includes/upload/UploadBase.php

   1 <?php
   2 /**
   3  * @file
   4  * @ingroup upload
   5  *
   6  * UploadBase and subclasses are the backend of MediaWiki's file uploads.
   7  * The frontends are formed by ApiUpload and SpecialUpload.
   8  *
   9  * See also includes/docs/upload.txt
  10  *
  11  * @author Brion Vibber
  12  * @author Bryan Tong Minh
  13  * @author Michael Dale
  14  */
  15
  16 abstract class UploadBase {
  17         protected $mTempPath;
  18         protected $mDesiredDestName, $mDestName, $mRemoveTempFile, $mSourceType;
  19         protected $mTitle = false, $mTitleError = 0;
  20         protected $mFilteredName, $mFinalExtension;
  21         protected $mLocalFile;
  22
  23         const SUCCESS = 0;
  24         const OK = 0;
  25         const EMPTY_FILE = 3;
  26         const MIN_LENGTH_PARTNAME = 4;
  27         const ILLEGAL_FILENAME = 5;
  28         const OVERWRITE_EXISTING_FILE = 7;
  29         const FILETYPE_MISSING = 8;
  30         const FILETYPE_BADTYPE = 9;
  31         const VERIFICATION_ERROR = 10;
  32
  33         # HOOK_ABORTED is the new name of UPLOAD_VERIFICATION_ERROR
  34         const UPLOAD_VERIFICATION_ERROR = 11;
  35         const HOOK_ABORTED = 11;
  36         const FILE_TOO_LARGE = 12;
  37
  38         const SESSION_VERSION = 2;
  39         const SESSION_KEYNAME = 'wsUploadData';
  40
  41         static public function getSessionKeyname() {
  42                 return self::SESSION_KEYNAME;
  43         }
  44
  45         public function getVerificationErrorCode( $error ) {
  46                 $code_to_status = array(self::EMPTY_FILE => 'empty-file',
  47                                                                 self::FILE_TOO_LARGE => 'file-too-large',
  48                                                                 self::FILETYPE_MISSING => 'filetype-missing',
  49                                                                 self::FILETYPE_BADTYPE => 'filetype-banned',
  50                                                                 self::MIN_LENGTH_PARTNAME => 'filename-tooshort',
  51                                                                 self::ILLEGAL_FILENAME => 'illegal-filename',
  52                                                                 self::OVERWRITE_EXISTING_FILE => 'overwrite',
  53                                                                 self::VERIFICATION_ERROR => 'verification-error',
  54                                                                 self::HOOK_ABORTED =>  'hookaborted',
  55                 );
  56                 if( isset( $code_to_status[$error] ) ) {
  57                         return $code_to_status[$error];
  58                 }
  59
  60                 return 'unknown-error';
  61         }
  62
  63         /**
  64          * Returns true if uploads are enabled.
  65          * Can be override by subclasses.
  66          */
  67         public static function isEnabled() {
  68                 global $wgEnableUploads;
  69                 if ( !$wgEnableUploads ) {
  70                         return false;
  71                 }
  72
  73                 # Check php's file_uploads setting
  74                 if( !wfIniGetBool( 'file_uploads' ) ) {
  75                         return false;
  76                 }
  77                 return true;
  78         }
  79
  80         /**
  81          * Returns an array of permissions that is required to upload a file
  82          *
  83          * @return array
  84          */
  85         public static function getRequiredPermissions() {
  86                 return array( 'upload', 'edit' );
  87         }
  88         /**
  89          * Returns true if the user can use this upload module or else a string
  90          * identifying the missing permission.
  91          * Can be overriden by subclasses.
  92          */
  93         public static function isAllowed( $user ) {
  94                 foreach ( self::getRequiredPermissions() as $permission ) {
  95                         if ( !$user->isAllowed( $permission ) ) {
  96                                 return $permission;
  97                         }
  98                 }
  99                 return true;
 100         }
 101
 102         // Upload handlers. Should probably just be a global.
 103         static $uploadHandlers = array( 'Stash', 'File', 'Url' );
 104
 105         /**
 106          * Create a form of UploadBase depending on wpSourceType and initializes it
 107          */
 108         public static function createFromRequest( &$request, $type = null ) {
 109                 $type = $type ? $type : $request->getVal( 'wpSourceType', 'File' );
 110
 111                 if( !$type ) {
 112                         return null;
 113                 }
 114
 115                 // Get the upload class
 116                 $type = ucfirst( $type );
 117
 118                 // Give hooks the chance to handle this request
 119                 $className = null;
 120                 wfRunHooks( 'UploadCreateFromRequest', array( $type, &$className ) );
 121                 if ( is_null( $className ) ) {
 122                         $className = 'UploadFrom' . $type;
 123                         wfDebug( __METHOD__ . ": class name: $className\n" );
 124                         if( !in_array( $type, self::$uploadHandlers ) ) {
 125                                 return null;
 126                         }
 127                 }
 128
 129                 // Check whether this upload class is enabled
 130                 if( !call_user_func( array( $className, 'isEnabled' ) ) ) {
 131                         return null;
 132                 }
 133
 134                 // Check whether the request is valid
 135                 if( !call_user_func( array( $className, 'isValidRequest' ), $request ) ) {
 136                         return null;
 137                 }
 138
 139                 $handler = new $className;
 140
 141                 $handler->initializeFromRequest( $request );
 142                 return $handler;
 143         }
 144
 145         /**
 146          * Check whether a request if valid for this handler
 147          */
 148         public static function isValidRequest( $request ) {
 149                 return false;
 150         }
 151
 152         public function __construct() {}
 153
 154         /**
 155          * Initialize the path information
 156          * @param $name string the desired destination name
 157          * @param $tempPath string the temporary path
 158          * @param $fileSize int the file size
 159          * @param $removeTempFile bool (false) remove the temporary file?
