includes/SpecialUpload.php

   1 <?php
   2 /**
   3  *
   4  * @package MediaWiki
   5  * @subpackage SpecialPage
   6  */
   7
   8 /**
   9  *
  10  */
  11 require_once( 'Image.php' );
  12
  13 /**
  14  * Entry point
  15  */
  16 function wfSpecialUpload() {
  17         global $wgRequest;
  18         $form = new UploadForm( $wgRequest );
  19         $form->execute();
  20 }
  21
  22 /**
  23  *
  24  * @package MediaWiki
  25  * @subpackage SpecialPage
  26  */
  27 class UploadForm {
  28         /**#@+
  29          * @access private
  30          */
  31         var $mUploadAffirm, $mUploadFile, $mUploadDescription, $mIgnoreWarning;
  32         var $mUploadSaveName, $mUploadTempName, $mUploadSize, $mUploadOldVersion;
  33         var $mUploadCopyStatus, $mUploadSource, $mReUpload, $mAction, $mUpload;
  34         var $mOname, $mSessionKey, $mStashed;
  35         /**#@-*/
  36
  37         /**
  38          * Constructor : initialise object
  39          * Get data POSTed through the form and assign them to the object
  40          * @param $request Data posted.
  41          */
  42         function UploadForm( &$request ) {
  43                 if( !$request->wasPosted() ) {
  44                         # GET requests just give the main form; no data.
  45                         return;
  46                 }
  47
  48                 $this->mUploadAffirm      = $request->getCheck( 'wpUploadAffirm' );
  49                 $this->mIgnoreWarning     = $request->getCheck( 'wpIgnoreWarning');
  50                 $this->mReUpload          = $request->getCheck( 'wpReUpload' );
  51                 $this->mUpload            = $request->getCheck( 'wpUpload' );
  52
  53                 $this->mUploadDescription = $request->getText( 'wpUploadDescription' );
  54                 $this->mUploadCopyStatus  = $request->getText( 'wpUploadCopyStatus' );
  55                 $this->mUploadSource      = $request->getText( 'wpUploadSource');
  56
  57                 $this->mAction            = $request->getVal( 'action' );
  58
  59                 $this->mSessionKey        = $request->getInt( 'wpSessionKey' );
  60                 if( !empty( $this->mSessionKey ) &&
  61                         isset( $_SESSION['wsUploadData'][$this->mSessionKey] ) ) {
  62                         /**
  63                          * Confirming a temporarily stashed upload.
  64                          * We don't want path names to be forged, so we keep
  65                          * them in the session on the server and just give
  66                          * an opaque key to the user agent.
  67                          */
  68                         $data = $_SESSION['wsUploadData'][$this->mSessionKey];
  69                         $this->mUploadTempName   = $data['mUploadTempName'];
  70                         $this->mUploadSize       = $data['mUploadSize'];
  71                         $this->mOname            = $data['mOname'];
  72                         $this->mStashed          = true;
  73                 } else {
  74                         /**
  75                          *Check for a newly uploaded file.
  76                          */
  77                         $this->mUploadTempName = $request->getFileTempName( 'wpUploadFile' );
  78                         $this->mUploadSize     = $request->getFileSize( 'wpUploadFile' );
  79                         $this->mOname          = $request->getFileName( 'wpUploadFile' );
  80                         $this->mSessionKey     = false;
  81                         $this->mStashed        = false;
  82                 }
  83         }
  84
  85         /**
  86          * Start doing stuff
  87          * @access public
  88          */
  89         function execute() {
  90                 global $wgUser, $wgOut;
  91                 global $wgDisableUploads;
  92
  93                 /** Show an error message if file upload is disabled */
  94                 if( $wgDisableUploads ) {
  95                         $wgOut->addWikiText( wfMsg( 'uploaddisabled' ) );
  96                         return;
  97                 }
  98
  99                 /** Various rights checks */
 100                 if( ( $wgUser->isAnon() )
 101                          OR $wgUser->isBlocked() ) {
 102                         $wgOut->errorpage( 'uploadnologin', 'uploadnologintext' );
 103                         return;
 104                 }
 105                 if( wfReadOnly() ) {
 106                         $wgOut->readOnlyPage();
 107                         return;
 108                 }
 109
 110                 if( $this->mReUpload ) {
 111                         $this->unsaveUploadedFile();
 112                         $this->mainUploadForm();
 113                 } else if ( 'submit' == $this->mAction || $this->mUpload ) {
 114                         $this->processUpload();
 115                 } else {
 116                         $this->mainUploadForm();
 117                 }
 118         }
 119
 120         /* -------------------------------------------------------------- */
 121
 122         /**
 123          * Really do the upload
 124          * Checks are made in SpecialUpload::execute()
 125          * @access private
 126          */
 127         function processUpload() {
 128                 global $wgUser, $wgOut, $wgLang, $wgContLang;
 129                 global $wgUploadDirectory;
 130                 global $wgUseCopyrightUpload, $wgCheckCopyrightUpload;
 131
 132                 /**
 133                  * If there was no filename or a zero size given, give up quick.
