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 CachedBagOStuff;
  29 use Config;
  30 use FauxRequest;
  31 use User;
  32 use WebRequest;
  33
  34 /**
  35  * This serves as the entry point to the MediaWiki session handling system.
  36  *
  37  * @ingroup Session
  38  * @since 1.27
  39  */
  40 final class SessionManager implements SessionManagerInterface {
  41         /** @var SessionManager|null */
  42         private static $instance = null;
  43
  44         /** @var Session|null */
  45         private static $globalSession = null;
  46
  47         /** @var WebRequest|null */
  48         private static $globalSessionRequest = null;
  49
  50         /** @var LoggerInterface */
  51         private $logger;
  52
  53         /** @var Config */
  54         private $config;
  55
  56         /** @var CachedBagOStuff|null */
  57         private $store;
  58
  59         /** @var SessionProvider[] */
  60         private $sessionProviders = null;
  61
  62         /** @var string[] */
  63         private $varyCookies = null;
  64
  65         /** @var array */
  66         private $varyHeaders = null;
  67
  68         /** @var SessionBackend[] */
  69         private $allSessionBackends = [];
  70
  71         /** @var SessionId[] */
  72         private $allSessionIds = [];
  73
  74         /** @var string[] */
  75         private $preventUsers = [];
  76
  77         /**
  78          * Get the global SessionManager
  79          * @return SessionManagerInterface
  80          *  (really a SessionManager, but this is to make IDEs less confused)
  81          */
  82         public static function singleton() {
  83                 if ( self::$instance === null ) {
  84                         self::$instance = new self();
  85                 }
  86                 return self::$instance;
  87         }
  88
  89         /**
  90          * Get the "global" session
  91          *
  92          * If PHP's session_id() has been set, returns that session. Otherwise
  93          * returns the session for RequestContext::getMain()->getRequest().
  94          *
  95          * @return Session
  96          */
  97         public static function getGlobalSession() {
  98                 if ( !PHPSessionHandler::isEnabled() ) {
  99                         $id = '';
 100                 } else {
 101                         $id = session_id();
 102                 }
 103
 104                 $request = \RequestContext::getMain()->getRequest();
 105                 if (
 106                         !self::$globalSession // No global session is set up yet
 107                         || self::$globalSessionRequest !== $request // The global WebRequest changed
 108                         || $id !== '' && self::$globalSession->getId() !== $id // Someone messed with session_id()
 109                 ) {
 110                         self::$globalSessionRequest = $request;
 111                         if ( $id === '' ) {
 112                                 // session_id() wasn't used, so fetch the Session from the WebRequest.
 113                                 // We use $request->getSession() instead of $singleton->getSessionForRequest()
 114                                 // because doing the latter would require a public
 115                                 // "$request->getSessionId()" method that would confuse end
 116                                 // users by returning SessionId|null where they'd expect it to
 117                                 // be short for $request->getSession()->getId(), and would
 118                                 // wind up being a duplicate of the code in
 119                                 // $request->getSession() anyway.
 120                                 self::$globalSession = $request->getSession();
 121                         } else {
 122                                 // Someone used session_id(), so we need to follow suit.
 123                                 // Note this overwrites whatever session might already be
 124                                 // associated with $request with the one for $id.
 125                                 self::$globalSession = self::singleton()->getSessionById( $id, true, $request )
 126                                         ?: $request->getSession();
 127                         }
 128                 }
 129                 return self::$globalSession;
 130         }
 131
 132         /**
 133          * @param array $options
 134          *  - config: Config to fetch configuration from. Defaults to the default 'main' config.
 135          *  - logger: LoggerInterface to use for logging. Defaults to the 'session' channel.
 136          *  - store: BagOStuff to store session data in.
