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, $mDestFile;
  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                 $this->mDestFile          = $request->getText( 'wpDestFile' );
  44
  45                 if( !$request->wasPosted() ) {
  46                         # GET requests just give the main form; no data except wpDestfile.
  47                         return;
  48                 }
  49
  50                 $this->mUploadAffirm      = $request->getCheck( 'wpUploadAffirm' );
  51                 $this->mIgnoreWarning     = $request->getCheck( 'wpIgnoreWarning');
  52                 $this->mReUpload          = $request->getCheck( 'wpReUpload' );
  53                 $this->mUpload            = $request->getCheck( 'wpUpload' );
  54
  55                 $this->mUploadDescription = $request->getText( 'wpUploadDescription' );
  56                 $this->mUploadCopyStatus  = $request->getText( 'wpUploadCopyStatus' );
  57                 $this->mUploadSource      = $request->getText( 'wpUploadSource');
  58
  59                 $this->mAction            = $request->getVal( 'action' );
  60
  61                 $this->mSessionKey        = $request->getInt( 'wpSessionKey' );
  62                 if( !empty( $this->mSessionKey ) &&
  63                         isset( $_SESSION['wsUploadData'][$this->mSessionKey] ) ) {
  64                         /**
  65                          * Confirming a temporarily stashed upload.
  66                          * We don't want path names to be forged, so we keep
  67                          * them in the session on the server and just give
  68                          * an opaque key to the user agent.
  69                          */
  70                         $data = $_SESSION['wsUploadData'][$this->mSessionKey];
  71                         $this->mUploadTempName   = $data['mUploadTempName'];
  72                         $this->mUploadSize       = $data['mUploadSize'];
  73                         $this->mOname            = $data['mOname'];
  74                         $this->mStashed          = true;
  75                 } else {
  76                         /**
  77                          *Check for a newly uploaded file.
  78                          */
  79                         $this->mUploadTempName = $request->getFileTempName( 'wpUploadFile' );
  80                         $this->mUploadSize     = $request->getFileSize( 'wpUploadFile' );
  81                         $this->mOname          = $request->getFileName( 'wpUploadFile' );
  82                         $this->mSessionKey     = false;
  83                         $this->mStashed        = false;
  84                 }
  85         }
  86
  87         /**
  88          * Start doing stuff
  89          * @access public
  90          */
  91         function execute() {
  92                 global $wgUser, $wgOut;
  93                 global $wgEnableUploads, $wgUploadDirectory;
  94
  95                 /** Show an error message if file upload is disabled */
  96                 if( ! $wgEnableUploads ) {
  97                         $wgOut->addWikiText( wfMsg( 'uploaddisabled' ) );
  98                         return;
  99                 }
 100
 101                 /** Various rights checks */
 102                 if( ( $wgUser->isAnon() )
 103                          OR $wgUser->isBlocked() ) {
 104                         $wgOut->errorpage( 'uploadnologin', 'uploadnologintext' );
 105                         return;
 106                 }
 107                 if( wfReadOnly() ) {
 108                         $wgOut->readOnlyPage();
 109                         return;
 110                 }
 111
 112                 /** Check if the image directory is writeable, this is a common mistake */
 113                 if ( !is_writeable( $wgUploadDirectory ) ) {
 114                         $wgOut->addWikiText( wfMsg( 'upload_directory_read_only', $wgUploadDirectory ) );
 115                         return;
 116                 }
 117
 118                 if( $this->mReUpload ) {
 119                         $this->unsaveUploadedFile();
 120                         $this->mainUploadForm();
 121                 } else if ( 'submit' == $this->mAction || $this->mUpload ) {
 122                         $this->processUpload();
 123                 } else {
 124                         $this->mainUploadForm();
 125                 }
 126         }
 127
 128         /* -------------------------------------------------------------- */
 129
 130         /**
 131          * Really do the upload
 132          * Checks are made in SpecialUpload::execute()
 133          * @access private
 134          */
 135         function processUpload() {
 136                 global $wgUser, $wgOut, $wgLang, $wgContLang;
 137                 global $wgUploadDirectory;
 138                 global $wgUseCopyrightUpload, $wgCheckCopyrightUpload;
 139
 140                 /**
 141                  * If there was no filename or a zero size given, give up quick.
