online: follow libfreemkv's halt::Progress rename to Liveness

Cargo.lock: restore (accidentally changed by local patch)
tests: halt-landing tests assert Halted, not a tight wall-clock bound
2026-10-07 18:13:11 +00:00 · 2026-09-30 20:36:55 -07:00 · 2026-09-30 20:24:57 -07:00 · 2026-09-30 20:24:46 -07:00 · 2026-09-30 20:03:38 -07:00 · 2026-09-30 16:09:03 -07:00
25 changed files with 2105 additions and 1466 deletions
@@ -2,10 +2,11 @@ version: 2

 # Dependency updates land on `dev`, never on `main`.
 #
-# `main` here is a RELEASE POINTER that release.sh moves to each tag. A bot
-# commit on it would put work there that no tag contains, which is exactly the
-# state that aborted the 1.6.2 cascade at the last step -- so pointing
-# Dependabot at main would recreate that failure on a schedule.
+# `main` here is a RELEASE POINTER that freemkv's release-orchestrate.yml
+# moves to each tag. A bot commit on it would put work there that no tag
+# contains, which is exactly the state that aborted the 1.6.2 cascade at the
+# last step -- so pointing Dependabot at main would recreate that failure on a
+# schedule.
 updates:
  - package-ecosystem: cargo
    directory: /
@@ -13,9 +14,7 @@ updates:
    schedule:
      interval: weekly
    open-pull-requests-limit: 5
-    # One PR per week for the routine bumps instead of one per crate. Eight
-    # repos times a handful of crates is a volume nobody reads, and an
-    # unread PR queue is indistinguishable from no updates at all.
+    # One PR per week for the routine bumps instead of one per crate.
    groups:
      minor-and-patch:
        update-types:
@@ -23,18 +22,14 @@ updates:
          - patch
    ignore:
      # The freemkv crates depend on each other by GIT TAG, re-pinned by
-      # release.sh as part of the release commit. Dependabot cannot see that
-      # cascade, so a PR bumping one of these would fight the release process
-      # and could pin a version whose tag does not exist yet.
+      # release-orchestrate.yml in the release commit. A bot bump would fight
+      # the release cascade and could pin a tag that does not exist yet.
      - dependency-name: freemkv-unlock
      - dependency-name: libfreemkv
      - dependency-name: freemkv-keysources
      - dependency-name: freemkv-i18n
      - dependency-name: freemkv-engine

-  # The workflows are now real infrastructure -- the release cascade, the
-  # cross-platform hash matrix, the disc gate -- so their actions need the same
-  # attention as the crates.
  - package-ecosystem: github-actions
    directory: /
    target-branch: dev
@@ -47,17 +42,11 @@ updates:
          - minor
          - patch
    ignore:
-      # NOT a dependency: `dtolnay/rust-toolchain` is versioned by the RUST
-      # release it installs, and the tag we pin is the toolchain CI is pinned
-      # to on purpose -- precommit.sh runs the same one locally so a lint that
-      # passes on a developer's newer default cannot pass CI by accident.
-      #
-      # Dependabot reads those tags as semver and proposed 1.97.0 -> 1.100.0,
-      # a Rust version that does not exist. Every such PR 404s on toolchain
-      # download across all eight repos, and they regenerate weekly -- eight
-      # permanently-red PRs that promote.yml then has to special-case when it
-      # decides whether dev is green.
-      #
-      # Bumping the toolchain is a deliberate, all-eight-repos change, made by
-      # hand together with precommit.sh. There is nothing here for a bot.
+      # Versioned by the Rust release it installs; CI picks the toolchain via
+      # `toolchain:` on @master/@stable. Dependabot proposes Rust versions that
+      # do not exist. Toolchain bumps are a deliberate all-repo change.
      - dependency-name: dtolnay/rust-toolchain
+      # The org's own reusable workflows/actions. @v1 and @v2 are independent
+      # moving tags (v2 is only the comment guard), not semver releases: a
+      # "bump" from v1 to v2 would move a caller onto an OLDER guard.
+      - dependency-name: "freemkv/.github*"
@@ -94,7 +94,7 @@ jobs:
      - uses: freemkv/.github/.github/actions/checkout-siblings@v1
        with:
          checkout: libfreemkv freemkv-unlock
-          patch: libfreemkv
+          patch: libfreemkv freemkv-unlock
          self: freemkv-keysources
      # fmt runs on the MSRV pin; clippy runs on stable so new-lint debt is a
      # blocking gate the pinned toolchain would hide. Stable is installed first
@@ -125,7 +125,7 @@ jobs:
      - uses: freemkv/.github/.github/actions/checkout-siblings@v1
        with:
          checkout: libfreemkv freemkv-unlock
-          patch: libfreemkv
+          patch: libfreemkv freemkv-unlock
          self: freemkv-keysources
      - uses: dtolnay/rust-toolchain@master
        with:
@@ -149,13 +149,13 @@ jobs:
      - uses: freemkv/.github/.github/actions/checkout-siblings@v1
        with:
          checkout: libfreemkv freemkv-unlock
-          patch: libfreemkv
+          patch: libfreemkv freemkv-unlock
          self: freemkv-keysources
      - uses: dtolnay/rust-toolchain@stable
-      - uses: EmbarkStudios/cargo-deny-action@v2
-        with:
-          command: check advisories bans licenses sources
-          manifest-path: freemkv-keysources/Cargo.toml
+      - uses: taiki-e/install-action@cargo-deny
+      # Run from the repo dir so the generated .cargo/config.toml path patches apply.
+      - run: cargo deny --all-features check advisories bans licenses sources
+        working-directory: freemkv-keysources