 137          */
 138         public function __construct( $options = [] ) {
 139                 if ( isset( $options['config'] ) ) {
 140                         $this->config = $options['config'];
 141                         if ( !$this->config instanceof Config ) {
 142                                 throw new \InvalidArgumentException(
 143                                         '$options[\'config\'] must be an instance of Config'
 144                                 );
 145                         }
 146                 } else {
 147                         $this->config = \ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 148                 }
 149
 150                 if ( isset( $options['logger'] ) ) {
 151                         if ( !$options['logger'] instanceof LoggerInterface ) {
 152                                 throw new \InvalidArgumentException(
 153                                         '$options[\'logger\'] must be an instance of LoggerInterface'
 154                                 );
 155                         }
 156                         $this->setLogger( $options['logger'] );
 157                 } else {
 158                         $this->setLogger( \MediaWiki\Logger\LoggerFactory::getInstance( 'session' ) );
 159                 }
 160
 161                 if ( isset( $options['store'] ) ) {
 162                         if ( !$options['store'] instanceof BagOStuff ) {
 163                                 throw new \InvalidArgumentException(
 164                                         '$options[\'store\'] must be an instance of BagOStuff'
 165                                 );
 166                         }
 167                         $store = $options['store'];
 168                 } else {
 169                         $store = \ObjectCache::getInstance( $this->config->get( 'SessionCacheType' ) );
 170                 }
 171                 $this->store = $store instanceof CachedBagOStuff ? $store : new CachedBagOStuff( $store );
 172
 173                 register_shutdown_function( [ $this, 'shutdown' ] );
 174         }
 175
 176         public function setLogger( LoggerInterface $logger ) {
 177                 $this->logger = $logger;
 178         }
 179
 180         public function getSessionForRequest( WebRequest $request ) {
 181                 $info = $this->getSessionInfoForRequest( $request );
 182
 183                 if ( !$info ) {
 184                         $session = $this->getEmptySession( $request );
 185                 } else {
 186                         $session = $this->getSessionFromInfo( $info, $request );
 187                 }
 188                 return $session;
 189         }
 190
 191         public function getSessionById( $id, $create = false, WebRequest $request = null ) {
 192                 if ( !self::validateSessionId( $id ) ) {
 193                         throw new \InvalidArgumentException( 'Invalid session ID' );
 194                 }
 195                 if ( !$request ) {
 196                         $request = new FauxRequest;
 197                 }
 198
 199                 $session = null;
 200
 201                 // Test this here to provide a better log message for the common case
 202                 // of "no such ID"
 203                 $key = wfMemcKey( 'MWSession', $id );
 204                 if ( is_array( $this->store->get( $key ) ) ) {
 205                         $info = new SessionInfo( SessionInfo::MIN_PRIORITY, [ 'id' => $id, 'idIsSafe' => true ] );
 206                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 207                                 $session = $this->getSessionFromInfo( $info, $request );
 208                         }
 209                 }
 210
 211                 if ( $create && $session === null ) {
 212                         $ex = null;
 213                         try {
 214                                 $session = $this->getEmptySessionInternal( $request, $id );
 215                         } catch ( \Exception $ex ) {
 216                                 $this->logger->error( 'Failed to create empty session: {exception}',
 217                                         [
 218                                                 'method' => __METHOD__,
 219                                                 'exception' => $ex,
 220                                 ] );
 221                                 $session = null;
 222                         }
 223                 }
 224
 225                 return $session;
 226         }
 227
 228         public function getEmptySession( WebRequest $request = null ) {
 229                 return $this->getEmptySessionInternal( $request );
 230         }
 231
 232         /**
 233          * @see SessionManagerInterface::getEmptySession
 234          * @param WebRequest|null $request
 235          * @param string|null $id ID to force on the new session
 236          * @return Session
 237          */
 238         private function getEmptySessionInternal( WebRequest $request = null, $id = null ) {
 239                 if ( $id !== null ) {
 240                         if ( !self::validateSessionId( $id ) ) {
 241                                 throw new \InvalidArgumentException( 'Invalid session ID' );
 242                         }
 243
 244                         $key = wfMemcKey( 'MWSession', $id );
 245                         if ( is_array( $this->store->get( $key ) ) ) {
 246                                 throw new \InvalidArgumentException( 'Session ID already exists' );
 247                         }
 248                 }
 249                 if ( !$request ) {
 250                         $request = new FauxRequest;
 251                 }
 252
 253                 $infos = [];
 254                 foreach ( $this->getProviders() as $provider ) {
 255                         $info = $provider->newSessionInfo( $id );
 256                         if ( !$info ) {
 257                                 continue;
 258                         }
 259                         if ( $info->getProvider() !== $provider ) {
 260                                 throw new \UnexpectedValueException(
 261                                         "$provider returned an empty session info for a different provider: $info"
 262                                 );
 263                         }
 264                         if ( $id !== null && $info->getId() !== $id ) {
 265                                 throw new \UnexpectedValueException(
 266                                         "$provider returned empty session info with a wrong id: " .
 267                                                 $info->getId() . ' != ' . $id
 268                                 );
 269                         }
 270                         if ( !$info->isIdSafe() ) {
 271                                 throw new \UnexpectedValueException(
 272                                         "$provider returned empty session info with id flagged unsafe"
 273                                 );
 274                         }
 275                         $compare = $infos ? SessionInfo::compare( $infos[0], $info ) : -1;
 276                         if ( $compare > 0 ) {
 277                                 continue;
 278                         }
 279                         if ( $compare === 0 ) {
 280                                 $infos[] = $info;
 281                         } else {
 282                                 $infos = [ $info ];
 283                         }
 284                 }
 285
