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; # Not used anymore; handled by verifyPermissions()
  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->validateName();
 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         protected function validateName() {
 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                 return true;
 297         }
 298
 299         /**
 300          * Verify the mime type
 301          * @param $magic MagicMime object
 302          * @param $mime string representing the mime
 303          * @return mixed true if the file is verified, an array otherwise
 304          */
 305         protected function verifyMimeType( $magic, $mime ) {
 306                 global $wgVerifyMimeType;
 307                 if ( $wgVerifyMimeType ) {
 308                         wfDebug ( "\n\nmime: <$mime> extension: <{$this->mFinalExtension}>\n\n");
 309                         if ( !$this->verifyExtension( $mime, $this->mFinalExtension ) ) {
 310                                 return array( 'filetype-mime-mismatch' );
 311                         }
 312
 313                         global $wgMimeTypeBlacklist;
 314                         if ( $this->checkFileExtension( $mime, $wgMimeTypeBlacklist ) ) {
 315                                 return array( 'filetype-badmime', $mime );
 316                         }
 317
 318                         # Check IE type
 319                         $fp = fopen( $this->mTempPath, 'rb' );
 320                         $chunk = fread( $fp, 256 );
 321                         fclose( $fp );
 322                         $extMime = $magic->guessTypesForExtension( $this->mFinalExtension );
 323                         $ieTypes = $magic->getIEMimeTypes( $this->mTempPath, $chunk, $extMime );
 324                         foreach ( $ieTypes as $ieType ) {
 325                                 if ( $this->checkFileExtension( $ieType, $wgMimeTypeBlacklist ) ) {
 326                                         return array( 'filetype-bad-ie-mime', $ieType );
 327                                 }
 328                         }
 329                 }
 330
 331                 return true;
 332         }
 333
 334         /**
 335          * Verifies that it's ok to include the uploaded file
 336          *
 337          * @return mixed true of the file is verified, array otherwise.
 338          */
 339         protected function verifyFile() {
 340                 # get the title, even though we are doing nothing with it, because
 341                 # we need to populate mFinalExtension
 342                 $nt = $this->getTitle();
 343
 344                 $this->mFileProps = File::getPropsFromPath( $this->mTempPath, $this->mFinalExtension );
 345                 $this->checkMacBinary();
 346
 347                 # magically determine mime type
 348                 $magic = MimeMagic::singleton();
 349                 $mime = $magic->guessMimeType( $this->mTempPath, false );
 350
 351                 # check mime type, if desired
 352                 $status = $this->verifyMimeType( $magic, $mime );
 353                 if ( $status !== true ) {
 354                         return $status;
 355                 }
 356
 357                 # check for htmlish code and javascript
 358                 if( self::detectScript( $this->mTempPath, $mime, $this->mFinalExtension ) ) {
 359                         return array( 'uploadscripted' );
 360                 }
 361                 if( $this->mFinalExtension == 'svg' || $mime == 'image/svg+xml' ) {
 362                         if( $this->detectScriptInSvg( $this->mTempPath ) ) {
 363                                 return array( 'uploadscripted' );
 364                         }
 365                 }
 366
 367                 /**
 368                 * Scan the uploaded file for viruses
 369                 */
 370                 $virus = $this->detectVirus( $this->mTempPath );
 371                 if ( $virus ) {
 372                         return array( 'uploadvirus', $virus );
 373                 }
 374                 wfDebug( __METHOD__ . ": all clear; passing.\n" );
 375                 return true;
 376         }
 377
 378         /**
 379          * Check whether the user can edit, upload and create the image. This
 380          * checks only against the current title; if it returns errors, it may
 381          * very well be that another title will not give errors. Therefore
 382          * isAllowed() should be called as well for generic is-user-blocked or
 383          * can-user-upload checking.
 384          *
 385          * @param $user the User object to verify the permissions against
 386          * @return mixed An array as returned by getUserPermissionsErrors or true
 387          *               in case the user has proper permissions.
 388          */
 389         public function verifyPermissions( $user ) {
 390                 /**
 391                  * If the image is protected, non-sysop users won't be able
 392                  * to modify it by uploading a new revision.
