includes/block/BlockManager.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 namespace MediaWiki\Block;
  22
  23 use DateTime;
  24 use DateTimeZone;
  25 use DeferredUpdates;
  26 use IP;
  27 use MediaWiki\Config\ServiceOptions;
  28 use MediaWiki\User\UserIdentity;
  29 use MWCryptHash;
  30 use User;
  31 use WebRequest;
  32 use WebResponse;
  33 use Wikimedia\IPSet;
  34
  35 /**
  36  * A service class for checking blocks.
  37  * To obtain an instance, use MediaWikiServices::getInstance()->getBlockManager().
  38  *
  39  * @since 1.34 Refactored from User and Block.
  40  */
  41 class BlockManager {
  42         // TODO: This should be UserIdentity instead of User
  43         /** @var User */
  44         private $currentUser;
  45
  46         /** @var WebRequest */
  47         private $currentRequest;
  48
  49         /**
  50          * TODO Make this a const when HHVM support is dropped (T192166)
  51          *
  52          * @var array
  53          * @since 1.34
  54          */
  55         public static $constructorOptions = [
  56                 'ApplyIpBlocksToXff',
  57                 'CookieSetOnAutoblock',
  58                 'CookieSetOnIpBlock',
  59                 'DnsBlacklistUrls',
  60                 'EnableDnsBlacklist',
  61                 'ProxyList',
  62                 'ProxyWhitelist',
  63                 'SecretKey',
  64                 'SoftBlockRanges',
  65         ];
  66
  67         /**
  68          * @param ServiceOptions $options
  69          * @param User $currentUser
  70          * @param WebRequest $currentRequest
  71          */
  72         public function __construct(
  73                 ServiceOptions $options,
  74                 User $currentUser,
  75                 WebRequest $currentRequest
  76         ) {
  77                 $options->assertRequiredOptions( self::$constructorOptions );
  78                 $this->options = $options;
  79                 $this->currentUser = $currentUser;
  80                 $this->currentRequest = $currentRequest;
  81         }
  82
  83         /**
  84          * Get the blocks that apply to a user. If there is only one, return that, otherwise
  85          * return a composite block that combines the strictest features of the applicable
  86          * blocks.
  87          *
  88          * TODO: $user should be UserIdentity instead of User
  89          *
  90          * @internal This should only be called by User::getBlockedStatus
  91          * @param User $user
  92          * @param bool $fromReplica Whether to check the replica DB first.
  93          *  To improve performance, non-critical checks are done against replica DBs.
  94          *  Check when actually saving should be done against master.
  95          * @return AbstractBlock|null The most relevant block, or null if there is no block.
  96          */
  97         public function getUserBlock( User $user, $fromReplica ) {
  98                 $isAnon = $user->getId() === 0;
  99
 100                 // TODO: If $user is the current user, we should use the current request. Otherwise,
 101                 // we should not look for XFF or cookie blocks.
 102                 $request = $user->getRequest();
 103
 104                 # We only need to worry about passing the IP address to the block generator if the
 105                 # user is not immune to autoblocks/hardblocks, and they are the current user so we
 106                 # know which IP address they're actually coming from
 107                 $ip = null;
 108                 $sessionUser = $this->currentUser;
 109                 // the session user is set up towards the end of Setup.php. Until then,
 110                 // assume it's a logged-out user.
