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 = array();
  71
  72         /** @var SessionId[] */
  73         private $allSessionIds = array();
  74
  75         /** @var string[] */
  76         private $preventUsers = array();
  77
  78         /**
  79          * Get the global SessionManager
  80          * @return SessionManagerInterface
  81          *  (really a SessionManager, but this is to make IDEs less confused)
  82          */
  83         public static function singleton() {
  84                 if ( self::$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 = array() ) {
 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( array( $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, array( '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                                         array(
 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 = array();
 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 = array( $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 = array();
 303                         foreach ( $this->getProviders() as $provider ) {
 304                                 foreach ( $provider->getVaryHeaders() as $header => $options ) {
 305                                         if ( !isset( $headers[$header] ) ) {
 306                                                 $headers[$header] = array();
 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 = array();
 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( $user->getName() );
 361
 362                 // Fetch the user ID from the master, so that we don't try to create the user
 363                 // when they already exist, due to replication lag
 364                 // @codeCoverageIgnoreStart
 365                 if ( !$localId && wfGetLB()->getReaderIndex() != 0 ) {
 366                         $localId = User::idFromName( $user->getName(), User::READ_LATEST );
 367                 }
 368                 // @codeCoverageIgnoreEnd
 369
 370                 if ( $localId ) {
 371                         // User exists after all.
 372                         $user->setId( $localId );
 373                         $user->loadFromId();
 374                         return false;
 375                 }
 376
 377                 // Denied by AuthPlugin? But ignore AuthPlugin itself.
 378                 if ( get_class( $wgAuth ) !== 'AuthPlugin' && !$wgAuth->autoCreate() ) {
 379                         $logger->debug( __METHOD__ . ': denied by AuthPlugin' );
 380                         $user->setId( 0 );
 381                         $user->loadFromId();
 382                         return false;
 383                 }
 384
 385                 // Wiki is read-only?
 386                 if ( wfReadOnly() ) {
 387                         $logger->debug( __METHOD__ . ': denied by wfReadOnly()' );
 388                         $user->setId( 0 );
 389                         $user->loadFromId();
 390                         return false;
 391                 }
 392
 393                 $userName = $user->getName();
 394
 395                 // Check the session, if we tried to create this user already there's
 396                 // no point in retrying.
 397                 $session = self::getGlobalSession();
 398                 $reason = $session->get( 'MWSession::AutoCreateBlacklist' );
 399                 if ( $reason ) {
 400                         $logger->debug( __METHOD__ . ": blacklisted in session ($reason)" );
 401                         $user->setId( 0 );
 402                         $user->loadFromId();
 403                         return false;
 404                 }
 405
 406                 // Is the IP user able to create accounts?
 407                 $anon = new User;
 408                 if ( !$anon->isAllowedAny( 'createaccount', 'autocreateaccount' )
 409                         || $anon->isBlockedFromCreateAccount()
 410                 ) {
 411                         // Blacklist the user to avoid repeated DB queries subsequently
 412                         $logger->debug( __METHOD__ . ': user is blocked from this wiki, blacklisting' );
 413                         $session->set( 'MWSession::AutoCreateBlacklist', 'blocked', 600 );
 414                         $session->persist();
 415                         $user->setId( 0 );
 416                         $user->loadFromId();
 417                         return false;
 418                 }
 419
 420                 // Check for validity of username
 421                 if ( !User::isCreatableName( $userName ) ) {
 422                         $logger->debug( __METHOD__ . ': Invalid username, blacklisting' );
 423                         $session->set( 'MWSession::AutoCreateBlacklist', 'invalid username', 600 );
 424                         $session->persist();
 425                         $user->setId( 0 );
 426                         $user->loadFromId();
 427                         return false;
 428                 }
 429
 430                 // Give other extensions a chance to stop auto creation.
 431                 $user->loadDefaults( $userName );
 432                 $abortMessage = '';
 433                 if ( !\Hooks::run( 'AbortAutoAccount', array( $user, &$abortMessage ) ) ) {
 434                         // In this case we have no way to return the message to the user,
 435                         // but we can log it.