 134                  */
 135                 if( ( trim( $this->mOname ) == '' ) || empty( $this->mUploadSize ) ) {
 136                         return $this->mainUploadForm('<li>'.wfMsg( 'emptyfile' ).'</li>');
 137                 }
 138
 139                 /**
 140                  * When using detailed copyright, if user filled field, assume he
 141                  * confirmed the upload
 142                  */
 143                 if ( $wgUseCopyrightUpload ) {
 144                         $this->mUploadAffirm = true;
 145                         if( $wgCheckCopyrightUpload &&
 146                             ( trim( $this->mUploadCopyStatus ) == '' ||
 147                               trim( $this->mUploadSource     ) == '' ) ) {
 148                                 $this->mUploadAffirm = false;
 149                         }
 150                 }
 151
 152                 /** User need to confirm his upload */
 153                 if( !$this->mUploadAffirm ) {
 154                         $this->mainUploadForm( wfMsg( 'noaffirmation' ) );
 155                         return;
 156                 }
 157
 158                 # Chop off any directories in the given filename
 159                 $basename = basename( $this->mOname );
 160
 161                 /**
 162                  * We'll want to blacklist against *any* 'extension', and use
 163                  * only the final one for the whitelist.
 164                  */
 165                 list( $partname, $ext ) = $this->splitExtensions( $basename );
 166                 if( count( $ext ) ) {
 167                         $finalExt = $ext[count( $ext ) - 1];
 168                 } else {
 169                         $finalExt = '';
 170                 }
 171                 $fullExt = implode( '.', $ext );
 172
 173                 if ( strlen( $partname ) < 3 ) {
 174                         $this->mainUploadForm( wfMsg( 'minlength' ) );
 175                         return;
 176                 }
 177
 178                 /**
 179                  * Filter out illegal characters, and try to make a legible name
 180                  * out of it. We'll strip some silently that Title would die on.
 181                  */
 182                 $filtered = preg_replace ( "/[^".Title::legalChars()."]|:/", '-', $basename );
 183                 $nt = Title::newFromText( $filtered );
 184                 if( is_null( $nt ) ) {
 185                         return $this->uploadError( wfMsg( 'illegalfilename', htmlspecialchars( $filtered ) ) );
 186                 }
 187                 $nt =& Title::makeTitle( NS_IMAGE, $nt->getDBkey() );
 188                 $this->mUploadSaveName = $nt->getDBkey();
 189
 190                 /**
 191                  * If the image is protected, non-sysop users won't be able
 192                  * to modify it by uploading a new revision.
 193                  */
 194                 if( !$nt->userCanEdit() ) {
 195                         return $this->uploadError( wfMsg( 'protectedpage' ) );
 196                 }
 197
 198                 /* Don't allow users to override the blacklist */
 199                 global $wgStrictFileExtensions;
 200                 global $wgFileExtensions, $wgFileBlacklist;
 201                 if( $this->checkFileExtensionList( $ext, $wgFileBlacklist ) ||
 202                         ($wgStrictFileExtensions &&
 203                                 !$this->checkFileExtension( $finalExt, $wgFileExtensions ) ) ) {
 204                         return $this->uploadError( wfMsg( 'badfiletype', htmlspecialchars( $fullExt ) ) );
 205                 }
 206
 207                 /**
 208                  * Look at the contents of the file; if we can recognize the
 209                  * type but it's corrupt or data of the wrong type, we should
 210                  * probably not accept it.
