CentralIdLookup: Add @since to factoryNonLocal()

[mediawiki.git] / includes / block / BlockManager.php

<?php
/**
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

namespace MediaWiki\Block;

use DateTime;
use DateTimeZone;
use LogicException;
use MediaWiki\Config\ServiceOptions;
use MediaWiki\HookContainer\HookContainer;
use MediaWiki\HookContainer\HookRunner;
use MediaWiki\Permissions\PermissionManager;
use MediaWiki\User\UserIdentity;
use Message;
use MWCryptHash;
use Psr\Log\LoggerInterface;
use User;
use WebRequest;
use WebResponse;
use Wikimedia\IPSet;
use Wikimedia\IPUtils;

/**
 * A service class for checking blocks.
 * To obtain an instance, use MediaWikiServices::getInstance()->getBlockManager().
 *
 * @since 1.34 Refactored from User and Block.
 */
class BlockManager {
        /** @var PermissionManager */
        private $permissionManager;

        /** @var ServiceOptions */
        private $options;

        /**
         * @internal For use by ServiceWiring
         */
        public const CONSTRUCTOR_OPTIONS = [
                'ApplyIpBlocksToXff',
                'CookieSetOnAutoblock',
                'CookieSetOnIpBlock',
                'DnsBlacklistUrls',
                'EnableDnsBlacklist',
                'ProxyList',
                'ProxyWhitelist',
                'SecretKey',
                'SoftBlockRanges',
        ];

        /** @var LoggerInterface */
        private $logger;

        /** @var HookRunner */
        private $hookRunner;

        /**
         * @param ServiceOptions $options
         * @param PermissionManager $permissionManager
         * @param LoggerInterface $logger
         * @param HookContainer $hookContainer
         */
        public function __construct(
                ServiceOptions $options,
                PermissionManager $permissionManager,
                LoggerInterface $logger,
                HookContainer $hookContainer
        ) {
                $options->assertRequiredOptions( self::CONSTRUCTOR_OPTIONS );
                $this->options = $options;
                $this->permissionManager = $permissionManager;
                $this->logger = $logger;
                $this->hookRunner = new HookRunner( $hookContainer );
        }

        /**
         * Get the blocks that apply to a user. If there is only one, return that, otherwise
         * return a composite block that combines the strictest features of the applicable
         * blocks.
         *
         * Different blocks may be sought, depending on the user and their permissions. The
         * user may be:
         * (1) The global user (and can be affected by IP blocks). The global request object
         * is needed for checking the IP address, the XFF header and the cookies.
         * (2) The global user (and exempt from IP blocks). The global request object is
         * available.
         * (3) Another user (not the global user). No request object is available or needed;
         * just look for a block against the user account.
         *
         * Cases #1 and #2 check whether the global user is blocked in practice; the block
         * may due to their user account being blocked or to an IP address block or cookie
         * block (or multiple of these). Case #3 simply checks whether a user's account is
         * blocked, and does not determine whether the person using that account is affected
         * in practice by any IP address or cookie blocks.
         *
         * @internal This should only be called by User::getBlockedStatus
         * @param User $user
         * @param WebRequest|null $request The global request object if the user is the
         *  global user (cases #1 and #2), otherwise null (case #3). The IP address and
         *  information from the request header are needed to find some types of blocks.
         * @param bool $fromReplica Whether to check the replica DB first.
         *  To improve performance, non-critical checks are done against replica DBs.
         *  Check when actually saving should be done against master.
         * @return AbstractBlock|null The most relevant block, or null if there is no block.
         */
        public function getUserBlock( User $user, $request, $fromReplica ) {
                $fromMaster = !$fromReplica;
                $ip = null;

                // If this is the global user, they may be affected by IP blocks (case #1),
                // or they may be exempt (case #2). If affected, look for additional blocks
                // against the IP address and referenced in a cookie.
                $checkIpBlocks = $request &&
                        !$this->permissionManager->userHasRight( $user, 'ipblock-exempt' );

                if ( $request && $checkIpBlocks ) {

                        // Case #1: checking the global user, including IP blocks
                        $ip = $request->getIP();
                        // TODO: remove dependency on DatabaseBlock (T221075)
                        $blocks = DatabaseBlock::newListFromTarget( $user, $ip, $fromMaster );
                        $this->getAdditionalIpBlocks( $blocks, $request, !$user->isRegistered(), $fromMaster );
                        $this->getCookieBlock( $blocks, $user, $request );

