includes/session/SessionManager.php

   1 <?php
   2 /**
   3  * MediaWiki\Session entry point
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Session
  22  */
  23
  24 namespace MediaWiki\Session;
  25
  26 use Psr\Log\LoggerInterface;
  27 use BagOStuff;
  28 use CachedBagOStuff;
  29 use Config;
  30 use FauxRequest;
  31 use Language;
  32 use Message;
  33 use User;
  34 use WebRequest;
  35
  36 /**
  37  * This serves as the entry point to the MediaWiki session handling system.
  38  *
  39  * @ingroup Session
  40  * @since 1.27
  41  */
  42 final class SessionManager implements SessionManagerInterface {
  43         /** @var SessionManager|null */
  44         private static $instance = null;
  45
  46         /** @var Session|null */
  47         private static $globalSession = null;
  48
  49         /** @var WebRequest|null */
  50         private static $globalSessionRequest = null;
  51
  52         /** @var LoggerInterface */
  53         private $logger;
  54
  55         /** @var Config */
  56         private $config;
  57
  58         /** @var CachedBagOStuff|null */
  59         private $store;
  60
  61         /** @var SessionProvider[] */
  62         private $sessionProviders = null;
  63
  64         /** @var string[] */
  65         private $varyCookies = null;
  66
  67         /** @var array */
  68         private $varyHeaders = null;
  69
  70         /** @var SessionBackend[] */
  71         private $allSessionBackends = array();
  72
  73         /** @var SessionId[] */
  74         private $allSessionIds = array();
  75
  76         /** @var string[] */
  77         private $preventUsers = array();
  78
  79         /**
  80          * Get the global SessionManager
  81          * @return SessionManagerInterface
  82          *  (really a SessionManager, but this is to make IDEs less confused)
  83          */
  84         public static function singleton() {
  85                 if ( self::$instance === null ) {
  86                         self::$instance = new self();
  87                 }
  88                 return self::$instance;
  89         }
  90
  91         /**
  92          * Get the "global" session
  93          *
  94          * If PHP's session_id() has been set, returns that session. Otherwise
  95          * returns the session for RequestContext::getMain()->getRequest().
  96          *
  97          * @return Session
  98          */
  99         public static function getGlobalSession() {
 100                 if ( !PHPSessionHandler::isEnabled() ) {
 101                         $id = '';
 102                 } else {
 103                         $id = session_id();
 104                 }
 105
 106                 $request = \RequestContext::getMain()->getRequest();
 107                 if (
 108                         !self::$globalSession // No global session is set up yet
 109                         || self::$globalSessionRequest !== $request // The global WebRequest changed
 110                         || $id !== '' && self::$globalSession->getId() !== $id // Someone messed with session_id()
 111                 ) {
 112                         self::$globalSessionRequest = $request;
 113                         if ( $id === '' ) {
 114                                 // session_id() wasn't used, so fetch the Session from the WebRequest.
 115                                 // We use $request->getSession() instead of $singleton->getSessionForRequest()
 116                                 // because doing the latter would require a public
 117                                 // "$request->getSessionId()" method that would confuse end
 118                                 // users by returning SessionId|null where they'd expect it to
 119                                 // be short for $request->getSession()->getId(), and would
 120                                 // wind up being a duplicate of the code in
 121                                 // $request->getSession() anyway.
 122                                 self::$globalSession = $request->getSession();
 123                         } else {
 124                                 // Someone used session_id(), so we need to follow suit.
 125                                 // Note this overwrites whatever session might already be
 126                                 // associated with $request with the one for $id.
 127                                 self::$globalSession = self::singleton()->getSessionById( $id, true, $request )
 128                                         ?: $request->getSession();
 129                         }
 130                 }
 131                 return self::$globalSession;
 132         }
 133
 134         /**
 135          * @param array $options
 136          *  - config: Config to fetch configuration from. Defaults to the default 'main' config.
 137          *  - logger: LoggerInterface to use for logging. Defaults to the 'session' channel.
 138          *  - store: BagOStuff to store session data in.
