I happened to stumble across crypto/store while poking around at some
other stuff, and it's unclear that the generic object (key, certificate,
CRL, etc.) store is getting used. I don't see any consumers in the
tree, and at present there only seems to be a memory-backed backend
("highly experimental", "to be used by other stores for internal
caching") implemented. I guess it's possible that someone implemented
an engine for this API, but even if they had, it doesn't seem terribly
useful if there are no consumers of the API in the tree.
Since it was added in 2003, and still has no consumers in 2015, it might
be time to declare the experiment a failure and pull the code out of the
support surface for 1.1. Is there a reason to keep it around?