<?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 Base64Url\Base64Url;
use Jose\Component\Core\JWK;
final class EdDSA implements SignatureAlgorithm
{
public function allowedKeyTypes(): array
{
return ['OKP'];
}
public function sign(JWK $key, string $input): string
{
$this->checkKey($key);
if (!$key->has('d')) {
throw new \InvalidArgumentException('The key is not private.');
}
$x = Base64Url::decode($key->get('x'));
$d = Base64Url::decode($key->get('d'));
$secret = $d.$x;
switch ($key->get('crv')) {
case 'Ed25519':
return \sodium_crypto_sign_detached($input, $secret);
default:
throw new \InvalidArgumentException('Unsupported curve');
}
}
public function verify(JWK $key, string $input, string $signature): bool
{
$this->checkKey($key);
$public = Base64Url::decode($key->get('x'));
switch ($key->get('crv')) {
case 'Ed25519':
return \sodium_crypto_sign_verify_detached($signature, $input, $public);
default:
throw new \InvalidArgumentException('Unsupported curve');
}
}
private function checkKey(JWK $key)
{
if (!\in_array($key->get('kty'), $this->allowedKeyTypes(), true)) {
throw new \InvalidArgumentException('Wrong key type.');
}
foreach (['x', 'crv'] as $k) {
if (!$key->has($k)) {
throw new \InvalidArgumentException(\sprintf('The key parameter "%s" is missing.', $k));
}
}
if (!\in_array($key->get('crv'), ['Ed25519'], true)) {
throw new \InvalidArgumentException('Unsupported curve.');
}
}
public function name(): string
{
return 'EdDSA';
}
}