 139          */
 140         public function __construct( $options = array() ) {
 141                 if ( isset( $options['config'] ) ) {
 142                         $this->config = $options['config'];
 143                         if ( !$this->config instanceof Config ) {
 144                                 throw new \InvalidArgumentException(
 145                                         '$options[\'config\'] must be an instance of Config'
 146                                 );
 147                         }
 148                 } else {
 149                         $this->config = \ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 150                 }
 151
 152                 if ( isset( $options['logger'] ) ) {
 153                         if ( !$options['logger'] instanceof LoggerInterface ) {
 154                                 throw new \InvalidArgumentException(
 155                                         '$options[\'logger\'] must be an instance of LoggerInterface'
 156                                 );
 157                         }
 158                         $this->setLogger( $options['logger'] );
 159                 } else {
 160                         $this->setLogger( \MediaWiki\Logger\LoggerFactory::getInstance( 'session' ) );
 161                 }
 162
 163                 if ( isset( $options['store'] ) ) {
 164                         if ( !$options['store'] instanceof BagOStuff ) {
 165                                 throw new \InvalidArgumentException(
 166                                         '$options[\'store\'] must be an instance of BagOStuff'
 167                                 );
 168                         }
 169                         $store = $options['store'];
 170                 } else {
 171                         $store = \ObjectCache::getInstance( $this->config->get( 'SessionCacheType' ) );
 172                         $store->setLogger( $this->logger );
 173                 }
 174                 $this->store = $store instanceof CachedBagOStuff ? $store : new CachedBagOStuff( $store );
 175
 176                 register_shutdown_function( array( $this, 'shutdown' ) );
 177         }
 178
 179         public function setLogger( LoggerInterface $logger ) {
 180                 $this->logger = $logger;
 181         }
 182
 183         public function getSessionForRequest( WebRequest $request ) {
 184                 $info = $this->getSessionInfoForRequest( $request );
 185
 186                 if ( !$info ) {
 187                         $session = $this->getEmptySession( $request );
 188                 } else {
 189                         $session = $this->getSessionFromInfo( $info, $request );
 190                 }
 191                 return $session;
 192         }
 193
 194         public function getSessionById( $id, $create = false, WebRequest $request = null ) {
 195                 if ( !self::validateSessionId( $id ) ) {
 196                         throw new \InvalidArgumentException( 'Invalid session ID' );
 197                 }
 198                 if ( !$request ) {
 199                         $request = new FauxRequest;
 200                 }
 201
 202                 $session = null;
 203
 204                 // Test this here to provide a better log message for the common case
 205                 // of "no such ID"
 206                 $key = wfMemcKey( 'MWSession', $id );
 207                 if ( is_array( $this->store->get( $key ) ) ) {
 208                         $info = new SessionInfo( SessionInfo::MIN_PRIORITY, array( 'id' => $id, 'idIsSafe' => true ) );
 209                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 210                                 $session = $this->getSessionFromInfo( $info, $request );
 211                         }
 212                 }
 213
 214                 if ( $create && $session === null ) {
 215                         $ex = null;
 216                         try {
 217                                 $session = $this->getEmptySessionInternal( $request, $id );
 218                         } catch ( \Exception $ex ) {
 219                                 $this->logger->error( __METHOD__ . ': failed to create empty session: ' .
 220                                         $ex->getMessage() );
 221                                 $session = null;
 222                         }
 223                 }
 224
 225                 return $session;
 226         }
 227
 228         public function getEmptySession( WebRequest $request = null ) {
 229                 return $this->getEmptySessionInternal( $request );
 230         }
 231
 232         /**
 233          * @see SessionManagerInterface::getEmptySession
 234          * @param WebRequest|null $request
 235          * @param string|null $id ID to force on the new session
 236          * @return Session
 237          */
 238         private function getEmptySessionInternal( WebRequest $request = null, $id = null ) {
 239                 if ( $id !== null ) {
 240                         if ( !self::validateSessionId( $id ) ) {
 241                                 throw new \InvalidArgumentException( 'Invalid session ID' );
 242                         }
 243
 244                         $key = wfMemcKey( 'MWSession', $id );
 245                         if ( is_array( $this->store->get( $key ) ) ) {
 246                                 throw new \InvalidArgumentException( 'Session ID already exists' );
 247                         }
 248                 }
 249                 if ( !$request ) {
 250                         $request = new FauxRequest;
 251                 }
 252
 253                 $infos = array();
 254                 foreach ( $this->getProviders() as $provider ) {
 255                         $info = $provider->newSessionInfo( $id );
 256                         if ( !$info ) {
 257                                 continue;
 258                         }
 259                         if ( $info->getProvider() !== $provider ) {
 260                                 throw new \UnexpectedValueException(
 261                                         "$provider returned an empty session info for a different provider: $info"
 262                                 );
 263                         }
 264                         if ( $id !== null && $info->getId() !== $id ) {
 265                                 throw new \UnexpectedValueException(
 266                                         "$provider returned empty session info with a wrong id: " .