 142                  */
 143                 if( trim( $this->mOname ) == '' || empty( $this->mUploadSize ) ) {
 144                         return $this->mainUploadForm('<li>'.wfMsg( 'emptyfile' ).'</li>');
 145                 }
 146
 147                 /**
 148                  * When using detailed copyright, if user filled field, assume he
 149                  * confirmed the upload
 150                  */
 151                 if ( $wgUseCopyrightUpload ) {
 152                         $this->mUploadAffirm = true;
 153                         if( $wgCheckCopyrightUpload &&
 154                             ( trim( $this->mUploadCopyStatus ) == '' ||
 155                               trim( $this->mUploadSource     ) == '' ) ) {
 156                                 $this->mUploadAffirm = false;
 157                         }
 158                 }
 159
 160                 /** User need to confirm his upload */
 161                 if( !$this->mUploadAffirm ) {
 162                         $this->mainUploadForm( wfMsg( 'noaffirmation' ) );
 163                         return;
 164                 }
 165
 166                 # Chop off any directories in the given filename
 167                 if ( $this->mDestFile ) {
 168                         $basename = basename( $this->mDestFile );
 169                 } else {
 170                         $basename = basename( $this->mOname );
 171                 }
 172
 173                 /**
 174                  * We'll want to blacklist against *any* 'extension', and use
 175                  * only the final one for the whitelist.
 176                  */
 177                 list( $partname, $ext ) = $this->splitExtensions( $basename );
 178                 if( count( $ext ) ) {
 179                         $finalExt = $ext[count( $ext ) - 1];
 180                 } else {
 181                         $finalExt = '';
 182                 }
 183                 $fullExt = implode( '.', $ext );
 184
 185                 if ( strlen( $partname ) < 3 ) {
 186                         $this->mainUploadForm( wfMsg( 'minlength' ) );
 187                         return;
 188                 }
 189
 190                 /**
 191                  * Filter out illegal characters, and try to make a legible name
 192                  * out of it. We'll strip some silently that Title would die on.
 193                  */
 194                 $filtered = preg_replace ( "/[^".Title::legalChars()."]|:/", '-', $basename );
 195                 $nt = Title::newFromText( $filtered );
 196                 if( is_null( $nt ) ) {
 197                         return $this->uploadError( wfMsg( 'illegalfilename', htmlspecialchars( $filtered ) ) );
 198                 }
 199                 $nt =& Title::makeTitle( NS_IMAGE, $nt->getDBkey() );
 200                 $this->mUploadSaveName = $nt->getDBkey();
 201
 202                 /**
 203                  * If the image is protected, non-sysop users won't be able
 204                  * to modify it by uploading a new revision.
 205                  */
 206                 if( !$nt->userCanEdit() ) {
 207                         return $this->uploadError( wfMsg( 'protectedpage' ) );
 208                 }
 209
 210                 /* Don't allow users to override the blacklist */
 211                 global $wgStrictFileExtensions;
 212                 global $wgFileExtensions, $wgFileBlacklist;
 213                 if( $this->checkFileExtensionList( $ext, $wgFileBlacklist ) ||
 214                         ($wgStrictFileExtensions &&
 215                                 !$this->checkFileExtension( $finalExt, $wgFileExtensions ) ) ) {
 216                         return $this->uploadError( wfMsg( 'badfiletype', htmlspecialchars( $fullExt ) ) );
 217                 }
 218
 219                 /**
 220                  * Look at the contents of the file; if we can recognize the
 221                  * type but it's corrupt or data of the wrong type, we should
 222                  * probably not accept it.
