- $header = base64_encode($header);
- $payload = base64_encode($payload);
- $signature = hash_hmac('sha512', $header . '.' . $payload, $secret);
+ $header = Base64Url::encode($header);
+ $payload = Base64Url::encode($payload);
+ $signature = Base64Url::encode(hash_hmac('sha512', $header . '.' . $payload, $secret, true));