[BlueMatt]

(B) Used to be correct (there were some constants used in the HMAC constants which are supposed to be 1/2, but were actually 0/1, of course this makes no difference practically to security), but this has been changed in more recent versions.

[BlueMatt]

Ehh, seems they were talking about different HMAC parameters and I was thinking about the HKDF...sorry (see the moderncrypto discussion for more).