Dynamically load Bouncy Castle provider on AS 5.0.x

CXF implementation of WS-Security requires the BC provider to perform encryption. To run encryption tests in our testsuite, we need to dynamically load the BC provider (i.e.pretending it's already installed in the current JRE is not an option and adding its library to jbossws.sar deployment is not a valid solution).
The related JBWS-2098 issue test simply loads the BC provided as described here http://www.jboss.com/index.html?module=bb&op=viewtopic&t=44790 . This currently fails on AS 5.0 since the sar file is not signed, but this is probably not the only issue.