img_auth.php

   1 <?php
   2
   3 /**
   4  * Image authorisation script
   5  *
   6  * To use this, see http://www.mediawiki.org/wiki/Manual:Image_Authorization
   7  *
   8  * - Set $wgUploadDirectory to a non-public directory (not web accessible)
   9  * - Set $wgUploadPath to point to this file
  10  *
  11  * Optional Parameters
  12  *
  13  * - Set $wgImgAuthDetails = true if you want the reason the access was denied messages to
  14  *       be displayed instead of just the 403 error (doesn't work on IE anyway),
  15  *       otherwise it will only appear in error logs
  16  * - Set $wgImgAuthPublicTest false if you don't want to just check and see if all are public
  17  *       must be set to false if using specific restrictions such as LockDown or NSFileRepo
  18  *
  19  *  For security reasons, you usually don't want your user to know *why* access was denied,
  20  *  just that it was. If you want to change this, you can set $wgImgAuthDetails to 'true'
  21  *  in localsettings.php and it will give the user the reason why access was denied.
  22  *
  23  * Your server needs to support PATH_INFO; CGI-based configurations usually don't.
  24  *
  25  * @file
  26  *
  27  **/
  28
  29 define( 'MW_NO_OUTPUT_COMPRESSION', 1 );
  30 if ( isset( $_SERVER['MW_COMPILED'] ) ) {
  31         require ( 'core/includes/WebStart.php' );
  32 } else {
  33         require ( dirname( __FILE__ ) . '/includes/WebStart.php' );
  34 }
  35 wfProfileIn( 'img_auth.php' );
  36
  37 # Set action base paths so that WebRequest::getPathInfo()
  38 # recognizes the "X" as the 'title' in ../image_auth/X urls.
  39 $wgArticlePath = false; # Don't let a "/*" article path clober our action path
  40 $wgActionPaths = array( "$wgUploadPath/" );
  41
  42 wfImageAuthMain();
  43 wfLogProfilingData();
  44
  45 function wfImageAuthMain() {
  46         global $wgImgAuthPublicTest, $wgRequest;
  47
  48         // See if this is a public Wiki (no protections).
  49         if ( $wgImgAuthPublicTest
  50                 && in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) )
  51         {
  52                 // This is a public wiki, so disable this script (for private wikis only)
  53                 wfForbidden( 'img-auth-accessdenied', 'img-auth-public' );
  54                 return;
  55         }
  56
  57         // Get the requested file path (source file or thumbnail)
  58         $matches = WebRequest::getPathInfo();
  59         if ( !isset( $matches['title'] ) ) {
  60                 wfForbidden( 'img-auth-accessdenied', 'img-auth-nopathinfo' );
  61                 return;
  62         }
  63         $path = $matches['title'];
  64         if ( $path && $path[0] !== '/' ) {
  65                 // Make sure $path has a leading /
  66                 $path = "/" . $path;
  67         }
  68
  69         // Check for bug 28235: QUERY_STRING overriding the correct extension
  70         $whitelist = array();
  71         $dotPos = strrpos( $path, '.' );
  72         if ( $dotPos !== false ) {
  73                 $whitelist[] = substr( $path, $dotPos + 1 );
  74         }
  75         if ( !$wgRequest->checkUrlExtension( $whitelist ) ) {
  76                 return;
  77         }
  78
  79         // Get the local file repository
  80         $repo = RepoGroup::singleton()->getRepo( 'local' );
  81
  82         // Get the full file storage path and extract the source file name.
  83         // (e.g. 120px-Foo.png => Foo.png or page2-120px-Foo.png => Foo.png).
  84         // This only applies to thumbnails, and all thumbnails should
  85         // be under a folder that has the source file name.
  86         if ( strpos( $path, '/thumb/' ) === 0 ) {
  87                 $name = wfBaseName( dirname( $path ) ); // file is a thumbnail
  88                 $filename = $repo->getZonePath( 'thumb' ) . substr( $path, 6 ); // strip "/thumb"
  89         } else {
  90                 $name = wfBaseName( $path ); // file is a source file
  91                 $filename = $repo->getZonePath( 'public' ) . $path;
  92         }
  93
  94         // Check to see if the file exists
  95         if ( !$repo->fileExists( $filename ) ) {
  96                 wfForbidden( 'img-auth-accessdenied','img-auth-nofile', $filename );
  97                 return;
  98         }
  99
 100         $title = Title::makeTitleSafe( NS_FILE, $name );
 101         if ( !$title instanceof Title ) { // files have valid titles
 102                 wfForbidden( 'img-auth-accessdenied', 'img-auth-badtitle', $name );
 103                 return;
 104         }
 105
 106         // Run hook for extension authorization plugins
 107         if ( !wfRunHooks( 'ImgAuthBeforeStream', array( &$title, &$path, &$name, &$result ) ) ) {
 108                 wfForbidden( $result[0], $result[1], array_slice( $result, 2 ) );
 109                 return;
 110         }
 111
 112         // Check user authorization for this title
 113         // Checks Whitelist too
 114         if ( !$title->userCan( 'read' ) ) {
 115                 wfForbidden( 'img-auth-accessdenied', 'img-auth-noread', $name );
 116                 return;
 117         }
 118
 119         // Stream the requested file
 120         wfDebugLog( 'img_auth', "Streaming `".$filename."`." );
 121         $repo->streamFile( $filename, array( 'Cache-Control: private', 'Vary: Cookie' ) );
 122 }
 123
 124 /**
 125  * Issue a standard HTTP 403 Forbidden header ($msg1-a message index, not a message) and an
 126  * error message ($msg2, also a message index), (both required) then end the script
 127  * subsequent arguments to $msg2 will be passed as parameters only for replacing in $msg2
 128  * @param $msg1
 129  * @param $msg2
 130  */
 131 function wfForbidden( $msg1, $msg2 ) {
 132         global $wgImgAuthDetails;
 133
 134         $args = func_get_args();
 135         array_shift( $args );
 136         array_shift( $args );
 137
 138         $msgHdr = htmlspecialchars( wfMsg( $msg1 ) );
 139         $detailMsgKey = $wgImgAuthDetails ? $msg2 : 'badaccess-group0';
 140         $detailMsg = htmlspecialchars( wfMsg( $detailMsgKey, $args ) );
 141
 142         wfDebugLog( 'img_auth',
 143                 "wfForbidden Hdr:" . wfMsgExt( $msg1, array( 'language' => 'en' ) ). " Msg: ".
 144                 wfMsgExt( $msg2, array( 'language' => 'en' ), $args )
 145         );
 146
 147         header( 'HTTP/1.0 403 Forbidden' );
 148         header( 'Cache-Control: no-cache' );
 149         header( 'Content-Type: text/html; charset=utf-8' );
 150         echo <<<ENDS
 151 <html>
 152 <body>
 153 <h1>$msgHdr</h1>
 154 <p>$detailMsg</p>
 155 </body>
 156 </html>
 157 ENDS;
 158 }