 223                  */
 224                 if( !$this->mStashed && !$this->verify( $this->mUploadTempName, $finalExt ) ) {
 225                         return $this->uploadError( wfMsg( 'uploadcorrupt' ) );
 226                 }
 227
 228                 /**
 229                  * Check for non-fatal conditions
 230                  */
 231                 if ( ! $this->mIgnoreWarning ) {
 232                         $warning = '';
 233                         if( $this->mUploadSaveName != ucfirst( $filtered ) ) {
 234                                 $warning .=  '<li>'.wfMsg( 'badfilename', htmlspecialchars( $this->mUploadSaveName ) ).'</li>';
 235                         }
 236
 237                         global $wgCheckFileExtensions;
 238                         if ( $wgCheckFileExtensions ) {
 239                                 if ( ! $this->checkFileExtension( $finalExt, $wgFileExtensions ) ) {
 240                                         $warning .= '<li>'.wfMsg( 'badfiletype', htmlspecialchars( $fullExt ) ).'</li>';
 241                                 }
 242                         }
 243
 244                         global $wgUploadSizeWarning;
 245                         if ( $wgUploadSizeWarning && ( $this->mUploadSize > $wgUploadSizeWarning ) ) {
 246                                 # TODO: Format $wgUploadSizeWarning to something that looks better than the raw byte
 247                                 # value, perhaps add GB,MB and KB suffixes?
 248                                 $warning .= '<li>'.wfMsg( 'largefile', $wgUploadSizeWarning, $this->mUploadSize ).'</li>';
 249                         }
 250                         if ( $this->mUploadSize == 0 ) {
 251                                 $warning .= '<li>'.wfMsg( 'emptyfile' ).'</li>';
 252                         }
 253
 254                         if( $nt->getArticleID() ) {
 255                                 global $wgUser;
 256                                 $sk = $wgUser->getSkin();
 257                                 $dlink = $sk->makeKnownLinkObj( $nt );
 258                                 $warning .= '<li>'.wfMsg( 'fileexists', $dlink ).'</li>';
 259                         }
 260
 261                         if( $warning != '' ) {
 262                                 /**
 263                                  * Stash the file in a temporary location; the user can choose
 264                                  * to let it through and we'll complete the upload then.
 265                                  */
 266                                 return $this->uploadWarning($warning);
 267                         }
 268                 }
 269
 270                 /**
 271                  * Try actually saving the thing...
 272                  * It will show an error form on failure.
 273                  */
 274                 if( $this->saveUploadedFile( $this->mUploadSaveName,
 275                                              $this->mUploadTempName,
 276                                              !empty( $this->mSessionKey ) ) ) {
 277                         /**
 278                          * Update the upload log and create the description page
 279                          * if it's a new file.
 280                          */
 281                         $img = Image::newFromName( $this->mUploadSaveName );
 282                         $success = $img->recordUpload( $this->mUploadOldVersion,
 283                                                         $this->mUploadDescription,
 284                                                         $this->mUploadCopyStatus,
 285                                                         $this->mUploadSource );
 286
 287                         if ( $success ) {
 288                                 $this->showSuccess();
 289                         } else {
 290                                 // Image::recordUpload() fails if the image went missing, which is
 291                                 // unlikely, hence the lack of a specialised message
 292                                 $wgOut->fileNotFoundError( $this->mUploadSaveName );
 293                         }
 294                 }
 295         }
 296
 297         /**
 298          * Move the uploaded file from its temporary location to the final
 299          * destination. If a previous version of the file exists, move
 300          * it into the archive subdirectory.
 301          *
 302          * @todo If the later save fails, we may have disappeared the original file.
