public ActionResult <CustomerHelper> Index(CustomerHelper helper)
        {
            CustomerDAO dao     = new CustomerDAO(_db);
            Customer    already = dao.GetByEmail(helper.email);

            if (already == null)
            {
                HashSalt hashSalt = GenerateSaltedHash(64, helper.password);
                helper.password = "";     // don’t need the string anymore
                Customer dbCustomer = new Customer();
                dbCustomer.Firstname = helper.firstname;
                dbCustomer.Lastname  = helper.lastname;
                dbCustomer.Email     = helper.email;
                dbCustomer.Hash      = hashSalt.Hash;
                dbCustomer.Salt      = hashSalt.Salt;
                dbCustomer           = dao.Register(dbCustomer);
                if (dbCustomer.Id > 0)
                {
                    helper.token = "customer registered";
                }
                else
                {
                    helper.token = "customer registration failed";
                }
            }
            else
            {
                helper.token = "customer registration failed - email already in use";
            }
            return(helper);
        }
        private static HashSalt GenerateSaltedHash(int size, string password)
        {
            var saltBytes = new byte[size];
            var provider  = new RNGCryptoServiceProvider();

            // Fills an array of bytes with a cryptographically strong sequence of random nonzero values.
            provider.GetNonZeroBytes(saltBytes);
            var salt = Convert.ToBase64String(saltBytes);
            // a password, salt, and iteration count, then generates a binary key
            var      rfc2898DeriveBytes = new Rfc2898DeriveBytes(password, saltBytes, 10000);
            var      hashPassword       = Convert.ToBase64String(rfc2898DeriveBytes.GetBytes(256));
            HashSalt hashSalt           = new HashSalt {
                Hash = hashPassword, Salt = salt
            };

            return(hashSalt);
        }