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 Psr\Log\LogLevel;
  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                         $store->setLogger( $this->logger );
 172                 }
 173                 $this->store = $store instanceof CachedBagOStuff ? $store : new CachedBagOStuff( $store );
 174
 175                 register_shutdown_function( [ $this, 'shutdown' ] );
 176         }
 177
 178         public function setLogger( LoggerInterface $logger ) {
 179                 $this->logger = $logger;
 180         }
 181
 182         public function getSessionForRequest( WebRequest $request ) {
 183                 $info = $this->getSessionInfoForRequest( $request );
 184
 185                 if ( !$info ) {
 186                         $session = $this->getEmptySession( $request );
 187                 } else {
 188                         $session = $this->getSessionFromInfo( $info, $request );
 189                 }
 190                 return $session;
 191         }
 192
 193         public function getSessionById( $id, $create = false, WebRequest $request = null ) {
 194                 if ( !self::validateSessionId( $id ) ) {
 195                         throw new \InvalidArgumentException( 'Invalid session ID' );
 196                 }
 197                 if ( !$request ) {
 198                         $request = new FauxRequest;
 199                 }
 200
 201                 $session = null;
 202
 203                 // Test this here to provide a better log message for the common case
 204                 // of "no such ID"
 205                 $key = wfMemcKey( 'MWSession', $id );
 206                 if ( is_array( $this->store->get( $key ) ) ) {
 207                         $info = new SessionInfo( SessionInfo::MIN_PRIORITY, [ 'id' => $id, 'idIsSafe' => true ] );
 208                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 209                                 $session = $this->getSessionFromInfo( $info, $request );
 210                         }
 211                 }
 212
 213                 if ( $create && $session === null ) {
 214                         $ex = null;
 215                         try {
 216                                 $session = $this->getEmptySessionInternal( $request, $id );
 217                         } catch ( \Exception $ex ) {
 218                                 $this->logger->error( 'Failed to create empty session: {exception}',
 219                                         [
 220                                                 'method' => __METHOD__,
 221                                                 'exception' => $ex,
 222                                 ] );
 223                                 $session = null;
 224                         }
 225                 }
 226
 227                 return $session;
 228         }
 229
 230         public function getEmptySession( WebRequest $request = null ) {
 231                 return $this->getEmptySessionInternal( $request );
 232         }
 233
 234         /**
 235          * @see SessionManagerInterface::getEmptySession
 236          * @param WebRequest|null $request
 237          * @param string|null $id ID to force on the new session
 238          * @return Session
 239          */
 240         private function getEmptySessionInternal( WebRequest $request = null, $id = null ) {
 241                 if ( $id !== null ) {
 242                         if ( !self::validateSessionId( $id ) ) {
 243                                 throw new \InvalidArgumentException( 'Invalid session ID' );
 244                         }
 245
 246                         $key = wfMemcKey( 'MWSession', $id );
 247                         if ( is_array( $this->store->get( $key ) ) ) {
 248                                 throw new \InvalidArgumentException( 'Session ID already exists' );
 249                         }
 250                 }
 251                 if ( !$request ) {
 252                         $request = new FauxRequest;
 253                 }
 254
 255                 $infos = [];
 256                 foreach ( $this->getProviders() as $provider ) {
 257                         $info = $provider->newSessionInfo( $id );
 258                         if ( !$info ) {
 259                                 continue;
 260                         }
 261                         if ( $info->getProvider() !== $provider ) {
 262                                 throw new \UnexpectedValueException(
 263                                         "$provider returned an empty session info for a different provider: $info"
 264                                 );
 265                         }
 266                         if ( $id !== null && $info->getId() !== $id ) {
 267                                 throw new \UnexpectedValueException(
 268                                         "$provider returned empty session info with a wrong id: " .
