decrypt_with now takes the disc's encrypted content samples and, after
deriving the candidate unit keys, confirms at least one de-scrambles a real
aligned unit before committing them. A wrong key (a keydb VK that doesn't
match the disc, a stale UK) is rejected with AacsKeyRejected instead of
silently applying garbage unit keys. Conservative by design: with no samples
(resume / mapfile cache) it accepts as before, leaving those paths unchanged.
The KeySource trait becomes a stateful provider — next_key hands one candidate
at a time (the source owns the order) and reports exhaustion, replacing the
all-at-once resolve; errored() distinguishes a failed source from a clean
no-key.
MattJackson
e2aa9abd6d