 286                 // Make sure there's exactly one
 287                 if ( count( $infos ) > 1 ) {
 288                         throw new \UnexpectedValueException(
 289                                 'Multiple empty sessions tied for top priority: ' . join( ', ', $infos )
 290                         );
 291                 } elseif ( count( $infos ) < 1 ) {
 292                         throw new \UnexpectedValueException( 'No provider could provide an empty session!' );
 293                 }
 294
 295                 return $this->getSessionFromInfo( $infos[0], $request );
 296         }
 297
 298         public function getVaryHeaders() {
 299                 // @codeCoverageIgnoreStart
 300                 if ( defined( 'MW_NO_SESSION' ) && MW_NO_SESSION !== 'warn' ) {
 301                         return [];
 302                 }
 303                 // @codeCoverageIgnoreEnd
 304                 if ( $this->varyHeaders === null ) {
 305                         $headers = [];
 306                         foreach ( $this->getProviders() as $provider ) {
 307                                 foreach ( $provider->getVaryHeaders() as $header => $options ) {
 308                                         if ( !isset( $headers[$header] ) ) {
 309                                                 $headers[$header] = [];
 310                                         }
 311                                         if ( is_array( $options ) ) {
 312                                                 $headers[$header] = array_unique( array_merge( $headers[$header], $options ) );
 313                                         }
 314                                 }
 315                         }
 316                         $this->varyHeaders = $headers;
 317                 }
 318                 return $this->varyHeaders;
 319         }
 320
 321         public function getVaryCookies() {
 322                 // @codeCoverageIgnoreStart
 323                 if ( defined( 'MW_NO_SESSION' ) && MW_NO_SESSION !== 'warn' ) {
 324                         return [];
 325                 }
 326                 // @codeCoverageIgnoreEnd
 327                 if ( $this->varyCookies === null ) {
 328                         $cookies = [];
 329                         foreach ( $this->getProviders() as $provider ) {
 330                                 $cookies = array_merge( $cookies, $provider->getVaryCookies() );
 331                         }
 332                         $this->varyCookies = array_values( array_unique( $cookies ) );
 333                 }
 334                 return $this->varyCookies;
 335         }
 336
 337         /**
 338          * Validate a session ID
 339          * @param string $id
 340          * @return bool
 341          */
 342         public static function validateSessionId( $id ) {
 343                 return is_string( $id ) && preg_match( '/^[a-zA-Z0-9_-]{32,}$/', $id );
 344         }
 345
 346         /**
 347          * @name Internal methods
 348          * @{
 349          */
 350
 351         /**
 352          * Auto-create the given user, if necessary
 353          * @private Don't call this yourself. Let Setup.php do it for you at the right time.
 354          * @note This more properly belongs in AuthManager, but we need it now.
 355          *  When AuthManager comes, this will be deprecated and will pass-through
 356          *  to the corresponding AuthManager method.
 357          * @param User $user User to auto-create
 358          * @return bool Success
 359          */
 360         public static function autoCreateUser( User $user ) {
 361                 global $wgAuth;
 362
 363                 $logger = self::singleton()->logger;
 364
 365                 // Much of this code is based on that in CentralAuth
 366
 367                 // Try the local user from the slave DB
 368                 $localId = User::idFromName( $user->getName() );
 369                 $flags = 0;
 370
 371                 // Fetch the user ID from the master, so that we don't try to create the user
 372                 // when they already exist, due to replication lag
 373                 // @codeCoverageIgnoreStart
 374                 if ( !$localId && wfGetLB()->getReaderIndex() != 0 ) {
 375                         $localId = User::idFromName( $user->getName(), User::READ_LATEST );
 376                         $flags = User::READ_LATEST;
 377                 }
 378                 // @codeCoverageIgnoreEnd
 379
 380                 if ( $localId ) {
 381                         // User exists after all.
 382                         $user->setId( $localId );
 383                         $user->loadFromId( $flags );
 384                         return false;
 385                 }
 386
 387                 // Denied by AuthPlugin? But ignore AuthPlugin itself.
 388                 if ( get_class( $wgAuth ) !== 'AuthPlugin' && !$wgAuth->autoCreate() ) {
 389                         $logger->debug( __METHOD__ . ': denied by AuthPlugin' );
 390                         $user->setId( 0 );
 391                         $user->loadFromId();
 392                         return false;
 393                 }
 394
 395                 // Wiki is read-only?
 396                 if ( wfReadOnly() ) {
 397                         $logger->debug( __METHOD__ . ': denied by wfReadOnly()' );
 398                         $user->setId( 0 );
 399                         $user->loadFromId();
 400                         return false;
 401                 }
 402
 403                 $userName = $user->getName();
 404
 405                 // Check the session, if we tried to create this user already there's
 406                 // no point in retrying.
 407                 $session = self::getGlobalSession();
 408                 $reason = $session->get( 'MWSession::AutoCreateBlacklist' );
 409                 if ( $reason ) {
 410                         $logger->debug( __METHOD__ . ": blacklisted in session ($reason)" );
 411                         $user->setId( 0 );
 412                         $user->loadFromId();
 413                         return false;
 414                 }
 415
 416                 // Is the IP user able to create accounts?
 417                 $anon = new User;
 418                 if ( !$anon->isAllowedAny( 'createaccount', 'autocreateaccount' )
 419                         || $anon->isBlockedFromCreateAccount()
 420                 ) {
 421                         // Blacklist the user to avoid repeated DB queries subsequently
 422                         $logger->debug( __METHOD__ . ': user is blocked from this wiki, blacklisting' );
 423                         $session->set( 'MWSession::AutoCreateBlacklist', 'blocked', 600 );
 424                         $session->persist();
 425                         $user->setId( 0 );
 426                         $user->loadFromId();
 427                         return false;
 428                 }
 429
 430                 // Check for validity of username
 431                 if ( !User::isCreatableName( $userName ) ) {
 432                         $logger->debug( __METHOD__ . ': Invalid username, blacklisting' );
 433                         $session->set( 'MWSession::AutoCreateBlacklist', 'invalid username', 600 );
 434                         $session->persist();
 435                         $user->setId( 0 );
 436                         $user->loadFromId();
 437                         return false;
 438                 }
 439
 440                 // Give other extensions a chance to stop auto creation.
