📄 util.php

<?php
/*
 * FCKeditor - The text editor for Internet - http://www.fckeditor.net
 * Copyright (C) 2003-2010 Frederico Caldeira Knabben
 *
 * == BEGIN LICENSE ==
 *
 * Licensed under the terms of any of the following licenses at your
 * choice:
 *
 *  - GNU General Public License Version 2 or later (the "GPL")
 *    http://www.gnu.org/licenses/gpl.html
 *
 *  - GNU Lesser General Public License Version 2.1 or later (the "LGPL")
 *    http://www.gnu.org/licenses/lgpl.html
 *
 *  - Mozilla Public License Version 1.1 or later (the "MPL")
 *    http://www.mozilla.org/MPL/MPL-1.1.html
 *
 * == END LICENSE ==
 *
 * Utility functions for the File Manager Connector for PHP.
 */

/**
 * RemoveFromStart
 *
 * @param 	string		$sourceString	Source
 * @param 	string		$charToRemove	Char to remove
 * @return	string		Result
 */
function RemoveFromStart($sourceString, $charToRemove)
{
	$sPattern = '|^' . $charToRemove . '+|' ;
	return preg_replace($sPattern, '', $sourceString);
}

/**
 * RemoveFromEnd
 *
 * @param 	string		$sourceString	Source
 * @param 	string		$charToRemove	Rhar to remove
 * @return	string		Result
 */
function RemoveFromEnd($sourceString, $charToRemove)
{
	$sPattern = '|' . $charToRemove . '+$|' ;
	return preg_replace($sPattern, '', $sourceString);
}

/**
 * FindBadUtf8
 *
 * @param 	string $string		String
 * @return	boolean
 */
function FindBadUtf8($string)
{
	$regex = '([\x00-\x7F]'.
	'|[\xC2-\xDF][\x80-\xBF]'.
	'|\xE0[\xA0-\xBF][\x80-\xBF]'.
	'|[\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}'.
	'|\xED[\x80-\x9F][\x80-\xBF]'.
	'|\xF0[\x90-\xBF][\x80-\xBF]{2}'.
	'|[\xF1-\xF3][\x80-\xBF]{3}'.
	'|\xF4[\x80-\x8F][\x80-\xBF]{2}'.
	'|(.{1}))';

	while (preg_match('/'.$regex.'/S', $string, $matches)) {
		if ( isset($matches[2])) {
			return true;
		}
		$string = substr($string, strlen($matches[0]));
	}

	return false;
}

/**
 * ConvertToXmlAttribute
 *
 * @param 	string		$value		Value
 * @return	string
 */
function ConvertToXmlAttribute( $value )
{
	if ( defined('PHP_OS') )
	{
		$os = PHP_OS ;
	}
	else
	{
		$os = php_uname();
	}

	if (strtoupper(substr($os, 0, 3)) === 'WIN' || FindBadUtf8($value))
	{
		return (utf8_encode(htmlspecialchars($value)));
	}
	else
	{
		return (htmlspecialchars($value));
	}
}

/**
 * Check whether given extension is in html etensions list
 *
 * @param 	string 		$ext				Extension
 * @param 	array 		$formExtensions		Array of extensions
 * @return 	boolean
 */
function IsHtmlExtension( $ext, $formExtensions )
{
	if (!$formExtensions || !is_array($formExtensions) )
	{
		return false ;
	}
	$lcaseHtmlExtensions = array();
	foreach ( $formExtensions as $key => $val )
	{
		$lcaseHtmlExtensions[$key] = strtolower($val);
	}
	return in_array($ext, $lcaseHtmlExtensions);
}

/**
 * Detect HTML in the first KB to prevent against potential security issue with
 * IE/Safari/Opera file type auto detection bug.
 * Returns true if file contain insecure HTML code at the beginning.
 *
 * @param string $filePath absolute path to file
 * @return boolean
 */
function DetectHtml( $filePath )
{
	$fp = @fopen($filePath, 'rb');

	//open_basedir restriction, see #1906
	if ( $fp === false || !flock($fp, LOCK_SH) )
	{
		return -1 ;
	}

	$chunk = fread($fp, 1024);
	flock($fp, LOCK_UN);
	fclose($fp);

	$chunk = strtolower($chunk);

	if (!$chunk)
	{
		return false ;
	}

	$chunk = trim($chunk);

	if ( preg_match("/<!DOCTYPE\W*X?HTML/sim", $chunk) )
	{
		return true;
	}

	$tags = array( '<body', '<head', '<html', '<img', '<pre', '<script', '<table', '<title' );

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

	//type = javascript
	if ( preg_match('!type\s*=\s*[\'"]?\s*(?:\w*/)?(?:ecma|java)!sim', $chunk) )
	{
		return true ;
	}

	//href = javascript
	//src = javascript
	//data = javascript
	if ( preg_match('!(?:href|src|data)\s*=\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk) )
	{
		return true ;
	}

	//url(javascript
	if ( preg_match('!url\s*\(\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk) )
	{
		return true ;
	}

	return false ;
}

/**
 * Check file content.
 * Currently this function validates only image files.
 * Returns false if file is invalid.
 *
 * @param 	string 	$filePath 		Absolute path to file
 * @param 	string 	$extension 		File extension
 * @return 	boolean					True or false
 */
function IsImageValid( $filePath, $extension )
{
	if (!@is_readable($filePath)) {
		return -1;
	}

	$imageCheckExtensions = array(
        'gif',
        'jpeg',
        'jpg',
        'png',
        'swf',
        'psd',
        'bmp',
        'iff',
        'tiff',
        'tif',
        'swc',
        'jpc',
        'jp2',
        'jpx',
        'jb2',
        'xbm',
        'wbmp'
    );

	if (!in_array($extension, $imageCheckExtensions) ) {
		return true;
	}

	if (@getimagesize($filePath) === false) {
		return false ;
	}

	return true;
}