includes/session/SessionBackend.php

   1 <?php
   2 /**
   3  * MediaWiki session backend
   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 CachedBagOStuff;
  27 use Psr\Log\LoggerInterface;
  28 use User;
  29 use WebRequest;
  30
  31 /**
  32  * This is the actual workhorse for Session.
  33  *
  34  * Most code does not need to use this class, you want \\MediaWiki\\Session\\Session.
  35  * The exceptions are SessionProviders and SessionMetadata hook functions,
  36  * which get an instance of this class rather than Session.
  37  *
  38  * The reasons for this split are:
  39  * 1. A session can be attached to multiple requests, but we want the Session
  40  *    object to have some features that correspond to just one of those
  41  *    requests.
  42  * 2. We want reasonable garbage collection behavior, but we also want the
  43  *    SessionManager to hold a reference to every active session so it can be
  44  *    saved when the request ends.
  45  *
  46  * @ingroup Session
  47  * @since 1.27
  48  */
  49 final class SessionBackend {
  50         /** @var SessionId */
  51         private $id;
  52
  53         private $persist = false;
  54         private $remember = false;
  55         private $forceHTTPS = false;
  56
  57         /** @var array|null */
  58         private $data = null;
  59
  60         private $forcePersist = false;
  61         private $metaDirty = false;
  62         private $dataDirty = false;
  63
  64         /** @var string Used to detect subarray modifications */
  65         private $dataHash = null;
  66
  67         /** @var CachedBagOStuff */
  68         private $store;
  69
  70         /** @var LoggerInterface */
  71         private $logger;
  72
  73         /** @var int */
  74         private $lifetime;
  75
  76         /** @var User */
  77         private $user;
  78
  79         private $curIndex = 0;
  80
  81         /** @var WebRequest[] Session requests */
  82         private $requests = array();
  83
  84         /** @var SessionProvider provider */
  85         private $provider;
  86
  87         /** @var array|null provider-specified metadata */
  88         private $providerMetadata = null;
  89
  90         private $expires = 0;
  91         private $loggedOut = 0;
  92         private $delaySave = 0;
  93
  94         private $usePhpSessionHandling = true;
  95         private $checkPHPSessionRecursionGuard = false;
  96
  97         /**
  98          * @param SessionId $id Session ID object
  99          * @param SessionInfo $info Session info to populate from
 100          * @param CachedBagOStuff $store Backend data store
 101          * @param LoggerInterface $logger
 102          * @param int $lifetime Session data lifetime in seconds
 103          */
 104         public function __construct(
 105                 SessionId $id, SessionInfo $info, CachedBagOStuff $store, LoggerInterface $logger, $lifetime
 106         ) {
 107                 $phpSessionHandling = \RequestContext::getMain()->getConfig()->get( 'PHPSessionHandling' );
 108                 $this->usePhpSessionHandling = $phpSessionHandling !== 'disable';
 109
 110                 if ( $info->getUserInfo() && !$info->getUserInfo()->isVerified() ) {
 111                         throw new \InvalidArgumentException(
 112                                 "Refusing to create session for unverified user {$info->getUserInfo()}"
 113                         );
 114                 }
 115                 if ( $info->getProvider() === null ) {
 116                         throw new \InvalidArgumentException( 'Cannot create session without a provider' );
 117                 }
 118                 if ( $info->getId() !== $id->getId() ) {
 119                         throw new \InvalidArgumentException( 'SessionId and SessionInfo don\'t match' );
 120                 }
 121
 122                 $this->id = $id;
 123                 $this->user = $info->getUserInfo() ? $info->getUserInfo()->getUser() : new User;
 124                 $this->store = $store;
 125                 $this->logger = $logger;
 126                 $this->lifetime = $lifetime;
 127                 $this->provider = $info->getProvider();
 128                 $this->persist = $info->wasPersisted();
 129                 $this->remember = $info->wasRemembered();
 130                 $this->forceHTTPS = $info->forceHTTPS();
 131                 $this->providerMetadata = $info->getProviderMetadata();
 132
 133                 $blob = $store->get( wfMemcKey( 'MWSession', (string)$this->id ) );
 134                 if ( !is_array( $blob ) ||
 135                         !isset( $blob['metadata'] ) || !is_array( $blob['metadata'] ) ||
 136                         !isset( $blob['data'] ) || !is_array( $blob['data'] )
 137                 ) {
 138                         $this->data = array();
 139                         $this->dataDirty = true;
 140                         $this->metaDirty = true;
 141                         $this->logger->debug(
