If we are going to implement this, I wouldn't want it to be strict regarding the case, one of the reasons being that LabVIEW using %x formatter outputs uppercast hex-values.
Regarding the SHA hashes, yes my intention is to offer that code in the OpenG package, however I haven't got time to write unit tests for the SHA and HMAC hashing, though I have a complete set of unit test's for AES cyper/decypher routines.
Ton