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 MWException;
  27 use Psr\Log\LoggerInterface;
  28 use BagOStuff;
  29 use CachedBagOStuff;
  30 use Config;
  31 use FauxRequest;
  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 CachedBagOStuff|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 = [];
  71
  72         /** @var SessionId[] */
  73         private $allSessionIds = [];
  74
  75         /** @var string[] */
  76         private $preventUsers = [];
  77
  78         /**
  79          * Get the global SessionManager
  80          * @return SessionManagerInterface
  81          *  (really a SessionManager, but this is to make IDEs less confused)
  82          */
  83         public static function singleton() {
  84                 if ( self::$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 = [] ) {
 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                         $store = $options['store'];
 169                 } else {
 170                         $store = \ObjectCache::getInstance( $this->config->get( 'SessionCacheType' ) );
 171                 }
 172                 $this->store = $store instanceof CachedBagOStuff ? $store : new CachedBagOStuff( $store );
 173
 174                 register_shutdown_function( [ $this, 'shutdown' ] );
 175         }
 176
 177         public function setLogger( LoggerInterface $logger ) {
 178                 $this->logger = $logger;
 179         }
 180
 181         public function getSessionForRequest( WebRequest $request ) {
 182                 $info = $this->getSessionInfoForRequest( $request );
 183
 184                 if ( !$info ) {
 185                         $session = $this->getEmptySession( $request );
 186                 } else {
 187                         $session = $this->getSessionFromInfo( $info, $request );
 188                 }
 189                 return $session;
 190         }
 191
 192         public function getSessionById( $id, $create = false, WebRequest $request = null ) {
 193                 if ( !self::validateSessionId( $id ) ) {
 194                         throw new \InvalidArgumentException( 'Invalid session ID' );
 195                 }
 196                 if ( !$request ) {
 197                         $request = new FauxRequest;
 198                 }
 199
 200                 $session = null;
 201                 $info = new SessionInfo( SessionInfo::MIN_PRIORITY, [ 'id' => $id, 'idIsSafe' => true ] );
 202
 203                 // If we already have the backend loaded, use it directly
 204                 if ( isset( $this->allSessionBackends[$id] ) ) {
 205                         return $this->getSessionFromInfo( $info, $request );
 206                 }
 207
 208                 // Test if the session is in storage, and if so try to load it.
 209                 $key = wfMemcKey( 'MWSession', $id );
 210                 if ( is_array( $this->store->get( $key ) ) ) {
 211                         $create = false; // If loading fails, don't bother creating because it probably will fail too.
 212                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 213                                 $session = $this->getSessionFromInfo( $info, $request );
 214                         }
 215                 }
 216
 217                 if ( $create && $session === null ) {
 218                         $ex = null;
 219                         try {
 220                                 $session = $this->getEmptySessionInternal( $request, $id );
 221                         } catch ( \Exception $ex ) {
 222                                 $this->logger->error( 'Failed to create empty session: {exception}',
 223                                         [
 224                                                 'method' => __METHOD__,
 225                                                 'exception' => $ex,
 226                                 ] );
 227                                 $session = null;
 228                         }
 229                 }
 230
 231                 return $session;
 232         }
 233
 234         public function getEmptySession( WebRequest $request = null ) {
 235                 return $this->getEmptySessionInternal( $request );
 236         }
 237
 238         /**
 239          * @see SessionManagerInterface::getEmptySession
 240          * @param WebRequest|null $request
 241          * @param string|null $id ID to force on the new session
 242          * @return Session
 243          */
 244         private function getEmptySessionInternal( WebRequest $request = null, $id = null ) {
 245                 if ( $id !== null ) {
 246                         if ( !self::validateSessionId( $id ) ) {
 247                                 throw new \InvalidArgumentException( 'Invalid session ID' );
 248                         }
 249
 250                         $key = wfMemcKey( 'MWSession', $id );
 251                         if ( is_array( $this->store->get( $key ) ) ) {
 252                                 throw new \InvalidArgumentException( 'Session ID already exists' );
 253                         }
 254                 }
 255                 if ( !$request ) {
 256                         $request = new FauxRequest;
 257                 }
 258
 259                 $infos = [];
 260                 foreach ( $this->getProviders() as $provider ) {
 261                         $info = $provider->newSessionInfo( $id );
 262                         if ( !$info ) {
 263                                 continue;
 264                         }
 265                         if ( $info->getProvider() !== $provider ) {
 266                                 throw new \UnexpectedValueException(
 267                                         "$provider returned an empty session info for a different provider: $info"
 268                                 );
 269                         }
 270                         if ( $id !== null && $info->getId() !== $id ) {
 271                                 throw new \UnexpectedValueException(
 272                                         "$provider returned empty session info with a wrong id: " .