 441                 $user->loadDefaults( $userName );
 442                 $abortMessage = '';
 443                 if ( !\Hooks::run( 'AbortAutoAccount', [ $user, &$abortMessage ] ) ) {
 444                         // In this case we have no way to return the message to the user,
 445                         // but we can log it.
 446                         $logger->debug( __METHOD__ . ": denied by hook: $abortMessage" );
 447                         $session->set( 'MWSession::AutoCreateBlacklist', "hook aborted: $abortMessage", 600 );
 448                         $session->persist();
 449                         $user->setId( 0 );
 450                         $user->loadFromId();
 451                         return false;
 452                 }
 453
 454                 // Make sure the name has not been changed
 455                 if ( $user->getName() !== $userName ) {
 456                         $user->setId( 0 );
 457                         $user->loadFromId();
 458                         throw new \UnexpectedValueException(
 459                                 'AbortAutoAccount hook tried to change the user name'
 460                         );
 461                 }
 462
 463                 // Ignore warnings about master connections/writes...hard to avoid here
 464                 \Profiler::instance()->getTransactionProfiler()->resetExpectations();
 465
 466                 $cache = \ObjectCache::getLocalClusterInstance();
 467                 $backoffKey = wfMemcKey( 'MWSession', 'autocreate-failed', md5( $userName ) );
 468                 if ( $cache->get( $backoffKey ) ) {
 469                         $logger->debug( __METHOD__ . ': denied by prior creation attempt failures' );
 470                         $user->setId( 0 );
 471                         $user->loadFromId();
 472                         return false;
 473                 }
 474
 475                 // Checks passed, create the user...
 476                 $from = isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : 'CLI';
 477                 $logger->info( __METHOD__ . ': creating new user ({username}) - from: {url}',
 478                         [
 479                                 'username' => $userName,
 480                                 'url' => $from,
 481                 ] );
 482
 483                 try {
 484                         // Insert the user into the local DB master
 485                         $status = $user->addToDatabase();
 486                         if ( !$status->isOK() ) {
 487                                 // @codeCoverageIgnoreStart
 488                                 // double-check for a race condition (T70012)
 489                                 $id = User::idFromName( $user->getName(), User::READ_LATEST );
 490                                 if ( $id ) {
 491                                         $logger->info( __METHOD__ . ': tried to autocreate existing user',
 492                                                 [
 493                                                         'username' => $userName,
 494                                                 ] );
 495                                 } else {
 496                                         $logger->error( __METHOD__ . ': failed with message ' . $status->getWikiText(),
 497                                                 [
 498                                                         'username' => $userName,
 499                                                 ] );
 500                                 }
 501                                 $user->setId( $id );
 502                                 $user->loadFromId( User::READ_LATEST );
 503                                 return false;
 504                                 // @codeCoverageIgnoreEnd
 505                         }
 506                 } catch ( \Exception $ex ) {
 507                         // @codeCoverageIgnoreStart
 508                         $logger->error( __METHOD__ . ': failed with exception {exception}', [
 509                                 'exception' => $ex,
 510                                 'username' => $userName,
 511                         ] );
 512                         // Do not keep throwing errors for a while
 513                         $cache->set( $backoffKey, 1, 600 );
 514                         // Bubble up error; which should normally trigger DB rollbacks
 515                         throw $ex;
 516                         // @codeCoverageIgnoreEnd
 517                 }
 518
 519                 # Notify AuthPlugin
 520                 // @codeCoverageIgnoreStart
 521                 $tmpUser = $user;
 522                 $wgAuth->initUser( $tmpUser, true );
 523                 if ( $tmpUser !== $user ) {
 524                         $logger->warning( __METHOD__ . ': ' .
 525                                 get_class( $wgAuth ) . '::initUser() replaced the user object' );
 526                 }
 527                 // @codeCoverageIgnoreEnd
 528
 529                 # Notify hooks (e.g. Newuserlog)
 530                 \Hooks::run( 'AuthPluginAutoCreate', [ $user ] );
 531                 \Hooks::run( 'LocalUserCreated', [ $user, true ] );
 532
 533                 $user->saveSettings();
 534
 535                 # Update user count
 536                 \DeferredUpdates::addUpdate( new \SiteStatsUpdate( 0, 0, 0, 0, 1 ) );
 537
 538                 # Watch user's userpage and talk page
 539                 $user->addWatch( $user->getUserPage(), \WatchedItem::IGNORE_USER_RIGHTS );
 540
 541                 return true;
 542         }
 543
 544         /**
 545          * Prevent future sessions for the user
 546          *
 547          * The intention is that the named account will never again be usable for
 548          * normal login (i.e. there is no way to undo the prevention of access).
 549          *
 550          * @private For use from \\User::newSystemUser only
 551          * @param string $username
 552          */
 553         public function preventSessionsForUser( $username ) {
 554                 $this->preventUsers[$username] = true;
 555
 556                 // Instruct the session providers to kill any other sessions too.