 393                  */
 394                 $nt = $this->getTitle();
 395                 if( is_null( $nt ) ) {
 396                         return true;
 397                 }
 398                 $permErrors = $nt->getUserPermissionsErrors( 'edit', $user );
 399                 $permErrorsUpload = $nt->getUserPermissionsErrors( 'upload', $user );
 400                 if ( $nt->exists() ) {
 401                         $permErrorsCreate = $nt->getUserPermissionsErrors( 'createpage', $user );
 402                 } else {
 403                         $permErrorsCreate = array();
 404                 }
 405                 if( $permErrors || $permErrorsUpload || $permErrorsCreate ) {
 406                         $permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsUpload, $permErrors ) );
 407                         $permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsCreate, $permErrors ) );
 408                         return $permErrors;
 409                 }
 410
 411                 $overwriteError = $this->checkOverwrite( $user );
 412                 if ( $overwriteError !== true ) {
 413                         return array( array( $overwriteError ) );
 414                 }
 415
 416                 return true;
 417         }
 418
 419         /**
 420          * Check for non fatal problems with the file
 421          *
 422          * @return Array of warnings
 423          */
 424         public function checkWarnings() {
 425                 $warnings = array();
 426
 427                 $localFile = $this->getLocalFile();
 428                 $filename = $localFile->getName();
 429                 $n = strrpos( $filename, '.' );
 430                 $partname = $n ? substr( $filename, 0, $n ) : $filename;
 431
 432                 /**
 433                  * Check whether the resulting filename is different from the desired one,
 434                  * but ignore things like ucfirst() and spaces/underscore things
 435                  */
 436                 $comparableName = str_replace( ' ', '_', $this->mDesiredDestName );
 437                 $comparableName = Title::capitalize( $comparableName, NS_FILE );
 438
 439                 if( $this->mDesiredDestName != $filename && $comparableName != $filename ) {
 440                         $warnings['badfilename'] = $filename;
 441                 }
 442
 443                 // Check whether the file extension is on the unwanted list
 444                 global $wgCheckFileExtensions, $wgFileExtensions;
 445                 if ( $wgCheckFileExtensions ) {
 446                         if ( !$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) ) {
 447                                 $warnings['filetype-unwanted-type'] = $this->mFinalExtension;
 448                         }
 449                 }
 450
 451                 global $wgUploadSizeWarning;
 452                 if ( $wgUploadSizeWarning && ( $this->mFileSize > $wgUploadSizeWarning ) ) {
 453                         $warnings['large-file'] = $wgUploadSizeWarning;
 454                 }
 455
 456                 if ( $this->mFileSize == 0 ) {
 457                         $warnings['emptyfile'] = true;
 458                 }
 459
 460                 $exists = self::getExistsWarning( $localFile );
 461                 if( $exists !== false ) {
 462                         $warnings['exists'] = $exists;
 463                 }
 464
 465                 // Check dupes against existing files
 466                 $hash = File::sha1Base36( $this->mTempPath );
 467                 $dupes = RepoGroup::singleton()->findBySha1( $hash );
 468                 $title = $this->getTitle();
 469                 // Remove all matches against self
 470                 foreach ( $dupes as $key => $dupe ) {
 471                         if( $title->equals( $dupe->getTitle() ) ) {
 472                                 unset( $dupes[$key] );
 473                         }
 474                 }
 475                 if( $dupes ) {
 476                         $warnings['duplicate'] = $dupes;
 477                 }
 478
 479                 // Check dupes against archives
 480                 $archivedImage = new ArchivedFile( null, 0, "{$hash}.{$this->mFinalExtension}" );
 481                 if ( $archivedImage->getID() > 0 ) {
 482                         $warnings['duplicate-archive'] = $archivedImage->getName();
 483                 }
 484
 485                 return $warnings;
 486         }
 487
 488         /**
 489          * Really perform the upload. Stores the file in the local repo, watches
 490          * if necessary and runs the UploadComplete hook.
 491          *
 492          * @return mixed Status indicating the whether the upload succeeded.
 493          */
 494         public function performUpload( $comment, $pageText, $watch, $user ) {
 495                 wfDebug( "\n\n\performUpload: sum: " . $comment . ' c: ' . $pageText .
 496                         ' w: ' . $watch );
 497                 $status = $this->getLocalFile()->upload( $this->mTempPath, $comment, $pageText,
 498                         File::DELETE_SOURCE, $this->mFileProps, false, $user );
 499
 500                 if( $status->isGood() ) {
 501                         if ( $watch ) {
 502                                 $user->addWatch( $this->getLocalFile()->getTitle() );
 503                         }
 504
 505                         wfRunHooks( 'UploadComplete', array( &$this ) );
 506                 }
 507
 508                 return $status;
 509         }
 510
 511         /**
 512          * Returns the title of the file to be uploaded. Sets mTitleError in case
 513          * the name was illegal.
