IPN validation examples

Webhook example: Payments

{
"payment_id":123456789,
"parent_payment_id":987654321,
"invoice_id":null,
"payment_status":"finished",
"pay_address":"address",
"payin_extra_id":null,
"price_amount":1,
"price_currency":"usd",
"pay_amount":15,
"actually_paid":15,
"actually_paid_at_fiat":0,
"pay_currency":"trx",
"order_id":null,
"order_description":null,
"purchase_id":"123456789",
"outcome_amount":14.8106,
"outcome_currency":"trx",
"payment_extra_ids":null,
"fee": {
"currency":"btc",
"depositFee":0.09853637216235617,
"withdrawalFee":0,
"serviceFee":0
}
}

function sortObject(obj) {
  return Object.keys(obj).sort().reduce(
    (result, key) => {
      result[key] = (obj[key] && typeof obj[key] === 'object') ? sortObject(obj[key]) : obj[key]
      return result
    },
    {}
  )
}
const hmac = crypto.createHmac('sha512', notificationsKey);
hmac.update(JSON.stringify(sortObject(params)));
const signature = hmac.digest('hex');

function tksort(&$array)
  {
  ksort($array);
  foreach(array_keys($array) as $k)
    {
    if(gettype($array[$k])=="array")
      {
      tksort($array[$k]);
      }
    }
  }
function check_ipn_request_is_valid()
    {
        $error_msg = "Unknown error";
        $auth_ok = false;
        $request_data = null;
        if (isset($_SERVER['HTTP_X_NOWPAYMENTS_SIG']) && !empty($_SERVER['HTTP_X_NOWPAYMENTS_SIG'])) {
            $recived_hmac = $_SERVER['HTTP_X_NOWPAYMENTS_SIG'];
            $request_json = file_get_contents('php://input');
            $request_data = json_decode($request_json, true);
            tksort($request_data);
            $sorted_request_json = json_encode($request_data, JSON_UNESCAPED_SLASHES);
            if ($request_json !== false && !empty($request_json)) {
                $hmac = hash_hmac("sha512", $sorted_request_json, trim($this->ipn_secret));
                if ($hmac == $recived_hmac) {
                    $auth_ok = true;
                } else {
                    $error_msg = 'HMAC signature does not match';
                }
            } else {
                $error_msg = 'Error reading POST data';
            }
        } else {
            $error_msg = 'No HMAC signature sent.';
        }
    }

import json 
import hmac 
import hashlib

def np_signature_check(np_secret_key, np_x_signature, message):
    sorted_msg = json.dumps(message, separators=(',', ':'), sort_keys=True)
    digest = hmac.new(
    str(np_secret_key).encode(), 
    f'{sorted_msg}'.encode(),
    hashlib.sha512)
    signature = digest.hexdigest()
    if signature == np_x_signature:
        return
    else:
        print("HMAC signature does not match")