 160          * @return null
 161          */
 162         public function initializePathInfo( $name, $tempPath, $fileSize, $removeTempFile = false ) {
 163                 $this->mDesiredDestName = $name;
 164                 $this->mTempPath = $tempPath;
 165                 $this->mFileSize = $fileSize;
 166                 $this->mRemoveTempFile = $removeTempFile;
 167         }
 168
 169         /**
 170          * Initialize from a WebRequest. Override this in a subclass.
 171          */
 172         public abstract function initializeFromRequest( &$request );
 173
 174         /**
 175          * Fetch the file. Usually a no-op
 176          */
 177         public function fetchFile() {
 178                 return Status::newGood();
 179         }
 180
 181         /**
 182          * Return true if the file is empty
 183          * @return bool
 184          */
 185         public function isEmptyFile() {
 186                 return empty( $this->mFileSize );
 187         }
 188
 189         /**
 190          * Return the file size
 191          * @return integer
 192          */
 193         public function getFileSize() {
 194                 return $this->mFileSize;
 195         }
 196
 197         /**
 198          * Append a file to the Repo file
 199          *
 200          * @param $srcPath String: path to source file
 201          * @param $toAppendPath String: path to the Repo file that will be appended to.
 202          * @return Status Status
 203          */
 204         protected function appendToUploadFile( $srcPath, $toAppendPath ) {
 205                 $repo = RepoGroup::singleton()->getLocalRepo();
 206                 $status = $repo->append( $srcPath, $toAppendPath );
 207                 return $status;
 208         }
 209
 210         /**
 211          * @param $srcPath String: the source path
 212          * @return the real path if it was a virtual URL
 213          */
 214         function getRealPath( $srcPath ) {
 215                 $repo = RepoGroup::singleton()->getLocalRepo();
 216                 if ( $repo->isVirtualUrl( $srcPath ) ) {
 217                         return $repo->resolveVirtualUrl( $srcPath );
 218                 }
 219                 return $srcPath;
 220         }
 221
 222         /**
 223          * Verify whether the upload is sane.
 224          * @return mixed self::OK or else an array with error information
 225          */
 226         public function verifyUpload( ) {
 227                 /**
 228                  * If there was no filename or a zero size given, give up quick.
 229                  */
 230                 if( $this->isEmptyFile() ) {
 231                         return array( 'status' => self::EMPTY_FILE );
 232                 }
 233
 234                 /**
 235                  * Honor $wgMaxUploadSize
 236                  */
 237                 global $wgMaxUploadSize;
 238                 if( $this->mFileSize > $wgMaxUploadSize ) {
 239                         return array(
 240                                 'status' => self::FILE_TOO_LARGE,
 241                                 'max' => $wgMaxUploadSize,
 242                         );
 243                 }
 244
 245                 /**
 246                  * Look at the contents of the file; if we can recognize the
 247                  * type but it's corrupt or data of the wrong type, we should
 248                  * probably not accept it.
 249                  */
 250                 $verification = $this->verifyFile();
 251                 if( $verification !== true ) {
 252                         return array(
 253                                 'status' => self::VERIFICATION_ERROR,
 254                                 'details' => $verification
 255                         );
 256                 }
 257
 258                 /**
 259                  * Make sure this file can be created
 260                  */
 261                 $result = $this->validateNameAndOverwrite();
 262                 if( $result !== true ) {
 263                         return $result;
 264                 }
 265
 266                 $error = '';
 267                 if( !wfRunHooks( 'UploadVerification',
 268                                 array( $this->mDestName, $this->mTempPath, &$error ) ) ) {
 269                         // @fixme This status needs another name...
 270                         return array( 'status' => self::HOOK_ABORTED, 'error' => $error );
 271                 }
 272
 273                 return array( 'status' => self::OK );
 274         }
 275
 276         /**
 277          * Verify that the name is valid and, if necessary, that we can overwrite
 278          *
 279          * @return mixed true if valid, otherwise and array with 'status'
 280          * and other keys
 281          **/
 282         public function validateNameAndOverwrite() {
 283                 $nt = $this->getTitle();
 284                 if( is_null( $nt ) ) {
 285                         $result = array( 'status' => $this->mTitleError );
 286                         if( $this->mTitleError == self::ILLEGAL_FILENAME ) {
 287                                 $result['filtered'] = $this->mFilteredName;
 288                         }
 289                         if ( $this->mTitleError == self::FILETYPE_BADTYPE ) {
 290                                 $result['finalExt'] = $this->mFinalExtension;
 291                         }
 292                         return $result;
 293                 }
 294                 $this->mDestName = $this->getLocalFile()->getName();
 295
 296                 /**
 297                  * In some cases we may forbid overwriting of existing files.
 298                  */
 299                 $overwrite = $this->checkOverwrite();
 300                 if( $overwrite !== true ) {
 301                         return array(
 302                                 'status' => self::OVERWRITE_EXISTING_FILE,
 303                                 'overwrite' => $overwrite
 304                         );
 305                 }
 306                 return true;
 307         }
 308
 309         /**
 310          * Verify the mime type
 311          * @param $magic MagicMime object
 312          * @param $mime string representing the mime
 313          * @return mixed true if the file is verified, an array otherwise
 314          */
 315         protected function verifyMimeType( $magic, $mime ) {
 316                 global $wgVerifyMimeType;
 317                 if ( $wgVerifyMimeType ) {
 318                         wfDebug ( "\n\nmime: <$mime> extension: <{$this->mFinalExtension}>\n\n");
 319                         if ( !$this->verifyExtension( $mime, $this->mFinalExtension ) ) {
 320                                 return array( 'filetype-mime-mismatch' );
 321                         }
 322
 323                         global $wgMimeTypeBlacklist;
 324                         if ( $this->checkFileExtension( $mime, $wgMimeTypeBlacklist ) ) {
 325                                 return array( 'filetype-badmime', $mime );
 326                         }
 327
 328                         # Check IE type
 329                         $fp = fopen( $this->mTempPath, 'rb' );
 330                         $chunk = fread( $fp, 256 );
 331                         fclose( $fp );
 332                         $extMime = $magic->guessTypesForExtension( $this->mFinalExtension );
 333                         $ieTypes = $magic->getIEMimeTypes( $this->mTempPath, $chunk, $extMime );
 334                         foreach ( $ieTypes as $ieType ) {
 335                                 if ( $this->checkFileExtension( $ieType, $wgMimeTypeBlacklist ) ) {
 336                                         return array( 'filetype-bad-ie-mime', $ieType );
 337                                 }
 338                         }
 339                 }
 340
 341                 return true;
 342         }
 343
 344         /**
 345          * Verifies that it's ok to include the uploaded file
 346          *
 347          * @return mixed true of the file is verified, array otherwise.
