includes/UploadBase.php

   1 <?php
   2
   3 class UploadBase {
   4         var $mTempPath;
   5         var $mDesiredDestName, $mDestName, $mRemoveTempFile, $mSourceType;
   6         var $mTitle = false, $mTitleError = 0;
   7         var $mFilteredName, $mFinalExtension;
   8
   9         const SUCCESS = 0;
  10         const OK = 0;
  11         const BEFORE_PROCESSING = 1;
  12         const LARGE_FILE_SERVER = 2;
  13         const EMPTY_FILE = 3;
  14         const MIN_LENGTH_PARTNAME = 4;
  15         const ILLEGAL_FILENAME = 5;
  16         const PROTECTED_PAGE = 6;
  17         const OVERWRITE_EXISTING_FILE = 7;
  18         const FILETYPE_MISSING = 8;
  19         const FILETYPE_BADTYPE = 9;
  20         const VERIFICATION_ERROR = 10;
  21         const UPLOAD_VERIFICATION_ERROR = 11;
  22         const UPLOAD_WARNING = 12;
  23         const INTERNAL_ERROR = 13;
  24
  25         const SESSION_VERSION = 2;
  26
  27         /*
  28          * Returns true if uploads are enabled.
  29          * Can be overriden by subclasses.
  30          */
  31         static function isEnabled() {
  32                 global $wgEnableUploads;
  33                 return $wgEnableUploads;
  34         }
  35         /*
  36          * Returns true if the user can use this upload module or else a string
  37          * identifying the missing permission.
  38          * Can be overriden by subclasses.
  39          */
  40         static function isAllowed( $user ) {
  41                 if( !$user->isAllowed( 'upload' ) )
  42                         return 'upload';
  43                 return true;
  44         }
  45
  46         static $uploadHandlers = array( 'Stash', 'Upload', 'Url' );
  47         static function createFromRequest( &$request, $type = null ) {
  48                 $type = $type ? $type : $request->getVal( 'wpSourceType' );
  49                 if( !$type )
  50                         return null;
  51                 $type = ucfirst($type);
  52                 $className = 'UploadFrom'.$type;
  53                 if( !in_array( $type, self::$uploadHandlers ) )
  54                         return null;
  55                 if( !call_user_func( array( $className, 'isEnabled' ) ) )
  56                         return null;
  57                 if( !call_user_func( array( $className, 'isValidRequest' ), $request ) )
  58                         return null;
  59
  60                 $handler = new $className;
  61                 $handler->initializeFromRequest( $request );
  62                 return $handler;
  63         }
  64
  65         static function isValidRequest( $request ) {
  66                 return false;
  67         }
  68
  69         function __construct() {}
  70
  71         function initialize( $name, $tempPath, $fileSize, $removeTempFile = false ) {
  72                 $this->mDesiredDestName = $name;
  73                 $this->mTempPath = $tempPath;
  74                 $this->mFileSize = $fileSize;
  75                 $this->mRemoveTempFile = $removeTempFile;
  76         }
  77
  78         function verifyUpload() {
  79                 global $wgUser;
  80
  81                 /**
  82                  * If there was no filename or a zero size given, give up quick.
  83                  */
  84                 if( empty( $this->mFileSize ) )
  85                         return array( 'status' => self::EMPTY_FILE );
  86
  87                 $nt = $this->getTitle();
  88                 if( is_null( $nt ) ) {
  89                         $result = array( 'status' => $this->mTitleError );
  90                         if( $this->mTitleError == self::ILLEGAL_FILENAME )
  91                                 $resul['filtered'] = $this->mFilteredName;
  92                         if ( $this->mTitleError == self::FILETYPE_BADTYPE )
  93                                 $result['finalExt'] = $this->mFinalExtension;
  94                         return $result;
  95                 }
  96                 $this->mLocalFile = wfLocalFile( $nt );
  97                 $this->mDestName = $this->mLocalFile->getName();
  98
  99                 /**
 100                  * In some cases we may forbid overwriting of existing files.
 101                  */
 102                 $overwrite = $this->checkOverwrite( $this->mDestName );
 103                 if( $overwrite !== true )
 104                         return array( 'status' => self::OVERWRITE_EXISTING_FILE, 'overwrite' => $overwrite );
 105
 106                 /**
 107                  * Look at the contents of the file; if we can recognize the
 108                  * type but it's corrupt or data of the wrong type, we should
 109                  * probably not accept it.
