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( "SessionBackend $this->id is unsaved, marking dirty in constructor" );
 142                 } else {
 143                         $this->data = $blob['data'];
 144                         if ( isset( $blob['metadata']['loggedOut'] ) ) {
 145                                 $this->loggedOut = (int)$blob['metadata']['loggedOut'];
 146                         }
 147                         if ( isset( $blob['metadata']['expires'] ) ) {
 148                                 $this->expires = (int)$blob['metadata']['expires'];
 149                         } else {
 150                                 $this->metaDirty = true;
 151                                 $this->logger->debug(
 152                                         "SessionBackend $this->id metadata dirty due to missing expiration timestamp"
 153                                 );
 154                         }
 155                 }
 156                 $this->dataHash = md5( serialize( $this->data ) );
 157         }
 158
 159         /**
 160          * Return a new Session for this backend
 161          * @param WebRequest $request
 162          * @return Session
 163          */
 164         public function getSession( WebRequest $request ) {
 165                 $index = ++$this->curIndex;
 166                 $this->requests[$index] = $request;
 167                 $session = new Session( $this, $index );
 168                 return $session;
 169         }
 170
 171         /**
 172          * Deregister a Session
 173          * @private For use by \\MediaWiki\\Session\\Session::__destruct() only
 174          * @param int $index
 175          */
 176         public function deregisterSession( $index ) {
 177                 unset( $this->requests[$index] );
 178                 if ( !count( $this->requests ) ) {
 179                         $this->save( true );
 180                         $this->provider->getManager()->deregisterSessionBackend( $this );
 181                 }
 182         }
 183
 184         /**
 185          * Returns the session ID.
 186          * @return string
 187          */
 188         public function getId() {
 189                 return (string)$this->id;
 190         }
 191
 192         /**
 193          * Fetch the SessionId object
 194          * @private For internal use by WebRequest
 195          * @return SessionId
 196          */
 197         public function getSessionId() {
 198                 return $this->id;
 199         }
 200
 201         /**
 202          * Changes the session ID
 203          * @return string New ID (might be the same as the old)
 204          */
 205         public function resetId() {
 206                 if ( $this->provider->persistsSessionId() ) {
 207                         $oldId = (string)$this->id;
 208                         $restart = $this->usePhpSessionHandling && $oldId === session_id() &&
 209                                 PHPSessionHandler::isEnabled();
 210
 211                         if ( $restart ) {
 212                                 // If this session is the one behind PHP's $_SESSION, we need
 213                                 // to close then reopen it.
 214                                 session_write_close();
 215                         }
 216
 217                         $this->provider->getManager()->changeBackendId( $this );
 218                         $this->provider->sessionIdWasReset( $this, $oldId );
 219                         $this->metaDirty = true;
 220                         $this->logger->debug(
 221                                 "SessionBackend $this->id metadata dirty due to ID reset (formerly $oldId)"
 222                         );
 223
 224                         if ( $restart ) {
 225                                 session_id( (string)$this->id );
 226                                 \MediaWiki\quietCall( 'session_start' );
 227                         }
 228
 229                         $this->autosave();
 230
 231                         // Delete the data for the old session ID now
 232                         $this->store->delete( wfMemcKey( 'MWSession', $oldId ) );
 233                 }
 234         }
 235
 236         /**
 237          * Fetch the SessionProvider for this session
 238          * @return SessionProviderInterface
 239          */
 240         public function getProvider() {
 241                 return $this->provider;
 242         }
 243
 244         /**
 245          * Indicate whether this session is persisted across requests
 246          *
 247          * For example, if cookies are set.
 248          *
 249          * @return bool
 250          */
 251         public function isPersistent() {
 252                 return $this->persist;
 253         }
 254
 255         /**
 256          * Make this session persisted across requests
 257          *
 258          * If the session is already persistent, equivalent to calling
 259          * $this->renew().
 260          */
 261         public function persist() {
 262                 if ( !$this->persist ) {
 263                         $this->persist = true;
 264                         $this->forcePersist = true;
 265                         $this->metaDirty = true;
 266                         $this->logger->debug( "SessionBackend $this->id force-persist due to persist()" );
 267                         $this->autosave();
 268                 } else {
 269                         $this->renew();
 270                 }
 271         }
 272
 273         /**
 274          * Indicate whether the user should be remembered independently of the
 275          * session ID.
 276          * @return bool
 277          */
 278         public function shouldRememberUser() {
 279                 return $this->remember;
 280         }
 281
 282         /**
 283          * Set whether the user should be remembered independently of the session
 284          * ID.
