A key-service failure was indistinguishable from "this disc has no key".
Five of the seven exits in the online query returned an empty result with no
log at all, and the one that did log threw away the HTTP status the service
had already handed us — so a 502, an expired token, a rate limit and a
genuine miss all produced the same single line, and the disc was reported as
having no key. Each exit now says which one it was, and the genuine miss is
logged distinctly from every failure.
Nothing new is disclosed: the address that failed the guard, the response
body and the bearer token are all still kept out of the log. The HTTP status
is the service's own response code, and the size cap is a constant.
A malformed key in a returned UK set no longer skips that one element. The
mux trusts any non-empty result as the complete forensic set, so a short set
silently omits an index; the whole reply is rejected instead.
Also make the on-disk keydb cap real. It was a metadata pre-check followed by
an unbounded read, which is not a cap: it is skipped when the stat fails, and
a FIFO or character device reports zero length, so --keydb /dev/zero passed
the guard and then read until the process was OOM-killed (NUL is valid UTF-8,
so it never even failed the decode). Read through the same take() cap the
download path already used, and add the boundary test the load path never had.
Both MAX_KEYDB_BYTES comments justified the 128 MiB ceiling by naming
the public keydb they were sized against. The number and the reasoning
are the useful part; the name is not, and it trips the pre-commit
scan. Keep the justification, drop the name.
The public UHD keydb is ~62 MiB and growing, leaving only ~2 MiB
under the old 64 MiB ceiling — updates would start failing as it grows.
128 MiB restores years of headroom while still bounding a decompression
bomb. Both cap sites (keydb.rs download/save, keydb_format.rs on-disk load)
bumped; the unrelated MKB cap in online.rs is untouched.
parse_device_key parsed node/uv/shift via from_str_radix(trim_start_matches("0x")),
a CASE-SENSITIVE strip: an uppercase 0X prefix was not removed, from_str_radix
failed, and the WHOLE device key was dropped. Now uses the canonical
libfreemkv::hex::parse_hex_u16/u32/u8. Red->green regression test added.
The key service now always returns {"UK":[...]} - an array of one for a
plain movie sample, or all 32 index-ordered variant keys for a forensic
sample. OnlineSource::query accepts both the legacy string form and the
array form, emitting one UnitKey per element (index = array position).
Re-export MIN_SAMPLE_UNITS so callers size their samples correctly.
The KEYDB-gated test that feeds real key material into libfreemkv's AACS crypto
now composes decrypt_unit + is_clean (the removed decrypt_unit_try_keys wrapper's
behaviour), unchanged semantics.
- to_keydb_cfg emits the sibling `| HC2 |` line (AACS 2.0 host cert),
the inverse of parse_host_cert_v2, so a round-trip never silently
drops v2 host certs.
- save-validation mirrors the parser's real disc-entry rule exactly: a
`0x` line counts as an entry only if it also contains ` = `, so
validating + persisting content that parses to zero usable entries
(e.g. a stray `0xDEADBEEF` line) can no longer succeed.
- disc-entry title is kept verbatim (parens and all) on parse, matching
the emit path so it round-trips.
libfreemkv deleted the aacs::boil veneer, so switch the resolve path to the
raw primitives: derive_media_key_from_{pk,dk}, derive_vuk, decrypt_unit_key
from aacs::derive, and the newtypes from aacs::types. Add a local uks_from_vuk
helper composing decrypt_unit_key. No behaviour change; fmt/clippy/test green
on Rust 1.86.
unit_keys_from now loads all stored unit keys AND the VUK/MK-derived ones, deduping by key value instead of first-hit, so a disc with partial stored UKs plus a VUK yields every declared CPS unit key. Plus keydb.cfg format round-trip (to_keydb_cfg inverse of parse).
Found via a parse->serialize->parse->serialize byte-identical check over the full
182,535-disc OEM keydb:
- Title was reduced to a parenthesised substring, truncating real titles
("Lawrence of Arabia (Restored Version) - Disc 2 - 4K Ultra HD" -> "Restored
Version"). Keep the title VERBATIM (faithful copy); display prettification is a
separate layer.
- A disc titled exactly "M" (`= M | M | 0x...`) had its title eaten as the M
field tag, dropping the real media key. Field scan now skips parts[0] (always
the title), so a title that is a tag letter (M/I/V/U/D) can't shadow a field.
- Add to_keydb_cfg_is_idempotent_on_real_keydb (KEYDB_PATH-gated): proves parse
is lossless on its own output and the serializer is deterministic.
Central round-trippable codec: parse + to_keydb_cfg in one place.
Emits HC, DK, PK, then disc entries sorted by hash. Round-trip test
(parse -> serialize -> re-parse) covers HC/DK/PK/disc. disc_id -> vid
names the field for what it is (the I-field volume ID).
unit_keys_from now resolves the Media Key in order: stored per-disc MK
-> keydb Processing Key pool (mk_from_pk vs this disc's own MKB) ->
device-key pool (mk_from_dk), then MK+VID -> VUK -> UK. MK/VUK entries
still honored directly; cross-disc MK-pool brute stays retired. Fixes the
factually-wrong justifying comment + adds PK-pool KATs.
Matthew Jackson