specialupload.php

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		return in_array( strtolower( $ext ), $list );
	}

	/**
	 * Perform case-insensitive match against a list of file extensions.
	 * Returns true if any of the extensions are in the list.
	 *
	 * @param array $ext
	 * @param array $list
	 * @return bool
	 */
	function checkFileExtensionList( $ext, $list ) {
		foreach( $ext as $e ) {
			if( in_array( strtolower( $e ), $list ) ) {
				return true;
			}
		}
		return false;
	}

	/**
	 * Verifies that it's ok to include the uploaded file
	 *
	 * @param string $tmpfile the full path of the temporary file to verify
	 * @param string $extension The filename extension that the file is to be served with
	 * @return mixed true of the file is verified, a WikiError object otherwise.
	 */
	function verify( $tmpfile, $extension ) {
		#magically determine mime type
		$magic=& wfGetMimeMagic();
		$mime= $magic->guessMimeType($tmpfile,false);

		$fname= "SpecialUpload::verify";

		#check mime type, if desired
		global $wgVerifyMimeType;
		if ($wgVerifyMimeType) {

			#check mime type against file extension
			if( !$this->verifyExtension( $mime, $extension ) ) {
				return new WikiErrorMsg( 'uploadcorrupt' );
			}

			#check mime type blacklist
			global $wgMimeTypeBlacklist;
			if( isset($wgMimeTypeBlacklist) && !is_null($wgMimeTypeBlacklist)
				&& $this->checkFileExtension( $mime, $wgMimeTypeBlacklist ) ) {
				return new WikiErrorMsg( 'badfiletype', htmlspecialchars( $mime ) );
			}
		}

		#check for htmlish code and javascript
		if( $this->detectScript ( $tmpfile, $mime, $extension ) ) {
			return new WikiErrorMsg( 'uploadscripted' );
		}

		/**
		* Scan the uploaded file for viruses
		*/
		$virus= $this->detectVirus($tmpfile);
		if ( $virus ) {
			return new WikiErrorMsg( 'uploadvirus', htmlspecialchars($virus) );
		}

		wfDebug( "$fname: all clear; passing.\n" );
		return true;
	}

	/**
	 * Checks if the mime type of the uploaded file matches the file extension.
	 *
	 * @param string $mime the mime type of the uploaded file
	 * @param string $extension The filename extension that the file is to be served with
	 * @return bool
	 */
	function verifyExtension( $mime, $extension ) {
		$fname = 'SpecialUpload::verifyExtension';

		$magic =& wfGetMimeMagic();

		if ( ! $mime || $mime == 'unknown' || $mime == 'unknown/unknown' )
			if ( ! $magic->isRecognizableExtension( $extension ) ) {
				wfDebug( "$fname: passing file with unknown detected mime type; unrecognized extension '$extension', can't verify\n" );
				return true;
			} else {
				wfDebug( "$fname: rejecting file with unknown detected mime type; recognized extension '$extension', so probably invalid file\n" );
				return false;
			}

		$match= $magic->isMatchingExtension($extension,$mime);

		if ($match===NULL) {
			wfDebug( "$fname: no file extension known for mime type $mime, passing file\n" );
			return true;
		} elseif ($match===true) {
			wfDebug( "$fname: mime type $mime matches extension $extension, passing file\n" );

			#TODO: if it's a bitmap, make sure PHP or ImageMagic resp. can handle it!
			return true;

		} else {
			wfDebug( "$fname: mime type $mime mismatches file extension $extension, rejecting file\n" );
			return false;
		}
	}

	/** Heuristig for detecting files that *could* contain JavaScript instructions or
	* things that may look like HTML to a browser and are thus
	* potentially harmful. The present implementation will produce false positives in some situations.
	*
	* @param string $file Pathname to the temporary upload file
	* @param string $mime The mime type of the file
	* @param string $extension The extension of the file
	* @return bool true if the file contains something looking like embedded scripts
	*/
	function detectScript($file, $mime, $extension) {
		global $wgAllowTitlesInSVG;

		#ugly hack: for text files, always look at the entire file.
		#For binarie field, just check the first K.

		if (strpos($mime,'text/')===0) $chunk = file_get_contents( $file );
		else {
			$fp = fopen( $file, 'rb' );
			$chunk = fread( $fp, 1024 );
			fclose( $fp );
		}

		$chunk= strtolower( $chunk );

		if (!$chunk) return false;

