includes/session/SessionManager.php

   1 <?php
   2 /**
   3  * MediaWiki\Session entry point
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Session
  22  */
  23
  24 namespace MediaWiki\Session;
  25
  26 use Psr\Log\LoggerInterface;
  27 use BagOStuff;
  28 use Config;
  29 use FauxRequest;
  30 use Language;
  31 use Message;
  32 use User;
  33 use WebRequest;
  34
  35 /**
  36  * This serves as the entry point to the MediaWiki session handling system.
  37  *
  38  * @ingroup Session
  39  * @since 1.27
  40  */
  41 final class SessionManager implements SessionManagerInterface {
  42         /** @var SessionManager|null */
  43         private static $instance = null;
  44
  45         /** @var Session|null */
  46         private static $globalSession = null;
  47
  48         /** @var WebRequest|null */
  49         private static $globalSessionRequest = null;
  50
  51         /** @var LoggerInterface */
  52         private $logger;
  53
  54         /** @var Config */
  55         private $config;
  56
  57         /** @var BagOStuff|null */
  58         private $store;
  59
  60         /** @var SessionProvider[] */
  61         private $sessionProviders = null;
  62
  63         /** @var string[] */
  64         private $varyCookies = null;
  65
  66         /** @var array */
  67         private $varyHeaders = null;
  68
  69         /** @var SessionBackend[] */
  70         private $allSessionBackends = array();
  71
  72         /** @var SessionId[] */
  73         private $allSessionIds = array();
  74
  75         /** @var string[] */
  76         private $preventUsers = array();
  77
  78         /**
  79          * Get the global SessionManager
  80          * @return SessionManagerInterface
  81          *  (really a SessionManager, but this is to make IDEs less confused)
  82          */
  83         public static function singleton() {
  84                 if ( self::$instance === null ) {
  85                         self::$instance = new self();
  86                 }
  87                 return self::$instance;
  88         }
  89
  90         /**
  91          * Get the "global" session
  92          *
  93          * If PHP's session_id() has been set, returns that session. Otherwise
  94          * returns the session for RequestContext::getMain()->getRequest().
  95          *
  96          * @return Session
  97          */
  98         public static function getGlobalSession() {
  99                 if ( !PHPSessionHandler::isEnabled() ) {
 100                         $id = '';
 101                 } else {
 102                         $id = session_id();
 103                 }
 104
 105                 $request = \RequestContext::getMain()->getRequest();
 106                 if (
 107                         !self::$globalSession // No global session is set up yet
 108                         || self::$globalSessionRequest !== $request // The global WebRequest changed
 109                         || $id !== '' && self::$globalSession->getId() !== $id // Someone messed with session_id()
 110                 ) {
 111                         self::$globalSessionRequest = $request;
 112                         if ( $id === '' ) {
 113                                 // session_id() wasn't used, so fetch the Session from the WebRequest.
 114                                 // We use $request->getSession() instead of $singleton->getSessionForRequest()
 115                                 // because doing the latter would require a public
 116                                 // "$request->getSessionId()" method that would confuse end
 117                                 // users by returning SessionId|null where they'd expect it to
 118                                 // be short for $request->getSession()->getId(), and would
 119                                 // wind up being a duplicate of the code in
 120                                 // $request->getSession() anyway.
 121                                 self::$globalSession = $request->getSession();
 122                         } else {
 123                                 // Someone used session_id(), so we need to follow suit.
 124                                 // Note this overwrites whatever session might already be
 125                                 // associated with $request with the one for $id.
 126                                 self::$globalSession = self::singleton()->getSessionById( $id, true, $request )
 127                                         ?: $request->getSession();
 128                         }
 129                 }
 130                 return self::$globalSession;
 131         }
 132
 133         /**
 134          * @param array $options
 135          *  - config: Config to fetch configuration from. Defaults to the default 'main' config.
 136          *  - logger: LoggerInterface to use for logging. Defaults to the 'session' channel.
 137          *  - store: BagOStuff to store session data in.
