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                                 // double-check for a race condition (T70012)
 481                                 $id = User::idFromName( $user->getName(), User::READ_LATEST );
 482                                 if ( $id ) {
 483                                         $logger->info( __METHOD__ . ': tried to autocreate existing user',
 484                                                 [
 485                                                         'username' => $userName,
 486                                                 ] );
 487                                 } else {
 488                                         $logger->error( __METHOD__ . ': failed with message ' . $status->getWikiText(),
 489                                                 [
 490                                                         'username' => $userName,
 491                                                 ] );
 492                                 }
 493                                 $user->setId( $id );
 494                                 $user->loadFromId( User::READ_LATEST );
 495                                 return false;
 496                                 // @codeCoverageIgnoreEnd
 497                         }
 498                 } catch ( \Exception $ex ) {
 499                         // @codeCoverageIgnoreStart
 500                         $logger->error( __METHOD__ . ': failed with exception {exception}', [
 501                                 'exception' => $ex,
 502                                 'username' => $userName,
 503                         ] );
 504                         // Do not keep throwing errors for a while
 505                         $cache->set( $backoffKey, 1, 600 );
 506                         // Bubble up error; which should normally trigger DB rollbacks
 507                         throw $ex;
 508                         // @codeCoverageIgnoreEnd
 509                 }
 510
 511                 # Notify AuthPlugin
 512                 $tmpUser = $user;
 513                 $wgAuth->initUser( $tmpUser, true );
 514                 if ( $tmpUser !== $user ) {
 515                         $logger->warning( __METHOD__ . ': ' .
 516                                 get_class( $wgAuth ) . '::initUser() replaced the user object' );
 517                 }
 518
 519                 # Notify hooks (e.g. Newuserlog)
 520                 \Hooks::run( 'AuthPluginAutoCreate', [ $user ] );
 521                 \Hooks::run( 'LocalUserCreated', [ $user, true ] );
 522
 523                 $user->saveSettings();
 524
 525                 # Update user count
 526                 \DeferredUpdates::addUpdate( new \SiteStatsUpdate( 0, 0, 0, 0, 1 ) );
 527
 528                 # Watch user's userpage and talk page
 529                 $user->addWatch( $user->getUserPage(), \WatchedItem::IGNORE_USER_RIGHTS );
 530
 531                 return true;
 532         }
 533
 534         /**
 535          * Prevent future sessions for the user
 536          *
 537          * The intention is that the named account will never again be usable for
 538          * normal login (i.e. there is no way to undo the prevention of access).
 539          *
 540          * @private For use from \\User::newSystemUser only
 541          * @param string $username
 542          */
 543         public function preventSessionsForUser( $username ) {
 544                 $this->preventUsers[$username] = true;
 545
 546                 // Instruct the session providers to kill any other sessions too.
 547                 foreach ( $this->getProviders() as $provider ) {
 548                         $provider->preventSessionsForUser( $username );
 549                 }
 550         }
 551
 552         /**
 553          * Test if a user is prevented
 554          * @private For use from SessionBackend only
 555          * @param string $username
 556          * @return bool
 557          */
 558         public function isUserSessionPrevented( $username ) {
 559                 return !empty( $this->preventUsers[$username] );
 560         }
 561
 562         /**
 563          * Get the available SessionProviders
 564          * @return SessionProvider[]
 565          */
 566         protected function getProviders() {
 567                 if ( $this->sessionProviders === null ) {
 568                         $this->sessionProviders = [];
 569                         foreach ( $this->config->get( 'SessionProviders' ) as $spec ) {
 570                                 $provider = \ObjectFactory::getObjectFromSpec( $spec );
 571                                 $provider->setLogger( $this->logger );
 572                                 $provider->setConfig( $this->config );
 573                                 $provider->setManager( $this );
 574                                 if ( isset( $this->sessionProviders[(string)$provider] ) ) {
 575                                         throw new \UnexpectedValueException( "Duplicate provider name \"$provider\"" );
 576                                 }
 577                                 $this->sessionProviders[(string)$provider] = $provider;
 578                         }
 579                 }
 580                 return $this->sessionProviders;
 581         }
 582
 583         /**
 584          * Get a session provider by name
 585          *
 586          * Generally, this will only be used by internal implementation of some
 587          * special session-providing mechanism. General purpose code, if it needs
 588          * to access a SessionProvider at all, will use Session::getProvider().