 348          */
 349         protected function verifyFile() {
 350                 $this->mFileProps = File::getPropsFromPath( $this->mTempPath, $this->mFinalExtension );
 351                 $this->checkMacBinary();
 352
 353                 # magically determine mime type
 354                 $magic = MimeMagic::singleton();
 355                 $mime = $magic->guessMimeType( $this->mTempPath, false );
 356
 357                 # check mime type, if desired
 358                 $status = $this->verifyMimeType( $magic, $mime );
 359                 if ( $status !== true ) {
 360                         return $status;
 361                 }
 362
 363                 # check for htmlish code and javascript
 364                 if( self::detectScript( $this->mTempPath, $mime, $this->mFinalExtension ) ) {
 365                         return array( 'uploadscripted' );
 366                 }
 367                 if( $this->mFinalExtension == 'svg' || $mime == 'image/svg+xml' ) {
 368                         if( $this->detectScriptInSvg( $this->mTempPath ) ) {
 369                                 return array( 'uploadscripted' );
 370                         }
 371                 }
 372
 373                 /**
 374                 * Scan the uploaded file for viruses
 375                 */
 376                 $virus = $this->detectVirus( $this->mTempPath );
 377                 if ( $virus ) {
 378                         return array( 'uploadvirus', $virus );
 379                 }
 380                 wfDebug( __METHOD__ . ": all clear; passing.\n" );
 381                 return true;
 382         }
 383
 384         /**
 385          * Check whether the user can edit, upload and create the image.
 386          *
 387          * @param $user the User object to verify the permissions against
 388          * @return mixed An array as returned by getUserPermissionsErrors or true
 389          *               in case the user has proper permissions.
 390          */
 391         public function verifyPermissions( $user ) {
 392                 /**
 393                  * If the image is protected, non-sysop users won't be able
 394                  * to modify it by uploading a new revision.
 395                  */
 396                 $nt = $this->getTitle();
 397                 if( is_null( $nt ) ) {
 398                         return true;
 399                 }
 400                 $permErrors = $nt->getUserPermissionsErrors( 'edit', $user );
 401                 $permErrorsUpload = $nt->getUserPermissionsErrors( 'upload', $user );
 402                 if ( $nt->exists() ) {
 403                         $permErrorsCreate = $nt->getUserPermissionsErrors( 'createpage', $user );
 404                 } else {
 405                         $permErrorsCreate = array();
 406                 }
 407                 if( $permErrors || $permErrorsUpload || $permErrorsCreate ) {
 408                         $permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsUpload, $permErrors ) );
 409                         $permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsCreate, $permErrors ) );
 410                         return $permErrors;
 411                 }
 412                 return true;
 413         }
 414
 415         /**
 416          * Check for non fatal problems with the file
 417          *
 418          * @return Array of warnings
 419          */
 420         public function checkWarnings() {
 421                 $warnings = array();
 422
 423                 $localFile = $this->getLocalFile();
 424                 $filename = $localFile->getName();
 425                 $n = strrpos( $filename, '.' );
 426                 $partname = $n ? substr( $filename, 0, $n ) : $filename;
 427
 428                 /**
 429                  * Check whether the resulting filename is different from the desired one,
 430                  * but ignore things like ucfirst() and spaces/underscore things
 431                  */
 432                 $comparableName = str_replace( ' ', '_', $this->mDesiredDestName );
 433                 $comparableName = Title::capitalize( $comparableName, NS_FILE );
 434
 435                 if( $this->mDesiredDestName != $filename && $comparableName != $filename ) {
 436                         $warnings['badfilename'] = $filename;
 437                 }
 438
 439                 // Check whether the file extension is on the unwanted list
 440                 global $wgCheckFileExtensions, $wgFileExtensions;
 441                 if ( $wgCheckFileExtensions ) {
 442                         if ( !$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) ) {
 443                                 $warnings['filetype-unwanted-type'] = $this->mFinalExtension;
 444                         }
 445                 }
 446
 447                 global $wgUploadSizeWarning;
 448                 if ( $wgUploadSizeWarning && ( $this->mFileSize > $wgUploadSizeWarning ) ) {
 449                         $warnings['large-file'] = $wgUploadSizeWarning;
 450                 }
 451
 452                 if ( $this->mFileSize == 0 ) {
 453                         $warnings['emptyfile'] = true;
 454                 }
 455
 456                 $exists = self::getExistsWarning( $localFile );
 457                 if( $exists !== false ) {
 458                         $warnings['exists'] = $exists;
 459                 }
 460
 461                 // Check dupes against existing files
 462                 $hash = File::sha1Base36( $this->mTempPath );
 463                 $dupes = RepoGroup::singleton()->findBySha1( $hash );
 464                 $title = $this->getTitle();
 465                 // Remove all matches against self
 466                 foreach ( $dupes as $key => $dupe ) {
 467                         if( $title->equals( $dupe->getTitle() ) ) {
 468                                 unset( $dupes[$key] );
 469                         }
 470                 }
 471                 if( $dupes ) {
 472                         $warnings['duplicate'] = $dupes;
 473                 }
 474
 475                 // Check dupes against archives
 476                 $archivedImage = new ArchivedFile( null, 0, "{$hash}.{$this->mFinalExtension}" );
 477                 if ( $archivedImage->getID() > 0 ) {
 478                         $warnings['duplicate-archive'] = $archivedImage->getName();
 479                 }
 480
 481                 return $warnings;
 482         }
 483
 484         /**
 485          * Really perform the upload. Stores the file in the local repo, watches
 486          * if necessary and runs the UploadComplete hook.