 269                                                 $info->getId() . ' != ' . $id
 270                                 );
 271                         }
 272                         if ( !$info->isIdSafe() ) {
 273                                 throw new \UnexpectedValueException(
 274                                         "$provider returned empty session info with id flagged unsafe"
 275                                 );
 276                         }
 277                         $compare = $infos ? SessionInfo::compare( $infos[0], $info ) : -1;
 278                         if ( $compare > 0 ) {
 279                                 continue;
 280                         }
 281                         if ( $compare === 0 ) {
 282                                 $infos[] = $info;
 283                         } else {
 284                                 $infos = [ $info ];
 285                         }
 286                 }
 287
 288                 // Make sure there's exactly one
 289                 if ( count( $infos ) > 1 ) {
 290                         throw new \UnexpectedValueException(
 291                                 'Multiple empty sessions tied for top priority: ' . join( ', ', $infos )
 292                         );
 293                 } elseif ( count( $infos ) < 1 ) {
 294                         throw new \UnexpectedValueException( 'No provider could provide an empty session!' );
 295                 }
 296
 297                 return $this->getSessionFromInfo( $infos[0], $request );
 298         }
 299
 300         public function getVaryHeaders() {
 301                 if ( $this->varyHeaders === null ) {
 302                         $headers = [];
 303                         foreach ( $this->getProviders() as $provider ) {
 304                                 foreach ( $provider->getVaryHeaders() as $header => $options ) {
 305                                         if ( !isset( $headers[$header] ) ) {
 306                                                 $headers[$header] = [];
 307                                         }
 308                                         if ( is_array( $options ) ) {
 309                                                 $headers[$header] = array_unique( array_merge( $headers[$header], $options ) );
 310                                         }
 311                                 }
 312                         }
 313                         $this->varyHeaders = $headers;
 314                 }
 315                 return $this->varyHeaders;
 316         }
 317
 318         public function getVaryCookies() {
 319                 if ( $this->varyCookies === null ) {
 320                         $cookies = [];
 321                         foreach ( $this->getProviders() as $provider ) {
 322                                 $cookies = array_merge( $cookies, $provider->getVaryCookies() );
 323                         }
 324                         $this->varyCookies = array_values( array_unique( $cookies ) );
 325                 }
 326                 return $this->varyCookies;
 327         }
 328
 329         /**
 330          * Validate a session ID
 331          * @param string $id
 332          * @return bool
 333          */
 334         public static function validateSessionId( $id ) {
 335                 return is_string( $id ) && preg_match( '/^[a-zA-Z0-9_-]{32,}$/', $id );
 336         }
 337
 338         /**
 339          * @name Internal methods
 340          * @{
 341          */
 342
 343         /**
 344          * Auto-create the given user, if necessary
 345          * @private Don't call this yourself. Let Setup.php do it for you at the right time.
 346          * @note This more properly belongs in AuthManager, but we need it now.
 347          *  When AuthManager comes, this will be deprecated and will pass-through
 348          *  to the corresponding AuthManager method.
 349          * @param User $user User to auto-create
 350          * @return bool Success
 351          */
 352         public static function autoCreateUser( User $user ) {
 353                 global $wgAuth;
 354
 355                 $logger = self::singleton()->logger;
 356
 357                 // Much of this code is based on that in CentralAuth
 358
 359                 // Try the local user from the slave DB
 360                 $localId = User::idFromName( $user->getName() );
 361                 $flags = 0;
 362
 363                 // Fetch the user ID from the master, so that we don't try to create the user
 364                 // when they already exist, due to replication lag
 365                 // @codeCoverageIgnoreStart
 366                 if ( !$localId && wfGetLB()->getReaderIndex() != 0 ) {
 367                         $localId = User::idFromName( $user->getName(), User::READ_LATEST );
 368                         $flags = User::READ_LATEST;
 369                 }
 370                 // @codeCoverageIgnoreEnd
 371
 372                 if ( $localId ) {
 373                         // User exists after all.
 374                         $user->setId( $localId );
 375                         $user->loadFromId( $flags );
 376                         return false;
 377                 }
 378
 379                 // Denied by AuthPlugin? But ignore AuthPlugin itself.
 380                 if ( get_class( $wgAuth ) !== 'AuthPlugin' && !$wgAuth->autoCreate() ) {
 381                         $logger->debug( __METHOD__ . ': denied by AuthPlugin' );
 382                         $user->setId( 0 );
 383                         $user->loadFromId();
 384                         return false;
 385                 }
 386
 387                 // Wiki is read-only?
 388                 if ( wfReadOnly() ) {
 389                         $logger->debug( __METHOD__ . ': denied by wfReadOnly()' );
 390                         $user->setId( 0 );
 391                         $user->loadFromId();
 392                         return false;
 393                 }
 394
 395                 $userName = $user->getName();
 396
 397                 // Check the session, if we tried to create this user already there's
 398                 // no point in retrying.
 399                 $session = self::getGlobalSession();
 400                 $reason = $session->get( 'MWSession::AutoCreateBlacklist' );
 401                 if ( $reason ) {
 402                         $logger->debug( __METHOD__ . ": blacklisted in session ($reason)" );
 403                         $user->setId( 0 );
 404                         $user->loadFromId();
 405                         return false;
 406                 }
 407
 408                 // Is the IP user able to create accounts?
 409                 $anon = new User;
 410                 if ( !$anon->isAllowedAny( 'createaccount', 'autocreateaccount' )
 411                         || $anon->isBlockedFromCreateAccount()
 412                 ) {
 413                         // Blacklist the user to avoid repeated DB queries subsequently
 414                         $logger->debug( __METHOD__ . ': user is blocked from this wiki, blacklisting' );
 415                         $session->set( 'MWSession::AutoCreateBlacklist', 'blocked', 600 );
 416                         $session->persist();
 417                         $user->setId( 0 );
 418                         $user->loadFromId();
 419                         return false;
 420                 }
 421
 422                 // Check for validity of username
 423                 if ( !User::isCreatableName( $userName ) ) {
 424                         $logger->debug( __METHOD__ . ': Invalid username, blacklisting' );
 425                         $session->set( 'MWSession::AutoCreateBlacklist', 'invalid username', 600 );
 426                         $session->persist();
 427                         $user->setId( 0 );
 428                         $user->loadFromId();
 429                         return false;
 430                 }
 431
 432                 // Give other extensions a chance to stop auto creation.