 110                  */
 111                 $verification = $this->verifyFile( $this->mTempPath );
 112
 113                 if( $verification !== true ) {
 114                         if( !is_array( $verification ) )
 115                                 $verification = array( $verification );
 116                         $verification['status'] = self::VERIFICATION_ERROR;
 117                         return $verification;
 118                 }
 119
 120                 $error = '';
 121                 if( !wfRunHooks( 'UploadVerification',
 122                                 array( $this->mDestName, $this->mTempPath, &$error ) ) ) {
 123                         return array( 'status' => self::UPLOAD_VERIFICATION_ERROR, 'error' => $error );
 124                 }
 125
 126                 return self::OK;
 127         }
 128
 129         /**
 130          * Verifies that it's ok to include the uploaded file
 131          *
 132          * @param string $tmpfile the full path of the temporary file to verify
 133          * @return mixed true of the file is verified, a string or array otherwise.
 134          */
 135         protected function verifyFile( $tmpfile ) {
 136                 $this->mFileProps = File::getPropsFromPath( $this->mTempPath,
 137                 $this->mFinalExtension );
 138                 $this->checkMacBinary();
 139
 140                 #magically determine mime type
 141                 $magic = MimeMagic::singleton();
 142                 $mime = $magic->guessMimeType( $tmpfile, false );
 143
 144                 #check mime type, if desired
 145                 global $wgVerifyMimeType;
 146                 if ( $wgVerifyMimeType ) {
 147
 148                   wfDebug ( "\n\nmime: <$mime> extension: <{$this->mFinalExtension}>\n\n");
 149                         #check mime type against file extension
 150                         if( !self::verifyExtension( $mime, $this->mFinalExtension ) ) {
 151                                 return 'uploadcorrupt';
 152                         }
 153
 154                         #check mime type blacklist
 155                         global $wgMimeTypeBlacklist;
 156                         if( isset($wgMimeTypeBlacklist) && !is_null($wgMimeTypeBlacklist)
 157                                 && $this->checkFileExtension( $mime, $wgMimeTypeBlacklist ) ) {
 158                                 return array( 'filetype-badmime', $mime );
 159                         }
 160                 }
 161
 162                 #check for htmlish code and javascript
 163                 if( $this->detectScript ( $tmpfile, $mime, $this->mFinalExtension ) ) {
 164                         return 'uploadscripted';
 165                 }
 166
 167                 /**
 168                 * Scan the uploaded file for viruses
 169                 */
 170                 $virus = $this->detectVirus($tmpfile);
 171                 if ( $virus ) {
 172                         return array( 'uploadvirus', $virus );
 173                 }
 174
 175                 wfDebug( __METHOD__.": all clear; passing.\n" );
 176                 return true;
 177         }
 178
 179         function verifyPermissions( $user ) {
 180                 /**
 181                  * If the image is protected, non-sysop users won't be able
 182                  * to modify it by uploading a new revision.
 183                  */
 184                 $nt = $this->getTitle();
 185                 if( is_null( $nt ) )
 186                         return true;
 187                 $permErrors = $nt->getUserPermissionsErrors( 'edit', $user );
 188                 $permErrorsUpload = $nt->getUserPermissionsErrors( 'upload', $user );
 189                 $permErrorsCreate = ( $nt->exists() ? array() : $nt->getUserPermissionsErrors( 'create', $user ) );
 190                 if( $permErrors || $permErrorsUpload || $permErrorsCreate ) {
 191                         $permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsUpload, $permErrors ) );
 192                         $permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsCreate, $permErrors ) );
 193                         return $permErrors;
 194                 }