 487          *
 488          * @return mixed Status indicating the whether the upload succeeded.
 489          */
 490         public function performUpload( $comment, $pageText, $watch, $user ) {
 491                 wfDebug( "\n\n\performUpload: sum: " . $comment . ' c: ' . $pageText .
 492                         ' w: ' . $watch );
 493                 $status = $this->getLocalFile()->upload( $this->mTempPath, $comment, $pageText,
 494                         File::DELETE_SOURCE, $this->mFileProps, false, $user );
 495
 496                 if( $status->isGood() ) {
 497                         if ( $watch ) {
 498                                 $user->addWatch( $this->getLocalFile()->getTitle() );
 499                         }
 500
 501                         wfRunHooks( 'UploadComplete', array( &$this ) );
 502                 }
 503
 504                 return $status;
 505         }
 506
 507         /**
 508          * Returns the title of the file to be uploaded. Sets mTitleError in case
 509          * the name was illegal.
 510          *
 511          * @return Title The title of the file or null in case the name was illegal
 512          */
 513         public function getTitle() {
 514                 if ( $this->mTitle !== false ) {
 515                         return $this->mTitle;
 516                 }
 517
 518                 /**
 519                  * Chop off any directories in the given filename. Then
 520                  * filter out illegal characters, and try to make a legible name
 521                  * out of it. We'll strip some silently that Title would die on.
 522                  */
 523                 $this->mFilteredName = wfStripIllegalFilenameChars( $this->mDesiredDestName );
 524                 /* Normalize to title form before we do any further processing */
 525                 $nt = Title::makeTitleSafe( NS_FILE, $this->mFilteredName );
 526                 if( is_null( $nt ) ) {
 527                         $this->mTitleError = self::ILLEGAL_FILENAME;
 528                         return $this->mTitle = null;
 529                 }
 530                 $this->mFilteredName = $nt->getDBkey();
 531
 532                 /**
 533                  * We'll want to blacklist against *any* 'extension', and use
 534                  * only the final one for the whitelist.
 535                  */
 536                 list( $partname, $ext ) = $this->splitExtensions( $this->mFilteredName );
 537
 538                 if( count( $ext ) ) {
 539                         $this->mFinalExtension = trim( $ext[count( $ext ) - 1] );
 540                 } else {
 541                         $this->mFinalExtension = '';
 542                 }
 543
 544                 /* Don't allow users to override the blacklist (check file extension) */
 545                 global $wgCheckFileExtensions, $wgStrictFileExtensions;
 546                 global $wgFileExtensions, $wgFileBlacklist;
 547                 if ( $this->mFinalExtension == '' ) {
 548                         $this->mTitleError = self::FILETYPE_MISSING;
 549                         return $this->mTitle = null;
 550                 } elseif ( $this->checkFileExtensionList( $ext, $wgFileBlacklist ) ||
 551                                 ( $wgCheckFileExtensions && $wgStrictFileExtensions &&
 552                                         !$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) ) ) {
 553                         $this->mTitleError = self::FILETYPE_BADTYPE;
 554                         return $this->mTitle = null;
 555                 }
 556
 557                 # If there was more than one "extension", reassemble the base
 558                 # filename to prevent bogus complaints about length
 559                 if( count( $ext ) > 1 ) {
 560                         for( $i = 0; $i < count( $ext ) - 1; $i++ ) {
 561                                 $partname .= '.' . $ext[$i];
 562                         }
 563                 }
 564
 565                 if( strlen( $partname ) < 1 ) {
 566                         $this->mTitleError =  self::MIN_LENGTH_PARTNAME;
 567                         return $this->mTitle = null;
 568                 }
 569
 570                 return $this->mTitle = $nt;
 571         }
 572
 573         /**
 574          * Return the local file and initializes if necessary.
 575          */
 576         public function getLocalFile() {
 577                 if( is_null( $this->mLocalFile ) ) {
 578                         $nt = $this->getTitle();
 579                         $this->mLocalFile = is_null( $nt ) ? null : wfLocalFile( $nt );
 580                 }
 581                 return $this->mLocalFile;
 582         }
 583
 584         /**
 585          * Stash a file in a temporary directory for later processing
 586          * after the user has confirmed it.
 587          *
 588          * If the user doesn't explicitly cancel or accept, these files
 589          * can accumulate in the temp directory.
 590          *
 591          * @param $saveName String: the destination filename
 592          * @param $tempSrc String: the source temporary file to save
 593          * @return String: full path the stashed file, or false on failure
 594          */
 595         protected function saveTempUploadedFile( $saveName, $tempSrc ) {
 596                 $repo = RepoGroup::singleton()->getLocalRepo();
 597                 $status = $repo->storeTemp( $saveName, $tempSrc );
 598                 return $status;
 599         }
 600
 601         /**
 602          * Stash a file in a temporary directory for later processing,
 603          * and save the necessary descriptive info into the session.
 604          * Returns a key value which will be passed through a form
 605          * to pick up the path info on a later invocation.
 606          *
 607          * @return Integer: session key
 608          */
 609         public function stashSession( $key = null ) {
 610                 $status = $this->saveTempUploadedFile( $this->mDestName, $this->mTempPath );
 611                 if( !$status->isOK() ) {
 612                         # Couldn't save the file.
