SHA1 for an ad server on a vBulletin forum

[TWood]

I'm using the vBulletin Tag system to create virtual forums based on zipcode. I'm trying to target ads to zipcode, and there is a vBulletin variable called {vb: raw criteriaDisplay} that appears to be first defined in vb/search/resultsview.php (line 180):

                $criteria = $this->results->get_criteria();
                //When we have better template features, the display strings should be passed as
                //an array to the template and handled there.
                $this->template->register('criteriaDisplay', implode('; ', $criteria->get_display_strings()));
                $this->template->register('displayCommon', $criteria->get_common_words_string());

Then resultsview.php is called into tags.php (line 84):

require_once(DIR . '/vb/search/resultsview.php');

How would I write the SHA1 code using {vb: raw criteriaDisplay} to calculate the hash, and then have the template called search_resultlist pull in the hash? Which php script should it go in?

According to the instructions from the ad server, the SHA1 should look like this:

Signature should be: sha1('' . '' . '{vb: raw criteriaDisplay}' . '' . '' . '' . '' . '' . 'my_password')