 273                                                 $info->getId() . ' != ' . $id
 274                                 );
 275                         }
 276                         if ( !$info->isIdSafe() ) {
 277                                 throw new \UnexpectedValueException(
 278                                         "$provider returned empty session info with id flagged unsafe"
 279                                 );
 280                         }
 281                         $compare = $infos ? SessionInfo::compare( $infos[0], $info ) : -1;
 282                         if ( $compare > 0 ) {
 283                                 continue;
 284                         }
 285                         if ( $compare === 0 ) {
 286                                 $infos[] = $info;
 287                         } else {
 288                                 $infos = [ $info ];
 289                         }
 290                 }
 291
 292                 // Make sure there's exactly one
 293                 if ( count( $infos ) > 1 ) {
 294                         throw new \UnexpectedValueException(
 295                                 'Multiple empty sessions tied for top priority: ' . implode( ', ', $infos )
 296                         );
 297                 } elseif ( count( $infos ) < 1 ) {
 298                         throw new \UnexpectedValueException( 'No provider could provide an empty session!' );
 299                 }
 300
 301                 return $this->getSessionFromInfo( $infos[0], $request );
 302         }
 303
 304         public function invalidateSessionsForUser( User $user ) {
 305                 global $wgAuth;
 306
 307                 $user->setToken();
 308                 $user->saveSettings();
 309
 310                 $wgAuth->getUserInstance( $user )->resetAuthToken();
 311
 312                 foreach ( $this->getProviders() as $provider ) {
 313                         $provider->invalidateSessionsForUser( $user );
 314                 }
 315         }
 316
 317         public function getVaryHeaders() {
 318                 // @codeCoverageIgnoreStart
 319                 if ( defined( 'MW_NO_SESSION' ) && MW_NO_SESSION !== 'warn' ) {
 320                         return [];
 321                 }
 322                 // @codeCoverageIgnoreEnd
 323                 if ( $this->varyHeaders === null ) {
 324                         $headers = [];
 325                         foreach ( $this->getProviders() as $provider ) {
 326                                 foreach ( $provider->getVaryHeaders() as $header => $options ) {
 327                                         if ( !isset( $headers[$header] ) ) {
 328                                                 $headers[$header] = [];
 329                                         }
 330                                         if ( is_array( $options ) ) {
 331                                                 $headers[$header] = array_unique( array_merge( $headers[$header], $options ) );
 332                                         }
 333                                 }
 334                         }
 335                         $this->varyHeaders = $headers;
 336                 }
 337                 return $this->varyHeaders;
 338         }
 339
 340         public function getVaryCookies() {
 341                 // @codeCoverageIgnoreStart
 342                 if ( defined( 'MW_NO_SESSION' ) && MW_NO_SESSION !== 'warn' ) {
 343                         return [];
 344                 }
 345                 // @codeCoverageIgnoreEnd
 346                 if ( $this->varyCookies === null ) {
 347                         $cookies = [];
 348                         foreach ( $this->getProviders() as $provider ) {
 349                                 $cookies = array_merge( $cookies, $provider->getVaryCookies() );
 350                         }
 351                         $this->varyCookies = array_values( array_unique( $cookies ) );
 352                 }
 353                 return $this->varyCookies;
 354         }
 355
 356         /**
 357          * Validate a session ID
 358          * @param string $id
 359          * @return bool
 360          */
 361         public static function validateSessionId( $id ) {
 362                 return is_string( $id ) && preg_match( '/^[a-zA-Z0-9_-]{32,}$/', $id );
 363         }
 364
 365         /**
 366          * @name Internal methods
 367          * @{
 368          */
 369
 370         /**
 371          * Auto-create the given user, if necessary
 372          * @private Don't call this yourself. Let Setup.php do it for you at the right time.
 373          * @note This more properly belongs in AuthManager, but we need it now.
 374          *  When AuthManager comes, this will be deprecated and will pass-through
 375          *  to the corresponding AuthManager method.
 376          * @param User $user User to auto-create
 377          * @return bool Success
 378          */
 379         public static function autoCreateUser( User $user ) {
 380                 global $wgAuth;
 381
 382                 $logger = self::singleton()->logger;
 383
 384                 // Much of this code is based on that in CentralAuth
 385
 386                 // Try the local user from the slave DB
 387                 $localId = User::idFromName( $user->getName() );
 388                 $flags = 0;
 389
 390                 // Fetch the user ID from the master, so that we don't try to create the user
 391                 // when they already exist, due to replication lag
 392                 // @codeCoverageIgnoreStart
 393                 if ( !$localId && wfGetLB()->getReaderIndex() != 0 ) {
 394                         $localId = User::idFromName( $user->getName(), User::READ_LATEST );
 395                         $flags = User::READ_LATEST;
 396                 }
 397                 // @codeCoverageIgnoreEnd
 398
 399                 if ( $localId ) {
 400                         // User exists after all.
 401                         $user->setId( $localId );
 402                         $user->loadFromId( $flags );
 403                         return false;
 404                 }
 405
 406                 // Denied by AuthPlugin? But ignore AuthPlugin itself.
