<?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")
 *    https://www.gnu.org/licenses/gpl.html
 *
 *  - GNU Lesser General Public License Version 2.1 or later (the "LGPL")
 *    https://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]';
	$regex .= '|\xF0[\x90-\xBF][\x80-\xBF]{2}|[\xF1-\xF3][\x80-\xBF]{3}|\xF4[\x80-\x8F][\x80-\xBF]{2}|(.{1}))';

	$matches = array();
	while (preg_match('/'.$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;
}