 613                         return false;
 614                 }
 615
 616                 if ( is_null( $key ) ) {
 617                         $key = $this->getSessionKey();
 618                 }
 619                 $_SESSION[self::SESSION_KEYNAME][$key] = array(
 620                         'mTempPath'       => $status->value,
 621                         'mFileSize'       => $this->mFileSize,
 622                         'mFileProps'      => $this->mFileProps,
 623                         'version'         => self::SESSION_VERSION,
 624                 );
 625                 return $key;
 626         }
 627
 628         /**
 629          * Generate a random session key from stash in cases where we want
 630          * to start an upload without much information
 631          */
 632         protected function getSessionKey() {
 633                 $key = mt_rand( 0, 0x7fffffff );
 634                 $_SESSION[self::SESSION_KEYNAME][$key] = array();
 635                 return $key;
 636         }
 637
 638         /**
 639          * If we've modified the upload file we need to manually remove it
 640          * on exit to clean up.
 641          */
 642         public function cleanupTempFile() {
 643                 if ( $this->mRemoveTempFile && $this->mTempPath && file_exists( $this->mTempPath ) ) {
 644                         wfDebug( __METHOD__ . ": Removing temporary file {$this->mTempPath}\n" );
 645                         unlink( $this->mTempPath );
 646                 }
 647         }
 648
 649         public function getTempPath() {
 650                 return $this->mTempPath;
 651         }
 652
 653         /**
 654          * Split a file into a base name and all dot-delimited 'extensions'
 655          * on the end. Some web server configurations will fall back to
 656          * earlier pseudo-'extensions' to determine type and execute
 657          * scripts, so the blacklist needs to check them all.
 658          *
 659          * @return array
 660          */
 661         public static function splitExtensions( $filename ) {
 662                 $bits = explode( '.', $filename );
 663                 $basename = array_shift( $bits );
 664                 return array( $basename, $bits );
 665         }
 666
 667         /**
 668          * Perform case-insensitive match against a list of file extensions.
 669          * Returns true if the extension is in the list.
 670          *
 671          * @param $ext String
 672          * @param $list Array
 673          * @return Boolean
 674          */
 675         public static function checkFileExtension( $ext, $list ) {
 676                 return in_array( strtolower( $ext ), $list );
 677         }
 678
 679         /**
 680          * Perform case-insensitive match against a list of file extensions.
 681          * Returns true if any of the extensions are in the list.
 682          *
 683          * @param $ext Array
 684          * @param $list Array
 685          * @return Boolean
 686          */
 687         public static function checkFileExtensionList( $ext, $list ) {
 688                 foreach( $ext as $e ) {
 689                         if( in_array( strtolower( $e ), $list ) ) {
 690                                 return true;
 691                         }
 692                 }
 693                 return false;
 694         }
 695
 696         /**
 697          * Checks if the mime type of the uploaded file matches the file extension.
 698          *
 699          * @param $mime String: the mime type of the uploaded file
 700          * @param $extension String: the filename extension that the file is to be served with
 701          * @return Boolean
 702          */
 703         public static function verifyExtension( $mime, $extension ) {
 704                 $magic = MimeMagic::singleton();
 705
 706                 if ( !$mime || $mime == 'unknown' || $mime == 'unknown/unknown' )
 707                         if ( !$magic->isRecognizableExtension( $extension ) ) {
 708                                 wfDebug( __METHOD__ . ": passing file with unknown detected mime type; " .
 709                                         "unrecognized extension '$extension', can't verify\n" );
 710                                 return true;
 711                         } else {
 712                                 wfDebug( __METHOD__ . ": rejecting file with unknown detected mime type; ".
 713                                         "recognized extension '$extension', so probably invalid file\n" );
 714                                 return false;
 715                         }
 716
 717                 $match = $magic->isMatchingExtension( $extension, $mime );
 718
 719                 if ( $match === null ) {
 720                         wfDebug( __METHOD__ . ": no file extension known for mime type $mime, passing file\n" );
 721                         return true;
 722                 } elseif( $match === true ) {
 723                         wfDebug( __METHOD__ . ": mime type $mime matches extension $extension, passing file\n" );
 724
 725                         #TODO: if it's a bitmap, make sure PHP or ImageMagic resp. can handle it!
 726                         return true;
 727
 728                 } else {
 729                         wfDebug( __METHOD__ . ": mime type $mime mismatches file extension $extension, rejecting file\n" );
 730                         return false;
 731                 }
 732         }
 733
 734         /**
 735          * Heuristic for detecting files that *could* contain JavaScript instructions or
 736          * things that may look like HTML to a browser and are thus
 737          * potentially harmful. The present implementation will produce false
 738          * positives in some situations.
 739          *
 740          * @param $file String: pathname to the temporary upload file
 741          * @param $mime String: the mime type of the file
 742          * @param $extension String: the extension of the file
 743          * @return Boolean: true if the file contains something looking like embedded scripts
 744          */
 745         public static function detectScript( $file, $mime, $extension ) {
 746                 global $wgAllowTitlesInSVG;
 747
 748                 # ugly hack: for text files, always look at the entire file.
 749                 # For binary field, just check the first K.
 750
 751                 if( strpos( $mime,'text/' ) === 0 ) {
 752                         $chunk = file_get_contents( $file );
 753                 } else {
 754                         $fp = fopen( $file, 'rb' );
 755                         $chunk = fread( $fp, 1024 );
 756                         fclose( $fp );
 757                 }
 758
 759                 $chunk = strtolower( $chunk );
 760
 761                 if( !$chunk ) {
 762                         return false;
 763                 }
 764
 765                 # decode from UTF-16 if needed (could be used for obfuscation).
