img_auth.php

   1 <?php
   2 /**
   3  * Image authorisation script
   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 PATH_INFO; CGI-based configurations usually don't.
  21  *
  22  * This program is free software; you can redistribute it and/or modify
  23  * it under the terms of the GNU General Public License as published by
  24  * the Free Software Foundation; either version 2 of the License, or
  25  * (at your option) any later version.
  26  *
  27  * This program is distributed in the hope that it will be useful,
  28  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  29  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  30  * GNU General Public License for more details.
  31  *
  32  * You should have received a copy of the GNU General Public License along
  33  * with this program; if not, write to the Free Software Foundation, Inc.,
  34  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  35  * http://www.gnu.org/copyleft/gpl.html
  36  *
  37  * @file
  38  */
  39
  40 define( 'MW_NO_OUTPUT_COMPRESSION', 1 );
  41 require __DIR__ . '/includes/WebStart.php';
  42
  43 # Set action base paths so that WebRequest::getPathInfo()
  44 # recognizes the "X" as the 'title' in ../img_auth.php/X urls.
  45 $wgArticlePath = false; # Don't let a "/*" article path clober our action path
  46 $wgActionPaths = array( "$wgUploadPath/" );
  47
  48 wfImageAuthMain();
  49 wfLogProfilingData();
  50 // Commit and close up!
  51 $factory = wfGetLBFactory();
  52 $factory->commitMasterChanges();
  53 $factory->shutdown();
  54
  55 function wfImageAuthMain() {
  56         global $wgImgAuthUrlPathMap;
  57
  58         $request = RequestContext::getMain()->getRequest();
  59         $publicWiki = in_array( 'read', User::getGroupPermissions( array( '*' ) ), true );
  60
  61         // Get the requested file path (source file or thumbnail)
  62         $matches = WebRequest::getPathInfo();
  63         if ( !isset( $matches['title'] ) ) {
  64                 wfForbidden( 'img-auth-accessdenied', 'img-auth-nopathinfo' );
  65                 return;
  66         }
  67         $path = $matches['title'];
  68         if ( $path && $path[0] !== '/' ) {
  69                 // Make sure $path has a leading /
  70                 $path = "/" . $path;
  71         }
  72
  73         // Check for bug 28235: QUERY_STRING overriding the correct extension
  74         $whitelist = array();
  75         $extension = FileBackend::extensionFromPath( $path, 'rawcase' );
  76         if ( $extension != '' ) {
  77                 $whitelist[] = $extension;
  78         }
  79         if ( !$request->checkUrlExtension( $whitelist ) ) {
  80                 return;
  81         }
  82
  83         // Various extensions may have their own backends that need access.
  84         // Check if there is a special backend and storage base path for this file.
  85         foreach ( $wgImgAuthUrlPathMap as $prefix => $storageDir ) {
  86                 $prefix = rtrim( $prefix, '/' ) . '/'; // implicit trailing slash
  87                 if ( strpos( $path, $prefix ) === 0 ) {
  88                         $be = FileBackendGroup::singleton()->backendFromPath( $storageDir );
  89                         $filename = $storageDir . substr( $path, strlen( $prefix ) ); // strip prefix
  90                         // Check basic user authorization
  91                         if ( !RequestContext::getMain()->getUser()->isAllowed( 'read' ) ) {
  92                                 wfForbidden( 'img-auth-accessdenied', 'img-auth-noread', $path );
  93                                 return;
  94                         }
  95                         if ( $be->fileExists( array( 'src' => $filename ) ) ) {
  96                                 wfDebugLog( 'img_auth', "Streaming `" . $filename . "`." );
  97                                 $be->streamFile( array( 'src' => $filename ),
  98                                         array( 'Cache-Control: private', 'Vary: Cookie' ) );
  99                         } else {
 100                                 wfForbidden( 'img-auth-accessdenied', 'img-auth-nofile', $path );
 101                         }
 102                         return;
 103                 }
 104         }
 105
 106         // Get the local file repository
 107         $repo = RepoGroup::singleton()->getRepo( 'local' );
 108         $zone = strstr( ltrim( $path, '/' ), '/', true );
 109
 110         // Get the full file storage path and extract the source file name.
 111         // (e.g. 120px-Foo.png => Foo.png or page2-120px-Foo.png => Foo.png).
 112         // This only applies to thumbnails/transcoded, and each of them should
 113         // be under a folder that has the source file name.