 138          */
 139         public function __construct( $options = array() ) {
 140                 if ( isset( $options['config'] ) ) {
 141                         $this->config = $options['config'];
 142                         if ( !$this->config instanceof Config ) {
 143                                 throw new \InvalidArgumentException(
 144                                         '$options[\'config\'] must be an instance of Config'
 145                                 );
 146                         }
 147                 } else {
 148                         $this->config = \ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 149                 }
 150
 151                 if ( isset( $options['logger'] ) ) {
 152                         if ( !$options['logger'] instanceof LoggerInterface ) {
 153                                 throw new \InvalidArgumentException(
 154                                         '$options[\'logger\'] must be an instance of LoggerInterface'
 155                                 );
 156                         }
 157                         $this->setLogger( $options['logger'] );
 158                 } else {
 159                         $this->setLogger( \MediaWiki\Logger\LoggerFactory::getInstance( 'session' ) );
 160                 }
 161
 162                 if ( isset( $options['store'] ) ) {
 163                         if ( !$options['store'] instanceof BagOStuff ) {
 164                                 throw new \InvalidArgumentException(
 165                                         '$options[\'store\'] must be an instance of BagOStuff'
 166                                 );
 167                         }
 168                         $this->store = $options['store'];
 169                 } else {
 170                         $this->store = \ObjectCache::getInstance( $this->config->get( 'SessionCacheType' ) );
 171                         $this->store->setLogger( $this->logger );
 172                 }
 173
 174                 register_shutdown_function( array( $this, 'shutdown' ) );
 175         }
 176
 177         public function setLogger( LoggerInterface $logger ) {
 178                 $this->logger = $logger;
 179         }
 180
 181         public function getPersistedSessionId( WebRequest $request ) {
 182                 $info = $this->getSessionInfoForRequest( $request );
 183                 if ( $info && $info->wasPersisted() ) {
 184                         return $info->getId();
 185                 } else {
 186                         return null;
 187                 }
 188         }
 189
 190         public function getSessionForRequest( WebRequest $request ) {
 191                 $info = $this->getSessionInfoForRequest( $request );
 192
 193                 if ( !$info ) {
 194                         $session = $this->getEmptySession( $request );
 195                 } else {
 196                         $session = $this->getSessionFromInfo( $info, $request );
 197                 }
 198                 return $session;
 199         }
 200
 201         public function getSessionById( $id, $create = false, WebRequest $request = null ) {
 202                 if ( !self::validateSessionId( $id ) ) {
 203                         throw new \InvalidArgumentException( 'Invalid session ID' );
 204                 }
 205                 if ( !$request ) {
 206                         $request = new FauxRequest;
 207                 }
 208
 209                 $session = null;
 210
 211                 // Test this here to provide a better log message for the common case
 212                 // of "no such ID"
 213                 $key = wfMemcKey( 'MWSession', $id );
 214                 if ( is_array( $this->store->get( $key ) ) ) {
 215                         $info = new SessionInfo( SessionInfo::MIN_PRIORITY, array( 'id' => $id, 'idIsSafe' => true ) );
 216                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 217                                 $session = $this->getSessionFromInfo( $info, $request );
 218                         }
 219                 }
 220
 221                 if ( $create && $session === null ) {
 222                         $ex = null;
 223                         try {
 224                                 $session = $this->getEmptySessionInternal( $request, $id );
 225                         } catch ( \Exception $ex ) {
 226                                 $this->logger->error( __METHOD__ . ': failed to create empty session: ' .
 227                                         $ex->getMessage() );
 228                                 $session = null;
 229                         }
 230                 }
 231
 232                 return $session;
 233         }
 234
 235         public function getEmptySession( WebRequest $request = null ) {
 236                 return $this->getEmptySessionInternal( $request );
 237         }
 238
 239         /**
 240          * @see SessionManagerInterface::getEmptySession
 241          * @param WebRequest|null $request
 242          * @param string|null $id ID to force on the new session
 243          * @return Session
 244          */
 245         private function getEmptySessionInternal( WebRequest $request = null, $id = null ) {
 246                 if ( $id !== null ) {
 247                         if ( !self::validateSessionId( $id ) ) {
 248                                 throw new \InvalidArgumentException( 'Invalid session ID' );
 249                         }
 250
 251                         $key = wfMemcKey( 'MWSession', $id );
 252                         if ( is_array( $this->store->get( $key ) ) ) {
 253                                 throw new \InvalidArgumentException( 'Session ID already exists' );
 254                         }
 255                 }
 256                 if ( !$request ) {
 257                         $request = new FauxRequest;
 258                 }
 259
 260                 $infos = array();
 261                 foreach ( $this->getProviders() as $provider ) {
 262                         $info = $provider->newSessionInfo( $id );
 263                         if ( !$info ) {
 264                                 continue;
 265                         }
 266                         if ( $info->getProvider() !== $provider ) {
 267                                 throw new \UnexpectedValueException(
 268                                         "$provider returned an empty session info for a different provider: $info"
 269                                 );
 270                         }
 271                         if ( $id !== null && $info->getId() !== $id ) {
 272                                 throw new \UnexpectedValueException(
 273                                         "$provider returned empty session info with a wrong id: " .