 589          *
 590          * @param string $name
 591          * @return SessionProvider|null
 592          */
 593         public function getProvider( $name ) {
 594                 $providers = $this->getProviders();
 595                 return isset( $providers[$name] ) ? $providers[$name] : null;
 596         }
 597
 598         /**
 599          * Save all active sessions on shutdown
 600          * @private For internal use with register_shutdown_function()
 601          */
 602         public function shutdown() {
 603                 if ( $this->allSessionBackends ) {
 604                         $this->logger->debug( 'Saving all sessions on shutdown' );
 605                         if ( session_id() !== '' ) {
 606                                 // @codeCoverageIgnoreStart
 607                                 session_write_close();
 608                         }
 609                         // @codeCoverageIgnoreEnd
 610                         foreach ( $this->allSessionBackends as $backend ) {
 611                                 $backend->save( true );
 612                         }
 613                 }
 614         }
 615
 616         /**
 617          * Fetch the SessionInfo(s) for a request
 618          * @param WebRequest $request
 619          * @return SessionInfo|null
 620          */
 621         private function getSessionInfoForRequest( WebRequest $request ) {
 622                 // Call all providers to fetch "the" session
 623                 $infos = [];
 624                 foreach ( $this->getProviders() as $provider ) {
 625                         $info = $provider->provideSessionInfo( $request );
 626                         if ( !$info ) {
 627                                 continue;
 628                         }
 629                         if ( $info->getProvider() !== $provider ) {
 630                                 throw new \UnexpectedValueException(
 631                                         "$provider returned session info for a different provider: $info"
 632                                 );
 633                         }
 634                         $infos[] = $info;
 635                 }
 636
 637                 // Sort the SessionInfos. Then find the first one that can be
 638                 // successfully loaded, and then all the ones after it with the same
 639                 // priority.
 640                 usort( $infos, 'MediaWiki\\Session\\SessionInfo::compare' );
 641                 $retInfos = [];
 642                 while ( $infos ) {
 643                         $info = array_pop( $infos );
 644                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 645                                 $retInfos[] = $info;
 646                                 while ( $infos ) {
 647                                         $info = array_pop( $infos );
 648                                         if ( SessionInfo::compare( $retInfos[0], $info ) ) {
 649                                                 // We hit a lower priority, stop checking.
 650                                                 break;
 651                                         }
 652                                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 653                                                 // This is going to error out below, but we want to
 654                                                 // provide a complete list.
 655                                                 $retInfos[] = $info;
 656                                         }
 657                                 }
 658                         }
 659                 }
 660
 661                 if ( count( $retInfos ) > 1 ) {
 662                         $ex = new \OverflowException(
 663                                 'Multiple sessions for this request tied for top priority: ' . join( ', ', $retInfos )
 664                         );
 665                         $ex->sessionInfos = $retInfos;
 666                         throw $ex;
 667                 }
 668
 669                 return $retInfos ? $retInfos[0] : null;
 670         }
 671
 672         /**
 673          * Load and verify the session info against the store
 674          *
 675          * @param SessionInfo &$info Will likely be replaced with an updated SessionInfo instance
 676          * @param WebRequest $request
 677          * @return bool Whether the session info matches the stored data (if any)
 678          */
 679         private function loadSessionInfoFromStore( SessionInfo &$info, WebRequest $request ) {
 680                 $key = wfMemcKey( 'MWSession', $info->getId() );
 681                 $blob = $this->store->get( $key );
 682
 683                 $newParams = [];
 684
 685                 if ( $blob !== false ) {
 686                         // Sanity check: blob must be an array, if it's saved at all
 687                         if ( !is_array( $blob ) ) {
 688                                 $this->logger->warning( 'Session "{session}": Bad data', [
 689                                         'session' => $info,
 690                                 ] );
 691                                 $this->store->delete( $key );
 692                                 return false;
 693                         }
 694
 695                         // Sanity check: blob has data and metadata arrays
