COMP3310 - Computer Networks (2010)

Experimenting with SSL

This weeks exercise is designed to introduce you to the Secure Sockets Layer (SSL), used by various TCP based services such as HTTPS and SSH to provide end-to-end security.

Start off by downloading openssl-examples-20020110.tar.gz somewhere in your home directory area and then uncompress and untar it:

tar xzf openssl-examples-20020110.tar.gz

Look at the README and RUNNING files, compile up the code and then test it out.

Run the sclient program against our SSL echo server running on myserver on port 6331.

Now run it against the same program running on cs.anu.edu.au on the same port. What happens and why?

Modify sclient to print out details of the certificate that has been sent back from cs.anu.edu.au.

Use tcpdump, or ethereal, to actually examine the packets going to and from the server.

Now you should write your own SSL-enabled echo server (look at modifying the wserver2 program) and try connecting to it with the sclient program.

More information about SSL and the version installed in our labs can be found here.

Also, a good introduction/tutorial on programming for SSL can be found here (pt 1) and here (pt 2) (both PDF files).