 557                 foreach ( $this->getProviders() as $provider ) {
 558                         $provider->preventSessionsForUser( $username );
 559                 }
 560         }
 561
 562         /**
 563          * Test if a user is prevented
 564          * @private For use from SessionBackend only
 565          * @param string $username
 566          * @return bool
 567          */
 568         public function isUserSessionPrevented( $username ) {
 569                 return !empty( $this->preventUsers[$username] );
 570         }
 571
 572         /**
 573          * Get the available SessionProviders
 574          * @return SessionProvider[]
 575          */
 576         protected function getProviders() {
 577                 if ( $this->sessionProviders === null ) {
 578                         $this->sessionProviders = [];
 579                         foreach ( $this->config->get( 'SessionProviders' ) as $spec ) {
 580                                 $provider = \ObjectFactory::getObjectFromSpec( $spec );
 581                                 $provider->setLogger( $this->logger );
 582                                 $provider->setConfig( $this->config );
 583                                 $provider->setManager( $this );
 584                                 if ( isset( $this->sessionProviders[(string)$provider] ) ) {
 585                                         throw new \UnexpectedValueException( "Duplicate provider name \"$provider\"" );
 586                                 }
 587                                 $this->sessionProviders[(string)$provider] = $provider;
 588                         }
 589                 }
 590                 return $this->sessionProviders;
 591         }
 592
 593         /**
 594          * Get a session provider by name
 595          *
 596          * Generally, this will only be used by internal implementation of some
 597          * special session-providing mechanism. General purpose code, if it needs
 598          * to access a SessionProvider at all, will use Session::getProvider().
 599          *
 600          * @param string $name
 601          * @return SessionProvider|null
 602          */
 603         public function getProvider( $name ) {
 604                 $providers = $this->getProviders();
 605                 return isset( $providers[$name] ) ? $providers[$name] : null;
 606         }
 607
 608         /**
 609          * Save all active sessions on shutdown
 610          * @private For internal use with register_shutdown_function()
 611          */
 612         public function shutdown() {
 613                 if ( $this->allSessionBackends ) {
 614                         $this->logger->debug( 'Saving all sessions on shutdown' );
 615                         if ( session_id() !== '' ) {
 616                                 // @codeCoverageIgnoreStart
 617                                 session_write_close();
 618                         }
 619                         // @codeCoverageIgnoreEnd
 620                         foreach ( $this->allSessionBackends as $backend ) {
 621                                 $backend->save( true );
 622                         }
 623                 }
 624         }
 625
 626         /**
 627          * Fetch the SessionInfo(s) for a request
 628          * @param WebRequest $request
 629          * @return SessionInfo|null
 630          */
 631         private function getSessionInfoForRequest( WebRequest $request ) {
 632                 // Call all providers to fetch "the" session
 633                 $infos = [];
 634                 foreach ( $this->getProviders() as $provider ) {
 635                         $info = $provider->provideSessionInfo( $request );
 636                         if ( !$info ) {
 637                                 continue;
 638                         }
 639                         if ( $info->getProvider() !== $provider ) {
 640                                 throw new \UnexpectedValueException(
 641                                         "$provider returned session info for a different provider: $info"
 642                                 );
 643                         }
 644                         $infos[] = $info;
 645                 }
 646
 647                 // Sort the SessionInfos. Then find the first one that can be
 648                 // successfully loaded, and then all the ones after it with the same
 649                 // priority.
 650                 usort( $infos, 'MediaWiki\\Session\\SessionInfo::compare' );
 651                 $retInfos = [];
 652                 while ( $infos ) {
 653                         $info = array_pop( $infos );
 654                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 655                                 $retInfos[] = $info;
 656                                 while ( $infos ) {
 657                                         $info = array_pop( $infos );
 658                                         if ( SessionInfo::compare( $retInfos[0], $info ) ) {
 659                                                 // We hit a lower priority, stop checking.
 660                                                 break;
 661                                         }
 662                                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 663                                                 // This is going to error out below, but we want to
 664                                                 // provide a complete list.
 665                                                 $retInfos[] = $info;
 666                                         }
 667                                 }
 668                         }
 669                 }
 670
 671                 if ( count( $retInfos ) > 1 ) {
 672                         $ex = new \OverflowException(
 673                                 'Multiple sessions for this request tied for top priority: ' . join( ', ', $retInfos )
 674                         );
 675                         $ex->sessionInfos = $retInfos;
 676                         throw $ex;
 677                 }
 678
 679                 return $retInfos ? $retInfos[0] : null;
 680         }
 681
 682         /**
 683          * Load and verify the session info against the store
 684          *
 685          * @param SessionInfo &$info Will likely be replaced with an updated SessionInfo instance
 686          * @param WebRequest $request
 687          * @return bool Whether the session info matches the stored data (if any)
 688          */
 689         private function loadSessionInfoFromStore( SessionInfo &$info, WebRequest $request ) {
 690                 $key = wfMemcKey( 'MWSession', $info->getId() );
 691                 $blob = $this->store->get( $key );
 692
 693                 $newParams = [];
 694
 695                 if ( $blob !== false ) {
 696                         // Sanity check: blob must be an array, if it's saved at all
 697                         if ( !is_array( $blob ) ) {
 698                                 $this->logger->warning( 'Session "{session}": Bad data', [
 699                                         'session' => $info,
 700                                 ] );
 701                                 $this->store->delete( $key );
 702                                 return false;
 703                         }
 704
 705                         // Sanity check: blob has data and metadata arrays
 706                         if ( !isset( $blob['data'] ) || !is_array( $blob['data'] ) ||
 707                                 !isset( $blob['metadata'] ) || !is_array( $blob['metadata'] )
 708                         ) {
 709                                 $this->logger->warning( 'Session "{session}": Bad data structure', [
 710                                         'session' => $info,
 711                                 ] );
 712                                 $this->store->delete( $key );
 713                                 return false;
 714                         }
 715
 716                         $data = $blob['data'];
 717                         $metadata = $blob['metadata'];
 718
 719                         // Sanity check: metadata must be an array and must contain certain
 720                         // keys, if it's saved at all
 721                         if ( !array_key_exists( 'userId', $metadata ) ||
 722                                 !array_key_exists( 'userName', $metadata ) ||
 723                                 !array_key_exists( 'userToken', $metadata ) ||
 724                                 !array_key_exists( 'provider', $metadata )
 725                         ) {
 726                                 $this->logger->warning( 'Session "{session}": Bad metadata', [
 727                                         'session' => $info,
 728                                 ] );
 729                                 $this->store->delete( $key );
 730                                 return false;
 731                         }
 732
 733                         // First, load the provider from metadata, or validate it against the metadata.
