wiki.techinc.nl/includes/upload/UploadBase.php

1220 lines
36 KiB
PHP

<?php
/**
* @file
* @ingroup upload
*
* UploadBase and subclasses are the backend of MediaWiki's file uploads.
* The frontends are formed by ApiUpload and SpecialUpload.
*
* See also includes/docs/upload.txt
*
* @author Brion Vibber
* @author Bryan Tong Minh
* @author Michael Dale
*/
abstract class UploadBase {
protected $mTempPath;
protected $mDesiredDestName, $mDestName, $mRemoveTempFile, $mSourceType;
protected $mTitle = false, $mTitleError = 0;
protected $mFilteredName, $mFinalExtension;
protected $mLocalFile;
const SUCCESS = 0;
const OK = 0;
const EMPTY_FILE = 3;
const MIN_LENGTH_PARTNAME = 4;
const ILLEGAL_FILENAME = 5;
const OVERWRITE_EXISTING_FILE = 7; # Not used anymore; handled by verifyPermissions()
const FILETYPE_MISSING = 8;
const FILETYPE_BADTYPE = 9;
const VERIFICATION_ERROR = 10;
# HOOK_ABORTED is the new name of UPLOAD_VERIFICATION_ERROR
const UPLOAD_VERIFICATION_ERROR = 11;
const HOOK_ABORTED = 11;
const FILE_TOO_LARGE = 12;
const SESSION_VERSION = 2;
const SESSION_KEYNAME = 'wsUploadData';
static public function getSessionKeyname() {
return self::SESSION_KEYNAME;
}
public function getVerificationErrorCode( $error ) {
$code_to_status = array(self::EMPTY_FILE => 'empty-file',
self::FILE_TOO_LARGE => 'file-too-large',
self::FILETYPE_MISSING => 'filetype-missing',
self::FILETYPE_BADTYPE => 'filetype-banned',
self::MIN_LENGTH_PARTNAME => 'filename-tooshort',
self::ILLEGAL_FILENAME => 'illegal-filename',
self::OVERWRITE_EXISTING_FILE => 'overwrite',
self::VERIFICATION_ERROR => 'verification-error',
self::HOOK_ABORTED => 'hookaborted',
);
if( isset( $code_to_status[$error] ) ) {
return $code_to_status[$error];
}
return 'unknown-error';
}
/**
* Returns true if uploads are enabled.
* Can be override by subclasses.
*/
public static function isEnabled() {
global $wgEnableUploads;
if ( !$wgEnableUploads ) {
return false;
}
# Check php's file_uploads setting
if( !wfIniGetBool( 'file_uploads' ) ) {
return false;
}
return true;
}
/**
* Returns an array of permissions that is required to upload a file
*
* @return array
*/
public static function getRequiredPermissions() {
return array( 'upload', 'edit' );
}
/**
* Returns true if the user can use this upload module or else a string
* identifying the missing permission.
* Can be overriden by subclasses.
*/
public static function isAllowed( $user ) {
foreach ( self::getRequiredPermissions() as $permission ) {
if ( !$user->isAllowed( $permission ) ) {
return $permission;
}
}
return true;
}
// Upload handlers. Should probably just be a global.
static $uploadHandlers = array( 'Stash', 'File', 'Url' );
/**
* Create a form of UploadBase depending on wpSourceType and initializes it
*/
public static function createFromRequest( &$request, $type = null ) {
$type = $type ? $type : $request->getVal( 'wpSourceType', 'File' );
if( !$type ) {
return null;
}
// Get the upload class
$type = ucfirst( $type );
// Give hooks the chance to handle this request
$className = null;
wfRunHooks( 'UploadCreateFromRequest', array( $type, &$className ) );
if ( is_null( $className ) ) {
$className = 'UploadFrom' . $type;
wfDebug( __METHOD__ . ": class name: $className\n" );
if( !in_array( $type, self::$uploadHandlers ) ) {
return null;
}
}
// Check whether this upload class is enabled
if( !call_user_func( array( $className, 'isEnabled' ) ) ) {
return null;
}
// Check whether the request is valid
if( !call_user_func( array( $className, 'isValidRequest' ), $request ) ) {
return null;
}
$handler = new $className;
$handler->initializeFromRequest( $request );
return $handler;
}
/**
* Check whether a request if valid for this handler
*/
public static function isValidRequest( $request ) {
return false;
}
public function __construct() {}
/**
* Initialize the path information
* @param $name string the desired destination name
* @param $tempPath string the temporary path
* @param $fileSize int the file size
* @param $removeTempFile bool (false) remove the temporary file?