 274                                                 $info->getId() . ' != ' . $id
 275                                 );
 276                         }
 277                         if ( !$info->isIdSafe() ) {
 278                                 throw new \UnexpectedValueException(
 279                                         "$provider returned empty session info with id flagged unsafe"
 280                                 );
 281                         }
 282                         $compare = $infos ? SessionInfo::compare( $infos[0], $info ) : -1;
 283                         if ( $compare > 0 ) {
 284                                 continue;
 285                         }
 286                         if ( $compare === 0 ) {
 287                                 $infos[] = $info;
 288                         } else {
 289                                 $infos = array( $info );
 290                         }
 291                 }
 292
 293                 // Make sure there's exactly one
 294                 if ( count( $infos ) > 1 ) {
 295                         throw new \UnexpectedValueException(
 296                                 'Multiple empty sessions tied for top priority: ' . join( ', ', $infos )
 297                         );
 298                 } elseif ( count( $infos ) < 1 ) {
 299                         throw new \UnexpectedValueException( 'No provider could provide an empty session!' );
 300                 }
 301
 302                 return $this->getSessionFromInfo( $infos[0], $request );
 303         }
 304
 305         public function getVaryHeaders() {
 306                 if ( $this->varyHeaders === null ) {
 307                         $headers = array();
 308                         foreach ( $this->getProviders() as $provider ) {
 309                                 foreach ( $provider->getVaryHeaders() as $header => $options ) {
 310                                         if ( !isset( $headers[$header] ) ) {
 311                                                 $headers[$header] = array();
 312                                         }
 313                                         if ( is_array( $options ) ) {
 314                                                 $headers[$header] = array_unique( array_merge( $headers[$header], $options ) );
 315                                         }
 316                                 }
 317                         }
 318                         $this->varyHeaders = $headers;
 319                 }
 320                 return $this->varyHeaders;
 321         }
 322
 323         public function getVaryCookies() {
 324                 if ( $this->varyCookies === null ) {
 325                         $cookies = array();
 326                         foreach ( $this->getProviders() as $provider ) {
 327                                 $cookies = array_merge( $cookies, $provider->getVaryCookies() );
 328                         }
 329                         $this->varyCookies = array_values( array_unique( $cookies ) );
 330                 }
 331                 return $this->varyCookies;
 332         }
 333
 334         /**
 335          * Validate a session ID
 336          * @param string $id
 337          * @return bool
 338          */
 339         public static function validateSessionId( $id ) {
 340                 return is_string( $id ) && preg_match( '/^[a-zA-Z0-9_-]{32,}$/', $id );
 341         }
 342
 343         /**
 344          * @name Internal methods
 345          * @{
 346          */
 347
 348         /**
 349          * Auto-create the given user, if necessary
 350          * @private Don't call this yourself. Let Setup.php do it for you at the right time.
 351          * @note This more properly belongs in AuthManager, but we need it now.
 352          *  When AuthManager comes, this will be deprecated and will pass-through
 353          *  to the corresponding AuthManager method.
 354          * @param User $user User to auto-create
 355          * @return bool Success
 356          */
 357         public static function autoCreateUser( User $user ) {
 358                 global $wgAuth;
 359
 360                 $logger = self::singleton()->logger;
 361
 362                 // Much of this code is based on that in CentralAuth
 363
 364                 // Try the local user from the slave DB
 365                 $localId = User::idFromName( $user->getName() );
 366
 367                 // Fetch the user ID from the master, so that we don't try to create the user
 368                 // when they already exist, due to replication lag
 369                 // @codeCoverageIgnoreStart
 370                 if ( !$localId && wfGetLB()->getReaderIndex() != 0 ) {
 371                         $localId = User::idFromName( $user->getName(), User::READ_LATEST );
 372                 }
 373                 // @codeCoverageIgnoreEnd
 374
 375                 if ( $localId ) {
 376                         // User exists after all.
 377                         $user->setId( $localId );
 378                         $user->loadFromId();
 379                         return false;
 380                 }
 381
 382                 // Denied by AuthPlugin? But ignore AuthPlugin itself.
 383                 if ( get_class( $wgAuth ) !== 'AuthPlugin' && !$wgAuth->autoCreate() ) {
 384                         $logger->debug( __METHOD__ . ': denied by AuthPlugin' );
 385                         $user->setId( 0 );
 386                         $user->loadFromId();
 387                         return false;
 388                 }
 389
 390                 // Wiki is read-only?
 391                 if ( wfReadOnly() ) {
 392                         $logger->debug( __METHOD__ . ': denied by wfReadOnly()' );
 393                         $user->setId( 0 );
 394                         $user->loadFromId();
 395                         return false;
 396                 }
 397
 398                 $userName = $user->getName();
 399
 400                 // Check the session, if we tried to create this user already there's
 401                 // no point in retrying.
 402                 $session = self::getGlobalSession();
 403                 $reason = $session->get( 'MWSession::AutoCreateBlacklist' );
 404                 if ( $reason ) {
 405                         $logger->debug( __METHOD__ . ": blacklisted in session ($reason)" );
 406                         $user->setId( 0 );
 407                         $user->loadFromId();
 408                         return false;
 409                 }
 410
 411                 // Is the IP user able to create accounts?