 436                         $logger->debug( __METHOD__ . ": denied by hook: $abortMessage" );
 437                         $session->set( 'MWSession::AutoCreateBlacklist', "hook aborted: $abortMessage", 600 );
 438                         $session->persist();
 439                         $user->setId( 0 );
 440                         $user->loadFromId();
 441                         return false;
 442                 }
 443
 444                 // Make sure the name has not been changed
 445                 if ( $user->getName() !== $userName ) {
 446                         $user->setId( 0 );
 447                         $user->loadFromId();
 448                         throw new \UnexpectedValueException(
 449                                 'AbortAutoAccount hook tried to change the user name'
 450                         );
 451                 }
 452
 453                 // Ignore warnings about master connections/writes...hard to avoid here
 454                 \Profiler::instance()->getTransactionProfiler()->resetExpectations();
 455
 456                 $cache = \ObjectCache::getLocalClusterInstance();
 457                 $backoffKey = wfMemcKey( 'MWSession', 'autocreate-failed', md5( $userName ) );
 458                 if ( $cache->get( $backoffKey ) ) {
 459                         $logger->debug( __METHOD__ . ': denied by prior creation attempt failures' );
 460                         $user->setId( 0 );
 461                         $user->loadFromId();
 462                         return false;
 463                 }
 464
 465                 // Checks passed, create the user...
 466                 $from = isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : 'CLI';
 467                 $logger->info( __METHOD__ . ': creating new user ({username}) - from: {url}',
 468                         array(
 469                                 'username' => $userName,
 470                                 'url' => $from,
 471                 ) );
 472
 473                 try {
 474                         // Insert the user into the local DB master
 475                         $status = $user->addToDatabase();
 476                         if ( !$status->isOK() ) {
 477                                 // @codeCoverageIgnoreStart
 478                                 $logger->error( __METHOD__ . ': failed with message ' . $status->getWikiText(),
 479                                         array(
 480                                                 'username' => $userName,
 481                                 ) );
 482                                 $user->setId( 0 );
 483                                 $user->loadFromId();
 484                                 return false;
 485                                 // @codeCoverageIgnoreEnd
 486                         }
 487                 } catch ( \Exception $ex ) {
 488                         // @codeCoverageIgnoreStart
 489                         $logger->error( __METHOD__ . ': failed with exception {exception}', array(
 490                                 'exception' => $ex,
 491                                 'username' => $userName,
 492                         ) );
 493                         // Do not keep throwing errors for a while
 494                         $cache->set( $backoffKey, 1, 600 );
 495                         // Bubble up error; which should normally trigger DB rollbacks
 496                         throw $ex;
 497                         // @codeCoverageIgnoreEnd
 498                 }
 499
 500                 # Notify AuthPlugin
 501                 $tmpUser = $user;
 502                 $wgAuth->initUser( $tmpUser, true );
 503                 if ( $tmpUser !== $user ) {
 504                         $logger->warning( __METHOD__ . ': ' .
 505                                 get_class( $wgAuth ) . '::initUser() replaced the user object' );
 506                 }
 507
 508                 # Notify hooks (e.g. Newuserlog)
 509                 \Hooks::run( 'AuthPluginAutoCreate', array( $user ) );
 510                 \Hooks::run( 'LocalUserCreated', array( $user, true ) );
 511
 512                 $user->saveSettings();
 513
 514                 # Update user count
 515                 \DeferredUpdates::addUpdate( new \SiteStatsUpdate( 0, 0, 0, 0, 1 ) );
 516
 517                 # Watch user's userpage and talk page
 518                 $user->addWatch( $user->getUserPage(), \WatchedItem::IGNORE_USER_RIGHTS );
 519
 520                 return true;
 521         }
 522
 523         /**
 524          * Prevent future sessions for the user
 525          *
 526          * The intention is that the named account will never again be usable for
 527          * normal login (i.e. there is no way to undo the prevention of access).
 528          *
 529          * @private For use from \\User::newSystemUser only
 530          * @param string $username
 531          */
 532         public function preventSessionsForUser( $username ) {
 533                 $this->preventUsers[$username] = true;
 534
 535                 // Instruct the session providers to kill any other sessions too.