 766                 if( substr( $chunk, 0, 2 ) == "\xfe\xff" ) {
 767                         $enc = 'UTF-16BE';
 768                 } elseif( substr( $chunk, 0, 2 ) == "\xff\xfe" ) {
 769                         $enc = 'UTF-16LE';
 770                 } else {
 771                         $enc = null;
 772                 }
 773
 774                 if( $enc ) {
 775                         $chunk = iconv( $enc, "ASCII//IGNORE", $chunk );
 776                 }
 777
 778                 $chunk = trim( $chunk );
 779
 780                 # FIXME: convert from UTF-16 if necessarry!
 781                 wfDebug( __METHOD__ . ": checking for embedded scripts and HTML stuff\n" );
 782
 783                 # check for HTML doctype
 784                 if ( preg_match( "/<!DOCTYPE *X?HTML/i", $chunk ) ) {
 785                         return true;
 786                 }
 787
 788                 /**
 789                  * Internet Explorer for Windows performs some really stupid file type
 790                  * autodetection which can cause it to interpret valid image files as HTML
 791                  * and potentially execute JavaScript, creating a cross-site scripting
 792                  * attack vectors.
 793                  *
 794                  * Apple's Safari browser also performs some unsafe file type autodetection
 795                  * which can cause legitimate files to be interpreted as HTML if the
 796                  * web server is not correctly configured to send the right content-type
 797                  * (or if you're really uploading plain text and octet streams!)
 798                  *
 799                  * Returns true if IE is likely to mistake the given file for HTML.
 800                  * Also returns true if Safari would mistake the given file for HTML
 801                  * when served with a generic content-type.
 802                  */
 803                 $tags = array(
 804                         '<a href',
 805                         '<body',
 806                         '<head',
 807                         '<html',   #also in safari
 808                         '<img',
 809                         '<pre',
 810                         '<script', #also in safari
 811                         '<table'
 812                 );
 813
 814                 if( !$wgAllowTitlesInSVG && $extension !== 'svg' && $mime !== 'image/svg' ) {
 815                         $tags[] = '<title';
 816                 }
 817
 818                 foreach( $tags as $tag ) {
 819                         if( false !== strpos( $chunk, $tag ) ) {
 820                                 return true;
 821                         }
 822                 }
 823
 824                 /*
 825                  * look for JavaScript
 826                  */
 827
 828                 # resolve entity-refs to look at attributes. may be harsh on big files... cache result?
 829                 $chunk = Sanitizer::decodeCharReferences( $chunk );
 830
 831                 # look for script-types
 832                 if( preg_match( '!type\s*=\s*[\'"]?\s*(?:\w*/)?(?:ecma|java)!sim', $chunk ) ) {
 833                         return true;
 834                 }
 835
 836                 # look for html-style script-urls
 837                 if( preg_match( '!(?:href|src|data)\s*=\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
 838                         return true;
 839                 }
 840
 841                 # look for css-style script-urls
 842                 if( preg_match( '!url\s*\(\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
 843                         return true;
 844                 }
 845
 846                 wfDebug( __METHOD__ . ": no scripts found\n" );
 847                 return false;
 848         }
 849
 850         protected function detectScriptInSvg( $filename ) {
 851                 $check = new XmlTypeCheck( $filename, array( $this, 'checkSvgScriptCallback' ) );
 852                 return $check->filterMatch;
 853         }
 854
 855         /**
 856          * @todo Replace this with a whitelist filter!
 857          */
 858         public function checkSvgScriptCallback( $element, $attribs ) {
 859                 $stripped = $this->stripXmlNamespace( $element );
 860
 861                 if( $stripped == 'script' ) {
 862                         wfDebug( __METHOD__ . ": Found script element '$element' in uploaded file.\n" );
 863                         return true;
 864                 }
 865
 866                 foreach( $attribs as $attrib => $value ) {
 867                         $stripped = $this->stripXmlNamespace( $attrib );
 868                         if( substr( $stripped, 0, 2 ) == 'on' ) {
 869                                 wfDebug( __METHOD__ . ": Found script attribute '$attrib'='value' in uploaded file.\n" );
 870                                 return true;
 871                         }
 872                         if( $stripped == 'href' && strpos( strtolower( $value ), 'javascript:' ) !== false ) {
 873                                 wfDebug( __METHOD__ . ": Found script href attribute '$attrib'='$value' in uploaded file.\n" );
 874                                 return true;
 875                         }
 876                 }
 877         }
 878
 879         private function stripXmlNamespace( $name ) {
 880                 // 'http://www.w3.org/2000/svg:script' -> 'script'
 881                 $parts = explode( ':', strtolower( $name ) );
 882                 return array_pop( $parts );
 883         }
 884
 885         /**
 886          * Generic wrapper function for a virus scanner program.
 887          * This relies on the $wgAntivirus and $wgAntivirusSetup variables.
 888          * $wgAntivirusRequired may be used to deny upload if the scan fails.
 889          *
 890          * @param $file String: pathname to the temporary upload file
 891          * @return mixed false if not virus is found, NULL if the scan fails or is disabled,
 892          *         or a string containing feedback from the virus scanner if a virus was found.
 893          *         If textual feedback is missing but a virus was found, this function returns true.
 894          */
 895         public static function detectVirus( $file ) {
 896                 global $wgAntivirus, $wgAntivirusSetup, $wgAntivirusRequired, $wgOut;
 897
 898                 if ( !$wgAntivirus ) {
 899                         wfDebug( __METHOD__ . ": virus scanner disabled\n" );
 900                         return null;
 901                 }
 902
 903                 if ( !$wgAntivirusSetup[$wgAntivirus] ) {
 904                         wfDebug( __METHOD__ . ": unknown virus scanner: $wgAntivirus\n" );
 905                         $wgOut->wrapWikiMsg( "<div class=\"error\">\n$1\n</div>",
 906                                 array( 'virus-badscanner', $wgAntivirus ) );
 907                         return wfMsg( 'virus-unknownscanner' ) . " $wgAntivirus";
 908                 }
 909
 910                 # look up scanner configuration
 911                 $command = $wgAntivirusSetup[$wgAntivirus]['command'];
 912                 $exitCodeMap = $wgAntivirusSetup[$wgAntivirus]['codemap'];
 913                 $msgPattern = isset( $wgAntivirusSetup[$wgAntivirus]['messagepattern'] ) ?
