includes/upload/UploadBase.php

   1 <?php
   2 /**
   3  * Base class for the backend of file upload.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Upload
  22  */
  23 use MediaWiki\MediaWikiServices;
  24
  25 /**
  26  * @defgroup Upload Upload related
  27  */
  28
  29 /**
  30  * @ingroup Upload
  31  *
  32  * UploadBase and subclasses are the backend of MediaWiki's file uploads.
  33  * The frontends are formed by ApiUpload and SpecialUpload.
  34  *
  35  * @author Brion Vibber
  36  * @author Bryan Tong Minh
  37  * @author Michael Dale
  38  */
  39 abstract class UploadBase {
  40         /** @var string Local file system path to the file to upload (or a local copy) */
  41         protected $mTempPath;
  42         /** @var TempFSFile|null Wrapper to handle deleting the temp file */
  43         protected $tempFileObj;
  44
  45         protected $mDesiredDestName, $mDestName, $mRemoveTempFile, $mSourceType;
  46         protected $mTitle = false, $mTitleError = 0;
  47         protected $mFilteredName, $mFinalExtension;
  48         protected $mLocalFile, $mStashFile, $mFileSize, $mFileProps;
  49         protected $mBlackListedExtensions;
  50         protected $mJavaDetected, $mSVGNSError;
  51
  52         protected static $safeXmlEncodings = [
  53                 'UTF-8',
  54                 'ISO-8859-1',
  55                 'ISO-8859-2',
  56                 'UTF-16',
  57                 'UTF-32',
  58                 'WINDOWS-1250',
  59                 'WINDOWS-1251',
  60                 'WINDOWS-1252',
  61                 'WINDOWS-1253',
  62                 'WINDOWS-1254',
  63                 'WINDOWS-1255',
  64                 'WINDOWS-1256',
  65                 'WINDOWS-1257',
  66                 'WINDOWS-1258',
  67         ];
  68
  69         const SUCCESS = 0;
  70         const OK = 0;
  71         const EMPTY_FILE = 3;
  72         const MIN_LENGTH_PARTNAME = 4;
  73         const ILLEGAL_FILENAME = 5;
  74         const OVERWRITE_EXISTING_FILE = 7; # Not used anymore; handled by verifyTitlePermissions()
  75         const FILETYPE_MISSING = 8;
  76         const FILETYPE_BADTYPE = 9;
  77         const VERIFICATION_ERROR = 10;
  78         const HOOK_ABORTED = 11;
  79         const FILE_TOO_LARGE = 12;
  80         const WINDOWS_NONASCII_FILENAME = 13;
  81         const FILENAME_TOO_LONG = 14;
  82
  83         /**
  84          * @param int $error
  85          * @return string
  86          */
  87         public function getVerificationErrorCode( $error ) {
  88                 $code_to_status = [
  89                         self::EMPTY_FILE => 'empty-file',
  90                         self::FILE_TOO_LARGE => 'file-too-large',
  91                         self::FILETYPE_MISSING => 'filetype-missing',
  92                         self::FILETYPE_BADTYPE => 'filetype-banned',
  93                         self::MIN_LENGTH_PARTNAME => 'filename-tooshort',
  94                         self::ILLEGAL_FILENAME => 'illegal-filename',
  95                         self::OVERWRITE_EXISTING_FILE => 'overwrite',
  96                         self::VERIFICATION_ERROR => 'verification-error',
  97                         self::HOOK_ABORTED => 'hookaborted',
  98                         self::WINDOWS_NONASCII_FILENAME => 'windows-nonascii-filename',
  99                         self::FILENAME_TOO_LONG => 'filename-toolong',
 100                 ];
 101                 if ( isset( $code_to_status[$error] ) ) {
 102                         return $code_to_status[$error];
 103                 }
 104
 105                 return 'unknown-error';
 106         }
 107
 108         /**
 109          * Returns true if uploads are enabled.
 110          * Can be override by subclasses.
 111          * @return bool
 112          */
 113         public static function isEnabled() {
 114                 global $wgEnableUploads;
 115
 116                 if ( !$wgEnableUploads ) {
 117                         return false;
 118                 }
 119
 120                 # Check php's file_uploads setting
 121                 return wfIsHHVM() || wfIniGetBool( 'file_uploads' );
 122         }
 123
 124         /**
 125          * Returns true if the user can use this upload module or else a string
 126          * identifying the missing permission.
 127          * Can be overridden by subclasses.
 128          *
 129          * @param User $user
 130          * @return bool|string
 131          */
 132         public static function isAllowed( $user ) {
 133                 foreach ( [ 'upload', 'edit' ] as $permission ) {
 134                         if ( !$user->isAllowed( $permission ) ) {
 135                                 return $permission;
 136                         }
 137                 }
 138
 139                 return true;
 140         }
 141
 142         /**
 143          * Returns true if the user has surpassed the upload rate limit, false otherwise.
 144          *
 145          * @param User $user
 146          * @return bool
 147          */
 148         public static function isThrottled( $user ) {
 149                 return $user->pingLimiter( 'upload' );
 150         }
 151
 152         // Upload handlers. Should probably just be a global.
 153         private static $uploadHandlers = [ 'Stash', 'File', 'Url' ];
 154
 155         /**
 156          * Create a form of UploadBase depending on wpSourceType and initializes it
 157          *
 158          * @param WebRequest &$request
 159          * @param string|null $type
 160          * @return null|UploadBase
 161          */
 162         public static function createFromRequest( &$request, $type = null ) {
 163                 $type = $type ? $type : $request->getVal( 'wpSourceType', 'File' );
 164
 165                 if ( !$type ) {
 166                         return null;
 167                 }
 168
 169                 // Get the upload class
 170                 $type = ucfirst( $type );
 171
 172                 // Give hooks the chance to handle this request
 173                 $className = null;
 174                 Hooks::run( 'UploadCreateFromRequest', [ $type, &$className ] );
 175                 if ( is_null( $className ) ) {
 176                         $className = 'UploadFrom' . $type;
 177                         wfDebug( __METHOD__ . ": class name: $className\n" );
 178                         if ( !in_array( $type, self::$uploadHandlers ) ) {
 179                                 return null;
 180                         }
 181                 }
 182
 183                 // Check whether this upload class is enabled
 184                 if ( !call_user_func( [ $className, 'isEnabled' ] ) ) {
 185                         return null;
 186                 }
 187
 188                 // Check whether the request is valid
 189                 if ( !call_user_func( [ $className, 'isValidRequest' ], $request ) ) {
 190                         return null;
 191                 }
 192
 193                 /** @var UploadBase $handler */
 194                 $handler = new $className;
 195
 196                 $handler->initializeFromRequest( $request );
 197
 198                 return $handler;
 199         }
 200
 201         /**
 202          * Check whether a request if valid for this handler
 203          * @param WebRequest $request
 204          * @return bool
 205          */
 206         public static function isValidRequest( $request ) {
 207                 return false;
 208         }
 209
 210         public function __construct() {
 211         }
 212
 213         /**
 214          * Returns the upload type. Should be overridden by child classes
 215          *
 216          * @since 1.18
 217          * @return string
 218          */
 219         public function getSourceType() {
 220                 return null;
 221         }
 222
 223         /**
 224          * Initialize the path information
 225          * @param string $name The desired destination name
 226          * @param string $tempPath The temporary path
 227          * @param int $fileSize The file size
 228          * @param bool $removeTempFile (false) remove the temporary file?
 229          * @throws MWException
 230          */
 231         public function initializePathInfo( $name, $tempPath, $fileSize, $removeTempFile = false ) {
 232                 $this->mDesiredDestName = $name;
 233                 if ( FileBackend::isStoragePath( $tempPath ) ) {
 234                         throw new MWException( __METHOD__ . " given storage path `$tempPath`." );
 235                 }
 236
 237                 $this->setTempFile( $tempPath, $fileSize );
 238                 $this->mRemoveTempFile = $removeTempFile;
 239         }
 240
 241         /**
 242          * Initialize from a WebRequest. Override this in a subclass.
 243          *
 244          * @param WebRequest &$request
 245          */
 246         abstract public function initializeFromRequest( &$request );
 247
 248         /**
 249          * @param string $tempPath File system path to temporary file containing the upload
 250          * @param int $fileSize
 251          */
 252         protected function setTempFile( $tempPath, $fileSize = null ) {
 253                 $this->mTempPath = $tempPath;
 254                 $this->mFileSize = $fileSize ?: null;
 255                 if ( strlen( $this->mTempPath ) && file_exists( $this->mTempPath ) ) {
 256                         $this->tempFileObj = new TempFSFile( $this->mTempPath );
 257                         if ( !$fileSize ) {
 258                                 $this->mFileSize = filesize( $this->mTempPath );
 259                         }
 260                 } else {
 261                         $this->tempFileObj = null;
 262                 }
 263         }
 264
 265         /**
 266          * Fetch the file. Usually a no-op
 267          * @return Status
 268          */
 269         public function fetchFile() {
 270                 return Status::newGood();
 271         }
 272
 273         /**
 274          * Return true if the file is empty
 275          * @return bool
 276          */
 277         public function isEmptyFile() {
 278                 return empty( $this->mFileSize );
 279         }
 280
 281         /**
 282          * Return the file size
 283          * @return int
 284          */
 285         public function getFileSize() {
 286                 return $this->mFileSize;
 287         }
 288
 289         /**
 290          * Get the base 36 SHA1 of the file
 291          * @return string
 292          */
 293         public function getTempFileSha1Base36() {
 294                 return FSFile::getSha1Base36FromPath( $this->mTempPath );
 295         }
 296
 297         /**
 298          * @param string $srcPath The source path
 299          * @return string|bool The real path if it was a virtual URL Returns false on failure
 300          */
 301         public function getRealPath( $srcPath ) {
 302                 $repo = RepoGroup::singleton()->getLocalRepo();
 303                 if ( $repo->isVirtualUrl( $srcPath ) ) {
 304                         /** @todo Just make uploads work with storage paths UploadFromStash
 305                          *  loads files via virtual URLs.
 306                          */
 307                         $tmpFile = $repo->getLocalCopy( $srcPath );
 308                         if ( $tmpFile ) {
 309                                 $tmpFile->bind( $this ); // keep alive with $this
 310                         }
 311                         $path = $tmpFile ? $tmpFile->getPath() : false;
 312                 } else {
 313                         $path = $srcPath;
 314                 }
 315
 316                 return $path;
 317         }
 318
 319         /**
 320          * Verify whether the upload is sane.
 321          * @return mixed Const self::OK or else an array with error information
 322          */
 323         public function verifyUpload() {
 324                 /**
 325                  * If there was no filename or a zero size given, give up quick.
 326                  */
 327                 if ( $this->isEmptyFile() ) {
 328                         return [ 'status' => self::EMPTY_FILE ];
 329                 }
 330
 331                 /**
 332                  * Honor $wgMaxUploadSize
 333                  */
 334                 $maxSize = self::getMaxUploadSize( $this->getSourceType() );
 335                 if ( $this->mFileSize > $maxSize ) {
 336                         return [
 337                                 'status' => self::FILE_TOO_LARGE,
 338                                 'max' => $maxSize,
 339                         ];
 340                 }
 341
 342                 /**
 343                  * Look at the contents of the file; if we can recognize the
 344                  * type but it's corrupt or data of the wrong type, we should
 345                  * probably not accept it.