  # This crate ships wherever freemkv and autorip ship, and it drags in all of
  # libfreemkv's platform code (SCSI transports included). Build the tests, not
@@ -182,7 +182,7 @@ jobs:
      - uses: freemkv/.github/.github/actions/checkout-siblings@v1
        with:
          checkout: libfreemkv freemkv-unlock
-          patch: libfreemkv
+          patch: libfreemkv freemkv-unlock
          self: freemkv-keysources
      - uses: dtolnay/rust-toolchain@master
        with:
@@ -209,7 +209,7 @@ jobs:
      - uses: freemkv/.github/.github/actions/checkout-siblings@v1
        with:
          checkout: libfreemkv freemkv-unlock
-          patch: libfreemkv
+          patch: libfreemkv freemkv-unlock
          self: freemkv-keysources
      - uses: dtolnay/rust-toolchain@master
        with:
@@ -250,7 +250,7 @@ jobs:
      - uses: freemkv/.github/.github/actions/checkout-siblings@v1
        with:
          checkout: libfreemkv freemkv-unlock
-          patch: libfreemkv
+          patch: libfreemkv freemkv-unlock
          self: freemkv-keysources
      - uses: dtolnay/rust-toolchain@master
        with:
@@ -9,4 +9,4 @@ concurrency:
 jobs:
  comment-guard:
    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.fork
-    uses: freemkv/.github/.github/workflows/guard-comment.yml@v1
+    uses: freemkv/.github/.github/workflows/guard-comment.yml@v2
@@ -96,7 +96,7 @@ jobs:
      - uses: freemkv/.github/.github/actions/checkout-siblings@v1
        with:
          checkout: libfreemkv freemkv-unlock
-          patch: libfreemkv
+          patch: libfreemkv freemkv-unlock
          self: freemkv-keysources
      - uses: dtolnay/rust-toolchain@master
        with:
@@ -119,7 +119,7 @@ jobs:
      - uses: freemkv/.github/.github/actions/checkout-siblings@v1
        with:
          checkout: libfreemkv freemkv-unlock
-          patch: libfreemkv
+          patch: libfreemkv freemkv-unlock
          self: freemkv-keysources
      - uses: dtolnay/rust-toolchain@stable
        with:
@@ -145,7 +145,7 @@ jobs:
      - uses: freemkv/.github/.github/actions/checkout-siblings@v1
        with:
          checkout: libfreemkv freemkv-unlock
-          patch: libfreemkv
+          patch: libfreemkv freemkv-unlock
          self: freemkv-keysources
      - uses: dtolnay/rust-toolchain@master
        with:
@@ -1,6 +1,32 @@
 # Changelog

-## [1.7.6] — 2026-09-25
+## [Unreleased]
+
+### Fixed
+
+- The online key service ignores `HTTP_PROXY`/`HTTPS_PROXY`/`ALL_PROXY`: with one set, every key lookup failed (the pinned resolver also answered the proxy's address, so the proxy request went to the key service).
+
+### Changed
+
+- `KeydbSource` hands out host certs best first, with no disc input: certs with no `Revoked in MKBv<N>` note in keydb order, then revoked ones by latest revocation. The inherent `host_certs()` and the `KeySource::host_certs` trait method both return this order; the trait ignores its `mkb` argument.
+
+### Deprecated
+
+- `KeyDb::host_certs(mkb)`: use `KeyDb::host_certs_ranked`.
+
+### Added
+
+- `KeyDb::host_certs_ranked`.
+- `check_keyserver_url` with `KeyserverUrlRejection`/`KeyserverUrlFault`: a typed Permanent vs Temporary verdict, so callers need not match `validate_keyserver_url`'s text.
+- `test-hooks` feature exposing `set_last_decode_reachability`, to test decode-verdict handling without a network.
+
+## [1.7.7] — 2026-09-26
+
+### Maintenance
+
+- Replace comment-overflow documentation with concise source contracts and README instructions; enforce the shared comment policy in CI.
+
+## [1.7.6] — 2026-09-26

 ### Changed

@@ -31,6 +31,12 @@ version = "0.23.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac07cdecf99051d9a5238b80f35af32cdeba5b336e55d957b318b50137e18da5"

+[[package]]
+name = "bitflags"
+version = "2.13.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ded4057c258ba199e2d26386d3af3780957ecaee6c4ef4041c6b4b8b97c0b06"
+
 [[package]]
 name = "block-buffer"
 version = "0.12.1"
@@ -240,6 +246,16 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"

+[[package]]
+name = "errno"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
+dependencies = [
+ "libc",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "find-msvc-tools"
 version = "0.1.11"
@@ -268,7 +284,7 @@ dependencies = [

 [[package]]
 name = "freemkv-keysources"
-version = "1.7.6"
+version = "1.7.7"
 dependencies = [
 "base64",
 "flate2",
@@ -281,7 +297,7 @@ dependencies = [

 [[package]]
 name = "freemkv-unlock"
-version = "1.7.6"
+version = "1.7.7"
 dependencies = [
 "aes",
 "base64",
@@ -487,7 +503,7 @@ checksum = "3eaf3ede3fee6db1a4c2ee091bf8a8b4dccdc6d17f656fb07896ee72867612f2"

 [[package]]
 name = "libfreemkv"
-version = "1.7.6"
+version = "1.7.7"
 dependencies = [
 "aes",
 "base64",
@@ -497,13 +513,22 @@ dependencies = [
 "memchr",
 "rayon",
 "roxmltree",
+ "rustix",
 "serde",
 "serde_json",
 "sha1",
+ "sha2",
+ "socket2",
 "tracing",
 "zip",
 ]

+[[package]]
+name = "linux-raw-sys"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a66949e030da00e8c7d4434b251670a91556f4144941d37452769c25d58a53"
+
 [[package]]
 name = "litemap"
 version = "0.8.3"
@@ -677,7 +702,7 @@ dependencies = [
 "getrandom 0.2.17",
 "libc",
 "untrusted",
- "windows-sys",
+ "windows-sys 0.52.0",
 ]

 [[package]]
@@ -686,6 +711,19 @@ version = "0.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6c20b6793b5c2fa6553b250154b78d6d0db37e72700ae35fad9387a46f487c97"

