File Content: Hmac.php <?php declare(strict_types=1); /* * The MIT License (MIT) * * Copyright (c) 2014-2021 Spomky-Labs * * This software may be modified and distributed under the terms * of the MIT license. See the LICENSE file for details. */ namespace Cose\Algorithm\Mac; use Assert\Assertion; use Cose\Key\Key; abstract class Hmac implements Mac { public function hash(string $data, Key $key): string { $this->checKey($key); $signature = hash_hmac($this->getHashAlgorithm(), $data, $key->get(-1), true); return mb_substr($signature, 0, intdiv($this->getSignatureLength(), 8), '8bit'); } public function verify(string $data, Key $key, string $signature): bool { return hash_equals($this->hash($data, $key), $signature); } abstract protected function getHashAlgorithm(): string; abstract protected function getSignatureLength(): int; private function checKey(Key $key): void { Assertion::eq($key->type(), 4, 'Invalid key. Must be of type symmetric'); Assertion::true($key->has(-1), 'Invalid key. The value of the key is missing'); } } Submit