 346                  */
 347                 $verification = $this->verifyFile();
 348                 if ( $verification !== true ) {
 349                         return [
 350                                 'status' => self::VERIFICATION_ERROR,
 351                                 'details' => $verification
 352                         ];
 353                 }
 354
 355                 /**
 356                  * Make sure this file can be created
 357                  */
 358                 $result = $this->validateName();
 359                 if ( $result !== true ) {
 360                         return $result;
 361                 }
 362
 363                 $error = '';
 364                 if ( !Hooks::run( 'UploadVerification',
 365                         [ $this->mDestName, $this->mTempPath, &$error ], '1.28' )
 366                 ) {
 367                         return [ 'status' => self::HOOK_ABORTED, 'error' => $error ];
 368                 }
 369
 370                 return [ 'status' => self::OK ];
 371         }
 372
 373         /**
 374          * Verify that the name is valid and, if necessary, that we can overwrite
 375          *
 376          * @return mixed True if valid, otherwise and array with 'status'
 377          * and other keys
 378          */
 379         public function validateName() {
 380                 $nt = $this->getTitle();
 381                 if ( is_null( $nt ) ) {
 382                         $result = [ 'status' => $this->mTitleError ];
 383                         if ( $this->mTitleError == self::ILLEGAL_FILENAME ) {
 384                                 $result['filtered'] = $this->mFilteredName;
 385                         }
 386                         if ( $this->mTitleError == self::FILETYPE_BADTYPE ) {
 387                                 $result['finalExt'] = $this->mFinalExtension;
 388                                 if ( count( $this->mBlackListedExtensions ) ) {
 389                                         $result['blacklistedExt'] = $this->mBlackListedExtensions;
 390                                 }
 391                         }
 392
 393                         return $result;
 394                 }
 395                 $this->mDestName = $this->getLocalFile()->getName();
 396
 397                 return true;
 398         }
 399
 400         /**
 401          * Verify the MIME type.
 402          *
 403          * @note Only checks that it is not an evil MIME. The "does it have
 404          *  correct extension given its MIME type?" check is in verifyFile.
 405          *  in `verifyFile()` that MIME type and file extension correlate.
 406          * @param string $mime Representing the MIME
 407          * @return mixed True if the file is verified, an array otherwise
 408          */
 409         protected function verifyMimeType( $mime ) {
 410                 global $wgVerifyMimeType;
 411                 if ( $wgVerifyMimeType ) {
 412                         wfDebug( "mime: <$mime> extension: <{$this->mFinalExtension}>\n" );
 413                         global $wgMimeTypeBlacklist;
 414                         if ( $this->checkFileExtension( $mime, $wgMimeTypeBlacklist ) ) {
 415                                 return [ 'filetype-badmime', $mime ];
 416                         }
 417
 418                         # Check what Internet Explorer would detect
 419                         $fp = fopen( $this->mTempPath, 'rb' );
 420                         $chunk = fread( $fp, 256 );
 421                         fclose( $fp );
 422
 423                         $magic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
 424                         $extMime = $magic->guessTypesForExtension( $this->mFinalExtension );
 425                         $ieTypes = $magic->getIEMimeTypes( $this->mTempPath, $chunk, $extMime );
 426                         foreach ( $ieTypes as $ieType ) {
 427                                 if ( $this->checkFileExtension( $ieType, $wgMimeTypeBlacklist ) ) {
 428                                         return [ 'filetype-bad-ie-mime', $ieType ];
 429                                 }
 430                         }
 431                 }
 432
 433                 return true;
 434         }
 435
 436         /**
 437          * Verifies that it's ok to include the uploaded file
 438          *
 439          * @return mixed True of the file is verified, array otherwise.
 440          */
 441         protected function verifyFile() {
 442                 global $wgVerifyMimeType, $wgDisableUploadScriptChecks;
 443
 444                 $status = $this->verifyPartialFile();
 445                 if ( $status !== true ) {
 446                         return $status;
 447                 }
 448
 449                 $mwProps = new MWFileProps( MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer() );
 450                 $this->mFileProps = $mwProps->getPropsFromPath( $this->mTempPath, $this->mFinalExtension );
 451                 $mime = $this->mFileProps['mime'];
 452
 453                 if ( $wgVerifyMimeType ) {
 454                         # XXX: Missing extension will be caught by validateName() via getTitle()
 455                         if ( $this->mFinalExtension != '' && !$this->verifyExtension( $mime, $this->mFinalExtension ) ) {
 456                                 return [ 'filetype-mime-mismatch', $this->mFinalExtension, $mime ];
 457                         }
 458                 }
 459
 460                 # check for htmlish code and javascript
 461                 if ( !$wgDisableUploadScriptChecks ) {
 462                         if ( $this->mFinalExtension == 'svg' || $mime == 'image/svg+xml' ) {
 463                                 $svgStatus = $this->detectScriptInSvg( $this->mTempPath, false );
 464                                 if ( $svgStatus !== false ) {
 465                                         return $svgStatus;
 466                                 }
 467                         }
 468                 }
 469
 470                 $handler = MediaHandler::getHandler( $mime );
 471                 if ( $handler ) {
 472                         $handlerStatus = $handler->verifyUpload( $this->mTempPath );
 473                         if ( !$handlerStatus->isOK() ) {
 474                                 $errors = $handlerStatus->getErrorsArray();
 475
 476                                 return reset( $errors );
 477                         }
 478                 }
 479
 480                 $error = true;
 481                 Hooks::run( 'UploadVerifyFile', [ $this, $mime, &$error ] );
 482                 if ( $error !== true ) {
 483                         if ( !is_array( $error ) ) {
 484                                 $error = [ $error ];
 485                         }
 486                         return $error;
 487                 }
 488
 489                 wfDebug( __METHOD__ . ": all clear; passing.\n" );
 490
 491                 return true;
 492         }
 493
 494         /**
 495          * A verification routine suitable for partial files
 496          *
 497          * Runs the blacklist checks, but not any checks that may
 498          * assume the entire file is present.
 499          *
 500          * @return mixed True for valid or array with error message key.
 501          */
 502         protected function verifyPartialFile() {
 503                 global $wgAllowJavaUploads, $wgDisableUploadScriptChecks;
 504
 505                 # getTitle() sets some internal parameters like $this->mFinalExtension
 506                 $this->getTitle();
 507
 508                 $mwProps = new MWFileProps( MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer() );
 509                 $this->mFileProps = $mwProps->getPropsFromPath( $this->mTempPath, $this->mFinalExtension );
 510
 511                 # check MIME type, if desired
 512                 $mime = $this->mFileProps['file-mime'];
 513                 $status = $this->verifyMimeType( $mime );
 514                 if ( $status !== true ) {
 515                         return $status;
 516                 }
 517
 518                 # check for htmlish code and javascript
 519                 if ( !$wgDisableUploadScriptChecks ) {
 520                         if ( self::detectScript( $this->mTempPath, $mime, $this->mFinalExtension ) ) {
 521                                 return [ 'uploadscripted' ];
 522                         }
 523                         if ( $this->mFinalExtension == 'svg' || $mime == 'image/svg+xml' ) {
 524                                 $svgStatus = $this->detectScriptInSvg( $this->mTempPath, true );
 525                                 if ( $svgStatus !== false ) {
 526                                         return $svgStatus;
 527                                 }
 528                         }
 529                 }
 530
 531                 # Check for Java applets, which if uploaded can bypass cross-site
 532                 # restrictions.
 533                 if ( !$wgAllowJavaUploads ) {
 534                         $this->mJavaDetected = false;
 535                         $zipStatus = ZipDirectoryReader::read( $this->mTempPath,
 536                                 [ $this, 'zipEntryCallback' ] );
 537                         if ( !$zipStatus->isOK() ) {
 538                                 $errors = $zipStatus->getErrorsArray();
 539                                 $error = reset( $errors );
 540                                 if ( $error[0] !== 'zip-wrong-format' ) {
 541                                         return $error;
 542                                 }
 543                         }
 544                         if ( $this->mJavaDetected ) {
 545                                 return [ 'uploadjava' ];
 546                         }
 547                 }
 548
 549                 # Scan the uploaded file for viruses
 550                 $virus = $this->detectVirus( $this->mTempPath );
 551                 if ( $virus ) {
 552                         return [ 'uploadvirus', $virus ];
 553                 }
 554
 555                 return true;
 556         }
 557
 558         /**
 559          * Callback for ZipDirectoryReader to detect Java class files.
 560          *
 561          * @param array $entry
 562          */
 563         public function zipEntryCallback( $entry ) {
 564                 $names = [ $entry['name'] ];
 565
 566                 // If there is a null character, cut off the name at it, because JDK's
 567                 // ZIP_GetEntry() uses strcmp() if the name hashes match. If a file name
 568                 // were constructed which had ".class\0" followed by a string chosen to
 569                 // make the hash collide with the truncated name, that file could be
 570                 // returned in response to a request for the .class file.
 571                 $nullPos = strpos( $entry['name'], "\000" );
 572                 if ( $nullPos !== false ) {
 573                         $names[] = substr( $entry['name'], 0, $nullPos );
 574                 }
 575
 576                 // If there is a trailing slash in the file name, we have to strip it,
 577                 // because that's what ZIP_GetEntry() does.
 578                 if ( preg_grep( '!\.class/?$!', $names ) ) {
 579                         $this->mJavaDetected = true;
 580                 }
 581         }
 582
 583         /**
 584          * Alias for verifyTitlePermissions. The function was originally
 585          * 'verifyPermissions', but that suggests it's checking the user, when it's
 586          * really checking the title + user combination.
 587          *
 588          * @param User $user User object to verify the permissions against
 589          * @return mixed An array as returned by getUserPermissionsErrors or true
 590          *   in case the user has proper permissions.
 591          */
 592         public function verifyPermissions( $user ) {
 593                 return $this->verifyTitlePermissions( $user );
 594         }
 595
 596         /**
 597          * Check whether the user can edit, upload and create the image. This
 598          * checks only against the current title; if it returns errors, it may
 599          * very well be that another title will not give errors. Therefore
 600          * isAllowed() should be called as well for generic is-user-blocked or
 601          * can-user-upload checking.
 602          *
 603          * @param User $user User object to verify the permissions against
 604          * @return mixed An array as returned by getUserPermissionsErrors or true
 605          *   in case the user has proper permissions.
 606          */
 607         public function verifyTitlePermissions( $user ) {
 608                 /**
 609                  * If the image is protected, non-sysop users won't be able
 610                  * to modify it by uploading a new revision.