 914                         $wgAntivirusSetup[$wgAntivirus]['messagepattern'] : null;
 915
 916                 if ( strpos( $command, "%f" ) === false ) {
 917                         # simple pattern: append file to scan
 918                         $command .= " " . wfEscapeShellArg( $file );
 919                 } else {
 920                         # complex pattern: replace "%f" with file to scan
 921                         $command = str_replace( "%f", wfEscapeShellArg( $file ), $command );
 922                 }
 923
 924                 wfDebug( __METHOD__ . ": running virus scan: $command \n" );
 925
 926                 # execute virus scanner
 927                 $exitCode = false;
 928
 929                 # NOTE: there's a 50 line workaround to make stderr redirection work on windows, too.
 930                 #      that does not seem to be worth the pain.
 931                 #      Ask me (Duesentrieb) about it if it's ever needed.
 932                 $output = wfShellExec( "$command 2>&1", $exitCode );
 933
 934                 # map exit code to AV_xxx constants.
 935                 $mappedCode = $exitCode;
 936                 if ( $exitCodeMap ) {
 937                         if ( isset( $exitCodeMap[$exitCode] ) ) {
 938                                 $mappedCode = $exitCodeMap[$exitCode];
 939                         } elseif ( isset( $exitCodeMap["*"] ) ) {
 940                                 $mappedCode = $exitCodeMap["*"];
 941                         }
 942                 }
 943
 944                 if ( $mappedCode === AV_SCAN_FAILED ) {
 945                         # scan failed (code was mapped to false by $exitCodeMap)
 946                         wfDebug( __METHOD__ . ": failed to scan $file (code $exitCode).\n" );
 947
 948                         if ( $wgAntivirusRequired ) {
 949                                 return wfMsg( 'virus-scanfailed', array( $exitCode ) );
 950                         } else {
 951                                 return null;
 952                         }
 953                 } elseif ( $mappedCode === AV_SCAN_ABORTED ) {
 954                         # scan failed because filetype is unknown (probably imune)
 955                         wfDebug( __METHOD__ . ": unsupported file type $file (code $exitCode).\n" );
 956                         return null;
 957                 } elseif ( $mappedCode === AV_NO_VIRUS ) {
 958                         # no virus found
 959                         wfDebug( __METHOD__ . ": file passed virus scan.\n" );
 960                         return false;
 961                 } else {
 962                         $output = trim( $output );
 963
 964                         if ( !$output ) {
 965                                 $output = true; #if there's no output, return true
 966                         } elseif ( $msgPattern ) {
 967                                 $groups = array();
 968                                 if ( preg_match( $msgPattern, $output, $groups ) ) {
 969                                         if ( $groups[1] ) {
 970                                                 $output = $groups[1];
 971                                         }
 972                                 }
 973                         }
 974
 975                         wfDebug( __METHOD__ . ": FOUND VIRUS! scanner feedback: $output \n" );
 976                         return $output;
 977                 }
 978         }
 979
 980         /**
 981          * Check if the temporary file is MacBinary-encoded, as some uploads
 982          * from Internet Explorer on Mac OS Classic and Mac OS X will be.
 983          * If so, the data fork will be extracted to a second temporary file,
 984          * which will then be checked for validity and either kept or discarded.
 985          */
 986         private function checkMacBinary() {
 987                 $macbin = new MacBinary( $this->mTempPath );
 988                 if( $macbin->isValid() ) {
 989                         $dataFile = tempnam( wfTempDir(), 'WikiMacBinary' );
 990                         $dataHandle = fopen( $dataFile, 'wb' );
 991
 992                         wfDebug( __METHOD__ . ": Extracting MacBinary data fork to $dataFile\n" );
 993                         $macbin->extractData( $dataHandle );
 994
 995                         $this->mTempPath = $dataFile;
 996                         $this->mFileSize = $macbin->dataForkLength();
 997
 998                         // We'll have to manually remove the new file if it's not kept.
 999                         $this->mRemoveTempFile = true;
1000                 }
1001                 $macbin->close();
1002         }
1003
1004         /**
1005          * Check if there's an overwrite conflict and, if so, if restrictions
1006          * forbid this user from performing the upload.
1007          *
1008          * @return mixed true on success, error string on failure
1009          */
1010         private function checkOverwrite() {
1011                 global $wgUser;
1012                 // First check whether the local file can be overwritten
1013                 $file = $this->getLocalFile();
1014                 if( $file->exists() ) {
1015                         if( !self::userCanReUpload( $wgUser, $file ) ) {
1016                                 return 'fileexists-forbidden';
1017                         } else {
1018                                 return true;
1019                         }
1020                 }
1021
1022                 /* Check shared conflicts: if the local file does not exist, but
1023                  * wfFindFile finds a file, it exists in a shared repository.
1024                  */
1025                 $file = wfFindFile( $this->getTitle() );
1026                 if ( $file && !$wgUser->isAllowed( 'reupload-shared' ) ) {
1027                         return 'fileexists-shared-forbidden';
1028                 }
1029
1030                 return true;
1031         }
1032
1033         /**
1034          * Check if a user is the last uploader
1035          *
1036          * @param $user User object
1037          * @param $img String: image name
1038          * @return Boolean
1039          */
1040         public static function userCanReUpload( User $user, $img ) {
1041                 if( $user->isAllowed( 'reupload' ) ) {
1042                         return true; // non-conditional
1043                 }
1044                 if( !$user->isAllowed( 'reupload-own' ) ) {
1045                         return false;
1046                 }
1047                 if( is_string( $img ) ) {
1048                         $img = wfLocalFile( $img );
1049                 }
1050                 if ( !( $img instanceof LocalFile ) ) {
1051                         return false;
1052                 }
1053
1054                 return $user->getId() == $img->getUser( 'id' );
1055         }
1056
1057         /**
1058          * Helper function that does various existence checks for a file.