 142                                 'SessionBackend "{session}" is unsaved, marking dirty in constructor',
 143                                 array(
 144                                         'session' => $this->id,
 145                         ) );
 146                 } else {
 147                         $this->data = $blob['data'];
 148                         if ( isset( $blob['metadata']['loggedOut'] ) ) {
 149                                 $this->loggedOut = (int)$blob['metadata']['loggedOut'];
 150                         }
 151                         if ( isset( $blob['metadata']['expires'] ) ) {
 152                                 $this->expires = (int)$blob['metadata']['expires'];
 153                         } else {
 154                                 $this->metaDirty = true;
 155                                 $this->logger->debug(
 156                                         'SessionBackend "{session}" metadata dirty due to missing expiration timestamp',
 157                                 array(
 158                                         'session' => $this->id,
 159                                 ) );
 160                         }
 161                 }
 162                 $this->dataHash = md5( serialize( $this->data ) );
 163         }
 164
 165         /**
 166          * Return a new Session for this backend
 167          * @param WebRequest $request
 168          * @return Session
 169          */
 170         public function getSession( WebRequest $request ) {
 171                 $index = ++$this->curIndex;
 172                 $this->requests[$index] = $request;
 173                 $session = new Session( $this, $index );
 174                 return $session;
 175         }
 176
 177         /**
 178          * Deregister a Session
 179          * @private For use by \\MediaWiki\\Session\\Session::__destruct() only
 180          * @param int $index
 181          */
 182         public function deregisterSession( $index ) {
 183                 unset( $this->requests[$index] );
 184                 if ( !count( $this->requests ) ) {
 185                         $this->save( true );
 186                         $this->provider->getManager()->deregisterSessionBackend( $this );
 187                 }
 188         }
 189
 190         /**
 191          * Returns the session ID.
 192          * @return string
 193          */
 194         public function getId() {
 195                 return (string)$this->id;
 196         }
 197
 198         /**
 199          * Fetch the SessionId object
 200          * @private For internal use by WebRequest
 201          * @return SessionId
 202          */
 203         public function getSessionId() {
 204                 return $this->id;
 205         }
 206
 207         /**
 208          * Changes the session ID
 209          * @return string New ID (might be the same as the old)
 210          */
 211         public function resetId() {
 212                 if ( $this->provider->persistsSessionId() ) {
 213                         $oldId = (string)$this->id;
 214                         $restart = $this->usePhpSessionHandling && $oldId === session_id() &&
 215                                 PHPSessionHandler::isEnabled();
 216
 217                         if ( $restart ) {
 218                                 // If this session is the one behind PHP's $_SESSION, we need
 219                                 // to close then reopen it.
 220                                 session_write_close();
 221                         }
 222
 223                         $this->provider->getManager()->changeBackendId( $this );
 224                         $this->provider->sessionIdWasReset( $this, $oldId );
 225                         $this->metaDirty = true;
 226                         $this->logger->debug(
 227                                 'SessionBackend "{session}" metadata dirty due to ID reset (formerly "{oldId}")',
 228                                 array(
 229                                         'session' => $this->id,
 230                                         'oldId' => $oldId,
 231                         ) );
 232
 233                         if ( $restart ) {
 234                                 session_id( (string)$this->id );
 235                                 \MediaWiki\quietCall( 'session_start' );
 236                         }
 237
 238                         $this->autosave();
 239
 240                         // Delete the data for the old session ID now
 241                         $this->store->delete( wfMemcKey( 'MWSession', $oldId ) );
 242                 }
 243         }
 244
 245         /**
 246          * Fetch the SessionProvider for this session
 247          * @return SessionProviderInterface
 248          */
 249         public function getProvider() {
 250                 return $this->provider;
 251         }
 252
 253         /**
 254          * Indicate whether this session is persisted across requests
 255          *
 256          * For example, if cookies are set.