 412                 $anon = new User;
 413                 if ( !$anon->isAllowedAny( 'createaccount', 'autocreateaccount' )
 414                         || $anon->isBlockedFromCreateAccount()
 415                 ) {
 416                         // Blacklist the user to avoid repeated DB queries subsequently
 417                         $logger->debug( __METHOD__ . ': user is blocked from this wiki, blacklisting' );
 418                         $session->set( 'MWSession::AutoCreateBlacklist', 'blocked', 600 );
 419                         $session->persist();
 420                         $user->setId( 0 );
 421                         $user->loadFromId();
 422                         return false;
 423                 }
 424
 425                 // Check for validity of username
 426                 if ( !User::isCreatableName( $userName ) ) {
 427                         $logger->debug( __METHOD__ . ': Invalid username, blacklisting' );
 428                         $session->set( 'MWSession::AutoCreateBlacklist', 'invalid username', 600 );
 429                         $session->persist();
 430                         $user->setId( 0 );
 431                         $user->loadFromId();
 432                         return false;
 433                 }
 434
 435                 // Give other extensions a chance to stop auto creation.
 436                 $user->loadDefaults( $userName );
 437                 $abortMessage = '';
 438                 if ( !\Hooks::run( 'AbortAutoAccount', array( $user, &$abortMessage ) ) ) {
 439                         // In this case we have no way to return the message to the user,
 440                         // but we can log it.
 441                         $logger->debug( __METHOD__ . ": denied by hook: $abortMessage" );
 442                         $session->set( 'MWSession::AutoCreateBlacklist', "hook aborted: $abortMessage", 600 );
 443                         $session->persist();
 444                         $user->setId( 0 );
 445                         $user->loadFromId();
 446                         return false;
 447                 }
 448
 449                 // Make sure the name has not been changed
 450                 if ( $user->getName() !== $userName ) {
 451                         $user->setId( 0 );
 452                         $user->loadFromId();
 453                         throw new \UnexpectedValueException(
 454                                 'AbortAutoAccount hook tried to change the user name'
 455                         );
 456                 }
 457
 458                 // Ignore warnings about master connections/writes...hard to avoid here
 459                 \Profiler::instance()->getTransactionProfiler()->resetExpectations();
 460
 461                 $cache = \ObjectCache::getLocalClusterInstance();
 462                 $backoffKey = wfMemcKey( 'MWSession', 'autocreate-failed', md5( $userName ) );
 463                 if ( $cache->get( $backoffKey ) ) {
 464                         $logger->debug( __METHOD__ . ': denied by prior creation attempt failures' );
 465                         $user->setId( 0 );
 466                         $user->loadFromId();
 467                         return false;
 468                 }
 469
 470                 // Checks passed, create the user...
 471                 $from = isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : 'CLI';
 472                 $logger->info( __METHOD__ . ": creating new user ($userName) - from: $from" );
 473
 474                 try {
 475                         // Insert the user into the local DB master
 476                         $status = $user->addToDatabase();
 477                         if ( !$status->isOK() ) {
 478                                 // @codeCoverageIgnoreStart
 479                                 $logger->error( __METHOD__ . ': failed with message ' . $status->getWikiText() );
 480                                 $user->setId( 0 );
 481                                 $user->loadFromId();
 482                                 return false;
 483                                 // @codeCoverageIgnoreEnd
 484                         }
 485                 } catch ( \Exception $ex ) {
 486                         // @codeCoverageIgnoreStart
 487                         $logger->error( __METHOD__ . ': failed with exception ' . $ex->getMessage() );
 488                         // Do not keep throwing errors for a while
 489                         $cache->set( $backoffKey, 1, 600 );
 490                         // Bubble up error; which should normally trigger DB rollbacks
 491                         throw $ex;
 492                         // @codeCoverageIgnoreEnd
 493                 }
 494
 495                 # Notify hooks (e.g. Newuserlog)
 496                 \Hooks::run( 'AuthPluginAutoCreate', array( $user ) );
 497                 \Hooks::run( 'LocalUserCreated', array( $user, true ) );
 498
 499                 # Update user count
 500                 \DeferredUpdates::addUpdate( new \SiteStatsUpdate( 0, 0, 0, 0, 1 ) );
 501
 502                 # Watch user's userpage and talk page
 503                 $user->addWatch( $user->getUserPage(), \WatchedItem::IGNORE_USER_RIGHTS );
 504
 505                 return true;
 506         }
 507
 508         /**
 509          * Prevent future sessions for the user
 510          *
 511          * The intention is that the named account will never again be usable for
 512          * normal login (i.e. there is no way to undo the prevention of access).