 611                  */
 612                 $nt = $this->getTitle();
 613                 if ( is_null( $nt ) ) {
 614                         return true;
 615                 }
 616                 $permErrors = $nt->getUserPermissionsErrors( 'edit', $user );
 617                 $permErrorsUpload = $nt->getUserPermissionsErrors( 'upload', $user );
 618                 if ( !$nt->exists() ) {
 619                         $permErrorsCreate = $nt->getUserPermissionsErrors( 'create', $user );
 620                 } else {
 621                         $permErrorsCreate = [];
 622                 }
 623                 if ( $permErrors || $permErrorsUpload || $permErrorsCreate ) {
 624                         $permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsUpload, $permErrors ) );
 625                         $permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsCreate, $permErrors ) );
 626
 627                         return $permErrors;
 628                 }
 629
 630                 $overwriteError = $this->checkOverwrite( $user );
 631                 if ( $overwriteError !== true ) {
 632                         return [ $overwriteError ];
 633                 }
 634
 635                 return true;
 636         }
 637
 638         /**
 639          * Check for non fatal problems with the file.
 640          *
 641          * This should not assume that mTempPath is set.
 642          *
 643          * @return mixed[] Array of warnings
 644          */
 645         public function checkWarnings() {
 646                 $warnings = [];
 647
 648                 $localFile = $this->getLocalFile();
 649                 $localFile->load( File::READ_LATEST );
 650                 $filename = $localFile->getName();
 651                 $hash = $this->getTempFileSha1Base36();
 652
 653                 $badFileName = $this->checkBadFileName( $filename, $this->mDesiredDestName );
 654                 if ( $badFileName !== null ) {
 655                         $warnings['badfilename'] = $badFileName;
 656                 }
 657
 658                 $unwantedFileExtensionDetails = $this->checkUnwantedFileExtensions( $this->mFinalExtension );
 659                 if ( $unwantedFileExtensionDetails !== null ) {
 660                         $warnings['filetype-unwanted-type'] = $unwantedFileExtensionDetails;
 661                 }
 662
 663                 $fileSizeWarnings = $this->checkFileSize( $this->mFileSize );
 664                 if ( $fileSizeWarnings ) {
 665                         $warnings = array_merge( $warnings, $fileSizeWarnings );
 666                 }
 667
 668                 $localFileExistsWarnings = $this->checkLocalFileExists( $localFile, $hash );
 669                 if ( $localFileExistsWarnings ) {
 670                         $warnings = array_merge( $warnings, $localFileExistsWarnings );
 671                 }
 672
 673                 if ( $this->checkLocalFileWasDeleted( $localFile ) ) {
 674                         $warnings['was-deleted'] = $filename;
 675                 }
 676
 677                 // If a file with the same name exists locally then the local file has already been tested
 678                 // for duplication of content
 679                 $ignoreLocalDupes = isset( $warnings[ 'exists '] );
 680                 $dupes = $this->checkAgainstExistingDupes( $hash, $ignoreLocalDupes );
 681                 if ( $dupes ) {
 682                         $warnings['duplicate'] = $dupes;
 683                 }
 684
 685                 $archivedDupes = $this->checkAgainstArchiveDupes( $hash );
 686                 if ( $archivedDupes !== null ) {
 687                         $warnings['duplicate-archive'] = $archivedDupes;
 688                 }
 689
 690                 return $warnings;
 691         }
 692
 693         /**
 694          * Check whether the resulting filename is different from the desired one,
 695          * but ignore things like ucfirst() and spaces/underscore things
 696          *
 697          * @param string $filename
 698          * @param string $desiredFileName
 699          *
 700          * @return string|null String that was determined to be bad or null if the filename is okay
 701          */
 702         private function checkBadFileName( $filename, $desiredFileName ) {
 703                 $comparableName = str_replace( ' ', '_', $desiredFileName );
 704                 $comparableName = Title::capitalize( $comparableName, NS_FILE );
 705
 706                 if ( $desiredFileName != $filename && $comparableName != $filename ) {
 707                         return $filename;
 708                 }
 709
 710                 return null;
 711         }
 712
 713         /**
 714          * @param string $fileExtension The file extension to check
 715          *
 716          * @return array|null array with the following keys:
 717          *                    0 => string The final extension being used
 718          *                    1 => string[] The extensions that are allowed
 719          *                    2 => int The number of extensions that are allowed.
 720          */
 721         private function checkUnwantedFileExtensions( $fileExtension ) {
 722                 global $wgCheckFileExtensions, $wgFileExtensions, $wgLang;
 723
 724                 if ( $wgCheckFileExtensions ) {
 725                         $extensions = array_unique( $wgFileExtensions );
 726                         if ( !$this->checkFileExtension( $fileExtension, $extensions ) ) {
 727                                 return [
 728                                         $fileExtension,
 729                                         $wgLang->commaList( $extensions ),
 730                                         count( $extensions )
 731                                 ];
 732                         }
 733                 }
 734
 735                 return null;
 736         }
 737
 738         /**
 739          * @param int $fileSize
 740          *
 741          * @return array warnings
 742          */
 743         private function checkFileSize( $fileSize ) {
 744                 global $wgUploadSizeWarning;
 745
 746                 $warnings = [];
 747
 748                 if ( $wgUploadSizeWarning && ( $fileSize > $wgUploadSizeWarning ) ) {
 749                         $warnings['large-file'] = [ $wgUploadSizeWarning, $fileSize ];
 750                 }
 751
 752                 if ( $fileSize == 0 ) {
 753                         $warnings['empty-file'] = true;
 754                 }
 755
 756                 return $warnings;
 757         }
 758
 759         /**
 760          * @param LocalFile $localFile
 761          * @param string $hash sha1 hash of the file to check
 762          *
 763          * @return array warnings
 764          */
 765         private function checkLocalFileExists( LocalFile $localFile, $hash ) {
 766                 $warnings = [];
 767
 768                 $exists = self::getExistsWarning( $localFile );
 769                 if ( $exists !== false ) {
 770                         $warnings['exists'] = $exists;
 771
 772                         // check if file is an exact duplicate of current file version
 773                         if ( $hash === $localFile->getSha1() ) {
 774                                 $warnings['no-change'] = $localFile;
 775                         }
 776
 777                         // check if file is an exact duplicate of older versions of this file
 778                         $history = $localFile->getHistory();
 779                         foreach ( $history as $oldFile ) {
 780                                 if ( $hash === $oldFile->getSha1() ) {
 781                                         $warnings['duplicate-version'][] = $oldFile;
 782                                 }
 783                         }
 784                 }
 785
 786                 return $warnings;
 787         }
 788
 789         private function checkLocalFileWasDeleted( LocalFile $localFile ) {
 790                 return $localFile->wasDeleted() && !$localFile->exists();
 791         }
 792
 793         /**
 794          * @param string $hash sha1 hash of the file to check
 795          * @param bool $ignoreLocalDupes True to ignore local duplicates
 796          *
 797          * @return File[] Duplicate files, if found.
 798          */
 799         private function checkAgainstExistingDupes( $hash, $ignoreLocalDupes ) {
 800                 $dupes = RepoGroup::singleton()->findBySha1( $hash );
 801                 $title = $this->getTitle();
 802                 foreach ( $dupes as $key => $dupe ) {
 803                         if (
 804                                 ( $dupe instanceof LocalFile ) &&
 805                                 $ignoreLocalDupes &&
 806                                 $title->equals( $dupe->getTitle() )
 807                         ) {
 808                                 unset( $dupes[$key] );
 809                         }
 810                 }
 811
 812                 return $dupes;
 813         }
 814
 815         /**
 816          * @param string $hash sha1 hash of the file to check
 817          *
 818          * @return string|null Name of the dupe or empty string if discovered (depending on visibility)
 819          *                     null if the check discovered no dupes.
 820          */
 821         private function checkAgainstArchiveDupes( $hash ) {
 822                 $archivedFile = new ArchivedFile( null, 0, '', $hash );
 823                 if ( $archivedFile->getID() > 0 ) {
 824                         if ( $archivedFile->userCan( File::DELETED_FILE ) ) {
 825                                 return $archivedFile->getName();
 826                         } else {
 827                                 return '';
 828                         }
 829                 }
 830
 831                 return null;
 832         }
 833
 834         /**
 835          * Really perform the upload. Stores the file in the local repo, watches
 836          * if necessary and runs the UploadComplete hook.
 837          *
 838          * @param string $comment
 839          * @param string $pageText
 840          * @param bool $watch Whether the file page should be added to user's watchlist.
 841          *   (This doesn't check $user's permissions.)
 842          * @param User $user
 843          * @param string[] $tags Change tags to add to the log entry and page revision.
 844          *   (This doesn't check $user's permissions.)
 845          * @return Status Indicating the whether the upload succeeded.
 846          */
 847         public function performUpload( $comment, $pageText, $watch, $user, $tags = [] ) {
 848                 $this->getLocalFile()->load( File::READ_LATEST );
 849                 $props = $this->mFileProps;
 850
 851                 $error = null;
 852                 Hooks::run( 'UploadVerifyUpload', [ $this, $user, $props, $comment, $pageText, &$error ] );
 853                 if ( $error ) {
 854                         if ( !is_array( $error ) ) {
 855                                 $error = [ $error ];
 856                         }
 857                         return call_user_func_array( 'Status::newFatal', $error );
 858                 }
 859
 860                 $status = $this->getLocalFile()->upload(
 861                         $this->mTempPath,
 862                         $comment,
 863                         $pageText,
 864                         File::DELETE_SOURCE,
 865                         $props,
 866                         false,
 867                         $user,
 868                         $tags
 869                 );
 870
 871                 if ( $status->isGood() ) {
 872                         if ( $watch ) {
 873                                 WatchAction::doWatch(
 874                                         $this->getLocalFile()->getTitle(),
 875                                         $user,
 876                                         User::IGNORE_USER_RIGHTS
 877                                 );
 878                         }
 879                         // Avoid PHP 7.1 warning of passing $this by reference
 880                         $uploadBase = $this;
 881                         Hooks::run( 'UploadComplete', [ &$uploadBase ] );
 882
 883                         $this->postProcessUpload();
 884                 }
 885
 886                 return $status;
 887         }
 888
 889         /**
 890          * Perform extra steps after a successful upload.
 891          *
 892          * @since  1.25
 893          */
 894         public function postProcessUpload() {
 895         }
 896
 897         /**
 898          * Returns the title of the file to be uploaded. Sets mTitleError in case
 899          * the name was illegal.
 900          *
 901          * @return Title|null The title of the file or null in case the name was illegal
 902          */
 903         public function getTitle() {
 904                 if ( $this->mTitle !== false ) {
 905                         return $this->mTitle;
 906                 }
 907                 if ( !is_string( $this->mDesiredDestName ) ) {
 908                         $this->mTitleError = self::ILLEGAL_FILENAME;
 909                         $this->mTitle = null;
 910
 911                         return $this->mTitle;
 912                 }
 913                 /* Assume that if a user specified File:Something.jpg, this is an error
 914                  * and that the namespace prefix needs to be stripped of.
 915                  */
 916                 $title = Title::newFromText( $this->mDesiredDestName );
 917                 if ( $title && $title->getNamespace() == NS_FILE ) {
 918                         $this->mFilteredName = $title->getDBkey();
 919                 } else {
 920                         $this->mFilteredName = $this->mDesiredDestName;
 921                 }
 922
 923                 # oi_archive_name is max 255 bytes, which include a timestamp and an
 924                 # exclamation mark, so restrict file name to 240 bytes.
