img_auth.php

Go to the documentation of this file.

<?php
define( 'MW_NO_OUTPUT_COMPRESSION', 1 );
require __DIR__ . '/includes/WebStart.php';
wfProfileIn( 'img_auth.php' );
 
# Set action base paths so that WebRequest::getPathInfo()
# recognizes the "X" as the 'title' in ../img_auth.php/X urls.
$wgArticlePath = false; # Don't let a "/*" article path clober our action path
$wgActionPaths = array( "$wgUploadPath/" );
 
wfImageAuthMain();
wfLogProfilingData();
// Commit and close up!
$factory = wfGetLBFactory();
$factory->commitMasterChanges();
$factory->shutdown();
 
function wfImageAuthMain() {
    global $wgImgAuthPublicTest, $wgImgAuthUrlPathMap, $wgRequest;
 
    // See if this is a public Wiki (no protections).
    if ( $wgImgAuthPublicTest
        && in_array( 'read', User::getGroupPermissions( array( '*' ) ), true )
    ) {
        // This is a public wiki, so disable this script (for private wikis only)
        wfForbidden( 'img-auth-accessdenied', 'img-auth-public' );
        return;
    }
 
    // Get the requested file path (source file or thumbnail)
    $matches = WebRequest::getPathInfo();
    if ( !isset( $matches['title'] ) ) {
        wfForbidden( 'img-auth-accessdenied', 'img-auth-nopathinfo' );
        return;
    }
    $path = $matches['title'];
    if ( $path && $path[0] !== '/' ) {
        // Make sure $path has a leading /
        $path = "/" . $path;
    }
 
    // Check for bug 28235: QUERY_STRING overriding the correct extension
    $whitelist = array();
    $extension = FileBackend::extensionFromPath( $path );
    if ( $extension != '' ) {
        $whitelist[] = $extension;
    }
    if ( !$wgRequest->checkUrlExtension( $whitelist ) ) {
        return;
    }
 
    // 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 = FileBackendGroup::singleton()->backendFromPath( $storageDir );
            $filename = $storageDir . substr( $path, strlen( $prefix ) ); // strip prefix
            // Check basic user authorization
            if ( !RequestContext::getMain()->getUser()->isAllowed( 'read' ) ) {
                wfForbidden( 'img-auth-accessdenied', 'img-auth-noread', $path );
                return;
            }
            if ( $be->fileExists( array( 'src' => $filename ) ) ) {
                wfDebugLog( 'img_auth', "Streaming `" . $filename . "`." );
                $be->streamFile( array( 'src' => $filename ),
                    array( 'Cache-Control: private', 'Vary: Cookie' ) );
            } else {
                wfForbidden( 'img-auth-accessdenied', 'img-auth-nofile', $path );
            }
            return;
        }
    }
 
    // Get the local file repository
    $repo = RepoGroup::singleton()->getRepo( 'local' );
 
    // 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, and all thumbnails should
    // be under a folder that has the source file name.
    if ( strpos( $path, '/thumb/' ) === 0 ) {
        $name = wfBaseName( dirname( $path ) ); // file is a thumbnail
        $filename = $repo->getZonePath( 'thumb' ) . substr( $path, 6 ); // strip "/thumb"
    } else {
        $name = wfBaseName( $path ); // file is a source file
        $filename = $repo->getZonePath( 'public' ) . $path;
    }
 
    // Check to see if the file exists
    if ( !$repo->fileExists( $filename ) ) {
        wfForbidden( 'img-auth-accessdenied', 'img-auth-nofile', $filename );
        return;
    }
 
    $title = Title::makeTitleSafe( NS_FILE, $name );
    if ( !$title instanceof Title ) { // files have valid titles
        wfForbidden( 'img-auth-accessdenied', 'img-auth-badtitle', $name );
        return;
    }
 
    // Run hook for extension authorization plugins
    $result = null;
    if ( !wfRunHooks( 'ImgAuthBeforeStream', array( &$title, &$path, &$name, &$result ) ) ) {
        wfForbidden( $result[0], $result[1], array_slice( $result, 2 ) );
        return;
    }
 
    // Check user authorization for this title
    // Checks Whitelist too
    if ( !$title->userCan( 'read' ) ) {
        wfForbidden( 'img-auth-accessdenied', 'img-auth-noread', $name );
        return;
    }
 
    if ( $wgRequest->getCheck( 'download' ) ) {
        header( 'Content-Disposition: attachment' );
    }
 
    // Stream the requested file
    wfDebugLog( 'img_auth', "Streaming `" . $filename . "`." );
    $repo->streamFile( $filename, array( 'Cache-Control: private', 'Vary: Cookie' ) );
}
 
function wfForbidden( $msg1, $msg2 ) {
    global $wgImgAuthDetails;
 
    $args = func_get_args();
    array_shift( $args );
    array_shift( $args );
    $args = ( isset( $args[0] ) && is_array( $args[0] ) ) ? $args[0] : $args;
 
    $msgHdr = wfMessage( $msg1 )->escaped();
    $detailMsgKey = $wgImgAuthDetails ? $msg2 : 'badaccess-group0';
    $detailMsg = wfMessage( $detailMsgKey, $args )->escaped();
 
    wfDebugLog( 'img_auth',
        "wfForbidden Hdr: " . wfMessage( $msg1 )->inLanguage( 'en' )->text() . " Msg: " .
            wfMessage( $msg2, $args )->inLanguage( 'en' )->text()
    );
 
    header( 'HTTP/1.0 403 Forbidden' );
    header( 'Cache-Control: no-cache' );
    header( 'Content-Type: text/html; charset=utf-8' );
    echo <<<ENDS
<html>
<body>
<h1>$msgHdr</h1>
<p>$detailMsg</p>
</body>
</html>
ENDS;
}