[jj]

With the fact you are using a custom built page, there should be no problems on dropping your site user table and base the page onto the vbulletin user table.

I wrote a custom "cms" for our page as well, and I'm hooking into the vbulletin user table for authentication on site (the login is handled by vbulletin completely).

Here's a snippet of my custom security/user class

PHP Code:

    function auth_phpbb($data, $passwd) {
        return false;
    }
    function auth_vbulletin($data, $passwd) {
        /*
         * Passwortchecks
         */
        if ($data['salt'] != "") {
            $passwdMD5 = md5( md5( $passwd ) . $data['salt'] );
        } else {
            $passwdMD5 = md5( $passwd );
        }

        if ($passwdMD5 == $data['password']) {
            $_SESSION['oSession']['userinfo'] = array (
                'userid' => $data['userid'],
                'username' => $data['username']
            );
            session_regenerate_id();
            return true;
        } else {
            unset( $_SESSION['oSession']['userinfo'] );
            return false;
        }
    }
    function authenticate($system = 'DEFAULT') {
        if ( $system=='DEFAULT' ) {
            $system='auth_'.$this->config["main"]["authsystem"];
        } else {
            $system='auth_'.$system;
        }
        if (!method_exists($this,$system)) {
            return false;
        }
        if (
            isset($_POST['login']) &&
            is_array($_POST['login']) &&
            !empty($_POST['login']['username']) &&
            !empty($_POST['login']['password'])
        ) {
            $data = $this->getUser(htmlentities(strip_tags($_POST['login']['username']),ENT_QUOTES));
            if (
                $data &&
                (
                    $this->isMemberOfGroup($data['userid'],4) ||     // Mitglieder
                    $this->isMemberOfGroup($data['userid'],6) ||     // Trials
                    $this->isMemberOfGroup($data['userid'],1) ||     // Administratoren
                    $this->isSuperAdmin($data['userid'])            // SuperAdmins
                )
            ) {
                return call_user_method($system, $this, $data, $_POST['login']['password']);
            }
        }
        return false;
    } 


Maybe it's helpfull.

Cheers
Jens