* @return null
*/
public function initializePathInfo( $name, $tempPath, $fileSize, $removeTempFile = false ) {
$this->mDesiredDestName = $name;
$this->mTempPath = $tempPath;
$this->mFileSize = $fileSize;
$this->mRemoveTempFile = $removeTempFile;
}
/**
* Initialize from a WebRequest. Override this in a subclass.
*/
public abstract function initializeFromRequest( &$request );
/**
* Fetch the file. Usually a no-op
*/
public function fetchFile() {
return Status::newGood();
}
/**
* Return true if the file is empty
* @return bool
*/
public function isEmptyFile() {
return empty( $this->mFileSize );
}
/**
* Return the file size
* @return integer
*/
public function getFileSize() {
return $this->mFileSize;
}
/**
* Append a file to the Repo file
*
* @param $srcPath String: path to source file
* @param $toAppendPath String: path to the Repo file that will be appended to.
* @return Status Status
*/
protected function appendToUploadFile( $srcPath, $toAppendPath ) {
$repo = RepoGroup::singleton()->getLocalRepo();
$status = $repo->append( $srcPath, $toAppendPath );
return $status;
}
/**
* @param $srcPath String: the source path
* @return the real path if it was a virtual URL
*/
function getRealPath( $srcPath ) {
$repo = RepoGroup::singleton()->getLocalRepo();
if ( $repo->isVirtualUrl( $srcPath ) ) {
return $repo->resolveVirtualUrl( $srcPath );
}
return $srcPath;
}
/**
* Verify whether the upload is sane.
* @return mixed self::OK or else an array with error information
*/
public function verifyUpload() {
/**
* If there was no filename or a zero size given, give up quick.
*/
if( $this->isEmptyFile() ) {
return array( 'status' => self::EMPTY_FILE );
}
/**
* Honor $wgMaxUploadSize
*/
global $wgMaxUploadSize;
if( $this->mFileSize > $wgMaxUploadSize ) {
return array(
'status' => self::FILE_TOO_LARGE,
'max' => $wgMaxUploadSize,
);
}
/**
* Look at the contents of the file; if we can recognize the
* type but it's corrupt or data of the wrong type, we should
* probably not accept it.
*/
$verification = $this->verifyFile();
if( $verification !== true ) {
return array(
'status' => self::VERIFICATION_ERROR,
'details' => $verification
);
}
/**
* Make sure this file can be created
*/
$result = $this->validateName();
if( $result !== true ) {
return $result;
}
$error = '';
if( !wfRunHooks( 'UploadVerification',
array( $this->mDestName, $this->mTempPath, &$error ) ) ) {
return array( 'status' => self::HOOK_ABORTED, 'error' => $error );
}
return array( 'status' => self::OK );
}
/**
* Verify that the name is valid and, if necessary, that we can overwrite
*
* @return mixed true if valid, otherwise and array with 'status'
* and other keys
**/
protected function validateName() {
$nt = $this->getTitle();
if( is_null( $nt ) ) {
$result = array( 'status' => $this->mTitleError );
if( $this->mTitleError == self::ILLEGAL_FILENAME ) {
$result['filtered'] = $this->mFilteredName;
}
if ( $this->mTitleError == self::FILETYPE_BADTYPE ) {
$result['finalExt'] = $this->mFinalExtension;
}
return $result;
}
$this->mDestName = $this->getLocalFile()->getName();
return true;
}
/**
* Verify the mime type
*
* @param $mime string representing the mime
* @return mixed true if the file is verified, an array otherwise
*/
protected function verifyMimeType( $mime ) {
global $wgVerifyMimeType;
if ( $wgVerifyMimeType ) {
wfDebug ( "\n\nmime: <$mime> extension: <{$this->mFinalExtension}>\n\n");
if ( !$this->verifyExtension( $mime, $this->mFinalExtension ) ) {
return array( 'filetype-mime-mismatch' );
}
global $wgMimeTypeBlacklist;
if ( $this->checkFileExtension( $mime, $wgMimeTypeBlacklist ) ) {
return array( 'filetype-badmime', $mime );
}
# Check IE type
$fp = fopen( $this->mTempPath, 'rb' );
$chunk = fread( $fp, 256 );
fclose( $fp );
$magic = MimeMagic::singleton();
$extMime = $magic->guessTypesForExtension( $this->mFinalExtension );
$ieTypes = $magic->getIEMimeTypes( $this->mTempPath, $chunk, $extMime );
foreach ( $ieTypes as $ieType ) {
if ( $this->checkFileExtension( $ieType, $wgMimeTypeBlacklist ) ) {
return array( 'filetype-bad-ie-mime', $ieType );
}
}
}
return true;
}
/**
* Verifies that it's ok to include the uploaded file
*
* @return mixed true of the file is verified, array otherwise.