 195                 return true;
 196         }
 197
 198         function checkWarnings() {
 199                 $warning = array();
 200
 201                 $filename = $this->mLocalFile->getName();
 202                 $n = strrpos( $filename, '.' );
 203                 $partname = $n ? substr( $filename, 0, $n ) : $filename;
 204
 205                 global $wgCapitalLinks;
 206                 if( $this->mDesiredDestName != $filename )
 207                         $warning['badfilename'] = $filename;
 208
 209                 global $wgCheckFileExtensions, $wgFileExtensions;
 210                 if ( $wgCheckFileExtensions ) {
 211                         if ( !$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) )
 212                                 $warning['filetype-unwanted-type'] = $this->mFinalExtension;
 213                 }
 214
 215                 global $wgUploadSizeWarning;
 216                 if ( $wgUploadSizeWarning && ( $this->mFileSize > $wgUploadSizeWarning ) )
 217                         $warning['large-file'] = $wgUploadSizeWarning;
 218
 219                 if ( $this->mFileSize == 0 )
 220                         $warning['emptyfile'] = true;
 221
 222                 $exists = self::getExistsWarning( $this->mLocalFile );
 223                 if( $exists !== false )
 224                         $warning['exists'] = $exists;
 225
 226
 227                 if( $exists !== false && $exists[0] != 'thumb'
 228                                 && self::isThumbName( $this->mLocalFile->getName() ) )
 229                         $warning['file-thumbnail-no'] = substr( $filename , 0,
 230                                 strpos( $nt->getText() , '-' ) +1 );
 231
 232                 $hash = File::sha1Base36( $this->mTempPath );
 233                 $dupes = RepoGroup::singleton()->findBySha1( $hash );
 234                 if( $dupes )
 235                         $warning['duplicate'] = $dupes;
 236
 237                 $filenamePrefixBlacklist = self::getFilenamePrefixBlacklist();
 238                 foreach( $filenamePrefixBlacklist as $prefix ) {
 239                         if ( substr( $partname, 0, strlen( $prefix ) ) == $prefix ) {
 240                                 $warning['filename-bad-prefix'] = $prefix;
 241                                 break;
 242                         }
 243                 }
 244
 245                 # If the file existed before and was deleted, warn the user of this
 246                 # Don't bother doing so if the file exists now, however
 247                 if( $this->mLocalFile->wasDeleted() && !$this->mLocalFile->exists() )
 248                         $warning['filewasdeleted'] = $this->mLocalFile->getTitle();
 249
 250                 return $warning;
 251         }
 252
 253         function performUpload( $comment, $pageText, $watch, $user ) {
 254                 $status = $this->mLocalFile->upload( $this->mTempPath, $comment, $pageText,
 255                         File::DELETE_SOURCE, $this->mFileProps, false, $user );
 256
 257                 if( $status->isGood() && $watch ) {
 258                         $user->addWatch( $this->mLocalFile->getTitle() );
 259                 }
 260
 261                 if( $status->isGood() )
 262                         wfRunHooks( 'UploadComplete', array( &$this ) );
 263
 264                 return $status;
 265         }
 266
 267         /**
 268          * Returns a title or null
 269          */
 270         function getTitle() {
 271                 if ( $this->mTitle !== false )
 272                         return $this->mTitle;
 273
 274                 /**
 275                  * Chop off any directories in the given filename. Then
 276                  * filter out illegal characters, and try to make a legible name
 277                  * out of it. We'll strip some silently that Title would die on.
 278                  */
 279
 280                 $basename = $this->mDesiredDestName;
 281
 282                 $this->mFilteredName = wfStripIllegalFilenameChars( $basename );
 283
 284                 /**
 285                  * We'll want to blacklist against *any* 'extension', and use
 286                  * only the final one for the whitelist.
