auth/db/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: External Database Authentication
  19  *
  20  * Checks against an external database.
  21  *
  22  * @package    auth_db
  23  * @author     Martin Dougiamas
  24  * @license    http://www.gnu.org/copyleft/gpl.html GNU Public License
  25  */
  26
  27 defined('MOODLE_INTERNAL') || die();
  28
  29 require_once($CFG->libdir.'/authlib.php');
  30
  31 /**
  32  * External database authentication plugin.
  33  */
  34 class auth_plugin_db extends auth_plugin_base {
  35
  36     /**
  37      * Constructor.
  38      */
  39     function __construct() {
  40         global $CFG;
  41         require_once($CFG->libdir.'/adodb/adodb.inc.php');
  42
  43         $this->authtype = 'db';
  44         $this->config = get_config('auth/db');
  45         if (empty($this->config->extencoding)) {
  46             $this->config->extencoding = 'utf-8';
  47         }
  48     }
  49
  50     /**
  51      * Returns true if the username and password work and false if they are
  52      * wrong or don't exist.
  53      *
  54      * @param string $username The username
  55      * @param string $password The password
  56      * @return bool Authentication success or failure.
  57      */
  58     function user_login($username, $password) {
  59         global $CFG, $DB;
  60
  61         $extusername = core_text::convert($username, 'utf-8', $this->config->extencoding);
  62         $extpassword = core_text::convert($password, 'utf-8', $this->config->extencoding);
  63
  64         if ($this->is_internal()) {
  65             // Lookup username externally, but resolve
  66             // password locally -- to support backend that
  67             // don't track passwords.
  68
  69             if (isset($this->config->removeuser) and $this->config->removeuser == AUTH_REMOVEUSER_KEEP) {
  70                 // No need to connect to external database in this case because users are never removed and we verify password locally.
  71                 if ($user = $DB->get_record('user', array('username'=>$username, 'mnethostid'=>$CFG->mnet_localhost_id, 'auth'=>$this->authtype))) {
  72                     return validate_internal_user_password($user, $password);
  73                 } else {
  74                     return false;
  75                 }
  76             }
  77
  78             $authdb = $this->db_init();
  79
  80             $rs = $authdb->Execute("SELECT *
  81                                       FROM {$this->config->table}
  82                                      WHERE {$this->config->fielduser} = '".$this->ext_addslashes($extusername)."'");
  83             if (!$rs) {
  84                 $authdb->Close();
  85                 debugging(get_string('auth_dbcantconnect','auth_db'));
  86                 return false;
  87             }
  88
  89             if (!$rs->EOF) {
  90                 $rs->Close();
  91                 $authdb->Close();
  92                 // User exists externally - check username/password internally.
  93                 if ($user = $DB->get_record('user', array('username'=>$username, 'mnethostid'=>$CFG->mnet_localhost_id, 'auth'=>$this->authtype))) {
  94                     return validate_internal_user_password($user, $password);
  95                 }
  96             } else {
  97                 $rs->Close();
  98                 $authdb->Close();
  99                 // User does not exist externally.
 100                 return false;
 101             }
 102
 103         } else {
 104             // Normal case: use external db for both usernames and passwords.
 105
 106             $authdb = $this->db_init();
 107
 108             if ($this->config->passtype === 'md5') {   // Re-format password accordingly.
 109                 $extpassword = md5($extpassword);
 110             } else if ($this->config->passtype === 'sha1') {
 111                 $extpassword = sha1($extpassword);
 112             }
 113
 114             $rs = $authdb->Execute("SELECT *
 115                                       FROM {$this->config->table}
 116                                      WHERE {$this->config->fielduser} = '".$this->ext_addslashes($extusername)."'
 117                                            AND {$this->config->fieldpass} = '".$this->ext_addslashes($extpassword)."'");
 118             if (!$rs) {
 119                 $authdb->Close();
 120                 debugging(get_string('auth_dbcantconnect','auth_db'));
 121                 return false;
 122             }
 123
 124             if (!$rs->EOF) {
 125                 $rs->Close();
 126                 $authdb->Close();
 127                 return true;
 128             } else {
 129                 $rs->Close();
 130                 $authdb->Close();
 131                 return false;
 132             }
 133
 134         }
 135     }
 136
 137     /**
 138      * Connect to external database.