 513          *
 514          * @private For use from \\User::newSystemUser only
 515          * @param string $username
 516          */
 517         public function preventSessionsForUser( $username ) {
 518                 $this->preventUsers[$username] = true;
 519
 520                 // Reset the user's token to kill existing sessions
 521                 $user = User::newFromName( $username );
 522                 if ( $user && $user->getToken() ) {
 523                         $user->setToken( true );
 524                         $user->saveSettings();
 525                 }
 526
 527                 // Instruct the session providers to kill any other sessions too.
 528                 foreach ( $this->getProviders() as $provider ) {
 529                         $provider->preventSessionsForUser( $username );
 530                 }
 531         }
 532
 533         /**
 534          * Test if a user is prevented
 535          * @private For use from SessionBackend only
 536          * @param string $username
 537          * @return bool
 538          */
 539         public function isUserSessionPrevented( $username ) {
 540                 return !empty( $this->preventUsers[$username] );
 541         }
 542
 543         /**
 544          * Get the available SessionProviders
 545          * @return SessionProvider[]
 546          */
 547         protected function getProviders() {
 548                 if ( $this->sessionProviders === null ) {
 549                         $this->sessionProviders = array();
 550                         foreach ( $this->config->get( 'SessionProviders' ) as $spec ) {
 551                                 $provider = \ObjectFactory::getObjectFromSpec( $spec );
 552                                 $provider->setLogger( $this->logger );
 553                                 $provider->setConfig( $this->config );
 554                                 $provider->setManager( $this );
 555                                 if ( isset( $this->sessionProviders[(string)$provider] ) ) {
 556                                         throw new \UnexpectedValueException( "Duplicate provider name \"$provider\"" );
 557                                 }
 558                                 $this->sessionProviders[(string)$provider] = $provider;
 559                         }
 560                 }
 561                 return $this->sessionProviders;
 562         }
 563
 564         /**
 565          * Get a session provider by name
 566          *
 567          * Generally, this will only be used by internal implementation of some
 568          * special session-providing mechanism. General purpose code, if it needs
 569          * to access a SessionProvider at all, will use Session::getProvider().
 570          *
 571          * @param string $name
 572          * @return SessionProvider|null
 573          */
 574         public function getProvider( $name ) {
 575                 $providers = $this->getProviders();
 576                 return isset( $providers[$name] ) ? $providers[$name] : null;
 577         }
 578
 579         /**
 580          * Save all active sessions on shutdown
 581          * @private For internal use with register_shutdown_function()
 582          */
 583         public function shutdown() {
 584                 if ( $this->allSessionBackends ) {
 585                         $this->logger->debug( 'Saving all sessions on shutdown' );
 586                         if ( session_id() !== '' ) {
 587                                 // @codeCoverageIgnoreStart
 588                                 session_write_close();
 589                         }
 590                         // @codeCoverageIgnoreEnd
 591                         foreach ( $this->allSessionBackends as $backend ) {
 592                                 $backend->save( true );
 593                         }
 594                 }
 595         }
 596
 597         /**
 598          * Fetch the SessionInfo(s) for a request
 599          * @param WebRequest $request
 600          * @return SessionInfo|null
 601          */
 602         private function getSessionInfoForRequest( WebRequest $request ) {
 603                 // Call all providers to fetch "the" session
 604                 $infos = array();
 605                 foreach ( $this->getProviders() as $provider ) {
 606                         $info = $provider->provideSessionInfo( $request );
 607                         if ( !$info ) {
 608                                 continue;
 609                         }
 610                         if ( $info->getProvider() !== $provider ) {
 611                                 throw new \UnexpectedValueException(
 612                                         "$provider returned session info for a different provider: $info"
 613                                 );
 614                         }
 615                         $infos[] = $info;
 616                 }
 617
 618                 // Sort the SessionInfos. Then find the first one that can be
 619                 // successfully loaded, and then all the ones after it with the same
 620                 // priority.
 621                 usort( $infos, 'MediaWiki\\Session\\SessionInfo::compare' );
 622                 $retInfos = array();
 623                 while ( $infos ) {
 624                         $info = array_pop( $infos );
 625                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 626                                 $retInfos[] = $info;
 627                                 while ( $infos ) {
 628                                         $info = array_pop( $infos );
 629                                         if ( SessionInfo::compare( $retInfos[0], $info ) ) {
 630                                                 // We hit a lower priority, stop checking.
 631                                                 break;
 632                                         }
 633                                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 634                                                 // This is going to error out below, but we want to
 635                                                 // provide a complete list.