 285          * @param bool $remember
 286          */
 287         public function setRememberUser( $remember ) {
 288                 if ( $this->remember !== (bool)$remember ) {
 289                         $this->remember = (bool)$remember;
 290                         $this->metaDirty = true;
 291                         $this->logger->debug( "SessionBackend $this->id metadata dirty due to remember-user change" );
 292                         $this->autosave();
 293                 }
 294         }
 295
 296         /**
 297          * Returns the request associated with a Session
 298          * @param int $index Session index
 299          * @return WebRequest
 300          */
 301         public function getRequest( $index ) {
 302                 if ( !isset( $this->requests[$index] ) ) {
 303                         throw new \InvalidArgumentException( 'Invalid session index' );
 304                 }
 305                 return $this->requests[$index];
 306         }
 307
 308         /**
 309          * Returns the authenticated user for this session
 310          * @return User
 311          */
 312         public function getUser() {
 313                 return $this->user;
 314         }
 315
 316         /**
 317          * Fetch the rights allowed the user when this session is active.
 318          * @return null|string[] Allowed user rights, or null to allow all.
 319          */
 320         public function getAllowedUserRights() {
 321                 return $this->provider->getAllowedUserRights( $this );
 322         }
 323
 324         /**
 325          * Indicate whether the session user info can be changed
 326          * @return bool
 327          */
 328         public function canSetUser() {
 329                 return $this->provider->canChangeUser();
 330         }
 331
 332         /**
 333          * Set a new user for this session
 334          * @note This should only be called when the user has been authenticated via a login process
 335          * @param User $user User to set on the session.
 336          *   This may become a "UserValue" in the future, or User may be refactored
 337          *   into such.
 338          */
 339         public function setUser( $user ) {
 340                 if ( !$this->canSetUser() ) {
 341                         throw new \BadMethodCallException(
 342                                 'Cannot set user on this session; check $session->canSetUser() first'
 343                         );
 344                 }
 345
 346                 $this->user = $user;
 347                 $this->metaDirty = true;
 348                 $this->logger->debug( "SessionBackend $this->id metadata dirty due to user change" );
 349                 $this->autosave();
 350         }
 351
 352         /**
 353          * Get a suggested username for the login form
 354          * @param int $index Session index
 355          * @return string|null
 356          */
 357         public function suggestLoginUsername( $index ) {
 358                 if ( !isset( $this->requests[$index] ) ) {
 359                         throw new \InvalidArgumentException( 'Invalid session index' );
 360                 }
 361                 return $this->provider->suggestLoginUsername( $this->requests[$index] );
 362         }
 363
 364         /**
 365          * Whether HTTPS should be forced
 366          * @return bool
 367          */
 368         public function shouldForceHTTPS() {
 369                 return $this->forceHTTPS;
 370         }
 371
 372         /**
 373          * Set whether HTTPS should be forced
 374          * @param bool $force
 375          */
 376         public function setForceHTTPS( $force ) {
 377                 if ( $this->forceHTTPS !== (bool)$force ) {
 378                         $this->forceHTTPS = (bool)$force;
 379                         $this->metaDirty = true;
 380                         $this->logger->debug( "SessionBackend $this->id metadata dirty due to force-HTTPS change" );
 381                         $this->autosave();
 382                 }
 383         }
 384
 385         /**
 386          * Fetch the "logged out" timestamp
 387          * @return int
 388          */
 389         public function getLoggedOutTimestamp() {
 390                 return $this->loggedOut;
 391         }
 392
 393         /**
 394          * Set the "logged out" timestamp
 395          * @param int $ts
 396          */
 397         public function setLoggedOutTimestamp( $ts = null ) {
 398                 $ts = (int)$ts;
 399                 if ( $this->loggedOut !== $ts ) {
 400                         $this->loggedOut = $ts;
 401                         $this->metaDirty = true;
 402                         $this->logger->debug(
 403                                 "SessionBackend $this->id metadata dirty due to logged-out-timestamp change"
 404                         );
 405                         $this->autosave();
 406                 }
 407         }
 408
 409         /**
 410          * Fetch provider metadata
 411          * @protected For use by SessionProvider subclasses only
 412          * @return array|null
 413          */
 414         public function getProviderMetadata() {
 415                 return $this->providerMetadata;
 416         }
 417
 418         /**
 419          * Set provider metadata
 420          * @protected For use by SessionProvider subclasses only
 421          * @param array|null $metadata
 422          */
 423         public function setProviderMetadata( $metadata ) {
 424                 if ( $metadata !== null && !is_array( $metadata ) ) {
 425                         throw new \InvalidArgumentException( '$metadata must be an array or null' );
 426                 }
 427                 if ( $this->providerMetadata !== $metadata ) {
 428                         $this->providerMetadata = $metadata;
 429                         $this->metaDirty = true;
 430                         $this->logger->debug(
 431                                 "SessionBackend $this->id metadata dirty due to provider metadata change"
 432                         );
 433                         $this->autosave();
 434                 }
 435         }
 436
 437         /**
 438          * Fetch the session data array
 439          *
 440          * Note the caller is responsible for calling $this->dirty() if anything in
 441          * the array is changed.
