170 lines
4.5 KiB
PHP
170 lines
4.5 KiB
PHP
<?php
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/**
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* PHP 富文本XSS过滤类
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*
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* @package XssHtml
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* @version 1.0.0
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* @link http://phith0n.github.io/XssHtml
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* @since 20140621
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* @copyright (c) Phithon All Rights Reserved
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*
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*/
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class XssHtml {
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private $m_dom;
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private $m_xss;
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private $m_ok;
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private $m_AllowAttr = array('title', 'src', 'href', 'id', 'class', 'style', 'width', 'height', 'alt', 'target', 'align');
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private $m_AllowTag = array('a', 'img', 'br', 'strong', 'b', 'code', 'pre', 'p', 'div', 'em', 'span', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'table', 'ul', 'ol', 'tr', 'th', 'td', 'hr', 'li', 'u');
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/**
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* 构造函数
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*
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* @param string $html 待过滤的文本
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* @param string $charset 文本编码，默认utf-8
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* @param array $AllowTag 允许的标签，如果不清楚请保持默认，默认已涵盖大部分功能，不要增加危险标签
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*/
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public function __construct($html, $charset = 'utf-8', $AllowTag = array()){
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$this->m_AllowTag = empty($AllowTag) ? $this->m_AllowTag : $AllowTag;
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$this->m_xss = strip_tags($html, '<' . implode('><', $this->m_AllowTag) . '>');
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if (empty($this->m_xss)) {
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$this->m_ok = FALSE;
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return ;
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}
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$this->m_xss = "<meta http-equiv=\"Content-Type\" content=\"text/html;charset={$charset}\"><nouse>" . $this->m_xss . "</nouse>";
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$this->m_dom = new DOMDocument();
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$this->m_dom->strictErrorChecking = FALSE;
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$this->m_ok = @$this->m_dom->loadHTML($this->m_xss);
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}
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/**
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* 获得过滤后的内容
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*/
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public function getHtml()
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{
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if (!$this->m_ok) {
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return '';
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}
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$nodeList = $this->m_dom->getElementsByTagName('*');
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for ($i = 0; $i < $nodeList->length; $i++){
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$node = $nodeList->item($i);
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if (in_array($node->nodeName, $this->m_AllowTag)) {
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if (method_exists($this, "__node_{$node->nodeName}")) {
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call_user_func(array($this, "__node_{$node->nodeName}"), $node);
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}else{
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call_user_func(array($this, '__node_default'), $node);
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}
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}
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}
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$html = strip_tags($this->m_dom->saveHTML(), '<' . implode('><', $this->m_AllowTag) . '>');
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$html = preg_replace('/^\n(.*)\n$/s', '$1', $html);
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return $html;
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}
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private function __true_url($url){
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if (preg_match('#^https?://.+#is', $url)) {
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return $url;
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}else{
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return 'http://' . $url;
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}
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}
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private function __get_style($node){
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if ($node->attributes->getNamedItem('style')) {
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$style = $node->attributes->getNamedItem('style')->nodeValue;
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$style = str_replace('\\', ' ', $style);
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$style = str_replace(array('&#', '/*', '*/'), ' ', $style);
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$style = preg_replace('#e.*x.*p.*r.*e.*s.*s.*i.*o.*n#Uis', ' ', $style);
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return $style;
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}else{
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return '';
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}
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}
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private function __get_link($node, $att){
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$link = $node->attributes->getNamedItem($att);
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if ($link) {
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return $this->__true_url($link->nodeValue);
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}else{
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return '';
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}
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}
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private function __setAttr($dom, $attr, $val){
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if (!empty($val)) {
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$dom->setAttribute($attr, $val);
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}
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}
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private function __set_default_attr($node, $attr, $default = '')
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{
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$o = $node->attributes->getNamedItem($attr);
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if ($o) {
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$this->__setAttr($node, $attr, $o->nodeValue);
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}else{
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$this->__setAttr($node, $attr, $default);
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}
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}
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private function __common_attr($node)
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{
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$list = array();
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foreach ($node->attributes as $attr) {
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if (!in_array($attr->nodeName,
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$this->m_AllowAttr)) {
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$list[] = $attr->nodeName;
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}
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}
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foreach ($list as $attr) {
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$node->removeAttribute($attr);
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}
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$style = $this->__get_style($node);
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$this->__setAttr($node, 'style', $style);
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$this->__set_default_attr($node, 'title');
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$this->__set_default_attr($node, 'id');
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$this->__set_default_attr($node, 'class');
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}
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private function __node_img($node){
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$this->__common_attr($node);
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$this->__set_default_attr($node, 'src');
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$this->__set_default_attr($node, 'width');
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$this->__set_default_attr($node, 'height');
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$this->__set_default_attr($node, 'alt');
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$this->__set_default_attr($node, 'align');
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}
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private function __node_a($node){
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$this->__common_attr($node);
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$href = $this->__get_link($node, 'href');
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$this->__setAttr($node, 'href', $href);
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$this->__set_default_attr($node, 'target', '_blank');
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}
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private function __node_embed($node){
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$this->__common_attr($node);
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$link = $this->__get_link($node, 'src');
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$this->__setAttr($node, 'src', $link);
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$this->__setAttr($node, 'allowscriptaccess', 'never');
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$this->__set_default_attr($node, 'width');
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$this->__set_default_attr($node, 'height');
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}
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private function __node_default($node){
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$this->__common_attr($node);
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}
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}
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function waf($data)
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{
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$xss = new XssHtml($data);
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$html = $xss->getHtml();
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echo $html;
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}
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?>
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