 267                                                 $info->getId() . ' != ' . $id
 268                                 );
 269                         }
 270                         if ( !$info->isIdSafe() ) {
 271                                 throw new \UnexpectedValueException(
 272                                         "$provider returned empty session info with id flagged unsafe"
 273                                 );
 274                         }
 275                         $compare = $infos ? SessionInfo::compare( $infos[0], $info ) : -1;
 276                         if ( $compare > 0 ) {
 277                                 continue;
 278                         }
 279                         if ( $compare === 0 ) {
 280                                 $infos[] = $info;
 281                         } else {
 282                                 $infos = array( $info );
 283                         }
 284                 }
 285
 286                 // Make sure there's exactly one
 287                 if ( count( $infos ) > 1 ) {
 288                         throw new \UnexpectedValueException(
 289                                 'Multiple empty sessions tied for top priority: ' . join( ', ', $infos )
 290                         );
 291                 } elseif ( count( $infos ) < 1 ) {
 292                         throw new \UnexpectedValueException( 'No provider could provide an empty session!' );
 293                 }
 294
 295                 return $this->getSessionFromInfo( $infos[0], $request );
 296         }
 297
 298         public function getVaryHeaders() {
 299                 if ( $this->varyHeaders === null ) {
 300                         $headers = array();
 301                         foreach ( $this->getProviders() as $provider ) {
 302                                 foreach ( $provider->getVaryHeaders() as $header => $options ) {
 303                                         if ( !isset( $headers[$header] ) ) {
 304                                                 $headers[$header] = array();
 305                                         }
 306                                         if ( is_array( $options ) ) {
 307                                                 $headers[$header] = array_unique( array_merge( $headers[$header], $options ) );
 308                                         }
 309                                 }
 310                         }
 311                         $this->varyHeaders = $headers;
 312                 }
 313                 return $this->varyHeaders;
 314         }
 315
 316         public function getVaryCookies() {
 317                 if ( $this->varyCookies === null ) {
 318                         $cookies = array();
 319                         foreach ( $this->getProviders() as $provider ) {
 320                                 $cookies = array_merge( $cookies, $provider->getVaryCookies() );
 321                         }
 322                         $this->varyCookies = array_values( array_unique( $cookies ) );
 323                 }
 324                 return $this->varyCookies;
 325         }
 326
 327         /**
 328          * Validate a session ID
 329          * @param string $id
 330          * @return bool
 331          */
 332         public static function validateSessionId( $id ) {
 333                 return is_string( $id ) && preg_match( '/^[a-zA-Z0-9_-]{32,}$/', $id );
 334         }
 335
 336         /**
 337          * @name Internal methods
 338          * @{
 339          */
 340
 341         /**
 342          * Auto-create the given user, if necessary
 343          * @private Don't call this yourself. Let Setup.php do it for you at the right time.
 344          * @note This more properly belongs in AuthManager, but we need it now.
 345          *  When AuthManager comes, this will be deprecated and will pass-through
 346          *  to the corresponding AuthManager method.
 347          * @param User $user User to auto-create
 348          * @return bool Success
 349          */
 350         public static function autoCreateUser( User $user ) {
 351                 global $wgAuth;
 352
 353                 $logger = self::singleton()->logger;
 354
 355                 // Much of this code is based on that in CentralAuth
 356
 357                 // Try the local user from the slave DB
 358                 $localId = User::idFromName( $user->getName() );
 359
 360                 // Fetch the user ID from the master, so that we don't try to create the user
 361                 // when they already exist, due to replication lag
 362                 // @codeCoverageIgnoreStart
 363                 if ( !$localId && wfGetLB()->getReaderIndex() != 0 ) {
 364                         $localId = User::idFromName( $user->getName(), User::READ_LATEST );
 365                 }
 366                 // @codeCoverageIgnoreEnd
 367
 368                 if ( $localId ) {
 369                         // User exists after all.
 370                         $user->setId( $localId );
 371                         $user->loadFromId();
 372                         return false;
 373                 }
 374
 375                 // Denied by AuthPlugin? But ignore AuthPlugin itself.
 376                 if ( get_class( $wgAuth ) !== 'AuthPlugin' && !$wgAuth->autoCreate() ) {
 377                         $logger->debug( __METHOD__ . ': denied by AuthPlugin' );
 378                         $user->setId( 0 );
 379                         $user->loadFromId();
 380                         return false;
 381                 }
 382
 383                 // Wiki is read-only?
 384                 if ( wfReadOnly() ) {
 385                         $logger->debug( __METHOD__ . ': denied by wfReadOnly()' );
 386                         $user->setId( 0 );
 387                         $user->loadFromId();
 388                         return false;
 389                 }
 390
 391                 $userName = $user->getName();
 392
 393                 // Check the session, if we tried to create this user already there's
 394                 // no point in retrying.
 395                 $session = self::getGlobalSession();
 396                 $reason = $session->get( 'MWSession::AutoCreateBlacklist' );
 397                 if ( $reason ) {
 398                         $logger->debug( __METHOD__ . ": blacklisted in session ($reason)" );
 399                         $user->setId( 0 );
 400                         $user->loadFromId();
 401                         return false;
 402                 }
 403
 404                 // Is the IP user able to create accounts?