 211                  */
 212                 if( !$this->mStashed && !$this->verify( $this->mUploadTempName, $finalExt ) ) {
 213                         return $this->uploadError( wfMsg( 'uploadcorrupt' ) );
 214                 }
 215
 216                 /**
 217                  * Check for non-fatal conditions
 218                  */
 219                 if ( ! $this->mIgnoreWarning ) {
 220                         $warning = '';
 221                         if( $this->mUploadSaveName != ucfirst( $filtered ) ) {
 222                                 $warning .=  '<li>'.wfMsg( 'badfilename', htmlspecialchars( $this->mUploadSaveName ) ).'</li>';
 223                         }
 224
 225                         global $wgCheckFileExtensions;
 226                         if ( $wgCheckFileExtensions ) {
 227                                 if ( ! $this->checkFileExtension( $finalExt, $wgFileExtensions ) ) {
 228                                         $warning .= '<li>'.wfMsg( 'badfiletype', htmlspecialchars( $fullExt ) ).'</li>';
 229                                 }
 230                         }
 231
 232                         global $wgUploadSizeWarning;
 233                         if ( $wgUploadSizeWarning && ( $this->mUploadSize > $wgUploadSizeWarning ) ) {
 234                                 $warning .= '<li>'.wfMsg( 'largefile' ).'</li>';
 235                         }
 236                         if ( $this->mUploadSize == 0 ) {
 237                                 $warning .= '<li>'.wfMsg( 'emptyfile' ).'</li>';
 238                         }
 239
 240                         if( $nt->getArticleID() ) {
 241                                 global $wgUser;
 242                                 $sk = $wgUser->getSkin();
 243                                 $dlink = $sk->makeKnownLinkObj( $nt );
 244                                 $warning .= '<li>'.wfMsg( 'fileexists', $dlink ).'</li>';
 245                         }
 246
 247                         if( $warning != '' ) {
 248                                 /**
 249                                  * Stash the file in a temporary location; the user can choose
 250                                  * to let it through and we'll complete the upload then.
 251                                  */
 252                                 return $this->uploadWarning($warning);
 253                         }
 254                 }
 255
 256                 /**
 257                  * Try actually saving the thing...
 258                  * It will show an error form on failure.
 259                  */
 260                 if( $this->saveUploadedFile( $this->mUploadSaveName,
 261                                              $this->mUploadTempName,
 262                                              !empty( $this->mSessionKey ) ) ) {
 263                         /**
 264                          * Update the upload log and create the description page
 265                          * if it's a new file.
 266                          */
 267                         wfRecordUpload( $this->mUploadSaveName,
 268                                         $this->mUploadOldVersion,
 269                                         $this->mUploadSize,
 270                                         $this->mUploadDescription,
 271                                         $this->mUploadCopyStatus,
 272                                         $this->mUploadSource );
 273
 274                         /* refresh image metadata cache */
 275                         new Image( $this->mUploadSaveName, true );
 276
 277                         $this->showSuccess();
 278                 }
 279         }
 280
 281         /**
 282          * Move the uploaded file from its temporary location to the final
 283          * destination. If a previous version of the file exists, move
 284          * it into the archive subdirectory.
 285          *
 286          * @todo If the later save fails, we may have disappeared the original file.
 287          *
 288          * @param string $saveName
 289          * @param string $tempName full path to the temporary file
 290          * @param bool $useRename if true, doesn't check that the source file
 291          *                        is a PHP-managed upload temporary
 292          */
 293         function saveUploadedFile( $saveName, $tempName, $useRename = false ) {
 294                 global $wgUploadDirectory, $wgOut;
 295
 296                 $dest = wfImageDir( $saveName );
 297                 $archive = wfImageArchiveDir( $saveName );
 298                 $this->mSavedFile = "{$dest}/{$saveName}";
 299
 300                 if( is_file( $this->mSavedFile ) ) {
 301                         $this->mUploadOldVersion = gmdate( 'YmdHis' ) . "!{$saveName}";
 302
 303                         if( @!rename( $this->mSavedFile, "${archive}/{$this->mUploadOldVersion}" ) ) {
 304                                 $wgOut->fileRenameError( $this->mSavedFile,
 305                                   "${archive}/{$this->mUploadOldVersion}" );
 306                                 return false;
 307                         }
 308                 } else {
 309                         $this->mUploadOldVersion = '';
 310                 }
 311
 312                 if( $useRename ) {
 313                         if( @!rename( $tempName, $this->mSavedFile ) ) {
 314                                 $wgOut->fileCopyError( $tempName, $this->mSavedFile );
 315                                 return false;
 316                         }
 317                 } else {
 318                         if( @!move_uploaded_file( $tempName, $this->mSavedFile ) ) {
 319                                 $wgOut->fileCopyError( $tempName, $this->mSavedFile );
 320                                 return false;
 321                         }
 322                 }
 323                 chmod( $this->mSavedFile, 0644 );
 324                 return true;
 325         }
 326
 327         /**
 328          * Stash a file in a temporary directory for later processing
 329          * after the user has confirmed it.