+[[package]]
+name = "rustix"
+version = "1.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "891efababe418670775f199f0d233d84843c227a0949a883ce15b37c78d6629d"
+dependencies = [
+ "bitflags",
+ "errno",
+ "libc",
+ "linux-raw-sys",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "rustls"
 version = "0.23.45"
@@ -804,6 +842,16 @@ version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9be42f50aa861c555654aa3a37f52f4b1074bacf4e48fe0ef7fa584e80f1f0f"

+[[package]]
+name = "socket2"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3d1e2c7f27f8d4cb10542a02c49005dbd6e93095799d6f3be745fae9f8fedd4"
+dependencies = [
+ "libc",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "stable_deref_trait"
 version = "1.2.1"
@@ -1021,6 +1069,12 @@ dependencies = [
 "rustls-pki-types",
 ]

+[[package]]
+name = "windows-link"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
+
 [[package]]
 name = "windows-sys"
 version = "0.52.0"
@@ -1030,6 +1084,15 @@ dependencies = [
 "windows-targets",
 ]

+[[package]]
+name = "windows-sys"
+version = "0.61.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
+dependencies = [
+ "windows-link",
+]
+
 [[package]]
 name = "windows-targets"
 version = "0.52.6"
@@ -1237,8 +1300,12 @@ dependencies = [

 [[patch.unused]]
 name = "freemkv-engine"
-version = "1.7.6"
+version = "1.7.7"

 [[patch.unused]]
 name = "freemkv-i18n"
-version = "1.7.6"
+version = "1.7.7"
+
+[[patch.unused]]
+name = "freemkv-keysources"
+version = "1.7.7"
@@ -1,6 +1,6 @@
 [package]
 name = "freemkv-keysources"
-version = "1.7.6"
+version = "1.7.7"
 edition = "2024"
 rust-version = "1.88"
 license = "MIT"
@@ -30,6 +30,15 @@ zip = { version = "8", default-features = false, features = ["deflate"] }
 # key material).
 tracing = "0.1"

+[features]
+# `set_last_decode_reachability`, for consumers' tests only (enable in dev-dependencies).
+test-hooks = []
+
+[dev-dependencies]
+# `test_util` fixtures (`decrypt_unit`, …) for this crate's tests (keys-upfront
+# KU-P1). CI resolves it through the sibling path patch.
+libfreemkv = { version = "1.7", features = ["test-util"] }
+
 [profile.release]
 lto = "thin"
 codegen-units = 1
@@ -40,7 +49,8 @@ codegen-units = 1
 # overrides it with a path patch via the gitignored .cargo/config.toml (a
 # config-level [patch.crates-io] wins over this manifest one for the same crate).
 [patch.crates-io]
-libfreemkv = { git = "https://github.com/freemkv/libfreemkv", tag = "v1.7.6" }
+libfreemkv = { git = "https://github.com/freemkv/libfreemkv", tag = "v1.7.7" }
+freemkv-unlock = { git = "https://github.com/freemkv/freemkv-unlock", tag = "v1.7.7" }

 [lints.clippy]
 uninlined_format_args = "allow"
@@ -9,6 +9,13 @@ Pluggable AACS key sources (keydb, online key service) for
 and hands libfreemkv its terminal Unit Keys via `get_unit_keys`; the library
 does all derivation.

+## Development
+
+Build API documentation with `cargo doc --no-deps --open` for source construction,
+keydb paths and online-query contracts. Run `cargo test --tests` to validate
+parsing, caching and request guards. Tests use synthetic keys and local fixtures;
+never commit real key material or credentials.
+
 ## License