 111                 $globalUserName = $sessionUser->isSafeToLoad()
 112                         ? $sessionUser->getName()
 113                         : IP::sanitizeIP( $this->currentRequest->getIP() );
 114                 if ( $user->getName() === $globalUserName && !$user->isAllowed( 'ipblock-exempt' ) ) {
 115                         $ip = $this->currentRequest->getIP();
 116                 }
 117
 118                 // User/IP blocking
 119                 // After this, $blocks is an array of blocks or an empty array
 120                 // TODO: remove dependency on DatabaseBlock
 121                 $blocks = DatabaseBlock::newListFromTarget( $user, $ip, !$fromReplica );
 122
 123                 // Cookie blocking
 124                 $cookieBlock = $this->getBlockFromCookieValue( $user, $request );
 125                 if ( $cookieBlock instanceof AbstractBlock ) {
 126                         $blocks[] = $cookieBlock;
 127                 }
 128
 129                 // Proxy blocking
 130                 if ( $ip !== null && !in_array( $ip, $this->options->get( 'ProxyWhitelist' ) ) ) {
 131                         // Local list
 132                         if ( $this->isLocallyBlockedProxy( $ip ) ) {
 133                                 $blocks[] = new SystemBlock( [
 134                                         'byText' => wfMessage( 'proxyblocker' )->text(),
 135                                         'reason' => wfMessage( 'proxyblockreason' )->plain(),
 136                                         'address' => $ip,
 137                                         'systemBlock' => 'proxy',
 138                                 ] );
 139                         } elseif ( $isAnon && $this->isDnsBlacklisted( $ip ) ) {
 140                                 $blocks[] = new SystemBlock( [
 141                                         'byText' => wfMessage( 'sorbs' )->text(),
 142                                         'reason' => wfMessage( 'sorbsreason' )->plain(),
 143                                         'address' => $ip,
 144                                         'systemBlock' => 'dnsbl',
 145                                 ] );
 146                         }
 147                 }
 148
 149                 // (T25343) Apply IP blocks to the contents of XFF headers, if enabled
 150                 if ( $this->options->get( 'ApplyIpBlocksToXff' )
 151                         && $ip !== null
 152                         && !in_array( $ip, $this->options->get( 'ProxyWhitelist' ) )
 153                 ) {
 154                         $xff = $request->getHeader( 'X-Forwarded-For' );
 155                         $xff = array_map( 'trim', explode( ',', $xff ) );
 156                         $xff = array_diff( $xff, [ $ip ] );
 157                         // TODO: remove dependency on DatabaseBlock
 158                         $xffblocks = DatabaseBlock::getBlocksForIPList( $xff, $isAnon, !$fromReplica );
 159                         $blocks = array_merge( $blocks, $xffblocks );
 160                 }
 161
 162                 // Soft blocking
 163                 if ( $ip !== null
 164                         && $isAnon
 165                         && IP::isInRanges( $ip, $this->options->get( 'SoftBlockRanges' ) )
 166                 ) {
 167                         $blocks[] = new SystemBlock( [
 168                                 'address' => $ip,
 169                                 'byText' => 'MediaWiki default',
 170                                 'reason' => wfMessage( 'softblockrangesreason', $ip )->plain(),
 171                                 'anonOnly' => true,
 172                                 'systemBlock' => 'wgSoftBlockRanges',
 173                         ] );
 174                 }
 175
 176                 // Filter out any duplicated blocks, e.g. from the cookie
 177                 $blocks = $this->getUniqueBlocks( $blocks );
 178
 179                 if ( count( $blocks ) > 0 ) {
 180                         if ( count( $blocks ) === 1 ) {
 181                                 $block = $blocks[ 0 ];
 182                         } else {
 183                                 $block = new CompositeBlock( [
 184                                         'address' => $ip,
 185                                         'byText' => 'MediaWiki default',
 186                                         'reason' => wfMessage( 'blockedtext-composite-reason' )->plain(),
 187                                         'originalBlocks' => $blocks,
 188                                 ] );
 189                         }
 190                         return $block;
 191                 }
 192
 193                 return null;
 194         }
 195
 196         /**
 197          * Given a list of blocks, return a list of unique blocks.
 198          *
 199          * This usually means that each block has a unique ID. For a block with ID null,
 200          * if it's an autoblock, it will be filtered out if the parent block is present;
 201          * if not, it is assumed to be a unique system block, and kept.
 202          *
 203          * @param AbstractBlock[] $blocks
 204          * @return AbstractBlock[]
 205          */
 206         private function getUniqueBlocks( array $blocks ) {
 207                 $systemBlocks = [];
 208                 $databaseBlocks = [];
 209
 210                 foreach ( $blocks as $block ) {
 211                         if ( $block instanceof SystemBlock ) {
 212                                 $systemBlocks[] = $block;
 213                         } elseif ( $block->getType() === DatabaseBlock::TYPE_AUTO ) {
 214                                 if ( !isset( $databaseBlocks[$block->getParentBlockId()] ) ) {
 215                                         $databaseBlocks[$block->getParentBlockId()] = $block;
 216                                 }
 217                         } else {
 218                                 $databaseBlocks[$block->getId()] = $block;
 219                         }
 220                 }
 221
 222                 return array_merge( $systemBlocks, $databaseBlocks );
 223         }
 224
 225         /**
 226          * Try to load a block from an ID given in a cookie value. If the block is invalid
 227          * or doesn't exist, remove the cookie.