 405                 $anon = new User;
 406                 if ( !$anon->isAllowedAny( 'createaccount', 'autocreateaccount' )
 407                         || $anon->isBlockedFromCreateAccount()
 408                 ) {
 409                         // Blacklist the user to avoid repeated DB queries subsequently
 410                         $logger->debug( __METHOD__ . ': user is blocked from this wiki, blacklisting' );
 411                         $session->set( 'MWSession::AutoCreateBlacklist', 'blocked', 600 );
 412                         $session->persist();
 413                         $user->setId( 0 );
 414                         $user->loadFromId();
 415                         return false;
 416                 }
 417
 418                 // Check for validity of username
 419                 if ( !User::isCreatableName( $userName ) ) {
 420                         $logger->debug( __METHOD__ . ': Invalid username, blacklisting' );
 421                         $session->set( 'MWSession::AutoCreateBlacklist', 'invalid username', 600 );
 422                         $session->persist();
 423                         $user->setId( 0 );
 424                         $user->loadFromId();
 425                         return false;
 426                 }
 427
 428                 // Give other extensions a chance to stop auto creation.
 429                 $user->loadDefaults( $userName );
 430                 $abortMessage = '';
 431                 if ( !\Hooks::run( 'AbortAutoAccount', array( $user, &$abortMessage ) ) ) {
 432                         // In this case we have no way to return the message to the user,
 433                         // but we can log it.
 434                         $logger->debug( __METHOD__ . ": denied by hook: $abortMessage" );
 435                         $session->set( 'MWSession::AutoCreateBlacklist', "hook aborted: $abortMessage", 600 );
 436                         $session->persist();
 437                         $user->setId( 0 );
 438                         $user->loadFromId();
 439                         return false;
 440                 }
 441
 442                 // Make sure the name has not been changed
 443                 if ( $user->getName() !== $userName ) {
 444                         $user->setId( 0 );
 445                         $user->loadFromId();
 446                         throw new \UnexpectedValueException(
 447                                 'AbortAutoAccount hook tried to change the user name'
 448                         );
 449                 }
 450
 451                 // Ignore warnings about master connections/writes...hard to avoid here
 452                 \Profiler::instance()->getTransactionProfiler()->resetExpectations();
 453
 454                 $cache = \ObjectCache::getLocalClusterInstance();
 455                 $backoffKey = wfMemcKey( 'MWSession', 'autocreate-failed', md5( $userName ) );
 456                 if ( $cache->get( $backoffKey ) ) {
 457                         $logger->debug( __METHOD__ . ': denied by prior creation attempt failures' );
 458                         $user->setId( 0 );
 459                         $user->loadFromId();
 460                         return false;
 461                 }
 462
 463                 // Checks passed, create the user...
 464                 $from = isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : 'CLI';
 465                 $logger->info( __METHOD__ . ": creating new user ($userName) - from: $from" );
 466
 467                 try {
 468                         // Insert the user into the local DB master
 469                         $status = $user->addToDatabase();
 470                         if ( !$status->isOK() ) {
 471                                 // @codeCoverageIgnoreStart
 472                                 $logger->error( __METHOD__ . ': failed with message ' . $status->getWikiText() );
 473                                 $user->setId( 0 );
 474                                 $user->loadFromId();
 475                                 return false;
 476                                 // @codeCoverageIgnoreEnd
 477                         }
 478                 } catch ( \Exception $ex ) {
 479                         // @codeCoverageIgnoreStart
 480                         $logger->error( __METHOD__ . ': failed with exception ' . $ex->getMessage() );
 481                         // Do not keep throwing errors for a while
 482                         $cache->set( $backoffKey, 1, 600 );
 483                         // Bubble up error; which should normally trigger DB rollbacks
 484                         throw $ex;
 485                         // @codeCoverageIgnoreEnd
 486                 }
 487
 488                 # Notify AuthPlugin
 489                 $tmpUser = $user;
 490                 $wgAuth->initUser( $tmpUser, true );
 491                 if ( $tmpUser !== $user ) {
 492                         $logger->warning( __METHOD__ . ': ' .
 493                                 get_class( $wgAuth ) . '::initUser() replaced the user object' );
 494                 }
 495
 496                 # Notify hooks (e.g. Newuserlog)
 497                 \Hooks::run( 'AuthPluginAutoCreate', array( $user ) );
 498                 \Hooks::run( 'LocalUserCreated', array( $user, true ) );
 499
 500                 $user->saveSettings();
 501
 502                 # Update user count
 503                 \DeferredUpdates::addUpdate( new \SiteStatsUpdate( 0, 0, 0, 0, 1 ) );
 504
 505                 # Watch user's userpage and talk page
 506                 $user->addWatch( $user->getUserPage(), \WatchedItem::IGNORE_USER_RIGHTS );
 507
 508                 return true;
 509         }
 510
 511         /**
 512          * Prevent future sessions for the user
 513          *
 514          * The intention is that the named account will never again be usable for
 515          * normal login (i.e. there is no way to undo the prevention of access).