 330          *
 331          * If the user doesn't explicitly cancel or accept, these files
 332          * can accumulate in the temp directory.
 333          *
 334          * @param string $saveName - the destination filename
 335          * @param string $tempName - the source temporary file to save
 336          * @return string - full path the stashed file, or false on failure
 337          * @access private
 338          */
 339         function saveTempUploadedFile( $saveName, $tempName ) {
 340                 global $wgOut;
 341                 $archive = wfImageArchiveDir( $saveName, 'temp' );
 342                 $stash = $archive . '/' . gmdate( "YmdHis" ) . '!' . $saveName;
 343
 344                 if ( !move_uploaded_file( $tempName, $stash ) ) {
 345                         $wgOut->fileCopyError( $tempName, $stash );
 346                         return false;
 347                 }
 348
 349                 return $stash;
 350         }
 351
 352         /**
 353          * Stash a file in a temporary directory for later processing,
 354          * and save the necessary descriptive info into the session.
 355          * Returns a key value which will be passed through a form
 356          * to pick up the path info on a later invocation.
 357          *
 358          * @return int
 359          * @access private
 360          */
 361         function stashSession() {
 362                 $stash = $this->saveTempUploadedFile(
 363                         $this->mUploadSaveName, $this->mUploadTempName );
 364
 365                 if( !$stash ) {
 366                         # Couldn't save the file.
 367                         return false;
 368                 }
 369
 370                 $key = mt_rand( 0, 0x7fffffff );
 371                 $_SESSION['wsUploadData'][$key] = array(
 372                         'mUploadTempName' => $stash,
 373                         'mUploadSize'     => $this->mUploadSize,
 374                         'mOname'          => $this->mOname );
 375                 return $key;
 376         }
 377
 378         /**
 379          * Remove a temporarily kept file stashed by saveTempUploadedFile().
 380          * @access private
 381          */
 382         function unsaveUploadedFile() {
 383                 if ( ! @unlink( $this->mUploadTempName ) ) {
 384                         $wgOut->fileDeleteError( $this->mUploadTempName );
 385                 }
 386         }
 387
 388         /* -------------------------------------------------------------- */
 389
 390         /**
 391          * Show some text and linkage on successful upload.
 392          * @access private
 393          */
 394         function showSuccess() {
 395                 global $wgUser, $wgOut, $wgContLang;
 396
 397                 $sk = $wgUser->getSkin();
 398                 $ilink = $sk->makeMediaLink( $this->mUploadSaveName, Image::wfImageUrl( $this->mUploadSaveName ) );
 399                 $dname = $wgContLang->getNsText( NS_IMAGE ) . ':'.$this->mUploadSaveName;
 400                 $dlink = $sk->makeKnownLink( $dname, $dname );
 401
 402                 $wgOut->addHTML( '<h2>' . wfMsg( 'successfulupload' ) . "</h2>\n" );
 403                 $text = wfMsg( 'fileuploaded', $ilink, $dlink );
 404                 $wgOut->addHTML( '<p>'.$text."\n" );
 405                 $wgOut->returnToMain( false );
 406         }
 407
 408         /**
 409          * @param string $error as HTML
 410          * @access private
 411          */
 412         function uploadError( $error ) {
 413                 global $wgOut;
 414                 $sub = wfMsg( 'uploadwarning' );
 415                 $wgOut->addHTML( "<h2>{$sub}</h2>\n" );
 416                 $wgOut->addHTML( "<h4 class='error'>{$error}</h4>\n" );
 417         }
 418
 419         /**
 420          * There's something wrong with this file, not enough to reject it
 421          * totally but we require manual intervention to save it for real.
 422          * Stash it away, then present a form asking to confirm or cancel.