 514          *
 515          * @return Title The title of the file or null in case the name was illegal
 516          */
 517         public function getTitle() {
 518                 if ( $this->mTitle !== false ) {
 519                         return $this->mTitle;
 520                 }
 521
 522                 /**
 523                  * Chop off any directories in the given filename. Then
 524                  * filter out illegal characters, and try to make a legible name
 525                  * out of it. We'll strip some silently that Title would die on.
 526                  */
 527                 $this->mFilteredName = wfStripIllegalFilenameChars( $this->mDesiredDestName );
 528                 /* Normalize to title form before we do any further processing */
 529                 $nt = Title::makeTitleSafe( NS_FILE, $this->mFilteredName );
 530                 if( is_null( $nt ) ) {
 531                         $this->mTitleError = self::ILLEGAL_FILENAME;
 532                         return $this->mTitle = null;
 533                 }
 534                 $this->mFilteredName = $nt->getDBkey();
 535
 536                 /**
 537                  * We'll want to blacklist against *any* 'extension', and use
 538                  * only the final one for the whitelist.
 539                  */
 540                 list( $partname, $ext ) = $this->splitExtensions( $this->mFilteredName );
 541
 542                 if( count( $ext ) ) {
 543                         $this->mFinalExtension = trim( $ext[count( $ext ) - 1] );
 544                 } else {
 545                         $this->mFinalExtension = '';
 546                 }
 547
 548                 /* Don't allow users to override the blacklist (check file extension) */
 549                 global $wgCheckFileExtensions, $wgStrictFileExtensions;
 550                 global $wgFileExtensions, $wgFileBlacklist;
 551                 if ( $this->mFinalExtension == '' ) {
 552                         $this->mTitleError = self::FILETYPE_MISSING;
 553                         return $this->mTitle = null;
 554                 } elseif ( $this->checkFileExtensionList( $ext, $wgFileBlacklist ) ||
 555                                 ( $wgCheckFileExtensions && $wgStrictFileExtensions &&
 556                                         !$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) ) ) {
 557                         $this->mTitleError = self::FILETYPE_BADTYPE;
 558                         return $this->mTitle = null;
 559                 }
 560
 561                 # If there was more than one "extension", reassemble the base
 562                 # filename to prevent bogus complaints about length
 563                 if( count( $ext ) > 1 ) {
 564                         for( $i = 0; $i < count( $ext ) - 1; $i++ ) {
 565                                 $partname .= '.' . $ext[$i];
 566                         }
 567                 }
 568
 569                 if( strlen( $partname ) < 1 ) {
 570                         $this->mTitleError =  self::MIN_LENGTH_PARTNAME;
 571                         return $this->mTitle = null;
 572                 }
 573
 574                 return $this->mTitle = $nt;
 575         }
 576
 577         /**
 578          * Return the local file and initializes if necessary.
 579          */
 580         public function getLocalFile() {
 581                 if( is_null( $this->mLocalFile ) ) {
 582                         $nt = $this->getTitle();
 583                         $this->mLocalFile = is_null( $nt ) ? null : wfLocalFile( $nt );
 584                 }
 585                 return $this->mLocalFile;
 586         }
 587
 588         /**
 589          * Stash a file in a temporary directory for later processing
 590          * after the user has confirmed it.
 591          *
 592          * If the user doesn't explicitly cancel or accept, these files
 593          * can accumulate in the temp directory.
 594          *
 595          * @param $saveName String: the destination filename
 596          * @param $tempSrc String: the source temporary file to save
 597          * @return String: full path the stashed file, or false on failure
 598          */
 599         protected function saveTempUploadedFile( $saveName, $tempSrc ) {
 600                 $repo = RepoGroup::singleton()->getLocalRepo();
 601                 $status = $repo->storeTemp( $saveName, $tempSrc );
 602                 return $status;
 603         }
 604
 605         /**
 606          * Stash a file in a temporary directory for later processing,
 607          * and save the necessary descriptive info into the session.
 608          * Returns a key value which will be passed through a form
 609          * to pick up the path info on a later invocation.
 610          *
 611          * @return Integer: session key
 612          */
 613         public function stashSession( $key = null ) {
 614                 $status = $this->saveTempUploadedFile( $this->mDestName, $this->mTempPath );
 615                 if( !$status->isOK() ) {
 616                         # Couldn't save the file.