 516          *
 517          * @private For use from \\User::newSystemUser only
 518          * @param string $username
 519          */
 520         public function preventSessionsForUser( $username ) {
 521                 $this->preventUsers[$username] = true;
 522
 523                 // Reset the user's token to kill existing sessions
 524                 $user = User::newFromName( $username );
 525                 if ( $user && $user->getToken( false ) ) {
 526                         $user->setToken();
 527                         $user->saveSettings();
 528                 }
 529
 530                 // Instruct the session providers to kill any other sessions too.
 531                 foreach ( $this->getProviders() as $provider ) {
 532                         $provider->preventSessionsForUser( $username );
 533                 }
 534         }
 535
 536         /**
 537          * Test if a user is prevented
 538          * @private For use from SessionBackend only
 539          * @param string $username
 540          * @return bool
 541          */
 542         public function isUserSessionPrevented( $username ) {
 543                 return !empty( $this->preventUsers[$username] );
 544         }
 545
 546         /**
 547          * Get the available SessionProviders
 548          * @return SessionProvider[]
 549          */
 550         protected function getProviders() {
 551                 if ( $this->sessionProviders === null ) {
 552                         $this->sessionProviders = array();
 553                         foreach ( $this->config->get( 'SessionProviders' ) as $spec ) {
 554                                 $provider = \ObjectFactory::getObjectFromSpec( $spec );
 555                                 $provider->setLogger( $this->logger );
 556                                 $provider->setConfig( $this->config );
 557                                 $provider->setManager( $this );
 558                                 if ( isset( $this->sessionProviders[(string)$provider] ) ) {
 559                                         throw new \UnexpectedValueException( "Duplicate provider name \"$provider\"" );
 560                                 }
 561                                 $this->sessionProviders[(string)$provider] = $provider;
 562                         }
 563                 }
 564                 return $this->sessionProviders;
 565         }
 566
 567         /**
 568          * Get a session provider by name
 569          *
 570          * Generally, this will only be used by internal implementation of some
 571          * special session-providing mechanism. General purpose code, if it needs
 572          * to access a SessionProvider at all, will use Session::getProvider().
 573          *
 574          * @param string $name
 575          * @return SessionProvider|null
 576          */
 577         public function getProvider( $name ) {
 578                 $providers = $this->getProviders();
 579                 return isset( $providers[$name] ) ? $providers[$name] : null;
 580         }
 581
 582         /**
 583          * Save all active sessions on shutdown
 584          * @private For internal use with register_shutdown_function()
 585          */
 586         public function shutdown() {
 587                 if ( $this->allSessionBackends ) {
 588                         $this->logger->debug( 'Saving all sessions on shutdown' );
 589                         if ( session_id() !== '' ) {
 590                                 // @codeCoverageIgnoreStart
 591                                 session_write_close();
 592                         }
 593                         // @codeCoverageIgnoreEnd
 594                         foreach ( $this->allSessionBackends as $backend ) {
 595                                 $backend->save( true );
 596                         }
 597                 }
 598         }
 599
 600         /**
 601          * Fetch the SessionInfo(s) for a request
 602          * @param WebRequest $request
 603          * @return SessionInfo|null
 604          */
 605         private function getSessionInfoForRequest( WebRequest $request ) {
 606                 // Call all providers to fetch "the" session
 607                 $infos = array();
 608                 foreach ( $this->getProviders() as $provider ) {
 609                         $info = $provider->provideSessionInfo( $request );
 610                         if ( !$info ) {
 611                                 continue;
 612                         }
 613                         if ( $info->getProvider() !== $provider ) {
 614                                 throw new \UnexpectedValueException(
 615                                         "$provider returned session info for a different provider: $info"
 616                                 );
 617                         }
 618                         $infos[] = $info;
 619                 }
 620
 621                 // Sort the SessionInfos. Then find the first one that can be
 622                 // successfully loaded, and then all the ones after it with the same
 623                 // priority.
 624                 usort( $infos, 'MediaWiki\\Session\\SessionInfo::compare' );
 625                 $retInfos = array();
 626                 while ( $infos ) {
 627                         $info = array_pop( $infos );
 628                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 629                                 $retInfos[] = $info;
 630                                 while ( $infos ) {
 631                                         $info = array_pop( $infos );
 632                                         if ( SessionInfo::compare( $retInfos[0], $info ) ) {
 633                                                 // We hit a lower priority, stop checking.
 634                                                 break;
 635                                         }
 636                                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 637                                                 // This is going to error out below, but we want to
 638                                                 // provide a complete list.
