includes/upload/UploadBase.php

   1 <?php
   2 /**
   3  * @file
   4  * @ingroup upload
   5  *
   6  * UploadBase and subclasses are the backend of MediaWiki's file uploads.
   7  * The frontends are formed by ApiUpload and SpecialUpload.
   8  *
   9  * See also includes/docs/upload.txt
  10  *
  11  * @author Brion Vibber
  12  * @author Bryan Tong Minh
  13  * @author Michael Dale
  14  */
  15
  16 abstract class UploadBase {
  17         protected $mTempPath;
  18         protected $mDesiredDestName, $mDestName, $mRemoveTempFile, $mSourceType;
  19         protected $mTitle = false, $mTitleError = 0;
  20         protected $mFilteredName, $mFinalExtension;
  21         protected $mLocalFile;
  22
  23         const SUCCESS = 0;
  24         const OK = 0;
  25         const EMPTY_FILE = 3;
  26         const MIN_LENGTH_PARTNAME = 4;
  27         const ILLEGAL_FILENAME = 5;
  28         const OVERWRITE_EXISTING_FILE = 7;
  29         const FILETYPE_MISSING = 8;
  30         const FILETYPE_BADTYPE = 9;
  31         const VERIFICATION_ERROR = 10;
  32
  33         # HOOK_ABORTED is the new name of UPLOAD_VERIFICATION_ERROR
  34         const UPLOAD_VERIFICATION_ERROR = 11;
  35         const HOOK_ABORTED = 11;
  36         const FILE_TOO_LARGE = 12;
  37
  38         const SESSION_VERSION = 2;
  39         const SESSION_KEYNAME = 'wsUploadData';
  40
  41         static public function getSessionKeyname() {
  42                 return self::SESSION_KEYNAME;
  43         }
  44
  45         public function getVerificationErrorCode( $error ) {
  46                 $code_to_status = array(self::EMPTY_FILE => 'empty-file',
  47                                                                 self::FILE_TOO_LARGE => 'file-too-large',
  48                                                                 self::FILETYPE_MISSING => 'filetype-missing',
  49                                                                 self::FILETYPE_BADTYPE => 'filetype-banned',
  50                                                                 self::MIN_LENGTH_PARTNAME => 'filename-tooshort',
  51                                                                 self::ILLEGAL_FILENAME => 'illegal-filename',
  52                                                                 self::OVERWRITE_EXISTING_FILE => 'overwrite',
  53                                                                 self::VERIFICATION_ERROR => 'verification-error',
  54                                                                 self::HOOK_ABORTED =>  'hookaborted',
  55                 );
  56                 if( isset( $code_to_status[$error] ) ) {
  57                         return $code_to_status[$error];
  58                 }
  59
  60                 return 'unknown-error';
  61         }
  62
  63         /**
  64          * Returns true if uploads are enabled.
  65          * Can be override by subclasses.
  66          */
  67         public static function isEnabled() {
  68                 global $wgEnableUploads;
  69                 if ( !$wgEnableUploads ) {
  70                         return false;
  71                 }
  72
  73                 # Check php's file_uploads setting
  74                 if( !wfIniGetBool( 'file_uploads' ) ) {
  75                         return false;
  76                 }
  77                 return true;
  78         }
  79
  80         /**
  81          * Returns an array of permissions that is required to upload a file
  82          *
  83          * @return array
  84          */
  85         public static function getRequiredPermissions() {
  86                 return array( 'upload', 'create', 'edit' );
  87         }
  88         /**
  89          * Returns true if the user can use this upload module or else a string
  90          * identifying the missing permission.
  91          * Can be overriden by subclasses.
  92          */
  93         public static function isAllowed( $user ) {
  94                 foreach ( self::getRequiredPermissions as $permission ) {
  95                         if ( !$user->isAllowed( $permission ) ) {
  96                                 return $permission;
  97                         }
  98                 }
  99                 return true;
 100         }
 101
 102         // Upload handlers. Should probably just be a global.
 103         static $uploadHandlers = array( 'Stash', 'File', 'Url' );
 104
 105         /**
 106          * Create a form of UploadBase depending on wpSourceType and initializes it
 107          */
 108         public static function createFromRequest( &$request, $type = null ) {
 109                 $type = $type ? $type : $request->getVal( 'wpSourceType', 'File' );
 110
 111                 if( !$type ) {
 112                         return null;
 113                 }
 114
 115                 // Get the upload class
 116                 $type = ucfirst( $type );
 117
 118                 // Give hooks the chance to handle this request
 119                 $className = null;
 120                 wfRunHooks( 'UploadCreateFromRequest', array( $type, &$className ) );
 121                 if ( is_null( $className ) ) {
 122                         $className = 'UploadFrom' . $type;
 123                         wfDebug( __METHOD__ . ": class name: $className\n" );
 124                         if( !in_array( $type, self::$uploadHandlers ) ) {
 125                                 return null;
 126                         }
 127                 }
 128
 129                 // Check whether this upload class is enabled
 130                 if( !call_user_func( array( $className, 'isEnabled' ) ) ) {
 131                         return null;
 132                 }
 133
 134                 // Check whether the request is valid
 135                 if( !call_user_func( array( $className, 'isValidRequest' ), $request ) ) {
 136                         return null;
 137                 }
 138
 139                 $handler = new $className;
 140
 141                 $handler->initializeFromRequest( $request );
 142                 return $handler;
 143         }
 144
 145         /**
 146          * Check whether a request if valid for this handler
 147          */
 148         public static function isValidRequest( $request ) {
 149                 return false;
 150         }
 151
 152         public function __construct() {}
 153
 154         /**
 155          * Initialize the path information
 156          * @param $name string the desired destination name
 157          * @param $tempPath string the temporary path
 158          * @param $fileSize int the file size
 159          * @param $removeTempFile bool (false) remove the temporary file?