		#decode from UTF-16 if needed (could be used for obfuscation).
		if (substr($chunk,0,2)=="\xfe\xff") $enc= "UTF-16BE";
		elseif (substr($chunk,0,2)=="\xff\xfe") $enc= "UTF-16LE";
		else $enc= NULL;

		if ($enc) $chunk= iconv($enc,"ASCII//IGNORE",$chunk);

		$chunk= trim($chunk);

		#FIXME: convert from UTF-16 if necessarry!

		wfDebug("SpecialUpload::detectScript: checking for embedded scripts and HTML stuff\n");

		#check for HTML doctype
		if (eregi("<!DOCTYPE *X?HTML",$chunk)) return true;

		/**
		* Internet Explorer for Windows performs some really stupid file type
		* autodetection which can cause it to interpret valid image files as HTML
		* and potentially execute JavaScript, creating a cross-site scripting
		* attack vectors.
		*
		* Apple's Safari browser also performs some unsafe file type autodetection
		* which can cause legitimate files to be interpreted as HTML if the
		* web server is not correctly configured to send the right content-type
		* (or if you're really uploading plain text and octet streams!)
		*
		* Returns true if IE is likely to mistake the given file for HTML.
		* Also returns true if Safari would mistake the given file for HTML
		* when served with a generic content-type.
		*/

		$tags = array(
			'<body',
			'<head',
			'<html',   #also in safari
			'<img',
			'<pre',
			'<script', #also in safari
			'<table'
			);
		if( ! $wgAllowTitlesInSVG && $extension !== 'svg' && $mime !== 'image/svg' ) {
			$tags[] = '<title';
		}

		foreach( $tags as $tag ) {
			if( false !== strpos( $chunk, $tag ) ) {
				return true;
			}
		}

		/*
		* look for javascript
		*/

		#resolve entity-refs to look at attributes. may be harsh on big files... cache result?
		$chunk = Sanitizer::decodeCharReferences( $chunk );

		#look for script-types
		if (preg_match("!type\s*=\s*['\"]?\s*(\w*/)?(ecma|java)!sim",$chunk)) return true;

		#look for html-style script-urls
		if (preg_match("!(href|src|data)\s*=\s*['\"]?\s*(ecma|java)script:!sim",$chunk)) return true;

		#look for css-style script-urls
		if (preg_match("!url\s*\(\s*['\"]?\s*(ecma|java)script:!sim",$chunk)) return true;

		wfDebug("SpecialUpload::detectScript: no scripts found\n");
		return false;
	}

	/** Generic wrapper function for a virus scanner program.
	* This relies on the $wgAntivirus and $wgAntivirusSetup variables.
	* $wgAntivirusRequired may be used to deny upload if the scan fails.
	*
	* @param string $file Pathname to the temporary upload file
	* @return mixed false if not virus is found, NULL if the scan fails or is disabled,
	*         or a string containing feedback from the virus scanner if a virus was found.
	*         If textual feedback is missing but a virus was found, this function returns true.
	*/
	function detectVirus($file) {
		global $wgAntivirus, $wgAntivirusSetup, $wgAntivirusRequired, $wgOut;

		$fname= "SpecialUpload::detectVirus";

		if (!$wgAntivirus) { #disabled?
			wfDebug("$fname: virus scanner disabled\n");

			return NULL;
		}

		if (!$wgAntivirusSetup[$wgAntivirus]) {
			wfDebug("$fname: unknown virus scanner: $wgAntivirus\n");

			$wgOut->addHTML( "<div class='error'>Bad configuration: unknown virus scanner: <i>$wgAntivirus</i></div>\n" ); #LOCALIZE

			return "unknown antivirus: $wgAntivirus";
		}

		#look up scanner configuration
		$virus_scanner= $wgAntivirusSetup[$wgAntivirus]["command"]; #command pattern
		$virus_scanner_codes= $wgAntivirusSetup[$wgAntivirus]["codemap"]; #exit-code map
		$msg_pattern= $wgAntivirusSetup[$wgAntivirus]["messagepattern"]; #message pattern

		$scanner= $virus_scanner; #copy, so we can resolve the pattern

		if (strpos($scanner,"%f")===false) $scanner.= " ".wfEscapeShellArg($file); #simple pattern: append file to scan
		else $scanner= str_replace("%f",wfEscapeShellArg($file),$scanner); #complex pattern: replace "%f" with file to scan

		wfDebug("$fname: running virus scan: $scanner \n");