*/
protected function verifyFile() {
# get the title, even though we are doing nothing with it, because
# we need to populate mFinalExtension
$nt = $this->getTitle();
$this->mFileProps = File::getPropsFromPath( $this->mTempPath, $this->mFinalExtension );
$this->checkMacBinary();
# check mime type, if desired
$mime = $this->mFileProps[ 'file-mime' ];
$status = $this->verifyMimeType( $mime );
if ( $status !== true ) {
return $status;
}
# check for htmlish code and javascript
if( self::detectScript( $this->mTempPath, $mime, $this->mFinalExtension ) ) {
return array( 'uploadscripted' );
}
if( $this->mFinalExtension == 'svg' || $mime == 'image/svg+xml' ) {
if( $this->detectScriptInSvg( $this->mTempPath ) ) {
return array( 'uploadscripted' );
}
}
/**
* Scan the uploaded file for viruses
*/
$virus = $this->detectVirus( $this->mTempPath );
if ( $virus ) {
return array( 'uploadvirus', $virus );
}
$handler = MediaHandler::getHandler( $mime );
if ( $handler ) {
$handlerStatus = $handler->verifyUpload( $this->mTempPath );
if ( !$handlerStatus->isOK() ) {
$errors = $handlerStatus->getErrorsArray();
return reset( $errors );
}
}
wfRunHooks( 'UploadVerifyFile', array( $this, $mime, &$status ) );
if ( $status !== true ) {
return $status;
}
wfDebug( __METHOD__ . ": all clear; passing.\n" );
return true;
}
/**
* Check whether the user can edit, upload and create the image. This
* checks only against the current title; if it returns errors, it may
* very well be that another title will not give errors. Therefore
* isAllowed() should be called as well for generic is-user-blocked or
* can-user-upload checking.
*
* @param $user the User object to verify the permissions against
* @return mixed An array as returned by getUserPermissionsErrors or true
* in case the user has proper permissions.
*/
public function verifyPermissions( $user ) {
/**
* If the image is protected, non-sysop users won't be able
* to modify it by uploading a new revision.
*/
$nt = $this->getTitle();
if( is_null( $nt ) ) {
return true;
}
$permErrors = $nt->getUserPermissionsErrors( 'edit', $user );
$permErrorsUpload = $nt->getUserPermissionsErrors( 'upload', $user );
if ( $nt->exists() ) {
$permErrorsCreate = $nt->getUserPermissionsErrors( 'createpage', $user );
} else {
$permErrorsCreate = array();
}
if( $permErrors || $permErrorsUpload || $permErrorsCreate ) {
$permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsUpload, $permErrors ) );
$permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsCreate, $permErrors ) );
return $permErrors;
}
$overwriteError = $this->checkOverwrite( $user );
if ( $overwriteError !== true ) {
return array( array( $overwriteError ) );
}
return true;
}
/**
* Check for non fatal problems with the file
*
* @return Array of warnings
*/
public function checkWarnings() {
$warnings = array();
$localFile = $this->getLocalFile();
$filename = $localFile->getName();
$n = strrpos( $filename, '.' );
$partname = $n ? substr( $filename, 0, $n ) : $filename;
/**
* Check whether the resulting filename is different from the desired one,
* but ignore things like ucfirst() and spaces/underscore things
*/
$comparableName = str_replace( ' ', '_', $this->mDesiredDestName );
$comparableName = Title::capitalize( $comparableName, NS_FILE );
if( $this->mDesiredDestName != $filename && $comparableName != $filename ) {
$warnings['badfilename'] = $filename;
}
// Check whether the file extension is on the unwanted list
global $wgCheckFileExtensions, $wgFileExtensions;
if ( $wgCheckFileExtensions ) {
if ( !$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) ) {
$warnings['filetype-unwanted-type'] = $this->mFinalExtension;
}
}
global $wgUploadSizeWarning;
if ( $wgUploadSizeWarning && ( $this->mFileSize > $wgUploadSizeWarning ) ) {
$warnings['large-file'] = $wgUploadSizeWarning;
}
if ( $this->mFileSize == 0 ) {
$warnings['emptyfile'] = true;
}
$exists = self::getExistsWarning( $localFile );
if( $exists !== false ) {
$warnings['exists'] = $exists;
}
// Check dupes against existing files
$hash = File::sha1Base36( $this->mTempPath );
$dupes = RepoGroup::singleton()->findBySha1( $hash );
$title = $this->getTitle();
// Remove all matches against self
foreach ( $dupes as $key => $dupe ) {
if( $title->equals( $dupe->getTitle() ) ) {
unset( $dupes[$key] );
}
}
if( $dupes ) {
$warnings['duplicate'] = $dupes;
}
// Check dupes against archives
$archivedImage = new ArchivedFile( null, 0, "{$hash}.{$this->mFinalExtension}" );
if ( $archivedImage->getID() > 0 ) {
$warnings['duplicate-archive'] = $archivedImage->getName();
}
return $warnings;
}
/**
* Really perform the upload. Stores the file in the local repo, watches
* if necessary and runs the UploadComplete hook.
