JDK Tutorials - Herong's Tutorial Notes
Dr. Herong Yang, Version 4.32, 2006

SSL - HTTPS

Part:   1  2   3  4 

JDK Tutorials - Herong's Tutorial Notes © Dr. Herong Yang

Internationalization

Character Set and Encoding

Socket Communication

Document Object Model (DOM)

XSD Validation in Java

XSL - Transformer in Java

JCA - Private and Public Key Pairs

JCE - Secret Key

SSL (Secure Socket Layer)

SSL - Client Authentication

... Table of Contents

(Continued from previous part...)

To test HttpsHello.java, I wrote a simple HTTPS client program, HttpsClient.java: 

/**
 * HttpsClient.java
 * Copyright (c) 2005 by Dr. Herong Yang
 */
import java.io.*;
import java.net.*;
import javax.net.ssl.*;
public class HttpsClient {
   public static void main(String[] args) {
      PrintStream out = System.out;

      // Getting the default SSL socket factory
      SSLSocketFactory f = 
         (SSLSocketFactory) SSLSocketFactory.getDefault();
      out.println("The default SSL socket factory class: "
         +f.getClass());
      try {
      // Getting the default SSL socket factory
         SSLSocket c =
           (SSLSocket) f.createSocket("localhost", 8888);
         printSocketInfo(c);
         c.startHandshake();
         BufferedWriter w = new BufferedWriter(new OutputStreamWriter(
            c.getOutputStream()));
         BufferedReader r = new BufferedReader(new InputStreamReader(
            c.getInputStream()));
         w.write("GET / HTTP/1.0");
         w.newLine();
         w.newLine(); // end of HTTP request
         w.flush();
         String m = null;
         while ((m=r.readLine())!= null) {
            out.println(m);
         }
         w.close();
         r.close();
         c.close();
      } catch (IOException e) {
         System.err.println(e.toString());
      }
   }
   private static void printSocketInfo(SSLSocket s) {
      System.out.println("Socket class: "+s.getClass());
      System.out.println("   Remote address = "
         +s.getInetAddress().toString());
      System.out.println("   Remote port = "+s.getPort());
      System.out.println("   Local socket address = "
         +s.getLocalSocketAddress().toString());
      System.out.println("   Local address = "
         +s.getLocalAddress().toString());
      System.out.println("   Local port = "+s.getLocalPort());
      System.out.println("   Need client authentication = "
         +s.getNeedClientAuth());
      SSLSession ss = s.getSession();
      System.out.println("   Cipher suite = "+ss.getCipherSuite());
      System.out.println("   Protocol = "+ss.getProtocol());
   }
}

Of course, we have to run HttpsClient.java with the server's certificate in a trusted key store file: 

>\jdk\bin\java -cp . "-Djavax.net.ssl.trustStore=public.jks" 
   HttpsClient

The default SSL socket factory class: 
   class com.sun.net.ssl.internal.ssl.SSLSocketFactoryImpl
Socket class: class com.sun.net.ssl.internal.ssl.SSLSocketImpl
   Remote address = localhost/127.0.0.1
   Remote port = 8888
   Local socket address = /127.0.0.1:2408
   Local address = /127.0.0.1
   Local port = 2408
   Need client authentication = false
   Cipher suite = TLS_DHE_DSS_WITH_AES_128_CBC_SHA
   Protocol = TLSv1
HTTP/1.0 200 OK
Content-Type: text/html

<html><body>Hello world!</body></html>

The result matches the expectation perfectly.

Connecting HttpsHello.java with Internet Explorer

Now let's use Internet Explorer (IE) to connect to HttpsHello.java. First run HttpsHello.java again. 

>\jdk\bin\java -cp . HttpsHello

Server started:
Server socket class: 
   class com.sun.net.ssl.internal.ssl.SSLServerSocketImpl
   Socker address = 0.0.0.0/0.0.0.0
   Socker port = 8888
   Need client authentication = false
   Want client authentication = false
   Use client mode = false

Then run IE with https://localhost:8080, the browser will give a security alert saying that you are about to enter a secure web page. Click "OK" on the alert dialog box, you will see that the HttpsHello program prints more message, and ends with an exception: 

java.net.SocketException: Connection closed by remote host
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.checkWrite(U...
	at com.sun.net.ssl.internal.ssl.AppOutputStream.write(Unkn...
	at sun.nio.cs.StreamEncoder$CharsetSE.writeBytes(Unknown S...
	at sun.nio.cs.StreamEncoder$CharsetSE.implFlushBuffer(Unkn...
	at sun.nio.cs.StreamEncoder$CharsetSE.implFlush(Unknown So...
	at sun.nio.cs.StreamEncoder.flush(Unknown Source)
	at java.io.OutputStreamWriter.flush(Unknown Source)
	at java.io.BufferedWriter.flush(Unknown Source)
	at HttpsHello.main(HttpsHello.java:42)

At the same time, IE displays another security alert saying there is a problem with the security certificate. The issuer is not a trusted company and the certificate name does not match the server name. If you click "Yes" to continue to view the page, you will get a page-not-available error message. Because HttpsHello has already ended.

(Continued on next part...)

Part:   1  2   3  4 

Dr. Herong Yang, updated in 2006
JDK Tutorials - Herong's Tutorial Notes - SSL - HTTPS