 423          *
 424          * @param string $warning as HTML
 425          * @access private
 426          */
 427         function uploadWarning( $warning ) {
 428                 global $wgOut, $wgUser, $wgLang, $wgUploadDirectory, $wgRequest;
 429                 global $wgUseCopyrightUpload;
 430
 431                 $this->mSessionKey = $this->stashSession();
 432                 if( !$this->mSessionKey ) {
 433                         # Couldn't save file; an error has been displayed so let's go.
 434                         return;
 435                 }
 436
 437                 $sub = wfMsg( 'uploadwarning' );
 438                 $wgOut->addHTML( "<h2>{$sub}</h2>\n" );
 439                 $wgOut->addHTML( "<ul class='warning'>{$warning}</ul><br />\n" );
 440
 441                 $save = wfMsg( 'savefile' );
 442                 $reupload = wfMsg( 'reupload' );
 443                 $iw = wfMsg( 'ignorewarning' );
 444                 $reup = wfMsg( 'reuploaddesc' );
 445                 $titleObj = Title::makeTitle( NS_SPECIAL, 'Upload' );
 446                 $action = $titleObj->escapeLocalURL( 'action=submit' );
 447
 448                 if ( $wgUseCopyrightUpload )
 449                 {
 450                         $copyright =  "
 451         <input type='hidden' name=\"wpUploadCopyStatus\" value=\"" . htmlspecialchars( $this->mUploadCopyStatus ) . "\" />
 452         <input type='hidden' name=\"wpUploadSource\" value=\"" . htmlspecialchars( $this->mUploadSource ) . "\" />
 453         ";
 454                 } else {
 455                         $copyright = "";
 456                 }
 457
 458                 $wgOut->addHTML( "
 459         <form id=\"uploadwarning\" method=\"post\" enctype=\"multipart/form-data\"
 460         action=\"{$action}\">
 461         <input type=hidden name=\"wpUploadAffirm\" value=\"1\" />
 462         <input type=hidden name=\"wpIgnoreWarning\" value=\"1\" />
 463         <input type=hidden name=\"wpSessionKey\" value=\"" . htmlspecialchars( $this->mSessionKey ) . "\" />
 464         <input type=hidden name=\"wpUploadDescription\" value=\"" . htmlspecialchars( $this->mUploadDescription ) . "\" />
 465         {$copyright}
 466         <table border='0'><tr>
 467         <tr><td align='right'>
 468         <input tabindex='2' type='submit' name=\"wpUpload\" value=\"{$save}\" />
 469         </td><td align='left'>{$iw}</td></tr>
 470         <tr><td align='right'>
 471         <input tabindex='2' type='submit' name=\"wpReUpload\" value=\"{$reupload}\" />
 472         </td><td align='left'>{$reup}</td></tr></table></form>\n" );
 473         }
 474
 475         /**
 476          * Displays the main upload form, optionally with a highlighted
 477          * error message up at the top.
 478          *
 479          * @param string $msg as HTML
 480          * @access private
 481          */
 482         function mainUploadForm( $msg='' ) {
 483                 global $wgOut, $wgUser, $wgLang, $wgUploadDirectory, $wgRequest;
 484                 global $wgUseCopyrightUpload;
 485
 486                 if ( '' != $msg ) {
 487                         $sub = wfMsg( 'uploaderror' );
 488                         $wgOut->addHTML( "<h2>{$sub}</h2>\n" .
 489                           "<h4 class='error'>{$msg}</h4>\n" );
 490                 } else {
 491                         $sub = wfMsg( 'uploadfile' );
 492                         $wgOut->addHTML( "<h2>{$sub}</h2>\n" );
 493                 }
 494                 $wgOut->addWikiText( wfMsg( 'uploadtext' ) );
 495                 $sk = $wgUser->getSkin();
 496
 497                 $fn = wfMsg( 'filename' );
 498                 $fd = wfMsg( 'filedesc' );
 499                 $ulb = wfMsg( 'uploadbtn' );
 500
 501                 $clink = $sk->makeKnownLink( wfMsgForContent( 'copyrightpage' ),
 502                   wfMsg( 'copyrightpagename' ) );
 503                 $ca = wfMsg( 'affirmation', $clink );
 504                 $iw = wfMsg( 'ignorewarning' );
 505
 506                 $titleObj = Title::makeTitle( NS_SPECIAL, 'Upload' );
 507                 $action = $titleObj->escapeLocalURL();
 508
 509                 $source = "
 510         <td align='right'>
 511         <input tabindex='3' type='checkbox' name=\"wpUploadAffirm\" value=\"1\" id=\"wpUploadAffirm\" />
 512         </td><td align='left'><label for=\"wpUploadAffirm\">{$ca}</label></td>
 513         " ;
 514                 if ( $wgUseCopyrightUpload )
 515                   {
 516                         $source = "
 517         <td align='right' nowrap='nowrap'>" . wfMsg ( 'filestatus' ) . ":</td>
 518         <td><input tabindex='3' type='text' name=\"wpUploadCopyStatus\" value=\"" .