 139      *
 140      * @return ADOConnection
 141      */
 142     function db_init() {
 143         // Connect to the external database (forcing new connection).
 144         $authdb = ADONewConnection($this->config->type);
 145         if (!empty($this->config->debugauthdb)) {
 146             $authdb->debug = true;
 147             ob_start(); //Start output buffer to allow later use of the page headers.
 148         }
 149         $authdb->Connect($this->config->host, $this->config->user, $this->config->pass, $this->config->name, true);
 150         $authdb->SetFetchMode(ADODB_FETCH_ASSOC);
 151         if (!empty($this->config->setupsql)) {
 152             $authdb->Execute($this->config->setupsql);
 153         }
 154
 155         return $authdb;
 156     }
 157
 158     /**
 159      * Returns user attribute mappings between moodle and ldap.
 160      *
 161      * @return array
 162      */
 163     function db_attributes() {
 164         $moodleattributes = array();
 165         foreach ($this->userfields as $field) {
 166             if (!empty($this->config->{"field_map_$field"})) {
 167                 $moodleattributes[$field] = $this->config->{"field_map_$field"};
 168             }
 169         }
 170         $moodleattributes['username'] = $this->config->fielduser;
 171         return $moodleattributes;
 172     }
 173
 174     /**
 175      * Reads any other information for a user from external database,
 176      * then returns it in an array.
 177      *
 178      * @param string $username
 179      * @return array
 180      */
 181     function get_userinfo($username) {
 182         global $CFG;
 183
 184         $extusername = core_text::convert($username, 'utf-8', $this->config->extencoding);
 185
 186         $authdb = $this->db_init();
 187
 188         // Array to map local fieldnames we want, to external fieldnames.
 189         $selectfields = $this->db_attributes();
 190
 191         $result = array();
 192         // If at least one field is mapped from external db, get that mapped data.
 193         if ($selectfields) {
 194             $select = array();
 195             foreach ($selectfields as $localname=>$externalname) {
 196                 $select[] = "$externalname AS $localname";
 197             }
 198             $select = implode(', ', $select);
 199             $sql = "SELECT $select
 200                       FROM {$this->config->table}
 201                      WHERE {$this->config->fielduser} = '".$this->ext_addslashes($extusername)."'";
 202             if ($rs = $authdb->Execute($sql)) {
 203                 if (!$rs->EOF) {
 204                     $fields_obj = $rs->FetchObj();
 205                     $fields_obj = (object)array_change_key_case((array)$fields_obj , CASE_LOWER);
 206                     foreach ($selectfields as $localname=>$externalname) {
 207                         $result[$localname] = core_text::convert($fields_obj->{$localname}, $this->config->extencoding, 'utf-8');
 208                      }
 209                  }
 210                  $rs->Close();
 211             }
 212         }
 213         $authdb->Close();
 214         return $result;
 215     }
 216
 217     /**
 218      * Change a user's password.
 219      *
 220      * @param  stdClass  $user      User table object
 221      * @param  string  $newpassword Plaintext password
 222      * @return bool                 True on success
 223      */
 224     function user_update_password($user, $newpassword) {
 225         global $DB;
 226
 227         if ($this->is_internal()) {
 228             $puser = $DB->get_record('user', array('id'=>$user->id), '*', MUST_EXIST);
 229             // This will also update the stored hash to the latest algorithm
 230             // if the existing hash is using an out-of-date algorithm (or the
 231             // legacy md5 algorithm).
 232             if (update_internal_user_password($puser, $newpassword)) {
 233                 $user->password = $puser->password;
 234                 return true;
 235             } else {
 236                 return false;
 237             }
 238         } else {
 239             // We should have never been called!
