Sample NodeJs application to send HMAC authentication

index.js

const https = require('https');
const fs = require('fs');
const crypto = require('crypto');

const data = JSON.stringify({
    foo: 'bar'
  }),
  path = '/ok',
  method = 'POST';

// process.env["NODE_TLS_REJECT_UNAUTHORIZED"] = 0;

const url = 'localhost',
  username = 'hmac-user',
  secret = '~,6a=HFaC/P]R5Zp',
  uuid = '9b83f786-5a70-11eb-ae93-0242ac130002',
  algorithm = 'hmac-sha256';

let authorization, digestBodyHeader, dateFormat, signingString, signature;

dateFormat = new Date().toUTCString();
digestBodyHeader = 'SHA-256=' + crypto.createHash('sha256').update(data).digest('base64');
signingString = 'x-date: ' + dateFormat + '\n' + method + ' ' + path + ' HTTP/1.1' + '\n' + 'x-uuid: ' + uuid + '\n' + 'digest: ' + digestBodyHeader;
signature = crypto.createHmac('sha256', secret).update(signingString).digest('base64');
authorization = 'hmac username="' + username + '", algorithm="' + algorithm + '", headers="x-date request-line x-uuid digest", signature="' + signature + '"';

console.log('variables:\n',
  'url:', url, '\n',
  'username:', username, '\n',
  'secret:', secret, '\n',
  'body:', data, '\n',
  'signingString:', signingString, '\n',
  'signature:', signature, '\n',
  'authorization:', authorization);

const options = {
  hostname: url,
  port: 443,
  path: path,
  method: method,
  ca: [fs.readFileSync('/usr/local/share/ca-certificates/CACert.crt')],
  headers: {
    'Digest': digestBodyHeader,
    'Authorization': authorization,
    'X-Date': dateFormat,
    'X-UUID': uuid,
    'Content-Type': 'application/json',
    'Content-Length': data.length
  }
};

const req = https.request(options, res => {
  console.log(`response header: ${JSON.stringify(res.headers, null, " ")}`);

  res.on('data', d => {
    process.stdout.write(d)
  })
});

req.on('error', error => {
  console.error(error)
});

req.write(data);
console.log('request:', req._header);
req.end();