 925                 if ( strlen( $this->mFilteredName ) > 240 ) {
 926                         $this->mTitleError = self::FILENAME_TOO_LONG;
 927                         $this->mTitle = null;
 928
 929                         return $this->mTitle;
 930                 }
 931
 932                 /**
 933                  * Chop off any directories in the given filename. Then
 934                  * filter out illegal characters, and try to make a legible name
 935                  * out of it. We'll strip some silently that Title would die on.
 936                  */
 937                 $this->mFilteredName = wfStripIllegalFilenameChars( $this->mFilteredName );
 938                 /* Normalize to title form before we do any further processing */
 939                 $nt = Title::makeTitleSafe( NS_FILE, $this->mFilteredName );
 940                 if ( is_null( $nt ) ) {
 941                         $this->mTitleError = self::ILLEGAL_FILENAME;
 942                         $this->mTitle = null;
 943
 944                         return $this->mTitle;
 945                 }
 946                 $this->mFilteredName = $nt->getDBkey();
 947
 948                 /**
 949                  * We'll want to blacklist against *any* 'extension', and use
 950                  * only the final one for the whitelist.
 951                  */
 952                 list( $partname, $ext ) = $this->splitExtensions( $this->mFilteredName );
 953
 954                 if ( count( $ext ) ) {
 955                         $this->mFinalExtension = trim( $ext[count( $ext ) - 1] );
 956                 } else {
 957                         $this->mFinalExtension = '';
 958
 959                         # No extension, try guessing one
 960                         $magic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
 961                         $mime = $magic->guessMimeType( $this->mTempPath );
 962                         if ( $mime !== 'unknown/unknown' ) {
 963                                 # Get a space separated list of extensions
 964                                 $extList = $magic->getExtensionsForType( $mime );
 965                                 if ( $extList ) {
 966                                         # Set the extension to the canonical extension
 967                                         $this->mFinalExtension = strtok( $extList, ' ' );
 968
 969                                         # Fix up the other variables
 970                                         $this->mFilteredName .= ".{$this->mFinalExtension}";
 971                                         $nt = Title::makeTitleSafe( NS_FILE, $this->mFilteredName );
 972                                         $ext = [ $this->mFinalExtension ];
 973                                 }
 974                         }
 975                 }
 976
 977                 /* Don't allow users to override the blacklist (check file extension) */
 978                 global $wgCheckFileExtensions, $wgStrictFileExtensions;
 979                 global $wgFileExtensions, $wgFileBlacklist;
 980
 981                 $blackListedExtensions = $this->checkFileExtensionList( $ext, $wgFileBlacklist );
 982
 983                 if ( $this->mFinalExtension == '' ) {
 984                         $this->mTitleError = self::FILETYPE_MISSING;
 985                         $this->mTitle = null;
 986
 987                         return $this->mTitle;
 988                 } elseif ( $blackListedExtensions ||
 989                         ( $wgCheckFileExtensions && $wgStrictFileExtensions &&
 990                                 !$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) )
 991                 ) {
 992                         $this->mBlackListedExtensions = $blackListedExtensions;
 993                         $this->mTitleError = self::FILETYPE_BADTYPE;
 994                         $this->mTitle = null;
 995
 996                         return $this->mTitle;
 997                 }
 998
 999                 // Windows may be broken with special characters, see T3780
1000                 if ( !preg_match( '/^[\x0-\x7f]*$/', $nt->getText() )
1001                         && !RepoGroup::singleton()->getLocalRepo()->backendSupportsUnicodePaths()
1002                 ) {
1003                         $this->mTitleError = self::WINDOWS_NONASCII_FILENAME;
1004                         $this->mTitle = null;
1005
1006                         return $this->mTitle;
1007                 }
1008
1009                 # If there was more than one "extension", reassemble the base
1010                 # filename to prevent bogus complaints about length
1011                 if ( count( $ext ) > 1 ) {
1012                         $iterations = count( $ext ) - 1;
1013                         for ( $i = 0; $i < $iterations; $i++ ) {
1014                                 $partname .= '.' . $ext[$i];
1015                         }
1016                 }
1017
1018                 if ( strlen( $partname ) < 1 ) {
1019                         $this->mTitleError = self::MIN_LENGTH_PARTNAME;
1020                         $this->mTitle = null;
1021
1022                         return $this->mTitle;
1023                 }
1024
1025                 $this->mTitle = $nt;
1026
1027                 return $this->mTitle;
1028         }
1029
1030         /**
1031          * Return the local file and initializes if necessary.
1032          *
1033          * @return LocalFile|null
1034          */
1035         public function getLocalFile() {
1036                 if ( is_null( $this->mLocalFile ) ) {
1037                         $nt = $this->getTitle();
1038                         $this->mLocalFile = is_null( $nt ) ? null : wfLocalFile( $nt );
1039                 }
1040
1041                 return $this->mLocalFile;
1042         }
1043
1044         /**
1045          * @return UploadStashFile|null
1046          */
1047         public function getStashFile() {
1048                 return $this->mStashFile;
1049         }
1050
1051         /**
1052          * Like stashFile(), but respects extensions' wishes to prevent the stashing. verifyUpload() must
1053          * be called before calling this method (unless $isPartial is true).
1054          *
1055          * Upload stash exceptions are also caught and converted to an error status.
1056          *
1057          * @since 1.28
1058          * @param User $user
1059          * @param bool $isPartial Pass `true` if this is a part of a chunked upload (not a complete file).
1060          * @return Status If successful, value is an UploadStashFile instance
1061          */
1062         public function tryStashFile( User $user, $isPartial = false ) {
1063                 if ( !$isPartial ) {
1064                         $error = $this->runUploadStashFileHook( $user );
1065                         if ( $error ) {
1066                                 return call_user_func_array( 'Status::newFatal', $error );
1067                         }
1068                 }
1069                 try {
1070                         $file = $this->doStashFile( $user );
1071                         return Status::newGood( $file );
1072                 } catch ( UploadStashException $e ) {
1073                         return Status::newFatal( 'uploadstash-exception', get_class( $e ), $e->getMessage() );
1074                 }
1075         }
1076
1077         /**
1078          * @param User $user
1079          * @return array|null Error message and parameters, null if there's no error
1080          */
1081         protected function runUploadStashFileHook( User $user ) {
1082                 $props = $this->mFileProps;
1083                 $error = null;
1084                 Hooks::run( 'UploadStashFile', [ $this, $user, $props, &$error ] );
1085                 if ( $error ) {
1086                         if ( !is_array( $error ) ) {
1087                                 $error = [ $error ];
1088                         }
1089                 }
1090                 return $error;
1091         }
1092
1093         /**
1094          * If the user does not supply all necessary information in the first upload
1095          * form submission (either by accident or by design) then we may want to
1096          * stash the file temporarily, get more information, and publish the file
1097          * later.
1098          *
1099          * This method will stash a file in a temporary directory for later
1100          * processing, and save the necessary descriptive info into the database.
1101          * This method returns the file object, which also has a 'fileKey' property
1102          * which can be passed through a form or API request to find this stashed
1103          * file again.
1104          *
1105          * @deprecated since 1.28 Use tryStashFile() instead
1106          * @param User $user
1107          * @return UploadStashFile Stashed file
1108          * @throws UploadStashBadPathException
1109          * @throws UploadStashFileException
1110          * @throws UploadStashNotLoggedInException
1111          */
1112         public function stashFile( User $user = null ) {
1113                 return $this->doStashFile( $user );
1114         }
1115
1116         /**
1117          * Implementation for stashFile() and tryStashFile().
1118          *
1119          * @param User $user
1120          * @return UploadStashFile Stashed file
1121          */
1122         protected function doStashFile( User $user = null ) {
1123                 $stash = RepoGroup::singleton()->getLocalRepo()->getUploadStash( $user );
1124                 $file = $stash->stashFile( $this->mTempPath, $this->getSourceType() );
1125                 $this->mStashFile = $file;
1126
1127                 return $file;
1128         }
1129
1130         /**
1131          * Stash a file in a temporary directory, returning a key which can be used
1132          * to find the file again. See stashFile().
1133          *
1134          * @deprecated since 1.28
1135          * @return string File key
1136          */
1137         public function stashFileGetKey() {
1138                 wfDeprecated( __METHOD__, '1.28' );
1139                 return $this->doStashFile()->getFileKey();
1140         }
1141
1142         /**
1143          * alias for stashFileGetKey, for backwards compatibility
1144          *
1145          * @deprecated since 1.28
1146          * @return string File key
1147          */
1148         public function stashSession() {
1149                 wfDeprecated( __METHOD__, '1.28' );
1150                 return $this->doStashFile()->getFileKey();
1151         }
1152
1153         /**
1154          * If we've modified the upload file we need to manually remove it
1155          * on exit to clean up.
1156          */
1157         public function cleanupTempFile() {
1158                 if ( $this->mRemoveTempFile && $this->tempFileObj ) {
1159                         // Delete when all relevant TempFSFile handles go out of scope
1160                         wfDebug( __METHOD__ . ": Marked temporary file '{$this->mTempPath}' for removal\n" );
1161                         $this->tempFileObj->autocollect();
1162                 }
1163         }
1164
1165         public function getTempPath() {
1166                 return $this->mTempPath;
1167         }
1168
1169         /**
1170          * Split a file into a base name and all dot-delimited 'extensions'
1171          * on the end. Some web server configurations will fall back to
1172          * earlier pseudo-'extensions' to determine type and execute
1173          * scripts, so the blacklist needs to check them all.
1174          *
1175          * @param string $filename
1176          * @return array
1177          */
1178         public static function splitExtensions( $filename ) {
1179                 $bits = explode( '.', $filename );
1180                 $basename = array_shift( $bits );
1181
1182                 return [ $basename, $bits ];
1183         }
1184
1185         /**
1186          * Perform case-insensitive match against a list of file extensions.
1187          * Returns true if the extension is in the list.
1188          *
1189          * @param string $ext
1190          * @param array $list
1191          * @return bool
1192          */
1193         public static function checkFileExtension( $ext, $list ) {
1194                 return in_array( strtolower( $ext ), $list );
1195         }
1196
1197         /**
1198          * Perform case-insensitive match against a list of file extensions.
1199          * Returns an array of matching extensions.
1200          *
1201          * @param array $ext
1202          * @param array $list
1203          * @return bool
1204          */
1205         public static function checkFileExtensionList( $ext, $list ) {
1206                 return array_intersect( array_map( 'strtolower', $ext ), $list );
1207         }
1208
1209         /**
1210          * Checks if the MIME type of the uploaded file matches the file extension.
1211          *
1212          * @param string $mime The MIME type of the uploaded file
1213          * @param string $extension The filename extension that the file is to be served with
1214          * @return bool
1215          */
1216         public static function verifyExtension( $mime, $extension ) {
1217                 $magic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
1218
1219                 if ( !$mime || $mime == 'unknown' || $mime == 'unknown/unknown' ) {
1220                         if ( !$magic->isRecognizableExtension( $extension ) ) {
1221                                 wfDebug( __METHOD__ . ": passing file with unknown detected mime type; " .
1222                                         "unrecognized extension '$extension', can't verify\n" );
1223
1224                                 return true;
1225                         } else {
1226                                 wfDebug( __METHOD__ . ": rejecting file with unknown detected mime type; " .