 257          *
 258          * @return bool
 259          */
 260         public function isPersistent() {
 261                 return $this->persist;
 262         }
 263
 264         /**
 265          * Make this session persisted across requests
 266          *
 267          * If the session is already persistent, equivalent to calling
 268          * $this->renew().
 269          */
 270         public function persist() {
 271                 if ( !$this->persist ) {
 272                         $this->persist = true;
 273                         $this->forcePersist = true;
 274                         $this->metaDirty = true;
 275                         $this->logger->debug(
 276                                 'SessionBackend "{session}" force-persist due to persist()',
 277                                 array(
 278                                         'session' => $this->id,
 279                         ) );
 280                         $this->autosave();
 281                 } else {
 282                         $this->renew();
 283                 }
 284         }
 285
 286         /**
 287          * Indicate whether the user should be remembered independently of the
 288          * session ID.
 289          * @return bool
 290          */
 291         public function shouldRememberUser() {
 292                 return $this->remember;
 293         }
 294
 295         /**
 296          * Set whether the user should be remembered independently of the session
 297          * ID.
 298          * @param bool $remember
 299          */
 300         public function setRememberUser( $remember ) {
 301                 if ( $this->remember !== (bool)$remember ) {
 302                         $this->remember = (bool)$remember;
 303                         $this->metaDirty = true;
 304                         $this->logger->debug(
 305                                 'SessionBackend "{session}" metadata dirty due to remember-user change',
 306                                 array(
 307                                         'session' => $this->id,
 308                         ) );
 309                         $this->autosave();
 310                 }
 311         }
 312
 313         /**
 314          * Returns the request associated with a Session
 315          * @param int $index Session index
 316          * @return WebRequest
 317          */
 318         public function getRequest( $index ) {
 319                 if ( !isset( $this->requests[$index] ) ) {
 320                         throw new \InvalidArgumentException( 'Invalid session index' );
 321                 }
 322                 return $this->requests[$index];
 323         }
 324
 325         /**
 326          * Returns the authenticated user for this session
 327          * @return User
 328          */
 329         public function getUser() {
 330                 return $this->user;
 331         }
 332
 333         /**
 334          * Fetch the rights allowed the user when this session is active.
 335          * @return null|string[] Allowed user rights, or null to allow all.
 336          */
 337         public function getAllowedUserRights() {
 338                 return $this->provider->getAllowedUserRights( $this );
 339         }
 340
 341         /**
 342          * Indicate whether the session user info can be changed
 343          * @return bool
 344          */
 345         public function canSetUser() {
 346                 return $this->provider->canChangeUser();
 347         }
 348
 349         /**
 350          * Set a new user for this session
 351          * @note This should only be called when the user has been authenticated via a login process
 352          * @param User $user User to set on the session.
 353          *   This may become a "UserValue" in the future, or User may be refactored
 354          *   into such.