 240             return false;
 241         }
 242     }
 243
 244     /**
 245      * Synchronizes user from external db to moodle user table.
 246      *
 247      * Sync should be done by using idnumber attribute, not username.
 248      * You need to pass firstsync parameter to function to fill in
 249      * idnumbers if they don't exists in moodle user table.
 250      *
 251      * Syncing users removes (disables) users that don't exists anymore in external db.
 252      * Creates new users and updates coursecreator status of users.
 253      *
 254      * This implementation is simpler but less scalable than the one found in the LDAP module.
 255      *
 256      * @param progress_trace $trace
 257      * @param bool $do_updates  Optional: set to true to force an update of existing accounts
 258      * @return int 0 means success, 1 means failure
 259      */
 260     function sync_users(progress_trace $trace, $do_updates=false) {
 261         global $CFG, $DB;
 262
 263         require_once($CFG->dirroot . '/user/lib.php');
 264
 265         // List external users.
 266         $userlist = $this->get_userlist();
 267
 268         // Delete obsolete internal users.
 269         if (!empty($this->config->removeuser)) {
 270
 271             $suspendselect = "";
 272             if ($this->config->removeuser == AUTH_REMOVEUSER_SUSPEND) {
 273                 $suspendselect = "AND u.suspended = 0";
 274             }
 275
 276             // Find obsolete users.
 277             if (count($userlist)) {
 278                 list($notin_sql, $params) = $DB->get_in_or_equal($userlist, SQL_PARAMS_NAMED, 'u', false);
 279                 $params['authtype'] = $this->authtype;
 280                 $sql = "SELECT u.*
 281                           FROM {user} u
 282                          WHERE u.auth=:authtype AND u.deleted=0 AND u.mnethostid=:mnethostid $suspendselect AND u.username $notin_sql";
 283             } else {
 284                 $sql = "SELECT u.*
 285                           FROM {user} u
 286                          WHERE u.auth=:authtype AND u.deleted=0 AND u.mnethostid=:mnethostid $suspendselect";
 287                 $params = array();
 288                 $params['authtype'] = $this->authtype;
 289             }
 290             $params['mnethostid'] = $CFG->mnet_localhost_id;
 291             $remove_users = $DB->get_records_sql($sql, $params);
 292
 293             if (!empty($remove_users)) {
 294                 $trace->output(get_string('auth_dbuserstoremove','auth_db', count($remove_users)));
 295
 296                 foreach ($remove_users as $user) {
 297                     if ($this->config->removeuser == AUTH_REMOVEUSER_FULLDELETE) {
 298                         delete_user($user);
 299                         $trace->output(get_string('auth_dbdeleteuser', 'auth_db', array('name'=>$user->username, 'id'=>$user->id)), 1);
 300                     } else if ($this->config->removeuser == AUTH_REMOVEUSER_SUSPEND) {
 301                         $updateuser = new stdClass();
 302                         $updateuser->id   = $user->id;
 303                         $updateuser->suspended = 1;
 304                         user_update_user($updateuser, false);
 305                         $trace->output(get_string('auth_dbsuspenduser', 'auth_db', array('name'=>$user->username, 'id'=>$user->id)), 1);
 306                     }
 307                 }
 308             }
 309             unset($remove_users);
 310         }
 311
 312         if (!count($userlist)) {
 313             // Exit right here, nothing else to do.
 314             $trace->finished();
 315             return 0;
 316         }
 317
 318         // Update existing accounts.
 319         if ($do_updates) {
 320             // Narrow down what fields we need to update.
 321             $all_keys = array_keys(get_object_vars($this->config));
 322             $updatekeys = array();
 323             foreach ($all_keys as $key) {
 324                 if (preg_match('/^field_updatelocal_(.+)$/',$key, $match)) {
 325                     if ($this->config->{$key} === 'onlogin') {
 326                         array_push($updatekeys, $match[1]); // The actual key name.
 327                     }
 328                 }
 329             }
 330             unset($all_keys); unset($key);
 331
 332             // Only go ahead if we actually have fields to update locally.
