auth/cas/auth.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Authentication Plugin: CAS Authentication
  19  *
  20  * Authentication using CAS (Central Authentication Server).
  21  *
  22  * @author Martin Dougiamas
  23  * @author Jerome GUTIERREZ
  24  * @author Iñaki Arenaza
  25  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
  26  * @package auth_cas
  27  */
  28
  29 defined('MOODLE_INTERNAL') || die();
  30
  31 require_once($CFG->dirroot.'/auth/ldap/auth.php');
  32 require_once($CFG->dirroot.'/auth/cas/CAS/CAS.php');
  33
  34 /**
  35  * CAS authentication plugin.
  36  */
  37 class auth_plugin_cas extends auth_plugin_ldap {
  38
  39     /**
  40      * Constructor.
  41      */
  42     public function __construct() {
  43         $this->authtype = 'cas';
  44         $this->roleauth = 'auth_cas';
  45         $this->errorlogtag = '[AUTH CAS] ';
  46         $this->init_plugin($this->authtype);
  47     }
  48
  49     /**
  50      * Old syntax of class constructor. Deprecated in PHP7.
  51      *
  52      * @deprecated since Moodle 3.1
  53      */
  54     public function auth_plugin_cas() {
  55         debugging('Use of class name as constructor is deprecated', DEBUG_DEVELOPER);
  56         self::__construct();
  57     }
  58
  59     function prevent_local_passwords() {
  60         return true;
  61     }
  62
  63     /**
  64      * Authenticates user against CAS
  65      * Returns true if the username and password work and false if they are
  66      * wrong or don't exist.
  67      *
  68      * @param string $username The username (with system magic quotes)
  69      * @param string $password The password (with system magic quotes)
  70      * @return bool Authentication success or failure.
  71      */
  72     function user_login ($username, $password) {
  73         $this->connectCAS();
  74         return phpCAS::isAuthenticated() && (trim(core_text::strtolower(phpCAS::getUser())) == $username);
  75     }
  76
  77     /**
  78      * Returns true if this authentication plugin is 'internal'.
  79      *
  80      * @return bool
  81      */
  82     function is_internal() {
  83         return false;
  84     }
  85
  86     /**
  87      * Returns true if this authentication plugin can change the user's
  88      * password.
  89      *
  90      * @return bool
  91      */
  92     function can_change_password() {
  93         return false;
  94     }
  95
  96     /**
  97      * Authentication choice (CAS or other)
  98      * Redirection to the CAS form or to login/index.php
  99      * for other authentication
 100      */
 101     function loginpage_hook() {
 102         global $frm;
 103         global $CFG;
 104         global $SESSION, $OUTPUT, $PAGE;
 105
 106         $site = get_site();
 107         $CASform = get_string('CASform', 'auth_cas');
 108         $username = optional_param('username', '', PARAM_RAW);
 109         $courseid = optional_param('courseid', 0, PARAM_INT);
 110
 111         if (!empty($username)) {
 112             if (isset($SESSION->wantsurl) && (strstr($SESSION->wantsurl, 'ticket') ||
 113                                               strstr($SESSION->wantsurl, 'NOCAS'))) {
 114                 unset($SESSION->wantsurl);
 115             }
 116             return;
 117         }
 118
 119         // Return if CAS enabled and settings not specified yet
 120         if (empty($this->config->hostname)) {
 121             return;
 122         }
 123
 124         // If the multi-authentication setting is used, check for the param before connecting to CAS.
 125         if ($this->config->multiauth) {
 126
 127             // If there is an authentication error, stay on the default authentication page.
 128             if (!empty($SESSION->loginerrormsg)) {
 129                 return;
 130             }
 131
 132             $authCAS = optional_param('authCAS', '', PARAM_RAW);
 133             if ($authCAS == 'NOCAS') {
 134                 return;
 135             }
 136             // Show authentication form for multi-authentication.
 137             // Test pgtIou parameter for proxy mode (https connection in background from CAS server to the php server).
