<?php
declare(strict_types=1);
/*
* This file is part of the WebPush library.
*
* (c) Louis Lagrange <lagrange.louis@gmail.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Minishlink\WebPush;
use Base64Url\Base64Url;
use Brick\Math\BigInteger;
use Jose\Component\Core\JWK;
use Jose\Component\Core\Util\Ecc\PublicKey;
class Utils
{
/**
* @param string $value
*
* @return int
*/
public static function safeStrlen(string $value): int
{
return mb_strlen($value, '8bit');
}
/**
* @param PublicKey $publicKey
*
* @return string
*/
public static function serializePublicKey(PublicKey $publicKey): string
{
$hexString = '04';
$point = $publicKey->getPoint();
if ($point->getX() instanceof BigInteger) {
$hexString .= str_pad($point->getX()->toBase(16), 64, '0', STR_PAD_LEFT);
$hexString .= str_pad($point->getY()->toBase(16), 64, '0', STR_PAD_LEFT);
} else { // @phpstan-ignore-line
$hexString .= str_pad(gmp_strval($point->getX(), 16), 64, '0', STR_PAD_LEFT);
$hexString .= str_pad(gmp_strval($point->getY(), 16), 64, '0', STR_PAD_LEFT); // @phpstan-ignore-line
}
return $hexString;
}
/**
* @param JWK $jwk
*
* @return string
*/
public static function serializePublicKeyFromJWK(JWK $jwk): string
{
$hexString = '04';
$hexString .= str_pad(bin2hex(Base64Url::decode($jwk->get('x'))), 64, '0', STR_PAD_LEFT);
$hexString .= str_pad(bin2hex(Base64Url::decode($jwk->get('y'))), 64, '0', STR_PAD_LEFT);
return $hexString;
}
/**
* @param string $data
*
* @return array
*/
public static function unserializePublicKey(string $data): array
{
$data = bin2hex($data);
if (mb_substr($data, 0, 2, '8bit') !== '04') {
throw new \InvalidArgumentException('Invalid data: only uncompressed keys are supported.');
}
$data = mb_substr($data, 2, null, '8bit');
$dataLength = self::safeStrlen($data);
return [
hex2bin(mb_substr($data, 0, $dataLength / 2, '8bit')),
hex2bin(mb_substr($data, $dataLength / 2, null, '8bit')),
];
}
}