AuthenticatedFileEntryPoint.php

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<?php
namespace MediaWiki\FileRepo;
 
use MediaWiki\FileRepo\File\File;
use MediaWiki\HookContainer\HookRunner;
use MediaWiki\Html\TemplateParser;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiEntryPoint;
use MediaWiki\Request\ContentSecurityPolicy;
use MediaWiki\Title\Title;
use Wikimedia\FileBackend\HTTPFileStreamer;
use Wikimedia\Message\MessageParam;
use Wikimedia\Message\MessageSpecifier;
 
class AuthenticatedFileEntryPoint extends MediaWikiEntryPoint {
 
    public function execute() {
        $services = $this->getServiceContainer();
        $permissionManager = $services->getPermissionManager();
 
        $request = $this->getRequest();
        $publicWiki = $services->getGroupPermissionsLookup()->groupHasPermission( '*', 'read' );
 
        // Find the path assuming the request URL is relative to the local public zone URL
        $baseUrl = $services->getRepoGroup()->getLocalRepo()->getZoneUrl( 'public' );
        if ( $baseUrl[0] === '/' ) {
            $basePath = $baseUrl;
        } else {
            $basePath = parse_url( $baseUrl, PHP_URL_PATH );
        }
        $path = $this->getRequestPathSuffix( "$basePath" );
 
        if ( $path === false ) {
            // Try instead assuming img_auth.php is the base path
            $basePath = $this->getConfig( MainConfigNames::ImgAuthPath )
                ?: $this->getConfig( MainConfigNames::ScriptPath ) . '/img_auth.php';
            $path = $this->getRequestPathSuffix( $basePath );
        }
 
        if ( $path === false ) {
            $this->forbidden( 'img-auth-accessdenied', 'img-auth-notindir' );
            return;
        }
 
        if ( $path === '' || $path[0] !== '/' ) {
            // Make sure $path has a leading /
            $path = "/" . $path;
        }
 
        $user = $this->getContext()->getUser();
 
        // Various extensions may have their own backends that need access.
        // Check if there is a special backend and storage base path for this file.
        $pathMap = $this->getConfig( MainConfigNames::ImgAuthUrlPathMap );
        foreach ( $pathMap as $prefix => $storageDir ) {
            $prefix = rtrim( $prefix, '/' ) . '/'; // implicit trailing slash
            if ( str_starts_with( $path, $prefix ) ) {
                $be = $services->getFileBackendGroup()->backendFromPath( $storageDir );
                $filename = $storageDir . substr( $path, strlen( $prefix ) ); // strip prefix
                // Check basic user authorization
                $isAllowedUser = $permissionManager->userHasRight( $user, 'read' );
                if ( !$isAllowedUser ) {
                    $this->forbidden( 'img-auth-accessdenied', 'img-auth-noread', $path );
                    return;
                }
                if ( $be && $be->fileExists( [ 'src' => $filename ] ) ) {
                    wfDebugLog( 'img_auth', "Streaming `" . $filename . "`." );
                    $be->streamFile( [
                        'src' => $filename,
                        'headers' => [ 'Cache-Control: private', 'Vary: Cookie' ]
                    ] );
                } else {
                    $this->forbidden( 'img-auth-accessdenied', 'img-auth-nofile', $path );
                }
 
                return;
            }
        }
 
        // Get the local file repository
        $repo = $services->getRepoGroup()->getLocalRepo();
        $zone = strstr( ltrim( $path, '/' ), '/', true );
 
        // Get the full file storage path and extract the source file name.
        // (e.g. 120px-Foo.png => Foo.png or page2-120px-Foo.png => Foo.png).
        // This only applies to thumbnails/transcoded, and each of them should
        // be under a folder that has the source file name.
        if ( $zone === 'thumb' || $zone === 'transcoded' ) {
            $name = wfBaseName( dirname( $path ) );
            $filename = $repo->getZonePath( $zone ) . substr( $path, strlen( "/" . $zone ) );
            // Check to see if the file exists
            if ( !$repo->fileExists( $filename ) ) {
                $this->forbidden( 'img-auth-accessdenied', 'img-auth-nofile', $filename );
                return;
            }
        } else {
            $name = wfBaseName( $path ); // file is a source file
            $filename = $repo->getZonePath( 'public' ) . $path;
            // Check to see if the file exists and is not deleted
            $bits = explode( '!', $name, 2 );
            if ( str_starts_with( $path, '/archive/' ) && count( $bits ) == 2 ) {
                $file = $repo->newFromArchiveName( $bits[1], $name );
            } else {
                $file = $repo->newFile( $name );
            }
            if ( !$file || !$file->exists() || $file->isDeleted( File::DELETED_FILE ) ) {
                $this->forbidden( 'img-auth-accessdenied', 'img-auth-nofile', $filename );
                return;
            }
        }
 