 333             if (!empty($updatekeys)) {
 334                 list($in_sql, $params) = $DB->get_in_or_equal($userlist, SQL_PARAMS_NAMED, 'u', true);
 335                 $params['authtype'] = $this->authtype;
 336                 $sql = "SELECT u.id, u.username
 337                           FROM {user} u
 338                          WHERE u.auth=:authtype AND u.deleted=0 AND u.username {$in_sql}";
 339                 if ($update_users = $DB->get_records_sql($sql, $params)) {
 340                     $trace->output("User entries to update: ".count($update_users));
 341
 342                     foreach ($update_users as $user) {
 343                         if ($this->update_user_record($user->username, $updatekeys)) {
 344                             $trace->output(get_string('auth_dbupdatinguser', 'auth_db', array('name'=>$user->username, 'id'=>$user->id)), 1);
 345                         } else {
 346                             $trace->output(get_string('auth_dbupdatinguser', 'auth_db', array('name'=>$user->username, 'id'=>$user->id))." - ".get_string('skipped'), 1);
 347                         }
 348                     }
 349                     unset($update_users);
 350                 }
 351             }
 352         }
 353
 354
 355         // Create missing accounts.
 356         // NOTE: this is very memory intensive and generally inefficient.
 357         $suspendselect = "";
 358         if ($this->config->removeuser == AUTH_REMOVEUSER_SUSPEND) {
 359             $suspendselect = "AND u.suspended = 0";
 360         }
 361         $sql = "SELECT u.id, u.username
 362                   FROM {user} u
 363                  WHERE u.auth=:authtype AND u.deleted='0' AND mnethostid=:mnethostid $suspendselect";
 364
 365         $users = $DB->get_records_sql($sql, array('authtype'=>$this->authtype, 'mnethostid'=>$CFG->mnet_localhost_id));
 366
 367         // Simplify down to usernames.
 368         $usernames = array();
 369         if (!empty($users)) {
 370             foreach ($users as $user) {
 371                 array_push($usernames, $user->username);
 372             }
 373             unset($users);
 374         }
 375
 376         $add_users = array_diff($userlist, $usernames);
 377         unset($usernames);
 378
 379         if (!empty($add_users)) {
 380             $trace->output(get_string('auth_dbuserstoadd','auth_db',count($add_users)));
 381             // Do not use transactions around this foreach, we want to skip problematic users, not revert everything.
 382             foreach($add_users as $user) {
 383                 $username = $user;
 384                 if ($this->config->removeuser == AUTH_REMOVEUSER_SUSPEND) {
 385                     if ($olduser = $DB->get_record('user', array('username' => $username, 'deleted' => 0, 'suspended' => 1,
 386                             'mnethostid' => $CFG->mnet_localhost_id, 'auth' => $this->authtype))) {
 387                         $updateuser = new stdClass();
 388                         $updateuser->id = $olduser->id;
 389                         $updateuser->suspended = 0;
 390                         user_update_user($updateuser);
 391                         $trace->output(get_string('auth_dbreviveduser', 'auth_db', array('name' => $username,
 392                             'id' => $olduser->id)), 1);
 393                         continue;
 394                     }
 395                 }
 396
 397                 // Do not try to undelete users here, instead select suspending if you ever expect users will reappear.
 398
 399                 // Prep a few params.
 400                 $user = $this->get_userinfo_asobj($user);
 401                 $user->username   = $username;
 402                 $user->confirmed  = 1;
 403                 $user->auth       = $this->authtype;
 404                 $user->mnethostid = $CFG->mnet_localhost_id;
 405                 if (empty($user->lang)) {
 406                     $user->lang = $CFG->lang;
 407                 }
 408                 if ($collision = $DB->get_record_select('user', "username = :username AND mnethostid = :mnethostid AND auth <> :auth", array('username'=>$user->username, 'mnethostid'=>$CFG->mnet_localhost_id, 'auth'=>$this->authtype), 'id,username,auth')) {
 409                     $trace->output(get_string('auth_dbinsertuserduplicate', 'auth_db', array('username'=>$user->username, 'auth'=>$collision->auth)), 1);
 410                     continue;
 411                 }
 412                 try {
 413                     $id = user_create_user($user, false); // It is truly a new user.
