public override bool ChangePassword(string userKey, string oldPassword, string newPassword)
 {
     if (ValidateUser(userKey, oldPassword)) {
         UserData userData = new UserData {
             PasswordHash = UserData.GetHashPassword(newPassword),
             Email = userKey
         };
         using (UserServiceClient client = new UserServiceClient()) {
             client.UserUpdate(userData.Email, userData);
         }
         return true;
     } else {
         return false;
     }
 }