 160          * @return null
 161          */
 162         public function initializePathInfo( $name, $tempPath, $fileSize, $removeTempFile = false ) {
 163                 $this->mDesiredDestName = $name;
 164                 $this->mTempPath = $tempPath;
 165                 $this->mFileSize = $fileSize;
 166                 $this->mRemoveTempFile = $removeTempFile;
 167         }
 168
 169         /**
 170          * Initialize from a WebRequest. Override this in a subclass.
 171          */
 172         public abstract function initializeFromRequest( &$request );
 173
 174         /**
 175          * Fetch the file. Usually a no-op
 176          */
 177         public function fetchFile() {
 178                 return Status::newGood();
 179         }
 180
 181         /**
 182          * Return true if the file is empty
 183          * @return bool
 184          */
 185         public function isEmptyFile() {
 186                 return empty( $this->mFileSize );
 187         }
 188
 189         /**
 190          * Return the file size
 191          * @return integer
 192          */
 193         public function getFileSize() {
 194                 return $this->mFileSize;
 195         }
 196
 197         /**
 198          * Append a file to the Repo file
 199          *
 200          * @param $srcPath String: path to source file
 201          * @param $toAppendPath String: path to the Repo file that will be appended to.
 202          * @return Status Status
 203          */
 204         protected function appendToUploadFile( $srcPath, $toAppendPath ) {
 205                 $repo = RepoGroup::singleton()->getLocalRepo();
 206                 $status = $repo->append( $srcPath, $toAppendPath );
 207                 return $status;
 208         }
 209
 210         /**
 211          * @param $srcPath String: the source path
 212          * @return the real path if it was a virtual URL
 213          */
 214         function getRealPath( $srcPath ) {
 215                 $repo = RepoGroup::singleton()->getLocalRepo();
 216                 if ( $repo->isVirtualUrl( $srcPath ) ) {
 217                         return $repo->resolveVirtualUrl( $srcPath );
 218                 }
 219                 return $srcPath;
 220         }
 221
 222         /**
 223          * Verify whether the upload is sane.
 224          * @return mixed self::OK or else an array with error information
 225          */
 226         public function verifyUpload( ) {
 227                 /**
 228                  * If there was no filename or a zero size given, give up quick.
 229                  */
 230                 if( $this->isEmptyFile() ) {
 231                         return array( 'status' => self::EMPTY_FILE );
 232                 }
 233
 234                 /**
 235                  * Honor $wgMaxUploadSize
 236                  */
 237                 global $wgMaxUploadSize;
 238                 if( $this->mFileSize > $wgMaxUploadSize ) {
 239                         return array( 'status' => self::FILE_TOO_LARGE );
 240                 }
 241
 242                 /**
 243                  * Look at the contents of the file; if we can recognize the
 244                  * type but it's corrupt or data of the wrong type, we should
 245                  * probably not accept it.
 246                  */
 247                 $verification = $this->verifyFile();
 248                 if( $verification !== true ) {
 249                         return array(
 250                                 'status' => self::VERIFICATION_ERROR,
 251                                 'details' => $verification
 252                         );
 253                 }
 254
 255                 /**
 256                  * Make sure this file can be created
 257                  */
 258                 $result = $this->validateNameAndOverwrite();
 259                 if( $result !== true ) {
 260                         return $result;
 261                 }
 262
 263                 $error = '';
 264                 if( !wfRunHooks( 'UploadVerification',
 265                                 array( $this->mDestName, $this->mTempPath, &$error ) ) ) {
 266                         // @fixme This status needs another name...
 267                         return array( 'status' => self::HOOK_ABORTED, 'error' => $error );
 268                 }
 269
 270                 return array( 'status' => self::OK );
 271         }
 272
 273         /**
 274          * Verify that the name is valid and, if necessary, that we can overwrite
 275          *
 276          * @return mixed true if valid, otherwise and array with 'status'
 277          * and other keys
 278          **/
 279         public function validateNameAndOverwrite() {
 280                 $nt = $this->getTitle();
 281                 if( is_null( $nt ) ) {
 282                         $result = array( 'status' => $this->mTitleError );
 283                         if( $this->mTitleError == self::ILLEGAL_FILENAME ) {
 284                                 $result['filtered'] = $this->mFilteredName;
 285                         }
 286                         if ( $this->mTitleError == self::FILETYPE_BADTYPE ) {
 287                                 $result['finalExt'] = $this->mFinalExtension;
 288                         }
 289                         return $result;
 290                 }
 291                 $this->mDestName = $this->getLocalFile()->getName();
 292
 293                 /**
 294                  * In some cases we may forbid overwriting of existing files.
 295                  */
 296                 $overwrite = $this->checkOverwrite();
 297                 if( $overwrite !== true ) {
 298                         return array(
 299                                 'status' => self::OVERWRITE_EXISTING_FILE,
 300                                 'overwrite' => $overwrite
 301                         );
 302                 }
 303                 return true;
 304         }
 305
 306         /**
 307          * Verify the mime type
 308          * @param $magic MagicMime object
 309          * @param $mime string representing the mime
 310          * @return mixed true if the file is verified, an array otherwise
 311          */
 312         protected function verifyMimeType( $magic, $mime ) {
 313                 global $wgVerifyMimeType;
 314                 if ( $wgVerifyMimeType ) {
 315                         wfDebug ( "\n\nmime: <$mime> extension: <{$this->mFinalExtension}>\n\n");
 316                         if ( !$this->verifyExtension( $mime, $this->mFinalExtension ) ) {
 317                                 return array( 'filetype-mime-mismatch' );
 318                         }
 319
 320                         global $wgMimeTypeBlacklist;
 321                         if ( $this->checkFileExtension( $mime, $wgMimeTypeBlacklist ) ) {
 322                                 return array( 'filetype-badmime', $mime );
 323                         }
 324
 325                         # Check IE type
 326                         $fp = fopen( $this->mTempPath, 'rb' );
 327                         $chunk = fread( $fp, 256 );
 328                         fclose( $fp );
 329                         $extMime = $magic->guessTypesForExtension( $this->mFinalExtension );
 330                         $ieTypes = $magic->getIEMimeTypes( $this->mTempPath, $chunk, $extMime );
 331                         foreach ( $ieTypes as $ieType ) {
 332                                 if ( $this->checkFileExtension( $ieType, $wgMimeTypeBlacklist ) ) {
 333                                         return array( 'filetype-bad-ie-mime', $ieType );
 334                                 }
 335                         }
 336                 }
 337
 338                 return true;
 339         }
 340
 341         /**
 342          * Verifies that it's ok to include the uploaded file
 343          *
 344          * @return mixed true of the file is verified, array otherwise.
