1<?php
2/**
3 * The web entry point for serving non-public images to logged-in users.
4 *
5 * To use this, see https://www.mediawiki.org/wiki/Manual:Image_Authorization
6 *
7 * - Set $wgUploadDirectory to a non-public directory (not web accessible)
8 * - Set $wgUploadPath to point to this file
9 *
10 * Optional Parameters
11 *
12 * - Set $wgImgAuthDetails = true if you want the reason the access was denied messages to
13 *       be displayed instead of just the 403 error (doesn't work on IE anyway),
14 *       otherwise it will only appear in error logs
15 *
16 *  For security reasons, you usually don't want your user to know *why* access was denied,
17 *  just that it was. If you want to change this, you can set $wgImgAuthDetails to 'true'
18 *  in localsettings.php and it will give the user the reason why access was denied.
19 *
20 * Your server needs to support REQUEST_URI or PATH_INFO; CGI-based
21 * configurations sometimes don't.
22 *
23 * This program is free software; you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License as published by
25 * the Free Software Foundation; either version 2 of the License, or
26 * (at your option) any later version.
27 *
28 * This program is distributed in the hope that it will be useful,
29 * but WITHOUT ANY WARRANTY; without even the implied warranty of
30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
31 * GNU General Public License for more details.
32 *
33 * You should have received a copy of the GNU General Public License along
34 * with this program; if not, write to the Free Software Foundation, Inc.,
35 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
36 * http://www.gnu.org/copyleft/gpl.html
37 *
38 * @file
39 * @ingroup entrypoint
40 */
41
42define( 'MW_NO_OUTPUT_COMPRESSION', 1 );
43define( 'MW_ENTRY_POINT', 'img_auth' );
44require __DIR__ . '/includes/WebStart.php';
45
46wfImageAuthMain();
47
48$mediawiki = new MediaWiki();
49$mediawiki->doPostOutputShutdown();
50
51function wfImageAuthMain() {
52	global $wgImgAuthUrlPathMap, $wgScriptPath, $wgImgAuthPath;
53
54	$services = \MediaWiki\MediaWikiServices::getInstance();
55	$permissionManager = $services->getPermissionManager();
56
57	$request = RequestContext::getMain()->getRequest();
58	$publicWiki = in_array( 'read', $permissionManager->getGroupPermissions( [ '*' ] ), true );
59
60	// Find the path assuming the request URL is relative to the local public zone URL
61	$baseUrl = $services->getRepoGroup()->getLocalRepo()->getZoneUrl( 'public' );
62	if ( $baseUrl[0] === '/' ) {
63		$basePath = $baseUrl;
64	} else {
65		$basePath = parse_url( $baseUrl, PHP_URL_PATH );
66	}
67	$path = WebRequest::getRequestPathSuffix( $basePath );
68
69	if ( $path === false ) {
70		// Try instead assuming img_auth.php is the base path
71		$basePath = $wgImgAuthPath ?: "$wgScriptPath/img_auth.php";
72		$path = WebRequest::getRequestPathSuffix( $basePath );
73	}
74
75	if ( $path === false ) {
76		wfForbidden( 'img-auth-accessdenied', 'img-auth-notindir' );
77		return;
78	}
79
80	if ( $path === '' || $path[0] !== '/' ) {
81		// Make sure $path has a leading /
82		$path = "/" . $path;
83	}
84
85	$user = RequestContext::getMain()->getUser();
86
87	// Various extensions may have their own backends that need access.
88	// Check if there is a special backend and storage base path for this file.
89	foreach ( $wgImgAuthUrlPathMap as $prefix => $storageDir ) {
90		$prefix = rtrim( $prefix, '/' ) . '/'; // implicit trailing slash
91		if ( strpos( $path, $prefix ) === 0 ) {
92			$be = $services->getFileBackendGroup()->backendFromPath( $storageDir );
93			$filename = $storageDir . substr( $path, strlen( $prefix ) ); // strip prefix
94			// Check basic user authorization
95			$isAllowedUser = $permissionManager->userHasRight( $user, 'read' );
96			if ( !$isAllowedUser ) {
97				wfForbidden( 'img-auth-accessdenied', 'img-auth-noread', $path );
98				return;
99			}
100			if ( $be->fileExists( [ 'src' => $filename ] ) ) {
101				wfDebugLog( 'img_auth', "Streaming `" . $filename . "`." );
102				$be->streamFile( [
103					'src' => $filename,
104					'headers' => [ 'Cache-Control: private', 'Vary: Cookie' ]
105				] );
106			} else {
107				wfForbidden( 'img-auth-accessdenied', 'img-auth-nofile', $path );
108			}
109			return;
110		}
111	}
112
113	// Get the local file repository
114	$repo = $services->getRepoGroup()->getRepo( 'local' );
115	$zone = strstr( ltrim( $path, '/' ), '/', true );
116
117	// Get the full file storage path and extract the source file name.
