How can I log the SSL layer with the Apache HTTP server classes

How can I log the SSL layer with the Apache HTTP server classes

I have a custom application that is using httpcomponents-core-4.2.4 and
the SSLContext/SSLEngine with Oracle JDK to enable https.
It works fine in Windows/OSX environments.
However, it does not work in Ubuntu 12.04 with OpenJDK.
How can I enable logging for the HTTP components or the SSL classes, since
they do not provide anything to log4j logs, although the client side
httpcomponents do.
I found that there is an internal Debug instance in SSLEngineImpl, but how
do I enable it?