 MIT — see [LICENSE](LICENSE).
@@ -1,159 +0,0 @@
-# keydb_format.rs — design notes
-
-## Full parser API retained on purpose
-
-The parser is copied verbatim, so it carries the full KeyDb/DiscEntry API
-even though this crate's consumer (`keydb.rs`) only exercises a subset
-(`load`, `find_disc`, `iter_disc_entries`, and the public fields read by
-`KeydbSource::unit_keys_from` / `KeydbSource::host_certs`). NOTE: an earlier
-revision of this comment cited a `candidates_from` function — no such
-function has ever existed in this crate; the real consumer is
-`KeydbSource::unit_keys_from` (keydb.rs), which reads `unit_keys`, `vuk`,
-`media_key` AND `vid` (`vid` is load-bearing for the MK+VID derivation the
-kat_c / kat_d KATs pin — it is NOT unused). `DiscEntry::title` is likewise
-read — by `to_keydb_cfg` and the redacting `Debug` impl — so it is not
-unused either. The genuinely unused items — `empty` and `find_vuk` — are
-part of the faithful copy and are retained rather than pruned; allow
-dead_code so the byte-for-byte copy compiles clean without diverging from
-the libfreemkv original.
-
-## ParseStats — what `KeyDb::parse` threw away
-
-The parser is fed a THIRD-PARTY file: a mirror can serve a truncated or
-byte-shifted download that is still valid UTF-8, still contains enough
-recognisable rows to pass `KeydbSource::save`'s "at least one entry" check,
-and is then atomically committed as the new keydb — after which every disc
-past the corruption point silently resolves nothing. Before this counter,
-each malformed `| DK` / `| PK` / `| HC` / `| HC2` / `0x…` row was dropped by
-an `if let Some(..) = .. { }` with no `else`, no counter and no log, so that
-file was indistinguishable from a healthy one at every layer above.
-
-The counts are logged ONCE per parse (a per-line log would be 181k lines on
-a real keydb, which is why the rate limit is "one summary", never "hide the
-count").
-
-## `KeyDb::load_counted` — same-descriptor stamp + parse
-
-Two callers need this seam, both in `crate::KeydbSource`:
-
-* The identity stamp and the bytes must come from the SAME descriptor.
-  Stat-the-path-then-load-the-path is two independent resolutions of one
-  name, so an atomic rename landing between them stored a stamp
-  describing one file next to the parsed contents of another — and the
-  cache then served that pairing until the stamp changed again. `fstat`
-  on the open handle cannot be pointed at a different inode.
-* The rejection counts have to be RETAINED, not just logged, so a cache
-  hit can re-emit them.
-
-## `to_keydb_cfg` — trailing-comment placement
-
-The trailing `; <comment>` (MKB version / volume size / UHD) is emitted
-ONLY after a `U` (unit-keys) field — that is the one place the parser
-splits the value on `;`. Gluing a comment onto an `M`/`I`/`V` value would
-make `parse_hex16` reject the whole field, so a comment-bearing entry that
-has no unit keys drops its comment (keys always survive; the metadata is a
-derivable hint). Real per-disc rows that carry metadata also carry keys.
-
-## `parse_disc_entry` title handling
-
-Title = everything between `= ` and the first ` | ` field (or the trailing
-`;` comment), kept VERBATIM (trimmed). This is a FAITHFUL copy of the keydb
-title, so it must round-trip exactly: a previous version extracted a `(...)`
-substring as a "display title", but that TRUNCATED real titles that
-legitimately contain parentheses ("Lawrence of Arabia (Restored Version) –
-Disc 2 …" → "Restored Version") and broke serialize→parse idempotence.
-Display prettification, if wanted, belongs in the title-display layer, NOT
-this codec.
-
-## Real-data test notes
-
-`to_keydb_cfg_is_idempotent_on_real_keydb`: parse the full keydb -> serialize
-(S1) -> parse S1 -> serialize again (S2). S1 MUST equal S2 byte-for-byte.
-This is the right invariant: a raw keydb.cfg has formatting variance
-(whitespace, optional fields, comment style) that our CANONICAL serializer
-normalizes, so `text == to_keydb_cfg` is NOT expected — but once normalized,
-a re-load+re-serialize must be stable. Idempotence here proves `parse` is
-lossless on its own output and `to_keydb_cfg` is deterministic. Also asserts
-no rows are dropped. It used to carry no `#[ignore]` and `return` early when
-`KEYDB_PATH` was unset — so CI ran it, asserted NOTHING about 181k-entry
-behaviour, and reported green. A skip has to be visible in the test output
-to mean anything, and an ignored test that is RUN without its fixture must
-fail loudly rather than silently pass.
-
-`real_keydb_path`: the old pattern (`match keydb_path() { Some(p) => p, None
-=> return }`) on a non-ignored test is the worst of both worlds: CI ran the
-test, asserted nothing, and reported success. These tests are `#[ignore]`d,
-so running one at all is an explicit request — and an explicit request with
-no fixture must fail, not quietly pass.
-
-## `load_counted_reads_the_handle_not_the_path` test
-
-`load_counted` must read the HANDLE it was given, never re-resolve the
-path. `KeydbSource::cached_db` stamps the open file with `fstat` and then
-parses from that same descriptor precisely so the recorded identity and
-the parsed bytes cannot describe two different files; the moment this
-function re-opens the path, that guarantee is gone and an atomic rename
-landing in between stores one file's stamp beside another file's keys —
-a mismatch the cache then serves as if it were valid.
-
-The race itself cannot be scheduled deterministically in-process, so the
-SEAM is what is pinned: with the path already replaced, the handle's
-contents must still win. Catches the mutation that restores an internal
-`File::open(path)`.
-
-## `host_cert_debug_is_redacted_including_the_sibling_wrapper` test
-
-The SIBLING type. `KeyDb`'s hand-written `Debug` prints `host_certs_len`, so
-it protects the whole-db rendering and nothing else — `KeyDb::host_certs` is
-a public field, and `{:?}` on ONE element of it walks a completely different
-code path: `KeydbHostCert`'s derive, then `HostCert`'s impl. That path
-carries the AACS host PRIVATE key, the only key material in the crate that
-authenticates US rather than opening a disc.
-
-It is safe today only because `libfreemkv::HostCert` hand-writes a redacting
-`Debug` (`aacs::types`, `private_key: "<redacted>"` + `certificate_len`) —
-an EXTERNAL guarantee this crate silently inherits through the derive, with
-nothing on this side pinning it. This test pins it: it catches a libfreemkv