 345          */
 346         protected function verifyFile() {
 347                 $this->mFileProps = File::getPropsFromPath( $this->mTempPath, $this->mFinalExtension );
 348                 $this->checkMacBinary();
 349
 350                 # magically determine mime type
 351                 $magic = MimeMagic::singleton();
 352                 $mime = $magic->guessMimeType( $this->mTempPath, false );
 353
 354                 # check mime type, if desired
 355                 $status = $this->verifyMimeType( $magic, $mime );
 356                 if ( $status !== true ) {
 357                         return $status;
 358                 }
 359
 360                 # check for htmlish code and javascript
 361                 if( self::detectScript( $this->mTempPath, $mime, $this->mFinalExtension ) ) {
 362                         return array( 'uploadscripted' );
 363                 }
 364                 if( $this->mFinalExtension == 'svg' || $mime == 'image/svg+xml' ) {
 365                         if( self::detectScriptInSvg( $this->mTempPath ) ) {
 366                                 return array( 'uploadscripted' );
 367                         }
 368                 }
 369
 370                 /**
 371                 * Scan the uploaded file for viruses
 372                 */
 373                 $virus = $this->detectVirus( $this->mTempPath );
 374                 if ( $virus ) {
 375                         return array( 'uploadvirus', $virus );
 376                 }
 377                 wfDebug( __METHOD__ . ": all clear; passing.\n" );
 378                 return true;
 379         }
 380
 381         /**
 382          * Check whether the user can edit, upload and create the image.
 383          *
 384          * @param $user the User object to verify the permissions against
 385          * @return mixed An array as returned by getUserPermissionsErrors or true
 386          *               in case the user has proper permissions.
 387          */
 388         public function verifyPermissions( $user ) {
 389                 /**
 390                  * If the image is protected, non-sysop users won't be able
 391                  * to modify it by uploading a new revision.
 392                  */
 393                 $nt = $this->getTitle();
 394                 if( is_null( $nt ) ) {
 395                         return true;
 396                 }
 397                 $permErrors = $nt->getUserPermissionsErrors( 'edit', $user );
 398                 $permErrorsUpload = $nt->getUserPermissionsErrors( 'upload', $user );
 399                 $permErrorsCreate = ( $nt->exists() ? array() : $nt->getUserPermissionsErrors( 'create', $user ) );
 400                 if( $permErrors || $permErrorsUpload || $permErrorsCreate ) {
 401                         $permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsUpload, $permErrors ) );
 402                         $permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsCreate, $permErrors ) );
 403                         return $permErrors;
 404                 }
 405                 return true;
 406         }
 407
 408         /**
 409          * Check for non fatal problems with the file
 410          *
 411          * @return Array of warnings
 412          */
 413         public function checkWarnings() {
 414                 $warnings = array();
 415
 416                 $localFile = $this->getLocalFile();
 417                 $filename = $localFile->getName();
 418                 $n = strrpos( $filename, '.' );
 419                 $partname = $n ? substr( $filename, 0, $n ) : $filename;
 420
 421                 /**
 422                  * Check whether the resulting filename is different from the desired one,
 423                  * but ignore things like ucfirst() and spaces/underscore things
 424                  */
 425                 $comparableName = str_replace( ' ', '_', $this->mDesiredDestName );
 426                 $comparableName = Title::capitalize( $comparableName, NS_FILE );
 427
 428                 if( $this->mDesiredDestName != $filename && $comparableName != $filename ) {
 429                         $warnings['badfilename'] = $filename;
 430                 }
 431
 432                 // Check whether the file extension is on the unwanted list
 433                 global $wgCheckFileExtensions, $wgFileExtensions;
 434                 if ( $wgCheckFileExtensions ) {
 435                         if ( !$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) ) {
 436                                 $warnings['filetype-unwanted-type'] = $this->mFinalExtension;
 437                         }
 438                 }
 439
 440                 global $wgUploadSizeWarning;
 441                 if ( $wgUploadSizeWarning && ( $this->mFileSize > $wgUploadSizeWarning ) ) {
 442                         $warnings['large-file'] = $wgUploadSizeWarning;
 443                 }
 444
 445                 if ( $this->mFileSize == 0 ) {
 446                         $warnings['emptyfile'] = true;
 447                 }
 448
 449                 $exists = self::getExistsWarning( $localFile );
 450                 if( $exists !== false ) {
 451                         $warnings['exists'] = $exists;
 452                 }
 453
 454                 // Check dupes against existing files
 455                 $hash = File::sha1Base36( $this->mTempPath );
 456                 $dupes = RepoGroup::singleton()->findBySha1( $hash );
 457                 $title = $this->getTitle();
 458                 // Remove all matches against self
 459                 foreach ( $dupes as $key => $dupe ) {
 460                         if( $title->equals( $dupe->getTitle() ) ) {
 461                                 unset( $dupes[$key] );
 462                         }
 463                 }
 464                 if( $dupes ) {
 465                         $warnings['duplicate'] = $dupes;
 466                 }
 467
 468                 // Check dupes against archives
 469                 $archivedImage = new ArchivedFile( null, 0, "{$hash}.{$this->mFinalExtension}" );
 470                 if ( $archivedImage->getID() > 0 ) {
 471                         $warnings['duplicate-archive'] = $archivedImage->getName();
 472                 }
 473
 474                 return $warnings;
 475         }
 476
 477         /**
 478          * Really perform the upload. Stores the file in the local repo, watches
 479          * if necessary and runs the UploadComplete hook.