 407                 if ( get_class( $wgAuth ) !== 'AuthPlugin' && !$wgAuth->autoCreate() ) {
 408                         $logger->debug( __METHOD__ . ': denied by AuthPlugin' );
 409                         $user->setId( 0 );
 410                         $user->loadFromId();
 411                         return false;
 412                 }
 413
 414                 // Wiki is read-only?
 415                 if ( wfReadOnly() ) {
 416                         $logger->debug( __METHOD__ . ': denied by wfReadOnly()' );
 417                         $user->setId( 0 );
 418                         $user->loadFromId();
 419                         return false;
 420                 }
 421
 422                 $userName = $user->getName();
 423
 424                 // Check the session, if we tried to create this user already there's
 425                 // no point in retrying.
 426                 $session = self::getGlobalSession();
 427                 $reason = $session->get( 'MWSession::AutoCreateBlacklist' );
 428                 if ( $reason ) {
 429                         $logger->debug( __METHOD__ . ": blacklisted in session ($reason)" );
 430                         $user->setId( 0 );
 431                         $user->loadFromId();
 432                         return false;
 433                 }
 434
 435                 // Is the IP user able to create accounts?
 436                 $anon = new User;
 437                 if ( !$anon->isAllowedAny( 'createaccount', 'autocreateaccount' )
 438                         || $anon->isBlockedFromCreateAccount()
 439                 ) {
 440                         // Blacklist the user to avoid repeated DB queries subsequently
 441                         $logger->debug( __METHOD__ . ': user is blocked from this wiki, blacklisting' );
 442                         $session->set( 'MWSession::AutoCreateBlacklist', 'blocked', 600 );
 443                         $session->persist();
 444                         $user->setId( 0 );
 445                         $user->loadFromId();
 446                         return false;
 447                 }
 448
 449                 // Check for validity of username
 450                 if ( !User::isCreatableName( $userName ) ) {
 451                         $logger->debug( __METHOD__ . ': Invalid username, blacklisting' );
 452                         $session->set( 'MWSession::AutoCreateBlacklist', 'invalid username', 600 );
 453                         $session->persist();
 454                         $user->setId( 0 );
 455                         $user->loadFromId();
 456                         return false;
 457                 }
 458
 459                 // Give other extensions a chance to stop auto creation.
 460                 $user->loadDefaults( $userName );
 461                 $abortMessage = '';
 462                 if ( !\Hooks::run( 'AbortAutoAccount', [ $user, &$abortMessage ] ) ) {
 463                         // In this case we have no way to return the message to the user,
 464                         // but we can log it.
 465                         $logger->debug( __METHOD__ . ": denied by hook: $abortMessage" );
 466                         $session->set( 'MWSession::AutoCreateBlacklist', "hook aborted: $abortMessage", 600 );
 467                         $session->persist();
 468                         $user->setId( 0 );
 469                         $user->loadFromId();
 470                         return false;
 471                 }
 472
 473                 // Make sure the name has not been changed
 474                 if ( $user->getName() !== $userName ) {
 475                         $user->setId( 0 );
 476                         $user->loadFromId();
 477                         throw new \UnexpectedValueException(
 478                                 'AbortAutoAccount hook tried to change the user name'
 479                         );
 480                 }
 481
 482                 // Ignore warnings about master connections/writes...hard to avoid here
 483                 \Profiler::instance()->getTransactionProfiler()->resetExpectations();
 484
 485                 $cache = \ObjectCache::getLocalClusterInstance();
 486                 $backoffKey = wfMemcKey( 'MWSession', 'autocreate-failed', md5( $userName ) );
 487                 if ( $cache->get( $backoffKey ) ) {
 488                         $logger->debug( __METHOD__ . ': denied by prior creation attempt failures' );
 489                         $user->setId( 0 );
 490                         $user->loadFromId();
 491                         return false;
 492                 }
 493
 494                 // Checks passed, create the user...
 495                 $from = isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : 'CLI';
 496                 $logger->info( __METHOD__ . ': creating new user ({username}) - from: {url}',
 497                         [
 498                                 'username' => $userName,
 499                                 'url' => $from,
 500                 ] );
 501
 502                 try {
 503                         // Insert the user into the local DB master
 504                         $status = $user->addToDatabase();
 505                         if ( !$status->isOK() ) {
 506                                 // @codeCoverageIgnoreStart
 507                                 // double-check for a race condition (T70012)
 508                                 $id = User::idFromName( $user->getName(), User::READ_LATEST );
 509                                 if ( $id ) {
 510                                         $logger->info( __METHOD__ . ': tried to autocreate existing user',
 511                                                 [
 512                                                         'username' => $userName,
 513                                                 ] );
 514                                 } else {
 515                                         $logger->error(
 516                                                 __METHOD__ . ': failed with message ' . $status->getWikiText( false, false, 'en' ),
 517                                                 [
 518                                                         'username' => $userName,
 519                                                 ]
 520                                         );
 521                                 }
 522                                 $user->setId( $id );
 523                                 $user->loadFromId( User::READ_LATEST );
 524                                 return false;
 525                                 // @codeCoverageIgnoreEnd
 526                         }
 527                 } catch ( \Exception $ex ) {
 528                         // @codeCoverageIgnoreStart
 529                         $logger->error( __METHOD__ . ': failed with exception {exception}', [
 530                                 'exception' => $ex,
 531                                 'username' => $userName,
 532                         ] );
 533                         // Do not keep throwing errors for a while
 534                         $cache->set( $backoffKey, 1, 600 );
 535                         // Bubble up error; which should normally trigger DB rollbacks
 536                         throw $ex;
 537                         // @codeCoverageIgnoreEnd
 538                 }
 539
 540                 # Notify AuthPlugin
 541                 // @codeCoverageIgnoreStart
 542                 $tmpUser = $user;
 543                 $wgAuth->initUser( $tmpUser, true );
 544                 if ( $tmpUser !== $user ) {
 545                         $logger->warning( __METHOD__ . ': ' .
