Abstraction from authentication might be a problem

I noticed a lot of packages in the account package for authentication. I’ve found it very very easy to set up oauth with any included package.
However, I am a bit lost on authenticating with other services that do not have a package in atmosphere. For example, on one of my applications, I want to authenticate with Battle.net, which has a node passport package but not an atmosphere package.

What is the procedure for doing this? Can I leverage some kind of OAuth package to still keep it simple?