 442          *
 443          * @private For use by \\MediaWiki\\Session\\Session only.
 444          * @return array
 445          */
 446         public function &getData() {
 447                 return $this->data;
 448         }
 449
 450         /**
 451          * Add data to the session.
 452          *
 453          * Overwrites any existing data under the same keys.
 454          *
 455          * @param array $newData Key-value pairs to add to the session
 456          */
 457         public function addData( array $newData ) {
 458                 $data = &$this->getData();
 459                 foreach ( $newData as $key => $value ) {
 460                         if ( !array_key_exists( $key, $data ) || $data[$key] !== $value ) {
 461                                 $data[$key] = $value;
 462                                 $this->dataDirty = true;
 463                                 $this->logger->debug(
 464                                         "SessionBackend $this->id data dirty due to addData(): " . wfGetAllCallers( 5 )
 465                                 );
 466                         }
 467                 }
 468         }
 469
 470         /**
 471          * Mark data as dirty
 472          * @private For use by \\MediaWiki\\Session\\Session only.
 473          */
 474         public function dirty() {
 475                 $this->dataDirty = true;
 476                 $this->logger->debug(
 477                         "SessionBackend $this->id data dirty due to dirty(): " . wfGetAllCallers( 5 )
 478                 );
 479         }
 480
 481         /**
 482          * Renew the session by resaving everything
 483          *
 484          * Resets the TTL in the backend store if the session is near expiring, and
 485          * re-persists the session to any active WebRequests if persistent.
 486          */
 487         public function renew() {
 488                 if ( time() + $this->lifetime / 2 > $this->expires ) {
 489                         $this->metaDirty = true;
 490                         $this->logger->debug(
 491                                 "SessionBackend $this->id metadata dirty for renew(): " . wfGetAllCallers( 5 )
 492                         );
 493                         if ( $this->persist ) {
 494                                 $this->forcePersist = true;
 495                                 $this->logger->debug(
 496                                         "SessionBackend $this->id force-persist for renew(): " . wfGetAllCallers( 5 )
 497                                 );
 498                         }
 499                 }
 500                 $this->autosave();
 501         }
 502
 503         /**
 504          * Delay automatic saving while multiple updates are being made
 505          *
 506          * Calls to save() will not be delayed.
 507          *
 508          * @return \ScopedCallback When this goes out of scope, a save will be triggered
 509          */
 510         public function delaySave() {
 511                 $that = $this;
 512                 $this->delaySave++;
 513                 $ref = &$this->delaySave;
 514                 return new \ScopedCallback( function () use ( $that, &$ref ) {
 515                         if ( --$ref <= 0 ) {
 516                                 $ref = 0;
 517                                 $that->save();
 518                         }
 519                 } );
 520         }
 521
 522         /**
 523          * Save and persist session data, unless delayed
 524          */
 525         private function autosave() {
 526                 if ( $this->delaySave <= 0 ) {
 527                         $this->save();
 528                 }
 529         }
 530
 531         /**
 532          * Save and persist session data
 533          * @param bool $closing Whether the session is being closed
 534          */
 535         public function save( $closing = false ) {
 536                 if ( $this->provider->getManager()->isUserSessionPrevented( $this->user->getName() ) ) {
 537                         $this->logger->debug(
 538                                 "SessionBackend $this->id not saving, " .