 536                 foreach ( $this->getProviders() as $provider ) {
 537                         $provider->preventSessionsForUser( $username );
 538                 }
 539         }
 540
 541         /**
 542          * Test if a user is prevented
 543          * @private For use from SessionBackend only
 544          * @param string $username
 545          * @return bool
 546          */
 547         public function isUserSessionPrevented( $username ) {
 548                 return !empty( $this->preventUsers[$username] );
 549         }
 550
 551         /**
 552          * Get the available SessionProviders
 553          * @return SessionProvider[]
 554          */
 555         protected function getProviders() {
 556                 if ( $this->sessionProviders === null ) {
 557                         $this->sessionProviders = array();
 558                         foreach ( $this->config->get( 'SessionProviders' ) as $spec ) {
 559                                 $provider = \ObjectFactory::getObjectFromSpec( $spec );
 560                                 $provider->setLogger( $this->logger );
 561                                 $provider->setConfig( $this->config );
 562                                 $provider->setManager( $this );
 563                                 if ( isset( $this->sessionProviders[(string)$provider] ) ) {
 564                                         throw new \UnexpectedValueException( "Duplicate provider name \"$provider\"" );
 565                                 }
 566                                 $this->sessionProviders[(string)$provider] = $provider;
 567                         }
 568                 }
 569                 return $this->sessionProviders;
 570         }
 571
 572         /**
 573          * Get a session provider by name
 574          *
 575          * Generally, this will only be used by internal implementation of some
 576          * special session-providing mechanism. General purpose code, if it needs
 577          * to access a SessionProvider at all, will use Session::getProvider().
 578          *
 579          * @param string $name
 580          * @return SessionProvider|null
 581          */
 582         public function getProvider( $name ) {
 583                 $providers = $this->getProviders();
 584                 return isset( $providers[$name] ) ? $providers[$name] : null;
 585         }
 586
 587         /**
 588          * Save all active sessions on shutdown
 589          * @private For internal use with register_shutdown_function()
 590          */
 591         public function shutdown() {
 592                 if ( $this->allSessionBackends ) {
 593                         $this->logger->debug( 'Saving all sessions on shutdown' );
 594                         if ( session_id() !== '' ) {
 595                                 // @codeCoverageIgnoreStart
 596                                 session_write_close();
 597                         }
 598                         // @codeCoverageIgnoreEnd
 599                         foreach ( $this->allSessionBackends as $backend ) {
 600                                 $backend->save( true );
 601                         }
 602                 }
 603         }
 604
 605         /**
 606          * Fetch the SessionInfo(s) for a request
 607          * @param WebRequest $request
 608          * @return SessionInfo|null
 609          */
 610         private function getSessionInfoForRequest( WebRequest $request ) {
 611                 // Call all providers to fetch "the" session
 612                 $infos = array();
 613                 foreach ( $this->getProviders() as $provider ) {
 614                         $info = $provider->provideSessionInfo( $request );
 615                         if ( !$info ) {
 616                                 continue;
 617                         }
 618                         if ( $info->getProvider() !== $provider ) {
 619                                 throw new \UnexpectedValueException(
 620                                         "$provider returned session info for a different provider: $info"
 621                                 );
 622                         }
 623                         $infos[] = $info;
 624                 }
 625
 626                 // Sort the SessionInfos. Then find the first one that can be
 627                 // successfully loaded, and then all the ones after it with the same
 628                 // priority.
 629                 usort( $infos, 'MediaWiki\\Session\\SessionInfo::compare' );
 630                 $retInfos = array();
 631                 while ( $infos ) {
 632                         $info = array_pop( $infos );
 633                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 634                                 $retInfos[] = $info;
 635                                 while ( $infos ) {
 636                                         $info = array_pop( $infos );
 637                                         if ( SessionInfo::compare( $retInfos[0], $info ) ) {
 638                                                 // We hit a lower priority, stop checking.
 639                                                 break;
 640                                         }
 641                                         if ( $this->loadSessionInfoFromStore( $info, $request ) ) {
 642                                                 // This is going to error out below, but we want to
 643                                                 // provide a complete list.