 480          *
 481          * @return mixed Status indicating the whether the upload succeeded.
 482          */
 483         public function performUpload( $comment, $pageText, $watch, $user ) {
 484                 wfDebug( "\n\n\performUpload: sum: " . $comment . ' c: ' . $pageText .
 485                         ' w: ' . $watch );
 486                 $status = $this->getLocalFile()->upload( $this->mTempPath, $comment, $pageText,
 487                         File::DELETE_SOURCE, $this->mFileProps, false, $user );
 488
 489                 if( $status->isGood() ) {
 490                         if ( $watch ) {
 491                                 $user->addWatch( $this->getLocalFile()->getTitle() );
 492                         }
 493
 494                         wfRunHooks( 'UploadComplete', array( &$this ) );
 495                 }
 496
 497                 return $status;
 498         }
 499
 500         /**
 501          * Returns the title of the file to be uploaded. Sets mTitleError in case
 502          * the name was illegal.
 503          *
 504          * @return Title The title of the file or null in case the name was illegal
 505          */
 506         public function getTitle() {
 507                 if ( $this->mTitle !== false ) {
 508                         return $this->mTitle;
 509                 }
 510
 511                 /**
 512                  * Chop off any directories in the given filename. Then
 513                  * filter out illegal characters, and try to make a legible name
 514                  * out of it. We'll strip some silently that Title would die on.
 515                  */
 516                 $this->mFilteredName = wfStripIllegalFilenameChars( $this->mDesiredDestName );
 517                 /* Normalize to title form before we do any further processing */
 518                 $nt = Title::makeTitleSafe( NS_FILE, $this->mFilteredName );
 519                 if( is_null( $nt ) ) {
 520                         $this->mTitleError = self::ILLEGAL_FILENAME;
 521                         return $this->mTitle = null;
 522                 }
 523                 $this->mFilteredName = $nt->getDBkey();
 524
 525                 /**
 526                  * We'll want to blacklist against *any* 'extension', and use
 527                  * only the final one for the whitelist.
 528                  */
 529                 list( $partname, $ext ) = $this->splitExtensions( $this->mFilteredName );
 530
 531                 if( count( $ext ) ) {
 532                         $this->mFinalExtension = trim( $ext[count( $ext ) - 1] );
 533                 } else {
 534                         $this->mFinalExtension = '';
 535                 }
 536
 537                 /* Don't allow users to override the blacklist (check file extension) */
 538                 global $wgCheckFileExtensions, $wgStrictFileExtensions;
 539                 global $wgFileExtensions, $wgFileBlacklist;
 540                 if ( $this->mFinalExtension == '' ) {
 541                         $this->mTitleError = self::FILETYPE_MISSING;
 542                         return $this->mTitle = null;
 543                 } elseif ( $this->checkFileExtensionList( $ext, $wgFileBlacklist ) ||
 544                                 ( $wgCheckFileExtensions && $wgStrictFileExtensions &&
 545                                         !$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) ) ) {
 546                         $this->mTitleError = self::FILETYPE_BADTYPE;
 547                         return $this->mTitle = null;
 548                 }
 549
 550                 # If there was more than one "extension", reassemble the base
 551                 # filename to prevent bogus complaints about length
 552                 if( count( $ext ) > 1 ) {
 553                         for( $i = 0; $i < count( $ext ) - 1; $i++ ) {
 554                                 $partname .= '.' . $ext[$i];
 555                         }
 556                 }
 557
 558                 if( strlen( $partname ) < 1 ) {
 559                         $this->mTitleError =  self::MIN_LENGTH_PARTNAME;
 560                         return $this->mTitle = null;
 561                 }
 562
 563                 return $this->mTitle = $nt;
 564         }
 565
 566         /**
 567          * Return the local file and initializes if necessary.
 568          */
 569         public function getLocalFile() {
 570                 if( is_null( $this->mLocalFile ) ) {
 571                         $nt = $this->getTitle();
 572                         $this->mLocalFile = is_null( $nt ) ? null : wfLocalFile( $nt );
 573                 }
 574                 return $this->mLocalFile;
 575         }
 576
 577         /**
 578          * Stash a file in a temporary directory for later processing
 579          * after the user has confirmed it.
 580          *
 581          * If the user doesn't explicitly cancel or accept, these files
 582          * can accumulate in the temp directory.
 583          *
 584          * @param $saveName String: the destination filename
 585          * @param $tempSrc String: the source temporary file to save
 586          * @return String: full path the stashed file, or false on failure
 587          */
 588         protected function saveTempUploadedFile( $saveName, $tempSrc ) {
 589                 $repo = RepoGroup::singleton()->getLocalRepo();
 590                 $status = $repo->storeTemp( $saveName, $tempSrc );
 591                 return $status;
 592         }
 593
 594         /**
 595          * Stash a file in a temporary directory for later processing,
 596          * and save the necessary descriptive info into the session.
 597          * Returns a key value which will be passed through a form
 598          * to pick up the path info on a later invocation.
 599          *
 600          * @return Integer: session key
 601          */
 602         public function stashSession() {
 603                 $status = $this->saveTempUploadedFile( $this->mDestName, $this->mTempPath );
 604                 if( !$status->isOK() ) {
 605                         # Couldn't save the file.