 639                                                 $retInfos[] = $info;
 640                                         }
 641                                 }
 642                         }
 643                 }
 644
 645                 if ( count( $retInfos ) > 1 ) {
 646                         $ex = new \OverflowException(
 647                                 'Multiple sessions for this request tied for top priority: ' . join( ', ', $retInfos )
 648                         );
 649                         $ex->sessionInfos = $retInfos;
 650                         throw $ex;
 651                 }
 652
 653                 return $retInfos ? $retInfos[0] : null;
 654         }
 655
 656         /**
 657          * Load and verify the session info against the store
 658          *
 659          * @param SessionInfo &$info Will likely be replaced with an updated SessionInfo instance
 660          * @param WebRequest $request
 661          * @return bool Whether the session info matches the stored data (if any)
 662          */
 663         private function loadSessionInfoFromStore( SessionInfo &$info, WebRequest $request ) {
 664                 $key = wfMemcKey( 'MWSession', $info->getId() );
 665                 $blob = $this->store->get( $key );
 666
 667                 $newParams = array();
 668
 669                 if ( $blob !== false ) {
 670                         // Sanity check: blob must be an array, if it's saved at all
 671                         if ( !is_array( $blob ) ) {
 672                                 $this->logger->warning( "Session $info: Bad data" );
 673                                 $this->store->delete( $key );
 674                                 return false;
 675                         }
 676
 677                         // Sanity check: blob has data and metadata arrays
 678                         if ( !isset( $blob['data'] ) || !is_array( $blob['data'] ) ||
 679                                 !isset( $blob['metadata'] ) || !is_array( $blob['metadata'] )
 680                         ) {
 681                                 $this->logger->warning( "Session $info: Bad data structure" );
 682                                 $this->store->delete( $key );
 683                                 return false;
 684                         }
 685
 686                         $data = $blob['data'];
 687                         $metadata = $blob['metadata'];
 688
 689                         // Sanity check: metadata must be an array and must contain certain
 690                         // keys, if it's saved at all
 691                         if ( !array_key_exists( 'userId', $metadata ) ||
 692                                 !array_key_exists( 'userName', $metadata ) ||
 693                                 !array_key_exists( 'userToken', $metadata ) ||
 694                                 !array_key_exists( 'provider', $metadata )
 695                         ) {
 696                                 $this->logger->warning( "Session $info: Bad metadata" );
 697                                 $this->store->delete( $key );
 698                                 return false;
 699                         }
 700
 701                         // First, load the provider from metadata, or validate it against the metadata.
 702                         $provider = $info->getProvider();
 703                         if ( $provider === null ) {
 704                                 $newParams['provider'] = $provider = $this->getProvider( $metadata['provider'] );
 705                                 if ( !$provider ) {
 706                                         $this->logger->warning( "Session $info: Unknown provider, " . $metadata['provider'] );
 707                                         $this->store->delete( $key );
 708                                         return false;
 709                                 }
 710                         } elseif ( $metadata['provider'] !== (string)$provider ) {
 711                                 $this->logger->warning( "Session $info: Wrong provider, " .
 712                                         $metadata['provider'] . ' !== ' . $provider );
 713                                 return false;
 714                         }
 715
 716                         // Load provider metadata from metadata, or validate it against the metadata
 717                         $providerMetadata = $info->getProviderMetadata();
 718                         if ( isset( $metadata['providerMetadata'] ) ) {
 719                                 if ( $providerMetadata === null ) {
 720                                         $newParams['metadata'] = $metadata['providerMetadata'];
 721                                 } else {
 722                                         try {
 723                                                 $newProviderMetadata = $provider->mergeMetadata(
 724                                                         $metadata['providerMetadata'], $providerMetadata
 725                                                 );
 726                                                 if ( $newProviderMetadata !== $providerMetadata ) {
 727                                                         $newParams['metadata'] = $newProviderMetadata;
 728                                                 }
 729                                         } catch ( \UnexpectedValueException $ex ) {
 730                                                 $this->logger->warning( "Session $info: Metadata merge failed: " . $ex->getMessage() );
 731                                                 return false;
 732                                         }
 733                                 }
 734                         }
 735
 736                         // Next, load the user from metadata, or validate it against the metadata.
 737                         $userInfo = $info->getUserInfo();
 738                         if ( !$userInfo ) {
 739                                 // For loading, id is preferred to name.
 740                                 try {
 741                                         if ( $metadata['userId'] ) {
 742                                                 $userInfo = UserInfo::newFromId( $metadata['userId'] );
 743                                         } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 744                                                 $userInfo = UserInfo::newFromName( $metadata['userName'] );
 745                                         } else {
 746                                                 $userInfo = UserInfo::newAnonymous();
 747                                         }
 748                                 } catch ( \InvalidArgumentException $ex ) {
 749                                         $this->logger->error( "Session $info: " . $ex->getMessage() );
 750                                         return false;
 751                                 }
 752                                 $newParams['userInfo'] = $userInfo;
 753                         } else {
 754                                 // User validation passes if user ID matches, or if there
 755                                 // is no saved ID and the names match.
 756                                 if ( $metadata['userId'] ) {
 757                                         if ( $metadata['userId'] !== $userInfo->getId() ) {
 758                                                 $this->logger->warning( "Session $info: User ID mismatch, " .
 759                                                         $metadata['userId'] . ' !== ' . $userInfo->getId() );
 760                                                 return false;
 761                                         }
 762
 763                                         // If the user was renamed, probably best to fail here.