 138             if ($authCAS != 'CAS' && !isset($_GET['pgtIou'])) {
 139                 $PAGE->set_url('/login/index.php');
 140                 $PAGE->navbar->add($CASform);
 141                 $PAGE->set_title("$site->fullname: $CASform");
 142                 $PAGE->set_heading($site->fullname);
 143                 echo $OUTPUT->header();
 144                 include($CFG->dirroot.'/auth/cas/cas_form.html');
 145                 echo $OUTPUT->footer();
 146                 exit();
 147             }
 148         }
 149
 150         // Connection to CAS server
 151         $this->connectCAS();
 152
 153         if (phpCAS::checkAuthentication()) {
 154             $frm = new stdClass();
 155             $frm->username = phpCAS::getUser();
 156             $frm->password = 'passwdCas';
 157
 158             // Redirect to a course if multi-auth is activated, authCAS is set to CAS and the courseid is specified.
 159             if ($this->config->multiauth && !empty($courseid)) {
 160                 redirect(new moodle_url('/course/view.php', array('id'=>$courseid)));
 161             }
 162
 163             return;
 164         }
 165
 166         if (isset($_GET['loginguest']) && ($_GET['loginguest'] == true)) {
 167             $frm = new stdClass();
 168             $frm->username = 'guest';
 169             $frm->password = 'guest';
 170             return;
 171         }
 172
 173         // Force CAS authentication (if needed).
 174         if (!phpCAS::isAuthenticated()) {
 175             phpCAS::setLang($this->config->language);
 176             phpCAS::forceAuthentication();
 177         }
 178     }
 179
 180
 181     /**
 182      * Connect to the CAS (clientcas connection or proxycas connection)
 183      *
 184      */
 185     function connectCAS() {
 186         global $CFG;
 187         static $connected = false;
 188
 189         if (!$connected) {
 190             // Make sure phpCAS doesn't try to start a new PHP session when connecting to the CAS server.
 191             if ($this->config->proxycas) {
 192                 phpCAS::proxy($this->config->casversion, $this->config->hostname, (int) $this->config->port, $this->config->baseuri, false);
 193             } else {
 194                 phpCAS::client($this->config->casversion, $this->config->hostname, (int) $this->config->port, $this->config->baseuri, false);
 195             }
 196             // Some CAS installs require SSLv3 that should be explicitly set.
 197             if (!empty($this->config->curl_ssl_version)) {
 198                 phpCAS::setExtraCurlOption(CURLOPT_SSLVERSION, $this->config->curl_ssl_version);
 199             }
 200
 201             $connected = true;
 202         }
 203
 204         // If Moodle is configured to use a proxy, phpCAS needs some curl options set.
 205         if (!empty($CFG->proxyhost) && !is_proxybypass(phpCAS::getServerLoginURL())) {
 206             phpCAS::setExtraCurlOption(CURLOPT_PROXY, $CFG->proxyhost);
 207             if (!empty($CFG->proxyport)) {
 208                 phpCAS::setExtraCurlOption(CURLOPT_PROXYPORT, $CFG->proxyport);
 209             }
 210             if (!empty($CFG->proxytype)) {
 211                 // Only set CURLOPT_PROXYTYPE if it's something other than the curl-default http
 212                 if ($CFG->proxytype == 'SOCKS5') {
 213                     phpCAS::setExtraCurlOption(CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
 214                 }
 215             }
 216             if (!empty($CFG->proxyuser) and !empty($CFG->proxypassword)) {
 217                 phpCAS::setExtraCurlOption(CURLOPT_PROXYUSERPWD, $CFG->proxyuser.':'.$CFG->proxypassword);
 218                 if (defined('CURLOPT_PROXYAUTH')) {
 219                     // any proxy authentication if PHP 5.1
 220                     phpCAS::setExtraCurlOption(CURLOPT_PROXYAUTH, CURLAUTH_BASIC | CURLAUTH_NTLM);
 221                 }
 222             }
 223         }
 224
 225         if ($this->config->certificate_check && $this->config->certificate_path){
 226             phpCAS::setCasServerCACert($this->config->certificate_path);
 227         } else {
 228             // Don't try to validate the server SSL credentials
 229             phpCAS::setNoCasServerValidation();
 230         }
 231     }
 232
 233     /**
 234      * Returns the URL for changing the user's pw, or empty if the default can
 235      * be used.
 236      *
 237      * @return moodle_url
 238      */
 239     function change_password_url() {
 240         return null;
 241     }
 242
 243     /**
 244      * Returns true if user should be coursecreator.
