private void LoginBtn_Click(object sender, RoutedEventArgs e) { LoginErrTxtBlk.Text = ""; try { string storedUsername; byte[] storedCiphertext; byte[] storedEntropy; if (!PasswordUtility.RetrievePasswordFromRegistry(out storedUsername, out storedCiphertext, out storedEntropy)) { LoginErrTxtBlk.Text = "No username and password stored in the registry. Register first."; Reset(); } else { if (PasswordUtility.Verify(usernameTxt.Text, passwordBox.Password)) { LoginErrTxtBlk.Text = "Login successful"; mainWindow = new MainWindow(); mainWindow.Show(); Close(); } else { LoginErrTxtBlk.Text = "Incorrect username and/or password. Try again."; Reset(); } } } catch (Exception ex) { MessageBox.Show(ex.Message); } }