 606                         return false;
 607                 }
 608
 609                 $key = $this->getSessionKey();
 610                 $_SESSION[self::SESSION_KEYNAME][$key] = array(
 611                         'mTempPath'       => $status->value,
 612                         'mFileSize'       => $this->mFileSize,
 613                         'mFileProps'      => $this->mFileProps,
 614                         'version'         => self::SESSION_VERSION,
 615                 );
 616                 return $key;
 617         }
 618
 619         /**
 620          * Generate a random session key from stash in cases where we want
 621          * to start an upload without much information
 622          */
 623         protected function getSessionKey() {
 624                 $key = mt_rand( 0, 0x7fffffff );
 625                 $_SESSION[self::SESSION_KEYNAME][$key] = array();
 626                 return $key;
 627         }
 628
 629         /**
 630          * If we've modified the upload file we need to manually remove it
 631          * on exit to clean up.
 632          */
 633         public function cleanupTempFile() {
 634                 if ( $this->mRemoveTempFile && $this->mTempPath && file_exists( $this->mTempPath ) ) {
 635                         wfDebug( __METHOD__ . ": Removing temporary file {$this->mTempPath}\n" );
 636                         unlink( $this->mTempPath );
 637                 }
 638         }
 639
 640         public function getTempPath() {
 641                 return $this->mTempPath;
 642         }
 643
 644         /**
 645          * Split a file into a base name and all dot-delimited 'extensions'
 646          * on the end. Some web server configurations will fall back to
 647          * earlier pseudo-'extensions' to determine type and execute
 648          * scripts, so the blacklist needs to check them all.
 649          *
 650          * @return array
 651          */
 652         public static function splitExtensions( $filename ) {
 653                 $bits = explode( '.', $filename );
 654                 $basename = array_shift( $bits );
 655                 return array( $basename, $bits );
 656         }
 657
 658         /**
 659          * Perform case-insensitive match against a list of file extensions.
 660          * Returns true if the extension is in the list.
 661          *
 662          * @param $ext String
 663          * @param $list Array
 664          * @return Boolean
 665          */
 666         public static function checkFileExtension( $ext, $list ) {
 667                 return in_array( strtolower( $ext ), $list );
 668         }
 669
 670         /**
 671          * Perform case-insensitive match against a list of file extensions.
 672          * Returns true if any of the extensions are in the list.
 673          *
 674          * @param $ext Array
 675          * @param $list Array
 676          * @return Boolean
 677          */
 678         public static function checkFileExtensionList( $ext, $list ) {
 679                 foreach( $ext as $e ) {
 680                         if( in_array( strtolower( $e ), $list ) ) {
 681                                 return true;
 682                         }
 683                 }
 684                 return false;
 685         }
 686
 687         /**
 688          * Checks if the mime type of the uploaded file matches the file extension.
 689          *
 690          * @param $mime String: the mime type of the uploaded file
 691          * @param $extension String: the filename extension that the file is to be served with
 692          * @return Boolean
 693          */
 694         public static function verifyExtension( $mime, $extension ) {
 695                 $magic = MimeMagic::singleton();
 696
 697                 if ( !$mime || $mime == 'unknown' || $mime == 'unknown/unknown' )
 698                         if ( !$magic->isRecognizableExtension( $extension ) ) {
 699                                 wfDebug( __METHOD__ . ": passing file with unknown detected mime type; " .
 700                                         "unrecognized extension '$extension', can't verify\n" );
 701                                 return true;
 702                         } else {
 703                                 wfDebug( __METHOD__ . ": rejecting file with unknown detected mime type; ".
 704                                         "recognized extension '$extension', so probably invalid file\n" );
 705                                 return false;
 706                         }
 707
 708                 $match = $magic->isMatchingExtension( $extension, $mime );
 709
 710                 if ( $match === null ) {
 711                         wfDebug( __METHOD__ . ": no file extension known for mime type $mime, passing file\n" );
 712                         return true;
 713                 } elseif( $match === true ) {
 714                         wfDebug( __METHOD__ . ": mime type $mime matches extension $extension, passing file\n" );
 715
 716                         #TODO: if it's a bitmap, make sure PHP or ImageMagic resp. can handle it!
 717                         return true;
 718
 719                 } else {
 720                         wfDebug( __METHOD__ . ": mime type $mime mismatches file extension $extension, rejecting file\n" );
 721                         return false;
 722                 }
 723         }
 724
 725         /**
 726          * Heuristic for detecting files that *could* contain JavaScript instructions or
 727          * things that may look like HTML to a browser and are thus
 728          * potentially harmful. The present implementation will produce false
 729          * positives in some situations.
 730          *
 731          * @param $file String: pathname to the temporary upload file
 732          * @param $mime String: the mime type of the file
 733          * @param $extension String: the extension of the file
 734          * @return Boolean: true if the file contains something looking like embedded scripts
 735          */
 736         public static function detectScript( $file, $mime, $extension ) {
 737                 global $wgAllowTitlesInSVG;
 738
 739                 # ugly hack: for text files, always look at the entire file.
 740                 # For binary field, just check the first K.
 741
 742                 if( strpos( $mime,'text/' ) === 0 ) {
 743                         $chunk = file_get_contents( $file );
 744                 } else {
 745                         $fp = fopen( $file, 'rb' );
 746                         $chunk = fread( $fp, 1024 );
 747                         fclose( $fp );
 748                 }
 749
 750                 $chunk = strtolower( $chunk );
 751
 752                 if( !$chunk ) {
 753                         return false;
 754                 }
 755
 756                 # decode from UTF-16 if needed (could be used for obfuscation).