 287                  */
 288                 list( $partname, $ext ) = $this->splitExtensions( $this->mFilteredName );
 289
 290                 if( count( $ext ) ) {
 291                         $this->mFinalExtension = $ext[count( $ext ) - 1];
 292                 } else {
 293                         $this->mFinalExtension = '';
 294                 }
 295
 296                 /* Don't allow users to override the blacklist (check file extension) */
 297                 global $wgCheckFileExtensions, $wgStrictFileExtensions;
 298                 global $wgFileExtensions, $wgFileBlacklist;
 299                 if ( $this->mFinalExtension == '' ) {
 300                         $this->mTitleError = self::FILETYPE_MISSING;
 301                         return $this->mTitle = null;
 302                 } elseif ( $this->checkFileExtensionList( $ext, $wgFileBlacklist ) ||
 303                                 ( $wgCheckFileExtensions && $wgStrictFileExtensions &&
 304                                         !$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) ) ) {
 305                         $this->mTitleError = self::FILETYPE_BADTYPE;
 306                         return $this->mTitle = null;
 307                 }
 308
 309                 # If there was more than one "extension", reassemble the base
 310                 # filename to prevent bogus complaints about length
 311                 if( count( $ext ) > 1 ) {
 312                         for( $i = 0; $i < count( $ext ) - 1; $i++ )
 313                                 $partname .= '.' . $ext[$i];
 314                 }
 315
 316                 if( strlen( $partname ) < 1 ) {
 317                         $this->mTitleError =  self::MIN_LENGTH_PARTNAME;
 318                         return $this->mTitle = null;
 319                 }
 320
 321                 $nt = Title::makeTitleSafe( NS_IMAGE, $this->mFilteredName );
 322                 if( is_null( $nt ) ) {
 323                         $this->mTitleError = self::ILLEGAL_FILENAME;
 324                         return $this->mTitle = null;
 325                 }
 326                 return $this->mTitle = $nt;
 327         }
 328
 329         function getLocalFile() {
 330                 if( is_null( $this->mLocalFile ) ) {
 331                         $nt = $this->getTitle();
 332                         $this->mLocalFile = is_null( $nt ) ? null : wfLocalFile( $nt );
 333                 }
 334                 return $this->mLocalFile;
 335         }
 336
 337         /**
 338          * Stash a file in a temporary directory for later processing
 339          * after the user has confirmed it.
 340          *
 341          * If the user doesn't explicitly cancel or accept, these files
 342          * can accumulate in the temp directory.
 343          *
 344          * @param string $saveName - the destination filename
 345          * @param string $tempName - the source temporary file to save
 346          * @return string - full path the stashed file, or false on failure
 347          * @access private
 348          */
 349         function saveTempUploadedFile( $saveName, $tempName ) {
 350                 global $wgOut;
 351                 $repo = RepoGroup::singleton()->getLocalRepo();
 352                 $status = $repo->storeTemp( $saveName, $tempName );
 353                 return $status;
 354         }
 355
 356         /**
 357          * Stash a file in a temporary directory for later processing,
 358          * and save the necessary descriptive info into the session.
 359          * Returns a key value which will be passed through a form
 360          * to pick up the path info on a later invocation.
 361          *
 362          * @return int
 363          * @access private
 364          */
 365         function stashSession() {
 366                 $status = $this->saveTempUploadedFile( $this->mDestName, $this->mTempPath );
 367
 368                 if( !$status->isGood() ) {
 369                         # Couldn't save the file.
 370                         return false;
 371                 }
 372
 373                 return array(
 374                         'mTempPath'       => $status->value,
 375                         'mFileSize'       => $this->mFileSize,
 376                         'mFileProps'      => $this->mFileProps,
 377                         'version'         => self::SESSION_VERSION,
 378                 );
 379         }
 380
 381         /**
 382          * Remove a temporarily kept file stashed by saveTempUploadedFile().
 383          * @return success
 384          */
 385         function unsaveUploadedFile() {
 386                 $repo = RepoGroup::singleton()->getLocalRepo();
 387                 $success = $repo->freeTemp( $this->mTempPath );
 388                 return $success;
 389         }
 390
 391         /**
 392          * If we've modified the upload file we need to manually remove it
 393          * on exit to clean up.
 394          * @access private
 395          */
 396         function cleanupTempFile() {
 397                 if ( $this->mRemoveTempFile && file_exists( $this->mTempPath ) ) {
 398                         wfDebug( __METHOD__.": Removing temporary file {$this->mTempPath}\n" );
 399                         unlink( $this->mTempPath );
 400                 }
 401         }
 402
 403         function getTempPath() {
 404                 return $this->mTempPath;
 405         }
 406
 407
 408                 /**
 409          * Split a file into a base name and all dot-delimited 'extensions'
 410          * on the end. Some web server configurations will fall back to
 411          * earlier pseudo-'extensions' to determine type and execute
 412          * scripts, so the blacklist needs to check them all.
 413          *
 414          * @return array
 415          */
 416         function splitExtensions( $filename ) {
 417                 $bits = explode( '.', $filename );
 418                 $basename = array_shift( $bits );
 419                 return array( $basename, $bits );
 420         }
 421
 422         /**
 423          * Perform case-insensitive match against a list of file extensions.
 424          * Returns true if the extension is in the list.
