// Course Number: COSC 645 Applied Cryptography // Program Name: GetSharesClient.java // Authors: Brian Hoffman // Derek Waby // Kypros Ioannou // Harsha V. Reddy // Description: This class implements a network client whose task is to // contact a ShamirServer and obtain a secret share. The program // provides a simple GUI where the user can enter the address // and port number of the server and hit a request share // button to transmit a request for a single share to the // server. When received back from the server, the share is // conveniently displayed in a set of text fields. The share // can then be saved using a save button at the bottom of the // GUI. Finally, the GUI can be cleared by hitting the clear // button. // Java Core Packages import java.awt.*; import java.awt.event.*; import java.io.*; import java.net.*; import java.util.ArrayList; import java.math.BigInteger; // Jave Extension Packages import javax.swing.*; import javax.swing.border.*; public class GetSharesClient extends JFrame { // private class variables public final static int DEFAULT_PORT = 4567; private File saveDir = new File("."); // gui components private Container container; private GriddedPanel requestPanel; private GriddedPanel inputPanel; private JLabel serverAddLabel; private JTextField serverAddField; private JLabel serverPortLabel; private JTextField serverPortField; private JLabel shareXLabel; private JTextField shareXField; private JLabel shareYLabel; private JTextArea shareYArea; private JLabel primeLabel; private JTextArea primeArea; private JPanel buttonPanel; private JButton requestButton; private JButton clearButton; private JButton saveButton; // ------------------------------------------------------------------------ // constructor - sets up the GUI //------------------------------------------------------------------------- public GetSharesClient() { // title the window super("Request Shamir Secret Shares"); // get content pane and set layout container = getContentPane(); container.setLayout(new BorderLayout()); // create components for the request panel serverAddLabel = new JLabel("Enter Server's Address"); serverAddField = new JTextField(20); serverPortLabel = new JLabel("Enter Port Number"); serverPortField = new JTextField(5); serverPortField.setText(Integer.toString(DEFAULT_PORT)); shareXLabel = new JLabel("X:"); shareXField = new JTextField(20); shareYLabel = new JLabel("Y:"); shareYArea = new JTextArea(5,20); primeLabel = new JLabel("Prime:"); primeArea = new JTextArea(5,20); requestButton = new JButton("Request Share"); requestButton.addActionListener(new RequestButtonHandler()); clearButton = new JButton("Clear"); clearButton.addActionListener(new ClearButtonHandler()); saveButton = new JButton ("Save"); saveButton.addActionListener(new SaveButtonHandler(this)); // add components to the requestPanel requestPanel = new GriddedPanel(); requestPanel.setBorder(BorderFactory.createTitledBorder( BorderFactory.createEtchedBorder(), "The Share", TitledBorder.CENTER, TitledBorder.TOP )); requestPanel.addComponent(shareXLabel, 1, 1); requestPanel.addFilledComponent(shareXField, 1, 2, 2, 1, GridBagConstraints.HORIZONTAL); requestPanel.addComponent(shareYLabel, 2, 1); requestPanel.addFilledComponent(new JScrollPane(shareYArea), 2, 2, 2, 2, GridBagConstraints.BOTH); requestPanel.addComponent(primeLabel, 4, 1); requestPanel.addFilledComponent(new JScrollPane(primeArea), 4, 2, 2, 2, GridBagConstraints.BOTH); // add components to the inputPanel inputPanel = new GriddedPanel(); inputPanel.addComponent(serverAddLabel, 1, 1, 3, 1); inputPanel.addFilledComponent(serverAddField, 2, 2, 2, 1, GridBagConstraints.HORIZONTAL); inputPanel.addComponent(serverPortLabel, 3, 1, 3, 1); inputPanel.addFilledComponent(serverPortField, 4, 2, 2, 1, GridBagConstraints.HORIZONTAL); inputPanel.addFilledComponent(requestPanel, 5, 2, 2, 1, GridBagConstraints.BOTH); container.add(inputPanel, BorderLayout.CENTER); // build the button panel and add it buttonPanel = new JPanel(new GridLayout(1,3)); buttonPanel.add(requestButton); buttonPanel.add(clearButton); buttonPanel.add(saveButton); container.add(buttonPanel, BorderLayout.SOUTH); // display the initial GUI pack(); setVisible(true); } // ------------------------------------------------------------------------ // RequestButtonHandler //------------------------------------------------------------------------- private class RequestButtonHandler implements ActionListener { public void actionPerformed(ActionEvent event) { ClientConnection connection = new ClientConnection(serverAddField.getText(), Integer.parseInt(serverPortField.getText())); ShamirMsg shareRequest; ShamirMsg shareReturned; // check if the connection was successful if (!connection.connect()) { JOptionPane.showMessageDialog(null, "Error connecting to server!", "Connection Error", JOptionPane.ERROR_MESSAGE); return; } // send a request for share message try { // send request shareRequest = new ShamirMsg("requestShare"); connection.sendObject(shareRequest); // read reply shareReturned = (ShamirMsg) connection.readObject(); // display reply shareXField.setText(shareReturned.getX().toString()); shareYArea.setText(shareReturned.getY().toString()); primeArea.setText(shareReturned.getPrime().toString()); // send termination message connection.sendObject(new ShamirMsg("terminate")); } catch(Exception e) { JOptionPane.showMessageDialog(null, "Error requesting share!", "Share Request Error", JOptionPane.ERROR_MESSAGE); e.printStackTrace(); } finally { connection.close(); } } } // ------------------------------------------------------------------------ // ClearButtonHandler //------------------------------------------------------------------------- private class ClearButtonHandler implements ActionListener { public void actionPerformed(ActionEvent event) { serverAddField.setText(""); serverPortField.setText(Integer.toString(DEFAULT_PORT)); shareXField.setText(""); shareYArea.setText(""); primeArea.setText(""); } } // ------------------------------------------------------------------------ // SaveButtonHandler //------------------------------------------------------------------------- private class SaveButtonHandler implements ActionListener { private JFrame parent; public SaveButtonHandler(JFrame inFrame) { parent = inFrame; } public void actionPerformed(ActionEvent event) { // open a file chooser dialog and get the input file JFileChooser chooser = new JFileChooser(); chooser.setFileSelectionMode(JFileChooser.FILES_ONLY); chooser.setCurrentDirectory(saveDir); if(chooser.showSaveDialog(parent) != JFileChooser.APPROVE_OPTION) return; File fileName = chooser.getSelectedFile(); saveDir = new File(fileName.getParent()); // check that the file name is valid if (fileName == null || fileName.getName().equals("")) { JOptionPane.showMessageDialog(parent, "Invalid File Name", "Invalid File Name", JOptionPane.ERROR_MESSAGE); return; } // setup file variables FileWriter theFile; PrintWriter outFile = null; try { theFile = new FileWriter(fileName); outFile = new PrintWriter(theFile); outFile.println(shareXField.getText()); outFile.println(shareYArea.getText()); outFile.println(primeArea.getText()); } // deal with any io problems catch (IOException ioException) { JOptionPane.showMessageDialog(null, "Error writing to file!", "File Read Error", JOptionPane.ERROR_MESSAGE); ioException.printStackTrace(); } // close the file stream finally { if (outFile != null) outFile.close(); } // end finally } // end ActionPerformed } // end SaveButtonHandler // ------------------------------------------------------------------------ // main - executes application //------------------------------------------------------------------------- public static void main (String args[]) { GetSharesClient application = new GetSharesClient(); application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } }