Create an invoice

function verifyCallbackData () {
  if (!isset($_POST['verify_hash'])) {
    return false;
  }
  $post = $_POST;
  $verifyHash = $post['verify_hash'];
  unset($post['verify_hash']);
  ksort($post);
  if (isset($post['expire_utc'])){
    $post['expire_utc'] = (string)$post['expire_utc'];
  }
  if (isset($post['tx_urls'])){
    $post['tx_urls'] = html_entity_decode($post['tx_urls']);
  }
  $postString = serialize($post);
  $checkKey = hash_hmac('sha1', $postString, 'SECRET_KEY');
  if ($checkKey != $verifyHash) {
    return false;
  }
  return true;
}

composer require plisio/plisio-api-php

function verifyCallbackData ()
  $plisio = new \Plisio\ClientAPI($secretKey);
  return $plisio->verifyCallbackData($_POST, $secretKey);
}

const http = require("http");
const crypto = require('crypto');
const secretKey = 'SECRET_KEY';

const host = '127.0.0.1';
const port = 8000;

const vallidateRequest = function (data) {
  if (typeof data === 'object' && data.verify_hash && secretKey) {    
    const ordered = {...data};
    delete ordered.verify_hash;    
    const string = JSON.stringify(ordered);
    const hmac = crypto.createHmac('sha1', secretKey);
    hmac.update(string);
    const hash = hmac.digest('hex');
    return hash === data.verify_hash;
  }
  return false;
}

const requestListener = function (req, res) {
  let chunks = '';
  req.on('data', chunk => chunks += chunk);
  req.on('end', () => {
    let data;
    try {
      data = JSON.parse(chunks);
      res.setHeader("Content-Type", "application/json");
    } catch (e){
      // console.error(e);
      data = false;
    }

    if (data && vallidateRequest(data)) {
      res.writeHead(200);
      res.end('This is a correct JSON callback');
    } else {
      res.writeHead(422);
      res.end('Incorrect data 1');
    }
  })
};

const server = http.createServer(requestListener);
server.listen(port, host, () => {
  console.log(`Server is running on http://${host}:${port}`);
});