 757                 if( substr( $chunk, 0, 2 ) == "\xfe\xff" ) {
 758                         $enc = 'UTF-16BE';
 759                 } elseif( substr( $chunk, 0, 2 ) == "\xff\xfe" ) {
 760                         $enc = 'UTF-16LE';
 761                 } else {
 762                         $enc = null;
 763                 }
 764
 765                 if( $enc ) {
 766                         $chunk = iconv( $enc, "ASCII//IGNORE", $chunk );
 767                 }
 768
 769                 $chunk = trim( $chunk );
 770
 771                 # FIXME: convert from UTF-16 if necessarry!
 772                 wfDebug( __METHOD__ . ": checking for embedded scripts and HTML stuff\n" );
 773
 774                 # check for HTML doctype
 775                 if ( preg_match( "/<!DOCTYPE *X?HTML/i", $chunk ) ) {
 776                         return true;
 777                 }
 778
 779                 /**
 780                  * Internet Explorer for Windows performs some really stupid file type
 781                  * autodetection which can cause it to interpret valid image files as HTML
 782                  * and potentially execute JavaScript, creating a cross-site scripting
 783                  * attack vectors.
 784                  *
 785                  * Apple's Safari browser also performs some unsafe file type autodetection
 786                  * which can cause legitimate files to be interpreted as HTML if the
 787                  * web server is not correctly configured to send the right content-type
 788                  * (or if you're really uploading plain text and octet streams!)
 789                  *
 790                  * Returns true if IE is likely to mistake the given file for HTML.
 791                  * Also returns true if Safari would mistake the given file for HTML
 792                  * when served with a generic content-type.
 793                  */
 794                 $tags = array(
 795                         '<a href',
 796                         '<body',
 797                         '<head',
 798                         '<html',   #also in safari
 799                         '<img',
 800                         '<pre',
 801                         '<script', #also in safari
 802                         '<table'
 803                 );
 804
 805                 if( !$wgAllowTitlesInSVG && $extension !== 'svg' && $mime !== 'image/svg' ) {
 806                         $tags[] = '<title';
 807                 }
 808
 809                 foreach( $tags as $tag ) {
 810                         if( false !== strpos( $chunk, $tag ) ) {
 811                                 return true;
 812                         }
 813                 }
 814
 815                 /*
 816                  * look for JavaScript
 817                  */
 818
 819                 # resolve entity-refs to look at attributes. may be harsh on big files... cache result?
 820                 $chunk = Sanitizer::decodeCharReferences( $chunk );
 821
 822                 # look for script-types
 823                 if( preg_match( '!type\s*=\s*[\'"]?\s*(?:\w*/)?(?:ecma|java)!sim', $chunk ) ) {
 824                         return true;
 825                 }
 826
 827                 # look for html-style script-urls
 828                 if( preg_match( '!(?:href|src|data)\s*=\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
 829                         return true;
 830                 }
 831
 832                 # look for css-style script-urls
 833                 if( preg_match( '!url\s*\(\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
 834                         return true;
 835                 }
 836
 837                 wfDebug( __METHOD__ . ": no scripts found\n" );
 838                 return false;
 839         }
 840
 841         protected function detectScriptInSvg( $filename ) {
 842                 $check = new XmlTypeCheck( $filename, array( $this, 'checkSvgScriptCallback' ) );
 843                 return $check->filterMatch;
 844         }
 845
 846         /**
 847          * @todo Replace this with a whitelist filter!
 848          */
 849         public function checkSvgScriptCallback( $element, $attribs ) {
 850                 $stripped = $this->stripXmlNamespace( $element );
 851
 852                 if( $stripped == 'script' ) {
 853                         wfDebug( __METHOD__ . ": Found script element '$element' in uploaded file.\n" );
 854                         return true;
 855                 }
 856
 857                 foreach( $attribs as $attrib => $value ) {
 858                         $stripped = $this->stripXmlNamespace( $attrib );
 859                         if( substr( $stripped, 0, 2 ) == 'on' ) {
 860                                 wfDebug( __METHOD__ . ": Found script attribute '$attrib'='value' in uploaded file.\n" );
 861                                 return true;
 862                         }
 863                         if( $stripped == 'href' && strpos( strtolower( $value ), 'javascript:' ) !== false ) {
 864                                 wfDebug( __METHOD__ . ": Found script href attribute '$attrib'='$value' in uploaded file.\n" );
 865                                 return true;
 866                         }
 867                 }
 868         }
 869
 870         private function stripXmlNamespace( $name ) {
 871                 // 'http://www.w3.org/2000/svg:script' -> 'script'
 872                 $parts = explode( ':', strtolower( $name ) );
 873                 return array_pop( $parts );
 874         }
 875
 876         /**
 877          * Generic wrapper function for a virus scanner program.
 878          * This relies on the $wgAntivirus and $wgAntivirusSetup variables.
 879          * $wgAntivirusRequired may be used to deny upload if the scan fails.
 880          *
 881          * @param $file String: pathname to the temporary upload file
 882          * @return mixed false if not virus is found, NULL if the scan fails or is disabled,
 883          *         or a string containing feedback from the virus scanner if a virus was found.
 884          *         If textual feedback is missing but a virus was found, this function returns true.
 885          */
 886         public static function detectVirus( $file ) {
 887                 global $wgAntivirus, $wgAntivirusSetup, $wgAntivirusRequired, $wgOut;
 888
 889                 if ( !$wgAntivirus ) {
 890                         wfDebug( __METHOD__ . ": virus scanner disabled\n" );
 891                         return null;
 892                 }
 893
 894                 if ( !$wgAntivirusSetup[$wgAntivirus] ) {
 895                         wfDebug( __METHOD__ . ": unknown virus scanner: $wgAntivirus\n" );
 896                         $wgOut->wrapWikiMsg( "<div class=\"error\">\n$1</div>",
 897                                 array( 'virus-badscanner', $wgAntivirus ) );
 898                         return wfMsg( 'virus-unknownscanner' ) . " $wgAntivirus";
 899                 }
 900
 901                 # look up scanner configuration
 902                 $command = $wgAntivirusSetup[$wgAntivirus]['command'];
 903                 $exitCodeMap = $wgAntivirusSetup[$wgAntivirus]['codemap'];
 904                 $msgPattern = isset( $wgAntivirusSetup[$wgAntivirus]['messagepattern'] ) ?
