I wonder if you could override the service with a higher ranking --
@Component(
immediate = true, property = "key=auth.pipeline.pre",
service = Authenticator.class
)
public class LDAPAuth implements Authenticator {
.. this way you could implement your own logic when the process failed. The only thing is that, at least from my experience, sometimes I have tried this only to find that there are some internal classes that I can't access. There are tricks to get around this scenarion (David Nebinger wrote a great blog post outlining one way to do it) -- but looking at the import statements in that class, I don't actually see any explicit "internal" package references.
NOTE: According to the docs (in the portal.properties), the auth.pipeline.post is actually depracated and doesn't seem to be used anymore.