 696                         if ( !isset( $blob['data'] ) || !is_array( $blob['data'] ) ||
 697                                 !isset( $blob['metadata'] ) || !is_array( $blob['metadata'] )
 698                         ) {
 699                                 $this->logger->warning( 'Session "{session}": Bad data structure', [
 700                                         'session' => $info,
 701                                 ] );
 702                                 $this->store->delete( $key );
 703                                 return false;
 704                         }
 705
 706                         $data = $blob['data'];
 707                         $metadata = $blob['metadata'];
 708
 709                         // Sanity check: metadata must be an array and must contain certain
 710                         // keys, if it's saved at all
 711                         if ( !array_key_exists( 'userId', $metadata ) ||
 712                                 !array_key_exists( 'userName', $metadata ) ||
 713                                 !array_key_exists( 'userToken', $metadata ) ||
 714                                 !array_key_exists( 'provider', $metadata )
 715                         ) {
 716                                 $this->logger->warning( 'Session "{session}": Bad metadata', [
 717                                         'session' => $info,
 718                                 ] );
 719                                 $this->store->delete( $key );
 720                                 return false;
 721                         }
 722
 723                         // First, load the provider from metadata, or validate it against the metadata.
 724                         $provider = $info->getProvider();
 725                         if ( $provider === null ) {
 726                                 $newParams['provider'] = $provider = $this->getProvider( $metadata['provider'] );
 727                                 if ( !$provider ) {
 728                                         $this->logger->warning(
 729                                                 'Session "{session}": Unknown provider ' . $metadata['provider'],
 730                                                 [
 731                                                         'session' => $info,
 732                                                 ]
 733                                         );
 734                                         $this->store->delete( $key );
 735                                         return false;
 736                                 }
 737                         } elseif ( $metadata['provider'] !== (string)$provider ) {
 738                                 $this->logger->warning( 'Session "{session}": Wrong provider ' .
 739                                         $metadata['provider'] . ' !== ' . $provider,
 740                                         [
 741                                                 'session' => $info,
 742                                 ] );
 743                                 return false;
 744                         }
 745
 746                         // Load provider metadata from metadata, or validate it against the metadata
 747                         $providerMetadata = $info->getProviderMetadata();
 748                         if ( isset( $metadata['providerMetadata'] ) ) {
 749                                 if ( $providerMetadata === null ) {
 750                                         $newParams['metadata'] = $metadata['providerMetadata'];
 751                                 } else {
 752                                         try {
 753                                                 $newProviderMetadata = $provider->mergeMetadata(
 754                                                         $metadata['providerMetadata'], $providerMetadata
 755                                                 );
 756                                                 if ( $newProviderMetadata !== $providerMetadata ) {
 757                                                         $newParams['metadata'] = $newProviderMetadata;
 758                                                 }
 759                                         } catch ( MetadataMergeException $ex ) {
 760                                                 $this->logger->warning(
 761                                                         'Session "{session}": Metadata merge failed: {exception}',
 762                                                         [
 763                                                                 'session' => $info,
 764                                                                 'exception' => $ex,
 765                                                         ] + $ex->getContext()
 766                                                 );
 767                                                 return false;
 768                                         }
 769                                 }
 770                         }
 771
 772                         // Next, load the user from metadata, or validate it against the metadata.
 773                         $userInfo = $info->getUserInfo();
 774                         if ( !$userInfo ) {
 775                                 // For loading, id is preferred to name.