*
* @return mixed Status indicating the whether the upload succeeded.
*/
public function performUpload( $comment, $pageText, $watch, $user ) {
wfDebug( "\n\n\performUpload: sum: " . $comment . ' c: ' . $pageText .
' w: ' . $watch );
$status = $this->getLocalFile()->upload( $this->mTempPath, $comment, $pageText,
File::DELETE_SOURCE, $this->mFileProps, false, $user );
if( $status->isGood() ) {
if ( $watch ) {
$user->addWatch( $this->getLocalFile()->getTitle() );
}
wfRunHooks( 'UploadComplete', array( &$this ) );
}
return $status;
}
/**
* Returns the title of the file to be uploaded. Sets mTitleError in case
* the name was illegal.
*
* @return Title The title of the file or null in case the name was illegal
*/
public function getTitle() {
if ( $this->mTitle !== false ) {
return $this->mTitle;
}
/**
* Chop off any directories in the given filename. Then
* filter out illegal characters, and try to make a legible name
* out of it. We'll strip some silently that Title would die on.
*/
$this->mFilteredName = wfStripIllegalFilenameChars( $this->mDesiredDestName );
/* Normalize to title form before we do any further processing */
$nt = Title::makeTitleSafe( NS_FILE, $this->mFilteredName );
if( is_null( $nt ) ) {
$this->mTitleError = self::ILLEGAL_FILENAME;
return $this->mTitle = null;
}
$this->mFilteredName = $nt->getDBkey();
/**
* We'll want to blacklist against *any* 'extension', and use
* only the final one for the whitelist.
*/
list( $partname, $ext ) = $this->splitExtensions( $this->mFilteredName );
if( count( $ext ) ) {
$this->mFinalExtension = trim( $ext[count( $ext ) - 1] );
} else {
$this->mFinalExtension = '';
}
/* Don't allow users to override the blacklist (check file extension) */
global $wgCheckFileExtensions, $wgStrictFileExtensions;
global $wgFileExtensions, $wgFileBlacklist;
if ( $this->mFinalExtension == '' ) {
$this->mTitleError = self::FILETYPE_MISSING;
return $this->mTitle = null;
} elseif ( $this->checkFileExtensionList( $ext, $wgFileBlacklist ) ||
( $wgCheckFileExtensions && $wgStrictFileExtensions &&
!$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) ) ) {
$this->mTitleError = self::FILETYPE_BADTYPE;
return $this->mTitle = null;
}
# If there was more than one "extension", reassemble the base
# filename to prevent bogus complaints about length
if( count( $ext ) > 1 ) {
for( $i = 0; $i < count( $ext ) - 1; $i++ ) {
$partname .= '.' . $ext[$i];
}
}
if( strlen( $partname ) < 1 ) {
$this->mTitleError = self::MIN_LENGTH_PARTNAME;
return $this->mTitle = null;
}
return $this->mTitle = $nt;
}
/**
* Return the local file and initializes if necessary.
*/
public function getLocalFile() {
if( is_null( $this->mLocalFile ) ) {
$nt = $this->getTitle();
$this->mLocalFile = is_null( $nt ) ? null : wfLocalFile( $nt );
}
return $this->mLocalFile;
}
/**
* NOTE: Probably should be deprecated in favor of UploadStash, but this is sometimes
* called outside that context.
*
* Stash a file in a temporary directory for later processing
* after the user has confirmed it.
*
* If the user doesn't explicitly cancel or accept, these files
* can accumulate in the temp directory.
*
* @param $saveName String: the destination filename
* @param $tempSrc String: the source temporary file to save
* @return String: full path the stashed file, or false on failure
*/
protected function saveTempUploadedFile( $saveName, $tempSrc ) {
$repo = RepoGroup::singleton()->getLocalRepo();
$status = $repo->storeTemp( $saveName, $tempSrc );
return $status;
}
/**
* If the user does not supply all necessary information in the first upload form submission (either by accident or
* by design) then we may want to stash the file temporarily, get more information, and publish the file later.
*
* This method will stash a file in a temporary directory for later processing, and save the necessary descriptive info
* into the user's session.
