javascript - How to store HTML code in the database

Question

Now there are 3 questions:

• If I have the following HTML code that needs to be stored in a certain field in the database table, should I save it directly? Or do I need to encode it and then save it? Ask God for advice! If you want to encode, which method should be used? Please give me the specific code, thank you

<!-- JiaThis Button BEGIN -->
<script type="text/javascript" src="http://v3.jiathis.com/code/jiathis_r.js?move=0" charset="utf-8"></script>
<!-- JiaThis Button END -->

• If I have a string in JSON format that I want to save to a field in a database table, do I need to encode it before saving it? Or deposit directly?

• Is there anything else that should be paid attention to when storing data in the database? Please give me some advice, thank you

Answer 1

1. html 代码一般使用 stripcslashes 对其片段转义入库，取出用addcslashes 还原，找一些开源的过滤 xss class library, such as

2. If it is a string in JSON format, just save it directly

3. Avoid SQL注入请使用PDO preprocessing http://php.net/manual/zh/book...

A simple post to prevent XSS

<?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 <javarrreeescript>  
   // note that you have to handle splits with \n, \r, and \t 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=@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 \t, \n, and \r 
   $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++) { 
         $pattern = '/'; 
         for ($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;  
} 

Answer 2

First, introducing js into the code and directly storing it in the database without processing it is a very irrational behavior. Please solve it in the following way
1: Convert the information, htmlspecialchars, and html into entities, and then save them in the database. This method is lazy and easy to bypass
2: Use regular expressions to get the content of src and save it in the database