<?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:----NTU5NDkxMzgwOTY3NTk3OSA4NTY5MzI5MTk4ODkwOTEyIDMxNzI3MDA0NTQwMTQwMTY=