* This method returns the file object, which also has a 'sessionKey' property which can be passed through a form or
* API request to find this stashed file again.
*
* @param {String}: $key (optional) the session key used to find the file info again. If not supplied, a key will be autogenerated.
* @return {File}: stashed file
*/
public function stashSessionFile( $key = null ) {
$stash = new UploadStash();
$data = array(
'mFileProps' => $this->mFileProps
);
$file = $stash->stashFile( $this->mTempPath, $data, $key );
// TODO should we change the "local file" here?
// $this->mLocalFile = $file;
return $file;
}
/**
* Stash a file in a temporary directory, returning a key which can be used to find the file again. See stashSessionFile().
*
* @param {String}: $key (optional) the session key used to find the file info again. If not supplied, a key will be autogenerated.
* @return {String}: session key
*/
public function stashSession( $key = null ) {
return $this->stashSessionFile( $key )->getSessionKey();
}
/**
* If we've modified the upload file we need to manually remove it
* on exit to clean up.
*/
public function cleanupTempFile() {
if ( $this->mRemoveTempFile && $this->mTempPath && file_exists( $this->mTempPath ) ) {
wfDebug( __METHOD__ . ": Removing temporary file {$this->mTempPath}\n" );
unlink( $this->mTempPath );
}
}
public function getTempPath() {
return $this->mTempPath;
}
/**
* Split a file into a base name and all dot-delimited 'extensions'
* on the end. Some web server configurations will fall back to
* earlier pseudo-'extensions' to determine type and execute
* scripts, so the blacklist needs to check them all.
*
* @return array
*/
public static function splitExtensions( $filename ) {
$bits = explode( '.', $filename );
$basename = array_shift( $bits );
return array( $basename, $bits );
}
/**
* Perform case-insensitive match against a list of file extensions.
* Returns true if the extension is in the list.
*
* @param $ext String
* @param $list Array
* @return Boolean
*/
public static function checkFileExtension( $ext, $list ) {
return in_array( strtolower( $ext ), $list );
}
/**
* Perform case-insensitive match against a list of file extensions.
* Returns true if any of the extensions are in the list.
*
* @param $ext Array
* @param $list Array
* @return Boolean
*/
public static function checkFileExtensionList( $ext, $list ) {
foreach( $ext as $e ) {
if( in_array( strtolower( $e ), $list ) ) {
return true;
}
}
return false;
}
/**
* Checks if the mime type of the uploaded file matches the file extension.
*
* @param $mime String: the mime type of the uploaded file
* @param $extension String: the filename extension that the file is to be served with
* @return Boolean
*/
public static function verifyExtension( $mime, $extension ) {
$magic = MimeMagic::singleton();
if ( !$mime || $mime == 'unknown' || $mime == 'unknown/unknown' )
if ( !$magic->isRecognizableExtension( $extension ) ) {
wfDebug( __METHOD__ . ": passing file with unknown detected mime type; " .
"unrecognized extension '$extension', can't verify\n" );
return true;
} else {
wfDebug( __METHOD__ . ": rejecting file with unknown detected mime type; ".
"recognized extension '$extension', so probably invalid file\n" );
return false;
}
$match = $magic->isMatchingExtension( $extension, $mime );
if ( $match === null ) {
wfDebug( __METHOD__ . ": no file extension known for mime type $mime, passing file\n" );
return true;
} elseif( $match === true ) {
wfDebug( __METHOD__ . ": mime type $mime matches extension $extension, passing file\n" );
#TODO: if it's a bitmap, make sure PHP or ImageMagic resp. can handle it!
return true;
} else {
wfDebug( __METHOD__ . ": mime type $mime mismatches file extension $extension, rejecting file\n" );
return false;
}
}
/**
* Heuristic for detecting files that *could* contain JavaScript instructions or
* things that may look like HTML to a browser and are thus
* potentially harmful. The present implementation will produce false
* positives in some situations.
*
* @param $file String: pathname to the temporary upload file
* @param $mime String: the mime type of the file
* @param $extension String: the extension of the file
* @return Boolean: true if the file contains something looking like embedded scripts
*/
public static function detectScript( $file, $mime, $extension ) {
global $wgAllowTitlesInSVG;
