/*  ShowX509Cert uses JavaPlugin1.2.2+ RSA signing to display
    details of client-side x509v1,v2,v3 certificates. Certificate
    must be in binary-der or base64 encoded format.
    Certificate details are displayed in Java console and
    textarea element of applet.
                               by M. Gallant   07/22/2001    */


import java.awt.* ;
import java.awt.event.*;
import java.io.* ;
import java.security.cert.*;
import java.net.*;

public class ShowX509Cert extends java.applet.Applet implements ActionListener {

   TextArea textArea = new TextArea (15, 75);
   private Button filebutton = new Button("Select Cert File") ;
   private Button urlbutton = new Button("Cert URL:") ;
   private TextField tf = new TextField("Enter a URL to a cert. here", 35) ;

   public void init() {
      setBackground( new Color(192,192,240) ) ;
      add(filebutton) ;
      filebutton.addActionListener(this);
      add(urlbutton) ;
      urlbutton.addActionListener(this);
      urlbutton.setBackground(Color.red) ;
      add(tf) ;
      add(textArea) ;
   }


   public void actionPerformed(ActionEvent e) {
      if ( e.getSource() == filebutton ) {
         Frame myframe = new Frame() ;
         FileDialog myfd = new FileDialog(myframe, "Select X509 Cert File ...", FileDialog.LOAD) ;
         myfd.toFront() ;
         myfd.show() ;
         String mydir = myfd.getDirectory();
         String myname = myfd.getFile() ;
         File fname = new File(mydir+myname) ;
         textArea.setText("") ;

         if ( fname.exists() ) {

            try {
               InputStream inStream = new FileInputStream(fname);
               CertificateFactory cf = CertificateFactory.getInstance("X.509");
               X509Certificate cert = (X509Certificate)cf.generateCertificate(inStream);
               inStream.close() ;
               textArea.setText("----- Certificate File: " + fname + " -----\n" + cert.toString()) ;
            } catch ( CertificateException cex ) {
               System.out.println(cex.toString());
               textArea.setText(cex.toString()) ;
            } catch ( IOException ioe ) {
              System.out.println(ioe.toString());
               textArea.setText(ioe.toString()) ;
            }

         } else {
            System.out.println("Couldn't find file: " + mydir+myname) ;
            textArea.setText("Couldn't find file: " + mydir+myname) ;
         }
         myframe.dispose() ;
      }

      if ( e.getSource() == urlbutton ) {         // if a URL certificate was specified ...
	     // BufferedInputStream buffin = null;
	// *** note that BufferedInputStream does NOT read properly with generateCertificate(BuffInpStr)
	String urlspec = tf.getText(); 
    try {
        URL url = new URL(urlspec) ;
        InputStream buffin = url.openStream();
               //  buffin = new BufferedInputStream(url.openStream(), 512) ;
       textArea.setText("Retrieving network certificate ....... \n") ;
      CertificateFactory cf = CertificateFactory.getInstance("X.509");
      X509Certificate cert = (X509Certificate)cf.generateCertificate(buffin);
      buffin.close() ;
      textArea.setText("----- Certificate URL: " + urlspec + " -----\n" + cert.toString()) ;
     } // end try

        catch (MalformedURLException mue) {
          textArea.setText("Bad URL : " + urlspec)    ;
        } 
        catch (IOException ieo) {
          textArea.setText("Problem with " + urlspec)    ;
        }
        catch (CertificateException ce) {
          textArea.setText("Problem reading " + urlspec + " URL as certificate. \n" + ce.toString() + "\n")    ;
        }
    }
   }

     /**
    * Allow this applet to run as as application as well.
    *
    * @param args command line arguments ignored.
    */
   static public void main(String args[]) {
      final ShowX509Cert applet = new ShowX509Cert();
      final Frame frame = new Frame("Show X509 Certificates");
      frame.setSize(600, 380);
      applet.init();
      frame.add(applet);
      frame.validate();
      frame.setVisible(true);
      applet.start();

      frame.addWindowListener
      (
      new java.awt.event.WindowAdapter()
      {
         /**
          * Handle request to shutdown.
          *
          * @param e event giving details of closing.
          */
         public void windowClosing(java.awt.event.WindowEvent e)
         {
            applet.stop();
            applet.destroy();
            System.exit(0);
         } // end WindowClosing
      } // end anonymous class
      ); // end addWindowListener line
   } // end main

} // end class