Codeigniter - Disable XSS filtering on a post basis

Von Schmytt picture Von Schmytt · Sep 24, 2010 · Viewed 16.7k times · Source

I'm trying to set up a CMS on the back of a site but whenever post data has a <a href=... in it the post data gets scrapped.

I've got $config['global_xss_filtering'] = TRUE; in config

My question is there a way of disabling xss filtering for one item?

e.g.

$this->input->post('content', true); - turns it on, but how to turn it off?

Thanks everyone.

PVS

Answer

treeface picture treeface · Sep 24, 2010

If you want to change the default behavior of the post() method, you can extend the core Input library, or if you're lazy you can just change line 278 (or so) of the Input library to read:

/**
* Fetch an item from the POST array
*
* @access   public
* @param    string
* @param    bool
* @return   string
*/
function post($index = '', $xss_clean = TRUE)
{
    return $this->_fetch_from_array($_POST, $index, $xss_clean);
}

The only difference here is that I've changed the $xss_clean variable to TRUE instead of FALSE. Now you can turn off global XSS filtering and it will automatically filter inputs unless you specify false as the second parameter in your call to the Input library's post() method. Just one method down is the get() method, and you can change that in the same way.

However, if I were you, I'd just extend the native library, because there's a good chance you'll have forgotten about this by the time you update CodeIgniter, and then you'll suddenly be wondering why you're getting XSS attacked. That would look like this:

class MY_Input extends CI_Input {

    function My_Input()
    {
        parent::CI_Input();
    }

    function post($index = '', $xss_clean = TRUE)
    {
        return parent::post($index, $xss_clean);
    }
}

You can learn more about extending libraries here:

http://codeigniter.com/user_guide/general/creating_libraries.html