                } else {

                        // Case #2: checking the global user, but they are exempt from IP blocks
                        // and cookie blocks, so we only check for a user account block.
                        // Case #3: checking whether another user's account is blocked.
                        // TODO: remove dependency on DatabaseBlock (T221075)
                        $blocks = DatabaseBlock::newListFromTarget( $user, null, $fromMaster );

                }

                // Filter out any duplicated blocks, e.g. from the cookie
                $blocks = $this->getUniqueBlocks( $blocks );

                $block = null;
                if ( count( $blocks ) > 0 ) {
                        if ( count( $blocks ) === 1 ) {
                                $block = $blocks[ 0 ];
                        } else {
                                $block = new CompositeBlock( [
                                        'address' => $ip,
                                        'reason' => new Message( 'blockedtext-composite-reason' ),
                                        'originalBlocks' => $blocks,
                                ] );
                        }
                }

                $this->hookRunner->onGetUserBlock( clone $user, $ip, $block );

                return $block;
        }

        /**
         * Get the cookie block, if there is one.
         *
         * @param AbstractBlock[] &$blocks
         * @param UserIdentity $user
         * @param WebRequest $request
         * @return void
         */
        private function getCookieBlock( &$blocks, UserIdentity $user, WebRequest $request ) {
                $cookieBlock = $this->getBlockFromCookieValue( $user, $request );
                if ( $cookieBlock instanceof DatabaseBlock ) {
                        $blocks[] = $cookieBlock;
                }
        }

        /**
         * Check for any additional blocks against the IP address or any IPs in the XFF header.
         *
         * @param AbstractBlock[] &$blocks Blocks found so far
         * @param WebRequest $request
         * @param bool $isAnon The user is logged out
         * @param bool $fromMaster
         * @return void
         */
        private function getAdditionalIpBlocks( &$blocks, WebRequest $request, $isAnon, $fromMaster ) {
                $ip = $request->getIP();

                // Proxy blocking
                if ( !in_array( $ip, $this->options->get( 'ProxyWhitelist' ) ) ) {
                        // Local list
                        if ( $this->isLocallyBlockedProxy( $ip ) ) {
                                $blocks[] = new SystemBlock( [
                                        'reason' => new Message( 'proxyblockreason' ),
                                        'address' => $ip,
                                        'systemBlock' => 'proxy',
                                ] );
                        } elseif ( $isAnon && $this->isDnsBlacklisted( $ip ) ) {
                                $blocks[] = new SystemBlock( [
                                        'reason' => new Message( 'sorbsreason' ),
                                        'address' => $ip,
                                        'systemBlock' => 'dnsbl',
                                ] );
                        }
                }

                // Soft blocking
                if ( $isAnon && IPUtils::isInRanges( $ip, $this->options->get( 'SoftBlockRanges' ) ) ) {
                        $blocks[] = new SystemBlock( [
                                'address' => $ip,
                                'reason' => new Message( 'softblockrangesreason', [ $ip ] ),
                                'anonOnly' => true,
                                'systemBlock' => 'wgSoftBlockRanges',
                        ] );
                }

                // (T25343) Apply IP blocks to the contents of XFF headers, if enabled
                if ( $this->options->get( 'ApplyIpBlocksToXff' )
                        && !in_array( $ip, $this->options->get( 'ProxyWhitelist' ) )
                ) {
                        $xff = $request->getHeader( 'X-Forwarded-For' );
                        $xff = array_map( 'trim', explode( ',', $xff ) );
                        $xff = array_diff( $xff, [ $ip ] );
                        // TODO: remove dependency on DatabaseBlock (T221075)
                        $xffblocks = DatabaseBlock::getBlocksForIPList( $xff, $isAnon, $fromMaster );
                        $blocks = array_merge( $blocks, $xffblocks );
                }
        }