 114         if ( $zone === 'thumb' || $zone === 'transcoded' ) {
 115                 $name = wfBaseName( dirname( $path ) );
 116                 $filename = $repo->getZonePath( $zone ) . substr( $path, strlen( "/" . $zone ) );
 117                 // Check to see if the file exists
 118                 if ( !$repo->fileExists( $filename ) ) {
 119                         wfForbidden( 'img-auth-accessdenied', 'img-auth-nofile', $filename );
 120                         return;
 121                 }
 122         } else {
 123                 $name = wfBaseName( $path ); // file is a source file
 124                 $filename = $repo->getZonePath( 'public' ) . $path;
 125                 // Check to see if the file exists and is not deleted
 126                 $bits = explode( '!', $name, 2 );
 127                 if ( substr( $path, 0, 9 ) === '/archive/' && count( $bits ) == 2 ) {
 128                         $file = $repo->newFromArchiveName( $bits[1], $name );
 129                 } else {
 130                         $file = $repo->newFile( $name );
 131                 }
 132                 if ( !$file->exists() || $file->isDeleted( File::DELETED_FILE ) ) {
 133                         wfForbidden( 'img-auth-accessdenied', 'img-auth-nofile', $filename );
 134                         return;
 135                 }
 136         }
 137
 138         $headers = array(); // extra HTTP headers to send
 139
 140         if ( !$publicWiki ) {
 141                 // For private wikis, run extra auth checks and set cache control headers
 142                 $headers[] = 'Cache-Control: private';
 143                 $headers[] = 'Vary: Cookie';
 144
 145                 $title = Title::makeTitleSafe( NS_FILE, $name );
 146                 if ( !$title instanceof Title ) { // files have valid titles
 147                         wfForbidden( 'img-auth-accessdenied', 'img-auth-badtitle', $name );
 148                         return;
 149                 }
 150
 151                 // Run hook for extension authorization plugins
 152                 /** @var $result array */
 153                 $result = null;
 154                 if ( !wfRunHooks( 'ImgAuthBeforeStream', array( &$title, &$path, &$name, &$result ) ) ) {
 155                         wfForbidden( $result[0], $result[1], array_slice( $result, 2 ) );
 156                         return;
 157                 }
 158
 159                 // Check user authorization for this title
 160                 // Checks Whitelist too
 161                 if ( !$title->userCan( 'read' ) ) {
 162                         wfForbidden( 'img-auth-accessdenied', 'img-auth-noread', $name );
 163                         return;
 164                 }
 165         }
 166
 167         if ( $request->getCheck( 'download' ) ) {
 168                 $headers[] = 'Content-Disposition: attachment';
 169         }
 170
 171         // Stream the requested file
 172         wfDebugLog( 'img_auth', "Streaming `" . $filename . "`." );
 173         $repo->streamFile( $filename, $headers );
 174 }
 175
 176 /**
 177  * Issue a standard HTTP 403 Forbidden header ($msg1-a message index, not a message) and an
 178  * error message ($msg2, also a message index), (both required) then end the script
 179  * subsequent arguments to $msg2 will be passed as parameters only for replacing in $msg2
 180  * @param string $msg1
 181  * @param string $msg2
 182  */
 183 function wfForbidden( $msg1, $msg2 ) {
 184         global $wgImgAuthDetails;
 185
 186         $args = func_get_args();
 187         array_shift( $args );
 188         array_shift( $args );
 189         $args = ( isset( $args[0] ) && is_array( $args[0] ) ) ? $args[0] : $args;
 190
 191         $msgHdr = wfMessage( $msg1 )->escaped();
 192         $detailMsgKey = $wgImgAuthDetails ? $msg2 : 'badaccess-group0';
 193         $detailMsg = wfMessage( $detailMsgKey, $args )->escaped();
 194
 195         wfDebugLog( 'img_auth',
 196                 "wfForbidden Hdr: " . wfMessage( $msg1 )->inLanguage( 'en' )->text() . " Msg: " .
 197                         wfMessage( $msg2, $args )->inLanguage( 'en' )->text()
 198         );
 199
 200         header( 'HTTP/1.0 403 Forbidden' );
 201         header( 'Cache-Control: no-cache' );
 202         header( 'Content-Type: text/html; charset=utf-8' );
 203         echo <<<ENDS
 204 <!DOCTYPE html>
 205 <html>
 206 <head>
 207 <meta charset="UTF-8" />
 208 <title>$msgHdr</title>
 209 </head>
 210 <body>
 211 <h1>$msgHdr</h1>
 212 <p>$detailMsg</p>
 213 </body>
 214 </html>
 215 ENDS;
 216 }