        $headers = []; // extra HTTP headers to send
 
        $title = Title::makeTitleSafe( NS_FILE, $name );
 
        $hookRunner = new HookRunner( $services->getHookContainer() );
        if ( !$publicWiki ) {
            // For private wikis, run extra auth checks and set cache control headers
            $headers['Cache-Control'] = 'private';
            $headers['Vary'] = 'Cookie';
 
            if ( !$title instanceof Title ) { // files have valid titles
                $this->forbidden( 'img-auth-accessdenied', 'img-auth-badtitle', $name );
                return;
            }
 
            // Run hook for extension authorization plugins
            $authResult = [];
            if ( !$hookRunner->onImgAuthBeforeStream( $title, $path, $name, $authResult ) ) {
                $this->forbidden( $authResult[0], $authResult[1], array_slice( $authResult, 2 ) );
                return;
            }
 
            if ( !$permissionManager->userCan( 'read', $user, $title ) ) {
                $this->forbidden( 'img-auth-accessdenied', 'img-auth-noread', $name );
                return;
            }
        }
 
        $range = $this->environment->getServerInfo( 'HTTP_RANGE' );
        $ims = $this->environment->getServerInfo( 'HTTP_IF_MODIFIED_SINCE' );
 
        if ( $range !== null ) {
            $headers['Range'] = $range;
        }
        if ( $ims !== null ) {
            $headers['If-Modified-Since'] = $ims;
        }
 
        if ( $request->getCheck( 'download' ) ) {
            $headers['Content-Disposition'] = 'attachment';
        }
 
        $cspHeader = ContentSecurityPolicy::getMediaHeader( $filename );
        if ( $cspHeader ) {
            $headers['Content-Security-Policy'] = $cspHeader;
        }
 
        // Allow modification of headers before streaming a file
        $hookRunner->onImgAuthModifyHeaders( $title->getTitleValue(), $headers );
 
        // Stream the requested file
        $this->prepareForOutput();
 
        [ $headers, $options ] = HTTPFileStreamer::preprocessHeaders( $headers );
        wfDebugLog( 'img_auth', "Streaming `" . $filename . "`." );
        $repo->streamFileWithStatus( $filename, $headers, $options );
 
        $this->enterPostSendMode();
    }
 
    private function forbidden( $msg1, $msg2, ...$args ) {
        $args = ( isset( $args[0] ) && is_array( $args[0] ) ) ? $args[0] : $args;
        $context = $this->getContext();
 
        $msgHdr = $context->msg( $msg1 )->text();
        $detailMsg = $this->getConfig( MainConfigNames::ImgAuthDetails )
            ? $context->msg( $msg2, $args )->text()
            : $context->msg( 'badaccess-group0' )->text();
 
        wfDebugLog(
            'img_auth',
            "wfForbidden Hdr: " . $context->msg( $msg1 )->inLanguage( 'en' )->text()
                . " Msg: " . $context->msg( $msg2, $args )->inLanguage( 'en' )->text()
        );
 
        $this->status( 403 );
        $this->header( 'Cache-Control: no-cache' );
        $this->header( 'Content-Type: text/html; charset=utf-8' );
        $language = $context->getLanguage();
        $lang = $language->getHtmlCode();
        $this->header( "Content-Language: $lang" );
        $templateParser = new TemplateParser();
        $this->print(
            $templateParser->processTemplate( 'ImageAuthForbidden', [
                'dir' => $language->getDir(),
                'lang' => $lang,
                'msgHdr' => $msgHdr,
                'detailMsg' => $detailMsg,
            ] )
        );
    }
}