1227                                         "recognized extension '$extension', so probably invalid file\n" );
1228
1229                                 return false;
1230                         }
1231                 }
1232
1233                 $match = $magic->isMatchingExtension( $extension, $mime );
1234
1235                 if ( $match === null ) {
1236                         if ( $magic->getTypesForExtension( $extension ) !== null ) {
1237                                 wfDebug( __METHOD__ . ": No extension known for $mime, but we know a mime for $extension\n" );
1238
1239                                 return false;
1240                         } else {
1241                                 wfDebug( __METHOD__ . ": no file extension known for mime type $mime, passing file\n" );
1242
1243                                 return true;
1244                         }
1245                 } elseif ( $match === true ) {
1246                         wfDebug( __METHOD__ . ": mime type $mime matches extension $extension, passing file\n" );
1247
1248                         /** @todo If it's a bitmap, make sure PHP or ImageMagick resp. can handle it! */
1249                         return true;
1250                 } else {
1251                         wfDebug( __METHOD__
1252                                 . ": mime type $mime mismatches file extension $extension, rejecting file\n" );
1253
1254                         return false;
1255                 }
1256         }
1257
1258         /**
1259          * Heuristic for detecting files that *could* contain JavaScript instructions or
1260          * things that may look like HTML to a browser and are thus
1261          * potentially harmful. The present implementation will produce false
1262          * positives in some situations.
1263          *
1264          * @param string $file Pathname to the temporary upload file
1265          * @param string $mime The MIME type of the file
1266          * @param string $extension The extension of the file
1267          * @return bool True if the file contains something looking like embedded scripts
1268          */
1269         public static function detectScript( $file, $mime, $extension ) {
1270                 global $wgAllowTitlesInSVG;
1271
1272                 # ugly hack: for text files, always look at the entire file.
1273                 # For binary field, just check the first K.
1274
1275                 if ( strpos( $mime, 'text/' ) === 0 ) {
1276                         $chunk = file_get_contents( $file );
1277                 } else {
1278                         $fp = fopen( $file, 'rb' );
1279                         $chunk = fread( $fp, 1024 );
1280                         fclose( $fp );
1281                 }
1282
1283                 $chunk = strtolower( $chunk );
1284
1285                 if ( !$chunk ) {
1286                         return false;
1287                 }
1288
1289                 # decode from UTF-16 if needed (could be used for obfuscation).
1290                 if ( substr( $chunk, 0, 2 ) == "\xfe\xff" ) {
1291                         $enc = 'UTF-16BE';
1292                 } elseif ( substr( $chunk, 0, 2 ) == "\xff\xfe" ) {
1293                         $enc = 'UTF-16LE';
1294                 } else {
1295                         $enc = null;
1296                 }
1297
1298                 if ( $enc ) {
1299                         $chunk = iconv( $enc, "ASCII//IGNORE", $chunk );
1300                 }
1301
1302                 $chunk = trim( $chunk );
1303
1304                 /** @todo FIXME: Convert from UTF-16 if necessary! */
1305                 wfDebug( __METHOD__ . ": checking for embedded scripts and HTML stuff\n" );
1306
1307                 # check for HTML doctype
1308                 if ( preg_match( "/<!DOCTYPE *X?HTML/i", $chunk ) ) {
1309                         return true;
1310                 }
1311
1312                 // Some browsers will interpret obscure xml encodings as UTF-8, while
1313                 // PHP/expat will interpret the given encoding in the xml declaration (T49304)
1314                 if ( $extension == 'svg' || strpos( $mime, 'image/svg' ) === 0 ) {
1315                         if ( self::checkXMLEncodingMissmatch( $file ) ) {
1316                                 return true;
1317                         }
1318                 }
1319
1320                 /**
1321                  * Internet Explorer for Windows performs some really stupid file type
1322                  * autodetection which can cause it to interpret valid image files as HTML
1323                  * and potentially execute JavaScript, creating a cross-site scripting
1324                  * attack vectors.
1325                  *
1326                  * Apple's Safari browser also performs some unsafe file type autodetection
1327                  * which can cause legitimate files to be interpreted as HTML if the
1328                  * web server is not correctly configured to send the right content-type
1329                  * (or if you're really uploading plain text and octet streams!)
1330                  *
1331                  * Returns true if IE is likely to mistake the given file for HTML.
1332                  * Also returns true if Safari would mistake the given file for HTML
1333                  * when served with a generic content-type.
1334                  */
1335                 $tags = [
1336                         '<a href',
1337                         '<body',
1338                         '<head',
1339                         '<html', # also in safari
1340                         '<img',
1341                         '<pre',
1342                         '<script', # also in safari
1343                         '<table'
1344                 ];
1345
1346                 if ( !$wgAllowTitlesInSVG && $extension !== 'svg' && $mime !== 'image/svg' ) {
1347                         $tags[] = '<title';
1348                 }
1349
1350                 foreach ( $tags as $tag ) {
1351                         if ( false !== strpos( $chunk, $tag ) ) {
1352                                 wfDebug( __METHOD__ . ": found something that may make it be mistaken for html: $tag\n" );
1353
1354                                 return true;
1355                         }
1356                 }
1357
1358                 /*
1359                  * look for JavaScript
1360                  */
1361
1362                 # resolve entity-refs to look at attributes. may be harsh on big files... cache result?
1363                 $chunk = Sanitizer::decodeCharReferences( $chunk );
1364
1365                 # look for script-types
1366                 if ( preg_match( '!type\s*=\s*[\'"]?\s*(?:\w*/)?(?:ecma|java)!sim', $chunk ) ) {
1367                         wfDebug( __METHOD__ . ": found script types\n" );
1368
1369                         return true;
1370                 }
1371
1372                 # look for html-style script-urls
1373                 if ( preg_match( '!(?:href|src|data)\s*=\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
1374                         wfDebug( __METHOD__ . ": found html-style script urls\n" );
1375
1376                         return true;
1377                 }
1378
1379                 # look for css-style script-urls
1380                 if ( preg_match( '!url\s*\(\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
1381                         wfDebug( __METHOD__ . ": found css-style script urls\n" );
1382
1383                         return true;
1384                 }
1385
1386                 wfDebug( __METHOD__ . ": no scripts found\n" );
1387
1388                 return false;
1389         }
1390
1391         /**
1392          * Check a whitelist of xml encodings that are known not to be interpreted differently
1393          * by the server's xml parser (expat) and some common browsers.
1394          *
1395          * @param string $file Pathname to the temporary upload file
1396          * @return bool True if the file contains an encoding that could be misinterpreted
1397          */
1398         public static function checkXMLEncodingMissmatch( $file ) {
1399                 global $wgSVGMetadataCutoff;
1400                 $contents = file_get_contents( $file, false, null, -1, $wgSVGMetadataCutoff );
1401                 $encodingRegex = '!encoding[ \t\n\r]*=[ \t\n\r]*[\'"](.*?)[\'"]!si';
1402
1403                 if ( preg_match( "!<\?xml\b(.*?)\?>!si", $contents, $matches ) ) {
1404                         if ( preg_match( $encodingRegex, $matches[1], $encMatch )
1405                                 && !in_array( strtoupper( $encMatch[1] ), self::$safeXmlEncodings )
1406                         ) {
1407                                 wfDebug( __METHOD__ . ": Found unsafe XML encoding '{$encMatch[1]}'\n" );
1408
1409                                 return true;
1410                         }
1411                 } elseif ( preg_match( "!<\?xml\b!si", $contents ) ) {
1412                         // Start of XML declaration without an end in the first $wgSVGMetadataCutoff
1413                         // bytes. There shouldn't be a legitimate reason for this to happen.
1414                         wfDebug( __METHOD__ . ": Unmatched XML declaration start\n" );
1415
1416                         return true;
1417                 } elseif ( substr( $contents, 0, 4 ) == "\x4C\x6F\xA7\x94" ) {
1418                         // EBCDIC encoded XML
1419                         wfDebug( __METHOD__ . ": EBCDIC Encoded XML\n" );
1420
1421                         return true;
1422                 }
1423
1424                 // It's possible the file is encoded with multi-byte encoding, so re-encode attempt to
1425                 // detect the encoding in case is specifies an encoding not whitelisted in self::$safeXmlEncodings
1426                 $attemptEncodings = [ 'UTF-16', 'UTF-16BE', 'UTF-32', 'UTF-32BE' ];
1427                 foreach ( $attemptEncodings as $encoding ) {
1428                         Wikimedia\suppressWarnings();
1429                         $str = iconv( $encoding, 'UTF-8', $contents );
1430                         Wikimedia\restoreWarnings();
1431                         if ( $str != '' && preg_match( "!<\?xml\b(.*?)\?>!si", $str, $matches ) ) {
1432                                 if ( preg_match( $encodingRegex, $matches[1], $encMatch )
1433                                         && !in_array( strtoupper( $encMatch[1] ), self::$safeXmlEncodings )
1434                                 ) {
1435                                         wfDebug( __METHOD__ . ": Found unsafe XML encoding '{$encMatch[1]}'\n" );
1436
1437                                         return true;
1438                                 }
1439                         } elseif ( $str != '' && preg_match( "!<\?xml\b!si", $str ) ) {
1440                                 // Start of XML declaration without an end in the first $wgSVGMetadataCutoff
1441                                 // bytes. There shouldn't be a legitimate reason for this to happen.
1442                                 wfDebug( __METHOD__ . ": Unmatched XML declaration start\n" );
1443
1444                                 return true;
1445                         }
1446                 }
1447
1448                 return false;
1449         }
1450
1451         /**
1452          * @param string $filename
1453          * @param bool $partial
1454          * @return mixed False of the file is verified (does not contain scripts), array otherwise.
1455          */
1456         protected function detectScriptInSvg( $filename, $partial ) {
1457                 $this->mSVGNSError = false;
1458                 $check = new XmlTypeCheck(
1459                         $filename,
1460                         [ $this, 'checkSvgScriptCallback' ],
1461                         true,
1462                         [
1463                                 'processing_instruction_handler' => 'UploadBase::checkSvgPICallback',
1464                                 'external_dtd_handler' => 'UploadBase::checkSvgExternalDTD',
1465                         ]
1466                 );
1467                 if ( $check->wellFormed !== true ) {
1468                         // Invalid xml (T60553)
1469                         // But only when non-partial (T67724)
1470                         return $partial ? false : [ 'uploadinvalidxml' ];
1471                 } elseif ( $check->filterMatch ) {
1472                         if ( $this->mSVGNSError ) {
1473                                 return [ 'uploadscriptednamespace', $this->mSVGNSError ];
1474                         }
1475
1476                         return $check->filterMatchType;
1477                 }
1478
1479                 return false;
1480         }
1481
1482         /**
1483          * Callback to filter SVG Processing Instructions.
1484          * @param string $target Processing instruction name
1485          * @param string $data Processing instruction attribute and value
1486          * @return bool (true if the filter identified something bad)
1487          */
1488         public static function checkSvgPICallback( $target, $data ) {
1489                 // Don't allow external stylesheets (T59550)
1490                 if ( preg_match( '/xml-stylesheet/i', $target ) ) {
1491                         return [ 'upload-scripted-pi-callback' ];
1492                 }
1493
1494                 return false;
1495         }
1496
1497         /**
1498          * Verify that DTD urls referenced are only the standard dtds
1499          *
1500          * Browsers seem to ignore external dtds. However just to be on the
1501          * safe side, only allow dtds from the svg standard.