 228          *
 229          * @param UserIdentity $user
 230          * @param WebRequest $request
 231          * @return DatabaseBlock|bool The block object, or false if none could be loaded.
 232          */
 233         private function getBlockFromCookieValue(
 234                 UserIdentity $user,
 235                 WebRequest $request
 236         ) {
 237                 $blockCookieId = $this->getIdFromCookieValue( $request->getCookie( 'BlockID' ) );
 238
 239                 if ( $blockCookieId !== null ) {
 240                         // TODO: remove dependency on DatabaseBlock
 241                         $block = DatabaseBlock::newFromID( $blockCookieId );
 242                         if (
 243                                 $block instanceof DatabaseBlock &&
 244                                 $this->shouldApplyCookieBlock( $block, $user->isAnon() )
 245                         ) {
 246                                 return $block;
 247                         }
 248                         $this->clearBlockCookie( $request->response() );
 249                 }
 250
 251                 return false;
 252         }
 253
 254         /**
 255          * Check if the block loaded from the cookie should be applied.
 256          *
 257          * @param DatabaseBlock $block
 258          * @param bool $isAnon The user is logged out
 259          * @return bool The block sould be applied
 260          */
 261         private function shouldApplyCookieBlock( DatabaseBlock $block, $isAnon ) {
 262                 if ( !$block->isExpired() ) {
 263                         switch ( $block->getType() ) {
 264                                 case DatabaseBlock::TYPE_IP:
 265                                 case DatabaseBlock::TYPE_RANGE:
 266                                         // If block is type IP or IP range, load only
 267                                         // if user is not logged in (T152462)
 268                                         return $isAnon &&
 269                                                 $this->options->get( 'CookieSetOnIpBlock' );
 270                                 case DatabaseBlock::TYPE_USER:
 271                                         return $block->isAutoblocking() &&
 272                                                 $this->options->get( 'CookieSetOnAutoblock' );
 273                                 default:
 274                                         return false;
 275                         }
 276                 }
 277                 return false;
 278         }
 279
 280         /**
 281          * Check if an IP address is in the local proxy list
 282          *
 283          * @param string $ip
 284          * @return bool
 285          */
 286         private function isLocallyBlockedProxy( $ip ) {
 287                 $proxyList = $this->options->get( 'ProxyList' );
 288                 if ( !$proxyList ) {
 289                         return false;
 290                 }
 291
 292                 if ( !is_array( $proxyList ) ) {
 293                         // Load values from the specified file
 294                         $proxyList = array_map( 'trim', file( $proxyList ) );
 295                 }
 296
 297                 $proxyListIPSet = new IPSet( $proxyList );
 298                 return $proxyListIPSet->match( $ip );
 299         }
 300
 301         /**
 302          * Whether the given IP is in a DNS blacklist.
 303          *
 304          * @param string $ip IP to check
 305          * @param bool $checkWhitelist Whether to check the whitelist first
 306          * @return bool True if blacklisted.
 307          */
 308         public function isDnsBlacklisted( $ip, $checkWhitelist = false ) {
 309                 if ( !$this->options->get( 'EnableDnsBlacklist' ) ||
 310                         ( $checkWhitelist && in_array( $ip, $this->options->get( 'ProxyWhitelist' ) ) )
 311                 ) {
 312                         return false;
 313                 }
 314
 315                 return $this->inDnsBlacklist( $ip, $this->options->get( 'DnsBlacklistUrls' ) );
 316         }
 317
 318         /**
 319          * Whether the given IP is in a given DNS blacklist.
 320          *
 321          * @param string $ip IP to check
 322          * @param array $bases Array of Strings: URL of the DNS blacklist
 323          * @return bool True if blacklisted.
 324          */
 325         private function inDnsBlacklist( $ip, array $bases ) {
 326                 $found = false;
 327                 // @todo FIXME: IPv6 ???  (https://bugs.php.net/bug.php?id=33170)
 328                 if ( IP::isIPv4( $ip ) ) {
 329                         // Reverse IP, T23255
 330                         $ipReversed = implode( '.', array_reverse( explode( '.', $ip ) ) );
 331
 332                         foreach ( $bases as $base ) {
 333                                 // Make hostname
 334                                 // If we have an access key, use that too (ProjectHoneypot, etc.)