 414                     $trace->output(get_string('auth_dbinsertuser', 'auth_db', array('name'=>$user->username, 'id'=>$id)), 1);
 415                 } catch (moodle_exception $e) {
 416                     $trace->output(get_string('auth_dbinsertusererror', 'auth_db', $user->username), 1);
 417                     continue;
 418                 }
 419                 // If relevant, tag for password generation.
 420                 if ($this->is_internal()) {
 421                     set_user_preference('auth_forcepasswordchange', 1, $id);
 422                     set_user_preference('create_password',          1, $id);
 423                 }
 424                 // Make sure user context is present.
 425                 context_user::instance($id);
 426             }
 427             unset($add_users);
 428         }
 429         $trace->finished();
 430         return 0;
 431     }
 432
 433     function user_exists($username) {
 434
 435         // Init result value.
 436         $result = false;
 437
 438         $extusername = core_text::convert($username, 'utf-8', $this->config->extencoding);
 439
 440         $authdb = $this->db_init();
 441
 442         $rs = $authdb->Execute("SELECT *
 443                                   FROM {$this->config->table}
 444                                  WHERE {$this->config->fielduser} = '".$this->ext_addslashes($extusername)."' ");
 445
 446         if (!$rs) {
 447             print_error('auth_dbcantconnect','auth_db');
 448         } else if (!$rs->EOF) {
 449             // User exists externally.
 450             $result = true;
 451         }
 452
 453         $authdb->Close();
 454         return $result;
 455     }
 456
 457
 458     function get_userlist() {
 459
 460         // Init result value.
 461         $result = array();
 462
 463         $authdb = $this->db_init();
 464
 465         // Fetch userlist.
 466         $rs = $authdb->Execute("SELECT {$this->config->fielduser} AS username
 467                                   FROM {$this->config->table} ");
 468
 469         if (!$rs) {
 470             print_error('auth_dbcantconnect','auth_db');
 471         } else if (!$rs->EOF) {
 472             while ($rec = $rs->FetchRow()) {
 473                 $rec = (object)array_change_key_case((array)$rec , CASE_LOWER);
 474                 array_push($result, $rec->username);
 475             }
 476         }
 477
 478         $authdb->Close();
 479         return $result;
 480     }
 481
 482     /**
 483      * Reads user information from DB and return it in an object.
 484      *
 485      * @param string $username username
 486      * @return array
 487      */
 488     function get_userinfo_asobj($username) {
 489         $user_array = truncate_userinfo($this->get_userinfo($username));
 490         $user = new stdClass();
 491         foreach($user_array as $key=>$value) {
 492             $user->{$key} = $value;
 493         }
 494         return $user;
 495     }
 496
 497     /**
 498      * will update a local user record from an external source.
 499      * is a lighter version of the one in moodlelib -- won't do
 500      * expensive ops such as enrolment.
 501      *
 502      * If you don't pass $updatekeys, there is a performance hit and
 503      * values removed from DB won't be removed from moodle.
 504      *
 505      * @param string $username username
 506      * @param bool $updatekeys
 507      * @return stdClass
 508      */
 509     function update_user_record($username, $updatekeys=false) {
 510         global $CFG, $DB;
 511
 512         //just in case check text case
 513         $username = trim(core_text::strtolower($username));
 514
 515         // get the current user record
 516         $user = $DB->get_record('user', array('username'=>$username, 'mnethostid'=>$CFG->mnet_localhost_id));
 517         if (empty($user)) { // trouble
 518             error_log("Cannot update non-existent user: $username");
 519             print_error('auth_dbusernotexist','auth_db',$username);
 520             die;
 521         }
 522
 523         // Ensure userid is not overwritten.