 644                                                 $retInfos[] = $info;
 645                                         }
 646                                 }
 647                         }
 648                 }
 649
 650                 if ( count( $retInfos ) > 1 ) {
 651                         $ex = new \OverflowException(
 652                                 'Multiple sessions for this request tied for top priority: ' . join( ', ', $retInfos )
 653                         );
 654                         $ex->sessionInfos = $retInfos;
 655                         throw $ex;
 656                 }
 657
 658                 return $retInfos ? $retInfos[0] : null;
 659         }
 660
 661         /**
 662          * Load and verify the session info against the store
 663          *
 664          * @param SessionInfo &$info Will likely be replaced with an updated SessionInfo instance
 665          * @param WebRequest $request
 666          * @return bool Whether the session info matches the stored data (if any)
 667          */
 668         private function loadSessionInfoFromStore( SessionInfo &$info, WebRequest $request ) {
 669                 $key = wfMemcKey( 'MWSession', $info->getId() );
 670                 $blob = $this->store->get( $key );
 671
 672                 $newParams = array();
 673
 674                 if ( $blob !== false ) {
 675                         // Sanity check: blob must be an array, if it's saved at all
 676                         if ( !is_array( $blob ) ) {
 677                                 $this->logger->warning( 'Session "{session}": Bad data', array(
 678                                         'session' => $info,
 679                                 ) );
 680                                 $this->store->delete( $key );
 681                                 return false;
 682                         }
 683
 684                         // Sanity check: blob has data and metadata arrays
 685                         if ( !isset( $blob['data'] ) || !is_array( $blob['data'] ) ||
 686                                 !isset( $blob['metadata'] ) || !is_array( $blob['metadata'] )
 687                         ) {
 688                                 $this->logger->warning( 'Session "{session}": Bad data structure', array(
 689                                         'session' => $info,
 690                                 ) );
 691                                 $this->store->delete( $key );
 692                                 return false;
 693                         }
 694
 695                         $data = $blob['data'];
 696                         $metadata = $blob['metadata'];
 697
 698                         // Sanity check: metadata must be an array and must contain certain
 699                         // keys, if it's saved at all
 700                         if ( !array_key_exists( 'userId', $metadata ) ||
 701                                 !array_key_exists( 'userName', $metadata ) ||
 702                                 !array_key_exists( 'userToken', $metadata ) ||
 703                                 !array_key_exists( 'provider', $metadata )
 704                         ) {
 705                                 $this->logger->warning( 'Session "{session}": Bad metadata', array(
 706                                         'session' => $info,
 707                                 ) );
 708                                 $this->store->delete( $key );
 709                                 return false;
 710                         }
 711
 712                         // First, load the provider from metadata, or validate it against the metadata.
 713                         $provider = $info->getProvider();
 714                         if ( $provider === null ) {
 715                                 $newParams['provider'] = $provider = $this->getProvider( $metadata['provider'] );
 716                                 if ( !$provider ) {
 717                                         $this->logger->warning(
 718                                                 'Session "{session}": Unknown provider ' . $metadata['provider'],
 719                                                 array(
 720                                                         'session' => $info,
 721                                                 )
 722                                         );
 723                                         $this->store->delete( $key );
 724                                         return false;
 725                                 }
 726                         } elseif ( $metadata['provider'] !== (string)$provider ) {
 727                                 $this->logger->warning( 'Session "{session}": Wrong provider ' .
 728                                         $metadata['provider'] . ' !== ' . $provider,
 729                                         array(
 730                                                 'session' => $info,
 731                                 ) );
 732                                 return false;
 733                         }
 734
 735                         // Load provider metadata from metadata, or validate it against the metadata
 736                         $providerMetadata = $info->getProviderMetadata();
 737                         if ( isset( $metadata['providerMetadata'] ) ) {
 738                                 if ( $providerMetadata === null ) {
 739                                         $newParams['metadata'] = $metadata['providerMetadata'];
 740                                 } else {
 741                                         try {
 742                                                 $newProviderMetadata = $provider->mergeMetadata(
 743                                                         $metadata['providerMetadata'], $providerMetadata
 744                                                 );
 745                                                 if ( $newProviderMetadata !== $providerMetadata ) {
 746                                                         $newParams['metadata'] = $newProviderMetadata;
 747                                                 }
 748                                         } catch ( MetadataMergeException $ex ) {
 749                                                 $this->logger->warning(
 750                                                         'Session "{session}": Metadata merge failed: {exception}',
 751                                                         array(
 752                                                                 'session' => $info,
 753                                                                 'exception' => $ex,
 754                                                         ) + $ex->getContext()
 755                                                 );
 756                                                 return false;
 757                                         }
 758                                 }
 759                         }
 760
 761                         // Next, load the user from metadata, or validate it against the metadata.