 303          *
 304          * @param string $saveName
 305          * @param string $tempName full path to the temporary file
 306          * @param bool $useRename if true, doesn't check that the source file
 307          *                        is a PHP-managed upload temporary
 308          */
 309         function saveUploadedFile( $saveName, $tempName, $useRename = false ) {
 310                 global $wgUploadDirectory, $wgOut;
 311
 312                 $dest = wfImageDir( $saveName );
 313                 $archive = wfImageArchiveDir( $saveName );
 314                 $this->mSavedFile = "{$dest}/{$saveName}";
 315
 316                 if( is_file( $this->mSavedFile ) ) {
 317                         $this->mUploadOldVersion = gmdate( 'YmdHis' ) . "!{$saveName}";
 318                         wfSuppressWarnings();
 319                         $success = rename( $this->mSavedFile, "${archive}/{$this->mUploadOldVersion}" );
 320                         wfRestoreWarnings();
 321
 322                         if( ! $success ) {
 323                                 $wgOut->fileRenameError( $this->mSavedFile,
 324                                   "${archive}/{$this->mUploadOldVersion}" );
 325                                 return false;
 326                         }
 327                 } else {
 328                         $this->mUploadOldVersion = '';
 329                 }
 330
 331                 if( $useRename ) {
 332                         wfSuppressWarnings();
 333                         $success = rename( $tempName, $this->mSavedFile );
 334                         wfRestoreWarnings();
 335
 336                         if( ! $success ) {
 337                                 $wgOut->fileCopyError( $tempName, $this->mSavedFile );
 338                                 return false;
 339                         }
 340                 } else {
 341                         wfSuppressWarnings();
 342                         $success = move_uploaded_file( $tempName, $this->mSavedFile );
 343                         wfRestoreWarnings();
 344
 345                         if( ! $success ) {
 346                                 $wgOut->fileCopyError( $tempName, $this->mSavedFile );
 347                                 return false;
 348                         }
 349                 }
 350                 chmod( $this->mSavedFile, 0644 );
 351                 return true;
 352         }
 353
 354         /**
 355          * Stash a file in a temporary directory for later processing
 356          * after the user has confirmed it.
 357          *
 358          * If the user doesn't explicitly cancel or accept, these files
 359          * can accumulate in the temp directory.
 360          *
 361          * @param string $saveName - the destination filename
 362          * @param string $tempName - the source temporary file to save
 363          * @return string - full path the stashed file, or false on failure
 364          * @access private
 365          */
 366         function saveTempUploadedFile( $saveName, $tempName ) {
 367                 global $wgOut;
 368                 $archive = wfImageArchiveDir( $saveName, 'temp' );
 369                 $stash = $archive . '/' . gmdate( "YmdHis" ) . '!' . $saveName;
 370
 371                 if ( !move_uploaded_file( $tempName, $stash ) ) {
 372                         $wgOut->fileCopyError( $tempName, $stash );
 373                         return false;
 374                 }
 375
 376                 return $stash;
 377         }
 378
 379         /**
 380          * Stash a file in a temporary directory for later processing,
 381          * and save the necessary descriptive info into the session.
 382          * Returns a key value which will be passed through a form
 383          * to pick up the path info on a later invocation.
 384          *
 385          * @return int
 386          * @access private
 387          */
 388         function stashSession() {
 389                 $stash = $this->saveTempUploadedFile(
 390                         $this->mUploadSaveName, $this->mUploadTempName );
 391
 392                 if( !$stash ) {
 393                         # Couldn't save the file.
 394                         return false;
 395                 }
 396
 397                 $key = mt_rand( 0, 0x7fffffff );
 398                 $_SESSION['wsUploadData'][$key] = array(
 399                         'mUploadTempName' => $stash,
 400                         'mUploadSize'     => $this->mUploadSize,
 401                         'mOname'          => $this->mOname );
 402                 return $key;
 403         }
 404
 405         /**
 406          * Remove a temporarily kept file stashed by saveTempUploadedFile().
 407          * @access private
 408          */
 409         function unsaveUploadedFile() {
 410                 wfSuppressWarnings();
 411                 $success = unlink( $this->mUploadTempName );
 412                 wfRestoreWarnings();
 413                 if ( ! $success ) {
 414                         $wgOut->fileDeleteError( $this->mUploadTempName );
 415                 }
 416         }
 417
 418         /* -------------------------------------------------------------- */
 419
 420         /**
 421          * Show some text and linkage on successful upload.