 524         $userid = $user->id;
 525         $needsupdate = false;
 526
 527         $updateuser = new stdClass();
 528         $updateuser->id = $userid;
 529         if ($newinfo = $this->get_userinfo($username)) {
 530             $newinfo = truncate_userinfo($newinfo);
 531
 532             if (empty($updatekeys)) { // All keys? This does not support removing values.
 533                 $updatekeys = array_keys($newinfo);
 534             }
 535
 536             foreach ($updatekeys as $key) {
 537                 if (isset($newinfo[$key])) {
 538                     $value = $newinfo[$key];
 539                 } else {
 540                     $value = '';
 541                 }
 542
 543                 if (!empty($this->config->{'field_updatelocal_' . $key})) {
 544                     if (isset($user->{$key}) and $user->{$key} != $value) { // Only update if it's changed.
 545                         $needsupdate = true;
 546                         $updateuser->$key = $value;
 547                     }
 548                 }
 549             }
 550         }
 551         if ($needsupdate) {
 552             require_once($CFG->dirroot . '/user/lib.php');
 553             user_update_user($updateuser);
 554         }
 555         return $DB->get_record('user', array('id'=>$userid, 'deleted'=>0));
 556     }
 557
 558     /**
 559      * Called when the user record is updated.
 560      * Modifies user in external database. It takes olduser (before changes) and newuser (after changes)
 561      * compares information saved modified information to external db.
 562      *
 563      * @param stdClass $olduser     Userobject before modifications
 564      * @param stdClass $newuser     Userobject new modified userobject
 565      * @return boolean result
 566      *
 567      */
 568     function user_update($olduser, $newuser) {
 569         if (isset($olduser->username) and isset($newuser->username) and $olduser->username != $newuser->username) {
 570             error_log("ERROR:User renaming not allowed in ext db");
 571             return false;
 572         }
 573
 574         if (isset($olduser->auth) and $olduser->auth != $this->authtype) {
 575             return true; // Just change auth and skip update.
 576         }
 577
 578         $curruser = $this->get_userinfo($olduser->username);
 579         if (empty($curruser)) {
 580             error_log("ERROR:User $olduser->username found in ext db");
 581             return false;
 582         }
 583
 584         $extusername = core_text::convert($olduser->username, 'utf-8', $this->config->extencoding);
 585
 586         $authdb = $this->db_init();
 587
 588         $update = array();
 589         foreach($curruser as $key=>$value) {
 590             if ($key == 'username') {
 591                 continue; // Skip this.
 592             }
 593             if (empty($this->config->{"field_updateremote_$key"})) {
 594                 continue; // Remote update not requested.
 595             }
 596             if (!isset($newuser->$key)) {
 597                 continue;
 598             }
 599             $nuvalue = $newuser->$key;
 600             if ($nuvalue != $value) {
 601                 $update[] = $this->config->{"field_map_$key"}."='".$this->ext_addslashes(core_text::convert($nuvalue, 'utf-8', $this->config->extencoding))."'";
 602             }
 603         }
 604         if (!empty($update)) {
 605             $authdb->Execute("UPDATE {$this->config->table}
 606                                  SET ".implode(',', $update)."
 607                                WHERE {$this->config->fielduser}='".$this->ext_addslashes($extusername)."'");
 608         }
 609         $authdb->Close();
 610         return true;
 611     }
 612
 613     /**
 614      * A chance to validate form data, and last chance to
 615      * do stuff before it is inserted in config_plugin
 616      *
 617      * @param stfdClass $form
 618      * @param array $err errors
 619      * @return void
 620      */
 621      function validate_form($form, &$err) {
 622         if ($form->passtype === 'internal') {
 623             $this->config->changepasswordurl = '';
 624             set_config('changepasswordurl', '', 'auth/db');
 625         }
 626     }
 627
 628     function prevent_local_passwords() {
 629         return !$this->is_internal();
 630     }
 631
 632     /**
 633      * Returns true if this authentication plugin is "internal".
 634      *
 635      * Internal plugins use password hashes from Moodle user table for authentication.