        /**
         * Given a list of blocks, return a list of unique blocks.
         *
         * This usually means that each block has a unique ID. For a block with ID null,
         * if it's an autoblock, it will be filtered out if the parent block is present;
         * if not, it is assumed to be a unique system block, and kept.
         *
         * @param AbstractBlock[] $blocks
         * @return AbstractBlock[]
         */
        private function getUniqueBlocks( array $blocks ) {
                $systemBlocks = [];
                $databaseBlocks = [];

                foreach ( $blocks as $block ) {
                        if ( $block instanceof SystemBlock ) {
                                $systemBlocks[] = $block;
                        } elseif ( $block->getType() === DatabaseBlock::TYPE_AUTO ) {
                                /** @var DatabaseBlock $block */
                                '@phan-var DatabaseBlock $block';
                                if ( !isset( $databaseBlocks[$block->getParentBlockId()] ) ) {
                                        $databaseBlocks[$block->getParentBlockId()] = $block;
                                }
                        } else {
                                $databaseBlocks[$block->getId()] = $block;
                        }
                }

                return array_values( array_merge( $systemBlocks, $databaseBlocks ) );
        }

        /**
         * Try to load a block from an ID given in a cookie value.
         *
         * If the block is invalid, doesn't exist, or the cookie value is malformed, no
         * block will be loaded. In these cases the cookie will either (1) be replaced
         * with a valid cookie or (2) removed, next time trackBlockWithCookie is called.
         *
         * @param UserIdentity $user
         * @param WebRequest $request
         * @return DatabaseBlock|bool The block object, or false if none could be loaded.
         */
        private function getBlockFromCookieValue(
                UserIdentity $user,
                WebRequest $request
        ) {
                $cookieValue = $request->getCookie( 'BlockID' );
                if ( $cookieValue === null ) {
                        return false;
                }

                $blockCookieId = $this->getIdFromCookieValue( $cookieValue );
                if ( $blockCookieId !== null ) {
                        // TODO: remove dependency on DatabaseBlock (T221075)
                        $block = DatabaseBlock::newFromID( $blockCookieId );
                        if (
                                $block instanceof DatabaseBlock &&
                                $this->shouldApplyCookieBlock( $block, !$user->isRegistered() )
                        ) {
                                return $block;
                        }
                }

                return false;
        }

        /**
         * Check if the block loaded from the cookie should be applied.
         *
         * @param DatabaseBlock $block
         * @param bool $isAnon The user is logged out
         * @return bool The block sould be applied
         */
        private function shouldApplyCookieBlock( DatabaseBlock $block, $isAnon ) {
                if ( !$block->isExpired() ) {
                        switch ( $block->getType() ) {
                                case DatabaseBlock::TYPE_IP:
                                case DatabaseBlock::TYPE_RANGE:
                                        // If block is type IP or IP range, load only
                                        // if user is not logged in (T152462)
                                        return $isAnon &&
                                                $this->options->get( 'CookieSetOnIpBlock' );
                                case DatabaseBlock::TYPE_USER:
                                        return $block->isAutoblocking() &&
                                                $this->options->get( 'CookieSetOnAutoblock' );
                                default:
                                        return false;
                        }
                }
                return false;
        }

        /**
         * Check if an IP address is in the local proxy list
         *
         * @param string $ip
         * @return bool
         */
        private function isLocallyBlockedProxy( $ip ) {
                $proxyList = $this->options->get( 'ProxyList' );
                if ( !$proxyList ) {
                        return false;
                }

                if ( !is_array( $proxyList ) ) {
                        // Load values from the specified file
                        $proxyList = array_map( 'trim', file( $proxyList ) );
                }

                $proxyListIPSet = new IPSet( $proxyList );
                return $proxyListIPSet->match( $ip );
        }

        /**
         * Whether the given IP is in a DNS blacklist.
         *
         * @param string $ip IP to check
         * @param bool $checkWhitelist Whether to check the whitelist first
         * @return bool True if blacklisted.
         */
        public function isDnsBlacklisted( $ip, $checkWhitelist = false ) {
                if ( !$this->options->get( 'EnableDnsBlacklist' ) ||
                        ( $checkWhitelist && in_array( $ip, $this->options->get( 'ProxyWhitelist' ) ) )
                ) {
                        return false;
                }

                return $this->inDnsBlacklist( $ip, $this->options->get( 'DnsBlacklistUrls' ) );
        }

        /**
         * Whether the given IP is in a given DNS blacklist.
         *
         * @param string $ip IP to check
         * @param array $bases Array of Strings: URL of the DNS blacklist
         * @return bool True if blacklisted.
         */
        private function inDnsBlacklist( $ip, array $bases ) {
                $found = false;
                // @todo FIXME: IPv6 ???  (https://bugs.php.net/bug.php?id=33170)
                if ( IPUtils::isIPv4( $ip ) ) {
                        // Reverse IP, T23255
                        $ipReversed = implode( '.', array_reverse( explode( '.', $ip ) ) );