118	// (e.g. 120px-Foo.png => Foo.png or page2-120px-Foo.png => Foo.png).
119	// This only applies to thumbnails/transcoded, and each of them should
120	// be under a folder that has the source file name.
121	if ( $zone === 'thumb' || $zone === 'transcoded' ) {
122		$name = wfBaseName( dirname( $path ) );
123		$filename = $repo->getZonePath( $zone ) . substr( $path, strlen( "/" . $zone ) );
124		// Check to see if the file exists
125		if ( !$repo->fileExists( $filename ) ) {
126			wfForbidden( 'img-auth-accessdenied', 'img-auth-nofile', $filename );
127			return;
128		}
129	} else {
130		$name = wfBaseName( $path ); // file is a source file
131		$filename = $repo->getZonePath( 'public' ) . $path;
132		// Check to see if the file exists and is not deleted
133		$bits = explode( '!', $name, 2 );
134		if ( substr( $path, 0, 9 ) === '/archive/' && count( $bits ) == 2 ) {
135			$file = $repo->newFromArchiveName( $bits[1], $name );
136		} else {
137			$file = $repo->newFile( $name );
138		}
139		if ( !$file->exists() || $file->isDeleted( File::DELETED_FILE ) ) {
140			wfForbidden( 'img-auth-accessdenied', 'img-auth-nofile', $filename );
141			return;
142		}
143	}
144
145	$headers = []; // extra HTTP headers to send
146
147	$title = Title::makeTitleSafe( NS_FILE, $name );
148
149	if ( !$publicWiki ) {
150		// For private wikis, run extra auth checks and set cache control headers
151		$headers['Cache-Control'] = 'private';
152		$headers['Vary'] = 'Cookie';
153
154		if ( !$title instanceof Title ) { // files have valid titles
155			wfForbidden( 'img-auth-accessdenied', 'img-auth-badtitle', $name );
156			return;
157		}
158
159		// Run hook for extension authorization plugins
160		/** @var array $result */
161		$result = null;
162		if ( !Hooks::runner()->onImgAuthBeforeStream( $title, $path, $name, $result ) ) {
163			wfForbidden( $result[0], $result[1], array_slice( $result, 2 ) );
164			return;
165		}
166
167		// Check user authorization for this title
168		// Checks Whitelist too
169
170		if ( !$permissionManager->userCan( 'read', $user, $title ) ) {
171			wfForbidden( 'img-auth-accessdenied', 'img-auth-noread', $name );
172			return;
173		}
174	}
175
176	if ( isset( $_SERVER['HTTP_RANGE'] ) ) {
177		$headers['Range'] = $_SERVER['HTTP_RANGE'];
178	}
179	if ( isset( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
180		$headers['If-Modified-Since'] = $_SERVER['HTTP_IF_MODIFIED_SINCE'];
181	}
182
183	if ( $request->getCheck( 'download' ) ) {
184		$headers['Content-Disposition'] = 'attachment';
185	}
186
187	// Allow modification of headers before streaming a file
188	Hooks::runner()->onImgAuthModifyHeaders( $title->getTitleValue(), $headers );
189
190	// Stream the requested file
191	list( $headers, $options ) = HTTPFileStreamer::preprocessHeaders( $headers );
192	wfDebugLog( 'img_auth', "Streaming `" . $filename . "`." );
193	$repo->streamFileWithStatus( $filename, $headers, $options );
194}
195
196/**
197 * Issue a standard HTTP 403 Forbidden header ($msg1-a message index, not a message) and an
198 * error message ($msg2, also a message index), (both required) then end the script
199 * subsequent arguments to $msg2 will be passed as parameters only for replacing in $msg2
200 * @param string $msg1
201 * @param string $msg2
202 * @param mixed ...$args To pass as params to wfMessage() with $msg2. Either variadic, or a single
203 *   array argument.
204 */
205function wfForbidden( $msg1, $msg2, ...$args ) {
206	global $wgImgAuthDetails;
207
208	$args = ( isset( $args[0] ) && is_array( $args[0] ) ) ? $args[0] : $args;
209
210	$msgHdr = wfMessage( $msg1 )->text();
211	$detailMsgKey = $wgImgAuthDetails ? $msg2 : 'badaccess-group0';
212	$detailMsg = wfMessage( $detailMsgKey, $args )->text();
213
214	wfDebugLog( 'img_auth',
215		"wfForbidden Hdr: " . wfMessage( $msg1 )->inLanguage( 'en' )->text() . " Msg: " .
216			wfMessage( $msg2, $args )->inLanguage( 'en' )->text()
217	);
218
219	HttpStatus::header( 403 );
220	header( 'Cache-Control: no-cache' );
221	header( 'Content-Type: text/html; charset=utf-8' );
222	$templateParser = new TemplateParser();
223	echo $templateParser->processTemplate( 'ImageAuthForbidden', [
224		'msgHdr' => $msgHdr,
225		'detailMsg' => $detailMsg,
226	] );
227}
228