 422          * @access private
 423          */
 424         function showSuccess() {
 425                 global $wgUser, $wgOut, $wgContLang;
 426
 427                 $sk = $wgUser->getSkin();
 428                 $ilink = $sk->makeMediaLink( $this->mUploadSaveName, Image::imageUrl( $this->mUploadSaveName ) );
 429                 $dname = $wgContLang->getNsText( NS_IMAGE ) . ':'.$this->mUploadSaveName;
 430                 $dlink = $sk->makeKnownLink( $dname, $dname );
 431
 432                 $wgOut->addHTML( '<h2>' . wfMsg( 'successfulupload' ) . "</h2>\n" );
 433                 $text = wfMsg( 'fileuploaded', $ilink, $dlink );
 434                 $wgOut->addHTML( '<p>'.$text."\n" );
 435                 $wgOut->returnToMain( false );
 436         }
 437
 438         /**
 439          * @param string $error as HTML
 440          * @access private
 441          */
 442         function uploadError( $error ) {
 443                 global $wgOut;
 444                 $sub = wfMsg( 'uploadwarning' );
 445                 $wgOut->addHTML( "<h2>{$sub}</h2>\n" );
 446                 $wgOut->addHTML( "<h4 class='error'>{$error}</h4>\n" );
 447         }
 448
 449         /**
 450          * There's something wrong with this file, not enough to reject it
 451          * totally but we require manual intervention to save it for real.
 452          * Stash it away, then present a form asking to confirm or cancel.
 453          *
 454          * @param string $warning as HTML
 455          * @access private
 456          */
 457         function uploadWarning( $warning ) {
 458                 global $wgOut, $wgUser, $wgLang, $wgUploadDirectory, $wgRequest;
 459                 global $wgUseCopyrightUpload;
 460
 461                 $this->mSessionKey = $this->stashSession();
 462                 if( !$this->mSessionKey ) {
 463                         # Couldn't save file; an error has been displayed so let's go.
 464                         return;
 465                 }
 466
 467                 $sub = wfMsg( 'uploadwarning' );
 468                 $wgOut->addHTML( "<h2>{$sub}</h2>\n" );
 469                 $wgOut->addHTML( "<ul class='warning'>{$warning}</ul><br />\n" );
 470
 471                 $save = wfMsg( 'savefile' );
 472                 $reupload = wfMsg( 'reupload' );
 473                 $iw = wfMsg( 'ignorewarning' );
 474                 $reup = wfMsg( 'reuploaddesc' );
 475                 $titleObj = Title::makeTitle( NS_SPECIAL, 'Upload' );
 476                 $action = $titleObj->escapeLocalURL( 'action=submit' );
 477
 478                 if ( $wgUseCopyrightUpload )
 479                 {
 480                         $copyright =  "
 481         <input type='hidden' name='wpUploadCopyStatus' value=\"" . htmlspecialchars( $this->mUploadCopyStatus ) . "\" />
 482         <input type='hidden' name='wpUploadSource' value=\"" . htmlspecialchars( $this->mUploadSource ) . "\" />
 483         ";
 484                 } else {
 485                         $copyright = "";
 486                 }
 487
 488                 $wgOut->addHTML( "
 489         <form id='uploadwarning' method='post' enctype='multipart/form-data' action='$action'>
 490                 <input type='hidden' name='wpUploadAffirm' value='1' />
 491                 <input type='hidden' name='wpIgnoreWarning' value='1' />
 492                 <input type='hidden' name='wpSessionKey' value=\"" . htmlspecialchars( $this->mSessionKey ) . "\" />
 493                 <input type='hidden' name='wpUploadDescription' value=\"" . htmlspecialchars( $this->mUploadDescription ) . "\" />
 494                 <input type='hidden' name='wpDestFile' value=\"" . htmlspecialchars( $this->mDestFile ) . "\" />
 495         {$copyright}
 496         <table border='0'>
 497                 <tr>
 498                         <tr>
 499                                 <td align='right'>
 500                                         <input tabindex='2' type='submit' name='wpUpload' value='$save' />
 501                                 </td>
 502                                 <td align='left'>$iw</td>
 503                         </tr>
 504                         <tr>
 505                                 <td align='right'>
 506                                         <input tabindex='2' type='submit' name='wpReUpload' value='{$reupload}' />
 507                                 </td>
 508                                 <td align='left'>$reup</td>
 509                         </tr>
 510                 </tr>
 511         </table></form>\n" );
 512         }
 513
 514         /**
 515          * Displays the main upload form, optionally with a highlighted
 516          * error message up at the top.
