protected function supportedInfo($name, $throw = false) {
        switch ($name) {
            case 'aes128':
            case 'aes256':
                $cipher = 'aes-'.substr($name, 3).'-cbc';
                return ['encrypt', 'decrypt', $cipher, false];
            case 'hsha1':
            case 'hsha256':
                $hash = substr($name, 1);
                return ['hmac', 'verifyHmac', $hash, true];
        }
        return $this->exception($throw, "Spec $name not supported.", 400);
    }