                        foreach ( $bases as $base ) {
                                // Make hostname
                                // If we have an access key, use that too (ProjectHoneypot, etc.)
                                $basename = $base;
                                if ( is_array( $base ) ) {
                                        if ( count( $base ) >= 2 ) {
                                                // Access key is 1, base URL is 0
                                                $hostname = "{$base[1]}.$ipReversed.{$base[0]}";
                                        } else {
                                                $hostname = "$ipReversed.{$base[0]}";
                                        }
                                        $basename = $base[0];
                                } else {
                                        $hostname = "$ipReversed.$base";
                                }

                                // Send query
                                $ipList = $this->checkHost( $hostname );

                                if ( $ipList ) {
                                        $this->logger->info(
                                                "Hostname $hostname is {$ipList[0]}, it's a proxy says $basename!"
                                        );
                                        $found = true;
                                        break;
                                }

                                $this->logger->debug( "Requested $hostname, not found in $basename." );
                        }
                }

                return $found;
        }

        /**
         * Wrapper for mocking in tests.
         *
         * @param string $hostname DNSBL query
         * @return string[]|bool IPv4 array, or false if the IP is not blacklisted
         */
        protected function checkHost( $hostname ) {
                return gethostbynamel( $hostname );
        }

        /**
         * Set the 'BlockID' cookie depending on block type and user authentication status.
         *
         * If a block cookie is already set, this will check the block that the cookie references
         * and do the following:
         *  - If the block is a valid block that should be applied, do nothing and return early.
         *    This ensures that the cookie's expiry time is based on the time of the first page
         *    load or attempt. (See discussion on T233595.)
         *  - If the block is invalid (e.g. has expired), clear the cookie and continue to check
         *    whether there is another block that should be tracked.
         *  - If the block is a valid block, but should not be tracked by a cookie, clear the
         *    cookie and continue to check whether there is another block that should be tracked.
         *
         * @since 1.34
         * @param User $user
         * @param WebResponse $response The response on which to set the cookie.
         * @throws LogicException If called before the User object was loaded.
         * @throws LogicException If not called pre-send.
         */
        public function trackBlockWithCookie( User $user, WebResponse $response ) {
                $request = $user->getRequest();

                if ( $request->getCookie( 'BlockID' ) !== null ) {
                        $cookieBlock = $this->getBlockFromCookieValue( $user, $request );
                        if ( $cookieBlock && $this->shouldApplyCookieBlock( $cookieBlock, $user->isAnon() ) ) {
                                return;
                        }
                        // The block pointed to by the cookie is invalid or should not be tracked.
                        $this->clearBlockCookie( $response );
                }

                if ( !$user->isSafeToLoad() ) {
                        // Prevent a circular dependency by not allowing this method to be called
                        // before or while the user is being loaded.
                        // E.g. User > BlockManager > Block > Message > getLanguage > User.
                        // See also T180050 and T226777.
                        throw new LogicException( __METHOD__ . ' requires a loaded User object' );
                }
                if ( $response->headersSent() ) {
                        throw new LogicException( __METHOD__ . ' must be called pre-send' );
                }

                $block = $user->getBlock();
                $isAnon = $user->isAnon();

                if ( $block ) {
                        if ( $block instanceof CompositeBlock ) {
                                // TODO: Improve on simply tracking the first trackable block (T225654)
                                foreach ( $block->getOriginalBlocks() as $originalBlock ) {
                                        if ( $this->shouldTrackBlockWithCookie( $originalBlock, $isAnon ) ) {
                                                '@phan-var DatabaseBlock $originalBlock';
                                                $this->setBlockCookie( $originalBlock, $response );
                                                return;
                                        }
                                }
                        } else {
                                if ( $this->shouldTrackBlockWithCookie( $block, $isAnon ) ) {
                                        '@phan-var DatabaseBlock $block';
                                        $this->setBlockCookie( $block, $response );
                                }
                        }
                }
        }

        /**
         * Set the 'BlockID' cookie to this block's ID and expiry time. The cookie's expiry will be
         * the same as the block's, to a maximum of 24 hours.
         *
         * @since 1.34
         * @internal Should be private.
         *  Left public for backwards compatibility, until DatabaseBlock::setCookie is removed.
         * @param DatabaseBlock $block
         * @param WebResponse $response The response on which to set the cookie.
         */
        public function setBlockCookie( DatabaseBlock $block, WebResponse $response ) {
                // Calculate the default expiry time.
                $maxExpiryTime = wfTimestamp( TS_MW, (int)wfTimestamp() + ( 24 * 60 * 60 ) );