 776                                 try {
 777                                         if ( $metadata['userId'] ) {
 778                                                 $userInfo = UserInfo::newFromId( $metadata['userId'] );
 779                                         } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 780                                                 $userInfo = UserInfo::newFromName( $metadata['userName'] );
 781                                         } else {
 782                                                 $userInfo = UserInfo::newAnonymous();
 783                                         }
 784                                 } catch ( \InvalidArgumentException $ex ) {
 785                                         $this->logger->error( 'Session "{session}": {exception}', [
 786                                                 'session' => $info,
 787                                                 'exception' => $ex,
 788                                         ] );
 789                                         return false;
 790                                 }
 791                                 $newParams['userInfo'] = $userInfo;
 792                         } else {
 793                                 // User validation passes if user ID matches, or if there
 794                                 // is no saved ID and the names match.
 795                                 if ( $metadata['userId'] ) {
 796                                         if ( $metadata['userId'] !== $userInfo->getId() ) {
 797                                                 $this->logger->warning(
 798                                                         'Session "{session}": User ID mismatch, {uid_a} !== {uid_b}',
 799                                                         [
 800                                                                 'session' => $info,
 801                                                                 'uid_a' => $metadata['userId'],
 802                                                                 'uid_b' => $userInfo->getId(),
 803                                                 ] );
 804                                                 return false;
 805                                         }
 806
 807                                         // If the user was renamed, probably best to fail here.
 808                                         if ( $metadata['userName'] !== null &&
 809                                                 $userInfo->getName() !== $metadata['userName']
 810                                         ) {
 811                                                 $this->logger->warning(
 812                                                         'Session "{session}": User ID matched but name didn\'t (rename?), {uname_a} !== {uname_b}',
 813                                                         [
 814                                                                 'session' => $info,
 815                                                                 'uname_a' => $metadata['userName'],
 816                                                                 'uname_b' => $userInfo->getName(),
 817                                                 ] );
 818                                                 return false;
 819                                         }
 820
 821                                 } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 822                                         if ( $metadata['userName'] !== $userInfo->getName() ) {
 823                                                 $this->logger->warning(
 824                                                         'Session "{session}": User name mismatch, {uname_a} !== {uname_b}',
 825                                                         [
 826                                                                 'session' => $info,
 827                                                                 'uname_a' => $metadata['userName'],
 828                                                                 'uname_b' => $userInfo->getName(),
 829                                                 ] );
 830                                                 return false;
 831                                         }
 832                                 } elseif ( !$userInfo->isAnon() ) {
 833                                         // Metadata specifies an anonymous user, but the passed-in
 834                                         // user isn't anonymous.
 835                                         $this->logger->warning(
 836                                                 'Session "{session}": Metadata has an anonymous user, but a non-anon user was provided',
 837                                                 [
 838                                                         'session' => $info,
 839                                         ] );
 840                                         return false;
 841                                 }
 842                         }
 843
 844                         // And if we have a token in the metadata, it must match the loaded/provided user.
 845                         if ( $metadata['userToken'] !== null &&
 846                                 $userInfo->getToken() !== $metadata['userToken']
 847                         ) {
 848                                 $this->logger->warning( 'Session "{session}": User token mismatch', [
 849                                         'session' => $info,
 850                                 ] );
 851                                 return false;
 852                         }
 853                         if ( !$userInfo->isVerified() ) {
 854                                 $newParams['userInfo'] = $userInfo->verified();
 855                         }
 856
 857                         if ( !empty( $metadata['remember'] ) && !$info->wasRemembered() ) {
 858                                 $newParams['remembered'] = true;
 859                         }
 860                         if ( !empty( $metadata['forceHTTPS'] ) && !$info->forceHTTPS() ) {
 861                                 $newParams['forceHTTPS'] = true;
 862                         }
 863                         if ( !empty( $metadata['persisted'] ) && !$info->wasPersisted() ) {
 864                                 $newParams['persisted'] = true;
 865                         }
 866
 867                         if ( !$info->isIdSafe() ) {
 868                                 $newParams['idIsSafe'] = true;
 869                         }
 870                 } else {
 871                         // No metadata, so we can't load the provider if one wasn't given.
 872                         if ( $info->getProvider() === null ) {
 873                                 $this->logger->warning(
 874                                         'Session "{session}": Null provider and no metadata',
 875                                         [
 876                                                 'session' => $info,
 877                                 ] );
 878                                 return false;
 879                         }
 880
 881                         // If no user was provided and no metadata, it must be anon.
