xss过滤函数

Posted 2020-06-13

XSS是一种经常出现在web应用中的计算机安全漏洞，它允许恶意web用户将代码植入到提供给其它用户使用的页面中。

比如这些代码包括html代码和客户端脚本。

        function remove_xss($string) {  
            $string = preg_replace(‘/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]+/S‘, ‘‘, $string); 
         
            $parm1 = Array(‘javascript‘, ‘vbscript‘, ‘expression‘, ‘applet‘, ‘meta‘, ‘xml‘, ‘blink‘, ‘link‘, 
‘script‘, ‘embed‘, ‘object‘, ‘iframe‘, ‘frame‘, ‘frameset‘, ‘ilayer‘, ‘layer‘, ‘bgsound‘, ‘title‘, ‘base‘); 
         
            $parm2 = Array(‘onabort‘, ‘onactivate‘, ‘onafterprint‘, ‘onafterupdate‘, ‘onbeforeactivate‘,
 ‘onbeforecopy‘, ‘onbeforecut‘, ‘onbeforedeactivate‘, ‘onbeforeeditfocus‘, ‘onbeforepaste‘, ‘onbeforeprint‘, 
‘onbeforeunload‘, ‘onbeforeupdate‘, ‘onblur‘, ‘onbounce‘, ‘oncellchange‘, ‘onchange‘, ‘onclick‘, ‘oncontextmenu‘,
 ‘oncontrolselect‘, ‘oncopy‘, ‘oncut‘, ‘ondataavailable‘, ‘ondatasetchanged‘, ‘ondatasetcomplete‘, ‘ondblclick‘,
 ‘ondeactivate‘, ‘ondrag‘, ‘ondragend‘, ‘ondragenter‘, ‘ondragleave‘, ‘ondragover‘, ‘ondragstart‘, ‘ondrop‘,
 ‘onerror‘, ‘onerrorupdate‘, ‘onfilterchange‘, ‘onfinish‘, ‘onfocus‘, ‘onfocusin‘, ‘onfocusout‘, ‘onhelp‘,
 ‘onkeydown‘, ‘onkeypress‘, ‘onkeyup‘, ‘onlayoutcomplete‘, ‘onload‘, ‘onlosecapture‘, ‘onmousedown‘,
 ‘onmouseenter‘, ‘onmouseleave‘, ‘onmousemove‘, ‘onmouseout‘, ‘onmouseover‘, ‘onmouseup‘, ‘onmousewheel‘, 
‘onmove‘, ‘onmoveend‘, ‘onmovestart‘, ‘onpaste‘, ‘onpropertychange‘, ‘onreadystatechange‘, ‘onreset‘, ‘onresize‘,
 ‘onresizeend‘, ‘onresizestart‘, ‘onrowenter‘, ‘onrowexit‘, ‘onrowsdelete‘, ‘onrowsinserted‘, ‘onscroll‘, ‘onselect‘,
 ‘onselectionchange‘, ‘onselectstart‘, ‘onstart‘, ‘onstop‘, ‘onsubmit‘, ‘onunload‘); 
         
            $parm = array_merge($parm1, $parm2);  
         
            for ($i = 0; $i < sizeof($parm); $i++) {  
                $pattern = ‘/‘;  
                for ($j = 0; $j < strlen($parm[$i]); $j++) {  
                    if ($j > 0) {  
                        $pattern .= ‘(‘;  
                        $pattern .= ‘(&#[x|X]0([9][a][b]);?)?‘;  
                        $pattern .= ‘|(&#0([9][10][13]);?)?‘;  
                        $pattern .= ‘)?‘;  
                    } 
                    $pattern .= $parm[$i][$j];  
                } 
                $pattern .= ‘/i‘; 
                $string = preg_replace($pattern, ‘ ‘, $string);  
            } 
            return $string; 
        }