verify_and_generate_hmac.js

/**
   * This function will check if a particular hmac(hash) coming from the url and one generted with lead is same or not
   * This is to make sure that the url can not be tampered with
   * @param {String} identity This is either the lead_id or mobileNo
   * @param {String} hash This is the generted hash in the url
   * It will return true or false based on if the hmac's match or not
   */
  checkHash(identity, clientCode, hash) {
    const generatedHash = crypto
      .createHmac('sha1', hmacSalt)
      .update(`${identity}${clientCode}`)
      .digest('hex');
    return generatedHash === hash;
  },
/**
   * This function is used to create a new hmac from identity(lead_id) and clientcode
   * @param {String} identity lead id or mobile_no to use for generating hmac
   * It will return a new hmac
   */
  createHmac(identity, clientCode) {
    const generatedHash = crypto
      .createHmac('sha1', hmacSalt)
      .update(`${identity}${clientCode}`)
      .digest('hex');
    return generatedHash;
  },