 433                 $user->loadDefaults( $userName );
 434                 $abortMessage = '';
 435                 if ( !\Hooks::run( 'AbortAutoAccount', [ $user, &$abortMessage ] ) ) {
 436                         // In this case we have no way to return the message to the user,
 437                         // but we can log it.
 438                         $logger->debug( __METHOD__ . ": denied by hook: $abortMessage" );
 439                         $session->set( 'MWSession::AutoCreateBlacklist', "hook aborted: $abortMessage", 600 );
 440                         $session->persist();
 441                         $user->setId( 0 );
 442                         $user->loadFromId();
 443                         return false;
 444                 }
 445
 446                 // Make sure the name has not been changed
 447                 if ( $user->getName() !== $userName ) {
 448                         $user->setId( 0 );
 449                         $user->loadFromId();
 450                         throw new \UnexpectedValueException(
 451                                 'AbortAutoAccount hook tried to change the user name'
 452                         );
 453                 }
 454
 455                 // Ignore warnings about master connections/writes...hard to avoid here
 456                 \Profiler::instance()->getTransactionProfiler()->resetExpectations();
 457
 458                 $cache = \ObjectCache::getLocalClusterInstance();
 459                 $backoffKey = wfMemcKey( 'MWSession', 'autocreate-failed', md5( $userName ) );
 460                 if ( $cache->get( $backoffKey ) ) {
 461                         $logger->debug( __METHOD__ . ': denied by prior creation attempt failures' );
 462                         $user->setId( 0 );
 463                         $user->loadFromId();
 464                         return false;
 465                 }
 466
 467                 // Checks passed, create the user...
 468                 $from = isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : 'CLI';
 469                 $logger->info( __METHOD__ . ': creating new user ({username}) - from: {url}',
 470                         [
 471                                 'username' => $userName,
 472                                 'url' => $from,
 473                 ] );
 474
 475                 try {
 476                         // Insert the user into the local DB master
 477                         $status = $user->addToDatabase();
 478                         if ( !$status->isOK() ) {
 479                                 // @codeCoverageIgnoreStart
 480                                 $logger->error( __METHOD__ . ': failed with message ' . $status->getWikiText(),
 481                                         [
 482                                                 'username' => $userName,
 483                                 ] );
 484                                 $user->setId( 0 );
 485                                 $user->loadFromId();
 486                                 return false;
 487                                 // @codeCoverageIgnoreEnd
 488                         }
 489                 } catch ( \Exception $ex ) {
 490                         // @codeCoverageIgnoreStart
 491                         $logger->error( __METHOD__ . ': failed with exception {exception}', [
 492                                 'exception' => $ex,
 493                                 'username' => $userName,
 494                         ] );
 495                         // Do not keep throwing errors for a while
 496                         $cache->set( $backoffKey, 1, 600 );
 497                         // Bubble up error; which should normally trigger DB rollbacks
 498                         throw $ex;
 499                         // @codeCoverageIgnoreEnd
 500                 }
 501
 502                 # Notify AuthPlugin
 503                 $tmpUser = $user;
 504                 $wgAuth->initUser( $tmpUser, true );
 505                 if ( $tmpUser !== $user ) {
 506                         $logger->warning( __METHOD__ . ': ' .
 507                                 get_class( $wgAuth ) . '::initUser() replaced the user object' );
 508                 }
 509
 510                 # Notify hooks (e.g. Newuserlog)
 511                 \Hooks::run( 'AuthPluginAutoCreate', [ $user ] );
 512                 \Hooks::run( 'LocalUserCreated', [ $user, true ] );
 513
 514                 $user->saveSettings();
 515
 516                 # Update user count
 517                 \DeferredUpdates::addUpdate( new \SiteStatsUpdate( 0, 0, 0, 0, 1 ) );
 518
 519                 # Watch user's userpage and talk page
 520                 $user->addWatch( $user->getUserPage(), \WatchedItem::IGNORE_USER_RIGHTS );
 521
 522                 return true;
 523         }
 524
 525         /**
 526          * Prevent future sessions for the user
 527          *
 528          * The intention is that the named account will never again be usable for
 529          * normal login (i.e. there is no way to undo the prevention of access).
 530          *
 531          * @private For use from \\User::newSystemUser only
 532          * @param string $username
 533          */
 534         public function preventSessionsForUser( $username ) {
 535                 $this->preventUsers[$username] = true;
 536
 537                 // Instruct the session providers to kill any other sessions too.
