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