SSLExample.java

package com.gypsyengineer.tlsbunny.jsse;

import javax.net.ssl.SSLServerSocket;
import javax.net.ssl.SSLServerSocketFactory;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
import java.io.*;

/*
 * Don't forget to set the following system properties when you run the class:
 *
 *     javax.net.ssl.keyStore
 *     javax.net.ssl.keyStorePassword
 *     javax.net.ssl.trustStore
 *     javax.net.ssl.trustStorePassword
 *
 * More details can be found in JSSE docs.
 *
 * For example:
 * 
 *     java -cp classes \
 *         -Djavax.net.ssl.keyStore=keystore \
 *         -Djavax.net.ssl.keyStorePassword=passphrase \
 *         -Djavax.net.ssl.trustStore=keystore \
 *         -Djavax.net.ssl.trustStorePassword=passphrase \
 *             com.gypsyengineer.tlsbunny.jsse.TLSv13Test
 *
 * For testing purposes, you can download the keystore file from 
 *
 *     https://github.com/openjdk/jdk/tree/master/test/jdk/javax/net/ssl/etc
 */
public class SSLExample {

 private static final int delay = 1000; // in millis
 private static final String[] protocols = new String[] {
  "TLSv1.3"
 };
 private static final String[] cipher_suites = new String[] {
  "TLS_AES_128_GCM_SHA256"
 };
 private static final String message =
  "Like most of life's problems, this one can be solved with bending!";

 public static void main(String[] args) throws Exception {
  try (EchoServer server = EchoServer.create()) {
   new Thread(server).start();
   Thread.sleep(delay);

   try (SSLSocket socket = createSocket("localhost", server.port())) {
    InputStream is = new BufferedInputStream(socket.getInputStream());
    OutputStream os = new BufferedOutputStream(socket.getOutputStream());
    os.write(message.getBytes());
    os.flush();
    byte[] data = new byte[2048];
    int len = is.read(data);
    if (len <= 0) {
     throw new IOException("no data received");
    }
    System.out.printf("client received %d bytes: %s%n",
     len, new String(data, 0, len));
   }
  }
 }

 public static SSLSocket createSocket(String host, int port) throws IOException {
  SSLSocket socket = (SSLSocket) SSLSocketFactory.getDefault()
   .createSocket(host, port);
  socket.setEnabledProtocols(protocols);
  socket.setEnabledCipherSuites(cipher_suites);
  return socket;
 }

 public static class EchoServer implements Runnable, AutoCloseable {

  private static final int FREE_PORT = 0;

  private final SSLServerSocket sslServerSocket;

  private EchoServer(SSLServerSocket sslServerSocket) {
   this.sslServerSocket = sslServerSocket;
  }

  public int port() {
   return sslServerSocket.getLocalPort();
  }

  @Override
  public void close() throws IOException {
   if (sslServerSocket != null && !sslServerSocket.isClosed()) {
    sslServerSocket.close();
   }
  }

  @Override
  public void run() {
   System.out.printf("server started on port %d%n", port());

   try (SSLSocket socket = (SSLSocket) sslServerSocket.accept()) {
    System.out.println("accepted");
    InputStream is = new BufferedInputStream(socket.getInputStream());
    OutputStream os = new BufferedOutputStream(socket.getOutputStream());
    byte[] data = new byte[2048];
    int len = is.read(data);
    if (len <= 0) {
     throw new IOException("no data received");
    }
    System.out.printf("server received %d bytes: %s%n",
     len, new String(data, 0, len));
    os.write(data, 0, len);
    os.flush();
   } catch (Exception e) {
    System.out.printf("exception: %s%n", e.getMessage());
   }

   System.out.println("server stopped");
  }

  public static EchoServer create() throws IOException {
   return create(FREE_PORT);
  }

  public static EchoServer create(int port) throws IOException {
   SSLServerSocket socket = (SSLServerSocket)
   SSLServerSocketFactory.getDefault().createServerSocket(port);
   socket.setEnabledProtocols(protocols);
   socket.setEnabledCipherSuites(cipher_suites);
   return new EchoServer(socket);
  }
 }
}