 734                         $provider = $info->getProvider();
 735                         if ( $provider === null ) {
 736                                 $newParams['provider'] = $provider = $this->getProvider( $metadata['provider'] );
 737                                 if ( !$provider ) {
 738                                         $this->logger->warning(
 739                                                 'Session "{session}": Unknown provider ' . $metadata['provider'],
 740                                                 [
 741                                                         'session' => $info,
 742                                                 ]
 743                                         );
 744                                         $this->store->delete( $key );
 745                                         return false;
 746                                 }
 747                         } elseif ( $metadata['provider'] !== (string)$provider ) {
 748                                 $this->logger->warning( 'Session "{session}": Wrong provider ' .
 749                                         $metadata['provider'] . ' !== ' . $provider,
 750                                         [
 751                                                 'session' => $info,
 752                                 ] );
 753                                 return false;
 754                         }
 755
 756                         // Load provider metadata from metadata, or validate it against the metadata
 757                         $providerMetadata = $info->getProviderMetadata();
 758                         if ( isset( $metadata['providerMetadata'] ) ) {
 759                                 if ( $providerMetadata === null ) {
 760                                         $newParams['metadata'] = $metadata['providerMetadata'];
 761                                 } else {
 762                                         try {
 763                                                 $newProviderMetadata = $provider->mergeMetadata(
 764                                                         $metadata['providerMetadata'], $providerMetadata
 765                                                 );
 766                                                 if ( $newProviderMetadata !== $providerMetadata ) {
 767                                                         $newParams['metadata'] = $newProviderMetadata;
 768                                                 }
 769                                         } catch ( MetadataMergeException $ex ) {
 770                                                 $this->logger->warning(
 771                                                         'Session "{session}": Metadata merge failed: {exception}',
 772                                                         [
 773                                                                 'session' => $info,
 774                                                                 'exception' => $ex,
 775                                                         ] + $ex->getContext()
 776                                                 );
 777                                                 return false;
 778                                         }
 779                                 }
 780                         }
 781
 782                         // Next, load the user from metadata, or validate it against the metadata.
 783                         $userInfo = $info->getUserInfo();
 784                         if ( !$userInfo ) {
 785                                 // For loading, id is preferred to name.
 786                                 try {
 787                                         if ( $metadata['userId'] ) {
 788                                                 $userInfo = UserInfo::newFromId( $metadata['userId'] );
 789                                         } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 790                                                 $userInfo = UserInfo::newFromName( $metadata['userName'] );
 791                                         } else {
 792                                                 $userInfo = UserInfo::newAnonymous();
 793                                         }
 794                                 } catch ( \InvalidArgumentException $ex ) {
 795                                         $this->logger->error( 'Session "{session}": {exception}', [
 796                                                 'session' => $info,
 797                                                 'exception' => $ex,
 798                                         ] );
 799                                         return false;
 800                                 }
 801                                 $newParams['userInfo'] = $userInfo;
 802                         } else {
 803                                 // User validation passes if user ID matches, or if there
 804                                 // is no saved ID and the names match.
 805                                 if ( $metadata['userId'] ) {
 806                                         if ( $metadata['userId'] !== $userInfo->getId() ) {
 807                                                 $this->logger->warning(
 808                                                         'Session "{session}": User ID mismatch, {uid_a} !== {uid_b}',
 809                                                         [
 810                                                                 'session' => $info,
 811                                                                 'uid_a' => $metadata['userId'],
 812                                                                 'uid_b' => $userInfo->getId(),
 813                                                 ] );
 814                                                 return false;
 815                                         }
 816
 817                                         // If the user was renamed, probably best to fail here.