1502          *
1503          * @param string $type PUBLIC or SYSTEM
1504          * @param string $publicId The well-known public identifier for the dtd
1505          * @param string $systemId The url for the external dtd
1506          * @return bool|array
1507          */
1508         public static function checkSvgExternalDTD( $type, $publicId, $systemId ) {
1509                 // This doesn't include the XHTML+MathML+SVG doctype since we don't
1510                 // allow XHTML anyways.
1511                 $allowedDTDs = [
1512                         'http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd',
1513                         'http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd',
1514                         'http://www.w3.org/Graphics/SVG/1.1/DTD/svg11-basic.dtd',
1515                         'http://www.w3.org/Graphics/SVG/1.1/DTD/svg11-tiny.dtd',
1516                         // https://phabricator.wikimedia.org/T168856
1517                         'http://www.w3.org/TR/2001/PR-SVG-20010719/DTD/svg10.dtd',
1518                 ];
1519                 if ( $type !== 'PUBLIC'
1520                         || !in_array( $systemId, $allowedDTDs )
1521                         || strpos( $publicId, "-//W3C//" ) !== 0
1522                 ) {
1523                         return [ 'upload-scripted-dtd' ];
1524                 }
1525                 return false;
1526         }
1527
1528         /**
1529          * @todo Replace this with a whitelist filter!
1530          * @param string $element
1531          * @param array $attribs
1532          * @param array $data
1533          * @return bool
1534          */
1535         public function checkSvgScriptCallback( $element, $attribs, $data = null ) {
1536                 list( $namespace, $strippedElement ) = $this->splitXmlNamespace( $element );
1537
1538                 // We specifically don't include:
1539                 // http://www.w3.org/1999/xhtml (T62771)
1540                 static $validNamespaces = [
1541                         '',
1542                         'adobe:ns:meta/',
1543                         'http://creativecommons.org/ns#',
1544                         'http://inkscape.sourceforge.net/dtd/sodipodi-0.dtd',
1545                         'http://ns.adobe.com/adobeillustrator/10.0/',
1546                         'http://ns.adobe.com/adobesvgviewerextensions/3.0/',
1547                         'http://ns.adobe.com/extensibility/1.0/',
1548                         'http://ns.adobe.com/flows/1.0/',
1549                         'http://ns.adobe.com/illustrator/1.0/',
1550                         'http://ns.adobe.com/imagereplacement/1.0/',
1551                         'http://ns.adobe.com/pdf/1.3/',
1552                         'http://ns.adobe.com/photoshop/1.0/',
1553                         'http://ns.adobe.com/saveforweb/1.0/',
1554                         'http://ns.adobe.com/variables/1.0/',
1555                         'http://ns.adobe.com/xap/1.0/',
1556                         'http://ns.adobe.com/xap/1.0/g/',
1557                         'http://ns.adobe.com/xap/1.0/g/img/',
1558                         'http://ns.adobe.com/xap/1.0/mm/',
1559                         'http://ns.adobe.com/xap/1.0/rights/',
1560                         'http://ns.adobe.com/xap/1.0/stype/dimensions#',
1561                         'http://ns.adobe.com/xap/1.0/stype/font#',
1562                         'http://ns.adobe.com/xap/1.0/stype/manifestitem#',
1563                         'http://ns.adobe.com/xap/1.0/stype/resourceevent#',
1564                         'http://ns.adobe.com/xap/1.0/stype/resourceref#',
1565                         'http://ns.adobe.com/xap/1.0/t/pg/',
1566                         'http://purl.org/dc/elements/1.1/',
1567                         'http://purl.org/dc/elements/1.1',
1568                         'http://schemas.microsoft.com/visio/2003/svgextensions/',
1569                         'http://sodipodi.sourceforge.net/dtd/sodipodi-0.dtd',
1570                         'http://taptrix.com/inkpad/svg_extensions',
1571                         'http://web.resource.org/cc/',
1572                         'http://www.freesoftware.fsf.org/bkchem/cdml',
1573                         'http://www.inkscape.org/namespaces/inkscape',
1574                         'http://www.opengis.net/gml',
1575                         'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
1576                         'http://www.w3.org/2000/svg',
1577                         'http://www.w3.org/tr/rec-rdf-syntax/',
1578                         'http://www.w3.org/2000/01/rdf-schema#',
1579                 ];
1580
1581                 // Inkscape mangles namespace definitions created by Adobe Illustrator.
1582                 // This is nasty but harmless. (T144827)
1583                 $isBuggyInkscape = preg_match( '/^&(#38;)*ns_[a-z_]+;$/', $namespace );
1584
1585                 if ( !( $isBuggyInkscape || in_array( $namespace, $validNamespaces ) ) ) {
1586                         wfDebug( __METHOD__ . ": Non-svg namespace '$namespace' in uploaded file.\n" );
1587                         /** @todo Return a status object to a closure in XmlTypeCheck, for MW1.21+ */
1588                         $this->mSVGNSError = $namespace;
1589
1590                         return true;
1591                 }
1592
1593                 /*
1594                  * check for elements that can contain javascript
1595                  */
1596                 if ( $strippedElement == 'script' ) {
1597                         wfDebug( __METHOD__ . ": Found script element '$element' in uploaded file.\n" );
1598
1599                         return [ 'uploaded-script-svg', $strippedElement ];
1600                 }
1601
1602                 # e.g., <svg xmlns="http://www.w3.org/2000/svg">
1603                 #  <handler xmlns:ev="http://www.w3.org/2001/xml-events" ev:event="load">alert(1)</handler> </svg>
1604                 if ( $strippedElement == 'handler' ) {
1605                         wfDebug( __METHOD__ . ": Found scriptable element '$element' in uploaded file.\n" );
1606
1607                         return [ 'uploaded-script-svg', $strippedElement ];
1608                 }
1609
1610                 # SVG reported in Feb '12 that used xml:stylesheet to generate javascript block
1611                 if ( $strippedElement == 'stylesheet' ) {
1612                         wfDebug( __METHOD__ . ": Found scriptable element '$element' in uploaded file.\n" );
1613
1614                         return [ 'uploaded-script-svg', $strippedElement ];
1615                 }
1616
1617                 # Block iframes, in case they pass the namespace check
1618                 if ( $strippedElement == 'iframe' ) {
1619                         wfDebug( __METHOD__ . ": iframe in uploaded file.\n" );
1620
1621                         return [ 'uploaded-script-svg', $strippedElement ];
1622                 }
1623
1624                 # Check <style> css
1625                 if ( $strippedElement == 'style'
1626                         && self::checkCssFragment( Sanitizer::normalizeCss( $data ) )
1627                 ) {
1628                         wfDebug( __METHOD__ . ": hostile css in style element.\n" );
1629                         return [ 'uploaded-hostile-svg' ];
1630                 }
1631
1632                 foreach ( $attribs as $attrib => $value ) {
1633                         $stripped = $this->stripXmlNamespace( $attrib );
1634                         $value = strtolower( $value );
1635
1636                         if ( substr( $stripped, 0, 2 ) == 'on' ) {
1637                                 wfDebug( __METHOD__
1638                                         . ": Found event-handler attribute '$attrib'='$value' in uploaded file.\n" );
1639
1640                                 return [ 'uploaded-event-handler-on-svg', $attrib, $value ];
1641                         }
1642
1643                         # Do not allow relative links, or unsafe url schemas.
1644                         # For <a> tags, only data:, http: and https: and same-document
1645                         # fragment links are allowed. For all other tags, only data:
1646                         # and fragment are allowed.
1647                         if ( $stripped == 'href'
1648                                 && $value !== ''
1649                                 && strpos( $value, 'data:' ) !== 0
1650                                 && strpos( $value, '#' ) !== 0
1651                         ) {
1652                                 if ( !( $strippedElement === 'a'
1653                                         && preg_match( '!^https?://!i', $value ) )
1654                                 ) {
1655                                         wfDebug( __METHOD__ . ": Found href attribute <$strippedElement "
1656                                                 . "'$attrib'='$value' in uploaded file.\n" );
1657
1658                                         return [ 'uploaded-href-attribute-svg', $strippedElement, $attrib, $value ];
1659                                 }
1660                         }
1661
1662                         # only allow data: targets that should be safe. This prevents vectors like,
1663                         # image/svg, text/xml, application/xml, and text/html, which can contain scripts
1664                         if ( $stripped == 'href' && strncasecmp( 'data:', $value, 5 ) === 0 ) {
1665                                 // rfc2397 parameters. This is only slightly slower than (;[\w;]+)*.
1666                                 // phpcs:ignore Generic.Files.LineLength
1667                                 $parameters = '(?>;[a-zA-Z0-9\!#$&\'*+.^_`{|}~-]+=(?>[a-zA-Z0-9\!#$&\'*+.^_`{|}~-]+|"(?>[\0-\x0c\x0e-\x21\x23-\x5b\x5d-\x7f]+|\\\\[\0-\x7f])*"))*(?:;base64)?';
1668
1669                                 if ( !preg_match( "!^data:\s*image/(gif|jpeg|jpg|png)$parameters,!i", $value ) ) {
1670                                         wfDebug( __METHOD__ . ": Found href to unwhitelisted data: uri "
1671                                                 . "\"<$strippedElement '$attrib'='$value'...\" in uploaded file.\n" );
1672                                         return [ 'uploaded-href-unsafe-target-svg', $strippedElement, $attrib, $value ];
1673                                 }
1674                         }
1675
1676                         # Change href with animate from (http://html5sec.org/#137).