 538                 foreach ( $this->getProviders() as $provider ) {
 539                         $provider->preventSessionsForUser( $username );
 540                 }
 541         }
 542
 543         /**
 544          * Test if a user is prevented
 545          * @private For use from SessionBackend only
 546          * @param string $username
 547          * @return bool
 548          */
 549         public function isUserSessionPrevented( $username ) {
 550                 return !empty( $this->preventUsers[$username] );
 551         }
 552
 553         /**
 554          * Get the available SessionProviders
 555          * @return SessionProvider[]
 556          */
 557         protected function getProviders() {
 558                 if ( $this->sessionProviders === null ) {
 559                         $this->sessionProviders = [];
 560                         foreach ( $this->config->get( 'SessionProviders' ) as $spec ) {
 561                                 $provider = \ObjectFactory::getObjectFromSpec( $spec );
 562                                 $provider->setLogger( $this->logger );
 563                                 $provider->setConfig( $this->config );
 564                                 $provider->setManager( $this );
 565                                 if ( isset( $this->sessionProviders[(string)$provider] ) ) {
 566                                         throw new \UnexpectedValueException( "Duplicate provider name \"$provider\"" );
 567                                 }
 568                                 $this->sessionProviders[(string)$provider] = $provider;
 569                         }
 570                 }
 571                 return $this->sessionProviders;
 572         }
 573
 574         /**
 575          * Get a session provider by name
 576          *
 577          * Generally, this will only be used by internal implementation of some
 578          * special session-providing mechanism. General purpose code, if it needs
 579          * to access a SessionProvider at all, will use Session::getProvider().
 580          *
 581          * @param string $name
 582          * @return SessionProvider|null
 583          */
 584         public function getProvider( $name ) {
 585                 $providers = $this->getProviders();
 586                 return isset( $providers[$name] ) ? $providers[$name] : null;
 587         }
 588
 589         /**
 590          * Save all active sessions on shutdown
 591          * @private For internal use with register_shutdown_function()
 592          */
 593         public function shutdown() {
 594                 if ( $this->allSessionBackends ) {
 595                         $this->logger->debug( 'Saving all sessions on shutdown' );
 596                         if ( session_id() !== '' ) {
 597                                 // @codeCoverageIgnoreStart
 598                                 session_write_close();
 599                         }
 600                         // @codeCoverageIgnoreEnd
 601                         foreach ( $this->allSessionBackends as $backend ) {
 602                                 $backend->save( true );
 603                         }
 604                 }
 605         }
 606
 607         /**
 608          * Fetch the SessionInfo(s) for a request
 609          * @param WebRequest $request
 610          * @return SessionInfo|null
 611          */
 612         private function getSessionInfoForRequest( WebRequest $request ) {
 613                 // Call all providers to fetch "the" session
 614                 $infos = [];
 615                 foreach ( $this->getProviders() as $provider ) {
 616                         $info = $provider->provideSessionInfo( $request );
 617                         if ( !$info ) {
 618                                 continue;
 619                         }
 620                         if ( $info->getProvider() !== $provider ) {
 621                                 throw new \UnexpectedValueException(
 622                                         "$provider returned session info for a different provider: $info"
 623                                 );
 624                         }
 625                         $infos[] = $info;
 626                 }
 627
 628                 // Sort the SessionInfos. Then find the first one that can be
 629                 // successfully loaded, and then all the ones after it with the same
 630                 // priority.
 631                 usort( $infos, 'MediaWiki\\Session\\SessionInfo::compare' );
 632                 $retInfos = [];
 633                 while ( $infos ) {
 634                         $info = array_pop( $infos );
 635                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 636                                 $retInfos[] = $info;
 637                                 while ( $infos ) {
 638                                         $info = array_pop( $infos );
 639                                         if ( SessionInfo::compare( $retInfos[0], $info ) ) {
 640                                                 // We hit a lower priority, stop checking.
 641                                                 break;
 642                                         }
 643                                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 644                                                 // This is going to error out below, but we want to
 645                                                 // provide a complete list.