 519         htmlspecialchars($this->mUploadCopyStatus). "\" size='40' /></td>
 520         </tr><tr>
 521         <td align='right'>". wfMsg ( 'filesource' ) . ":</td>
 522         <td><input tabindex='4' type='text' name=\"wpUploadSource\" value=\"" .
 523         htmlspecialchars($this->mUploadSource). "\" size='40' /></td>
 524         " ;
 525                   }
 526
 527                 $wgOut->addHTML( "
 528         <form id=\"upload\" method=\"post\" enctype=\"multipart/form-data\"
 529         action=\"{$action}\">
 530         <table border='0'><tr>
 531         <td align='right'>{$fn}:</td><td align='left'>
 532         <input tabindex='1' type='file' name=\"wpUploadFile\" size='40' />
 533         </td></tr><tr>
 534         <td align='right'>{$fd}:</td><td align='left'>
 535         <input tabindex='2' type='text' name=\"wpUploadDescription\" value=\""
 536           . htmlspecialchars( $this->mUploadDescription ) . "\" size='40' />
 537         </td></tr><tr>
 538         {$source}
 539         </tr>
 540         <tr><td></td><td align='left'>
 541         <input tabindex='5' type='submit' name=\"wpUpload\" value=\"{$ulb}\" />
 542         </td></tr></table></form>\n" );
 543         }
 544
 545         /* -------------------------------------------------------------- */
 546
 547         /**
 548          * Split a file into a base name and all dot-delimited 'extensions'
 549          * on the end. Some web server configurations will fall back to
 550          * earlier pseudo-'extensions' to determine type and execute
 551          * scripts, so the blacklist needs to check them all.
 552          *
 553          * @return array
 554          */
 555         function splitExtensions( $filename ) {
 556                 $bits = explode( '.', $filename );
 557                 $basename = array_shift( $bits );
 558                 return array( $basename, $bits );
 559         }
 560
 561         /**
 562          * Perform case-insensitive match against a list of file extensions.
 563          * Returns true if the extension is in the list.
 564          *
 565          * @param string $ext
 566          * @param array $list
 567          * @return bool
 568          */
 569         function checkFileExtension( $ext, $list ) {
 570                 return in_array( strtolower( $ext ), $list );
 571         }
 572
 573         /**
 574          * Perform case-insensitive match against a list of file extensions.
 575          * Returns true if any of the extensions are in the list.
 576          *
 577          * @param array $ext
 578          * @param array $list
 579          * @return bool
 580          */
 581         function checkFileExtensionList( $ext, $list ) {
 582                 foreach( $ext as $e ) {
 583                         if( in_array( strtolower( $e ), $list ) ) {
 584                                 return true;
 585                         }
 586                 }
 587                 return false;
 588         }
 589
 590         /**
 591          * Returns false if the file is of a known type but can't be recognized,
 592          * indicating a corrupt file.
 593          * Returns true otherwise; unknown file types are not checked if given
 594          * with an unrecognized extension.
 595          *
 596          * @param string $tmpfile Pathname to the temporary upload file
 597          * @param string $extension The filename extension that the file is to be served with
 598          * @return bool
 599          */
 600         function verify( $tmpfile, $extension ) {
 601                 if( $this->triggersIEbug( $tmpfile ) ||
 602                     $this->triggersSafariBug( $tmpfile ) ) {
 603                         return false;
 604                 }
 605
 606                 $fname = 'SpecialUpload::verify';
 607                 $mergeExtensions = array(
 608                         'jpg' => 'jpeg',
 609                         'tif' => 'tiff' );
 610                 $extensionTypes = array(
 611                         # See http://www.php.net/getimagesize
 612                         1 => 'gif',
 613                         2 => 'jpeg',
 614                         3 => 'png',
 615                         4 => 'swf',
 616                         5 => 'psd',
 617                         6 => 'bmp',
 618                         7 => 'tiff',
 619                         8 => 'tiff',
 620                         9 => 'jpc',
 621                         10 => 'jp2',
 622                         11 => 'jpx',
 623                         12 => 'jb2',
 624                         13 => 'swc',
 625                         14 => 'iff',
 626                         15 => 'wbmp',
 627                         16 => 'xbm' );
 628
 629                 $extension = strtolower( $extension );
 630                 if( isset( $mergeExtensions[$extension] ) ) {
 631                         $extension = $mergeExtensions[$extension];
 632                 }
 633                 wfDebug( "$fname: Testing file '$tmpfile' with given extension '$extension'\n" );
 634
 635                 if( !in_array( $extension, $extensionTypes ) ) {
 636                         # Not a recognized image type. We don't know how to verify these.