 546                                 get_class( $wgAuth ) . '::initUser() replaced the user object' );
 547                 }
 548                 // @codeCoverageIgnoreEnd
 549
 550                 # Notify hooks (e.g. Newuserlog)
 551                 \Hooks::run( 'AuthPluginAutoCreate', [ $user ] );
 552                 \Hooks::run( 'LocalUserCreated', [ $user, true ] );
 553
 554                 $user->saveSettings();
 555
 556                 # Update user count
 557                 \DeferredUpdates::addUpdate( new \SiteStatsUpdate( 0, 0, 0, 0, 1 ) );
 558
 559                 # Watch user's userpage and talk page
 560                 $user->addWatch( $user->getUserPage(), User::IGNORE_USER_RIGHTS );
 561
 562                 return true;
 563         }
 564
 565         /**
 566          * Prevent future sessions for the user
 567          *
 568          * The intention is that the named account will never again be usable for
 569          * normal login (i.e. there is no way to undo the prevention of access).
 570          *
 571          * @private For use from \User::newSystemUser only
 572          * @param string $username
 573          */
 574         public function preventSessionsForUser( $username ) {
 575                 $this->preventUsers[$username] = true;
 576
 577                 // Instruct the session providers to kill any other sessions too.
 578                 foreach ( $this->getProviders() as $provider ) {
 579                         $provider->preventSessionsForUser( $username );
 580                 }
 581         }
 582
 583         /**
 584          * Test if a user is prevented
 585          * @private For use from SessionBackend only
 586          * @param string $username
 587          * @return bool
 588          */
 589         public function isUserSessionPrevented( $username ) {
 590                 return !empty( $this->preventUsers[$username] );
 591         }
 592
 593         /**
 594          * Get the available SessionProviders
 595          * @return SessionProvider[]
 596          */
 597         protected function getProviders() {
 598                 if ( $this->sessionProviders === null ) {
 599                         $this->sessionProviders = [];
 600                         foreach ( $this->config->get( 'SessionProviders' ) as $spec ) {
 601                                 $provider = \ObjectFactory::getObjectFromSpec( $spec );
 602                                 $provider->setLogger( $this->logger );
 603                                 $provider->setConfig( $this->config );
 604                                 $provider->setManager( $this );
 605                                 if ( isset( $this->sessionProviders[(string)$provider] ) ) {
 606                                         throw new \UnexpectedValueException( "Duplicate provider name \"$provider\"" );
 607                                 }
 608                                 $this->sessionProviders[(string)$provider] = $provider;
 609                         }
 610                 }
 611                 return $this->sessionProviders;
 612         }
 613
 614         /**
 615          * Get a session provider by name
 616          *
 617          * Generally, this will only be used by internal implementation of some
 618          * special session-providing mechanism. General purpose code, if it needs
 619          * to access a SessionProvider at all, will use Session::getProvider().
 620          *
 621          * @param string $name
 622          * @return SessionProvider|null
 623          */
 624         public function getProvider( $name ) {
 625                 $providers = $this->getProviders();
 626                 return isset( $providers[$name] ) ? $providers[$name] : null;
 627         }
 628
 629         /**
 630          * Save all active sessions on shutdown
 631          * @private For internal use with register_shutdown_function()
 632          */
 633         public function shutdown() {
 634                 if ( $this->allSessionBackends ) {
 635                         $this->logger->debug( 'Saving all sessions on shutdown' );
 636                         if ( session_id() !== '' ) {
 637                                 // @codeCoverageIgnoreStart
 638                                 session_write_close();
 639                         }
 640                         // @codeCoverageIgnoreEnd
 641                         foreach ( $this->allSessionBackends as $backend ) {
 642                                 $backend->shutdown();
 643                         }
 644                 }
 645         }
 646
 647         /**
 648          * Fetch the SessionInfo(s) for a request
 649          * @param WebRequest $request
 650          * @return SessionInfo|null
 651          */
 652         private function getSessionInfoForRequest( WebRequest $request ) {
 653                 // Call all providers to fetch "the" session
 654                 $infos = [];
 655                 foreach ( $this->getProviders() as $provider ) {
 656                         $info = $provider->provideSessionInfo( $request );
 657                         if ( !$info ) {
 658                                 continue;
 659                         }
 660                         if ( $info->getProvider() !== $provider ) {
 661                                 throw new \UnexpectedValueException(
 662                                         "$provider returned session info for a different provider: $info"
 663                                 );
 664                         }
 665                         $infos[] = $info;
 666                 }
 667
 668                 // Sort the SessionInfos. Then find the first one that can be
 669                 // successfully loaded, and then all the ones after it with the same
 670                 // priority.