 646                                                 $retInfos[] = $info;
 647                                         }
 648                                 }
 649                         }
 650                 }
 651
 652                 if ( count( $retInfos ) > 1 ) {
 653                         $ex = new \OverflowException(
 654                                 'Multiple sessions for this request tied for top priority: ' . join( ', ', $retInfos )
 655                         );
 656                         $ex->sessionInfos = $retInfos;
 657                         throw $ex;
 658                 }
 659
 660                 return $retInfos ? $retInfos[0] : null;
 661         }
 662
 663         /**
 664          * Load and verify the session info against the store
 665          *
 666          * @param SessionInfo &$info Will likely be replaced with an updated SessionInfo instance
 667          * @param WebRequest $request
 668          * @return bool Whether the session info matches the stored data (if any)
 669          */
 670         private function loadSessionInfoFromStore( SessionInfo &$info, WebRequest $request ) {
 671                 $key = wfMemcKey( 'MWSession', $info->getId() );
 672                 $blob = $this->store->get( $key );
 673
 674                 $newParams = [];
 675
 676                 if ( $blob !== false ) {
 677                         // Sanity check: blob must be an array, if it's saved at all
 678                         if ( !is_array( $blob ) ) {
 679                                 $this->logger->warning( 'Session "{session}": Bad data', [
 680                                         'session' => $info,
 681                                 ] );
 682                                 $this->store->delete( $key );
 683                                 return false;
 684                         }
 685
 686                         // Sanity check: blob has data and metadata arrays
 687                         if ( !isset( $blob['data'] ) || !is_array( $blob['data'] ) ||
 688                                 !isset( $blob['metadata'] ) || !is_array( $blob['metadata'] )
 689                         ) {
 690                                 $this->logger->warning( 'Session "{session}": Bad data structure', [
 691                                         'session' => $info,
 692                                 ] );
 693                                 $this->store->delete( $key );
 694                                 return false;
 695                         }
 696
 697                         $data = $blob['data'];
 698                         $metadata = $blob['metadata'];
 699
 700                         // Sanity check: metadata must be an array and must contain certain
 701                         // keys, if it's saved at all
 702                         if ( !array_key_exists( 'userId', $metadata ) ||
 703                                 !array_key_exists( 'userName', $metadata ) ||
 704                                 !array_key_exists( 'userToken', $metadata ) ||
 705                                 !array_key_exists( 'provider', $metadata )
 706                         ) {
 707                                 $this->logger->warning( 'Session "{session}": Bad metadata', [
 708                                         'session' => $info,
 709                                 ] );
 710                                 $this->store->delete( $key );
 711                                 return false;
 712                         }
 713
 714                         // First, load the provider from metadata, or validate it against the metadata.
 715                         $provider = $info->getProvider();
 716                         if ( $provider === null ) {
 717                                 $newParams['provider'] = $provider = $this->getProvider( $metadata['provider'] );
 718                                 if ( !$provider ) {
 719                                         $this->logger->warning(
 720                                                 'Session "{session}": Unknown provider ' . $metadata['provider'],
 721                                                 [
 722                                                         'session' => $info,
 723                                                 ]
 724                                         );
 725                                         $this->store->delete( $key );
 726                                         return false;
 727                                 }
 728                         } elseif ( $metadata['provider'] !== (string)$provider ) {
 729                                 $this->logger->warning( 'Session "{session}": Wrong provider ' .
 730                                         $metadata['provider'] . ' !== ' . $provider,
 731                                         [
 732                                                 'session' => $info,
 733                                 ] );
 734                                 return false;
 735                         }
 736
 737                         // Load provider metadata from metadata, or validate it against the metadata
 738                         $providerMetadata = $info->getProviderMetadata();
 739                         if ( isset( $metadata['providerMetadata'] ) ) {
 740                                 if ( $providerMetadata === null ) {
 741                                         $newParams['metadata'] = $metadata['providerMetadata'];
 742                                 } else {
 743                                         try {
 744                                                 $newProviderMetadata = $provider->mergeMetadata(
 745                                                         $metadata['providerMetadata'], $providerMetadata
 746                                                 );
 747                                                 if ( $newProviderMetadata !== $providerMetadata ) {
 748                                                         $newParams['metadata'] = $newProviderMetadata;
 749                                                 }
 750                                         } catch ( MetadataMergeException $ex ) {
 751                                                 $this->logger->warning(
 752                                                         'Session "{session}": Metadata merge failed: {exception}',
 753                                                         [
 754                                                                 'session' => $info,
 755                                                                 'exception' => $ex,
 756                                                         ] + $ex->getContext()
 757                                                 );
 758                                                 return false;
 759                                         }
 760                                 }
 761                         }
 762
 763                         // Next, load the user from metadata, or validate it against the metadata.
 764                         $userInfo = $info->getUserInfo();
 765                         if ( !$userInfo ) {
 766                                 // For loading, id is preferred to name.
 767                                 try {
 768                                         if ( $metadata['userId'] ) {
 769                                                 $userInfo = UserInfo::newFromId( $metadata['userId'] );
 770                                         } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 771                                                 $userInfo = UserInfo::newFromName( $metadata['userName'] );
 772                                         } else {
 773                                                 $userInfo = UserInfo::newAnonymous();
 774                                         }
 775                                 } catch ( \InvalidArgumentException $ex ) {
 776                                         $this->logger->error( 'Session "{session}": {exception}', [
 777                                                 'session' => $info,
 778                                                 'exception' => $ex,
 779                                         ] );
 780                                         return false;
 781                                 }
 782                                 $newParams['userInfo'] = $userInfo;
 783                         } else {
 784                                 // User validation passes if user ID matches, or if there
 785                                 // is no saved ID and the names match.
 786                                 if ( $metadata['userId'] ) {
 787                                         if ( $metadata['userId'] !== $userInfo->getId() ) {
 788                                                 $this->logger->warning(
 789                                                         'Session "{session}": User ID mismatch, {uid_a} !== {uid_b}',
 790                                                         [
 791                                                                 'session' => $info,
 792                                                                 'uid_a' => $metadata['userId'],
 793                                                                 'uid_b' => $userInfo->getId(),
 794                                                 ] );
 795                                                 return false;
 796                                         }
 797
 798                                         // If the user was renamed, probably best to fail here.
