Files

62 lines
1.5 KiB
PHP

<?php
declare(strict_types=1);
/*
* The MIT License (MIT)
*
* Copyright (c) 2014-2020 Spomky-Labs
*
* This software may be modified and distributed under the terms
* of the MIT license. See the LICENSE file for details.
*/
namespace Jose\Component\Signature\Algorithm;
use Base64Url\Base64Url;
use function in_array;
use InvalidArgumentException;
use function is_string;
use Jose\Component\Core\JWK;
abstract class HMAC implements MacAlgorithm
{
public function allowedKeyTypes(): array
{
return ['oct'];
}
public function verify(JWK $key, string $input, string $signature): bool
{
return hash_equals($this->hash($key, $input), $signature);
}
public function hash(JWK $key, string $input): string
{
$k = $this->getKey($key);
return hash_hmac($this->getHashAlgorithm(), $input, $k, true);
}
/**
* @throws InvalidArgumentException if the key is invalid
*/
protected function getKey(JWK $key): string
{
if (!in_array($key->get('kty'), $this->allowedKeyTypes(), true)) {
throw new InvalidArgumentException('Wrong key type.');
}
if (!$key->has('k')) {
throw new InvalidArgumentException('The key parameter "k" is missing.');
}
$k = $key->get('k');
if (!is_string($k)) {
throw new InvalidArgumentException('The key parameter "k" is invalid.');
}
return Base64Url::decode($k);
}
abstract protected function getHashAlgorithm(): string;
}