		#execute virus scanner
		$code= false;

		#NOTE: there's a 50 line workaround to make stderr redirection work on windows, too.
		#      that does not seem to be worth the pain.
		#      Ask me (Duesentrieb) about it if it's ever needed.
		if (wfIsWindows()) exec("$scanner",$output,$code);
		else exec("$scanner 2>&1",$output,$code);

		$exit_code= $code; #remeber for user feedback

		if ($virus_scanner_codes) { #map exit code to AV_xxx constants.
			if (isset($virus_scanner_codes[$code])) $code= $virus_scanner_codes[$code]; #explicite mapping
			else if (isset($virus_scanner_codes["*"])) $code= $virus_scanner_codes["*"]; #fallback mapping
		}

		if ($code===AV_SCAN_FAILED) { #scan failed (code was mapped to false by $virus_scanner_codes)
			wfDebug("$fname: failed to scan $file (code $exit_code).\n");

			if ($wgAntivirusRequired) return "scan failed (code $exit_code)";
			else return NULL;
		}
		else if ($code===AV_SCAN_ABORTED) { #scan failed because filetype is unknown (probably imune)
			wfDebug("$fname: unsupported file type $file (code $exit_code).\n");
			return NULL;
		}
		else if ($code===AV_NO_VIRUS) {
			wfDebug("$fname: file passed virus scan.\n");
			return false; #no virus found
		}
		else {
			$output= join("\n",$output);
			$output= trim($output);

			if (!$output) $output= true; #if ther's no output, return true
			else if ($msg_pattern) {
				$groups= array();
				if (preg_match($msg_pattern,$output,$groups)) {
					if ($groups[1]) $output= $groups[1];
				}
			}

			wfDebug("$fname: FOUND VIRUS! scanner feedback: $output");
			return $output;
		}
	}

	/**
	 * Check if the temporary file is MacBinary-encoded, as some uploads
	 * from Internet Explorer on Mac OS Classic and Mac OS X will be.
	 * If so, the data fork will be extracted to a second temporary file,
	 * which will then be checked for validity and either kept or discarded.
	 *
	 * @access private
	 */
	function checkMacBinary() {
		$macbin = new MacBinary( $this->mUploadTempName );
		if( $macbin->isValid() ) {
			$dataFile = tempnam( wfTempDir(), "WikiMacBinary" );
			$dataHandle = fopen( $dataFile, 'wb' );

			wfDebug( "SpecialUpload::checkMacBinary: Extracting MacBinary data fork to $dataFile\n" );
			$macbin->extractData( $dataHandle );

			$this->mUploadTempName = $dataFile;
			$this->mUploadSize = $macbin->dataForkLength();

			// We'll have to manually remove the new file if it's not kept.
			$this->mRemoveTempFile = true;
		}
		$macbin->close();
	}

	/**
	 * If we've modified the upload file we need to manually remove it
	 * on exit to clean up.
	 * @access private
	 */
	function cleanupTempFile() {
		if( $this->mRemoveTempFile && file_exists( $this->mUploadTempName ) ) {
			wfDebug( "SpecialUpload::cleanupTempFile: Removing temporary file $this->mUploadTempName\n" );
			unlink( $this->mUploadTempName );
		}
	}

	/**
	 * Check if there's an overwrite conflict and, if so, if restrictions
	 * forbid this user from performing the upload.
	 *
	 * @return mixed true on success, WikiError on failure
	 * @access private
	 */
	function checkOverwrite( $name ) {
		$img = Image::newFromName( $name );
		if( is_null( $img ) ) {
			// Uh... this shouldn't happen ;)
			// But if it does, fall through to previous behavior
			return false;
		}

		$error = '';
		if( $img->exists() ) {
			global $wgUser, $wgOut;
			if( $img->isLocal() ) {
				if( !$wgUser->isAllowed( 'reupload' ) ) {
					$error = 'fileexists-forbidden';
				}
			} else {
				if( !$wgUser->isAllowed( 'reupload' ) ||
				    !$wgUser->isAllowed( 'reupload-shared' ) ) {
					$error = "fileexists-shared-forbidden";
				}
			}
		}

		if( $error ) {
			$errorText = wfMsg( $error, wfEscapeWikiText( $img->getName() ) );
			return new WikiError( $wgOut->parse( $errorText ) );
		}

		// Rockin', go ahead and upload
		return true;
	}

}
?>