 762                         $userInfo = $info->getUserInfo();
 763                         if ( !$userInfo ) {
 764                                 // For loading, id is preferred to name.
 765                                 try {
 766                                         if ( $metadata['userId'] ) {
 767                                                 $userInfo = UserInfo::newFromId( $metadata['userId'] );
 768                                         } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 769                                                 $userInfo = UserInfo::newFromName( $metadata['userName'] );
 770                                         } else {
 771                                                 $userInfo = UserInfo::newAnonymous();
 772                                         }
 773                                 } catch ( \InvalidArgumentException $ex ) {
 774                                         $this->logger->error( 'Session "{session}": {exception}', array(
 775                                                 'session' => $info,
 776                                                 'exception' => $ex,
 777                                         ) );
 778                                         return false;
 779                                 }
 780                                 $newParams['userInfo'] = $userInfo;
 781                         } else {
 782                                 // User validation passes if user ID matches, or if there
 783                                 // is no saved ID and the names match.
 784                                 if ( $metadata['userId'] ) {
 785                                         if ( $metadata['userId'] !== $userInfo->getId() ) {
 786                                                 $this->logger->warning(
 787                                                         'Session "{session}": User ID mismatch, {uid_a} !== {uid_b}',
 788                                                         array(
 789                                                                 'session' => $info,
 790                                                                 'uid_a' => $metadata['userId'],
 791                                                                 'uid_b' => $userInfo->getId(),
 792                                                 ) );
 793                                                 return false;
 794                                         }
 795
 796                                         // If the user was renamed, probably best to fail here.
 797                                         if ( $metadata['userName'] !== null &&
 798                                                 $userInfo->getName() !== $metadata['userName']
 799                                         ) {
 800                                                 $this->logger->warning(
 801                                                         'Session "{session}": User ID matched but name didn\'t (rename?), {uname_a} !== {uname_b}',
 802                                                         array(
 803                                                                 'session' => $info,
 804                                                                 'uname_a' => $metadata['userName'],
 805                                                                 'uname_b' => $userInfo->getName(),
 806                                                 ) );
 807                                                 return false;
 808                                         }
 809
 810                                 } elseif ( $metadata['userName'] !== null ) { // Shouldn't happen, but just in case
 811                                         if ( $metadata['userName'] !== $userInfo->getName() ) {
 812                                                 $this->logger->warning(
 813                                                         'Session "{session}": User name mismatch, {uname_a} !== {uname_b}',
 814                                                         array(
 815                                                                 'session' => $info,
 816                                                                 'uname_a' => $metadata['userName'],
 817                                                                 'uname_b' => $userInfo->getName(),
 818                                                 ) );
 819                                                 return false;
 820                                         }
 821                                 } elseif ( !$userInfo->isAnon() ) {
 822                                         // Metadata specifies an anonymous user, but the passed-in
 823                                         // user isn't anonymous.
 824                                         $this->logger->warning(
 825                                                 'Session "{session}": Metadata has an anonymous user, but a non-anon user was provided',
 826                                                 array(
 827                                                         'session' => $info,
 828                                         ) );
 829                                         return false;
 830                                 }
 831                         }
 832
 833                         // And if we have a token in the metadata, it must match the loaded/provided user.
 834                         if ( $metadata['userToken'] !== null &&
 835                                 $userInfo->getToken() !== $metadata['userToken']
 836                         ) {
 837                                 $this->logger->warning( 'Session "{session}": User token mismatch', array(
 838                                         'session' => $info,
 839                                 ) );
 840                                 return false;
 841                         }
 842                         if ( !$userInfo->isVerified() ) {
 843                                 $newParams['userInfo'] = $userInfo->verified();
 844                         }
 845
 846                         if ( !empty( $metadata['remember'] ) && !$info->wasRemembered() ) {
 847                                 $newParams['remembered'] = true;
 848                         }
 849                         if ( !empty( $metadata['forceHTTPS'] ) && !$info->forceHTTPS() ) {
 850                                 $newParams['forceHTTPS'] = true;
 851                         }
 852                         if ( !empty( $metadata['persisted'] ) && !$info->wasPersisted() ) {
 853                                 $newParams['persisted'] = true;
 854                         }
 855
 856                         if ( !$info->isIdSafe() ) {
 857                                 $newParams['idIsSafe'] = true;
 858                         }
 859                 } else {
 860                         // No metadata, so we can't load the provider if one wasn't given.