 799                                         if ( $metadata['userName'] !== null &&
 800                                                 $userInfo->getName() !== $metadata['userName']
 801                                         ) {
 802                                                 $this->logger->warning(
 803                                                         'Session "{session}": User ID matched but name didn\'t (rename?), {uname_a} !== {uname_b}',
 804                                                         [
 805                                                                 'session' => $info,
 806                                                                 'uname_a' => $metadata['userName'],
 807                                                                 'uname_b' => $userInfo->getName(),
 808                                                 ] );
 809                                                 return false;
 810                                         }
 811
 812                                 } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 813                                         if ( $metadata['userName'] !== $userInfo->getName() ) {
 814                                                 $this->logger->warning(
 815                                                         'Session "{session}": User name mismatch, {uname_a} !== {uname_b}',
 816                                                         [
 817                                                                 'session' => $info,
 818                                                                 'uname_a' => $metadata['userName'],
 819                                                                 'uname_b' => $userInfo->getName(),
 820                                                 ] );
 821                                                 return false;
 822                                         }
 823                                 } elseif ( !$userInfo->isAnon() ) {
 824                                         // Metadata specifies an anonymous user, but the passed-in
 825                                         // user isn't anonymous.
 826                                         $this->logger->warning(
 827                                                 'Session "{session}": Metadata has an anonymous user, but a non-anon user was provided',
 828                                                 [
 829                                                         'session' => $info,
 830                                         ] );
 831                                         return false;
 832                                 }
 833                         }
 834
 835                         // And if we have a token in the metadata, it must match the loaded/provided user.
 836                         if ( $metadata['userToken'] !== null &&
 837                                 $userInfo->getToken() !== $metadata['userToken']
 838                         ) {
 839                                 $this->logger->warning( 'Session "{session}": User token mismatch', [
 840                                         'session' => $info,
 841                                 ] );
 842                                 return false;
 843                         }
 844                         if ( !$userInfo->isVerified() ) {
 845                                 $newParams['userInfo'] = $userInfo->verified();
 846                         }
 847
 848                         if ( !empty( $metadata['remember'] ) && !$info->wasRemembered() ) {
 849                                 $newParams['remembered'] = true;
 850                         }
 851                         if ( !empty( $metadata['forceHTTPS'] ) && !$info->forceHTTPS() ) {
 852                                 $newParams['forceHTTPS'] = true;
 853                         }
 854                         if ( !empty( $metadata['persisted'] ) && !$info->wasPersisted() ) {
 855                                 $newParams['persisted'] = true;
 856                         }
 857
 858                         if ( !$info->isIdSafe() ) {
 859                                 $newParams['idIsSafe'] = true;
 860                         }
 861                 } else {
 862                         // No metadata, so we can't load the provider if one wasn't given.
 863                         if ( $info->getProvider() === null ) {
 864                                 $this->logger->warning(
 865                                         'Session "{session}": Null provider and no metadata',
 866                                         [
 867                                                 'session' => $info,
 868                                 ] );
 869                                 return false;
 870                         }
 871
 872                         // If no user was provided and no metadata, it must be anon.
 873                         if ( !$info->getUserInfo() ) {
 874                                 if ( $info->getProvider()->canChangeUser() ) {
 875                                         $newParams['userInfo'] = UserInfo::newAnonymous();
 876                                 } else {
 877                                         $this->logger->info(
 878                                                 'Session "{session}": No user provided and provider cannot set user',
 879                                                 [
 880                                                         'session' => $info,
 881                                         ] );
 882                                         return false;
 883                                 }
 884                         } elseif ( !$info->getUserInfo()->isVerified() ) {
 885                                 $this->logger->warning(
 886                                         'Session "{session}": Unverified user provided and no metadata to auth it',
 887                                         [
 888                                                 'session' => $info,
 889                                 ] );
 890                                 return false;
 891                         }
 892
 893                         $data = false;
 894                         $metadata = false;
 895
 896                         if ( !$info->getProvider()->persistsSessionId() && !$info->isIdSafe() ) {
 897                                 // The ID doesn't come from the user, so it should be safe
 898                                 // (and if not, nothing we can do about it anyway)
 899                                 $newParams['idIsSafe'] = true;
 900                         }
 901                 }
 902
 903                 // Construct the replacement SessionInfo, if necessary
 904                 if ( $newParams ) {
 905                         $newParams['copyFrom'] = $info;
 906                         $info = new SessionInfo( $info->getPriority(), $newParams );
 907                 }
 908
 909                 // Allow the provider to check the loaded SessionInfo
 910                 $providerMetadata = $info->getProviderMetadata();
 911                 if ( !$info->getProvider()->refreshSessionInfo( $info, $request, $providerMetadata ) ) {
 912                         return false;
 913                 }
 914                 if ( $providerMetadata !== $info->getProviderMetadata() ) {
 915                         $info = new SessionInfo( $info->getPriority(), [
 916                                 'metadata' => $providerMetadata,
 917                                 'copyFrom' => $info,
 918                         ] );
 919                 }
 920
 921                 // Give hooks a chance to abort. Combined with the SessionMetadata
 922                 // hook, this can allow for tying a session to an IP address or the
 923                 // like.