 671                 usort( $infos, 'MediaWiki\\Session\\SessionInfo::compare' );
 672                 $retInfos = [];
 673                 while ( $infos ) {
 674                         $info = array_pop( $infos );
 675                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 676                                 $retInfos[] = $info;
 677                                 while ( $infos ) {
 678                                         $info = array_pop( $infos );
 679                                         if ( SessionInfo::compare( $retInfos[0], $info ) ) {
 680                                                 // We hit a lower priority, stop checking.
 681                                                 break;
 682                                         }
 683                                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 684                                                 // This is going to error out below, but we want to
 685                                                 // provide a complete list.
 686                                                 $retInfos[] = $info;
 687                                         } else {
 688                                                 // Session load failed, so unpersist it from this request
 689                                                 $info->getProvider()->unpersistSession( $request );
 690                                         }
 691                                 }
 692                         } else {
 693                                 // Session load failed, so unpersist it from this request
 694                                 $info->getProvider()->unpersistSession( $request );
 695                         }
 696                 }
 697
 698                 if ( count( $retInfos ) > 1 ) {
 699                         $ex = new \OverflowException(
 700                                 'Multiple sessions for this request tied for top priority: ' . implode( ', ', $retInfos )
 701                         );
 702                         $ex->sessionInfos = $retInfos;
 703                         throw $ex;
 704                 }
 705
 706                 return $retInfos ? $retInfos[0] : null;
 707         }
 708
 709         /**
 710          * Load and verify the session info against the store
 711          *
 712          * @param SessionInfo &$info Will likely be replaced with an updated SessionInfo instance
 713          * @param WebRequest $request
 714          * @return bool Whether the session info matches the stored data (if any)
 715          */
 716         private function loadSessionInfoFromStore( SessionInfo &$info, WebRequest $request ) {
 717                 $key = wfMemcKey( 'MWSession', $info->getId() );
 718                 $blob = $this->store->get( $key );
 719
 720                 // If we got data from the store and the SessionInfo says to force use,
 721                 // "fail" means to delete the data from the store and retry. Otherwise,
 722                 // "fail" is just return false.
 723                 if ( $info->forceUse() && $blob !== false ) {
 724                         $failHandler = function () use ( $key, &$info, $request ) {
 725                                 $this->store->delete( $key );
 726                                 return $this->loadSessionInfoFromStore( $info, $request );
 727                         };
 728                 } else {
 729                         $failHandler = function () {
 730                                 return false;
 731                         };
 732                 }
 733
 734                 $newParams = [];
 735
 736                 if ( $blob !== false ) {
 737                         // Sanity check: blob must be an array, if it's saved at all
 738                         if ( !is_array( $blob ) ) {
 739                                 $this->logger->warning( 'Session "{session}": Bad data', [
 740                                         'session' => $info,
 741                                 ] );
 742                                 $this->store->delete( $key );
 743                                 return $failHandler();
 744                         }
 745
 746                         // Sanity check: blob has data and metadata arrays
 747                         if ( !isset( $blob['data'] ) || !is_array( $blob['data'] ) ||
 748                                 !isset( $blob['metadata'] ) || !is_array( $blob['metadata'] )
 749                         ) {
 750                                 $this->logger->warning( 'Session "{session}": Bad data structure', [
 751                                         'session' => $info,
 752                                 ] );
 753                                 $this->store->delete( $key );
 754                                 return $failHandler();
 755                         }
 756
 757                         $data = $blob['data'];
 758                         $metadata = $blob['metadata'];
 759
 760                         // Sanity check: metadata must be an array and must contain certain
 761                         // keys, if it's saved at all
 762                         if ( !array_key_exists( 'userId', $metadata ) ||
 763                                 !array_key_exists( 'userName', $metadata ) ||
 764                                 !array_key_exists( 'userToken', $metadata ) ||
 765                                 !array_key_exists( 'provider', $metadata )
 766                         ) {
 767                                 $this->logger->warning( 'Session "{session}": Bad metadata', [
 768                                         'session' => $info,
 769                                 ] );
 770                                 $this->store->delete( $key );
 771                                 return $failHandler();
 772                         }
 773
 774                         // First, load the provider from metadata, or validate it against the metadata.
