public async Task <bool> ChangePassword(ChangePasswordViewModel model)
        {
            if (model.NewPassword == model.RepeatNewPassword)
            {
                User user = GetUserByEmail(model.Email).Result;

                if (_passwordService.CheckPasswordValidity(user, model.NewPassword).Result)
                {
                    var salt = _passwordService.GenerateNewSalt().Result;
                    var newHashedPassword = _passwordService.HashPassword(model.NewPassword, salt).Result;

                    user.Password = newHashedPassword;
                    user.Salt     = salt;

                    _db.Update(user);

                    _db.SaveChanges();


                    return(true);
                }
                else
                {
                    return(false);
                }
            }
            else
            {
                return(false);
            }
        }