 861                         if ( $info->getProvider() === null ) {
 862                                 $this->logger->warning(
 863                                         'Session "{session}": Null provider and no metadata',
 864                                         array(
 865                                                 'session' => $info,
 866                                 ) );
 867                                 return false;
 868                         }
 869
 870                         // If no user was provided and no metadata, it must be anon.
 871                         if ( !$info->getUserInfo() ) {
 872                                 if ( $info->getProvider()->canChangeUser() ) {
 873                                         $newParams['userInfo'] = UserInfo::newAnonymous();
 874                                 } else {
 875                                         $this->logger->info(
 876                                                 'Session "{session}": No user provided and provider cannot set user',
 877                                                 array(
 878                                                         'session' => $info,
 879                                         ) );
 880                                         return false;
 881                                 }
 882                         } elseif ( !$info->getUserInfo()->isVerified() ) {
 883                                 $this->logger->warning(
 884                                         'Session "{session}": Unverified user provided and no metadata to auth it',
 885                                         array(
 886                                                 'session' => $info,
 887                                 ) );
 888                                 return false;
 889                         }
 890
 891                         $data = false;
 892                         $metadata = false;
 893
 894                         if ( !$info->getProvider()->persistsSessionId() && !$info->isIdSafe() ) {
 895                                 // The ID doesn't come from the user, so it should be safe
 896                                 // (and if not, nothing we can do about it anyway)
 897                                 $newParams['idIsSafe'] = true;
 898                         }
 899                 }
 900
 901                 // Construct the replacement SessionInfo, if necessary
 902                 if ( $newParams ) {
 903                         $newParams['copyFrom'] = $info;
 904                         $info = new SessionInfo( $info->getPriority(), $newParams );
 905                 }
 906
 907                 // Allow the provider to check the loaded SessionInfo
 908                 $providerMetadata = $info->getProviderMetadata();
 909                 if ( !$info->getProvider()->refreshSessionInfo( $info, $request, $providerMetadata ) ) {
 910                         return false;
 911                 }
 912                 if ( $providerMetadata !== $info->getProviderMetadata() ) {
 913                         $info = new SessionInfo( $info->getPriority(), array(
 914                                 'metadata' => $providerMetadata,
 915                                 'copyFrom' => $info,
 916                         ) );
 917                 }
 918
 919                 // Give hooks a chance to abort. Combined with the SessionMetadata
 920                 // hook, this can allow for tying a session to an IP address or the
 921                 // like.
 922                 $reason = 'Hook aborted';
 923                 if ( !\Hooks::run(
 924                         'SessionCheckInfo',
 925                         array( &$reason, $info, $request, $metadata, $data )
 926                 ) ) {
 927                         $this->logger->warning( 'Session "{session}": ' . $reason, array(
 928                                 'session' => $info,
 929                         ) );
 930                         return false;
 931                 }
 932
 933                 return true;
 934         }
 935
 936         /**
 937          * Create a session corresponding to the passed SessionInfo
 938          * @private For use by a SessionProvider that needs to specially create its
 939          *  own session.
