<?php
/** @class: InputFilter (PHP4 & PHP5, without comments)
  * @project: PHP Input Filter
  * @date: 10-05-2005
  * @version: 1.2.2_php4/php5
  * @author: Daniel Morris
  * @contributors: Gianpaolo Racca, Ghislain Picard, Marco Wandschneider, Chris Tobin and Andrew Eddie.
  * @copyright: Daniel Morris
  * @email: dan@rootcube.com
  * @license: GNU General Public License (GPL)
  */
class InputFilter {
	var $tagsArray;
	var $attrArray;
	var $tagsMethod;
	var $attrMethod;
	var $xssAuto;
	var $tagBlacklist = array('applet', 'body', 'bgsound', 'base', 'basefont', 'embed', 'frame', 'frameset', 'head', 'html', 'id', 'iframe', 'ilayer', 'layer', 'link', 'meta', 'name', 'object', 'script', 'style', 'title', 'xml');
	var $attrBlacklist = array('action', 'background', 'codebase', 'dynsrc', 'lowsrc');
	function inputFilter($tagsArray = array(), $attrArray = array(), $tagsMethod = 0, $attrMethod = 0, $xssAuto = 1) {		
		for ($i = 0; $i < count($tagsArray); $i++) $tagsArray[$i] = strtolower($tagsArray[$i]);
		for ($i = 0; $i < count($attrArray); $i++) $attrArray[$i] = strtolower($attrArray[$i]);
		$this->tagsArray = (array) $tagsArray;
		$this->attrArray = (array) $attrArray;
		$this->tagsMethod = $tagsMethod;
		$this->attrMethod = $attrMethod;
		$this->xssAuto = $xssAuto;
	}
	function process($source) {
		if (is_array($source)) {
			foreach($source as $key => $value)
				if (is_string($value)) $source[$key] = $this->remove($this->decode($value));
			return $source;
		} else if (is_string($source)) {
			return $this->remove($this->decode($source));
		} else return $source;	
	}
	function remove($source) {
		$loopCounter=0;
		while($source != $this->filterTags($source)) {
			$source = $this->filterTags($source);
			$loopCounter++;
		}
		return $source;
	}	
	function filterTags($source) {
		$preTag = NULL;
		$postTag = $source;
		$tagOpen_start = strpos($source, '<');
		while($tagOpen_start !== FALSE) {
			$preTag .= substr($postTag, 0, $tagOpen_start);
			$postTag = substr($postTag, $tagOpen_start);
			$fromTagOpen = substr($postTag, 1);
			$tagOpen_end = strpos($fromTagOpen, '>');
			if ($tagOpen_end === false) break;
			$tagOpen_nested = strpos($fromTagOpen, '<');
			if (($tagOpen_nested !== false) && ($tagOpen_nested < $tagOpen_end)) {
				$preTag .= substr($postTag, 0, ($tagOpen_nested+1));
				$postTag = substr($postTag, ($tagOpen_nested+1));
				$tagOpen_start = strpos($postTag, '<');
				continue;
			} 
			$tagOpen_nested = (strpos($fromTagOpen, '<') + $tagOpen_start + 1);
			$currentTag = substr($fromTagOpen, 0, $tagOpen_end);
			$tagLength = strlen($currentTag);
			if (!$tagOpen_end) {
				$preTag .= $postTag;
				$tagOpen_start = strpos($postTag, '<');			
			}
			$tagLeft = $currentTag;
			$attrSet = array();
			$currentSpace = strpos($tagLeft, ' ');
			if (substr($currentTag, 0, 1) == "/") {
				$isCloseTag = TRUE;
				list($tagName) = explode(' ', $currentTag);
				$tagName = substr($tagName, 1);
			} else {
				$isCloseTag = FALSE;
				list($tagName) = explode(' ', $currentTag);
			}		
			if ((!preg_match("/^[a-z][a-z0-9]*$/i",$tagName)) || (!$tagName) || ((in_array(strtolower($tagName), $this->tagBlacklist)) && ($this->xssAuto))) { 				
				$postTag = substr($postTag, ($tagLength + 2));
				$tagOpen_start = strpos($postTag, '<');
				continue;
			}
			while ($currentSpace !== FALSE) {
				$fromSpace = substr($tagLeft, ($currentSpace+1));
				$nextSpace = strpos($fromSpace, ' ');
				$openQuotes = strpos($fromSpace, '"');
				$closeQuotes = strpos(substr($fromSpace, ($openQuotes+1)), '"') + $openQuotes + 1;
				if (strpos($fromSpace, '=') !== FALSE) {
					if (($openQuotes !== FALSE) && (strpos(substr($fromSpace, ($openQuotes+1)), '"') !== FALSE))