 425          *
 426          * @param string $ext
 427          * @param array $list
 428          * @return bool
 429          */
 430         function checkFileExtension( $ext, $list ) {
 431                 return in_array( strtolower( $ext ), $list );
 432         }
 433
 434         /**
 435          * Perform case-insensitive match against a list of file extensions.
 436          * Returns true if any of the extensions are in the list.
 437          *
 438          * @param array $ext
 439          * @param array $list
 440          * @return bool
 441          */
 442         function checkFileExtensionList( $ext, $list ) {
 443                 foreach( $ext as $e ) {
 444                         if( in_array( strtolower( $e ), $list ) ) {
 445                                 return true;
 446                         }
 447                 }
 448                 return false;
 449         }
 450
 451
 452         /**
 453          * Checks if the mime type of the uploaded file matches the file extension.
 454          *
 455          * @param string $mime the mime type of the uploaded file
 456          * @param string $extension The filename extension that the file is to be served with
 457          * @return bool
 458          */
 459         public static function verifyExtension( $mime, $extension ) {
 460                 $magic = MimeMagic::singleton();
 461
 462                 if ( ! $mime || $mime == 'unknown' || $mime == 'unknown/unknown' )
 463                         if ( ! $magic->isRecognizableExtension( $extension ) ) {
 464                                 wfDebug( __METHOD__.": passing file with unknown detected mime type; " .
 465                                         "unrecognized extension '$extension', can't verify\n" );
 466                                 return true;
 467                         } else {
 468                                 wfDebug( __METHOD__.": rejecting file with unknown detected mime type; ".
 469                                         "recognized extension '$extension', so probably invalid file\n" );
 470                                 return false;
 471                         }
 472
 473                 $match= $magic->isMatchingExtension($extension,$mime);
 474
 475                 if ($match===NULL) {
 476                         wfDebug( __METHOD__.": no file extension known for mime type $mime, passing file\n" );
 477                         return true;
 478                 } elseif ($match===true) {
 479                         wfDebug( __METHOD__.": mime type $mime matches extension $extension, passing file\n" );
 480
 481                         #TODO: if it's a bitmap, make sure PHP or ImageMagic resp. can handle it!
 482                         return true;
 483
 484                 } else {
 485                         wfDebug( __METHOD__.": mime type $mime mismatches file extension $extension, rejecting file\n" );
 486                         return false;
 487                 }
 488         }
 489
 490         /**
 491          * Heuristic for detecting files that *could* contain JavaScript instructions or
 492          * things that may look like HTML to a browser and are thus
 493          * potentially harmful. The present implementation will produce false positives in some situations.
 494          *
 495          * @param string $file Pathname to the temporary upload file
 496          * @param string $mime The mime type of the file
 497          * @param string $extension The extension of the file
 498          * @return bool true if the file contains something looking like embedded scripts
 499          */
 500         function detectScript($file, $mime, $extension) {
 501                 global $wgAllowTitlesInSVG;
 502
 503                 #ugly hack: for text files, always look at the entire file.
 504                 #For binary field, just check the first K.
 505
 506                 if (strpos($mime,'text/')===0) $chunk = file_get_contents( $file );
 507                 else {
 508                         $fp = fopen( $file, 'rb' );
 509                         $chunk = fread( $fp, 1024 );
 510                         fclose( $fp );
 511                 }
 512
 513                 $chunk= strtolower( $chunk );
 514
 515                 if (!$chunk) return false;
 516
 517                 #decode from UTF-16 if needed (could be used for obfuscation).
 518                 if (substr($chunk,0,2)=="\xfe\xff") $enc= "UTF-16BE";
 519                 elseif (substr($chunk,0,2)=="\xff\xfe") $enc= "UTF-16LE";
 520                 else $enc= NULL;
 521
 522                 if ($enc) $chunk= iconv($enc,"ASCII//IGNORE",$chunk);
 523
 524                 $chunk= trim($chunk);
 525
 526                 #FIXME: convert from UTF-16 if necessarry!
 527
 528                 wfDebug("SpecialUpload::detectScript: checking for embedded scripts and HTML stuff\n");
 529
 530                 #check for HTML doctype
 531                 if (eregi("<!DOCTYPE *X?HTML",$chunk)) return true;
 532
 533                 /**
 534                 * Internet Explorer for Windows performs some really stupid file type
 535                 * autodetection which can cause it to interpret valid image files as HTML
 536                 * and potentially execute JavaScript, creating a cross-site scripting
 537                 * attack vectors.