# ugly hack: for text files, always look at the entire file.
# For binary field, just check the first K.
if( strpos( $mime,'text/' ) === 0 ) {
$chunk = file_get_contents( $file );
} else {
$fp = fopen( $file, 'rb' );
$chunk = fread( $fp, 1024 );
fclose( $fp );
}
$chunk = strtolower( $chunk );
if( !$chunk ) {
return false;
}
# decode from UTF-16 if needed (could be used for obfuscation).
if( substr( $chunk, 0, 2 ) == "\xfe\xff" ) {
$enc = 'UTF-16BE';
} elseif( substr( $chunk, 0, 2 ) == "\xff\xfe" ) {
$enc = 'UTF-16LE';
} else {
$enc = null;
}
if( $enc ) {
$chunk = iconv( $enc, "ASCII//IGNORE", $chunk );
}
$chunk = trim( $chunk );
# FIXME: convert from UTF-16 if necessarry!
wfDebug( __METHOD__ . ": checking for embedded scripts and HTML stuff\n" );
# check for HTML doctype
if ( preg_match( "/<!DOCTYPE *X?HTML/i", $chunk ) ) {
return true;
}
/**
* Internet Explorer for Windows performs some really stupid file type
* autodetection which can cause it to interpret valid image files as HTML
* and potentially execute JavaScript, creating a cross-site scripting
* attack vectors.
*
* Apple's Safari browser also performs some unsafe file type autodetection
* which can cause legitimate files to be interpreted as HTML if the
* web server is not correctly configured to send the right content-type
* (or if you're really uploading plain text and octet streams!)
*
* Returns true if IE is likely to mistake the given file for HTML.
* Also returns true if Safari would mistake the given file for HTML
* when served with a generic content-type.
*/
$tags = array(
'<a href',
'<body',
'<head',
'<html', #also in safari
'<img',
'<pre',
'<script', #also in safari
'<table'
);
if( !$wgAllowTitlesInSVG && $extension !== 'svg' && $mime !== 'image/svg' ) {
$tags[] = '<title';
}
foreach( $tags as $tag ) {
if( false !== strpos( $chunk, $tag ) ) {
return true;
}
}
/*
* look for JavaScript
*/
# resolve entity-refs to look at attributes. may be harsh on big files... cache result?
$chunk = Sanitizer::decodeCharReferences( $chunk );
# look for script-types
if( preg_match( '!type\s*=\s*[\'"]?\s*(?:\w*/)?(?:ecma|java)!sim', $chunk ) ) {
return true;
}
# look for html-style script-urls
if( preg_match( '!(?:href|src|data)\s*=\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
return true;
}
# look for css-style script-urls
if( preg_match( '!url\s*\(\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
return true;
}
wfDebug( __METHOD__ . ": no scripts found\n" );
return false;
}
protected function detectScriptInSvg( $filename ) {
$check = new XmlTypeCheck( $filename, array( $this, 'checkSvgScriptCallback' ) );
return $check->filterMatch;
}
/**
* @todo Replace this with a whitelist filter!
*/
public function checkSvgScriptCallback( $element, $attribs ) {
$stripped = $this->stripXmlNamespace( $element );
if( $stripped == 'script' ) {
wfDebug( __METHOD__ . ": Found script element '$element' in uploaded file.\n" );
return true;
}
foreach( $attribs as $attrib => $value ) {
$stripped = $this->stripXmlNamespace( $attrib );
if( substr( $stripped, 0, 2 ) == 'on' ) {
wfDebug( __METHOD__ . ": Found script attribute '$attrib'='value' in uploaded file.\n" );
return true;
}
if( $stripped == 'href' && strpos( strtolower( $value ), 'javascript:' ) !== false ) {
wfDebug( __METHOD__ . ": Found script href attribute '$attrib'='$value' in uploaded file.\n" );
return true;
}
}
}
private function stripXmlNamespace( $name ) {
// 'http://www.w3.org/2000/svg:script' -> 'script'
$parts = explode( ':', strtolower( $name ) );
return array_pop( $parts );
}
/**
* Generic wrapper function for a virus scanner program.
* This relies on the $wgAntivirus and $wgAntivirusSetup variables.
* $wgAntivirusRequired may be used to deny upload if the scan fails.
*
* @param $file String: pathname to the temporary upload file
* @return mixed false if not virus is found, NULL if the scan fails or is disabled,
* or a string containing feedback from the virus scanner if a virus was found.
* If textual feedback is missing but a virus was found, this function returns true.
*/
public static function detectVirus( $file ) {
global $wgAntivirus, $wgAntivirusSetup, $wgAntivirusRequired, $wgOut;
if ( !$wgAntivirus ) {
wfDebug( __METHOD__ . ": virus scanner disabled\n" );
return null;
}
if ( !$wgAntivirusSetup[$wgAntivirus] ) {
wfDebug( __METHOD__ . ": unknown virus scanner: $wgAntivirus\n" );
$wgOut->wrapWikiMsg( "<div class=\"error\">\n$1\n</div>",
array( 'virus-badscanner', $wgAntivirus ) );
return wfMsg( 'virus-unknownscanner' ) . " $wgAntivirus";
}
# look up scanner configuration
$command = $wgAntivirusSetup[$wgAntivirus]['command'];
$exitCodeMap = $wgAntivirusSetup[$wgAntivirus]['codemap'];
$msgPattern = isset( $wgAntivirusSetup[$wgAntivirus]['messagepattern'] ) ?