 818                                         if ( $metadata['userName'] !== null &&
 819                                                 $userInfo->getName() !== $metadata['userName']
 820                                         ) {
 821                                                 $this->logger->warning(
 822                                                         'Session "{session}": User ID matched but name didn\'t (rename?), {uname_a} !== {uname_b}',
 823                                                         [
 824                                                                 'session' => $info,
 825                                                                 'uname_a' => $metadata['userName'],
 826                                                                 'uname_b' => $userInfo->getName(),
 827                                                 ] );
 828                                                 return false;
 829                                         }
 830
 831                                 } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 832                                         if ( $metadata['userName'] !== $userInfo->getName() ) {
 833                                                 $this->logger->warning(
 834                                                         'Session "{session}": User name mismatch, {uname_a} !== {uname_b}',
 835                                                         [
 836                                                                 'session' => $info,
 837                                                                 'uname_a' => $metadata['userName'],
 838                                                                 'uname_b' => $userInfo->getName(),
 839                                                 ] );
 840                                                 return false;
 841                                         }
 842                                 } elseif ( !$userInfo->isAnon() ) {
 843                                         // Metadata specifies an anonymous user, but the passed-in
 844                                         // user isn't anonymous.
 845                                         $this->logger->warning(
 846                                                 'Session "{session}": Metadata has an anonymous user, but a non-anon user was provided',
 847                                                 [
 848                                                         'session' => $info,
 849                                         ] );
 850                                         return false;
 851                                 }
 852                         }
 853
 854                         // And if we have a token in the metadata, it must match the loaded/provided user.
 855                         if ( $metadata['userToken'] !== null &&
 856                                 $userInfo->getToken() !== $metadata['userToken']
 857                         ) {
 858                                 $this->logger->warning( 'Session "{session}": User token mismatch', [
 859                                         'session' => $info,
 860                                 ] );
 861                                 return false;
 862                         }
 863                         if ( !$userInfo->isVerified() ) {
 864                                 $newParams['userInfo'] = $userInfo->verified();
 865                         }
 866
 867                         if ( !empty( $metadata['remember'] ) && !$info->wasRemembered() ) {
 868                                 $newParams['remembered'] = true;
 869                         }
 870                         if ( !empty( $metadata['forceHTTPS'] ) && !$info->forceHTTPS() ) {
 871                                 $newParams['forceHTTPS'] = true;
 872                         }
 873                         if ( !empty( $metadata['persisted'] ) && !$info->wasPersisted() ) {
 874                                 $newParams['persisted'] = true;
 875                         }
 876
 877                         if ( !$info->isIdSafe() ) {
 878                                 $newParams['idIsSafe'] = true;
 879                         }
 880                 } else {
 881                         // No metadata, so we can't load the provider if one wasn't given.
 882                         if ( $info->getProvider() === null ) {
 883                                 $this->logger->warning(
 884                                         'Session "{session}": Null provider and no metadata',
 885                                         [
 886                                                 'session' => $info,
 887                                 ] );
 888                                 return false;
 889                         }
 890
 891                         // If no user was provided and no metadata, it must be anon.
 892                         if ( !$info->getUserInfo() ) {
 893                                 if ( $info->getProvider()->canChangeUser() ) {
 894                                         $newParams['userInfo'] = UserInfo::newAnonymous();
 895                                 } else {
 896                                         $this->logger->info(
 897                                                 'Session "{session}": No user provided and provider cannot set user',
 898                                                 [
 899                                                         'session' => $info,
 900                                         ] );
 901                                         return false;
 902                                 }
 903                         } elseif ( !$info->getUserInfo()->isVerified() ) {
 904                                 $this->logger->warning(
 905                                         'Session "{session}": Unverified user provided and no metadata to auth it',
 906                                         [
 907                                                 'session' => $info,
 908                                 ] );
 909                                 return false;
 910                         }
 911
 912                         $data = false;
 913                         $metadata = false;
 914
 915                         if ( !$info->getProvider()->persistsSessionId() && !$info->isIdSafe() ) {
 916                                 // The ID doesn't come from the user, so it should be safe
 917                                 // (and if not, nothing we can do about it anyway)
 918                                 $newParams['idIsSafe'] = true;
 919                         }
 920                 }
 921
 922                 // Construct the replacement SessionInfo, if necessary
 923                 if ( $newParams ) {
 924                         $newParams['copyFrom'] = $info;
 925                         $info = new SessionInfo( $info->getPriority(), $newParams );
 926                 }
 927
 928                 // Allow the provider to check the loaded SessionInfo
 929                 $providerMetadata = $info->getProviderMetadata();
 930                 if ( !$info->getProvider()->refreshSessionInfo( $info, $request, $providerMetadata ) ) {
 931                         return false;
 932                 }
 933                 if ( $providerMetadata !== $info->getProviderMetadata() ) {
 934                         $info = new SessionInfo( $info->getPriority(), [
 935                                 'metadata' => $providerMetadata,
 936                                 'copyFrom' => $info,
 937                         ] );
 938                 }
 939
 940                 // Give hooks a chance to abort. Combined with the SessionMetadata
 941                 // hook, this can allow for tying a session to an IP address or the
 942                 // like.
 943                 $reason = 'Hook aborted';
 944                 if ( !\Hooks::run(
 945                         'SessionCheckInfo',
 946                         [ &$reason, $info, $request, $metadata, $data ]
 947                 ) ) {
 948                         $this->logger->warning( 'Session "{session}": ' . $reason, [
 949                                 'session' => $info,
 950                         ] );
 951                         return false;
 952                 }
 953
 954                 return true;
 955         }
 956
 957         /**
 958          * Create a session corresponding to the passed SessionInfo
 959          * @private For use by a SessionProvider that needs to specially create its
 960          *  own session.
