php.net hash_hmac:
(PHP 5 >= 5.1.2, PECL hash >= 1.1)
Не?!
Добавлено 4 минуты спустя:
/сайт/Install.txt
REQUIREMENTS
------------
To install Cotonti you need the following server software pre-installed:
* WWW Server (Apache, nginx, etc)
* PHP 5.2 or higher
* MySQL 5.0 or higher