 355          */
 356         public function setUser( $user ) {
 357                 if ( !$this->canSetUser() ) {
 358                         throw new \BadMethodCallException(
 359                                 'Cannot set user on this session; check $session->canSetUser() first'
 360                         );
 361                 }
 362
 363                 $this->user = $user;
 364                 $this->metaDirty = true;
 365                 $this->logger->debug(
 366                         'SessionBackend "{session}" metadata dirty due to user change',
 367                         array(
 368                                 'session' => $this->id,
 369                 ) );
 370                 $this->autosave();
 371         }
 372
 373         /**
 374          * Get a suggested username for the login form
 375          * @param int $index Session index
 376          * @return string|null
 377          */
 378         public function suggestLoginUsername( $index ) {
 379                 if ( !isset( $this->requests[$index] ) ) {
 380                         throw new \InvalidArgumentException( 'Invalid session index' );
 381                 }
 382                 return $this->provider->suggestLoginUsername( $this->requests[$index] );
 383         }
 384
 385         /**
 386          * Whether HTTPS should be forced
 387          * @return bool
 388          */
 389         public function shouldForceHTTPS() {
 390                 return $this->forceHTTPS;
 391         }
 392
 393         /**
 394          * Set whether HTTPS should be forced
 395          * @param bool $force
 396          */
 397         public function setForceHTTPS( $force ) {
 398                 if ( $this->forceHTTPS !== (bool)$force ) {
 399                         $this->forceHTTPS = (bool)$force;
 400                         $this->metaDirty = true;
 401                         $this->logger->debug(
 402                                 'SessionBackend "{session}" metadata dirty due to force-HTTPS change',
 403                                 array(
 404                                         'session' => $this->id,
 405                         ) );
 406                         $this->autosave();
 407                 }
 408         }
 409
 410         /**
 411          * Fetch the "logged out" timestamp
 412          * @return int
 413          */
 414         public function getLoggedOutTimestamp() {
 415                 return $this->loggedOut;
 416         }
 417
 418         /**
 419          * Set the "logged out" timestamp
 420          * @param int $ts
 421          */
 422         public function setLoggedOutTimestamp( $ts = null ) {
 423                 $ts = (int)$ts;
 424                 if ( $this->loggedOut !== $ts ) {
 425                         $this->loggedOut = $ts;
 426                         $this->metaDirty = true;
 427                         $this->logger->debug(
 428                                 'SessionBackend "{session}" metadata dirty due to logged-out-timestamp change',
 429                                 array(
 430                                         'session' => $this->id,
 431                         ) );
 432                         $this->autosave();
 433                 }
 434         }
 435
 436         /**
 437          * Fetch provider metadata
 438          * @protected For use by SessionProvider subclasses only
 439          * @return array|null
 440          */
 441         public function getProviderMetadata() {
 442                 return $this->providerMetadata;
 443         }
 444
 445         /**
 446          * Set provider metadata
 447          * @protected For use by SessionProvider subclasses only
 448          * @param array|null $metadata
 449          */
 450         public function setProviderMetadata( $metadata ) {
 451                 if ( $metadata !== null && !is_array( $metadata ) ) {
 452                         throw new \InvalidArgumentException( '$metadata must be an array or null' );
 453                 }
 454                 if ( $this->providerMetadata !== $metadata ) {
 455                         $this->providerMetadata = $metadata;
 456                         $this->metaDirty = true;
 457                         $this->logger->debug(
 458                                 'SessionBackend "{session}" metadata dirty due to provider metadata change',
 459                                 array(
 460                                         'session' => $this->id,
 461                         ) );
 462                         $this->autosave();
 463                 }
 464         }
 465
 466         /**
 467          * Fetch the session data array
 468          *
 469          * Note the caller is responsible for calling $this->dirty() if anything in
 470          * the array is changed.
 471          *
 472          * @private For use by \\MediaWiki\\Session\\Session only.
 473          * @return array
 474          */
 475         public function &getData() {
 476                 return $this->data;
 477         }
 478
 479         /**
 480          * Add data to the session.
 481          *
 482          * Overwrites any existing data under the same keys.
 483          *
 484          * @param array $newData Key-value pairs to add to the session
 485          */
 486         public function addData( array $newData ) {
 487                 $data = &$this->getData();
 488                 foreach ( $newData as $key => $value ) {
 489                         if ( !array_key_exists( $key, $data ) || $data[$key] !== $value ) {
 490                                 $data[$key] = $value;
 491                                 $this->dataDirty = true;
 492                                 $this->logger->debug(
 493                                         'SessionBackend "{session}" data dirty due to addData(): {callers}',
 494                                         array(
 495                                                 'session' => $this->id,
 496                                                 'callers' => wfGetAllCallers( 5 ),
 497                                 ) );
 498                         }
 499                 }
 500         }
 501
 502         /**
 503          * Mark data as dirty
 504          * @private For use by \\MediaWiki\\Session\\Session only.