 538                 *
 539                 * Apple's Safari browser also performs some unsafe file type autodetection
 540                 * which can cause legitimate files to be interpreted as HTML if the
 541                 * web server is not correctly configured to send the right content-type
 542                 * (or if you're really uploading plain text and octet streams!)
 543                 *
 544                 * Returns true if IE is likely to mistake the given file for HTML.
 545                 * Also returns true if Safari would mistake the given file for HTML
 546                 * when served with a generic content-type.
 547                 */
 548
 549                 $tags = array(
 550                         '<body',
 551                         '<head',
 552                         '<html',   #also in safari
 553                         '<img',
 554                         '<pre',
 555                         '<script', #also in safari
 556                         '<table'
 557                         );
 558                 if( ! $wgAllowTitlesInSVG && $extension !== 'svg' && $mime !== 'image/svg' ) {
 559                         $tags[] = '<title';
 560                 }
 561
 562                 foreach( $tags as $tag ) {
 563                         if( false !== strpos( $chunk, $tag ) ) {
 564                                 return true;
 565                         }
 566                 }
 567
 568                 /*
 569                 * look for javascript
 570                 */
 571
 572                 #resolve entity-refs to look at attributes. may be harsh on big files... cache result?
 573                 $chunk = Sanitizer::decodeCharReferences( $chunk );
 574
 575                 #look for script-types
 576                 if (preg_match('!type\s*=\s*[\'"]?\s*(?:\w*/)?(?:ecma|java)!sim',$chunk)) return true;
 577
 578                 #look for html-style script-urls
 579                 if (preg_match('!(?:href|src|data)\s*=\s*[\'"]?\s*(?:ecma|java)script:!sim',$chunk)) return true;
 580
 581                 #look for css-style script-urls
 582                 if (preg_match('!url\s*\(\s*[\'"]?\s*(?:ecma|java)script:!sim',$chunk)) return true;
 583
 584                 wfDebug("SpecialUpload::detectScript: no scripts found\n");
 585                 return false;
 586         }
 587
 588         /**
 589          * Generic wrapper function for a virus scanner program.
 590          * This relies on the $wgAntivirus and $wgAntivirusSetup variables.
 591          * $wgAntivirusRequired may be used to deny upload if the scan fails.
 592          *
 593          * @param string $file Pathname to the temporary upload file
 594          * @return mixed false if not virus is found, NULL if the scan fails or is disabled,
 595          *         or a string containing feedback from the virus scanner if a virus was found.
 596          *         If textual feedback is missing but a virus was found, this function returns true.
 597          */
 598         function detectVirus($file) {
 599                 global $wgAntivirus, $wgAntivirusSetup, $wgAntivirusRequired, $wgOut;
 600
 601                 if ( !$wgAntivirus ) {
 602                         wfDebug( __METHOD__.": virus scanner disabled\n");
 603                         return NULL;
 604                 }
 605
 606                 if ( !$wgAntivirusSetup[$wgAntivirus] ) {
 607                         wfDebug( __METHOD__.": unknown virus scanner: $wgAntivirus\n" );
 608                         $wgOut->wrapWikiMsg( '<div class="error">$1</div>', array( 'virus-badscanner', $wgAntivirus ) );
 609                         return wfMsg('virus-unknownscanner') . " $wgAntivirus";
 610                 }
 611
 612                 # look up scanner configuration
 613                 $command = $wgAntivirusSetup[$wgAntivirus]["command"];
 614                 $exitCodeMap = $wgAntivirusSetup[$wgAntivirus]["codemap"];
 615                 $msgPattern = isset( $wgAntivirusSetup[$wgAntivirus]["messagepattern"] ) ?
 616                         $wgAntivirusSetup[$wgAntivirus]["messagepattern"] : null;
 617
 618                 if ( strpos( $command,"%f" ) === false ) {
 619                         # simple pattern: append file to scan
 620                         $command .= " " . wfEscapeShellArg( $file );
 621                 } else {
 622                         # complex pattern: replace "%f" with file to scan
 623                         $command = str_replace( "%f", wfEscapeShellArg( $file ), $command );
 624                 }
 625
 626                 wfDebug( __METHOD__.": running virus scan: $command \n" );
 627
 628                 # execute virus scanner
 629                 $exitCode = false;
 630
 631                 #NOTE: there's a 50 line workaround to make stderr redirection work on windows, too.
