CVEList.java

package kamil.cve;

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.io.IOException;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;

import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

public class CVEList {
	static Logger log = LogManager.getLogger();

	// timeout for webpage download in miliseconds

	static final int TIMEOUT = 10000;

	// URL definitions
	private static final String url_search_prefix = "https://web.nvd.nist.gov/view/vuln/search-results?query=";
	private static final String url_search_sufix = "&search_type=last3months&cves=on";

	// CSS selectors
	private static final String css_CVE_link = "div#searchResultsSection.searchResults dl dt a[href^=detail?vulnId=CVE-]";
	private static final String css_Page_Navigator = "div.pageNavigator:nth-child(3)";

	// Storage objects
	private List<CVEListEntry> entries = new ArrayList<CVEListEntry>();
	private LinkedHashMap<String,String> pageNavigatorButtons = new LinkedHashMap<String,String>();

	// UI elements
	private JFrame jf;
	private JTextField searchField;
	private JPanel pageNavigator;
	private JList<DefaultListModel<String>> list;
	private DefaultListModel<CVEListEntry> model;
	private JScrollPane scrollPane;

	// Action Listeners
	private CVESearchButtonAL searchButtonAL = new CVESearchButtonAL(this);
	private CVEListMouseAdapter mouseAdapter = new CVEListMouseAdapter();


	/**
	 * Constructor of CVEList, which triggers GUI rendering after object is created.
	 */
	public CVEList(){
		log.info("CVEList created!");
		// Spawn GUI
		createAndDisplayGUI();
	}

	/**
	 * Function creating and displaying initial GUI. It is run inside AWT Event Dispatcher thread.
	 */
	private void createAndDisplayGUI(){
		// execute GUI creation in AWT Event Dispatcher thread
		javax.swing.SwingUtilities.invokeLater(new Runnable() {
			@Override
			public void run() { 
				log.info("Starting to draw GUI");
				// create main frame
				jf = new JFrame("CVE Explorer");

				// search panel
				JPanel searchPanel = new JPanel();
				searchPanel.setLayout(new FlowLayout());

				// search button
				JButton searchButton = new JButton("Search");
				searchButton.addActionListener(searchButtonAL);

				// search field
				searchField = new JTextField(30);
				searchField.setText("Type in a product or vendor name");
				searchField.setToolTipText("Type in search query and press search.");

				// add search button and search field to search panel
				searchPanel.add(searchField);
				searchPanel.add(searchButton);

				// create empty list 
				model = new DefaultListModel<CVEListEntry>();
				list = new JList(model);
				list.addMouseListener(mouseAdapter);
				list.setCellRenderer(new CVEListEntryRenderer());

				// put search list in scroll pane
				scrollPane = new JScrollPane();
				scrollPane.setViewportView(list);
				scrollPane.setVisible(false);

				// Page navigation panel
				pageNavigator = new JPanel();
				pageNavigator.setLayout(new FlowLayout());


				// Add everything to main frame
				jf.setLayout(new BorderLayout());
				jf.getContentPane().add(searchPanel, BorderLayout.NORTH);
				jf.getContentPane().add(scrollPane, BorderLayout.CENTER);
				jf.getContentPane().add(pageNavigator, BorderLayout.SOUTH);

				// Pack and display main frame
				jf.pack();
				jf.setVisible(true);
				
				// Set default close action
				jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
				
				// Bind default (enter key) button to Search button
				jf.getRootPane().setDefaultButton(searchButton);
				log.info("GUI created!");
			}
		}); 
	}

	/** 
	 * This method executes a search query for given URL. It will try to download the page, parse it and finally trigger UI update.
	 * Each query is run is separate thread.
	 * @param url Full URL of website to fetch
	 */
	public void runSearch(String url){
		Thread queryThread = new Thread() {
			@Override
			public void run() {
				try {
					log.info("Downloading: " + url);
					Document page = Jsoup.connect(url).timeout(TIMEOUT).get();
					log.info("Download complete. Paring...");
					parse(page);
					log.info("Parsing complete. Updating list...");
					updateList();
					log.info("List update complete.");
				}
				catch (IOException e){
					log.error("Fetching failed for url: " + url + " " + e.getMessage());
					log.error("Connection timed out.");
					JOptionPane.showMessageDialog(new JFrame(), "Connection timed out for: " + url,"Connection timed out", JOptionPane.ERROR_MESSAGE);
				}
				catch (CVEParseException e){
					log.error("Parsing failed for url: " + url + " " + e.getMessage());
					JOptionPane.showMessageDialog(new JFrame(), "Parsing failed for: " + url,"Parsing failed", JOptionPane.ERROR_MESSAGE);
				}
			}
		};
		queryThread.start();
	}