 505          */
 506         public function dirty() {
 507                 $this->dataDirty = true;
 508                 $this->logger->debug(
 509                         'SessionBackend "{session}" data dirty due to dirty(): {callers}',
 510                         array(
 511                                 'session' => $this->id,
 512                                 'callers' => wfGetAllCallers( 5 ),
 513                 ) );
 514         }
 515
 516         /**
 517          * Renew the session by resaving everything
 518          *
 519          * Resets the TTL in the backend store if the session is near expiring, and
 520          * re-persists the session to any active WebRequests if persistent.
 521          */
 522         public function renew() {
 523                 if ( time() + $this->lifetime / 2 > $this->expires ) {
 524                         $this->metaDirty = true;
 525                         $this->logger->debug(
 526                                 'SessionBackend "{callers}" metadata dirty for renew(): {callers}',
 527                                 array(
 528                                         'session' => $this->id,
 529                                         'callers' => wfGetAllCallers( 5 ),
 530                         ) );
 531                         if ( $this->persist ) {
 532                                 $this->forcePersist = true;
 533                                 $this->logger->debug(
 534                                         'SessionBackend "{session}" force-persist for renew(): {callers}',
 535                                         array(
 536                                                 'session' => $this->id,
 537                                                 'callers' => wfGetAllCallers( 5 ),
 538                                 ) );
 539                         }
 540                 }
 541                 $this->autosave();
 542         }
 543
 544         /**
 545          * Delay automatic saving while multiple updates are being made
 546          *
 547          * Calls to save() will not be delayed.
 548          *
 549          * @return \ScopedCallback When this goes out of scope, a save will be triggered
 550          */
 551         public function delaySave() {
 552                 $that = $this;
 553                 $this->delaySave++;
 554                 $ref = &$this->delaySave;
 555                 return new \ScopedCallback( function () use ( $that, &$ref ) {
 556                         if ( --$ref <= 0 ) {
 557                                 $ref = 0;
 558                                 $that->save();
 559                         }
 560                 } );
 561         }
 562
 563         /**
 564          * Save and persist session data, unless delayed
 565          */
 566         private function autosave() {
 567                 if ( $this->delaySave <= 0 ) {
 568                         $this->save();
 569                 }
 570         }
 571
 572         /**
 573          * Save and persist session data
 574          * @param bool $closing Whether the session is being closed
 575          */
 576         public function save( $closing = false ) {
 577                 if ( $this->provider->getManager()->isUserSessionPrevented( $this->user->getName() ) ) {
 578                         $this->logger->debug(
 579                                 'SessionBackend "{session}" not saving, user {user} was ' .
 580                                 'passed to SessionManager::preventSessionsForUser',
 581                                 array(
 582                                         'session' => $this->id,
 583                                         'user' => $this->user,
 584                         ) );
 585                         return;
 586                 }
 587
 588                 // Ensure the user has a token
 589                 // @codeCoverageIgnoreStart
 590                 $anon = $this->user->isAnon();
 591                 if ( !$anon && !$this->user->getToken( false ) ) {
 592                         $this->logger->debug(
 593                                 'SessionBackend "{session}" creating token for user {user} on save',
 594                                 array(
 595                                         'session' => $this->id,
 596                                         'user' => $this->user,
 597                         ) );
 598                         $this->user->setToken();
 599                         if ( !wfReadOnly() ) {
 600                                 $this->user->saveSettings();
 601                         }
 602                         $this->metaDirty = true;
 603                 }
 604                 // @codeCoverageIgnoreEnd
 605
 606                 if ( !$this->metaDirty && !$this->dataDirty &&
 607                         $this->dataHash !== md5( serialize( $this->data ) )
 608                 ) {
 609                         $this->logger->debug(
 610                                 'SessionBackend "{session}" data dirty due to hash mismatch, {expected} !== {got}',
 611                                 array(
 612                                         'session' => $this->id,
 613                                         'expected' => $this->dataHash,
 614                                         'got' => md5( serialize( $this->data ) ),
 615                         ) );
 616                         $this->dataDirty = true;
 617                 }
 618
 619                 if ( !$this->metaDirty && !$this->dataDirty && !$this->forcePersist ) {
 620                         return;
 621                 }
 622
 623                 $this->logger->debug(
 624                         'SessionBackend "{session}" save: dataDirty={dataDirty} ' .