 882                         if ( !$info->getUserInfo() ) {
 883                                 if ( $info->getProvider()->canChangeUser() ) {
 884                                         $newParams['userInfo'] = UserInfo::newAnonymous();
 885                                 } else {
 886                                         $this->logger->info(
 887                                                 'Session "{session}": No user provided and provider cannot set user',
 888                                                 [
 889                                                         'session' => $info,
 890                                         ] );
 891                                         return false;
 892                                 }
 893                         } elseif ( !$info->getUserInfo()->isVerified() ) {
 894                                 $this->logger->warning(
 895                                         'Session "{session}": Unverified user provided and no metadata to auth it',
 896                                         [
 897                                                 'session' => $info,
 898                                 ] );
 899                                 return false;
 900                         }
 901
 902                         $data = false;
 903                         $metadata = false;
 904
 905                         if ( !$info->getProvider()->persistsSessionId() && !$info->isIdSafe() ) {
 906                                 // The ID doesn't come from the user, so it should be safe
 907                                 // (and if not, nothing we can do about it anyway)
 908                                 $newParams['idIsSafe'] = true;
 909                         }
 910                 }
 911
 912                 // Construct the replacement SessionInfo, if necessary
 913                 if ( $newParams ) {
 914                         $newParams['copyFrom'] = $info;
 915                         $info = new SessionInfo( $info->getPriority(), $newParams );
 916                 }
 917
 918                 // Allow the provider to check the loaded SessionInfo
 919                 $providerMetadata = $info->getProviderMetadata();
 920                 if ( !$info->getProvider()->refreshSessionInfo( $info, $request, $providerMetadata ) ) {
 921                         return false;
 922                 }
 923                 if ( $providerMetadata !== $info->getProviderMetadata() ) {
 924                         $info = new SessionInfo( $info->getPriority(), [
 925                                 'metadata' => $providerMetadata,
 926                                 'copyFrom' => $info,
 927                         ] );
 928                 }
 929
 930                 // Give hooks a chance to abort. Combined with the SessionMetadata
 931                 // hook, this can allow for tying a session to an IP address or the
 932                 // like.
 933                 $reason = 'Hook aborted';
 934                 if ( !\Hooks::run(
 935                         'SessionCheckInfo',
 936                         [ &$reason, $info, $request, $metadata, $data ]
 937                 ) ) {
 938                         $this->logger->warning( 'Session "{session}": ' . $reason, [
 939                                 'session' => $info,
 940                         ] );
 941                         return false;
 942                 }
 943
 944                 return true;
 945         }
 946
 947         /**
 948          * Create a session corresponding to the passed SessionInfo
 949          * @private For use by a SessionProvider that needs to specially create its
 950          *  own session.
 951          * @param SessionInfo $info
 952          * @param WebRequest $request
 953          * @return Session
 954          */
 955         public function getSessionFromInfo( SessionInfo $info, WebRequest $request ) {
 956                 if ( defined( 'MW_NO_SESSION' ) ) {
 957                         if ( MW_NO_SESSION === 'warn' ) {
 958                                 // Undocumented safety case for converting existing entry points
 959                                 $this->logger->error( 'Sessions are supposed to be disabled for this entry point' );
 960                         } else {
 961                                 throw new \BadMethodCallException( 'Sessions are disabled for this entry point' );
 962                         }
 963                 }
 964
 965                 $id = $info->getId();
 966
 967                 if ( !isset( $this->allSessionBackends[$id] ) ) {
 968                         if ( !isset( $this->allSessionIds[$id] ) ) {
 969                                 $this->allSessionIds[$id] = new SessionId( $id );
 970                         }
 971                         $backend = new SessionBackend(
 972                                 $this->allSessionIds[$id],
 973                                 $info,
 974                                 $this->store,
 975                                 $this->logger,