 637                         # They're allowed by policy or they wouldn't get this far, so we'll
 638                         # let them slide for now.
 639                         wfDebug( "$fname: Unknown extension; passing.\n" );
 640                         return true;
 641                 }
 642
 643                 $data = @getimagesize( $tmpfile );
 644                 if( false === $data ) {
 645                         # Didn't recognize the image type.
 646                         # Either the image is corrupt or someone's slipping us some
 647                         # bogus data such as HTML+JavaScript trying to take advantage
 648                         # of an Internet Explorer security flaw.
 649                         wfDebug( "$fname: getimagesize() doesn't recognize the file; rejecting.\n" );
 650                         return false;
 651                 }
 652
 653                 $imageType = $data[2];
 654                 if( !isset( $extensionTypes[$imageType] ) ) {
 655                         # Now we're kind of confused. Perhaps new image types added
 656                         # to PHP's support that we don't know about.
 657                         # We'll let these slide for now.
 658                         wfDebug( "$fname: getimagesize() knows the file, but we don't recognize the type; passing.\n" );
 659                         return true;
 660                 }
 661
 662                 $ext = strtolower( $extension );
 663                 if( $extension != $extensionTypes[$imageType] ) {
 664                         # The given filename extension doesn't match the
 665                         # file type. Probably just a mistake, but it's a stupid
 666                         # one and we shouldn't let it pass. KILL THEM!
 667                         wfDebug( "$fname: file extension does not match recognized type; rejecting.\n" );
 668                         return false;
 669                 }
 670
 671                 wfDebug( "$fname: all clear; passing.\n" );
 672                 return true;
 673         }
 674
 675         /**
 676          * Internet Explorer for Windows performs some really stupid file type
 677          * autodetection which can cause it to interpret valid image files as HTML
 678          * and potentially execute JavaScript, creating a cross-site scripting
 679          * attack vectors.
 680          *
 681          * Returns true if IE is likely to mistake the given file for HTML.
 682          *
 683          * @param string $filename
 684          * @return bool
 685          */
 686         function triggersIEbug( $filename ) {
 687                 $file = fopen( $filename, 'rb' );
 688                 $chunk = strtolower( fread( $file, 256 ) );
 689                 fclose( $file );
 690
 691                 $tags = array(
 692                         '<body',
 693                         '<head',
 694                         '<html',
 695                         '<img',
 696                         '<pre',
 697                         '<script',
 698                         '<table',
 699                         '<title' );
 700                 foreach( $tags as $tag ) {
 701                         if( false !== strpos( $chunk, $tag ) ) {
 702                                 return true;
 703                         }
 704                 }
 705                 return false;
 706         }
 707
 708         /**
 709          * Apple's Safari browser performs some unsafe file type autodetection
 710          * which can cause legitimate files to be interpreted as HTML if the
 711          * web server is not correctly configured to send the right content-type
 712          * (or if you're really uploading plain text and octet streams!)
 713          *
 714          * Returns true if Safari would mistake the given file for HTML
 715          * when served with a generic content-type.
 716          *
 717          * @param string $filename
 718          * @return bool
 719          */
 720         function triggersSafariBug( $filename ) {
 721                 $file = fopen( $filename, 'rb' );
 722                 $chunk = strtolower( fread( $file, 1024 ) );
 723                 fclose( $file );
 724
 725                 $tags = array(
 726                         '<html',
 727                         '<script',
 728                         '<title' );
 729                 foreach( $tags as $tag ) {
 730                         if( false !== strpos( $chunk, $tag ) ) {
 731                                 return true;
 732                         }
 733                 }
 734                 return false;
 735         }
 736
 737 }
 738 ?>