 775                         $provider = $info->getProvider();
 776                         if ( $provider === null ) {
 777                                 $newParams['provider'] = $provider = $this->getProvider( $metadata['provider'] );
 778                                 if ( !$provider ) {
 779                                         $this->logger->warning(
 780                                                 'Session "{session}": Unknown provider ' . $metadata['provider'],
 781                                                 [
 782                                                         'session' => $info,
 783                                                 ]
 784                                         );
 785                                         $this->store->delete( $key );
 786                                         return $failHandler();
 787                                 }
 788                         } elseif ( $metadata['provider'] !== (string)$provider ) {
 789                                 $this->logger->warning( 'Session "{session}": Wrong provider ' .
 790                                         $metadata['provider'] . ' !== ' . $provider,
 791                                         [
 792                                                 'session' => $info,
 793                                 ] );
 794                                 return $failHandler();
 795                         }
 796
 797                         // Load provider metadata from metadata, or validate it against the metadata
 798                         $providerMetadata = $info->getProviderMetadata();
 799                         if ( isset( $metadata['providerMetadata'] ) ) {
 800                                 if ( $providerMetadata === null ) {
 801                                         $newParams['metadata'] = $metadata['providerMetadata'];
 802                                 } else {
 803                                         try {
 804                                                 $newProviderMetadata = $provider->mergeMetadata(
 805                                                         $metadata['providerMetadata'], $providerMetadata
 806                                                 );
 807                                                 if ( $newProviderMetadata !== $providerMetadata ) {
 808                                                         $newParams['metadata'] = $newProviderMetadata;
 809                                                 }
 810                                         } catch ( MetadataMergeException $ex ) {
 811                                                 $this->logger->warning(
 812                                                         'Session "{session}": Metadata merge failed: {exception}',
 813                                                         [
 814                                                                 'session' => $info,
 815                                                                 'exception' => $ex,
 816                                                         ] + $ex->getContext()
 817                                                 );
 818                                                 return $failHandler();
 819                                         }
 820                                 }
 821                         }
 822
 823                         // Next, load the user from metadata, or validate it against the metadata.
 824                         $userInfo = $info->getUserInfo();
 825                         if ( !$userInfo ) {
 826                                 // For loading, id is preferred to name.
 827                                 try {
 828                                         if ( $metadata['userId'] ) {
 829                                                 $userInfo = UserInfo::newFromId( $metadata['userId'] );
 830                                         } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 831                                                 $userInfo = UserInfo::newFromName( $metadata['userName'] );
 832                                         } else {
 833                                                 $userInfo = UserInfo::newAnonymous();
 834                                         }
 835                                 } catch ( \InvalidArgumentException $ex ) {
 836                                         $this->logger->error( 'Session "{session}": {exception}', [
 837                                                 'session' => $info,
 838                                                 'exception' => $ex,
 839                                         ] );
 840                                         return $failHandler();
 841                                 }
 842                                 $newParams['userInfo'] = $userInfo;
 843                         } else {
 844                                 // User validation passes if user ID matches, or if there
 845                                 // is no saved ID and the names match.
 846                                 if ( $metadata['userId'] ) {
 847                                         if ( $metadata['userId'] !== $userInfo->getId() ) {
 848                                                 $this->logger->warning(
 849                                                         'Session "{session}": User ID mismatch, {uid_a} !== {uid_b}',
 850                                                         [
 851                                                                 'session' => $info,
 852                                                                 'uid_a' => $metadata['userId'],
 853                                                                 'uid_b' => $userInfo->getId(),
 854                                                 ] );
 855                                                 return $failHandler();
 856                                         }
 857
 858                                         // If the user was renamed, probably best to fail here.
 859                                         if ( $metadata['userName'] !== null &&
 860                                                 $userInfo->getName() !== $metadata['userName']
 861                                         ) {
 862                                                 $this->logger->warning(
 863                                                         'Session "{session}": User ID matched but name didn\'t (rename?), {uname_a} !== {uname_b}',
 864                                                         [
 865                                                                 'session' => $info,
 866                                                                 'uname_a' => $metadata['userName'],
 867                                                                 'uname_b' => $userInfo->getName(),
 868                                                 ] );
 869                                                 return $failHandler();
 870                                         }
 871
 872                                 } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 873                                         if ( $metadata['userName'] !== $userInfo->getName() ) {
 874                                                 $this->logger->warning(
 875                                                         'Session "{session}": User name mismatch, {uname_a} !== {uname_b}',
 876                                                         [
 877                                                                 'session' => $info,
 878                                                                 'uname_a' => $metadata['userName'],
 879                                                                 'uname_b' => $userInfo->getName(),
 880                                                 ] );
 881                                                 return $failHandler();
 882                                         }
 883                                 } elseif ( !$userInfo->isAnon() ) {
 884                                         // Metadata specifies an anonymous user, but the passed-in
 885                                         // user isn't anonymous.
