问题
I want to provide an HTML editor on my site, but don't want to open myself up to xss or other attacks that come with allowing user-generated HTML.
This is pretty similar to what Stack Overflow does. How is the HTML checked/sanitized here so that the styling information still remains, while other, more dangerous stuff (like javascript, iframes, etc.) are kept out?
Are there any libraries (preferably in PHP) that already do this?
回答1:
PHP has a function strip_tags that strips HTML and PHP tags from a string, and allows you to specify certain allowable tags. But as @webarto states, there are libraries that do this better.
From the PHP Manual.
回答2:
Your can use
strip_tags($yourData,"<a><p><div><i>") // more tags you want to keep;
If your using SQL too use
mysql_real_escape_string($data);
This is really all you need to not get injected. Do keep in mind, when using mySQL real escape you need to use strip slashes to remove them when you echo them out.
Here are the docs for strip tags and the docs for mysql escape.
回答3:
If you wish to allow some (X)HTML and restrict only tags viewed as unsafe, you can use something like KSES. Wordpress uses a solution like this.
http://sourceforge.net/projects/kses/
回答4:
In addendum to Whymarrh's post, suggestion is to have the code work take place in a subfolder of your site, and auto-alter any code that has "..", or "http://" or any mysql commands.
来源：https://stackoverflow.com/questions/9853239/how-do-i-filter-out-dangerous-html-like-so-does