 636      *
 637      * @return bool
 638      */
 639     function is_internal() {
 640         if (!isset($this->config->passtype)) {
 641             return true;
 642         }
 643         return ($this->config->passtype === 'internal');
 644     }
 645
 646     /**
 647      * Indicates if moodle should automatically update internal user
 648      * records with data from external sources using the information
 649      * from auth_plugin_base::get_userinfo().
 650      *
 651      * @return bool true means automatically copy data from ext to user table
 652      */
 653     function is_synchronised_with_external() {
 654         return true;
 655     }
 656
 657     /**
 658      * Returns true if this authentication plugin can change the user's
 659      * password.
 660      *
 661      * @return bool
 662      */
 663     function can_change_password() {
 664         return ($this->is_internal() or !empty($this->config->changepasswordurl));
 665     }
 666
 667     /**
 668      * Returns the URL for changing the user's pw, or empty if the default can
 669      * be used.
 670      *
 671      * @return moodle_url
 672      */
 673     function change_password_url() {
 674         if ($this->is_internal() || empty($this->config->changepasswordurl)) {
 675             // Standard form.
 676             return null;
 677         } else {
 678             // Use admin defined custom url.
 679             return new moodle_url($this->config->changepasswordurl);
 680         }
 681     }
 682
 683     /**
 684      * Returns true if plugin allows resetting of internal password.
 685      *
 686      * @return bool
 687      */
 688     function can_reset_password() {
 689         return $this->is_internal();
 690     }
 691
 692     /**
 693      * Prints a form for configuring this authentication plugin.
 694      *
 695      * This function is called from admin/auth.php, and outputs a full page with
 696      * a form for configuring this plugin.
 697      *
 698      * @param stdClass $config
 699      * @param array $err errors
 700      * @param array $user_fields
 701      * @return void
 702      */
 703     function config_form($config, $err, $user_fields) {
 704         include 'config.html';
 705     }
 706
 707     /**
 708      * Processes and stores configuration data for this authentication plugin.
 709      *
 710      * @param srdClass $config
 711      * @return bool always true or exception
 712      */
 713     function process_config($config) {
 714         // set to defaults if undefined
 715         if (!isset($config->host)) {
 716             $config->host = 'localhost';
 717         }
 718         if (!isset($config->type)) {
 719             $config->type = 'mysql';
 720         }
 721         if (!isset($config->sybasequoting)) {
 722             $config->sybasequoting = 0;
 723         }
 724         if (!isset($config->name)) {
 725             $config->name = '';
 726         }
 727         if (!isset($config->user)) {
 728             $config->user = '';
 729         }
 730         if (!isset($config->pass)) {
 731             $config->pass = '';
 732         }
 733         if (!isset($config->table)) {
 734             $config->table = '';
 735         }
 736         if (!isset($config->fielduser)) {
 737             $config->fielduser = '';
 738         }
 739         if (!isset($config->fieldpass)) {
 740             $config->fieldpass = '';
 741         }
 742         if (!isset($config->passtype)) {
 743             $config->passtype = 'plaintext';
 744         }
 745         if (!isset($config->extencoding)) {
 746             $config->extencoding = 'utf-8';
 747         }
 748         if (!isset($config->setupsql)) {
 749             $config->setupsql = '';
 750         }
 751         if (!isset($config->debugauthdb)) {
 752             $config->debugauthdb = 0;
 753         }
 754         if (!isset($config->removeuser)) {
 755             $config->removeuser = AUTH_REMOVEUSER_KEEP;
 756         }
 757         if (!isset($config->changepasswordurl)) {
 758             $config->changepasswordurl = '';
 759         }
 760
 761         // Save settings.