 905                         $wgAntivirusSetup[$wgAntivirus]['messagepattern'] : null;
 906
 907                 if ( strpos( $command, "%f" ) === false ) {
 908                         # simple pattern: append file to scan
 909                         $command .= " " . wfEscapeShellArg( $file );
 910                 } else {
 911                         # complex pattern: replace "%f" with file to scan
 912                         $command = str_replace( "%f", wfEscapeShellArg( $file ), $command );
 913                 }
 914
 915                 wfDebug( __METHOD__ . ": running virus scan: $command \n" );
 916
 917                 # execute virus scanner
 918                 $exitCode = false;
 919
 920                 # NOTE: there's a 50 line workaround to make stderr redirection work on windows, too.
 921                 #      that does not seem to be worth the pain.
 922                 #      Ask me (Duesentrieb) about it if it's ever needed.
 923                 $output = wfShellExec( "$command 2>&1", $exitCode );
 924
 925                 # map exit code to AV_xxx constants.
 926                 $mappedCode = $exitCode;
 927                 if ( $exitCodeMap ) {
 928                         if ( isset( $exitCodeMap[$exitCode] ) ) {
 929                                 $mappedCode = $exitCodeMap[$exitCode];
 930                         } elseif ( isset( $exitCodeMap["*"] ) ) {
 931                                 $mappedCode = $exitCodeMap["*"];
 932                         }
 933                 }
 934
 935                 if ( $mappedCode === AV_SCAN_FAILED ) {
 936                         # scan failed (code was mapped to false by $exitCodeMap)
 937                         wfDebug( __METHOD__ . ": failed to scan $file (code $exitCode).\n" );
 938
 939                         if ( $wgAntivirusRequired ) {
 940                                 return wfMsg( 'virus-scanfailed', array( $exitCode ) );
 941                         } else {
 942                                 return null;
 943                         }
 944                 } elseif ( $mappedCode === AV_SCAN_ABORTED ) {
 945                         # scan failed because filetype is unknown (probably imune)
 946                         wfDebug( __METHOD__ . ": unsupported file type $file (code $exitCode).\n" );
 947                         return null;
 948                 } elseif ( $mappedCode === AV_NO_VIRUS ) {
 949                         # no virus found
 950                         wfDebug( __METHOD__ . ": file passed virus scan.\n" );
 951                         return false;
 952                 } else {
 953                         $output = trim( $output );
 954
 955                         if ( !$output ) {
 956                                 $output = true; #if there's no output, return true
 957                         } elseif ( $msgPattern ) {
 958                                 $groups = array();
 959                                 if ( preg_match( $msgPattern, $output, $groups ) ) {
 960                                         if ( $groups[1] ) {
 961                                                 $output = $groups[1];
 962                                         }
 963                                 }
 964                         }
 965
 966                         wfDebug( __METHOD__ . ": FOUND VIRUS! scanner feedback: $output \n" );
 967                         return $output;
 968                 }
 969         }
 970
 971         /**
 972          * Check if the temporary file is MacBinary-encoded, as some uploads
 973          * from Internet Explorer on Mac OS Classic and Mac OS X will be.
 974          * If so, the data fork will be extracted to a second temporary file,
 975          * which will then be checked for validity and either kept or discarded.
 976          */
 977         private function checkMacBinary() {
 978                 $macbin = new MacBinary( $this->mTempPath );
 979                 if( $macbin->isValid() ) {
 980                         $dataFile = tempnam( wfTempDir(), 'WikiMacBinary' );
 981                         $dataHandle = fopen( $dataFile, 'wb' );
 982
 983                         wfDebug( __METHOD__ . ": Extracting MacBinary data fork to $dataFile\n" );
 984                         $macbin->extractData( $dataHandle );
 985
 986                         $this->mTempPath = $dataFile;
 987                         $this->mFileSize = $macbin->dataForkLength();
 988
 989                         // We'll have to manually remove the new file if it's not kept.
 990                         $this->mRemoveTempFile = true;
 991                 }
 992                 $macbin->close();
 993         }
 994
 995         /**
 996          * Check if there's an overwrite conflict and, if so, if restrictions
 997          * forbid this user from performing the upload.
 998          *
 999          * @return mixed true on success, error string on failure
1000          */
1001         private function checkOverwrite() {
1002                 global $wgUser;
1003                 // First check whether the local file can be overwritten
1004                 $file = $this->getLocalFile();
1005                 if( $file->exists() ) {
1006                         if( !self::userCanReUpload( $wgUser, $file ) ) {
1007                                 return 'fileexists-forbidden';
1008                         } else {
1009                                 return true;
1010                         }
1011                 }
1012
1013                 /* Check shared conflicts: if the local file does not exist, but
1014                  * wfFindFile finds a file, it exists in a shared repository.
1015                  */
1016                 $file = wfFindFile( $this->getTitle() );
1017                 if ( $file && !$wgUser->isAllowed( 'reupload-shared' ) ) {
1018                         return 'fileexists-shared-forbidden';
1019                 }
1020
1021                 return true;
1022         }
1023
1024         /**
1025          * Check if a user is the last uploader
1026          *
1027          * @param $user User object
1028          * @param $img String: image name
1029          * @return Boolean
1030          */
1031         public static function userCanReUpload( User $user, $img ) {
1032                 if( $user->isAllowed( 'reupload' ) ) {
1033                         return true; // non-conditional
1034                 }
1035                 if( !$user->isAllowed( 'reupload-own' ) ) {
1036                         return false;
1037                 }
1038                 if( is_string( $img ) ) {
1039                         $img = wfLocalFile( $img );
1040                 }
1041                 if ( !( $img instanceof LocalFile ) ) {
1042                         return false;
1043                 }
1044
1045                 return $user->getId() == $img->getUser( 'id' );
1046         }
1047
1048         /**
1049          * Helper function that does various existence checks for a file.