 517          *
 518          * @param string $msg as HTML
 519          * @access private
 520          */
 521         function mainUploadForm( $msg='' ) {
 522                 global $wgOut, $wgUser, $wgLang, $wgUploadDirectory, $wgRequest;
 523                 global $wgUseCopyrightUpload;
 524
 525                 $cols = intval($wgUser->getOption( 'cols' ));
 526                 $ew = $wgUser->getOption( 'editwidth' );
 527                 if ( $ew ) $ew = " style=\"width:100%\"";
 528                 else $ew = '';
 529
 530                 if ( '' != $msg ) {
 531                         $sub = wfMsg( 'uploaderror' );
 532                         $wgOut->addHTML( "<h2>{$sub}</h2>\n" .
 533                           "<h4 class='error'>{$msg}</h4>\n" );
 534                 } else {
 535                         $sub = wfMsg( 'uploadfile' );
 536                         $wgOut->addHTML( "<h2>{$sub}</h2>\n" );
 537                 }
 538                 $wgOut->addWikiText( wfMsg( 'uploadtext' ) );
 539                 $sk = $wgUser->getSkin();
 540
 541
 542                 $sourcefilename = wfMsg( 'sourcefilename' );
 543                 $destfilename = wfMsg( 'destfilename' );
 544
 545                 $fd = wfMsg( 'filedesc' );
 546                 $ulb = wfMsg( 'uploadbtn' );
 547
 548                 $clink = $sk->makeKnownLink( wfMsgForContent( 'copyrightpage' ),
 549                   wfMsg( 'copyrightpagename' ) );
 550                 $ca = wfMsg( 'affirmation', $clink );
 551                 $iw = wfMsg( 'ignorewarning' );
 552
 553                 $titleObj = Title::makeTitle( NS_SPECIAL, 'Upload' );
 554                 $action = $titleObj->escapeLocalURL();
 555
 556                 $encDestFile = htmlspecialchars( $this->mDestFile );
 557
 558                 $source = "
 559         <td align='right'>
 560         <input tabindex='3' type='checkbox' name='wpUploadAffirm' value='1' id='wpUploadAffirm' />
 561         </td><td align='left'><label for='wpUploadAffirm'>{$ca}</label></td>
 562         " ;
 563                 if ( $wgUseCopyrightUpload )
 564                   {
 565                         $source = "
 566         <td align='right' nowrap='nowrap'>" . wfMsg ( 'filestatus' ) . ":</td>
 567         <td><input tabindex='3' type='text' name=\"wpUploadCopyStatus\" value=\"" .
 568         htmlspecialchars($this->mUploadCopyStatus). "\" size='40' /></td>
 569         </tr><tr>
 570         <td align='right'>". wfMsg ( 'filesource' ) . ":</td>
 571         <td><input tabindex='4' type='text' name='wpUploadSource' value=\"" .