 245      *
 246      * @param mixed $username    username (without system magic quotes)
 247      * @return boolean result
 248      */
 249     function iscreator($username) {
 250         if (empty($this->config->host_url) or (empty($this->config->attrcreators) && empty($this->config->groupecreators)) or empty($this->config->memberattribute)) {
 251             return false;
 252         }
 253
 254         $extusername = core_text::convert($username, 'utf-8', $this->config->ldapencoding);
 255
 256         // Test for group creator
 257         if (!empty($this->config->groupecreators)) {
 258             $ldapconnection = $this->ldap_connect();
 259             if ($this->config->memberattribute_isdn) {
 260                 if(!($userid = $this->ldap_find_userdn($ldapconnection, $extusername))) {
 261                     return false;
 262                 }
 263             } else {
 264                 $userid = $extusername;
 265             }
 266
 267             $group_dns = explode(';', $this->config->groupecreators);
 268             if (ldap_isgroupmember($ldapconnection, $userid, $group_dns, $this->config->memberattribute)) {
 269                 return true;
 270             }
 271         }
 272
 273         // Build filter for attrcreator
 274         if (!empty($this->config->attrcreators)) {
 275             $attrs = explode(';', $this->config->attrcreators);
 276             $filter = '(& ('.$this->config->user_attribute."=$username)(|";
 277             foreach ($attrs as $attr){
 278                 if(strpos($attr, '=')) {
 279                     $filter .= "($attr)";
 280                 } else {
 281                     $filter .= '('.$this->config->memberattribute."=$attr)";
 282                 }
 283             }
 284             $filter .= '))';
 285
 286             // Search
 287             $result = $this->ldap_get_userlist($filter);
 288             if (count($result) != 0) {
 289                 return true;
 290             }
 291         }
 292
 293         return false;
 294     }
 295
 296     /**
 297      * Reads user information from LDAP and returns it as array()
 298      *
 299      * If no LDAP servers are configured, user information has to be
 300      * provided via other methods (CSV file, manually, etc.). Return
 301      * an empty array so existing user info is not lost. Otherwise,
 302      * calls parent class method to get user info.
 303      *
 304      * @param string $username username
 305      * @return mixed array with no magic quotes or false on error
 306      */
 307     function get_userinfo($username) {
 308         if (empty($this->config->host_url)) {
 309             return array();
 310         }
 311         return parent::get_userinfo($username);
 312     }
 313
 314     /**
 315      * Syncronizes users from LDAP server to moodle user table.
 316      *
 317      * If no LDAP servers are configured, simply return. Otherwise,
 318      * call parent class method to do the work.
 319      *
 320      * @param bool $do_updates will do pull in data updates from LDAP if relevant
 321      * @return nothing
 322      */
 323     function sync_users($do_updates=true) {
 324         if (empty($this->config->host_url)) {
 325             error_log('[AUTH CAS] '.get_string('noldapserver', 'auth_cas'));
 326             return;
 327         }
 328         parent::sync_users($do_updates);
 329     }
 330
 331     /**
 332     * Hook for logout page
 333     */
 334     function logoutpage_hook() {
 335         global $USER, $redirect;
 336
 337         // Only do this if the user is actually logged in via CAS
 338         if ($USER->auth === $this->authtype) {
 339             // Check if there is an alternative logout return url defined
 340             if (isset($this->config->logout_return_url) && !empty($this->config->logout_return_url)) {
 341                 // Set redirect to alternative return url
 342                 $redirect = $this->config->logout_return_url;
 343             }
 344         }
 345     }
 346
 347     /**
 348      * Post logout hook.
 349      *
 350      * Note: this method replace the prelogout_hook method to avoid redirect to CAS logout
 351      * before the event userlogout being triggered.
 352      *
 353      * @param stdClass $user clone of USER object object before the user session was terminated
 354      */
 355     public function postlogout_hook($user) {
 356         global $CFG;
 357         // Only redirect to CAS logout if the user is logged as a CAS user.
 358         if (!empty($this->config->logoutcas) && $user->auth == $this->authtype) {
 359             $backurl = !empty($this->config->logout_return_url) ? $this->config->logout_return_url : $CFG->wwwroot;
 360             $this->connectCAS();
 361             phpCAS::logoutWithRedirectService($backurl);
 362         }
 363     }
 364 }