                // Use the block's expiry time only if it's less than the default.
                $expiryTime = $block->getExpiry();
                if ( $expiryTime === 'infinity' || $expiryTime > $maxExpiryTime ) {
                        $expiryTime = $maxExpiryTime;
                }

                // Set the cookie. Reformat the MediaWiki datetime as a Unix timestamp for the cookie.
                $expiryValue = DateTime::createFromFormat(
                        'YmdHis',
                        $expiryTime,
                        new DateTimeZone( 'UTC' )
                )->format( 'U' );
                $cookieOptions = [ 'httpOnly' => false ];
                $cookieValue = $this->getCookieValue( $block );
                $response->setCookie( 'BlockID', $cookieValue, $expiryValue, $cookieOptions );
        }

        /**
         * Check if the block should be tracked with a cookie.
         *
         * @param AbstractBlock $block
         * @param bool $isAnon The user is logged out
         * @return bool The block sould be tracked with a cookie
         */
        private function shouldTrackBlockWithCookie( AbstractBlock $block, $isAnon ) {
                if ( $block instanceof DatabaseBlock ) {
                        switch ( $block->getType() ) {
                                case DatabaseBlock::TYPE_IP:
                                case DatabaseBlock::TYPE_RANGE:
                                        return $isAnon && $this->options->get( 'CookieSetOnIpBlock' );
                                case DatabaseBlock::TYPE_USER:
                                        return !$isAnon &&
                                                $this->options->get( 'CookieSetOnAutoblock' ) &&
                                                $block->isAutoblocking();
                                default:
                                        return false;
                        }
                }
                return false;
        }

        /**
         * Unset the 'BlockID' cookie.
         *
         * @since 1.34
         * @param WebResponse $response
         */
        public static function clearBlockCookie( WebResponse $response ) {
                $response->clearCookie( 'BlockID', [ 'httpOnly' => false ] );
        }

        /**
         * Get the stored ID from the 'BlockID' cookie. The cookie's value is usually a combination of
         * the ID and a HMAC (see DatabaseBlock::setCookie), but will sometimes only be the ID.
         *
         * @since 1.34
         * @internal Should be private.
         *  Left public for backwards compatibility, until DatabaseBlock::getIdFromCookieValue is removed.
         * @param string $cookieValue The string in which to find the ID.
         * @return int|null The block ID, or null if the HMAC is present and invalid.
         */
        public function getIdFromCookieValue( $cookieValue ) {
                // The cookie value must start with a number
                if ( !is_numeric( substr( $cookieValue, 0, 1 ) ) ) {
                        return null;
                }

                // Extract the ID prefix from the cookie value (may be the whole value, if no bang found).
                $bangPos = strpos( $cookieValue, '!' );
                $id = ( $bangPos === false ) ? $cookieValue : substr( $cookieValue, 0, $bangPos );
                if ( !$this->options->get( 'SecretKey' ) ) {
                        // If there's no secret key, just use the ID as given.
                        return (int)$id;
                }
                $storedHmac = substr( $cookieValue, $bangPos + 1 );
                $calculatedHmac = MWCryptHash::hmac( $id, $this->options->get( 'SecretKey' ), false );
                if ( $calculatedHmac === $storedHmac ) {
                        return (int)$id;
                } else {
                        return null;
                }
        }

        /**
         * Get the BlockID cookie's value for this block. This is usually the block ID concatenated
         * with an HMAC in order to avoid spoofing (T152951), but if wgSecretKey is not set will just
         * be the block ID.
         *
         * @since 1.34
         * @internal Should be private.
         *  Left public for backwards compatibility, until DatabaseBlock::getCookieValue is removed.
         * @param DatabaseBlock $block
         * @return string The block ID, probably concatenated with "!" and the HMAC.
         */
        public function getCookieValue( DatabaseBlock $block ) {
                $id = $block->getId();
                if ( !$this->options->get( 'SecretKey' ) ) {
                        // If there's no secret key, don't append a HMAC.
                        return $id;
                }
                $hmac = MWCryptHash::hmac( $id, $this->options->get( 'SecretKey' ), false );
                $cookieValue = $id . '!' . $hmac;
                return $cookieValue;
        }

}