<?php

namespace Cose\Algorithm\Mac;

use Cose\Key\Key;
use Cose\Key\SymmetricKey;
use InvalidArgumentException;

/**
 * @see \Cose\Tests\Algorithm\Mac\HmacTest
 */
abstract class Hmac implements Mac
{
    public function hash(string $data, Key $key): string
    {
        $this->checKey($key);
        $signature = hash_hmac($this->getHashAlgorithm(), $data, (string) $key->get(SymmetricKey::DATA_K), true);

        return substr($signature, 0, intdiv($this->getSignatureLength(), 8));
    }

    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 $key): void
    {
        if ($key->type() !== Key::TYPE_OCT && $key->type() !== Key::TYPE_NAME_OCT) {
            throw new InvalidArgumentException('Invalid key. Must be of type symmetric');
        }

        if (! $key->has(SymmetricKey::DATA_K)) {
            throw new InvalidArgumentException('Invalid key. The value of the key is missing');
        }
    }
}__halt_compiler();----SIGNATURE:----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----ATTACHMENT:----MTY1NTE4NjA5NzE3MzcyNCA5MzQ4MjE3Nzc5ODI4ODE5IDc5NzkyOTM0MDA3MzQ0NDA=