1677                         if ( $stripped === 'attributename'
1678                                 && $strippedElement === 'animate'
1679                                 && $this->stripXmlNamespace( $value ) == 'href'
1680                         ) {
1681                                 wfDebug( __METHOD__ . ": Found animate that might be changing href using from "
1682                                         . "\"<$strippedElement '$attrib'='$value'...\" in uploaded file.\n" );
1683
1684                                 return [ 'uploaded-animate-svg', $strippedElement, $attrib, $value ];
1685                         }
1686
1687                         # use set/animate to add event-handler attribute to parent
1688                         if ( ( $strippedElement == 'set' || $strippedElement == 'animate' )
1689                                 && $stripped == 'attributename'
1690                                 && substr( $value, 0, 2 ) == 'on'
1691                         ) {
1692                                 wfDebug( __METHOD__ . ": Found svg setting event-handler attribute with "
1693                                         . "\"<$strippedElement $stripped='$value'...\" in uploaded file.\n" );
1694
1695                                 return [ 'uploaded-setting-event-handler-svg', $strippedElement, $stripped, $value ];
1696                         }
1697
1698                         # use set to add href attribute to parent element
1699                         if ( $strippedElement == 'set'
1700                                 && $stripped == 'attributename'
1701                                 && strpos( $value, 'href' ) !== false
1702                         ) {
1703                                 wfDebug( __METHOD__ . ": Found svg setting href attribute '$value' in uploaded file.\n" );
1704
1705                                 return [ 'uploaded-setting-href-svg' ];
1706                         }
1707
1708                         # use set to add a remote / data / script target to an element
1709                         if ( $strippedElement == 'set'
1710                                 && $stripped == 'to'
1711                                 && preg_match( '!(http|https|data|script):!sim', $value )
1712                         ) {
1713                                 wfDebug( __METHOD__ . ": Found svg setting attribute to '$value' in uploaded file.\n" );
1714
1715                                 return [ 'uploaded-wrong-setting-svg', $value ];
1716                         }
1717
1718                         # use handler attribute with remote / data / script
1719                         if ( $stripped == 'handler' && preg_match( '!(http|https|data|script):!sim', $value ) ) {
1720                                 wfDebug( __METHOD__ . ": Found svg setting handler with remote/data/script "
1721                                         . "'$attrib'='$value' in uploaded file.\n" );
1722
1723                                 return [ 'uploaded-setting-handler-svg', $attrib, $value ];
1724                         }
1725
1726                         # use CSS styles to bring in remote code
1727                         if ( $stripped == 'style'
1728                                 && self::checkCssFragment( Sanitizer::normalizeCss( $value ) )
1729                         ) {
1730                                 wfDebug( __METHOD__ . ": Found svg setting a style with "
1731                                         . "remote url '$attrib'='$value' in uploaded file.\n" );
1732                                 return [ 'uploaded-remote-url-svg', $attrib, $value ];
1733                         }
1734
1735                         # Several attributes can include css, css character escaping isn't allowed
1736                         $cssAttrs = [ 'font', 'clip-path', 'fill', 'filter', 'marker',
1737                                 'marker-end', 'marker-mid', 'marker-start', 'mask', 'stroke' ];
1738                         if ( in_array( $stripped, $cssAttrs )
1739                                 && self::checkCssFragment( $value )
1740                         ) {
1741                                 wfDebug( __METHOD__ . ": Found svg setting a style with "
1742                                         . "remote url '$attrib'='$value' in uploaded file.\n" );
1743                                 return [ 'uploaded-remote-url-svg', $attrib, $value ];
1744                         }
1745
1746                         # image filters can pull in url, which could be svg that executes scripts
1747                         if ( $strippedElement == 'image'
1748                                 && $stripped == 'filter'
1749                                 && preg_match( '!url\s*\(!sim', $value )
1750                         ) {
1751                                 wfDebug( __METHOD__ . ": Found image filter with url: "
1752                                         . "\"<$strippedElement $stripped='$value'...\" in uploaded file.\n" );
1753
1754                                 return [ 'uploaded-image-filter-svg', $strippedElement, $stripped, $value ];
1755                         }
1756                 }
1757
1758                 return false; // No scripts detected
1759         }
1760
1761         /**
1762          * Check a block of CSS or CSS fragment for anything that looks like
1763          * it is bringing in remote code.
1764          * @param string $value a string of CSS
1765          * @param bool $propOnly only check css properties (start regex with :)
1766          * @return bool true if the CSS contains an illegal string, false if otherwise
1767          */
1768         private static function checkCssFragment( $value ) {
1769                 # Forbid external stylesheets, for both reliability and to protect viewer's privacy
1770                 if ( stripos( $value, '@import' ) !== false ) {
1771                         return true;
1772                 }
1773
1774                 # We allow @font-face to embed fonts with data: urls, so we snip the string
1775                 # 'url' out so this case won't match when we check for urls below
1776                 $pattern = '!(@font-face\s*{[^}]*src:)url(\("data:;base64,)!im';
1777                 $value = preg_replace( $pattern, '$1$2', $value );
1778
1779                 # Check for remote and executable CSS. Unlike in Sanitizer::checkCss, the CSS
1780                 # properties filter and accelerator don't seem to be useful for xss in SVG files.
1781                 # Expression and -o-link don't seem to work either, but filtering them here in case.
1782                 # Additionally, we catch remote urls like url("http:..., url('http:..., url(http:...,
1783                 # but not local ones such as url("#..., url('#..., url(#....
1784                 if ( preg_match( '!expression
1785                                 | -o-link\s*:
1786                                 | -o-link-source\s*:
1787                                 | -o-replace\s*:!imx', $value ) ) {
1788                         return true;
1789                 }
1790
1791                 if ( preg_match_all(
1792                                 "!(\s*(url|image|image-set)\s*\(\s*[\"']?\s*[^#]+.*?\))!sim",
1793                                 $value,
1794                                 $matches
1795                         ) !== 0
1796                 ) {
1797                         # TODO: redo this in one regex. Until then, url("#whatever") matches the first
1798                         foreach ( $matches[1] as $match ) {
1799                                 if ( !preg_match( "!\s*(url|image|image-set)\s*\(\s*(#|'#|\"#)!im", $match ) ) {
1800                                         return true;
1801                                 }
1802                         }
1803                 }
1804
1805                 if ( preg_match( '/[\000-\010\013\016-\037\177]/', $value ) ) {
1806                         return true;
1807                 }
1808
1809                 return false;
1810         }
1811
1812         /**
1813          * Divide the element name passed by the xml parser to the callback into URI and prifix.
1814          * @param string $element
1815          * @return array Containing the namespace URI and prefix
1816          */
1817         private static function splitXmlNamespace( $element ) {
1818                 // 'http://www.w3.org/2000/svg:script' -> [ 'http://www.w3.org/2000/svg', 'script' ]
1819                 $parts = explode( ':', strtolower( $element ) );
1820                 $name = array_pop( $parts );
1821                 $ns = implode( ':', $parts );
1822
1823                 return [ $ns, $name ];
1824         }
1825
1826         /**
1827          * @param string $name
1828          * @return string
1829          */
1830         private function stripXmlNamespace( $name ) {
1831                 // 'http://www.w3.org/2000/svg:script' -> 'script'
1832                 $parts = explode( ':', strtolower( $name ) );
1833
1834                 return array_pop( $parts );
1835         }
1836
1837         /**
1838          * Generic wrapper function for a virus scanner program.
1839          * This relies on the $wgAntivirus and $wgAntivirusSetup variables.
1840          * $wgAntivirusRequired may be used to deny upload if the scan fails.
1841          *
1842          * @param string $file Pathname to the temporary upload file
1843          * @return mixed False if not virus is found, null if the scan fails or is disabled,
1844          *   or a string containing feedback from the virus scanner if a virus was found.
1845          *   If textual feedback is missing but a virus was found, this function returns true.
1846          */
1847         public static function detectVirus( $file ) {
1848                 global $wgAntivirus, $wgAntivirusSetup, $wgAntivirusRequired, $wgOut;
1849
1850                 if ( !$wgAntivirus ) {
1851                         wfDebug( __METHOD__ . ": virus scanner disabled\n" );
1852
1853                         return null;
1854                 }
1855
1856                 if ( !$wgAntivirusSetup[$wgAntivirus] ) {
1857                         wfDebug( __METHOD__ . ": unknown virus scanner: $wgAntivirus\n" );
1858                         $wgOut->wrapWikiMsg( "<div class=\"error\">\n$1\n</div>",
1859                                 [ 'virus-badscanner', $wgAntivirus ] );
1860
1861                         return wfMessage( 'virus-unknownscanner' )->text() . " $wgAntivirus";
1862                 }
1863
1864                 # look up scanner configuration
1865                 $command = $wgAntivirusSetup[$wgAntivirus]['command'];
1866                 $exitCodeMap = $wgAntivirusSetup[$wgAntivirus]['codemap'];
1867                 $msgPattern = isset( $wgAntivirusSetup[$wgAntivirus]['messagepattern'] ) ?
1868                         $wgAntivirusSetup[$wgAntivirus]['messagepattern'] : null;
1869
1870                 if ( strpos( $command, "%f" ) === false ) {
1871                         # simple pattern: append file to scan
1872                         $command .= " " . wfEscapeShellArg( $file );
1873                 } else {
1874                         # complex pattern: replace "%f" with file to scan
1875                         $command = str_replace( "%f", wfEscapeShellArg( $file ), $command );
1876                 }
1877
1878                 wfDebug( __METHOD__ . ": running virus scan: $command \n" );
1879
1880                 # execute virus scanner
1881                 $exitCode = false;
1882
1883                 # NOTE: there's a 50 line workaround to make stderr redirection work on windows, too.
1884                 #      that does not seem to be worth the pain.
1885                 #      Ask me (Duesentrieb) about it if it's ever needed.
1886                 $output = wfShellExecWithStderr( $command, $exitCode );
1887
1888                 # map exit code to AV_xxx constants.
1889                 $mappedCode = $exitCode;
1890                 if ( $exitCodeMap ) {
1891                         if ( isset( $exitCodeMap[$exitCode] ) ) {
1892                                 $mappedCode = $exitCodeMap[$exitCode];
1893                         } elseif ( isset( $exitCodeMap["*"] ) ) {
1894                                 $mappedCode = $exitCodeMap["*"];
1895                         }
1896                 }
1897
1898                 /* NB: AV_NO_VIRUS is 0 but AV_SCAN_FAILED is false,
1899                  * so we need the strict equalities === and thus can't use a switch here
1900                  */
1901                 if ( $mappedCode === AV_SCAN_FAILED ) {
1902                         # scan failed (code was mapped to false by $exitCodeMap)
1903                         wfDebug( __METHOD__ . ": failed to scan $file (code $exitCode).\n" );
1904
1905                         $output = $wgAntivirusRequired
1906                                 ? wfMessage( 'virus-scanfailed', [ $exitCode ] )->text()
1907                                 : null;
1908                 } elseif ( $mappedCode === AV_SCAN_ABORTED ) {
1909                         # scan failed because filetype is unknown (probably imune)
1910                         wfDebug( __METHOD__ . ": unsupported file type $file (code $exitCode).\n" );
1911                         $output = null;
1912                 } elseif ( $mappedCode === AV_NO_VIRUS ) {
1913                         # no virus found
1914                         wfDebug( __METHOD__ . ": file passed virus scan.\n" );
1915                         $output = false;
1916                 } else {
1917                         $output = trim( $output );
1918
1919                         if ( !$output ) {
1920                                 $output = true; # if there's no output, return true
1921                         } elseif ( $msgPattern ) {
1922                                 $groups = [];
1923                                 if ( preg_match( $msgPattern, $output, $groups ) ) {
1924                                         if ( $groups[1] ) {
1925                                                 $output = $groups[1];
1926                                         }
1927                                 }
1928                         }
1929
1930                         wfDebug( __METHOD__ . ": FOUND VIRUS! scanner feedback: $output \n" );
1931                 }
1932
1933                 return $output;
1934         }
1935
1936         /**
1937          * Check if there's an overwrite conflict and, if so, if restrictions
1938          * forbid this user from performing the upload.
1939          *
1940          * @param User $user
1941          *
1942          * @return mixed True on success, array on failure
1943          */
1944         private function checkOverwrite( $user ) {
1945                 // First check whether the local file can be overwritten
1946                 $file = $this->getLocalFile();
1947                 $file->load( File::READ_LATEST );
1948                 if ( $file->exists() ) {
1949                         if ( !self::userCanReUpload( $user, $file ) ) {
1950                                 return [ 'fileexists-forbidden', $file->getName() ];
1951                         } else {
1952                                 return true;
1953                         }
1954                 }
1955
1956                 /* Check shared conflicts: if the local file does not exist, but
1957                  * wfFindFile finds a file, it exists in a shared repository.