-upgrade that swaps that impl for `#[derive(Debug)]`, which would leak the
-host private key out of this crate's public API with no diff in this
-repository at all.
-
-Rendered three ways because callers reach the cert three ways: the whole
-`Vec` (`db.host_certs`), one element, and the inner `HostCert` a caller
-gets back from `KeyDb::host_certs(mkb)`.
-
-## KEYDB-parser integration tests relocated from libfreemkv
-
-These exercise the parser (`KeyDb::load`) end-to-end against a real
-keydb.cfg and feed its material into libfreemkv's AACS crypto
-(`derive_vuk`, then `decrypt_unit` + `is_clean_ts`). They live here now
-that the parser lives here. All are `KEYDB_PATH`-env-gated and no-op in CI
-when the env is unset; they must still COMPILE.
-
-## `test_decrypt_real_unit` — no-decrypt outcome
-
-Reaching the fallback path is the EXPECTED outcome for the AACS 2.0 (BEE)
-sample this test was written against: the unit is still bus-encrypted, so
-no unit key alone can open it. That makes "no key worked" an unusable
-assertion on its own — which is exactly why this test used to end in an
-`eprintln!` and fall off the end, i.e. pass unconditionally. A no-op
-`decrypt_unit`, an `is_clean` stuck at `false`, or a parser that yielded
-zero keys would all have produced this same clean exit.
-
-What CAN be asserted regardless of the sample: the pipeline actually ran,
-and the decrypt primitive actually transformed the bytes.
-
-## Hand-written redacting `Debug`
-
-Key material must never reach a log, a panic message, or a bug report. Both
-`KeyDb` and `DiscEntry` carry raw AACS key bytes, and both are public API, so
-a `#[derive(Debug)]` on either is a leak of the crown jewels: `{:?}` on a
-loaded `KeyDb` printed every processing key plus every disc's Media Key,
-VID, VUK and Unit Keys. libfreemkv's equivalent types (`aacs::types`:
-`DeviceKey`, `HostCert`, `Vid`, `MediaKey`, `Vuk`, `ProcessingKey`,
-`UnitKey`, its own `DiscEntry`) all hand-write a redacting `Debug` for
-exactly this reason; this crate's copy of the parser dropped that
-convention when it was relocated. These restore it, field-for-field in the
-same style (`<redacted>` for key bytes, a `_len` for key-bearing
-collections). Pinned by `keydb_debug_is_redacted` /
-`disc_entry_debug_is_redacted`.
@@ -1,432 +0,0 @@
-# `keydb.rs` design notes
-
-Long-form rationale moved out of `src/keydb.rs` doc comments to satisfy the
-repo's comment-guard line caps. Each section is pointed to from the file by a
-one-line `// See docs/keydb.md#<anchor>` comment.
-
-## candidate-order
-
-Full derivation path this source walks, cheapest-first:
-
-1. per-disc **Unit Keys** (hash hit) → returned terminal, no derivation.
-2. per-disc **VUK** (hash hit) → `uks_from_vuk` over the disc's encrypted
-   title keys.
-3. a **Media Key**, then `derive_vuk` → `uks_from_vuk`. The MK comes from, in
-   order: the disc's stored MK (hash hit); the keydb's **Processing Key**
-   pool walked against THIS disc's MKB via `derive_media_key_from_pk`; or the
-   device-key pool via `derive_media_key_from_dk`. The PK and DK pools
-   resolve the Media Key WITHOUT a VID; the final `derive_vuk` still needs
-   one. The VID is the unlocker's physical VID (`ResolveCtx::vid`) when
-   present, else the keydb entry's OWN stored VID (the `I` field, `vid`) for
-   the non-physical / ISO path. With no VID from either source the MK path
-   cannot complete — return nothing.
-
-The cross-disc MK-pool brute (trying OTHER discs' stored media keys against
-this disc) stays RETIRED: every MK path here is anchored to the matched
-disc's own MKB or stored material.
-
-The library still OWNS the crypto; this source owns only which primitive to
-call with which material. Returning an empty `Vec` is a genuine "no key for
-this disc here".
-
-## file-identity
-
-`(len, modified)` ALONE IS NOT AN IDENTITY. mtime is stored at whole-second
-resolution on HFS+, on many container overlays and on most network
-filesystems, so a writer that replaces `keydb.cfg` within the same second
-with a file of the same byte length leaves `(len, modified)` bit-identical —
-and the cache then serves the superseded parse for the rest of the process's
-life. For a key database that is not a stale page: it is serving retired or
-since-corrected keys while reporting success. The writers that hit this are
-real and named in this crate's own docs: the daily-refresh job, a second
-freemkv process, an operator's editor, a sync tool.
-
-Two independent discriminators close it:
-
-1. `dev` + `ino`. Every writer that publishes ATOMICALLY (temp file, fsync,
-   rename — what `KeydbSource::save` does, and what any correct publisher
-   does) creates a NEW inode, so the stamp differs immediately and
-   unconditionally, whatever the clock or the mtime resolution did. Zero on
-   platforms without them (see `FileStamp::of`), which costs nothing: rule 2
-   stands alone.
-2. A freshness rule on the cache entry — `CacheEntry::is_settled` — which
-   covers the residual in-place rewrite that reuses the inode.
-
-What this still does NOT catch: a writer that FORGES the timestamp, i.e.
-restores an mtime equal to the cached one (`touch -t`, `rsync --times`, a
-tar/backup restore) into the SAME inode with the SAME length. Nothing short
-of hashing the content can see that, and hashing 62 MiB per lookup is
-precisely the cost the cache exists to remove (~141 ms × ≥3 loads per rip).
-`KeydbSource::save` therefore keeps invalidating the cache directly, so the
-one write path this crate owns never depends on any of the above.
-
-## settle-proof
-
-Whether a cache entry's stamp can be TRUSTED to change if the file changes.
-
-The proof, for a filesystem storing mtime at granularity `G`: suppose this
-entry was stamped at `stamped_at` with `stamped_at - modified >= G`, and some
-writer later rewrites the file in place at wall time `T > stamped_at`. The
-recorded mtime `m'` of that write is within one granule of `T`, so
-`m' >= T - G > stamped_at - G >= modified`. Hence `m' != modified` and the
-stamp DOES change. The ambiguous window is therefore exactly the one where
-the cached entry was stamped less than `G` after the file's own mtime — i.e.
-we looked at the file while it was still "hot" — and in that window the
-entry is refused and the file is re-read. Once the file has been quiet for
-`G`, its entry settles and the cache is fully effective again.
-
-Cost: after every keydb write, lookups re-parse for up to `G` (2 s). The
-published keydb is rewritten daily, so that is ~2 s of re-parsing per day
