replace防注入的方法(2)

    <?php
    function RemoveXSS($val) {
       // remove all non-printable characters. CR(0a) and LF(0b) and TAB(9) are allowed
       // this prevents some character re-spacing such as <javascript>
       // note that you have to handle splits with , , and later since they *are* allowed in some          // inputs
       $val = preg_replace('/([x00-x08,x0b-x0c,x0e-x19])/', '', $val);
       // straight replacements, the user should never need these since they're normal characters
       // this prevents like <IMG SRC=https://www.jb51.net/@avascript:alert('XSS')>
       $search = 'abcdefghijklmnopqrstuvwxyz';
       $search .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
       $search .= '1234567890!@#$%^&*()';
       $search .= '~`";:?+/={}[]-_|'';
       for ($i = 0; $i < strlen($search); $i++) {
           // ;? matches the ;, which is optional
           // 0{0,7} matches any padded zeros, which are optional and go up to 8 chars
           // @ @ search for the hex values
           $val = preg_replace('/(&#[xX]0{0,8}'.dechex(ord($search[$i])).';?)/i', $search[$i], $val);//with a ;
           // @ @ 0{0,7} matches '0' zero to seven times
           $val = preg_replace('/(&#0{0,8}'.ord($search[$i]).';?)/', $search[$i], $val); // with a ;
       }
       // now the only remaining whitespace attacks are , , and 
       $ra1 = Array('javascript', 'vbscript', 'expression', 'applet', 'meta', 'xml', 'blink', 'link', 'style', 'script', 'embed', 'object', 'iframe', 'frame', 'frameset', 'ilayer', 'layer', 'bgsound', 'title', 'base');
       $ra2 = 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');
       $ra = array_merge($ra1, $ra2);
       $found = true; // keep replacing as long as the previous round replaced something
       while ($found == true) {
           $val_before = $val;
           for ($i = 0; $i < sizeof($ra); $i++) {
               $pattern = 'https://www.jb51.net/';
               for ($j = 0; $j < strlen($ra[$i]); $j++) {
                   if ($j > 0) {
                       $pattern .= '(';
                       $pattern .= '(&#[xX]0{0,8}([9ab]);)';
                       $pattern .= '|';
                       $pattern .= '|(&#0{0,8}([9|10|13]);)';
                       $pattern .= ')*';
                   }
                   $pattern .= $ra[$i][$j];
               }
               $pattern .= '/i';
               $replacement = substr($ra[$i], 0, 2).'<x>'.substr($ra[$i], 2); // add in <> to nerf the tag
               $val = preg_replace($pattern, $replacement, $val); // filter out the hex tags
               if ($val_before == $val) {
                   // no replacements were made, so exit the loop
                   $found = false;
               }
           }
       }
       return $val;
    }
    ?>