 617                         return false;
 618                 }
 619
 620                 if ( is_null( $key ) ) {
 621                         $key = $this->getSessionKey();
 622                 }
 623                 $_SESSION[self::SESSION_KEYNAME][$key] = array(
 624                         'mTempPath'       => $status->value,
 625                         'mFileSize'       => $this->mFileSize,
 626                         'mFileProps'      => $this->mFileProps,
 627                         'version'         => self::SESSION_VERSION,
 628                 );
 629                 return $key;
 630         }
 631
 632         /**
 633          * Generate a random session key from stash in cases where we want
 634          * to start an upload without much information
 635          */
 636         protected function getSessionKey() {
 637                 $key = mt_rand( 0, 0x7fffffff );
 638                 $_SESSION[self::SESSION_KEYNAME][$key] = array();
 639                 return $key;
 640         }
 641
 642         /**
 643          * If we've modified the upload file we need to manually remove it
 644          * on exit to clean up.
 645          */
 646         public function cleanupTempFile() {
 647                 if ( $this->mRemoveTempFile && $this->mTempPath && file_exists( $this->mTempPath ) ) {
 648                         wfDebug( __METHOD__ . ": Removing temporary file {$this->mTempPath}\n" );
 649                         unlink( $this->mTempPath );
 650                 }
 651         }
 652
 653         public function getTempPath() {
 654                 return $this->mTempPath;
 655         }
 656
 657         /**
 658          * Split a file into a base name and all dot-delimited 'extensions'
 659          * on the end. Some web server configurations will fall back to
 660          * earlier pseudo-'extensions' to determine type and execute
 661          * scripts, so the blacklist needs to check them all.
 662          *
 663          * @return array
 664          */
 665         public static function splitExtensions( $filename ) {
 666                 $bits = explode( '.', $filename );
 667                 $basename = array_shift( $bits );
 668                 return array( $basename, $bits );
 669         }
 670
 671         /**
 672          * Perform case-insensitive match against a list of file extensions.
 673          * Returns true if the extension is in the list.
 674          *
 675          * @param $ext String
 676          * @param $list Array
 677          * @return Boolean
 678          */
 679         public static function checkFileExtension( $ext, $list ) {
 680                 return in_array( strtolower( $ext ), $list );
 681         }
 682
 683         /**
 684          * Perform case-insensitive match against a list of file extensions.
 685          * Returns true if any of the extensions are in the list.
 686          *
 687          * @param $ext Array
 688          * @param $list Array
 689          * @return Boolean
 690          */
 691         public static function checkFileExtensionList( $ext, $list ) {
 692                 foreach( $ext as $e ) {
 693                         if( in_array( strtolower( $e ), $list ) ) {
 694                                 return true;
 695                         }
 696                 }
 697                 return false;
 698         }
 699
 700         /**
 701          * Checks if the mime type of the uploaded file matches the file extension.
 702          *
 703          * @param $mime String: the mime type of the uploaded file
 704          * @param $extension String: the filename extension that the file is to be served with
 705          * @return Boolean
 706          */
 707         public static function verifyExtension( $mime, $extension ) {
 708                 $magic = MimeMagic::singleton();
 709
 710                 if ( !$mime || $mime == 'unknown' || $mime == 'unknown/unknown' )
 711                         if ( !$magic->isRecognizableExtension( $extension ) ) {
 712                                 wfDebug( __METHOD__ . ": passing file with unknown detected mime type; " .
 713                                         "unrecognized extension '$extension', can't verify\n" );
 714                                 return true;
 715                         } else {
 716                                 wfDebug( __METHOD__ . ": rejecting file with unknown detected mime type; ".
 717                                         "recognized extension '$extension', so probably invalid file\n" );
 718                                 return false;
 719                         }
 720
 721                 $match = $magic->isMatchingExtension( $extension, $mime );
 722
 723                 if ( $match === null ) {
 724                         wfDebug( __METHOD__ . ": no file extension known for mime type $mime, passing file\n" );
 725                         return true;
 726                 } elseif( $match === true ) {
 727                         wfDebug( __METHOD__ . ": mime type $mime matches extension $extension, passing file\n" );
 728
 729                         #TODO: if it's a bitmap, make sure PHP or ImageMagic resp. can handle it!
 730                         return true;
 731
 732                 } else {
 733                         wfDebug( __METHOD__ . ": mime type $mime mismatches file extension $extension, rejecting file\n" );
 734                         return false;
 735                 }
 736         }
 737
 738         /**
 739          * Heuristic for detecting files that *could* contain JavaScript instructions or
 740          * things that may look like HTML to a browser and are thus
 741          * potentially harmful. The present implementation will produce false
 742          * positives in some situations.
 743          *
 744          * @param $file String: pathname to the temporary upload file
 745          * @param $mime String: the mime type of the file
 746          * @param $extension String: the extension of the file
 747          * @return Boolean: true if the file contains something looking like embedded scripts
 748          */
 749         public static function detectScript( $file, $mime, $extension ) {
 750                 global $wgAllowTitlesInSVG;
 751
 752                 # ugly hack: for text files, always look at the entire file.
