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