1050          * The following checks are performed:
1051          * - The file exists
1052          * - Article with the same name as the file exists
1053          * - File exists with normalized extension
1054          * - The file looks like a thumbnail and the original exists
1055          *
1056          * @param $file The File object to check
1057          * @return mixed False if the file does not exists, else an array
1058          */
1059         public static function getExistsWarning( $file ) {
1060                 if( $file->exists() ) {
1061                         return array( 'warning' => 'exists', 'file' => $file );
1062                 }
1063
1064                 if( $file->getTitle()->getArticleID() ) {
1065                         return array( 'warning' => 'page-exists', 'file' => $file );
1066                 }
1067
1068                 if ( $file->wasDeleted() && !$file->exists() ) {
1069                         return array( 'warning' => 'was-deleted', 'file' => $file );
1070                 }
1071
1072                 if( strpos( $file->getName(), '.' ) == false ) {
1073                         $partname = $file->getName();
1074                         $extension = '';
1075                 } else {
1076                         $n = strrpos( $file->getName(), '.' );
1077                         $extension = substr( $file->getName(), $n + 1 );
1078                         $partname = substr( $file->getName(), 0, $n );
1079                 }
1080                 $normalizedExtension = File::normalizeExtension( $extension );
1081
1082                 if ( $normalizedExtension != $extension ) {
1083                         // We're not using the normalized form of the extension.
1084                         // Normal form is lowercase, using most common of alternate
1085                         // extensions (eg 'jpg' rather than 'JPEG').
1086                         //
1087                         // Check for another file using the normalized form...
1088                         $nt_lc = Title::makeTitle( NS_FILE, "{$partname}.{$normalizedExtension}" );
1089                         $file_lc = wfLocalFile( $nt_lc );
1090
1091                         if( $file_lc->exists() ) {
1092                                 return array(
1093                                         'warning' => 'exists-normalized',
1094                                         'file' => $file,
1095                                         'normalizedFile' => $file_lc
1096                                 );
1097                         }
1098                 }
1099
1100                 if ( self::isThumbName( $file->getName() ) ) {
1101                         # Check for filenames like 50px- or 180px-, these are mostly thumbnails
1102                         $nt_thb = Title::newFromText( substr( $partname , strpos( $partname , '-' ) +1 ) . '.' . $extension, NS_FILE );
1103                         $file_thb = wfLocalFile( $nt_thb );
1104                         if( $file_thb->exists() ) {
1105                                 return array(
1106                                         'warning' => 'thumb',
1107                                         'file' => $file,
1108                                         'thumbFile' => $file_thb
1109                                 );
1110                         } else {
1111                                 // File does not exist, but we just don't like the name
1112                                 return array(
1113                                         'warning' => 'thumb-name',
1114                                         'file' => $file,
1115                                         'thumbFile' => $file_thb
1116                                 );
1117                         }
1118                 }
1119
1120
1121                 foreach( self::getFilenamePrefixBlacklist() as $prefix ) {
1122                         if ( substr( $partname, 0, strlen( $prefix ) ) == $prefix ) {
1123                                 return array(
1124                                         'warning' => 'bad-prefix',
1125                                         'file' => $file,
1126                                         'prefix' => $prefix
1127                                 );
1128                         }
1129                 }
1130
1131                 return false;
1132         }
1133
1134         /**
1135          * Helper function that checks whether the filename looks like a thumbnail
1136          */
1137         public static function isThumbName( $filename ) {
1138                 $n = strrpos( $filename, '.' );
1139                 $partname = $n ? substr( $filename, 0, $n ) : $filename;
1140                 return (
1141                                         substr( $partname , 3, 3 ) == 'px-' ||
1142                                         substr( $partname , 2, 3 ) == 'px-'
1143                                 ) &&
1144                                 preg_match( "/[0-9]{2}/" , substr( $partname , 0, 2 ) );
1145         }
1146
1147         /**
1148          * Get a list of blacklisted filename prefixes from [[MediaWiki:Filename-prefix-blacklist]]
1149          *
1150          * @return array list of prefixes
1151          */
1152         public static function getFilenamePrefixBlacklist() {
1153                 $blacklist = array();
1154                 $message = wfMsgForContent( 'filename-prefix-blacklist' );
1155                 if( $message && !( wfEmptyMsg( 'filename-prefix-blacklist', $message ) || $message == '-' ) ) {
1156                         $lines = explode( "\n", $message );
1157                         foreach( $lines as $line ) {
1158                                 // Remove comment lines
1159                                 $comment = substr( trim( $line ), 0, 1 );
1160                                 if ( $comment == '#' || $comment == '' ) {
1161                                         continue;
1162                                 }
1163                                 // Remove additional comments after a prefix
1164                                 $comment = strpos( $line, '#' );
1165                                 if ( $comment > 0 ) {
1166                                         $line = substr( $line, 0, $comment-1 );
1167                                 }
1168                                 $blacklist[] = trim( $line );
1169                         }
1170                 }
1171                 return $blacklist;
1172         }
1173
1174         public function getImageInfo( $result ) {
1175                 $file = $this->getLocalFile();
1176                 $imParam = ApiQueryImageInfo::getPropertyNames();
1177                 return ApiQueryImageInfo::getInfo( $file, array_flip( $imParam ), $result );
1178         }
1179
1180         public function convertVerifyErrorToStatus( $error ) {
1181                 $args = func_get_args();
1182                 array_shift($args);
1183                 return Status::newFatal( $this->getVerificationErrorCode( $error ), $args );
1184         }
1185 }