 924                 $reason = 'Hook aborted';
 925                 if ( !\Hooks::run(
 926                         'SessionCheckInfo',
 927                         [ &$reason, $info, $request, $metadata, $data ]
 928                 ) ) {
 929                         $this->logger->warning( 'Session "{session}": ' . $reason, [
 930                                 'session' => $info,
 931                         ] );
 932                         return false;
 933                 }
 934
 935                 return true;
 936         }
 937
 938         /**
 939          * Create a session corresponding to the passed SessionInfo
 940          * @private For use by a SessionProvider that needs to specially create its
 941          *  own session.
 942          * @param SessionInfo $info
 943          * @param WebRequest $request
 944          * @return Session
 945          */
 946         public function getSessionFromInfo( SessionInfo $info, WebRequest $request ) {
 947                 $id = $info->getId();
 948
 949                 if ( !isset( $this->allSessionBackends[$id] ) ) {
 950                         if ( !isset( $this->allSessionIds[$id] ) ) {
 951                                 $this->allSessionIds[$id] = new SessionId( $id );
 952                         }
 953                         $backend = new SessionBackend(
 954                                 $this->allSessionIds[$id],
 955                                 $info,
 956                                 $this->store,
 957                                 $this->logger,
 958                                 $this->config->get( 'ObjectCacheSessionExpiry' )
 959                         );
 960                         $this->allSessionBackends[$id] = $backend;
 961                         $delay = $backend->delaySave();
 962                 } else {
 963                         $backend = $this->allSessionBackends[$id];
 964                         $delay = $backend->delaySave();
 965                         if ( $info->wasPersisted() ) {
 966                                 $backend->persist();
 967                         }
 968                         if ( $info->wasRemembered() ) {
 969                                 $backend->setRememberUser( true );
 970                         }
 971                 }
 972
 973                 $request->setSessionId( $backend->getSessionId() );
 974                 $session = $backend->getSession( $request );
 975
 976                 if ( !$info->isIdSafe() ) {
 977                         $session->resetId();
 978                 }
 979
 980                 \ScopedCallback::consume( $delay );
 981                 return $session;
 982         }
 983
 984         /**
 985          * Deregister a SessionBackend
 986          * @private For use from \\MediaWiki\\Session\\SessionBackend only
 987          * @param SessionBackend $backend
 988          */
 989         public function deregisterSessionBackend( SessionBackend $backend ) {
 990                 $id = $backend->getId();
 991                 if ( !isset( $this->allSessionBackends[$id] ) || !isset( $this->allSessionIds[$id] ) ||
 992                         $this->allSessionBackends[$id] !== $backend ||
 993                         $this->allSessionIds[$id] !== $backend->getSessionId()
 994                 ) {
 995                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
 996                 }
 997
 998                 unset( $this->allSessionBackends[$id] );
 999                 // Explicitly do not unset $this->allSessionIds[$id]
1000         }
1001
1002         /**
1003          * Change a SessionBackend's ID
1004          * @private For use from \\MediaWiki\\Session\\SessionBackend only
1005          * @param SessionBackend $backend
1006          */
1007         public function changeBackendId( SessionBackend $backend ) {
1008                 $sessionId = $backend->getSessionId();
1009                 $oldId = (string)$sessionId;
1010                 if ( !isset( $this->allSessionBackends[$oldId] ) || !isset( $this->allSessionIds[$oldId] ) ||
1011                         $this->allSessionBackends[$oldId] !== $backend ||
1012                         $this->allSessionIds[$oldId] !== $sessionId
1013                 ) {
1014                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
1015                 }
1016
1017                 $newId = $this->generateSessionId();
1018
1019                 unset( $this->allSessionBackends[$oldId], $this->allSessionIds[$oldId] );
1020                 $sessionId->setId( $newId );
1021                 $this->allSessionBackends[$newId] = $backend;
1022                 $this->allSessionIds[$newId] = $sessionId;
1023         }
1024
1025         /**
1026          * Generate a new random session ID
1027          * @return string
1028          */
1029         public function generateSessionId() {
1030                 do {
1031                         $id = wfBaseConvert( \MWCryptRand::generateHex( 40 ), 16, 32, 32 );
1032                         $key = wfMemcKey( 'MWSession', $id );
1033                 } while ( isset( $this->allSessionIds[$id] ) || is_array( $this->store->get( $key ) ) );
1034                 return $id;
1035         }
1036
1037         /**
1038          * Call setters on a PHPSessionHandler
1039          * @private Use PhpSessionHandler::install()
1040          * @param PHPSessionHandler $handler
1041          */
1042         public function setupPHPSessionHandler( PHPSessionHandler $handler ) {
1043                 $handler->setManager( $this, $this->store, $this->logger );
1044         }
1045
1046         /**
1047          * Reset the internal caching for unit testing
1048          */
1049         public static function resetCache() {
1050                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
1051                         // @codeCoverageIgnoreStart
1052                         throw new MWException( __METHOD__ . ' may only be called from unit tests!' );
1053                         // @codeCoverageIgnoreEnd
1054                 }
1055
1056                 self::$globalSession = null;
1057                 self::$globalSessionRequest = null;
1058         }
1059
1060         /**
1061          * Do a sanity check to make sure the session is not used from many different IP addresses
1062          * and store some data for later sanity checks.