 335                                 $basename = $base;
 336                                 if ( is_array( $base ) ) {
 337                                         if ( count( $base ) >= 2 ) {
 338                                                 // Access key is 1, base URL is 0
 339                                                 $hostname = "{$base[1]}.$ipReversed.{$base[0]}";
 340                                         } else {
 341                                                 $hostname = "$ipReversed.{$base[0]}";
 342                                         }
 343                                         $basename = $base[0];
 344                                 } else {
 345                                         $hostname = "$ipReversed.$base";
 346                                 }
 347
 348                                 // Send query
 349                                 $ipList = $this->checkHost( $hostname );
 350
 351                                 if ( $ipList ) {
 352                                         wfDebugLog(
 353                                                 'dnsblacklist',
 354                                                 "Hostname $hostname is {$ipList[0]}, it's a proxy says $basename!"
 355                                         );
 356                                         $found = true;
 357                                         break;
 358                                 }
 359
 360                                 wfDebugLog( 'dnsblacklist', "Requested $hostname, not found in $basename." );
 361                         }
 362                 }
 363
 364                 return $found;
 365         }
 366
 367         /**
 368          * Wrapper for mocking in tests.
 369          *
 370          * @param string $hostname DNSBL query
 371          * @return string[]|bool IPv4 array, or false if the IP is not blacklisted
 372          */
 373         protected function checkHost( $hostname ) {
 374                 return gethostbynamel( $hostname );
 375         }
 376
 377         /**
 378          * Set the 'BlockID' cookie depending on block type and user authentication status.
 379          *
 380          * @since 1.34
 381          * @param User $user
 382          */
 383         public function trackBlockWithCookie( User $user ) {
 384                 $request = $user->getRequest();
 385                 if ( $request->getCookie( 'BlockID' ) !== null ) {
 386                         // User already has a block cookie
 387                         return;
 388                 }
 389
 390                 // Defer checks until the user has been fully loaded to avoid circular dependency
 391                 // of User on itself (T180050 and T226777)
 392                 DeferredUpdates::addCallableUpdate(
 393                         function () use ( $user, $request ) {
 394                                 $block = $user->getBlock();
 395                                 $response = $request->response();
 396                                 $isAnon = $user->isAnon();
 397
 398                                 if ( $block ) {
 399                                         if ( $block instanceof CompositeBlock ) {
 400                                                 // TODO: Improve on simply tracking the first trackable block (T225654)
 401                                                 foreach ( $block->getOriginalBlocks() as $originalBlock ) {
 402                                                         if ( $this->shouldTrackBlockWithCookie( $originalBlock, $isAnon ) ) {
 403                                                                 $this->setBlockCookie( $originalBlock, $response );
 404                                                                 return;
 405                                                         }
 406                                                 }
 407                                         } else {
 408                                                 if ( $this->shouldTrackBlockWithCookie( $block, $isAnon ) ) {
 409                                                         $this->setBlockCookie( $block, $response );
 410                                                 }
 411                                         }
 412                                 }
 413                         },
 414                         DeferredUpdates::PRESEND
 415                 );
 416         }
 417
 418         /**
 419          * Set the 'BlockID' cookie to this block's ID and expiry time. The cookie's expiry will be
 420          * the same as the block's, to a maximum of 24 hours.
 421          *
 422          * @since 1.34
 423          * @internal Should be private.
 424          *  Left public for backwards compatibility, until DatabaseBlock::setCookie is removed.
 425          * @param DatabaseBlock $block
 426          * @param WebResponse $response The response on which to set the cookie.
 427          */
 428         public function setBlockCookie( DatabaseBlock $block, WebResponse $response ) {
 429                 // Calculate the default expiry time.
 430                 $maxExpiryTime = wfTimestamp( TS_MW, wfTimestamp() + ( 24 * 60 * 60 ) );
 431
 432                 // Use the block's expiry time only if it's less than the default.
 433                 $expiryTime = $block->getExpiry();
 434                 if ( $expiryTime === 'infinity' || $expiryTime > $maxExpiryTime ) {
 435                         $expiryTime = $maxExpiryTime;
 436                 }
 437
 438                 // Set the cookie. Reformat the MediaWiki datetime as a Unix timestamp for the cookie.