$wgAntivirusSetup[$wgAntivirus]['messagepattern'] : null;
if ( strpos( $command, "%f" ) === false ) {
# simple pattern: append file to scan
$command .= " " . wfEscapeShellArg( $file );
} else {
# complex pattern: replace "%f" with file to scan
$command = str_replace( "%f", wfEscapeShellArg( $file ), $command );
}
wfDebug( __METHOD__ . ": running virus scan: $command \n" );
# execute virus scanner
$exitCode = false;
# NOTE: there's a 50 line workaround to make stderr redirection work on windows, too.
# that does not seem to be worth the pain.
# Ask me (Duesentrieb) about it if it's ever needed.
$output = wfShellExec( "$command 2>&1", $exitCode );
# map exit code to AV_xxx constants.
$mappedCode = $exitCode;
if ( $exitCodeMap ) {
if ( isset( $exitCodeMap[$exitCode] ) ) {
$mappedCode = $exitCodeMap[$exitCode];
} elseif ( isset( $exitCodeMap["*"] ) ) {
$mappedCode = $exitCodeMap["*"];
}
}
if ( $mappedCode === AV_SCAN_FAILED ) {
# scan failed (code was mapped to false by $exitCodeMap)
wfDebug( __METHOD__ . ": failed to scan $file (code $exitCode).\n" );
if ( $wgAntivirusRequired ) {
return wfMsg( 'virus-scanfailed', array( $exitCode ) );
} else {
return null;
}
} elseif ( $mappedCode === AV_SCAN_ABORTED ) {
# scan failed because filetype is unknown (probably imune)
wfDebug( __METHOD__ . ": unsupported file type $file (code $exitCode).\n" );
return null;
} elseif ( $mappedCode === AV_NO_VIRUS ) {
# no virus found
wfDebug( __METHOD__ . ": file passed virus scan.\n" );
return false;
} else {
$output = trim( $output );
if ( !$output ) {
$output = true; #if there's no output, return true
} elseif ( $msgPattern ) {
$groups = array();
if ( preg_match( $msgPattern, $output, $groups ) ) {
if ( $groups[1] ) {
$output = $groups[1];
}
}
}
wfDebug( __METHOD__ . ": FOUND VIRUS! scanner feedback: $output \n" );
return $output;
}
}
/**
* Check if the temporary file is MacBinary-encoded, as some uploads
* from Internet Explorer on Mac OS Classic and Mac OS X will be.
* If so, the data fork will be extracted to a second temporary file,
* which will then be checked for validity and either kept or discarded.
*/
private function checkMacBinary() {
$macbin = new MacBinary( $this->mTempPath );
if( $macbin->isValid() ) {
$dataFile = tempnam( wfTempDir(), 'WikiMacBinary' );
$dataHandle = fopen( $dataFile, 'wb' );
wfDebug( __METHOD__ . ": Extracting MacBinary data fork to $dataFile\n" );
$macbin->extractData( $dataHandle );
$this->mTempPath = $dataFile;
$this->mFileSize = $macbin->dataForkLength();
// We'll have to manually remove the new file if it's not kept.
$this->mRemoveTempFile = true;
}
$macbin->close();
}
/**
* Check if there's an overwrite conflict and, if so, if restrictions
* forbid this user from performing the upload.
*
* @return mixed true on success, error string on failure
*/
private function checkOverwrite( $user ) {
// First check whether the local file can be overwritten
$file = $this->getLocalFile();
if( $file->exists() ) {
if( !self::userCanReUpload( $user, $file ) ) {
return 'fileexists-forbidden';
} else {
return true;
}
}
/* Check shared conflicts: if the local file does not exist, but
* wfFindFile finds a file, it exists in a shared repository.
*/
$file = wfFindFile( $this->getTitle() );
if ( $file && !$user->isAllowed( 'reupload-shared' ) ) {
return 'fileexists-shared-forbidden';
}
return true;
}
/**
* Check if a user is the last uploader
*
* @param $user User object
* @param $img String: image name
* @return Boolean
*/
public static function userCanReUpload( User $user, $img ) {
if( $user->isAllowed( 'reupload' ) ) {
return true; // non-conditional
}
if( !$user->isAllowed( 'reupload-own' ) ) {
return false;
}
if( is_string( $img ) ) {
$img = wfLocalFile( $img );
}
if ( !( $img instanceof LocalFile ) ) {
return false;
}
return $user->getId() == $img->getUser( 'id' );
}
/**
* Helper function that does various existence checks for a file.
