auth or auth is wrong !
        else { fail($username); }
}
?>