						$attr = substr($fromSpace, 0, ($closeQuotes+1));
					else $attr = substr($fromSpace, 0, $nextSpace);
				} else $attr = substr($fromSpace, 0, $nextSpace);
				if (!$attr) $attr = $fromSpace;
				$attrSet[] = $attr;
				$tagLeft = substr($fromSpace, strlen($attr));
				$currentSpace = strpos($tagLeft, ' ');
			}
			$tagFound = in_array(strtolower($tagName), $this->tagsArray);			
			if ((!$tagFound && $this->tagsMethod) || ($tagFound && !$this->tagsMethod)) {
				if (!$isCloseTag) {
					$attrSet = $this->filterAttr($attrSet);
					$preTag .= '<' . $tagName;
					for ($i = 0; $i < count($attrSet); $i++)
						$preTag .= ' ' . $attrSet[$i];
					if (strpos($fromTagOpen, "</" . $tagName)) $preTag .= '>';
					else $preTag .= ' />';
			    } else $preTag .= '</' . $tagName . '>';
			}
			$postTag = substr($postTag, ($tagLength + 2));
			$tagOpen_start = strpos($postTag, '<');			
		}
		$preTag .= $postTag;
		return $preTag;
	}
	function filterAttr($attrSet) {	
		$newSet = array();
		for ($i = 0; $i <count($attrSet); $i++) {
			if (!$attrSet[$i]) continue;
			$attrSubSet = explode('=', trim($attrSet[$i]));
			list($attrSubSet[0]) = explode(' ', $attrSubSet[0]);
			if ((!eregi("^[a-z]*$",$attrSubSet[0])) || (($this->xssAuto) && ((in_array(strtolower($attrSubSet[0]), $this->attrBlacklist)) || (substr($attrSubSet[0], 0, 2) == 'on')))) 
				continue;
			if ($attrSubSet[1]) {
				$attrSubSet[1] = str_replace('&#', '', $attrSubSet[1]);
				$attrSubSet[1] = preg_replace('/\s+/', '', $attrSubSet[1]);
				$attrSubSet[1] = str_replace('"', '', $attrSubSet[1]);
				if ((substr($attrSubSet[1], 0, 1) == "'") && (substr($attrSubSet[1], (strlen($attrSubSet[1]) - 1), 1) == "'"))
					$attrSubSet[1] = substr($attrSubSet[1], 1, (strlen($attrSubSet[1]) - 2));
				$attrSubSet[1] = stripslashes($attrSubSet[1]);
			}
			if (	((strpos(strtolower($attrSubSet[1]), 'expression') !== false) &&	(strtolower($attrSubSet[0]) == 'style')) ||
					(strpos(strtolower($attrSubSet[1]), 'javascript:') !== false) ||
					(strpos(strtolower($attrSubSet[1]), 'behaviour:') !== false) ||
					(strpos(strtolower($attrSubSet[1]), 'vbscript:') !== false) ||
					(strpos(strtolower($attrSubSet[1]), 'mocha:') !== false) ||
					(strpos(strtolower($attrSubSet[1]), 'livescript:') !== false) 
			) continue;
			$attrFound = in_array(strtolower($attrSubSet[0]), $this->attrArray);
			if ((!$attrFound && $this->attrMethod) || ($attrFound && !$this->attrMethod)) {
				if ($attrSubSet[1]) $newSet[] = $attrSubSet[0] . '="' . $attrSubSet[1] . '"';
				else if ($attrSubSet[1] == "0") $newSet[] = $attrSubSet[0] . '="0"';
				else $newSet[] = $attrSubSet[0] . '="' . $attrSubSet[0] . '"';
			}	
		}
		return $newSet;
	}
	function decode($source) {
		$source = html_entity_decode($source, ENT_QUOTES, "ISO-8859-1");
		$source = preg_replace('/&#(\d+);/me',"chr(\\1)", $source);
		$source = preg_replace('/&#x([a-f0-9]+);/mei',"chr(0x\\1)", $source);
		return $source;
	}
	function safeSQL($source, &$connection) {
		if (is_array($source)) {
			foreach($source as $key => $value)
				if (is_string($value)) $source[$key] = $this->quoteSmart($this->decode($value), $connection);
			return $source;
		} else if (is_string($source)) {
			if (is_string($source)) return $this->quoteSmart($this->decode($source), $connection);
		} else return $source;	
	}
	function quoteSmart($source, &$connection) {
		if (get_magic_quotes_gpc()) $source = stripslashes($source);
		$source = $this->escapeString($source, $connection);
		return $source;
	}
	function escapeString($string, &$connection) {
		if (version_compare(phpversion(),"4.3.0", "<")) mysql_escape_string($string);
		else mysql_real_escape_string($string);
		return $string;
	}
}
?>