 940          * @param SessionInfo $info
 941          * @param WebRequest $request
 942          * @return Session
 943          */
 944         public function getSessionFromInfo( SessionInfo $info, WebRequest $request ) {
 945                 $id = $info->getId();
 946
 947                 if ( !isset( $this->allSessionBackends[$id] ) ) {
 948                         if ( !isset( $this->allSessionIds[$id] ) ) {
 949                                 $this->allSessionIds[$id] = new SessionId( $id );
 950                         }
 951                         $backend = new SessionBackend(
 952                                 $this->allSessionIds[$id],
 953                                 $info,
 954                                 $this->store,
 955                                 $this->logger,
 956                                 $this->config->get( 'ObjectCacheSessionExpiry' )
 957                         );
 958                         $this->allSessionBackends[$id] = $backend;
 959                         $delay = $backend->delaySave();
 960                 } else {
 961                         $backend = $this->allSessionBackends[$id];
 962                         $delay = $backend->delaySave();
 963                         if ( $info->wasPersisted() ) {
 964                                 $backend->persist();
 965                         }
 966                         if ( $info->wasRemembered() ) {
 967                                 $backend->setRememberUser( true );
 968                         }
 969                 }
 970
 971                 $request->setSessionId( $backend->getSessionId() );
 972                 $session = $backend->getSession( $request );
 973
 974                 if ( !$info->isIdSafe() ) {
 975                         $session->resetId();
 976                 }
 977
 978                 \ScopedCallback::consume( $delay );
 979                 return $session;
 980         }
 981
 982         /**
 983          * Deregister a SessionBackend
 984          * @private For use from \\MediaWiki\\Session\\SessionBackend only
 985          * @param SessionBackend $backend
 986          */
 987         public function deregisterSessionBackend( SessionBackend $backend ) {
 988                 $id = $backend->getId();
 989                 if ( !isset( $this->allSessionBackends[$id] ) || !isset( $this->allSessionIds[$id] ) ||
 990                         $this->allSessionBackends[$id] !== $backend ||
 991                         $this->allSessionIds[$id] !== $backend->getSessionId()
 992                 ) {
 993                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
 994                 }
 995
 996                 unset( $this->allSessionBackends[$id] );
 997                 // Explicitly do not unset $this->allSessionIds[$id]
 998         }
 999
1000         /**
1001          * Change a SessionBackend's ID
1002          * @private For use from \\MediaWiki\\Session\\SessionBackend only
1003          * @param SessionBackend $backend
1004          */
1005         public function changeBackendId( SessionBackend $backend ) {
1006                 $sessionId = $backend->getSessionId();
1007                 $oldId = (string)$sessionId;
1008                 if ( !isset( $this->allSessionBackends[$oldId] ) || !isset( $this->allSessionIds[$oldId] ) ||
1009                         $this->allSessionBackends[$oldId] !== $backend ||
1010                         $this->allSessionIds[$oldId] !== $sessionId
1011                 ) {
1012                         throw new \InvalidArgumentException( 'Backend was not registered with this SessionManager' );
1013                 }
1014
1015                 $newId = $this->generateSessionId();
1016
1017                 unset( $this->allSessionBackends[$oldId], $this->allSessionIds[$oldId] );
1018                 $sessionId->setId( $newId );
1019                 $this->allSessionBackends[$newId] = $backend;
1020                 $this->allSessionIds[$newId] = $sessionId;
1021         }
1022
1023         /**
1024          * Generate a new random session ID
1025          * @return string
1026          */
1027         public function generateSessionId() {
1028                 do {
1029                         $id = wfBaseConvert( \MWCryptRand::generateHex( 40 ), 16, 32, 32 );
1030                         $key = wfMemcKey( 'MWSession', $id );
1031                 } while ( isset( $this->allSessionIds[$id] ) || is_array( $this->store->get( $key ) ) );
1032                 return $id;
1033         }
1034
1035         /**
1036          * Call setters on a PHPSessionHandler
1037          * @private Use PhpSessionHandler::install()
1038          * @param PHPSessionHandler $handler
1039          */
1040         public function setupPHPSessionHandler( PHPSessionHandler $handler ) {
1041                 $handler->setManager( $this, $this->store, $this->logger );
1042         }
1043
1044         /**
1045          * Reset the internal caching for unit testing
1046          */
1047         public static function resetCache() {
1048                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
1049                         // @codeCoverageIgnoreStart
1050                         throw new MWException( __METHOD__ . ' may only be called from unit tests!' );
1051                         // @codeCoverageIgnoreEnd
1052                 }
1053
1054                 self::$globalSession = null;
1055                 self::$globalSessionRequest = null;
1056         }
1057
1058         /**
1059          * Do a sanity check to make sure the session is not used from many different IP addresses
1060          * and store some data for later sanity checks.
