Re: secure alternative to HTTP_REFERER
| From: | Chris Shiflett | Date: | Tue, 24 Apr 2007 15:07:55 +0000 |
| Subject: | Re: secure alternative to HTTP_REFERER | ||
| References: | 1 2 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-253596@lists.php.net to get a copy of this message | ||
Stut wrote:
> You could put a hash value into a hidden field on the form, and
> also store it in the session. When the form is submitted only
> accept it if the hashes match.
>
> However, this is very easy to get around, so I suggest you
> consider why you think you need this level of checking. Assuming
> you're properly validating and escaping all input coming from
> outside the app, IMHO this type of "security" should not be needed.
It can useful when you want to verify intent, which is an important
consideration these days:
http://shiflett.org/articles/cross-site-request-forgeries
(I have an update that I need to publish, but this should be enough to
explain the potential problems this technique can help prevent.)
Chris
--
Chris Shiflett
http://shiflett.org/