* The following checks are performed:
* - The file exists
* - Article with the same name as the file exists
* - File exists with normalized extension
* - The file looks like a thumbnail and the original exists
*
* @param $file The File object to check
* @return mixed False if the file does not exists, else an array
*/
public static function getExistsWarning( $file ) {
if( $file->exists() ) {
return array( 'warning' => 'exists', 'file' => $file );
}
if( $file->getTitle()->getArticleID() ) {
return array( 'warning' => 'page-exists', 'file' => $file );
}
if ( $file->wasDeleted() && !$file->exists() ) {
return array( 'warning' => 'was-deleted', 'file' => $file );
}
if( strpos( $file->getName(), '.' ) == false ) {
$partname = $file->getName();
$extension = '';
} else {
$n = strrpos( $file->getName(), '.' );
$extension = substr( $file->getName(), $n + 1 );
$partname = substr( $file->getName(), 0, $n );
}
$normalizedExtension = File::normalizeExtension( $extension );
if ( $normalizedExtension != $extension ) {
// We're not using the normalized form of the extension.
// Normal form is lowercase, using most common of alternate
// extensions (eg 'jpg' rather than 'JPEG').
//
// Check for another file using the normalized form...
$nt_lc = Title::makeTitle( NS_FILE, "{$partname}.{$normalizedExtension}" );
$file_lc = wfLocalFile( $nt_lc );
if( $file_lc->exists() ) {
return array(
'warning' => 'exists-normalized',
'file' => $file,
'normalizedFile' => $file_lc
);
}
}
if ( self::isThumbName( $file->getName() ) ) {
# Check for filenames like 50px- or 180px-, these are mostly thumbnails
$nt_thb = Title::newFromText( substr( $partname , strpos( $partname , '-' ) +1 ) . '.' . $extension, NS_FILE );
$file_thb = wfLocalFile( $nt_thb );
if( $file_thb->exists() ) {
return array(
'warning' => 'thumb',
'file' => $file,
'thumbFile' => $file_thb
);
} else {
// File does not exist, but we just don't like the name
return array(
'warning' => 'thumb-name',
'file' => $file,
'thumbFile' => $file_thb
);
}
}
foreach( self::getFilenamePrefixBlacklist() as $prefix ) {
if ( substr( $partname, 0, strlen( $prefix ) ) == $prefix ) {
return array(
'warning' => 'bad-prefix',
'file' => $file,
'prefix' => $prefix
);
}
}
return false;
}
/**
* Helper function that checks whether the filename looks like a thumbnail
*/
public static function isThumbName( $filename ) {
$n = strrpos( $filename, '.' );
$partname = $n ? substr( $filename, 0, $n ) : $filename;
return (
substr( $partname , 3, 3 ) == 'px-' ||
substr( $partname , 2, 3 ) == 'px-'
) &&
preg_match( "/[0-9]{2}/" , substr( $partname , 0, 2 ) );
}
/**
* Get a list of blacklisted filename prefixes from [[MediaWiki:Filename-prefix-blacklist]]
*
* @return array list of prefixes
*/
public static function getFilenamePrefixBlacklist() {
$blacklist = array();
$message = wfMsgForContent( 'filename-prefix-blacklist' );
if( $message && !( wfEmptyMsg( 'filename-prefix-blacklist', $message ) || $message == '-' ) ) {
$lines = explode( "\n", $message );
foreach( $lines as $line ) {
// Remove comment lines
$comment = substr( trim( $line ), 0, 1 );
if ( $comment == '#' || $comment == '' ) {
continue;
}
// Remove additional comments after a prefix
$comment = strpos( $line, '#' );
if ( $comment > 0 ) {
$line = substr( $line, 0, $comment-1 );
}
$blacklist[] = trim( $line );
}
}
return $blacklist;
}
/**
* Gets image info about the file just uploaded.
*
* Also has the effect of setting metadata to be an 'indexed tag name' in returned API result if
* 'metadata' was requested. Oddly, we have to pass the "result" object down just so it can do that
* with the appropriate format, presumably.
*
* @param {ApiResult}
* @return {Array} image info
*/
public function getImageInfo( $result ) {
$file = $this->getLocalFile();
$imParam = ApiQueryImageInfo::getPropertyNames();
return ApiQueryImageInfo::getInfo( $file, array_flip( $imParam ), $result );
}
public function convertVerifyErrorToStatus( $error ) {
$code = $error['status'];
unset( $code['status'] );
return Status::newFatal( $this->getVerificationErrorCode( $code ), $error );
}
}