 976                                 $this->config->get( 'ObjectCacheSessionExpiry' )
 977                         );
 978                         $this->allSessionBackends[$id] = $backend;
 979                         $delay = $backend->delaySave();
 980                 } else {
 981                         $backend = $this->allSessionBackends[$id];
 982                         $delay = $backend->delaySave();
 983                         if ( $info->wasPersisted() ) {
 984                                 $backend->persist();
 985                         }
 986                         if ( $info->wasRemembered() ) {
 987                                 $backend->setRememberUser( true );
 988                         }
 989                 }
 990
 991                 $request->setSessionId( $backend->getSessionId() );
 992                 $session = $backend->getSession( $request );
 993
 994                 if ( !$info->isIdSafe() ) {
 995                         $session->resetId();
 996                 }
 997
 998                 \ScopedCallback::consume( $delay );
 999                 return $session;
1000         }
1001
1002         /**
1003          * Deregister a SessionBackend
1004          * @private For use from \\MediaWiki\\Session\\SessionBackend only
1005          * @param SessionBackend $backend
1006          */
1007         public function deregisterSessionBackend( SessionBackend $backend ) {
1008                 $id = $backend->getId();
1009                 if ( !isset( $this->allSessionBackends[$id] ) || !isset( $this->allSessionIds[$id] ) ||
1010                         $this->allSessionBackends[$id] !== $backend ||
1011                         $this->allSessionIds[$id] !== $backend->getSessionId()
1012                 ) {
1013                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
1014                 }
1015
1016                 unset( $this->allSessionBackends[$id] );
1017                 // Explicitly do not unset $this->allSessionIds[$id]
1018         }
1019
1020         /**
1021          * Change a SessionBackend's ID
1022          * @private For use from \\MediaWiki\\Session\\SessionBackend only
1023          * @param SessionBackend $backend
1024          */
1025         public function changeBackendId( SessionBackend $backend ) {
1026                 $sessionId = $backend->getSessionId();
1027                 $oldId = (string)$sessionId;
1028                 if ( !isset( $this->allSessionBackends[$oldId] ) || !isset( $this->allSessionIds[$oldId] ) ||
1029                         $this->allSessionBackends[$oldId] !== $backend ||
1030                         $this->allSessionIds[$oldId] !== $sessionId
1031                 ) {
1032                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
1033                 }
1034
1035                 $newId = $this->generateSessionId();
1036
1037                 unset( $this->allSessionBackends[$oldId], $this->allSessionIds[$oldId] );
1038                 $sessionId->setId( $newId );
1039                 $this->allSessionBackends[$newId] = $backend;
1040                 $this->allSessionIds[$newId] = $sessionId;
1041         }
1042
1043         /**
1044          * Generate a new random session ID
1045          * @return string
1046          */
1047         public function generateSessionId() {
1048                 do {
1049                         $id = wfBaseConvert( \MWCryptRand::generateHex( 40 ), 16, 32, 32 );
1050                         $key = wfMemcKey( 'MWSession', $id );
1051                 } while ( isset( $this->allSessionIds[$id] ) || is_array( $this->store->get( $key ) ) );
1052                 return $id;
1053         }
1054
1055         /**
1056          * Call setters on a PHPSessionHandler
1057          * @private Use PhpSessionHandler::install()
1058          * @param PHPSessionHandler $handler
1059          */
1060         public function setupPHPSessionHandler( PHPSessionHandler $handler ) {
1061                 $handler->setManager( $this, $this->store, $this->logger );
1062         }
1063
1064         /**
1065          * Reset the internal caching for unit testing
1066          */
1067         public static function resetCache() {
1068                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
1069                         // @codeCoverageIgnoreStart
1070                         throw new MWException( __METHOD__ . ' may only be called from unit tests!' );
1071                         // @codeCoverageIgnoreEnd
1072                 }
1073
1074                 self::$globalSession = null;
1075                 self::$globalSessionRequest = null;
1076         }
1077
1078         /**
1079          * Do a sanity check to make sure the session is not used from many different IP addresses
1080          * and store some data for later sanity checks.
1081          * FIXME remove this once SessionManager is considered stable
1082          * @private For use in Setup.php only
1083          * @param Session $session Defaults to the global session.