 753                 # For binary field, just check the first K.
 754
 755                 if( strpos( $mime,'text/' ) === 0 ) {
 756                         $chunk = file_get_contents( $file );
 757                 } else {
 758                         $fp = fopen( $file, 'rb' );
 759                         $chunk = fread( $fp, 1024 );
 760                         fclose( $fp );
 761                 }
 762
 763                 $chunk = strtolower( $chunk );
 764
 765                 if( !$chunk ) {
 766                         return false;
 767                 }
 768
 769                 # decode from UTF-16 if needed (could be used for obfuscation).
 770                 if( substr( $chunk, 0, 2 ) == "\xfe\xff" ) {
 771                         $enc = 'UTF-16BE';
 772                 } elseif( substr( $chunk, 0, 2 ) == "\xff\xfe" ) {
 773                         $enc = 'UTF-16LE';
 774                 } else {
 775                         $enc = null;
 776                 }
 777
 778                 if( $enc ) {
 779                         $chunk = iconv( $enc, "ASCII//IGNORE", $chunk );
 780                 }
 781
 782                 $chunk = trim( $chunk );
 783
 784                 # FIXME: convert from UTF-16 if necessarry!
 785                 wfDebug( __METHOD__ . ": checking for embedded scripts and HTML stuff\n" );
 786
 787                 # check for HTML doctype
 788                 if ( preg_match( "/<!DOCTYPE *X?HTML/i", $chunk ) ) {
 789                         return true;
 790                 }
 791
 792                 /**
 793                  * Internet Explorer for Windows performs some really stupid file type
 794                  * autodetection which can cause it to interpret valid image files as HTML
 795                  * and potentially execute JavaScript, creating a cross-site scripting
 796                  * attack vectors.
 797                  *
 798                  * Apple's Safari browser also performs some unsafe file type autodetection
 799                  * which can cause legitimate files to be interpreted as HTML if the
 800                  * web server is not correctly configured to send the right content-type
 801                  * (or if you're really uploading plain text and octet streams!)
 802                  *
 803                  * Returns true if IE is likely to mistake the given file for HTML.
 804                  * Also returns true if Safari would mistake the given file for HTML
 805                  * when served with a generic content-type.
 806                  */
 807                 $tags = array(
 808                         '<a href',
 809                         '<body',
 810                         '<head',
 811                         '<html',   #also in safari
 812                         '<img',
 813                         '<pre',
 814                         '<script', #also in safari
 815                         '<table'
 816                 );
 817
 818                 if( !$wgAllowTitlesInSVG && $extension !== 'svg' && $mime !== 'image/svg' ) {
 819                         $tags[] = '<title';
 820                 }
 821
 822                 foreach( $tags as $tag ) {
 823                         if( false !== strpos( $chunk, $tag ) ) {
 824                                 return true;
 825                         }
 826                 }
 827
 828                 /*
 829                  * look for JavaScript
 830                  */
 831
 832                 # resolve entity-refs to look at attributes. may be harsh on big files... cache result?
 833                 $chunk = Sanitizer::decodeCharReferences( $chunk );
 834
 835                 # look for script-types
 836                 if( preg_match( '!type\s*=\s*[\'"]?\s*(?:\w*/)?(?:ecma|java)!sim', $chunk ) ) {
 837                         return true;
 838                 }
 839
 840                 # look for html-style script-urls
 841                 if( preg_match( '!(?:href|src|data)\s*=\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
 842                         return true;
 843                 }
 844
 845                 # look for css-style script-urls
 846                 if( preg_match( '!url\s*\(\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
 847                         return true;
 848                 }
 849
 850                 wfDebug( __METHOD__ . ": no scripts found\n" );
 851                 return false;
 852         }
 853
 854         protected function detectScriptInSvg( $filename ) {
 855                 $check = new XmlTypeCheck( $filename, array( $this, 'checkSvgScriptCallback' ) );
 856                 return $check->filterMatch;
 857         }
 858
 859         /**
 860          * @todo Replace this with a whitelist filter!