 886                                         $this->logger->warning(
 887                                                 'Session "{session}": Metadata has an anonymous user, but a non-anon user was provided',
 888                                                 [
 889                                                         'session' => $info,
 890                                         ] );
 891                                         return $failHandler();
 892                                 }
 893                         }
 894
 895                         // And if we have a token in the metadata, it must match the loaded/provided user.
 896                         if ( $metadata['userToken'] !== null &&
 897                                 $userInfo->getToken() !== $metadata['userToken']
 898                         ) {
 899                                 $this->logger->warning( 'Session "{session}": User token mismatch', [
 900                                         'session' => $info,
 901                                 ] );
 902                                 return $failHandler();
 903                         }
 904                         if ( !$userInfo->isVerified() ) {
 905                                 $newParams['userInfo'] = $userInfo->verified();
 906                         }
 907
 908                         if ( !empty( $metadata['remember'] ) && !$info->wasRemembered() ) {
 909                                 $newParams['remembered'] = true;
 910                         }
 911                         if ( !empty( $metadata['forceHTTPS'] ) && !$info->forceHTTPS() ) {
 912                                 $newParams['forceHTTPS'] = true;
 913                         }
 914                         if ( !empty( $metadata['persisted'] ) && !$info->wasPersisted() ) {
 915                                 $newParams['persisted'] = true;
 916                         }
 917
 918                         if ( !$info->isIdSafe() ) {
 919                                 $newParams['idIsSafe'] = true;
 920                         }
 921                 } else {
 922                         // No metadata, so we can't load the provider if one wasn't given.
 923                         if ( $info->getProvider() === null ) {
 924                                 $this->logger->warning(
 925                                         'Session "{session}": Null provider and no metadata',
 926                                         [
 927                                                 'session' => $info,
 928                                 ] );
 929                                 return $failHandler();
 930                         }
 931
 932                         // If no user was provided and no metadata, it must be anon.
 933                         if ( !$info->getUserInfo() ) {
 934                                 if ( $info->getProvider()->canChangeUser() ) {
 935                                         $newParams['userInfo'] = UserInfo::newAnonymous();
 936                                 } else {
 937                                         $this->logger->info(
 938                                                 'Session "{session}": No user provided and provider cannot set user',
 939                                                 [
 940                                                         'session' => $info,
 941                                         ] );
 942                                         return $failHandler();
 943                                 }
 944                         } elseif ( !$info->getUserInfo()->isVerified() ) {
 945                                 $this->logger->warning(
 946                                         'Session "{session}": Unverified user provided and no metadata to auth it',
 947                                         [
 948                                                 'session' => $info,
 949                                 ] );
 950                                 return $failHandler();
 951                         }
 952
 953                         $data = false;
 954                         $metadata = false;
 955
 956                         if ( !$info->getProvider()->persistsSessionId() && !$info->isIdSafe() ) {
 957                                 // The ID doesn't come from the user, so it should be safe
 958                                 // (and if not, nothing we can do about it anyway)
 959                                 $newParams['idIsSafe'] = true;
 960                         }
 961                 }
 962
 963                 // Construct the replacement SessionInfo, if necessary
 964                 if ( $newParams ) {
 965                         $newParams['copyFrom'] = $info;
 966                         $info = new SessionInfo( $info->getPriority(), $newParams );
 967                 }
 968
 969                 // Allow the provider to check the loaded SessionInfo
 970                 $providerMetadata = $info->getProviderMetadata();
 971                 if ( !$info->getProvider()->refreshSessionInfo( $info, $request, $providerMetadata ) ) {
 972                         return $failHandler();
 973                 }
 974                 if ( $providerMetadata !== $info->getProviderMetadata() ) {
 975                         $info = new SessionInfo( $info->getPriority(), [
 976                                 'metadata' => $providerMetadata,
 977                                 'copyFrom' => $info,
 978                         ] );
 979                 }
 980
 981                 // Give hooks a chance to abort. Combined with the SessionMetadata
 982                 // hook, this can allow for tying a session to an IP address or the
 983                 // like.
 984                 $reason = 'Hook aborted';
 985                 if ( !\Hooks::run(
 986                         'SessionCheckInfo',
 987                         [ &$reason, $info, $request, $metadata, $data ]
 988                 ) ) {
 989                         $this->logger->warning( 'Session "{session}": ' . $reason, [
 990                                 'session' => $info,
 991                         ] );
 992                         return $failHandler();
 993                 }
 994
 995                 return true;
 996         }
 997
 998         /**
 999          * Create a session corresponding to the passed SessionInfo
1000          * @private For use by a SessionProvider that needs to specially create its
1001          *  own session.