-against a cache that saves ~420 ms per rip.
-
-`modified: None` (a filesystem that reports no mtime) never settles: the only
-two discriminators left would be size and inode, so the entry is re-read
-every time rather than being trusted on a weaker basis.
-
-CLOCK CAVEAT: `stamped_at` is the local clock and `modified` is the
-filesystem's. On a network share whose server clock runs AHEAD of the
-client's by more than `G`, entries never settle (safe: more re-parsing). A
-server clock BEHIND the client's makes an entry settle early, which re-opens
-the same-second window it closes — the inode rule (1) is what covers the
-realistic writers there.
-
-## keydbsource-cache
-
-`KeydbSource` caches the parsed database behind the file's identity stamp.
-The published keydb is ~62 MiB / ~181k entries and a single AACS-cert rip
-parses it repeatedly — `host_certs()` for the drive handshake (freemkv's
-`pipe.rs`/`engine.rs`, autorip's `keysource.rs` each build their own source),
-then the trait `host_certs(mkb)` during resolution, then `get_unit_keys` —
-and every one of those calls used to re-read all 62 MiB from disk and
-re-parse it from scratch, because the struct held nothing but a `PathBuf`.
-
-A keydb replaced underneath this source is picked up on the next call, with
-ONE stated exception: a writer that rewrites the file in place, into the
-same inode, at the same byte length, having restored the previous mtime
-exactly (`touch -t` / `rsync --times` / a backup restore). Everything else —
-any atomic rename, any length change, any real clock advance — changes the
-stamp. `FileStamp` and `CacheEntry::is_settled` carry the full argument and
-the clock caveats; do not weaken either without re-reading them. (The
-earlier wording here — "an externally replaced keydb is still picked up" —
-was simply false for a same-second, same-length replacement, which is the
-common shape of a daily-refresh job on a whole-second-mtime filesystem.)
-
-MEMORY RESIDENCY (accepted, and deliberately recorded rather than fixed
-here): a hit keeps the entire parsed keydb — every disc's Media Key / VID /
-VUK / Unit Keys, the processing- and device-key pools, and the host-cert
-PRIVATE keys — resident for the process's life, where the pre-cache code
-held one parse transiently. Nothing in this crate zeroizes on drop, so that
-material was always exposed to a core dump or a swapped page; the cache
-widens the WINDOW, it does not create the class. Closing it properly means
-zeroize-on-drop across `KeyDb`, `DiscEntry` and libfreemkv's `aacs::types`
-(which owns most of the buffers) — a cross-crate change, tracked separately,
-NOT smuggled in behind a cache fix.
-
-## cached-db-one-open
-
-Errors are the same ones `KeyDb::load` produces, unchanged: a missing file
-is `NotFound` (the documented benign case), an over-cap or non-UTF-8 file is
-`InvalidData`. The stamp costs an `fstat`, not a 62 MiB read.
-
-ONE OPEN, ONE IDENTITY. The file is opened once and both the stamp (`fstat`
-on that handle) and, on a miss, the bytes come from it. The previous shape —
-`std::fs::metadata(path)` and then a separate `KeyDb::load(path)` — resolved
-the path TWICE with no atomicity between them, so a rename landing in the
-gap cached the new file's stamp beside the old file's contents (or the
-reverse); the pairing was then served, looking perfectly valid, until the
-stamp changed again. The stamp is read BEFORE the bytes on purpose: a write
-racing the read then leaves the OLD stamp cached, which the next call
-detects, whereas stamping afterwards would file torn content under a
-fresh-looking identity and pin it.
-
-## cached-db-reemit
-
-Re-emit the parser's rejection summary on EVERY hit, not just on the parse
-that produced it. `KeyDb::parse` is what logs it, and a hit skips `parse`
-entirely — so a daemon that cached a corrupt keydb logged its rejected-row
-counts exactly once, at whatever moment it first read the file, and then
-served that same damaged database to every later rip in silence. Repetition
-is the correct failure mode here: the line is emitted only when the file
-really does have rejected or duplicate rows, and a warning an operator can
-still see on the tenth rip is worth more than one they had to catch on the
-first.
-
-## load-failure
-
-A MISSING keydb is the documented benign case: the app may simply not have
-one, another source may hold the key, and "no keydb" is genuinely "no key
-here". Everything else is NOT that: `InvalidData` is a keydb over the
-128 MiB cap or one that is not valid UTF-8 — i.e. corrupt, truncated, or a
-half-finished download — and a permission/IO failure means the file could
-not be read at all. Reporting either as an empty result made a broken keydb
-indistinguishable from "this disc has no key" (the same conflation as the
-seven-hour 502), with no log to notice it by. Both are now logged AND
-surfaced as errors so the resolver reports a source failure instead of
-`E7022`.
-
-## save-mirror-parse
-
-Mirror `KeyDb::parse`'s disc-entry rule EXACTLY by CALLING it
-(`is_disc_entry_line`), so `save()` never validates + persists content that
-parses to zero usable entries (e.g. a stray "0xDEADBEEF" comment line) and
-the two can no longer drift — they did drift once already, on the `0X` case
-rule.
-
-## unit-keys-from
-
-CPS-unit numbering: a returned `UnitKey::idx` is the POSITIONAL index
-libfreemkv's `resolve_and_apply` turns into the canonical CPS-unit number
-`idx + 1`. For the terminal per-disc unit-key path we therefore map the
-keydb's stored CPS number `num` to `idx = num - 1`, so the committed number
-is byte-identical to the keydb's `num` (and to what the OLD
-`Key::Unit(entry.unit_keys)` path committed). For the VUK / MK paths the
-boil primitive already yields 0-based positional indices, matching
-`parse_unit_key_ro`'s `(i + 1)` after the resolver's `+ 1`.
-
-## unit-keys-per-disc-hit
-
-Per-disc hit (most specific). `find_disc` normalizes the hash form. Without
-a matched entry this keydb has no per-disc material (Unit Keys / VUK / Media
-Key / stored VID) to anchor a derivation for the disc, so it resolves
-nothing. (The PK and DK pools are global, but the cross-disc MK-pool brute —
-trying OTHER discs' media keys against this disc — stays retired; a PK/DK
-pool only ever resolves a disc reached through its own matched entry below.)
-
-## unit-keys-union
-
-UNION every source of terminal keys, then dedup — never first-hit. A stored