 861          */
 862         public function checkSvgScriptCallback( $element, $attribs ) {
 863                 $stripped = $this->stripXmlNamespace( $element );
 864
 865                 if( $stripped == 'script' ) {
 866                         wfDebug( __METHOD__ . ": Found script element '$element' in uploaded file.\n" );
 867                         return true;
 868                 }
 869
 870                 foreach( $attribs as $attrib => $value ) {
 871                         $stripped = $this->stripXmlNamespace( $attrib );
 872                         if( substr( $stripped, 0, 2 ) == 'on' ) {
 873                                 wfDebug( __METHOD__ . ": Found script attribute '$attrib'='value' in uploaded file.\n" );
 874                                 return true;
 875                         }
 876                         if( $stripped == 'href' && strpos( strtolower( $value ), 'javascript:' ) !== false ) {
 877                                 wfDebug( __METHOD__ . ": Found script href attribute '$attrib'='$value' in uploaded file.\n" );
 878                                 return true;
 879                         }
 880                 }
 881         }
 882
 883         private function stripXmlNamespace( $name ) {
 884                 // 'http://www.w3.org/2000/svg:script' -> 'script'
 885                 $parts = explode( ':', strtolower( $name ) );
 886                 return array_pop( $parts );
 887         }
 888
 889         /**
 890          * Generic wrapper function for a virus scanner program.
 891          * This relies on the $wgAntivirus and $wgAntivirusSetup variables.
 892          * $wgAntivirusRequired may be used to deny upload if the scan fails.
 893          *
 894          * @param $file String: pathname to the temporary upload file
 895          * @return mixed false if not virus is found, NULL if the scan fails or is disabled,
 896          *         or a string containing feedback from the virus scanner if a virus was found.
 897          *         If textual feedback is missing but a virus was found, this function returns true.
 898          */
 899         public static function detectVirus( $file ) {
 900                 global $wgAntivirus, $wgAntivirusSetup, $wgAntivirusRequired, $wgOut;
 901
 902                 if ( !$wgAntivirus ) {
 903                         wfDebug( __METHOD__ . ": virus scanner disabled\n" );
 904                         return null;
 905                 }
 906
 907                 if ( !$wgAntivirusSetup[$wgAntivirus] ) {
 908                         wfDebug( __METHOD__ . ": unknown virus scanner: $wgAntivirus\n" );
 909                         $wgOut->wrapWikiMsg( "<div class=\"error\">\n$1\n</div>",
 910                                 array( 'virus-badscanner', $wgAntivirus ) );
 911                         return wfMsg( 'virus-unknownscanner' ) . " $wgAntivirus";
 912                 }
 913
 914                 # look up scanner configuration
 915                 $command = $wgAntivirusSetup[$wgAntivirus]['command'];
 916                 $exitCodeMap = $wgAntivirusSetup[$wgAntivirus]['codemap'];
 917                 $msgPattern = isset( $wgAntivirusSetup[$wgAntivirus]['messagepattern'] ) ?
 918                         $wgAntivirusSetup[$wgAntivirus]['messagepattern'] : null;
 919
 920                 if ( strpos( $command, "%f" ) === false ) {
 921                         # simple pattern: append file to scan
 922                         $command .= " " . wfEscapeShellArg( $file );
 923                 } else {
 924                         # complex pattern: replace "%f" with file to scan
 925                         $command = str_replace( "%f", wfEscapeShellArg( $file ), $command );
 926                 }
 927
 928                 wfDebug( __METHOD__ . ": running virus scan: $command \n" );
 929
 930                 # execute virus scanner
 931                 $exitCode = false;
 932
 933                 # NOTE: there's a 50 line workaround to make stderr redirection work on windows, too.
 934                 #      that does not seem to be worth the pain.
 935                 #      Ask me (Duesentrieb) about it if it's ever needed.
 936                 $output = wfShellExec( "$command 2>&1", $exitCode );
 937
 938                 # map exit code to AV_xxx constants.
 939                 $mappedCode = $exitCode;
 940                 if ( $exitCodeMap ) {
 941                         if ( isset( $exitCodeMap[$exitCode] ) ) {
 942                                 $mappedCode = $exitCodeMap[$exitCode];
 943                         } elseif ( isset( $exitCodeMap["*"] ) ) {
 944                                 $mappedCode = $exitCodeMap["*"];
 945                         }
 946                 }
 947
 948                 if ( $mappedCode === AV_SCAN_FAILED ) {
 949                         # scan failed (code was mapped to false by $exitCodeMap)
 950                         wfDebug( __METHOD__ . ": failed to scan $file (code $exitCode).\n" );
 951
 952                         if ( $wgAntivirusRequired ) {
 953                                 return wfMsg( 'virus-scanfailed', array( $exitCode ) );
 954                         } else {
 955                                 return null;
 956                         }
 957                 } elseif ( $mappedCode === AV_SCAN_ABORTED ) {
 958                         # scan failed because filetype is unknown (probably imune)
 959                         wfDebug( __METHOD__ . ": unsupported file type $file (code $exitCode).\n" );
 960                         return null;
 961                 } elseif ( $mappedCode === AV_NO_VIRUS ) {
 962                         # no virus found
 963                         wfDebug( __METHOD__ . ": file passed virus scan.\n" );
 964                         return false;
 965                 } else {
 966                         $output = trim( $output );
 967
 968                         if ( !$output ) {
 969                                 $output = true; #if there's no output, return true
 970                         } elseif ( $msgPattern ) {
 971                                 $groups = array();
 972                                 if ( preg_match( $msgPattern, $output, $groups ) ) {
 973                                         if ( $groups[1] ) {
 974                                                 $output = $groups[1];
 975                                         }
 976                                 }
 977                         }
 978
 979                         wfDebug( __METHOD__ . ": FOUND VIRUS! scanner feedback: $output \n" );
 980                         return $output;
 981                 }
 982         }
 983
 984         /**
 985          * Check if the temporary file is MacBinary-encoded, as some uploads
 986          * from Internet Explorer on Mac OS Classic and Mac OS X will be.
