Two-way authenticated SSL communication

This demo project shows how to create and set up two-way authenticated SSL communication over raw sockets using plain Java (and OpenSSL).

The idea for this is based on the following blog posting: http://thoughtcrime.org/blog/authenticity-is-broken-in-ssl-but-your-app-ha/ (option 1) which basically explains the following set up:

1. A private (self-signed) CA is used to create a 4096-bit signing certificate;
2. this signing certificate is used to create two signed certificates, one for the server, and one for the client;
3. both the client and server get/include a copy of the signing certificate to verify the identify of its peer.

Usage

Note that this project is intended for demo purposes, showing the abilities of two-way authenticated SSL communication. As such, it should not be used in production situations!

Basic steps to set up the certificates:

1. cd sslcert;
2. run ./create_root_cert.sh and answer the questions. For common name, use something like "Certificate Authority" or anything you like;
3. run ./export_root_cert_to_keytool.sh cacert to create the Java keystore with the signing certificate (which is the certificate trusted by both client and server);
4. run ./create_signing_request.sh server to create a signing request for the server certificate, and answer all questions. For common name, use the FQDN of the server (which is not verified at runtime, but helps you keep the certificates apart);
5. run ./sign_request.sh server to sign and create the actual certificate for the server;
6. run ./export_cert_key_to_keytool.sh server to export the server certificate and its private key to a Java keystore;
7. repeat steps 4 through 6 for the client certificate (use client as name);
8. copy the keystores to their respective locations, by running copy_keystores.sh.

Building the demo server and client

1. cd ssl.socket
2. run ant clean build to build the demo JAR. Note that you need Java7 to compile the code and create a JAR file in the generated directory.

Steps to run the server

1. run java -cp generated/ssl.socket.jar nl.lxtreme.ssl.socket.server.SslServer 9000 to start the server at port 9000 (replace 9000 with any other port if you like).

Steps to run the client

1. run java -cp generated/ssl.socket.jar nl.lxtreme.ssl.socket.client.SslClient localhost 9000 to start the client and let it communicate to the server running at localhost on port 9000 (again, change the hostname and port number to your likings).

The result will be a few lines that are written to the console(s) of both the client and server, for example:

Server started. Awaiting client...
Client (client.localhost) connected. Awaiting ping...
Ping received. Sending pong...
Pong written. Ending server...

and

Connected to server (server.localhost). Writing ping...
Ping written, awaiting pong...
Pong obtained! Ending client...

Both the client and server terminate after this.

License

This code is licensed under Apache-2.0 License.

Author

This code is written by Jan Willem Janssen, j.w.janssen@lxtreme.nl.