1061          * FIXME remove this once SessionManager is considered stable
1062          * @private For use in Setup.php only
1063          * @param Session $session Defaults to the global session.
1064          */
1065         public function checkIpLimits( Session $session = null ) {
1066                 $session = $session ?: self::getGlobalSession();
1067
1068                 try {
1069                         $ip = $session->getRequest()->getIP();
1070                 } catch ( \MWException $e ) {
1071                         return;
1072                 }
1073                 if ( $ip === '127.0.0.1' || \IP::isConfiguredProxy( $ip ) ) {
1074                         return;
1075                 }
1076                 $now = time();
1077
1078                 // Record (and possibly log) that the IP is using the current session.
1079                 // Don't touch the stored data unless we are adding a new IP or re-adding an expired one.
1080                 // This is slightly inaccurate (when an existing IP is seen again, the expiry is not
1081                 // extended) but that shouldn't make much difference and limits the session write frequency
1082                 // to # of IPs / $wgSuspiciousIpExpiry.
1083                 $data = $session->get( 'SessionManager-ip', array() );
1084                 if (
1085                         !isset( $data[$ip] )
1086                         || $data[$ip] < $now
1087                 ) {
1088                         $data[$ip] = time() + $this->config->get( 'SuspiciousIpExpiry' );
1089                         foreach ( $data as $key => $expires ) {
1090                                 if ( $expires < $now ) {
1091                                         unset( $data[$key] );
1092                                 }
1093                         }
1094                         $session->set( 'SessionManager-ip', $data );
1095
1096                         $logger = \MediaWiki\Logger\LoggerFactory::getInstance( 'session-ip' );
1097                         $logLevel = count( $data ) >= $this->config->get( 'SuspiciousIpPerSessionLimit' )
1098                                 ? LogLevel::WARNING : ( count( $data ) === 1 ? LogLevel::DEBUG : LogLevel::INFO );
1099                         $logger->log(
1100                                 $logLevel,
1101                                 'Same session used from {count} IPs',
1102                                 array(
1103                                         'count' => count( $data ),
1104                                         'ips' => $data,
1105                                         'session' => $session->getId(),
1106                                         'user' => $session->getUser()->getName(),
1107                                         'persistent' => $session->isPersistent(),
1108                                 )
1109                         );
1110                 }
1111
1112                 // Now do the same thing globally for the current user.
1113                 // We are using the object cache and assume it is shared between all wikis of a farm,
1114                 // and further assume that the same name belongs to the same user on all wikis. (It's either
1115                 // that or a central ID lookup which would mean an extra SQL query on every request.)
1116                 if ( $session->getUser()->isLoggedIn() ) {
1117                         $userKey = 'SessionManager-ip:' . md5( $session->getUser()->getName() );
1118                         $data = $this->store->get( $userKey ) ?: array();
1119                         if (
1120                                 !isset( $data[$ip] )
1121                                 || $data[$ip] < $now
1122                         ) {
1123                                 $data[$ip] = time() + $this->config->get( 'SuspiciousIpExpiry' );
1124                                 foreach ( $data as $key => $expires ) {
1125                                         if ( $expires < $now ) {
1126                                                 unset( $data[$key] );
1127                                         }
1128                                 }
1129                                 $this->store->set( $userKey, $data, $this->config->get( 'SuspiciousIpExpiry' ) );
1130                                 $logger = \MediaWiki\Logger\LoggerFactory::getInstance( 'session-ip' );
1131                                 $logLevel = count( $data ) >= $this->config->get( 'SuspiciousIpPerUserLimit' )
1132                                         ? LogLevel::WARNING : ( count( $data ) === 1 ? LogLevel::DEBUG : LogLevel::INFO );
1133                                 $logger->log(
1134                                         $logLevel,
1135                                         'Same user had sessions from {count} IPs',
1136                                         array(
1137                                                 'count' => count( $data ),
1138                                                 'ips' => $data,
1139                                                 'session' => $session->getId(),
1140                                                 'user' => $session->getUser()->getName(),
1141                                                 'persistent' => $session->isPersistent(),
1142                                         )
1143                                 );
1144                         }
1145                 }
1146         }
1147
1148         /**@}*/
1149
1150 }