Verify SSL Communications Using the ssltap Tool

You can use the ssltap tool to check if the hand shake is working on your system. The tool works like an SSL proxy, showing the communications between the LDAP client and the Directory Server and the packages being exchanged. For example, using this tool you might see where the server asks for a certificate but the client does not send the certificate or where the client proposes a cipher suite that the server does not support.

Since the SSL port 636 is hard-coded on the client side, the ssltap tool run on the Directory Server, where it must list on port 636 for incoming client requests. The SSL port of the Directory Server needs to be changed to a number other than 636 while running the ssltap tool.

For example, run ssltap as follows:

ssltap -vhfsxl -p 636 localhost:637 > output.html

After running some simple LDAP request on the client, such as ldaplist, the tool should have captures some SSL packets. Stop the tool by pressing CTRL-C and view the output file in a browser window. The output data is color coded so that data sent by the client is marked in blue and data sent by the server is marked in red.