 572         htmlspecialchars($this->mUploadSource). "\" size='40' /></td>
 573         " ;
 574                   }
 575
 576                 $wgOut->addHTML( "
 577         <form id='upload' method='post' enctype='multipart/form-data' action=\"$action\">
 578         <table border='0'><tr>
 579
 580         <td align='right'>{$sourcefilename}:</td><td align='left'>
 581         <input tabindex='1' type='file' name='wpUploadFile' id='wpUploadFile' onchange='fillDestFilename()' size='40' />
 582         </td></tr><tr>
 583
 584         <td align='right'>{$destfilename}:</td><td align='left'>
 585         <input tabindex='1' type='text' name='wpDestFile' id='wpDestFile' size='40' value=\"$encDestFile\" />
 586         </td></tr><tr>
 587
 588         <td align='right'>{$fd}:</td><td align='left'>
 589         <textarea tabindex='2' name='wpUploadDescription' rows='6' cols='{$cols}'{$ew}>"
 590           . htmlspecialchars( $this->mUploadDescription ) .
 591         "</textarea>
 592         </td></tr><tr>
 593         {$source}
 594         </tr>
 595         <tr><td></td><td align='left'>
 596         <input tabindex='5' type='submit' name='wpUpload' value=\"{$ulb}\" />
 597         </td></tr></table></form>\n" );
 598         }
 599
 600         /* -------------------------------------------------------------- */
 601
 602         /**
 603          * Split a file into a base name and all dot-delimited 'extensions'
 604          * on the end. Some web server configurations will fall back to
 605          * earlier pseudo-'extensions' to determine type and execute
 606          * scripts, so the blacklist needs to check them all.
 607          *
 608          * @return array
 609          */
 610         function splitExtensions( $filename ) {
 611                 $bits = explode( '.', $filename );
 612                 $basename = array_shift( $bits );
 613                 return array( $basename, $bits );
 614         }
 615
 616         /**
 617          * Perform case-insensitive match against a list of file extensions.
 618          * Returns true if the extension is in the list.
 619          *
 620          * @param string $ext
 621          * @param array $list
 622          * @return bool
 623          */
 624         function checkFileExtension( $ext, $list ) {
 625                 return in_array( strtolower( $ext ), $list );
 626         }
 627
 628         /**
 629          * Perform case-insensitive match against a list of file extensions.
 630          * Returns true if any of the extensions are in the list.
 631          *
 632          * @param array $ext
 633          * @param array $list
 634          * @return bool
 635          */
 636         function checkFileExtensionList( $ext, $list ) {
 637                 foreach( $ext as $e ) {
 638                         if( in_array( strtolower( $e ), $list ) ) {
 639                                 return true;
 640                         }
 641                 }
 642                 return false;
 643         }
 644
 645         /**
 646          * Returns false if the file is of a known type but can't be recognized,
 647          * indicating a corrupt file.
 648          * Returns true otherwise; unknown file types are not checked if given
 649          * with an unrecognized extension.
 650          *
 651          * @param string $tmpfile Pathname to the temporary upload file
 652          * @param string $extension The filename extension that the file is to be served with
 653          * @return bool
 654          */
 655         function verify( $tmpfile, $extension ) {
 656                 if( $this->triggersIEbug( $tmpfile ) ||
 657                     $this->triggersSafariBug( $tmpfile ) ) {
 658                         return false;
 659                 }
 660
 661                 $fname = 'SpecialUpload::verify';
 662                 $mergeExtensions = array(
 663                         'jpg' => 'jpeg',
 664                         'tif' => 'tiff' );
 665                 $extensionTypes = array(
 666                         # See http://www.php.net/getimagesize
 667                         1 => 'gif',
 668                         2 => 'jpeg',
 669                         3 => 'png',
 670                         4 => 'swf',
 671                         5 => 'psd',
 672                         6 => 'bmp',
 673                         7 => 'tiff',
 674                         8 => 'tiff',
 675                         9 => 'jpc',
 676                         10 => 'jp2',
 677                         11 => 'jpx',
 678                         12 => 'jb2',
 679                         13 => 'swc',
 680                         14 => 'iff',
 681                         15 => 'wbmp',
 682                         16 => 'xbm' );
 683
 684                 $extension = strtolower( $extension );
 685                 if( isset( $mergeExtensions[$extension] ) ) {
 686                         $extension = $mergeExtensions[$extension];
 687                 }
 688                 wfDebug( "$fname: Testing file '$tmpfile' with given extension '$extension'\n" );
 689
 690                 if( !in_array( $extension, $extensionTypes ) ) {
 691                         # Not a recognized image type. We don't know how to verify these.