 764                                         if ( $metadata['userName'] !== null &&
 765                                                 $userInfo->getName() !== $metadata['userName']
 766                                         ) {
 767                                                 $this->logger->warning( "Session $info: User ID matched but name didn't (rename?), " .
 768                                                         $metadata['userName'] . ' !== ' . $userInfo->getName() );
 769                                                 return false;
 770                                         }
 771
 772                                 } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 773                                         if ( $metadata['userName'] !== $userInfo->getName() ) {
 774                                                 $this->logger->warning( "Session $info: User name mismatch, " .
 775                                                         $metadata['userName'] . ' !== ' . $userInfo->getName() );
 776                                                 return false;
 777                                         }
 778                                 } elseif ( !$userInfo->isAnon() ) {
 779                                         // Metadata specifies an anonymous user, but the passed-in
 780                                         // user isn't anonymous.
 781                                         $this->logger->warning(
 782                                                 "Session $info: Metadata has an anonymous user, " .
 783                                                         'but a non-anon user was provided'
 784                                         );
 785                                         return false;
 786                                 }
 787                         }
 788
 789                         // And if we have a token in the metadata, it must match the loaded/provided user.
 790                         if ( $metadata['userToken'] !== null &&
 791                                 $userInfo->getToken() !== $metadata['userToken']
 792                         ) {
 793                                 $this->logger->warning( "Session $info: User token mismatch" );
 794                                 return false;
 795                         }
 796                         if ( !$userInfo->isVerified() ) {
 797                                 $newParams['userInfo'] = $userInfo->verified();
 798                         }
 799
 800                         if ( !empty( $metadata['remember'] ) && !$info->wasRemembered() ) {
 801                                 $newParams['remembered'] = true;
 802                         }
 803                         if ( !empty( $metadata['forceHTTPS'] ) && !$info->forceHTTPS() ) {
 804                                 $newParams['forceHTTPS'] = true;
 805                         }
 806                         if ( !empty( $metadata['persisted'] ) && !$info->wasPersisted() ) {
 807                                 $newParams['persisted'] = true;
 808                         }
 809
 810                         if ( !$info->isIdSafe() ) {
 811                                 $newParams['idIsSafe'] = true;
 812                         }
 813                 } else {
 814                         // No metadata, so we can't load the provider if one wasn't given.
 815                         if ( $info->getProvider() === null ) {
 816                                 $this->logger->warning( "Session $info: Null provider and no metadata" );
 817                                 return false;
 818                         }
 819
 820                         // If no user was provided and no metadata, it must be anon.
 821                         if ( !$info->getUserInfo() ) {
 822                                 if ( $info->getProvider()->canChangeUser() ) {
 823                                         $newParams['userInfo'] = UserInfo::newAnonymous();
 824                                 } else {
 825                                         $this->logger->info(
 826                                                 "Session $info: No user provided and provider cannot set user"
 827                                         );
 828                                         return false;
 829                                 }
 830                         } elseif ( !$info->getUserInfo()->isVerified() ) {
 831                                 $this->logger->warning(
 832                                         "Session $info: Unverified user provided and no metadata to auth it"
 833                                 );
 834                                 return false;
 835                         }
 836
 837                         $data = false;
 838                         $metadata = false;
 839
 840                         if ( !$info->getProvider()->persistsSessionId() && !$info->isIdSafe() ) {
 841                                 // The ID doesn't come from the user, so it should be safe
 842                                 // (and if not, nothing we can do about it anyway)
 843                                 $newParams['idIsSafe'] = true;
 844                         }
 845                 }
 846
 847                 // Construct the replacement SessionInfo, if necessary
 848                 if ( $newParams ) {
 849                         $newParams['copyFrom'] = $info;
 850                         $info = new SessionInfo( $info->getPriority(), $newParams );
 851                 }
 852
 853                 // Allow the provider to check the loaded SessionInfo
 854                 $providerMetadata = $info->getProviderMetadata();
 855                 if ( !$info->getProvider()->refreshSessionInfo( $info, $request, $providerMetadata ) ) {
 856                         return false;
 857                 }
 858                 if ( $providerMetadata !== $info->getProviderMetadata() ) {
 859                         $info = new SessionInfo( $info->getPriority(), array(
 860                                 'metadata' => $providerMetadata,
 861                                 'copyFrom' => $info,
 862                         ) );
 863                 }
 864
 865                 // Give hooks a chance to abort. Combined with the SessionMetadata
 866                 // hook, this can allow for tying a session to an IP address or the
 867                 // like.
 868                 $reason = 'Hook aborted';
 869                 if ( !\Hooks::run(
 870                         'SessionCheckInfo',
 871                         array( &$reason, $info, $request, $metadata, $data )
 872                 ) ) {
 873                         $this->logger->warning( "Session $info: $reason" );
 874                         return false;
 875                 }
 876
 877                 return true;
 878         }
 879
 880         /**
 881          * Create a session corresponding to the passed SessionInfo
 882          * @private For use by a SessionProvider that needs to specially create its
 883          *  own session.
