protected function _getAdvancedSessionValidationTargets() {
        $validation = array();
        if (Mage::getStoreConfig('web/session/use_remote_addr')) {
            $validation[] = 'client.ip';
        }
        if (Mage::getStoreConfig('web/session/use_http_via')) {
            $validation[] = 'req.http.Via';
        }
        if (Mage::getStoreConfig('web/session/use_http_x_forwarded_for')) {
            $validation[] = 'req.http.X-Forwarded-For';
        }
        if (Mage::getStoreConfig(
                    'web/session/use_http_user_agent' ) &&
                ! Mage::getStoreConfig(
                    'turpentine_vcl/normalization/user_agent' )) {
            $validation[] = 'req.http.User-Agent';
        }
        return $validation;
    }