 632                 #      that does not seem to be worth the pain.
 633                 #      Ask me (Duesentrieb) about it if it's ever needed.
 634                 $output = array();
 635                 if ( wfIsWindows() ) {
 636                         exec( "$command", $output, $exitCode );
 637                 } else {
 638                         exec( "$command 2>&1", $output, $exitCode );
 639                 }
 640
 641                 # map exit code to AV_xxx constants.
 642                 $mappedCode = $exitCode;
 643                 if ( $exitCodeMap ) {
 644                         if ( isset( $exitCodeMap[$exitCode] ) ) {
 645                                 $mappedCode = $exitCodeMap[$exitCode];
 646                         } elseif ( isset( $exitCodeMap["*"] ) ) {
 647                                 $mappedCode = $exitCodeMap["*"];
 648                         }
 649                 }
 650
 651                 if ( $mappedCode === AV_SCAN_FAILED ) {
 652                         # scan failed (code was mapped to false by $exitCodeMap)
 653                         wfDebug( __METHOD__.": failed to scan $file (code $exitCode).\n" );
 654
 655                         if ( $wgAntivirusRequired ) {
 656                                 return wfMsg('virus-scanfailed', array( $exitCode ) );
 657                         } else {
 658                                 return NULL;
 659                         }
 660                 } else if ( $mappedCode === AV_SCAN_ABORTED ) {
 661                         # scan failed because filetype is unknown (probably imune)
 662                         wfDebug( __METHOD__.": unsupported file type $file (code $exitCode).\n" );
 663                         return NULL;
 664                 } else if ( $mappedCode === AV_NO_VIRUS ) {
 665                         # no virus found
 666                         wfDebug( __METHOD__.": file passed virus scan.\n" );
 667                         return false;
 668                 } else {
 669                         $output = join( "\n", $output );
 670                         $output = trim( $output );
 671
 672                         if ( !$output ) {
 673                                 $output = true; #if there's no output, return true
 674                         } elseif ( $msgPattern ) {
 675                                 $groups = array();
 676                                 if ( preg_match( $msgPattern, $output, $groups ) ) {
 677                                         if ( $groups[1] ) {
 678                                                 $output = $groups[1];
 679                                         }
 680                                 }
 681                         }
 682
 683                         wfDebug( __METHOD__.": FOUND VIRUS! scanner feedback: $output" );
 684                         return $output;
 685                 }
 686         }
 687
 688         /**
 689          * Check if the temporary file is MacBinary-encoded, as some uploads
 690          * from Internet Explorer on Mac OS Classic and Mac OS X will be.
 691          * If so, the data fork will be extracted to a second temporary file,
 692          * which will then be checked for validity and either kept or discarded.
 693          *
 694          * @access private
 695          */
 696         function checkMacBinary() {
 697                 $macbin = new MacBinary( $this->mTempPath );
 698                 if( $macbin->isValid() ) {
 699                         $dataFile = tempnam( wfTempDir(), "WikiMacBinary" );
 700                         $dataHandle = fopen( $dataFile, 'wb' );
 701
 702                         wfDebug( "SpecialUpload::checkMacBinary: Extracting MacBinary data fork to $dataFile\n" );
 703                         $macbin->extractData( $dataHandle );
 704
 705                         $this->mTempPath = $dataFile;
 706                         $this->mFileSize = $macbin->dataForkLength();
 707
 708                         // We'll have to manually remove the new file if it's not kept.
 709                         $this->mRemoveTempFile = true;
 710                 }
 711                 $macbin->close();
 712         }
 713
 714         /**
 715          * Check if there's an overwrite conflict and, if so, if restrictions
 716          * forbid this user from performing the upload.