 762         set_config('host',          $config->host,          'auth/db');
 763         set_config('type',          $config->type,          'auth/db');
 764         set_config('sybasequoting', $config->sybasequoting, 'auth/db');
 765         set_config('name',          $config->name,          'auth/db');
 766         set_config('user',          $config->user,          'auth/db');
 767         set_config('pass',          $config->pass,          'auth/db');
 768         set_config('table',         $config->table,         'auth/db');
 769         set_config('fielduser',     $config->fielduser,     'auth/db');
 770         set_config('fieldpass',     $config->fieldpass,     'auth/db');
 771         set_config('passtype',      $config->passtype,      'auth/db');
 772         set_config('extencoding',   trim($config->extencoding), 'auth/db');
 773         set_config('setupsql',      trim($config->setupsql),'auth/db');
 774         set_config('debugauthdb',   $config->debugauthdb,   'auth/db');
 775         set_config('removeuser',    $config->removeuser,    'auth/db');
 776         set_config('changepasswordurl', trim($config->changepasswordurl), 'auth/db');
 777
 778         return true;
 779     }
 780
 781     /**
 782      * Add slashes, we can not use placeholders or system functions.
 783      *
 784      * @param string $text
 785      * @return string
 786      */
 787     function ext_addslashes($text) {
 788         if (empty($this->config->sybasequoting)) {
 789             $text = str_replace('\\', '\\\\', $text);
 790             $text = str_replace(array('\'', '"', "\0"), array('\\\'', '\\"', '\\0'), $text);
 791         } else {
 792             $text = str_replace("'", "''", $text);
 793         }
 794         return $text;
 795     }
 796
 797     /**
 798      * Test if settings are ok, print info to output.
 799      * @private
 800      */
 801     public function test_settings() {
 802         global $CFG, $OUTPUT;
 803
 804         // NOTE: this is not localised intentionally, admins are supposed to understand English at least a bit...
 805
 806         raise_memory_limit(MEMORY_HUGE);
 807
 808         if (empty($this->config->table)) {
 809             echo $OUTPUT->notification('External table not specified.', 'notifyproblem');
 810             return;
 811         }
 812
 813         if (empty($this->config->fielduser)) {
 814             echo $OUTPUT->notification('External user field not specified.', 'notifyproblem');
 815             return;
 816         }
 817
 818         $olddebug = $CFG->debug;
 819         $olddisplay = ini_get('display_errors');
 820         ini_set('display_errors', '1');
 821         $CFG->debug = DEBUG_DEVELOPER;
 822         $olddebugauthdb = $this->config->debugauthdb;
 823         $this->config->debugauthdb = 1;
 824         error_reporting($CFG->debug);
 825
 826         $adodb = $this->db_init();
 827
 828         if (!$adodb or !$adodb->IsConnected()) {
 829             $this->config->debugauthdb = $olddebugauthdb;
 830             $CFG->debug = $olddebug;
 831             ini_set('display_errors', $olddisplay);
 832             error_reporting($CFG->debug);
 833             ob_end_flush();
 834
 835             echo $OUTPUT->notification('Cannot connect the database.', 'notifyproblem');
 836             return;
 837         }
 838
 839         $rs = $adodb->Execute("SELECT *
 840                                  FROM {$this->config->table}
 841                                 WHERE {$this->config->fielduser} <> 'random_unlikely_username'"); // Any unlikely name is ok here.
 842
 843         if (!$rs) {
 844             echo $OUTPUT->notification('Can not read external table.', 'notifyproblem');
 845
 846         } else if ($rs->EOF) {
 847             echo $OUTPUT->notification('External table is empty.', 'notifyproblem');
 848             $rs->close();
 849
 850         } else {
 851             $fields_obj = $rs->FetchObj();
 852             $columns = array_keys((array)$fields_obj);
 853
 854             echo $OUTPUT->notification('External table contains following columns:<br />'.implode(', ', $columns), 'notifysuccess');
 855             $rs->close();
 856         }
 857
 858         $adodb->Close();
 859
 860         $this->config->debugauthdb = $olddebugauthdb;
 861         $CFG->debug = $olddebug;
 862         ini_set('display_errors', $olddisplay);
 863         error_reporting($CFG->debug);
 864         ob_end_flush();
 865     }
 866 }
 867
 868