1084          */
1085         public function checkIpLimits( Session $session = null ) {
1086                 $session = $session ?: self::getGlobalSession();
1087
1088                 try {
1089                         $ip = $session->getRequest()->getIP();
1090                 } catch ( \MWException $e ) {
1091                         return;
1092                 }
1093                 if ( $ip === '127.0.0.1' || \IP::isConfiguredProxy( $ip ) ) {
1094                         return;
1095                 }
1096                 $now = time();
1097
1098                 // Record (and possibly log) that the IP is using the current session.
1099                 // Don't touch the stored data unless we are adding a new IP or re-adding an expired one.
1100                 // This is slightly inaccurate (when an existing IP is seen again, the expiry is not
1101                 // extended) but that shouldn't make much difference and limits the session write frequency
1102                 // to # of IPs / $wgSuspiciousIpExpiry.
1103                 $data = $session->get( 'SessionManager-ip', [] );
1104                 if (
1105                         !isset( $data[$ip] )
1106                         || $data[$ip] < $now
1107                 ) {
1108                         $data[$ip] = time() + $this->config->get( 'SuspiciousIpExpiry' );
1109                         foreach ( $data as $key => $expires ) {
1110                                 if ( $expires < $now ) {
1111                                         unset( $data[$key] );
1112                                 }
1113                         }
1114                         $session->set( 'SessionManager-ip', $data );
1115
1116                         $logger = \MediaWiki\Logger\LoggerFactory::getInstance( 'session-ip' );
1117                         $logLevel = count( $data ) >= $this->config->get( 'SuspiciousIpPerSessionLimit' )
1118                                 ? LogLevel::WARNING : ( count( $data ) === 1 ? LogLevel::DEBUG : LogLevel::INFO );
1119                         $logger->log(
1120                                 $logLevel,
1121                                 'Same session used from {count} IPs',
1122                                 [
1123                                         'count' => count( $data ),
1124                                         'ips' => $data,
1125                                         'session' => $session->getId(),
1126                                         'user' => $session->getUser()->getName(),
1127                                         'persistent' => $session->isPersistent(),
1128                                 ]
1129                         );
1130                 }
1131
1132                 // Now do the same thing globally for the current user.
1133                 // We are using the object cache and assume it is shared between all wikis of a farm,
1134                 // and further assume that the same name belongs to the same user on all wikis. (It's either
1135                 // that or a central ID lookup which would mean an extra SQL query on every request.)
1136                 if ( $session->getUser()->isLoggedIn() ) {
1137                         $userKey = 'SessionManager-ip:' . md5( $session->getUser()->getName() );
1138                         $data = $this->store->get( $userKey ) ?: [];
1139                         if (
1140                                 !isset( $data[$ip] )
1141                                 || $data[$ip] < $now
1142                         ) {
1143                                 $data[$ip] = time() + $this->config->get( 'SuspiciousIpExpiry' );
1144                                 foreach ( $data as $key => $expires ) {
1145                                         if ( $expires < $now ) {
1146                                                 unset( $data[$key] );
1147                                         }
1148                                 }
1149                                 $this->store->set( $userKey, $data, $this->config->get( 'SuspiciousIpExpiry' ) );
1150                                 $logger = \MediaWiki\Logger\LoggerFactory::getInstance( 'session-ip' );
1151                                 $logLevel = count( $data ) >= $this->config->get( 'SuspiciousIpPerUserLimit' )
1152                                         ? LogLevel::WARNING : ( count( $data ) === 1 ? LogLevel::DEBUG : LogLevel::INFO );
1153                                 $logger->log(
1154                                         $logLevel,
1155                                         'Same user had sessions from {count} IPs',
1156                                         [
1157                                                 'count' => count( $data ),
1158                                                 'ips' => $data,
1159                                                 'session' => $session->getId(),
1160                                                 'user' => $session->getUser()->getName(),
1161                                                 'persistent' => $session->isPersistent(),
1162                                         ]
1163                                 );
1164                         }
1165                 }
1166         }
1167
1168         /**@}*/
1169
1170 }