 884          * @param SessionInfo $info
 885          * @param WebRequest $request
 886          * @return Session
 887          */
 888         public function getSessionFromInfo( SessionInfo $info, WebRequest $request ) {
 889                 $id = $info->getId();
 890
 891                 if ( !isset( $this->allSessionBackends[$id] ) ) {
 892                         if ( !isset( $this->allSessionIds[$id] ) ) {
 893                                 $this->allSessionIds[$id] = new SessionId( $id );
 894                         }
 895                         $backend = new SessionBackend(
 896                                 $this->allSessionIds[$id],
 897                                 $info,
 898                                 $this->store,
 899                                 $this->logger,
 900                                 $this->config->get( 'ObjectCacheSessionExpiry' )
 901                         );
 902                         $this->allSessionBackends[$id] = $backend;
 903                         $delay = $backend->delaySave();
 904                 } else {
 905                         $backend = $this->allSessionBackends[$id];
 906                         $delay = $backend->delaySave();
 907                         if ( $info->wasPersisted() ) {
 908                                 $backend->persist();
 909                         }
 910                         if ( $info->wasRemembered() ) {
 911                                 $backend->setRememberUser( true );
 912                         }
 913                 }
 914
 915                 $request->setSessionId( $backend->getSessionId() );
 916                 $session = $backend->getSession( $request );
 917
 918                 if ( !$info->isIdSafe() ) {
 919                         $session->resetId();
 920                 }
 921
 922                 \ScopedCallback::consume( $delay );
 923                 return $session;
 924         }
 925
 926         /**
 927          * Deregister a SessionBackend
 928          * @private For use from \\MediaWiki\\Session\\SessionBackend only
 929          * @param SessionBackend $backend
 930          */
 931         public function deregisterSessionBackend( SessionBackend $backend ) {
 932                 $id = $backend->getId();
 933                 if ( !isset( $this->allSessionBackends[$id] ) || !isset( $this->allSessionIds[$id] ) ||
 934                         $this->allSessionBackends[$id] !== $backend ||
 935                         $this->allSessionIds[$id] !== $backend->getSessionId()
 936                 ) {
 937                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
 938                 }
 939
 940                 unset( $this->allSessionBackends[$id] );
 941                 // Explicitly do not unset $this->allSessionIds[$id]
 942         }
 943
 944         /**
 945          * Change a SessionBackend's ID
 946          * @private For use from \\MediaWiki\\Session\\SessionBackend only
 947          * @param SessionBackend $backend
 948          */
 949         public function changeBackendId( SessionBackend $backend ) {
 950                 $sessionId = $backend->getSessionId();
 951                 $oldId = (string)$sessionId;
 952                 if ( !isset( $this->allSessionBackends[$oldId] ) || !isset( $this->allSessionIds[$oldId] ) ||
 953                         $this->allSessionBackends[$oldId] !== $backend ||
 954                         $this->allSessionIds[$oldId] !== $sessionId
 955                 ) {
 956                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
 957                 }
 958
 959                 $newId = $this->generateSessionId();
 960
 961                 unset( $this->allSessionBackends[$oldId], $this->allSessionIds[$oldId] );
 962                 $sessionId->setId( $newId );
 963                 $this->allSessionBackends[$newId] = $backend;
 964                 $this->allSessionIds[$newId] = $sessionId;
 965         }
 966
 967         /**
 968          * Generate a new random session ID
 969          * @return string
 970          */
 971         public function generateSessionId() {
 972                 do {
 973                         $id = wfBaseConvert( \MWCryptRand::generateHex( 40 ), 16, 32, 32 );
 974                         $key = wfMemcKey( 'MWSession', $id );
 975                 } while ( isset( $this->allSessionIds[$id] ) || is_array( $this->store->get( $key ) ) );
 976                 return $id;
 977         }
 978
 979         /**
 980          * Call setters on a PHPSessionHandler
 981          * @private Use PhpSessionHandler::install()
 982          * @param PHPSessionHandler $handler
 983          */
 984         public function setupPHPSessionHandler( PHPSessionHandler $handler ) {
 985                 $handler->setManager( $this, $this->store, $this->logger );
 986         }
 987
 988         /**
 989          * Reset the internal caching for unit testing
 990          */
 991         public static function resetCache() {
 992                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 993                         // @codeCoverageIgnoreStart
 994                         throw new MWException( __METHOD__ . ' may only be called from unit tests!' );
 995                         // @codeCoverageIgnoreEnd
 996                 }
 997
 998                 self::$globalSession = null;
 999                 self::$globalSessionRequest = null;
1000         }
1001
1002         /**@}*/
1003
1004 }