 625                         'metaDirty={metaDirty} forcePersist={forcePersist}',
 626                         array(
 627                                 'session' => $this->id,
 628                                 'dataDirty' => (int)$this->dataDirty,
 629                                 'metaDirty' => (int)$this->metaDirty,
 630                                 'forcePersist' => (int)$this->forcePersist,
 631                 ) );
 632
 633                 // Persist to the provider, if flagged
 634                 if ( $this->persist && ( $this->metaDirty || $this->forcePersist ) ) {
 635                         foreach ( $this->requests as $request ) {
 636                                 $request->setSessionId( $this->getSessionId() );
 637                                 $this->provider->persistSession( $this, $request );
 638                         }
 639                         if ( !$closing ) {
 640                                 $this->checkPHPSession();
 641                         }
 642                 }
 643
 644                 $this->forcePersist = false;
 645
 646                 if ( !$this->metaDirty && !$this->dataDirty ) {
 647                         return;
 648                 }
 649
 650                 // Save session data to store, if necessary
 651                 $metadata = $origMetadata = array(
 652                         'provider' => (string)$this->provider,
 653                         'providerMetadata' => $this->providerMetadata,
 654                         'userId' => $anon ? 0 : $this->user->getId(),
 655                         'userName' => User::isValidUserName( $this->user->getName() ) ? $this->user->getName() : null,
 656                         'userToken' => $anon ? null : $this->user->getToken(),
 657                         'remember' => !$anon && $this->remember,
 658                         'forceHTTPS' => $this->forceHTTPS,
 659                         'expires' => time() + $this->lifetime,
 660                         'loggedOut' => $this->loggedOut,
 661                         'persisted' => $this->persist,
 662                 );
 663
 664                 \Hooks::run( 'SessionMetadata', array( $this, &$metadata, $this->requests ) );
 665
 666                 foreach ( $origMetadata as $k => $v ) {
 667                         if ( $metadata[$k] !== $v ) {
 668                                 throw new \UnexpectedValueException( "SessionMetadata hook changed metadata key \"$k\"" );
 669                         }
 670                 }
 671
 672                 $this->store->set(
 673                         wfMemcKey( 'MWSession', (string)$this->id ),
 674                         array(
 675                                 'data' => $this->data,
 676                                 'metadata' => $metadata,
 677                         ),
 678                         $metadata['expires'],
 679                         $this->persist ? 0 : CachedBagOStuff::WRITE_CACHE_ONLY
 680                 );
 681
 682                 $this->metaDirty = false;
 683                 $this->dataDirty = false;
 684                 $this->dataHash = md5( serialize( $this->data ) );
 685                 $this->expires = $metadata['expires'];
 686         }
 687
 688         /**
 689          * For backwards compatibility, open the PHP session when the global
 690          * session is persisted
 691          */
 692         private function checkPHPSession() {
 693                 if ( !$this->checkPHPSessionRecursionGuard ) {
 694                         $this->checkPHPSessionRecursionGuard = true;
 695                         $ref = &$this->checkPHPSessionRecursionGuard;
 696                         $reset = new \ScopedCallback( function () use ( &$ref ) {
 697                                 $ref = false;
 698                         } );
 699
 700                         if ( $this->usePhpSessionHandling && session_id() === '' && PHPSessionHandler::isEnabled() &&
 701                                 SessionManager::getGlobalSession()->getId() === (string)$this->id
 702                         ) {
 703                                 $this->logger->debug(
 704                                         'SessionBackend "{session}" Taking over PHP session',
 705                                         array(
 706                                                 'session' => $this->id,
 707                                 ) );
 708                                 session_id( (string)$this->id );
 709                                 \MediaWiki\quietCall( 'session_start' );
 710                         }
 711                 }
 712         }
 713
 714 }