-`unit_keys` list can be PARTIAL (the key-import tool only ever sampled the
-CPS units reachable from a playlist, so an orphan unit's key may be
-missing), while the per-disc VUK boils EVERY declared CPS unit. Taking the
-stored list alone (the old return-at-first-path) would shadow the VUK and
-silently drop the orphan unit's key. So gather both and keep a unique-by-key
-list: the read path tries every key per unit, so an extra or stale key is
-harmless — only a MISSING key hurts.
-
-## unit-keys-vuk-or-mk
-
-2. Per-disc VUK — one step, no VID needed; boils ALL declared units.
-3. Else a Media Key path (stored MK / PK pool / DK pool) → VUK → all
-   declared units. The MK itself carries no VID, but the final `vuk_from_mk`
-   needs one: physical (unlocker) VID first, else the entry's stored VID
-   (`I` field), else cannot derive. Either branch yields the COMPLETE
-   declared set, so we take the first that resolves (VUK preferred —
-   cheapest).
-
-## write-atomic
-
-keydb.cfg is the single source of AACS truth, and save/update run
-unattended (first-boot download + daily-refresh thread, with a container
-restart on every release). A bare in-place `fs::write` truncates the file
-before writing, so a SIGKILL (docker stop's grace window), OOM-kill, power
-loss, or ENOSPC mid-write would leave the keydb half-written — the prior
-good copy already gone. A truncated keydb doesn't error at write time; it
-silently breaks key resolution on every later AACS rip. Writing to a temp
-file then renaming (POSIX rename is atomic within a filesystem) means an
-interrupted update leaves the previous keydb fully intact.
-
-The fsync MUST succeed before the rename: a `sync_all` failure (ENOSPC,
-ESTALE on the bind-mounted volume) means the kernel never guaranteed the
-bytes reached stable storage, so publishing them via rename would defeat
-crash-safety. The temp name is unique per call (pid + monotonic counter) so
-a concurrent update can't share a fixed temp path and rename a mangled file
-over the keydb.
-
-## get-unit-keys-trait
-
-A MISSING keydb is not an error — it simply yields no keys (another source
-may have them), the same as the library's own loader. A keydb that exists
-but cannot be USED (over the size cap, not UTF-8, unreadable) is a source
-failure and returns `Err`: it says nothing about whether this disc has a
-key, and reporting it as an empty result is the same looks-like-success
-failure as a 502 reported as `E7022`.
-
-The keydb carries no AACS 2.1 forensic index keys today, so it does not
-override `get_fmts_indexes` — the default (empty) opts it out, and an FMTS
-disc's forensic set comes from the online source.
-
-## host-certs-trait
-
-Expose the keydb's host certs through the trait — the OEM/AACS cert-auth
-route collects them across every source via this method. Wires the disc's
-MKB generation through for revocation filtering (the keydb parser's
-`; Revoked in MKBv<N>` annotation): a cert revoked at generation `R` is
-withheld once the disc's generation reaches `R`.
-
-## test-pinned-mtime
-
-Force a file's mtime to `PINNED_MTIME`, so two different files can be made
-bit-identical to a `(len, mtime)` stamp on purpose. The cache tests that
-matter all depend on FORCING the indistinguishable case rather than hoping
-the filesystem produces it: on APFS (nanosecond mtimes) a same-second
-replacement is otherwise detected by mtime alone, and a test that relies on
-that passes with the fix reverted — which is worth nothing.
-
-## test-committed
-
-The committed `(cps, key)` pairs libfreemkv's `resolve_and_apply` derives
-from a source's Unit Keys: positional `idx` → canonical CPS number
-`idx + 1`. The KATs compare against THIS to prove byte-identical parity with
-the OLD `Key::Unit` / resolver-derived commit.
-
-## test-mock-ctx-stub
-
-`MockCtx` implements the full `ResolveCtx` trait so it can stand in for a
-real disc, but `KeydbSource` itself never calls `title()`/`samples()` (those
-matter to the online source, not the local keydb). Exercise them directly
-so the mock's trait surface is proven correct too.
-
-## test-kat-a
-
-Here `enc_title_keys` is empty, so the VUK can't derive anything — only the
-stored list contributes, and it commits byte-identically to the stored
-`(cps, key)` pairs.
-
-## test-orphan-union
-
-Orphan-unit completeness (the real keydb bug): an entry stores only `uk1`
-(the key-import tool sampled one reachable CPS unit) but ALSO carries the
-VUK, which boils BOTH declared units. The old return-at-first-path handed
-back just `[uk1]`, shadowing the VUK and silently dropping the orphan unit.
-The union must return BOTH — the stored uk1 AND the VUK-derived second unit.
-
-## test-kat-c
-
-A hash hit with a Media Key and a physical VID (from the unlocker) derives
-`MK → VUK → UK`. The PHYSICAL VID must be used in preference to the keydb's
-stored VID — proven by giving the entry a DIFFERENT stored VID and showing
-the result tracks the physical one.
-
-## test-kat-f
-
-Owner decision #1 (AACS): a keydb Processing Key must be walked against the
-matched disc's own MKB to recover the Media Key, then driven down the full
-chain `PK → MK → VUK → UK`. The disc entry carries NO stored MK/VUK/UK — the
-only key material is a global `PK` row — and the result must be the real
-Unit Keys, byte-identical to deriving from the recovered MK.
-
-The MKB + PK use a known-answer construction (a planted PK whose derived MK
-satisfies the synthetic verify record); the constants are precomputed AES
-vectors so this crate needs no AES primitive of its own. They mirror
-libfreemkv's `boil::mk_from_pk_drives_full_chain_to_uks` KAT.
-
-## test-repeated-lookups
-
-A single AACS-cert rip drives this source at least three times — the
-scan-options builder's inherent `host_certs()`, the trait `host_certs(mkb)`
-during the handshake, then `get_unit_keys` — and each call used to re-read
-and re-parse the WHOLE file, because `KeydbSource` held nothing but a
-`PathBuf`. Measured on the real 62 MiB / 184,860-entry keydb: ~140 ms per
-parse in `--release`, i.e. ~420 ms and ~186 MiB of file reads per rip,
-against ~1 µs for a cache hit.
-
-Catches the mutation that drops the cache (every call re-parses: count 3)
-and the mutation that makes the cache unconditional (see the invalidation
-tests below).
-
-The mtime is pinned into the PAST first, because a cache entry is only
-trusted once the file has been quiet for the mtime granularity
-(`CacheEntry::is_settled`) — a keydb written microseconds ago is