 987          * If so, the data fork will be extracted to a second temporary file,
 988          * which will then be checked for validity and either kept or discarded.
 989          */
 990         private function checkMacBinary() {
 991                 $macbin = new MacBinary( $this->mTempPath );
 992                 if( $macbin->isValid() ) {
 993                         $dataFile = tempnam( wfTempDir(), 'WikiMacBinary' );
 994                         $dataHandle = fopen( $dataFile, 'wb' );
 995
 996                         wfDebug( __METHOD__ . ": Extracting MacBinary data fork to $dataFile\n" );
 997                         $macbin->extractData( $dataHandle );
 998
 999                         $this->mTempPath = $dataFile;
1000                         $this->mFileSize = $macbin->dataForkLength();
1001
1002                         // We'll have to manually remove the new file if it's not kept.
1003                         $this->mRemoveTempFile = true;
1004                 }
1005                 $macbin->close();
1006         }
1007
1008         /**
1009          * Check if there's an overwrite conflict and, if so, if restrictions
1010          * forbid this user from performing the upload.
1011          *
1012          * @return mixed true on success, error string on failure
1013          */
1014         private function checkOverwrite( $user ) {
1015                 // First check whether the local file can be overwritten
1016                 $file = $this->getLocalFile();
1017                 if( $file->exists() ) {
1018                         if( !self::userCanReUpload( $user, $file ) ) {
1019                                 return 'fileexists-forbidden';
1020                         } else {
1021                                 return true;
1022                         }
1023                 }
1024
1025                 /* Check shared conflicts: if the local file does not exist, but
1026                  * wfFindFile finds a file, it exists in a shared repository.
1027                  */
1028                 $file = wfFindFile( $this->getTitle() );
1029                 if ( $file && !$user->isAllowed( 'reupload-shared' ) ) {
1030                         return 'fileexists-shared-forbidden';
1031                 }
1032
1033                 return true;
1034         }
1035
1036         /**
1037          * Check if a user is the last uploader
1038          *
1039          * @param $user User object
1040          * @param $img String: image name
1041          * @return Boolean
1042          */
1043         public static function userCanReUpload( User $user, $img ) {
1044                 if( $user->isAllowed( 'reupload' ) ) {
1045                         return true; // non-conditional
1046                 }
1047                 if( !$user->isAllowed( 'reupload-own' ) ) {
1048                         return false;
1049                 }
1050                 if( is_string( $img ) ) {
1051                         $img = wfLocalFile( $img );
1052                 }
1053                 if ( !( $img instanceof LocalFile ) ) {
1054                         return false;
1055                 }
1056
1057                 return $user->getId() == $img->getUser( 'id' );
1058         }
1059
1060         /**
1061          * Helper function that does various existence checks for a file.
1062          * The following checks are performed:
1063          * - The file exists
1064          * - Article with the same name as the file exists
1065          * - File exists with normalized extension
1066          * - The file looks like a thumbnail and the original exists
1067          *
1068          * @param $file The File object to check
1069          * @return mixed False if the file does not exists, else an array
1070          */
1071         public static function getExistsWarning( $file ) {
1072                 if( $file->exists() ) {
1073                         return array( 'warning' => 'exists', 'file' => $file );
1074                 }
1075
1076                 if( $file->getTitle()->getArticleID() ) {
1077                         return array( 'warning' => 'page-exists', 'file' => $file );
1078                 }
1079
1080                 if ( $file->wasDeleted() && !$file->exists() ) {
1081                         return array( 'warning' => 'was-deleted', 'file' => $file );
1082                 }
1083
1084                 if( strpos( $file->getName(), '.' ) == false ) {
1085                         $partname = $file->getName();
1086                         $extension = '';
1087                 } else {
1088                         $n = strrpos( $file->getName(), '.' );
1089                         $extension = substr( $file->getName(), $n + 1 );
1090                         $partname = substr( $file->getName(), 0, $n );
1091                 }
1092                 $normalizedExtension = File::normalizeExtension( $extension );
1093
1094                 if ( $normalizedExtension != $extension ) {
1095                         // We're not using the normalized form of the extension.
