oficial/app/src/Service/HMAC.php

<?php
namespace Incoviba\Service;

use Incoviba\Common\Ideal;

class HMAC extends Ideal\Service
{
    public function validate(string $timestamp, string $requestSignature, string $requestId, string $secret): bool
    {
        $message = "{$timestamp}.{$requestId}";
        $encodedSecret = mb_convert_encoding($secret, 'UTF-8');
        $encodedMessage = mb_convert_encoding($message, 'UTF-8');
        $hmacObject = hash_hmac('sha256', $encodedMessage, $encodedSecret);
        return hash_equals($hmacObject, $requestSignature);
    }
}