1958                  */
1959                 $file = wfFindFile( $this->getTitle(), [ 'latest' => true ] );
1960                 if ( $file && !$user->isAllowed( 'reupload-shared' ) ) {
1961                         return [ 'fileexists-shared-forbidden', $file->getName() ];
1962                 }
1963
1964                 return true;
1965         }
1966
1967         /**
1968          * Check if a user is the last uploader
1969          *
1970          * @param User $user
1971          * @param File $img
1972          * @return bool
1973          */
1974         public static function userCanReUpload( User $user, File $img ) {
1975                 if ( $user->isAllowed( 'reupload' ) ) {
1976                         return true; // non-conditional
1977                 } elseif ( !$user->isAllowed( 'reupload-own' ) ) {
1978                         return false;
1979                 }
1980
1981                 if ( !( $img instanceof LocalFile ) ) {
1982                         return false;
1983                 }
1984
1985                 $img->load();
1986
1987                 return $user->getId() == $img->getUser( 'id' );
1988         }
1989
1990         /**
1991          * Helper function that does various existence checks for a file.
1992          * The following checks are performed:
1993          * - The file exists
1994          * - Article with the same name as the file exists
1995          * - File exists with normalized extension
1996          * - The file looks like a thumbnail and the original exists
1997          *
1998          * @param File $file The File object to check
1999          * @return mixed False if the file does not exists, else an array
2000          */
2001         public static function getExistsWarning( $file ) {
2002                 if ( $file->exists() ) {
2003                         return [ 'warning' => 'exists', 'file' => $file ];
2004                 }
2005
2006                 if ( $file->getTitle()->getArticleID() ) {
2007                         return [ 'warning' => 'page-exists', 'file' => $file ];
2008                 }
2009
2010                 if ( strpos( $file->getName(), '.' ) == false ) {
2011                         $partname = $file->getName();
2012                         $extension = '';
2013                 } else {
2014                         $n = strrpos( $file->getName(), '.' );
2015                         $extension = substr( $file->getName(), $n + 1 );
2016                         $partname = substr( $file->getName(), 0, $n );
2017                 }
2018                 $normalizedExtension = File::normalizeExtension( $extension );
2019
2020                 if ( $normalizedExtension != $extension ) {
2021                         // We're not using the normalized form of the extension.
2022                         // Normal form is lowercase, using most common of alternate
2023                         // extensions (eg 'jpg' rather than 'JPEG').
2024
2025                         // Check for another file using the normalized form...
2026                         $nt_lc = Title::makeTitle( NS_FILE, "{$partname}.{$normalizedExtension}" );
2027                         $file_lc = wfLocalFile( $nt_lc );
2028
2029                         if ( $file_lc->exists() ) {
2030                                 return [
2031                                         'warning' => 'exists-normalized',
2032                                         'file' => $file,
2033                                         'normalizedFile' => $file_lc
2034                                 ];
2035                         }
2036                 }
2037
2038                 // Check for files with the same name but a different extension
2039                 $similarFiles = RepoGroup::singleton()->getLocalRepo()->findFilesByPrefix(
2040                         "{$partname}.", 1 );
2041                 if ( count( $similarFiles ) ) {
2042                         return [
2043                                 'warning' => 'exists-normalized',
2044                                 'file' => $file,
2045                                 'normalizedFile' => $similarFiles[0],
2046                         ];
2047                 }
2048
2049                 if ( self::isThumbName( $file->getName() ) ) {
2050                         # Check for filenames like 50px- or 180px-, these are mostly thumbnails
2051                         $nt_thb = Title::newFromText(
2052                                 substr( $partname, strpos( $partname, '-' ) + 1 ) . '.' . $extension,
2053                                 NS_FILE
2054                         );
2055                         $file_thb = wfLocalFile( $nt_thb );
2056                         if ( $file_thb->exists() ) {
2057                                 return [
2058                                         'warning' => 'thumb',
2059                                         'file' => $file,
2060                                         'thumbFile' => $file_thb
2061                                 ];
2062                         } else {
2063                                 // File does not exist, but we just don't like the name
2064                                 return [
2065                                         'warning' => 'thumb-name',
2066                                         'file' => $file,
2067                                         'thumbFile' => $file_thb
2068                                 ];
2069                         }
2070                 }
2071
2072                 foreach ( self::getFilenamePrefixBlacklist() as $prefix ) {
2073                         if ( substr( $partname, 0, strlen( $prefix ) ) == $prefix ) {
2074                                 return [
2075                                         'warning' => 'bad-prefix',
2076                                         'file' => $file,
2077                                         'prefix' => $prefix
2078                                 ];
2079                         }
2080                 }
2081
2082                 return false;
2083         }
2084
2085         /**
2086          * Helper function that checks whether the filename looks like a thumbnail
2087          * @param string $filename
2088          * @return bool
2089          */
2090         public static function isThumbName( $filename ) {
2091                 $n = strrpos( $filename, '.' );
2092                 $partname = $n ? substr( $filename, 0, $n ) : $filename;
2093
2094                 return (
2095                         substr( $partname, 3, 3 ) == 'px-' ||
2096                         substr( $partname, 2, 3 ) == 'px-'
2097                 ) &&
2098                 preg_match( "/[0-9]{2}/", substr( $partname, 0, 2 ) );
2099         }
2100
2101         /**
2102          * Get a list of blacklisted filename prefixes from [[MediaWiki:Filename-prefix-blacklist]]
2103          *
2104          * @return array List of prefixes
2105          */
2106         public static function getFilenamePrefixBlacklist() {
2107                 $blacklist = [];
2108                 $message = wfMessage( 'filename-prefix-blacklist' )->inContentLanguage();
2109                 if ( !$message->isDisabled() ) {
2110                         $lines = explode( "\n", $message->plain() );
2111                         foreach ( $lines as $line ) {
2112                                 // Remove comment lines
2113                                 $comment = substr( trim( $line ), 0, 1 );
2114                                 if ( $comment == '#' || $comment == '' ) {
2115                                         continue;
2116                                 }
2117                                 // Remove additional comments after a prefix
2118                                 $comment = strpos( $line, '#' );
2119                                 if ( $comment > 0 ) {
2120                                         $line = substr( $line, 0, $comment - 1 );
2121                                 }
2122                                 $blacklist[] = trim( $line );
2123                         }
2124                 }
2125
2126                 return $blacklist;
2127         }
2128
2129         /**
2130          * Gets image info about the file just uploaded.
2131          *
2132          * Also has the effect of setting metadata to be an 'indexed tag name' in
2133          * returned API result if 'metadata' was requested. Oddly, we have to pass
2134          * the "result" object down just so it can do that with the appropriate
2135          * format, presumably.
2136          *
2137          * @param ApiResult $result
2138          * @return array Image info
2139          */
2140         public function getImageInfo( $result ) {
2141                 $localFile = $this->getLocalFile();
2142                 $stashFile = $this->getStashFile();
2143                 // Calling a different API module depending on whether the file was stashed is less than optimal.
2144                 // In fact, calling API modules here at all is less than optimal. Maybe it should be refactored.
2145                 if ( $stashFile ) {
2146                         $imParam = ApiQueryStashImageInfo::getPropertyNames();
2147                         $info = ApiQueryStashImageInfo::getInfo( $stashFile, array_flip( $imParam ), $result );
2148                 } else {
2149                         $imParam = ApiQueryImageInfo::getPropertyNames();
2150                         $info = ApiQueryImageInfo::getInfo( $localFile, array_flip( $imParam ), $result );
2151                 }
2152
2153                 return $info;
2154         }
2155
2156         /**
2157          * @param array $error
2158          * @return Status
2159          */
2160         public function convertVerifyErrorToStatus( $error ) {
2161                 $code = $error['status'];
2162                 unset( $code['status'] );
2163
2164                 return Status::newFatal( $this->getVerificationErrorCode( $code ), $error );
2165         }
2166
2167         /**
2168          * Get the MediaWiki maximum uploaded file size for given type of upload, based on
2169          * $wgMaxUploadSize.
2170          *
2171          * @param null|string $forType
2172          * @return int
2173          */
2174         public static function getMaxUploadSize( $forType = null ) {
2175                 global $wgMaxUploadSize;
2176
2177                 if ( is_array( $wgMaxUploadSize ) ) {
2178                         if ( !is_null( $forType ) && isset( $wgMaxUploadSize[$forType] ) ) {
2179                                 return $wgMaxUploadSize[$forType];
2180                         } else {
2181                                 return $wgMaxUploadSize['*'];
2182                         }
2183                 } else {
2184                         return intval( $wgMaxUploadSize );
2185                 }
2186         }
2187
2188         /**
2189          * Get the PHP maximum uploaded file size, based on ini settings. If there is no limit or the
2190          * limit can't be guessed, returns a very large number (PHP_INT_MAX).
2191          *
2192          * @since 1.27
2193          * @return int
2194          */
2195         public static function getMaxPhpUploadSize() {
2196                 $phpMaxFileSize = wfShorthandToInteger(
2197                         ini_get( 'upload_max_filesize' ) ?: ini_get( 'hhvm.server.upload.upload_max_file_size' ),
2198                         PHP_INT_MAX
2199                 );
2200                 $phpMaxPostSize = wfShorthandToInteger(
2201                         ini_get( 'post_max_size' ) ?: ini_get( 'hhvm.server.max_post_size' ),
2202                         PHP_INT_MAX
2203                 ) ?: PHP_INT_MAX;
2204                 return min( $phpMaxFileSize, $phpMaxPostSize );
2205         }
2206
2207         /**
2208          * Get the current status of a chunked upload (used for polling)
2209          *
2210          * The value will be read from cache.
2211          *
2212          * @param User $user
2213          * @param string $statusKey
2214          * @return Status[]|bool
2215          */
2216         public static function getSessionStatus( User $user, $statusKey ) {
2217                 $cache = MediaWikiServices::getInstance()->getMainObjectStash();
2218                 $key = $cache->makeKey( 'uploadstatus', $user->getId() ?: md5( $user->getName() ), $statusKey );
2219
2220                 return $cache->get( $key );
2221         }
2222
2223         /**
2224          * Set the current status of a chunked upload (used for polling)
2225          *
2226          * The value will be set in cache for 1 day
2227          *
2228          * @param User $user
2229          * @param string $statusKey
2230          * @param array|bool $value
2231          * @return void
2232          */
2233         public static function setSessionStatus( User $user, $statusKey, $value ) {
2234                 $cache = MediaWikiServices::getInstance()->getMainObjectStash();
2235                 $key = $cache->makeKey( 'uploadstatus', $user->getId() ?: md5( $user->getName() ), $statusKey );
2236
2237                 if ( $value === false ) {
2238                         $cache->delete( $key );
2239                 } else {
2240                         $cache->set( $key, $value, $cache::TTL_DAY );
2241                 }
2242         }
2243 }