1059          * The following checks are performed:
1060          * - The file exists
1061          * - Article with the same name as the file exists
1062          * - File exists with normalized extension
1063          * - The file looks like a thumbnail and the original exists
1064          *
1065          * @param $file The File object to check
1066          * @return mixed False if the file does not exists, else an array
1067          */
1068         public static function getExistsWarning( $file ) {
1069                 if( $file->exists() ) {
1070                         return array( 'warning' => 'exists', 'file' => $file );
1071                 }
1072
1073                 if( $file->getTitle()->getArticleID() ) {
1074                         return array( 'warning' => 'page-exists', 'file' => $file );
1075                 }
1076
1077                 if ( $file->wasDeleted() && !$file->exists() ) {
1078                         return array( 'warning' => 'was-deleted', 'file' => $file );
1079                 }
1080
1081                 if( strpos( $file->getName(), '.' ) == false ) {
1082                         $partname = $file->getName();
1083                         $extension = '';
1084                 } else {
1085                         $n = strrpos( $file->getName(), '.' );
1086                         $extension = substr( $file->getName(), $n + 1 );
1087                         $partname = substr( $file->getName(), 0, $n );
1088                 }
1089                 $normalizedExtension = File::normalizeExtension( $extension );
1090
1091                 if ( $normalizedExtension != $extension ) {
1092                         // We're not using the normalized form of the extension.
1093                         // Normal form is lowercase, using most common of alternate
1094                         // extensions (eg 'jpg' rather than 'JPEG').
1095                         //
1096                         // Check for another file using the normalized form...
1097                         $nt_lc = Title::makeTitle( NS_FILE, "{$partname}.{$normalizedExtension}" );
1098                         $file_lc = wfLocalFile( $nt_lc );
1099
1100                         if( $file_lc->exists() ) {
1101                                 return array(
1102                                         'warning' => 'exists-normalized',
1103                                         'file' => $file,
1104                                         'normalizedFile' => $file_lc
1105                                 );
1106                         }
1107                 }
1108
1109                 if ( self::isThumbName( $file->getName() ) ) {
1110                         # Check for filenames like 50px- or 180px-, these are mostly thumbnails
1111                         $nt_thb = Title::newFromText( substr( $partname , strpos( $partname , '-' ) +1 ) . '.' . $extension, NS_FILE );
1112                         $file_thb = wfLocalFile( $nt_thb );
1113                         if( $file_thb->exists() ) {
1114                                 return array(
1115                                         'warning' => 'thumb',
1116                                         'file' => $file,
1117                                         'thumbFile' => $file_thb
1118                                 );
1119                         } else {
1120                                 // File does not exist, but we just don't like the name
1121                                 return array(
1122                                         'warning' => 'thumb-name',
1123                                         'file' => $file,
1124                                         'thumbFile' => $file_thb
1125                                 );
1126                         }
1127                 }
1128
1129
1130                 foreach( self::getFilenamePrefixBlacklist() as $prefix ) {
1131                         if ( substr( $partname, 0, strlen( $prefix ) ) == $prefix ) {
1132                                 return array(
1133                                         'warning' => 'bad-prefix',
1134                                         'file' => $file,
1135                                         'prefix' => $prefix
1136                                 );
1137                         }
1138                 }
1139
1140                 return false;
1141         }
1142
1143         /**
1144          * Helper function that checks whether the filename looks like a thumbnail
1145          */
1146         public static function isThumbName( $filename ) {
1147                 $n = strrpos( $filename, '.' );
1148                 $partname = $n ? substr( $filename, 0, $n ) : $filename;
1149                 return (
1150                                         substr( $partname , 3, 3 ) == 'px-' ||
1151                                         substr( $partname , 2, 3 ) == 'px-'
1152                                 ) &&
1153                                 preg_match( "/[0-9]{2}/" , substr( $partname , 0, 2 ) );
1154         }
1155
1156         /**
1157          * Get a list of blacklisted filename prefixes from [[MediaWiki:Filename-prefix-blacklist]]
1158          *
1159          * @return array list of prefixes
1160          */
1161         public static function getFilenamePrefixBlacklist() {
1162                 $blacklist = array();
1163                 $message = wfMsgForContent( 'filename-prefix-blacklist' );
1164                 if( $message && !( wfEmptyMsg( 'filename-prefix-blacklist', $message ) || $message == '-' ) ) {
1165                         $lines = explode( "\n", $message );
1166                         foreach( $lines as $line ) {
1167                                 // Remove comment lines
1168                                 $comment = substr( trim( $line ), 0, 1 );
1169                                 if ( $comment == '#' || $comment == '' ) {
1170                                         continue;
1171                                 }
1172                                 // Remove additional comments after a prefix
1173                                 $comment = strpos( $line, '#' );
1174                                 if ( $comment > 0 ) {
1175                                         $line = substr( $line, 0, $comment-1 );
1176                                 }
1177                                 $blacklist[] = trim( $line );
1178                         }
1179                 }
1180                 return $blacklist;
1181         }
1182
1183         public function getImageInfo( $result ) {
1184                 $file = $this->getLocalFile();
1185                 $imParam = ApiQueryImageInfo::getPropertyNames();
1186                 return ApiQueryImageInfo::getInfo( $file, array_flip( $imParam ), $result );
1187         }
1188
1189         public function convertVerifyErrorToStatus( $error ) {
1190                 $args = func_get_args();
1191                 array_shift($args);
1192                 return Status::newFatal( $this->getVerificationErrorCode( $error ), $args );
1193         }
1194 }