auth.php

<?php

/*
  Copyright 2012 Marvin Pinto (me@marvinp.ca)

  Licensed under the Apache License, Version 2.0 (the "License"); you may not
  use this file except in compliance with the License.  You may obtain a copy of
  the License at

  http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
  License for the specific language governing permissions and limitations under
  the License.
*/

if (!defined('MOODLE_INTERNAL')) {
  die('Direct access to this script is forbidden.');    // It must be included
                                                        // from a Moodle page
}

require_once($CFG->libdir.'/authlib.php');
require_once(dirname(__FILE__).'/lib.php');

/**
 * Plugin for ssso authentication.
 */
class auth_plugin_ssso extends auth_plugin_base {


  // Constructor
  function auth_plugin_ssso() {
    $this->authtype = 'ssso';
    $this->config = get_config('auth/ssso');
  }


  // We don't acutally authenticate anyone, we're just here for the hooks
  function user_login ($username, $password) {
    return false;
  }


  // Create a new SSO compatible cookie for this user.
  function user_authenticated_hook(&$user, $username, $password) {
    $this->ssso_set_sso_cookie($username);
  }


  // Clear the SSO cookie when the user logs out.
  function prelogout_hook() {
    $this->ssso_set_sso_cookie('');
  }


  // Defaults for configuration values.
  function get_defaults() {
    return array (
                  'ssso_cookiename' => get_string('ssso_cookiename_default', 'auth_ssso'),
                  'ssso_cookiepath' => get_string('ssso_cookiepath_default', 'auth_ssso'),
                  'ssso_cookiedomain' => get_string('ssso_cookiedomain_default', 'auth_ssso'),
                  'ssso_cookieexpiry' => get_string('ssso_cookieexpiry_default', 'auth_ssso'),
                  'ssso_cookiesecret' => get_string('ssso_cookiesecret_default', 'auth_ssso'),
                  'ssso_cookiesalt' => get_string('ssso_cookiesalt_default', 'auth_ssso')
                  );
  }


  function config_form($config, $err, $user_fields) {
    foreach ($this->get_defaults() as $key => $value) {
      if (isset($config->$key)) continue;
      $config->$key = $value;
    }
    include dirname(__FILE__).'/config.php';
  }


  function process_config($config) {
    global $CFG;
    $defaults = $this->get_defaults();
    foreach ($defaults as $key => $value) {
      if (isset($config->$key)) continue;
      $config->$key = $value;
    }

    foreach (array_keys($defaults) as $key) {
      set_config($key, $config->$key, 'auth/ssso');
    }
    return true;
  }


  /**
   * Set/delete an SSO compatible cookie
   *
   * @param string $username to encrypt and place in a cookie, '' means delete
   *    current cookie
   * @return void
   */
  function ssso_set_sso_cookie($username='') {
    global $DB;

    $cookiename = $this->config->ssso_cookiename;
    $cookiepath = $this->config->ssso_cookiepath;
    $cookiedomain = $this->config->ssso_cookiedomain;
    $cookieexpiry = $this->config->ssso_cookieexpiry;
    $cookiekey = $this->config->ssso_cookiesecret;
    $cookiesalt = $this->config->ssso_cookiesalt;

    // delete old cookie
    setcookie($cookiename, '', time()-HOURSECS, $cookiepath, $cookiedomain);

    // Issue a new SSO cookie
    if ($username != '') {
      $m_user = $DB->get_record('user', array('username'=>$username));
      $m_email = $m_user->email;
      if (! $m_email) {
        $m_email = '';
      }

      $ck_ip = $_SERVER["REMOTE_ADDR"];
      $ck_username = $username;
      $ck_expiry = time()+(HOURSECS*$cookieexpiry);
      $cookievalue = ssso_get_cookie_data($cookiekey, $cookiesalt, $ck_username,
                                          $ck_ip, $ck_expiry, $m_email);
      setcookie($cookiename, $cookievalue, $ck_expiry,
                $cookiepath, $cookiedomain);
    }
  }


}