I absolutely agree about all the openid4java dependencies, a real pain. Unfortunately, icu4j and xalan were required & they add 6+MB. Higgins is only required for InfoCard, which is not being used (I included all the deps in the pom for clariy). Only the required deps (causing ClassNotFoundExceptions) were embedded.
However, I wish I'd seen dyuproject earlier. It looks like it has all we need, and since the OpenID interaction in the handler is confined to 2 methods, I think I can easily rip out openid4java & replace with dyu - I'll give it a try.
The OpenID provider was included because I figured eventually I might have to build integration/unit tests for the handler that could be run as part of the build, non-interactively & without access to an online provider or real OpenID credentials. It would definitely make sense to split that out, at least into a testing module. Given all the library dependencies, it may not be worth it though
I'll post an updated handler shortly (with all the license bits).