 961          * @param SessionInfo $info
 962          * @param WebRequest $request
 963          * @return Session
 964          */
 965         public function getSessionFromInfo( SessionInfo $info, WebRequest $request ) {
 966                 // @codeCoverageIgnoreStart
 967                 if ( defined( 'MW_NO_SESSION' ) ) {
 968                         if ( MW_NO_SESSION === 'warn' ) {
 969                                 // Undocumented safety case for converting existing entry points
 970                                 $this->logger->error( 'Sessions are supposed to be disabled for this entry point' );
 971                         } else {
 972                                 throw new \BadMethodCallException( 'Sessions are disabled for this entry point' );
 973                         }
 974                 }
 975                 // @codeCoverageIgnoreEnd
 976
 977                 $id = $info->getId();
 978
 979                 if ( !isset( $this->allSessionBackends[$id] ) ) {
 980                         if ( !isset( $this->allSessionIds[$id] ) ) {
 981                                 $this->allSessionIds[$id] = new SessionId( $id );
 982                         }
 983                         $backend = new SessionBackend(
 984                                 $this->allSessionIds[$id],
 985                                 $info,
 986                                 $this->store,
 987                                 $this->logger,
 988                                 $this->config->get( 'ObjectCacheSessionExpiry' )
 989                         );
 990                         $this->allSessionBackends[$id] = $backend;
 991                         $delay = $backend->delaySave();
 992                 } else {
 993                         $backend = $this->allSessionBackends[$id];
 994                         $delay = $backend->delaySave();
 995                         if ( $info->wasPersisted() ) {
 996                                 $backend->persist();
 997                         }
 998                         if ( $info->wasRemembered() ) {
 999                                 $backend->setRememberUser( true );
1000                         }
1001                 }
1002
1003                 $request->setSessionId( $backend->getSessionId() );
1004                 $session = $backend->getSession( $request );
1005
1006                 if ( !$info->isIdSafe() ) {
1007                         $session->resetId();
1008                 }
1009
1010                 \ScopedCallback::consume( $delay );
1011                 return $session;
1012         }
1013
1014         /**
1015          * Deregister a SessionBackend
1016          * @private For use from \\MediaWiki\\Session\\SessionBackend only
1017          * @param SessionBackend $backend
1018          */
1019         public function deregisterSessionBackend( SessionBackend $backend ) {
1020                 $id = $backend->getId();
1021                 if ( !isset( $this->allSessionBackends[$id] ) || !isset( $this->allSessionIds[$id] ) ||
1022                         $this->allSessionBackends[$id] !== $backend ||
1023                         $this->allSessionIds[$id] !== $backend->getSessionId()
1024                 ) {
1025                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
1026                 }
1027
1028                 unset( $this->allSessionBackends[$id] );
1029                 // Explicitly do not unset $this->allSessionIds[$id]
1030         }
1031
1032         /**
1033          * Change a SessionBackend's ID
1034          * @private For use from \\MediaWiki\\Session\\SessionBackend only
1035          * @param SessionBackend $backend
1036          */
1037         public function changeBackendId( SessionBackend $backend ) {
1038                 $sessionId = $backend->getSessionId();
1039                 $oldId = (string)$sessionId;
1040                 if ( !isset( $this->allSessionBackends[$oldId] ) || !isset( $this->allSessionIds[$oldId] ) ||
1041                         $this->allSessionBackends[$oldId] !== $backend ||
1042                         $this->allSessionIds[$oldId] !== $sessionId
1043                 ) {
1044                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
1045                 }
1046
1047                 $newId = $this->generateSessionId();
1048
1049                 unset( $this->allSessionBackends[$oldId], $this->allSessionIds[$oldId] );
1050                 $sessionId->setId( $newId );
1051                 $this->allSessionBackends[$newId] = $backend;
1052                 $this->allSessionIds[$newId] = $sessionId;
1053         }
1054
1055         /**
1056          * Generate a new random session ID
1057          * @return string
1058          */
1059         public function generateSessionId() {
1060                 do {
1061                         $id = wfBaseConvert( \MWCryptRand::generateHex( 40 ), 16, 32, 32 );
1062                         $key = wfMemcKey( 'MWSession', $id );
1063                 } while ( isset( $this->allSessionIds[$id] ) || is_array( $this->store->get( $key ) ) );
1064                 return $id;
1065         }
1066
1067         /**
1068          * Call setters on a PHPSessionHandler
1069          * @private Use PhpSessionHandler::install()
1070          * @param PHPSessionHandler $handler
1071          */
1072         public function setupPHPSessionHandler( PHPSessionHandler $handler ) {
1073                 $handler->setManager( $this, $this->store, $this->logger );
1074         }
1075
1076         /**
1077          * Reset the internal caching for unit testing
1078          */
1079         public static function resetCache() {
1080                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
1081                         // @codeCoverageIgnoreStart
1082                         throw new MWException( __METHOD__ . ' may only be called from unit tests!' );
1083                         // @codeCoverageIgnoreEnd
1084                 }
1085
1086                 self::$globalSession = null;
1087                 self::$globalSessionRequest = null;
1088         }
1089
1090         /**@}*/
1091
1092 }