1063          * FIXME remove this once SessionManager is considered stable
1064          * @private For use in Setup.php only
1065          * @param Session $session Defaults to the global session.
1066          */
1067         public function checkIpLimits( Session $session = null ) {
1068                 $session = $session ?: self::getGlobalSession();
1069
1070                 try {
1071                         $ip = $session->getRequest()->getIP();
1072                 } catch ( \MWException $e ) {
1073                         return;
1074                 }
1075                 if ( $ip === '127.0.0.1' || \IP::isConfiguredProxy( $ip ) ) {
1076                         return;
1077                 }
1078                 $now = time();
1079
1080                 // Record (and possibly log) that the IP is using the current session.
1081                 // Don't touch the stored data unless we are adding a new IP or re-adding an expired one.
1082                 // This is slightly inaccurate (when an existing IP is seen again, the expiry is not
1083                 // extended) but that shouldn't make much difference and limits the session write frequency
1084                 // to # of IPs / $wgSuspiciousIpExpiry.
1085                 $data = $session->get( 'SessionManager-ip', [] );
1086                 if (
1087                         !isset( $data[$ip] )
1088                         || $data[$ip] < $now
1089                 ) {
1090                         $data[$ip] = time() + $this->config->get( 'SuspiciousIpExpiry' );
1091                         foreach ( $data as $key => $expires ) {
1092                                 if ( $expires < $now ) {
1093                                         unset( $data[$key] );
1094                                 }
1095                         }
1096                         $session->set( 'SessionManager-ip', $data );
1097
1098                         $logger = \MediaWiki\Logger\LoggerFactory::getInstance( 'session-ip' );
1099                         $logLevel = count( $data ) >= $this->config->get( 'SuspiciousIpPerSessionLimit' )
1100                                 ? LogLevel::WARNING : ( count( $data ) === 1 ? LogLevel::DEBUG : LogLevel::INFO );
1101                         $logger->log(
1102                                 $logLevel,
1103                                 'Same session used from {count} IPs',
1104                                 [
1105                                         'count' => count( $data ),
1106                                         'ips' => $data,
1107                                         'session' => $session->getId(),
1108                                         'user' => $session->getUser()->getName(),
1109                                         'persistent' => $session->isPersistent(),
1110                                 ]
1111                         );
1112                 }
1113
1114                 // Now do the same thing globally for the current user.
1115                 // We are using the object cache and assume it is shared between all wikis of a farm,
1116                 // and further assume that the same name belongs to the same user on all wikis. (It's either
1117                 // that or a central ID lookup which would mean an extra SQL query on every request.)
1118                 if ( $session->getUser()->isLoggedIn() ) {
1119                         $userKey = 'SessionManager-ip:' . md5( $session->getUser()->getName() );
1120                         $data = $this->store->get( $userKey ) ?: [];
1121                         if (
1122                                 !isset( $data[$ip] )
1123                                 || $data[$ip] < $now
1124                         ) {
1125                                 $data[$ip] = time() + $this->config->get( 'SuspiciousIpExpiry' );
1126                                 foreach ( $data as $key => $expires ) {
1127                                         if ( $expires < $now ) {
1128                                                 unset( $data[$key] );
1129                                         }
1130                                 }
1131                                 $this->store->set( $userKey, $data, $this->config->get( 'SuspiciousIpExpiry' ) );
1132                                 $logger = \MediaWiki\Logger\LoggerFactory::getInstance( 'session-ip' );
1133                                 $logLevel = count( $data ) >= $this->config->get( 'SuspiciousIpPerUserLimit' )
1134                                         ? LogLevel::WARNING : ( count( $data ) === 1 ? LogLevel::DEBUG : LogLevel::INFO );
1135                                 $logger->log(
1136                                         $logLevel,
1137                                         'Same user had sessions from {count} IPs',
1138                                         [
1139                                                 'count' => count( $data ),
1140                                                 'ips' => $data,
1141                                                 'session' => $session->getId(),
1142                                                 'user' => $session->getUser()->getName(),
1143                                                 'persistent' => $session->isPersistent(),
1144                                         ]
1145                                 );
1146                         }
1147                 }
1148         }
1149
1150         /**@}*/
1151
1152 }