 717          *
 718          * @return mixed true on success, WikiError on failure
 719          * @access private
 720          */
 721         function checkOverwrite() {
 722                 global $wgUser;
 723                 // First check whether the local file can be overwritten
 724                 if( $this->mLocalFile->exists() )
 725                         if( !self::userCanReUpload( $wgUser, $this->mLocalFile ) )
 726                                 return 'fileexists-forbidden';
 727
 728                 // Check shared conflicts
 729                 $file = wfFindFile( $this->mLocalFile->getName() );
 730                 if ( $file && ( !$wgUser->isAllowed( 'reupload' ) ||
 731                                 !$wgUser->isAllowed( 'reupload-shared' ) ) )
 732                         return 'fileexists-shared-forbidden';
 733
 734                 return true;
 735
 736         }
 737
 738         /**
 739          * Check if a user is the last uploader
 740          *
 741          * @param User $user
 742          * @param string $img, image name
 743          * @return bool
 744          */
 745         public static function userCanReUpload( User $user, $img ) {
 746                 if( $user->isAllowed( 'reupload' ) )
 747                         return true; // non-conditional
 748                 if( !$user->isAllowed( 'reupload-own' ) )
 749                         return false;
 750                 if( is_string( $img ) )
 751                         $img = wfLocalFile( $img );
 752                 if ( !( $img instanceof LocalFile ) )
 753                         return false;
 754
 755                 return $user->getId() == $img->getUser( 'id' );
 756         }
 757
 758         public static function getExistsWarning( $file ) {
 759                 if( $file->exists() )
 760                         return array( 'exists', $file );
 761
 762                 if( $file->getTitle()->getArticleID() )
 763                         return array( 'page-exists', $file );
 764
 765                 if( strpos( $file->getName(), '.' ) == false ) {
 766                         $partname = $file->getName();
 767                         $rawExtension = '';
 768                 } else {
 769                         $n = strrpos( $file->getName(), '.' );
 770                         $rawExtension = substr( $file->getName(), $n + 1 );
 771                         $partname = substr( $file->getName(), 0, $n );
 772                 }
 773
 774                 if ( $rawExtension != $file->getExtension() ) {
 775                         // We're not using the normalized form of the extension.
 776                         // Normal form is lowercase, using most common of alternate
 777                         // extensions (eg 'jpg' rather than 'JPEG').
 778                         //
 779                         // Check for another file using the normalized form...
 780                         $nt_lc = Title::makeTitle( NS_IMAGE, $partname . '.' . $file->getExtension() );
 781                         $file_lc = wfLocalFile( $nt_lc );
 782
 783                         if( $file_lc->exists() )
 784                                 return array( 'exists-normalized', $file_lc );
 785                 }
 786
 787                 if ( self::isThumbName( $file->getName() ) ) {
 788                         # Check for filenames like 50px- or 180px-, these are mostly thumbnails
 789                         $nt_thb = Title::newFromText( substr( $partname , strpos( $partname , '-' ) +1 ) . '.' . $rawExtension );
 790                         $file_thb = wfLocalFile( $nt_thb );
 791                         if( $file_thb->exists() )
 792                                 return array( 'thumb', $file_thb );
 793                 }
 794
 795                 return false;
 796         }
 797
 798         public static function isThumbName( $filename ) {
 799                 $n = strrpos( $filename, '.' );
 800                 $partname = $n ? substr( $filename, 0, $n ) : $filename;
 801                 return (
 802                                         substr( $partname , 3, 3 ) == 'px-' ||
 803                                         substr( $partname , 2, 3 ) == 'px-'
 804                                 ) &&
 805                                 ereg( "[0-9]{2}" , substr( $partname , 0, 2) );
 806         }
 807
 808         /**
 809          * Get a list of blacklisted filename prefixes from [[MediaWiki:filename-prefix-blacklist]]
 810          *
 811          * @return array list of prefixes
 812          */
 813         public static function getFilenamePrefixBlacklist() {
 814                 $blacklist = array();
 815                 $message = wfMsgForContent( 'filename-prefix-blacklist' );
 816                 if( $message && !( wfEmptyMsg( 'filename-prefix-blacklist', $message ) || $message == '-' ) ) {
 817                         $lines = explode( "\n", $message );
 818                         foreach( $lines as $line ) {
 819                                 // Remove comment lines
 820                                 $comment = substr( trim( $line ), 0, 1 );
 821                                 if ( $comment == '#' || $comment == '' ) {
 822                                         continue;
 823                                 }
 824                                 // Remove additional comments after a prefix
 825                                 $comment = strpos( $line, '#' );
 826                                 if ( $comment > 0 ) {
 827                                         $line = substr( $line, 0, $comment-1 );
 828                                 }
 829                                 $blacklist[] = trim( $line );
 830                         }
 831                 }
 832                 return $blacklist;
 833         }
 834
 835
 836 }