 636                                                 $retInfos[] = $info;
 637                                         }
 638                                 }
 639                         }
 640                 }
 641
 642                 if ( count( $retInfos ) > 1 ) {
 643                         $ex = new \OverflowException(
 644                                 'Multiple sessions for this request tied for top priority: ' . join( ', ', $retInfos )
 645                         );
 646                         $ex->sessionInfos = $retInfos;
 647                         throw $ex;
 648                 }
 649
 650                 return $retInfos ? $retInfos[0] : null;
 651         }
 652
 653         /**
 654          * Load and verify the session info against the store
 655          *
 656          * @param SessionInfo &$info Will likely be replaced with an updated SessionInfo instance
 657          * @param WebRequest $request
 658          * @return bool Whether the session info matches the stored data (if any)
 659          */
 660         private function loadSessionInfoFromStore( SessionInfo &$info, WebRequest $request ) {
 661                 $key = wfMemcKey( 'MWSession', $info->getId() );
 662                 $blob = $this->store->get( $key );
 663
 664                 $newParams = array();
 665
 666                 if ( $blob !== false ) {
 667                         // Sanity check: blob must be an array, if it's saved at all
 668                         if ( !is_array( $blob ) ) {
 669                                 $this->logger->warning( "Session $info: Bad data" );
 670                                 $this->store->delete( $key );
 671                                 return false;
 672                         }
 673
 674                         // Sanity check: blob has data and metadata arrays
 675                         if ( !isset( $blob['data'] ) || !is_array( $blob['data'] ) ||
 676                                 !isset( $blob['metadata'] ) || !is_array( $blob['metadata'] )
 677                         ) {
 678                                 $this->logger->warning( "Session $info: Bad data structure" );
 679                                 $this->store->delete( $key );
 680                                 return false;
 681                         }
 682
 683                         $data = $blob['data'];
 684                         $metadata = $blob['metadata'];
 685
 686                         // Sanity check: metadata must be an array and must contain certain
 687                         // keys, if it's saved at all
 688                         if ( !array_key_exists( 'userId', $metadata ) ||
 689                                 !array_key_exists( 'userName', $metadata ) ||
 690                                 !array_key_exists( 'userToken', $metadata ) ||
 691                                 !array_key_exists( 'provider', $metadata )
 692                         ) {
 693                                 $this->logger->warning( "Session $info: Bad metadata" );
 694                                 $this->store->delete( $key );
 695                                 return false;
 696                         }
 697
 698                         // First, load the provider from metadata, or validate it against the metadata.
 699                         $provider = $info->getProvider();
 700                         if ( $provider === null ) {
 701                                 $newParams['provider'] = $provider = $this->getProvider( $metadata['provider'] );
 702                                 if ( !$provider ) {
 703                                         $this->logger->warning( "Session $info: Unknown provider, " . $metadata['provider'] );
 704                                         $this->store->delete( $key );
 705                                         return false;
 706                                 }
 707                         } elseif ( $metadata['provider'] !== (string)$provider ) {
 708                                 $this->logger->warning( "Session $info: Wrong provider, " .
 709                                         $metadata['provider'] . ' !== ' . $provider );
 710                                 return false;
 711                         }
 712
 713                         // Load provider metadata from metadata, or validate it against the metadata
 714                         $providerMetadata = $info->getProviderMetadata();
 715                         if ( isset( $metadata['providerMetadata'] ) ) {
 716                                 if ( $providerMetadata === null ) {
 717                                         $newParams['metadata'] = $metadata['providerMetadata'];
 718                                 } else {
 719                                         try {
 720                                                 $newProviderMetadata = $provider->mergeMetadata(
 721                                                         $metadata['providerMetadata'], $providerMetadata
 722                                                 );
 723                                                 if ( $newProviderMetadata !== $providerMetadata ) {
 724                                                         $newParams['metadata'] = $newProviderMetadata;
 725                                                 }
 726                                         } catch ( \UnexpectedValueException $ex ) {
 727                                                 $this->logger->warning( "Session $info: Metadata merge failed: " . $ex->getMessage() );
 728                                                 return false;
 729                                         }
 730                                 }
 731                         }
 732
 733                         // Next, load the user from metadata, or validate it against the metadata.
 734                         $userInfo = $info->getUserInfo();
 735                         if ( !$userInfo ) {
 736                                 // For loading, id is preferred to name.
 737                                 try {
 738                                         if ( $metadata['userId'] ) {
 739                                                 $userInfo = UserInfo::newFromId( $metadata['userId'] );
 740                                         } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 741                                                 $userInfo = UserInfo::newFromName( $metadata['userName'] );
 742                                         } else {
 743                                                 $userInfo = UserInfo::newAnonymous();
 744                                         }
 745                                 } catch ( \InvalidArgumentException $ex ) {
 746                                         $this->logger->error( "Session $info: " . $ex->getMessage() );
 747                                         return false;
 748                                 }
 749                                 $newParams['userInfo'] = $userInfo;
 750                         } else {
 751                                 // User validation passes if user ID matches, or if there
 752                                 // is no saved ID and the names match.
 753                                 if ( $metadata['userId'] ) {
 754                                         if ( $metadata['userId'] !== $userInfo->getId() ) {
 755                                                 $this->logger->warning( "Session $info: User ID mismatch, " .