	/** 
	 * This method executes a search query for currently entered keywords in search box. It will try to download the page, parse it and finally trigger UI update.
	 * Each query is run is separate thread.
	 * 
	 */
	public void runSearch(){
		String url = url_search_prefix + searchField.getText()+ url_search_sufix;
		log.info("Running search for newest entries. URL: " + url);
		runSearch(url);
	}

	/**
	 * Parse received webpage and insert results to entries and pageNavigatorButtons.
	 * @param page Downloaded CVE search result webpage
	 * @throws CVEParseException Exception raised when parsing failed
	 */
	private void parse(Document page) throws CVEParseException{
		log.debug("Clearing entries list and buttons list");
		// Clear old entries
		entries.clear();

		log.info("Parsing CVE entries");
		try {
			// Find all CVE entries 
			Elements CVEs = page.select(css_CVE_link);
			// Parse each found entry
			for (Element CVE : CVEs){
				String number = CVE.ownText();
				
				// Set default values 
				String summary = "Not found";
				String date = "Unknown date";
				String score = "Unknown";
				
				// get element containing CVE description
				Element descriptionElement = CVE.parent().nextElementSibling();
				
				// parse summary
				Elements summaryElements = descriptionElement.select("span.label:matches(^Summary:");
				if ( !summaryElements.isEmpty() ){
					summary = summaryElements.first().parent().ownText();
					log.debug("Found summary: " + summary);
				}
				
				// parse date
				Elements dateElements = descriptionElement.select("span.label:matches(^Published:");
				if ( !dateElements.isEmpty() ){
					date = dateElements.first().parent().ownText();
					log.debug("Found date: " + date);
				}
				
				// parse CVV score
				Elements scoreElements = descriptionElement.select("span.label:matches(^CVSS Severity:");
				if ( !scoreElements.isEmpty() ){
					score = scoreElements.first().parent().ownText();
					log.debug("Found score: " + score);
				}

				log.info("Parsed list element: " + number);
				// add parsed data to storage variable
				entries.add(new CVEListEntry(number,summary,score,date));
			}

			// clear old nav buttons data
			pageNavigatorButtons.clear();
			log.info("Parsing navigation panel");
			
			// get element containing navigation buttons
			Elements navPanel = page.select(css_Page_Navigator).first().children();
			// parse each found button link
			for (Element navButton : navPanel){
				log.debug("Parsed navButton: " + navButton.ownText() + " " + navButton.attr("href") );
				pageNavigatorButtons.put(navButton.ownText(),navButton.attr("href"));
			}
			log.info("Parsing complete");
		}
		catch (Exception e){
			// Cleanup storage variables
			entries.clear();
			pageNavigatorButtons.clear();
			// Rethrow exception as CVEParseException
			throw new CVEParseException(e);
		}
	} 

	/**
	 * Update list view with data from entries and pageNavigatorButtons.
	 */
	public void updateList() {
		log.info("Updating list.");
		
		// create action listener for new buttons
		CVEListNavButtonAL actionListener = new CVEListNavButtonAL(this,pageNavigatorButtons);
		
		// execute GUI update in AWT Event Dispatcher thread
		javax.swing.SwingUtilities.invokeLater(new Runnable() {
			@Override
			public void run() { 
				// clear old list entries
				model.clear();
				// clear old page buttons
				pageNavigator.removeAll();
				// hide list in case of update failure
				scrollPane.setVisible(false);
				
				
				log.debug("List cleared. Adding new entries.");
				// based on stored data, create and add entry to the list
				for (CVEListEntry entry : entries) {
					log.debug("Adding " + entry + " to the list.");
					model.addElement(entry);
				}

				// based on stored data, create and add navigation buttons 
				for (String key : pageNavigatorButtons.keySet()){
					JButton newButton = new JButton(key);
					// disable currently selected page button
					if ( pageNavigatorButtons.get(key) == "" ){
						newButton.setEnabled(false);
					}
					newButton.addActionListener(actionListener);
					pageNavigator.add(newButton);
				}
				log.info("Adding complete. Refreshing window");
				
				// redraw GUI
				scrollPane.setVisible(true);
				pageNavigator.revalidate();
				jf.pack();
			}
		}); 
	};	
}