 439                 $expiryValue = DateTime::createFromFormat(
 440                         'YmdHis',
 441                         $expiryTime,
 442                         new DateTimeZone( 'UTC' )
 443                 )->format( 'U' );
 444                 $cookieOptions = [ 'httpOnly' => false ];
 445                 $cookieValue = $this->getCookieValue( $block );
 446                 $response->setCookie( 'BlockID', $cookieValue, $expiryValue, $cookieOptions );
 447         }
 448
 449         /**
 450          * Check if the block should be tracked with a cookie.
 451          *
 452          * @param AbstractBlock $block
 453          * @param bool $isAnon The user is logged out
 454          * @return bool The block sould be tracked with a cookie
 455          */
 456         private function shouldTrackBlockWithCookie( AbstractBlock $block, $isAnon ) {
 457                 if ( $block instanceof DatabaseBlock ) {
 458                         switch ( $block->getType() ) {
 459                                 case DatabaseBlock::TYPE_IP:
 460                                 case DatabaseBlock::TYPE_RANGE:
 461                                         return $isAnon && $this->options->get( 'CookieSetOnIpBlock' );
 462                                 case DatabaseBlock::TYPE_USER:
 463                                         return !$isAnon &&
 464                                                 $this->options->get( 'CookieSetOnAutoblock' ) &&
 465                                                 $block->isAutoblocking();
 466                                 default:
 467                                         return false;
 468                         }
 469                 }
 470                 return false;
 471         }
 472
 473         /**
 474          * Unset the 'BlockID' cookie.
 475          *
 476          * @since 1.34
 477          * @param WebResponse $response
 478          */
 479         public static function clearBlockCookie( WebResponse $response ) {
 480                 $response->clearCookie( 'BlockID', [ 'httpOnly' => false ] );
 481         }
 482
 483         /**
 484          * Get the stored ID from the 'BlockID' cookie. The cookie's value is usually a combination of
 485          * the ID and a HMAC (see DatabaseBlock::setCookie), but will sometimes only be the ID.
 486          *
 487          * @since 1.34
 488          * @internal Should be private.
 489          *  Left public for backwards compatibility, until DatabaseBlock::getIdFromCookieValue is removed.
 490          * @param string $cookieValue The string in which to find the ID.
 491          * @return int|null The block ID, or null if the HMAC is present and invalid.
 492          */
 493         public function getIdFromCookieValue( $cookieValue ) {
 494                 // The cookie value must start with a number
 495                 if ( !is_numeric( substr( $cookieValue, 0, 1 ) ) ) {
 496                         return null;
 497                 }
 498
 499                 // Extract the ID prefix from the cookie value (may be the whole value, if no bang found).
 500                 $bangPos = strpos( $cookieValue, '!' );
 501                 $id = ( $bangPos === false ) ? $cookieValue : substr( $cookieValue, 0, $bangPos );
 502                 if ( !$this->options->get( 'SecretKey' ) ) {
 503                         // If there's no secret key, just use the ID as given.
 504                         return $id;
 505                 }
 506                 $storedHmac = substr( $cookieValue, $bangPos + 1 );
 507                 $calculatedHmac = MWCryptHash::hmac( $id, $this->options->get( 'SecretKey' ), false );
 508                 if ( $calculatedHmac === $storedHmac ) {
 509                         return $id;
 510                 } else {
 511                         return null;
 512                 }
 513         }
 514
 515         /**
 516          * Get the BlockID cookie's value for this block. This is usually the block ID concatenated
 517          * with an HMAC in order to avoid spoofing (T152951), but if wgSecretKey is not set will just
 518          * be the block ID.
 519          *
 520          * @since 1.34
 521          * @internal Should be private.
 522          *  Left public for backwards compatibility, until DatabaseBlock::getCookieValue is removed.
 523          * @param DatabaseBlock $block
 524          * @return string The block ID, probably concatenated with "!" and the HMAC.
 525          */
 526         public function getCookieValue( DatabaseBlock $block ) {
 527                 $id = $block->getId();
 528                 if ( !$this->options->get( 'SecretKey' ) ) {
 529                         // If there's no secret key, don't append a HMAC.
 530                         return $id;
 531                 }
 532                 $hmac = MWCryptHash::hmac( $id, $this->options->get( 'SecretKey' ), false );
 533                 $cookieValue = $id . '!' . $hmac;
 534                 return $cookieValue;
 535         }
 536
 537 }