img_auth.php
<?php
/**
* The web entry point for serving non-public images to logged-in users.
*
* To use this, see https://www.mediawiki.org/wiki/Manual:Image_authorization
*
* - Set $wgUploadDirectory to a non-public directory (not web accessible)
* - Set $wgUploadPath to point to this file
*
* Optional Parameters
*
* - Set $wgImgAuthDetails = true if you want the reason the access was denied messages to
* be displayed instead of just the 403 error (doesn't work on IE anyway),
* otherwise it will only appear in error logs
*
* For security reasons, you usually don't want your user to know *why* access was denied,
* just that it was. If you want to change this, you can set $wgImgAuthDetails to 'true'
* in localsettings.php and it will give the user the reason why access was denied.
*
* Your server needs to support REQUEST_URI or PATH_INFO; CGI-based
* configurations sometimes don't.
*
* 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
* @ingroup entrypoint
*/
use MediaWiki\Context\RequestContext;
use MediaWiki\HookContainer\HookRunner;
use MediaWiki\Html\TemplateParser;
use MediaWiki\Request\WebRequest;
use MediaWiki\Title\Title;
define( 'MW_NO_OUTPUT_COMPRESSION', 1 );
define( 'MW_ENTRY_POINT', 'img_auth' );
require __DIR__ . '/includes/WebStart.php';
wfImageAuthMain();
$mediawiki = new MediaWiki();
$mediawiki->doPostOutputShutdown();
function wfImageAuthMain() {
global $wgImgAuthUrlPathMap, $wgScriptPath, $wgImgAuthPath;
$services = \MediaWiki\MediaWikiServices::getInstance();
$permissionManager = $services->getPermissionManager();
$request = RequestContext::getMain()->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 = WebRequest::getRequestPathSuffix( $basePath );
if ( $path === false ) {
// Try instead assuming img_auth.php is the base path
$basePath = $wgImgAuthPath ?: "$wgScriptPath/img_auth.php";
$path = WebRequest::getRequestPathSuffix( $basePath );
}
if ( $path === false ) {
wfForbidden( 'img-auth-accessdenied', 'img-auth-notindir' );
return;
}
if ( $path === '' || $path[0] !== '/' ) {
// Make sure $path has a leading /
$path = "/" . $path;
}
$user = RequestContext::getMain()->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.
foreach ( $wgImgAuthUrlPathMap as $prefix => $storageDir ) {
$prefix = rtrim( $prefix, '/' ) . '/'; // implicit trailing slash
if ( strpos( $path, $prefix ) === 0 ) {
$be = $services->getFileBackendGroup()->backendFromPath( $storageDir );
$filename = $storageDir . substr( $path, strlen( $prefix ) ); // strip prefix
// Check basic user authorization
$isAllowedUser = $permissionManager->userHasRight( $user, 'read' );
if ( !$isAllowedUser ) {
wfForbidden( 'img-auth-accessdenied', 'img-auth-noread', $path );
return;
}
if ( $be->fileExists( [ 'src' => $filename ] ) ) {
wfDebugLog( 'img_auth', "Streaming `" . $filename . "`." );
$be->streamFile( [
'src' => $filename,
'headers' => [ 'Cache-Control: private', 'Vary: Cookie' ]
] );
} else {
wfForbidden( 'img-auth-accessdenied', 'img-auth-nofile', $path );
}
return;
}
}
// Get the local file repository
$repo = $services->getRepoGroup()->getRepo( 'local' );
$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 ) ) {
wfForbidden( '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->exists() || $file->isDeleted( File::DELETED_FILE ) ) {
wfForbidden( '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
wfForbidden( 'img-auth-accessdenied', 'img-auth-badtitle', $name );
return;
}
// Run hook for extension authorization plugins
/** @var array $result */
$result = null;
if ( !$hookRunner->onImgAuthBeforeStream( $title, $path, $name, $result ) ) {
wfForbidden( $result[0], $result[1], array_slice( $result, 2 ) );
return;
}
// Check user authorization for this title
// Checks Whitelist too
if ( !$permissionManager->userCan( 'read', $user, $title ) ) {
wfForbidden( 'img-auth-accessdenied', 'img-auth-noread', $name );
return;
}
}
if ( isset( $_SERVER['HTTP_RANGE'] ) ) {
$headers['Range'] = $_SERVER['HTTP_RANGE'];
}
if ( isset( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
$headers['If-Modified-Since'] = $_SERVER['HTTP_IF_MODIFIED_SINCE'];
}
if ( $request->getCheck( 'download' ) ) {
$headers['Content-Disposition'] = 'attachment';
}
// Allow modification of headers before streaming a file
$hookRunner->onImgAuthModifyHeaders( $title->getTitleValue(), $headers );
// Stream the requested file
[ $headers, $options ] = HTTPFileStreamer::preprocessHeaders( $headers );
wfDebugLog( 'img_auth', "Streaming `" . $filename . "`." );
$repo->streamFileWithStatus( $filename, $headers, $options );
}
/**
* Issue a standard HTTP 403 Forbidden header ($msg1-a message index, not a message) and an
* error message ($msg2, also a message index), (both required) then end the script
* subsequent arguments to $msg2 will be passed as parameters only for replacing in $msg2
* @param string $msg1
* @param string $msg2
* @param mixed ...$args To pass as params to wfMessage() with $msg2. Either variadic, or a single
* array argument.
*/
function wfForbidden( $msg1, $msg2, ...$args ) {
global $wgImgAuthDetails;
$args = ( isset( $args[0] ) && is_array( $args[0] ) ) ? $args[0] : $args;
$msgHdr = wfMessage( $msg1 )->text();
$detailMsgKey = $wgImgAuthDetails ? $msg2 : 'badaccess-group0';
$detailMsg = wfMessage( $detailMsgKey, $args )->text();
wfDebugLog( 'img_auth',
"wfForbidden Hdr: " . wfMessage( $msg1 )->inLanguage( 'en' )->text() . " Msg: " .
wfMessage( $msg2, $args )->inLanguage( 'en' )->text()
);
HttpStatus::header( 403 );
header( 'Cache-Control: no-cache' );
header( 'Content-Type: text/html; charset=utf-8' );
$templateParser = new TemplateParser();
echo $templateParser->processTemplate( 'ImageAuthForbidden', [
'msgHdr' => $msgHdr,
'detailMsg' => $detailMsg,
] );
}