 539                                         "user {$this->user} was passed to SessionManager::preventSessionsForUser"
 540                         );
 541                         return;
 542                 }
 543
 544                 // Ensure the user has a token
 545                 // @codeCoverageIgnoreStart
 546                 $anon = $this->user->isAnon();
 547                 if ( !$anon && !$this->user->getToken( false ) ) {
 548                         $this->logger->debug(
 549                                 "SessionBackend $this->id creating token for user {$this->user} on save"
 550                         );
 551                         $this->user->setToken();
 552                         if ( !wfReadOnly() ) {
 553                                 $this->user->saveSettings();
 554                         }
 555                         $this->metaDirty = true;
 556                 }
 557                 // @codeCoverageIgnoreEnd
 558
 559                 if ( !$this->metaDirty && !$this->dataDirty &&
 560                         $this->dataHash !== md5( serialize( $this->data ) )
 561                 ) {
 562                         $this->logger->debug( "SessionBackend $this->id data dirty due to hash mismatch, " .
 563                                 "$this->dataHash !== " . md5( serialize( $this->data ) ) );
 564                         $this->dataDirty = true;
 565                 }
 566
 567                 if ( !$this->metaDirty && !$this->dataDirty && !$this->forcePersist ) {
 568                         return;
 569                 }
 570
 571                 $this->logger->debug( "SessionBackend $this->id save: " .
 572                         'dataDirty=' . (int)$this->dataDirty . ' ' .
 573                         'metaDirty=' . (int)$this->metaDirty . ' ' .
 574                         'forcePersist=' . (int)$this->forcePersist
 575                 );
 576
 577                 // Persist to the provider, if flagged
 578                 if ( $this->persist && ( $this->metaDirty || $this->forcePersist ) ) {
 579                         foreach ( $this->requests as $request ) {
 580                                 $request->setSessionId( $this->getSessionId() );
 581                                 $this->provider->persistSession( $this, $request );
 582                         }
 583                         if ( !$closing ) {
 584                                 $this->checkPHPSession();
 585                         }
 586                 }
 587
 588                 $this->forcePersist = false;
 589
 590                 if ( !$this->metaDirty && !$this->dataDirty ) {
 591                         return;
 592                 }
 593
 594                 // Save session data to store, if necessary
 595                 $metadata = $origMetadata = array(
 596                         'provider' => (string)$this->provider,
 597                         'providerMetadata' => $this->providerMetadata,
 598                         'userId' => $anon ? 0 : $this->user->getId(),
 599                         'userName' => User::isValidUserName( $this->user->getName() ) ? $this->user->getName() : null,
 600                         'userToken' => $anon ? null : $this->user->getToken(),
 601                         'remember' => !$anon && $this->remember,
 602                         'forceHTTPS' => $this->forceHTTPS,
 603                         'expires' => time() + $this->lifetime,
 604                         'loggedOut' => $this->loggedOut,
 605                         'persisted' => $this->persist,
 606                 );
 607
 608                 \Hooks::run( 'SessionMetadata', array( $this, &$metadata, $this->requests ) );
 609
 610                 foreach ( $origMetadata as $k => $v ) {
 611                         if ( $metadata[$k] !== $v ) {
 612                                 throw new \UnexpectedValueException( "SessionMetadata hook changed metadata key \"$k\"" );
 613                         }
 614                 }
 615
 616                 $this->store->set(
 617                         wfMemcKey( 'MWSession', (string)$this->id ),
 618                         array(
 619                                 'data' => $this->data,
 620                                 'metadata' => $metadata,
 621                         ),
 622                         $metadata['expires'],
 623                         $this->persist ? 0 : CachedBagOStuff::WRITE_CACHE_ONLY
 624                 );
 625
 626                 $this->metaDirty = false;
 627                 $this->dataDirty = false;
 628                 $this->dataHash = md5( serialize( $this->data ) );
 629                 $this->expires = $metadata['expires'];
 630         }
 631
 632         /**
 633          * For backwards compatibility, open the PHP session when the global
 634          * session is persisted
 635          */
 636         private function checkPHPSession() {
 637                 if ( !$this->checkPHPSessionRecursionGuard ) {
 638                         $this->checkPHPSessionRecursionGuard = true;
 639                         $ref = &$this->checkPHPSessionRecursionGuard;
 640                         $reset = new \ScopedCallback( function () use ( &$ref ) {
 641                                 $ref = false;
 642                         } );
 643
 644                         if ( $this->usePhpSessionHandling && session_id() === '' && PHPSessionHandler::isEnabled() &&
 645                                 SessionManager::getGlobalSession()->getId() === (string)$this->id
 646                         ) {
 647                                 $this->logger->debug( "SessionBackend $this->id: Taking over PHP session" );
 648                                 session_id( (string)$this->id );
 649                                 \MediaWiki\quietCall( 'session_start' );
 650                         }
 651                 }
 652         }
 653
 654 }