 692                         # They're allowed by policy or they wouldn't get this far, so we'll
 693                         # let them slide for now.
 694                         wfDebug( "$fname: Unknown extension; passing.\n" );
 695                         return true;
 696                 }
 697
 698                 wfSuppressWarnings();
 699                 $data = getimagesize( $tmpfile );
 700                 wfRestoreWarnings();
 701                 if( false === $data ) {
 702                         # Didn't recognize the image type.
 703                         # Either the image is corrupt or someone's slipping us some
 704                         # bogus data such as HTML+JavaScript trying to take advantage
 705                         # of an Internet Explorer security flaw.
 706                         wfDebug( "$fname: getimagesize() doesn't recognize the file; rejecting.\n" );
 707                         return false;
 708                 }
 709
 710                 $imageType = $data[2];
 711                 if( !isset( $extensionTypes[$imageType] ) ) {
 712                         # Now we're kind of confused. Perhaps new image types added
 713                         # to PHP's support that we don't know about.
 714                         # We'll let these slide for now.
 715                         wfDebug( "$fname: getimagesize() knows the file, but we don't recognize the type; passing.\n" );
 716                         return true;
 717                 }
 718
 719                 $ext = strtolower( $extension );
 720                 if( $extension != $extensionTypes[$imageType] ) {
 721                         # The given filename extension doesn't match the
 722                         # file type. Probably just a mistake, but it's a stupid
 723                         # one and we shouldn't let it pass. KILL THEM!
 724                         wfDebug( "$fname: file extension does not match recognized type; rejecting.\n" );
 725                         return false;
 726                 }
 727
 728                 wfDebug( "$fname: all clear; passing.\n" );
 729                 return true;
 730         }
 731
 732         /**
 733          * Internet Explorer for Windows performs some really stupid file type
 734          * autodetection which can cause it to interpret valid image files as HTML
 735          * and potentially execute JavaScript, creating a cross-site scripting
 736          * attack vectors.
 737          *
 738          * Returns true if IE is likely to mistake the given file for HTML.
 739          *
 740          * @param string $filename
 741          * @return bool
 742          */
 743         function triggersIEbug( $filename ) {
 744                 $file = fopen( $filename, 'rb' );
 745                 $chunk = strtolower( fread( $file, 256 ) );
 746                 fclose( $file );
 747
 748                 $tags = array(
 749                         '<body',
 750                         '<head',
 751                         '<html',
 752                         '<img',
 753                         '<pre',
 754                         '<script',
 755                         '<table',
 756                         '<title' );
 757                 foreach( $tags as $tag ) {
 758                         if( false !== strpos( $chunk, $tag ) ) {
 759                                 return true;
 760                         }
 761                 }
 762                 return false;
 763         }
 764
 765         /**
 766          * Apple's Safari browser performs some unsafe file type autodetection
 767          * which can cause legitimate files to be interpreted as HTML if the
 768          * web server is not correctly configured to send the right content-type
 769          * (or if you're really uploading plain text and octet streams!)
 770          *
 771          * Returns true if Safari would mistake the given file for HTML
 772          * when served with a generic content-type.
 773          *
 774          * @param string $filename
 775          * @return bool
 776          */
 777         function triggersSafariBug( $filename ) {
 778                 $file = fopen( $filename, 'rb' );
 779                 $chunk = strtolower( fread( $file, 1024 ) );
 780                 fclose( $file );
 781
 782                 $tags = array(
 783                         '<html',
 784                         '<script',
 785                         '<title' );
 786                 foreach( $tags as $tag ) {
 787                         if( false !== strpos( $chunk, $tag ) ) {
 788                                 return true;
 789                         }
 790                 }
 791                 return false;
 792         }
 793
 794 }
 795 ?>