1096                         // Normal form is lowercase, using most common of alternate
1097                         // extensions (eg 'jpg' rather than 'JPEG').
1098                         //
1099                         // Check for another file using the normalized form...
1100                         $nt_lc = Title::makeTitle( NS_FILE, "{$partname}.{$normalizedExtension}" );
1101                         $file_lc = wfLocalFile( $nt_lc );
1102
1103                         if( $file_lc->exists() ) {
1104                                 return array(
1105                                         'warning' => 'exists-normalized',
1106                                         'file' => $file,
1107                                         'normalizedFile' => $file_lc
1108                                 );
1109                         }
1110                 }
1111
1112                 if ( self::isThumbName( $file->getName() ) ) {
1113                         # Check for filenames like 50px- or 180px-, these are mostly thumbnails
1114                         $nt_thb = Title::newFromText( substr( $partname , strpos( $partname , '-' ) +1 ) . '.' . $extension, NS_FILE );
1115                         $file_thb = wfLocalFile( $nt_thb );
1116                         if( $file_thb->exists() ) {
1117                                 return array(
1118                                         'warning' => 'thumb',
1119                                         'file' => $file,
1120                                         'thumbFile' => $file_thb
1121                                 );
1122                         } else {
1123                                 // File does not exist, but we just don't like the name
1124                                 return array(
1125                                         'warning' => 'thumb-name',
1126                                         'file' => $file,
1127                                         'thumbFile' => $file_thb
1128                                 );
1129                         }
1130                 }
1131
1132
1133                 foreach( self::getFilenamePrefixBlacklist() as $prefix ) {
1134                         if ( substr( $partname, 0, strlen( $prefix ) ) == $prefix ) {
1135                                 return array(
1136                                         'warning' => 'bad-prefix',
1137                                         'file' => $file,
1138                                         'prefix' => $prefix
1139                                 );
1140                         }
1141                 }
1142
1143                 return false;
1144         }
1145
1146         /**
1147          * Helper function that checks whether the filename looks like a thumbnail
1148          */
1149         public static function isThumbName( $filename ) {
1150                 $n = strrpos( $filename, '.' );
1151                 $partname = $n ? substr( $filename, 0, $n ) : $filename;
1152                 return (
1153                                         substr( $partname , 3, 3 ) == 'px-' ||
1154                                         substr( $partname , 2, 3 ) == 'px-'
1155                                 ) &&
1156                                 preg_match( "/[0-9]{2}/" , substr( $partname , 0, 2 ) );
1157         }
1158
1159         /**
1160          * Get a list of blacklisted filename prefixes from [[MediaWiki:Filename-prefix-blacklist]]
1161          *
1162          * @return array list of prefixes
1163          */
1164         public static function getFilenamePrefixBlacklist() {
1165                 $blacklist = array();
1166                 $message = wfMsgForContent( 'filename-prefix-blacklist' );
1167                 if( $message && !( wfEmptyMsg( 'filename-prefix-blacklist', $message ) || $message == '-' ) ) {
1168                         $lines = explode( "\n", $message );
1169                         foreach( $lines as $line ) {
1170                                 // Remove comment lines
1171                                 $comment = substr( trim( $line ), 0, 1 );
1172                                 if ( $comment == '#' || $comment == '' ) {
1173                                         continue;
1174                                 }
1175                                 // Remove additional comments after a prefix
1176                                 $comment = strpos( $line, '#' );
1177                                 if ( $comment > 0 ) {
1178                                         $line = substr( $line, 0, $comment-1 );
1179                                 }
1180                                 $blacklist[] = trim( $line );
1181                         }
1182                 }
1183                 return $blacklist;
1184         }
1185
1186         public function getImageInfo( $result ) {
1187                 $file = $this->getLocalFile();
1188                 $imParam = ApiQueryImageInfo::getPropertyNames();
1189                 return ApiQueryImageInfo::getInfo( $file, array_flip( $imParam ), $result );
1190         }
1191
1192         public function convertVerifyErrorToStatus( $error ) {
1193                 $code = $error['status'];
1194                 unset( $code['status'] );
1195                 return Status::newFatal( $this->getVerificationErrorCode( $code ), $error );
1196         }
1197 }