<?php
declare(strict_types=1);
/*
* The MIT License (MIT)
*
* Copyright (c) 2014-2018 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 Jose\Component\Core\JWK;
use Jose\Component\Core\Util\ECKey;
use Jose\Component\Core\Util\ECSignature;
abstract class ECDSA implements SignatureAlgorithm
{
public function __construct()
{
if (!\defined('OPENSSL_KEYTYPE_EC')) {
throw new \RuntimeException('Elliptic Curve key type not supported by your environment.');
}
}
public function allowedKeyTypes(): array
{
return ['EC'];
}
public function sign(JWK $key, string $input): string
{
$this->checkKey($key);
if (!$key->has('d')) {
throw new \InvalidArgumentException('The EC key is not private');
}
$pem = ECKey::convertPrivateKeyToPEM($key);
$result = \openssl_sign($input, $signature, $pem, $this->getHashAlgorithm());
if (false === $result) {
throw new \RuntimeException('Signature failed.');
}
return ECSignature::fromDER($signature, $this->getSignaturePartLength());
}
public function verify(JWK $key, string $input, string $signature): bool
{
$this->checkKey($key);
try {
$der = ECSignature::toDER($signature, $this->getSignaturePartLength());
$pem = ECKey::convertPublicKeyToPEM($key);
return 1 === \openssl_verify($input, $der, $pem, $this->getHashAlgorithm());
} catch (\Exception $e) {
return false;
}
}
abstract protected function getHashAlgorithm(): string;
abstract protected function getSignaturePartLength(): int;
private function checkKey(JWK $key)
{
if (!\in_array($key->get('kty'), $this->allowedKeyTypes(), true)) {
throw new \InvalidArgumentException('Wrong key type.');
}
foreach (['x', 'y', 'crv'] as $k) {
if (!$key->has($k)) {
throw new \InvalidArgumentException(\sprintf('The key parameter "%s" is missing.', $k));
}
}
}
}