 756                                                         $metadata['userId'] . ' !== ' . $userInfo->getId() );
 757                                                 return false;
 758                                         }
 759
 760                                         // If the user was renamed, probably best to fail here.
 761                                         if ( $metadata['userName'] !== null &&
 762                                                 $userInfo->getName() !== $metadata['userName']
 763                                         ) {
 764                                                 $this->logger->warning( "Session $info: User ID matched but name didn't (rename?), " .
 765                                                         $metadata['userName'] . ' !== ' . $userInfo->getName() );
 766                                                 return false;
 767                                         }
 768
 769                                 } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 770                                         if ( $metadata['userName'] !== $userInfo->getName() ) {
 771                                                 $this->logger->warning( "Session $info: User name mismatch, " .
 772                                                         $metadata['userName'] . ' !== ' . $userInfo->getName() );
 773                                                 return false;
 774                                         }
 775                                 } elseif ( !$userInfo->isAnon() ) {
 776                                         // Metadata specifies an anonymous user, but the passed-in
 777                                         // user isn't anonymous.
 778                                         $this->logger->warning(
 779                                                 "Session $info: Metadata has an anonymous user, " .
 780                                                         'but a non-anon user was provided'
 781                                         );
 782                                         return false;
 783                                 }
 784                         }
 785
 786                         // And if we have a token in the metadata, it must match the loaded/provided user.
 787                         if ( $metadata['userToken'] !== null &&
 788                                 $userInfo->getToken() !== $metadata['userToken']
 789                         ) {
 790                                 $this->logger->warning( "Session $info: User token mismatch" );
 791                                 return false;
 792                         }
 793                         if ( !$userInfo->isVerified() ) {
 794                                 $newParams['userInfo'] = $userInfo->verified();
 795                         }
 796
 797                         if ( !empty( $metadata['remember'] ) && !$info->wasRemembered() ) {
 798                                 $newParams['remembered'] = true;
 799                         }
 800                         if ( !empty( $metadata['forceHTTPS'] ) && !$info->forceHTTPS() ) {
 801                                 $newParams['forceHTTPS'] = true;
 802                         }
 803
 804                         if ( !$info->isIdSafe() ) {
 805                                 $newParams['idIsSafe'] = true;
 806                         }
 807                 } else {
 808                         // No metadata, so we can't load the provider if one wasn't given.
 809                         if ( $info->getProvider() === null ) {
 810                                 $this->logger->warning( "Session $info: Null provider and no metadata" );
 811                                 return false;
 812                         }
 813
 814                         // If no user was provided and no metadata, it must be anon.
 815                         if ( !$info->getUserInfo() ) {
 816                                 if ( $info->getProvider()->canChangeUser() ) {
 817                                         $newParams['userInfo'] = UserInfo::newAnonymous();
 818                                 } else {
 819                                         $this->logger->info(
 820                                                 "Session $info: No user provided and provider cannot set user"
 821                                         );
 822                                         return false;
 823                                 }
 824                         } elseif ( !$info->getUserInfo()->isVerified() ) {
 825                                 $this->logger->warning(
 826                                         "Session $info: Unverified user provided and no metadata to auth it"
 827                                 );
 828                                 return false;
 829                         }
 830
 831                         $data = false;
 832                         $metadata = false;
 833
 834                         if ( !$info->getProvider()->persistsSessionId() && !$info->isIdSafe() ) {
 835                                 // The ID doesn't come from the user, so it should be safe
 836                                 // (and if not, nothing we can do about it anyway)
 837                                 $newParams['idIsSafe'] = true;
 838                         }
 839                 }
 840
 841                 // Construct the replacement SessionInfo, if necessary
 842                 if ( $newParams ) {
 843                         $newParams['copyFrom'] = $info;
 844                         $info = new SessionInfo( $info->getPriority(), $newParams );
 845                 }
 846
 847                 // Allow the provider to check the loaded SessionInfo
 848                 $providerMetadata = $info->getProviderMetadata();
 849                 if ( !$info->getProvider()->refreshSessionInfo( $info, $request, $providerMetadata ) ) {
 850                         return false;
 851                 }
 852                 if ( $providerMetadata !== $info->getProviderMetadata() ) {
 853                         $info = new SessionInfo( $info->getPriority(), array(
 854                                 'metadata' => $providerMetadata,
 855                                 'copyFrom' => $info,
 856                         ) );
 857                 }
 858
 859                 // Give hooks a chance to abort. Combined with the SessionMetadata
 860                 // hook, this can allow for tying a session to an IP address or the
 861                 // like.
 862                 $reason = 'Hook aborted';
 863                 if ( !\Hooks::run(
 864                         'SessionCheckInfo',
 865                         array( &$reason, $info, $request, $metadata, $data )
 866                 ) ) {
 867                         $this->logger->warning( "Session $info: $reason" );
 868                         return false;
 869                 }
 870
 871                 return true;
 872         }
 873
 874         /**
 875          * Create a session corresponding to the passed SessionInfo
 876          * @private For use by a SessionProvider that needs to specially create its
 877          *  own session.
