An example of TLS 1.3 client and server on Java. See details in https://blog.gypsyengineer.com/en/security/an-example-of-tls-13-client-and-server-on-java.html

TLSv13Test.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 TLSv13Test {

    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);
        }
    }
}

Hello @artem-smotrakov - thanks for preparing this example!
There are not that many samples on the Web for Java 11/TLS 1.3.

I am trying to run this example without any modification on Oracle JDK 11.0.2 and getting this:

server started on port 63855
accepted
exception: No available authentication scheme
Exception in thread "main" javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure
server stopped
	at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:128)
	at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:117)
	at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:308)
	at java.base/sun.security.ssl.Alert$AlertConsumer.consume(Alert.java:279)
	at java.base/sun.security.ssl.TransportContext.dispatch(TransportContext.java:181)
	at java.base/sun.security.ssl.SSLTransport.decode(SSLTransport.java:164)
	at java.base/sun.security.ssl.SSLSocketImpl.decode(SSLSocketImpl.java:1152)
	at java.base/sun.security.ssl.SSLSocketImpl.readHandshakeRecord(SSLSocketImpl.java:1063)
	at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:402)
	at java.base/sun.security.ssl.SSLSocketImpl.ensureNegotiated(SSLSocketImpl.java:716)
	at java.base/sun.security.ssl.SSLSocketImpl$AppOutputStream.write(SSLSocketImpl.java:970)
	at java.base/java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:81)
	at java.base/java.io.BufferedOutputStream.flush(BufferedOutputStream.java:142)
	at com.gypsyengineer.tlsbunny.jsse.TLSv13Test.main(TLSv13Test.java:26)

I will dig a bit further to understand the root cause, but wanted to just flag the issue I am experiencing.

@vkolomeyko did you get it fixed? I also got same error.

@vkolomeyko Sorry for the late reply, for some reason I missed your message.

I forgot to mention that the program needs a keystore and a truststore. Otherwise, the server can't find a certificate to authenticate itself, and as a result a SSLHandshakeException is thrown.

@phaugat7 To fix the problem, you need to set javax.net.ssl.keyStore, javax.net.ssl.keyStorePassword, javax.net.ssl.trustStore and javax.net.ssl.trustStorePassword system properties. 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

Hi @artem-smotrakov,

Thank you for the example. I am trying to send over 2^14 bytes (Updated the String message & byte[] data) but the program limits it. Is there a specific reason? Or can the code be modified to handle messages over 2^14 bytes?

Thanks.

Hi @vcheruk2

According to the spec, 2^14 is the max length of a TLSPlaintext record:

https://tools.ietf.org/html/rfc8446#section-5.1

If you need to send data that exceeds this limit, you need to split the data. Have you tried that? Do you get any exception?

I think that the default TLS implementation in Java (JSSE) should be able to split the data that exceeds the limit. If it doesn't, then it looks like a bug or a potential enhancement in JSSE.

hi @artem-smotrakov

I tried your example and it worked well. But then I turned on -Djavax.net.debug=all.
Then I see that the TLS handshake for 1.3 fails and the client tries again with TLS 1.2 ...

So the example works but it does not use TLS 1.3. I tried with open jdk 11.0.12.7 and open jdk-14.0.1.7.

Any idea whats going wrong ? When I debug I see that java does not have a cipher and protocol combination which allows to run tls 1.3.

Hi @dejpec

Then I see that the TLS handshake for 1.3 fails and the client tries again with TLS 1.2

That sounds strange. The example code enables only TLS 1.3 via setEnabledProtocols() call. I assume you didn't update the protocols variable. Furthermore, the only enabled cipher suite TLS_AES_128_GCM_SHA256 is available only in TLS 1.3.

Could you please post somewhere the output with -Djavax.net.debug=all?

Thanks artem-smotrakov for looking into. Here is the ouput file

Hi @dejpec

In the logs, I see that TLS 1.3 was negotiated:

ClientHello.java:838|Negotiated protocol version: TLSv1.3

ServerHello.java:987|Negotiated protocol version: TLSv1.3

Also, the handshake messages follow TLS 1.3 spec. For example, see EncryptedExtensions and NewSessionTicket messages that are available only in TLS 1.3.

Please note that ClientHello.client_version and ServerHello.server_version still contain "TLSv1.2". This is expected behavior. You can also notice messages that mention TLSv1.2:

SSLSocketInputRecord.java:213|READ: TLSv1.2 handshake, length = 122

I think it happens because TLSPlaintext.legacy_record_version has to be"TLSv1.2" in TLS 1.3. That's also expected behavior.