1002          * @param SessionInfo $info
1003          * @param WebRequest $request
1004          * @return Session
1005          */
1006         public function getSessionFromInfo( SessionInfo $info, WebRequest $request ) {
1007                 // @codeCoverageIgnoreStart
1008                 if ( defined( 'MW_NO_SESSION' ) ) {
1009                         if ( MW_NO_SESSION === 'warn' ) {
1010                                 // Undocumented safety case for converting existing entry points
1011                                 $this->logger->error( 'Sessions are supposed to be disabled for this entry point', [
1012                                         'exception' => new \BadMethodCallException( 'Sessions are disabled for this entry point' ),
1013                                 ] );
1014                         } else {
1015                                 throw new \BadMethodCallException( 'Sessions are disabled for this entry point' );
1016                         }
1017                 }
1018                 // @codeCoverageIgnoreEnd
1019
1020                 $id = $info->getId();
1021
1022                 if ( !isset( $this->allSessionBackends[$id] ) ) {
1023                         if ( !isset( $this->allSessionIds[$id] ) ) {
1024                                 $this->allSessionIds[$id] = new SessionId( $id );
1025                         }
1026                         $backend = new SessionBackend(
1027                                 $this->allSessionIds[$id],
1028                                 $info,
1029                                 $this->store,
1030                                 $this->logger,
1031                                 $this->config->get( 'ObjectCacheSessionExpiry' )
1032                         );
1033                         $this->allSessionBackends[$id] = $backend;
1034                         $delay = $backend->delaySave();
1035                 } else {
1036                         $backend = $this->allSessionBackends[$id];
1037                         $delay = $backend->delaySave();
1038                         if ( $info->wasPersisted() ) {
1039                                 $backend->persist();
1040                         }
1041                         if ( $info->wasRemembered() ) {
1042                                 $backend->setRememberUser( true );
1043                         }
1044                 }
1045
1046                 $request->setSessionId( $backend->getSessionId() );
1047                 $session = $backend->getSession( $request );
1048
1049                 if ( !$info->isIdSafe() ) {
1050                         $session->resetId();
1051                 }
1052
1053                 \ScopedCallback::consume( $delay );
1054                 return $session;
1055         }
1056
1057         /**
1058          * Deregister a SessionBackend
1059          * @private For use from \MediaWiki\Session\SessionBackend only
1060          * @param SessionBackend $backend
1061          */
1062         public function deregisterSessionBackend( SessionBackend $backend ) {
1063                 $id = $backend->getId();
1064                 if ( !isset( $this->allSessionBackends[$id] ) || !isset( $this->allSessionIds[$id] ) ||
1065                         $this->allSessionBackends[$id] !== $backend ||
1066                         $this->allSessionIds[$id] !== $backend->getSessionId()
1067                 ) {
1068                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
1069                 }
1070
1071                 unset( $this->allSessionBackends[$id] );
1072                 // Explicitly do not unset $this->allSessionIds[$id]
1073         }
1074
1075         /**
1076          * Change a SessionBackend's ID
1077          * @private For use from \MediaWiki\Session\SessionBackend only
1078          * @param SessionBackend $backend
1079          */
1080         public function changeBackendId( SessionBackend $backend ) {
1081                 $sessionId = $backend->getSessionId();
1082                 $oldId = (string)$sessionId;
1083                 if ( !isset( $this->allSessionBackends[$oldId] ) || !isset( $this->allSessionIds[$oldId] ) ||
1084                         $this->allSessionBackends[$oldId] !== $backend ||
1085                         $this->allSessionIds[$oldId] !== $sessionId
1086                 ) {
1087                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
1088                 }
1089
1090                 $newId = $this->generateSessionId();
1091
1092                 unset( $this->allSessionBackends[$oldId], $this->allSessionIds[$oldId] );
1093                 $sessionId->setId( $newId );
1094                 $this->allSessionBackends[$newId] = $backend;
1095                 $this->allSessionIds[$newId] = $sessionId;
1096         }
1097
1098         /**
1099          * Generate a new random session ID
1100          * @return string
1101          */
1102         public function generateSessionId() {
1103                 do {
1104                         $id = \Wikimedia\base_convert( \MWCryptRand::generateHex( 40 ), 16, 32, 32 );
1105                         $key = wfMemcKey( 'MWSession', $id );
1106                 } while ( isset( $this->allSessionIds[$id] ) || is_array( $this->store->get( $key ) ) );
1107                 return $id;
1108         }
1109
1110         /**
1111          * Call setters on a PHPSessionHandler
1112          * @private Use PhpSessionHandler::install()
1113          * @param PHPSessionHandler $handler
1114          */
1115         public function setupPHPSessionHandler( PHPSessionHandler $handler ) {
1116                 $handler->setManager( $this, $this->store, $this->logger );
1117         }
1118
1119         /**
1120          * Reset the internal caching for unit testing
1121          */
1122         public static function resetCache() {
1123                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
1124                         // @codeCoverageIgnoreStart
1125                         throw new MWException( __METHOD__ . ' may only be called from unit tests!' );
1126                         // @codeCoverageIgnoreEnd
1127                 }
1128
1129                 self::$globalSession = null;
1130                 self::$globalSessionRequest = null;
1131         }
1132
1133         /**@}*/
1134
1135 }