 878          * @param SessionInfo $info
 879          * @param WebRequest $request
 880          * @return Session
 881          */
 882         public function getSessionFromInfo( SessionInfo $info, WebRequest $request ) {
 883                 $id = $info->getId();
 884
 885                 if ( !isset( $this->allSessionBackends[$id] ) ) {
 886                         if ( !isset( $this->allSessionIds[$id] ) ) {
 887                                 $this->allSessionIds[$id] = new SessionId( $id );
 888                         }
 889                         $backend = new SessionBackend(
 890                                 $this->allSessionIds[$id],
 891                                 $info,
 892                                 $this->store,
 893                                 $this->logger,
 894                                 $this->config->get( 'ObjectCacheSessionExpiry' )
 895                         );
 896                         $this->allSessionBackends[$id] = $backend;
 897                         $delay = $backend->delaySave();
 898                 } else {
 899                         $backend = $this->allSessionBackends[$id];
 900                         $delay = $backend->delaySave();
 901                         if ( $info->wasPersisted() ) {
 902                                 $backend->persist();
 903                         }
 904                         if ( $info->wasRemembered() ) {
 905                                 $backend->setRememberUser( true );
 906                         }
 907                 }
 908
 909                 $request->setSessionId( $backend->getSessionId() );
 910                 $session = $backend->getSession( $request );
 911
 912                 if ( !$info->isIdSafe() ) {
 913                         $session->resetId();
 914                 }
 915
 916                 \ScopedCallback::consume( $delay );
 917                 return $session;
 918         }
 919
 920         /**
 921          * Deregister a SessionBackend
 922          * @private For use from \\MediaWiki\\Session\\SessionBackend only
 923          * @param SessionBackend $backend
 924          */
 925         public function deregisterSessionBackend( SessionBackend $backend ) {
 926                 $id = $backend->getId();
 927                 if ( !isset( $this->allSessionBackends[$id] ) || !isset( $this->allSessionIds[$id] ) ||
 928                         $this->allSessionBackends[$id] !== $backend ||
 929                         $this->allSessionIds[$id] !== $backend->getSessionId()
 930                 ) {
 931                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
 932                 }
 933
 934                 unset( $this->allSessionBackends[$id] );
 935                 // Explicitly do not unset $this->allSessionIds[$id]
 936         }
 937
 938         /**
 939          * Change a SessionBackend's ID
 940          * @private For use from \\MediaWiki\\Session\\SessionBackend only
 941          * @param SessionBackend $backend
 942          */
 943         public function changeBackendId( SessionBackend $backend ) {
 944                 $sessionId = $backend->getSessionId();
 945                 $oldId = (string)$sessionId;
 946                 if ( !isset( $this->allSessionBackends[$oldId] ) || !isset( $this->allSessionIds[$oldId] ) ||
 947                         $this->allSessionBackends[$oldId] !== $backend ||
 948                         $this->allSessionIds[$oldId] !== $sessionId
 949                 ) {
 950                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
 951                 }
 952
 953                 $newId = $this->generateSessionId();
 954
 955                 unset( $this->allSessionBackends[$oldId], $this->allSessionIds[$oldId] );
 956                 $sessionId->setId( $newId );
 957                 $this->allSessionBackends[$newId] = $backend;
 958                 $this->allSessionIds[$newId] = $sessionId;
 959         }
 960
 961         /**
 962          * Generate a new random session ID
 963          * @return string
 964          */
 965         public function generateSessionId() {
 966                 do {
 967                         $id = wfBaseConvert( \MWCryptRand::generateHex( 40 ), 16, 32, 32 );
 968                         $key = wfMemcKey( 'MWSession', $id );
 969                 } while ( isset( $this->allSessionIds[$id] ) || is_array( $this->store->get( $key ) ) );
 970                 return $id;
 971         }
 972
 973         /**
 974          * Call setters on a PHPSessionHandler
 975          * @private Use PhpSessionHandler::install()
 976          * @param PHPSessionHandler $handler
 977          */
 978         public function setupPHPSessionHandler( PHPSessionHandler $handler ) {
 979                 $handler->setManager( $this, $this->store, $this->logger );
 980         }
 981
 982         /**
 983          * Reset the internal caching for unit testing
 984          */
 985         public static function resetCache() {
 986                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 987                         // @codeCoverageIgnoreStart
 988                         throw new MWException( __METHOD__ . ' may only be called from unit tests!' );
 989                         // @codeCoverageIgnoreEnd
 990                 }
 991
 992                 self::$globalSession = null;
 993                 self::$globalSessionRequest = null;
 994         }
 995
 996         /**@}*/
 997
 998 }