-deliberately re-read. Unix-only: pinning an mtime needs `touch -t` (no
-`filetime` dependency for a test).
-
-## test-changed-keydb
-
-The cache must not go stale: a keydb replaced UNDERNEATH the source (the
-daily-refresh thread writing through a different `KeydbSource`, or an
-operator dropping in a new file) has a different size/mtime stamp and must
-be re-read. Catches the mutation that caches on first load and never
-re-stats — which would pin a rip to a keydb deleted hours earlier.
-
-## test-two-discriminators
-
-The defect both of the inode/settle tests below pin: `(len, mtime)` is not a
-file identity. An external writer — the daily-refresh job, a second freemkv
-process, an editor, a sync tool — that replaces `keydb.cfg` inside one mtime
-granule with a file of the SAME length leaves that pair bit-identical, and
-the source then serves the superseded parse for the rest of the process's
-life: retired or since-corrected keys, reported as success.
-
-Each test disables the OTHER discriminator through `mtime_granularity`, so
-neither can pass on the strength of the one it is not testing, and neither
-depends on the host filesystem's real mtime resolution (on APFS the naive
-scenario is not reproducible at all).
-
-## test-inode-rename
-
-A keydb replaced by ATOMIC RENAME — how every correct publisher, including
-this crate's own `save()`, installs a new file — must be re-read even when
-length and mtime are identical. `mtime_granularity: 0` makes every entry
-settle, so ONLY dev+ino can distinguish the two files here.
-
-Catches the mutation that drops `dev`/`ino` from `FileStamp` (the original
-`(len, modified)` stamp): the source then keeps answering with the previous
-keydb's keys.
-
-## test-inplace-rewrite
-
-A keydb rewritten IN PLACE — same inode, same length, mtime forced back to
-the same value — must still be re-read while the cached entry is too young
-to trust. `mtime_granularity` is set to a decade so nothing ever settles,
-which is the same condition a real same-second, whole-second-mtime
-replacement creates and the only way to reproduce it deterministically on a
-nanosecond-mtime filesystem.
-
-Catches the mutation that deletes the `is_settled` check from `cached_db`
-(every stamp match trusted unconditionally, which is what the original code
-did): dev, ino, len and mtime are ALL identical here, so without the
-freshness rule the source serves the old keys forever.
-
-## test-corrupt-warns
-
-`ParseStats::log` runs inside `KeyDb::parse`, and a cache hit skips `parse`
-— so once the cache landed, the rejected-row summary for a given file was
-emitted exactly ONCE for the entire life of the process, while that same
-damaged file went on being served to every subsequent rip. A long-running
-daemon (autorip) logs it at startup, the operator misses it in the startup
-noise or loses it to log rotation, and there is no second chance for as long
-as the process runs.
-
-Catches the mutation that deletes the `emit_parse_stats` call from the
-cache-HIT arm of `cached_db`: warnings would drop to 1 while the file is
-still served three times.
-
-## test-healthy-silent
-
-Catches the mutation that makes `emit_parse_stats` unconditional (drops
-`ParseStats::log`'s empty-counts early return).
-
-## test-fresh-not-trusted
-
-Catches the mutation that widens the window to something unbounded (a
-granularity of hours would re-parse 62 MiB on every lookup all day) by
-pairing with `repeated_lookups_parse_the_keydb_once`, which proves the entry
-DOES settle once the mtime is in the past.
-
-## test-save-invalidates
-
-`save()` replaces the very file this source reads, so it drops the cached
-parse ITSELF rather than trusting the (size, mtime) stamp: a same-size
-rewrite that lands inside the filesystem's timestamp granularity is the one
-change the stamp cannot see — and it is exactly the change this crate
-performs (the daily-refresh thread re-saving a keydb through the source it
-then reads from).
-
-The test forces that indistinguishable case rather than hoping for it: the
-file is written, stamped to a FIXED mtime, cached, re-saved with different
-keys of the SAME length, and stamped back to the same mtime. To the stamp
-the two files are identical, so only the explicit invalidation can produce
-the new key. Unix-only because pinning an mtime needs `touch -t` (no
-`filetime` dependency for one test).
-
-## test-corrupt-is-error
-
-`KeyDb::load` fails distinguishably for a keydb that is over the 128 MiB cap
-or not valid UTF-8 — a truncated download, a half-written file, a binary
-blob dropped in by mistake. Both used to collapse into `Ok(Vec::new())` with
-ZERO tracing, i.e. into the benign "no key for this disc" the resolver
-reports as `E7022` — the same looks-like-success failure as the seven-hour
-502. Only a MISSING file is genuinely benign.
-
-Catches the mutation that restores `Err(_) => Ok(Vec::new())`.
-</content>
@@ -1,49 +0,0 @@
-# freemkv-keysources: scope and design notes
-
-## Mechanism vs. policy
-
-Applications (autorip, the `freemkv` CLI) choose and order the key sources
-from their own config — the local-vs-online policy is just which impls they
-plug in — then resolve and hand the resulting key to `Disc::decrypt_with`.
-
-Each source resolves a disc's terminal **Unit Keys** in one shot via
-`KeySource::get_unit_keys`, driving libfreemkv's boil-down crypto primitives
-for whatever level of material it holds. Compose several with `MultiSource`
-in the caller's chosen order.
-
-Reading the encrypted content-sample units a key server validates on, and
-applying the resolved keys against a disc, is decryption *mechanism* — it
-lives in the library (`libfreemkv::resolve_and_apply`,
-`libfreemkv::read_encrypted_units`), not here.
-
-## `MultiSource` failure semantics
-
-`MultiSource::get_unit_keys` tries each inner source in order and returns the
-first non-empty Unit Key set (and `get_fmts_indexes` does the same for the
-forensic set). The caller supplies the list AND the order — local-first
-`[Keydb, Online]`, online-first `[Online, Keydb]`, etc. — so the "which
-sources, in what order" policy lives entirely with the application, not the
-library. `MultiSource` is itself a `KeySource`, so it nests and composes.
-
-**A source that could not ANSWER is not a source that answered "no key".**
-When no inner source produces keys, the composition returns `Err` if any
-inner source failed, and `Ok(empty)` only when every source genuinely
-answered and none held a key. This mirrors libfreemkv's own resolver
-(`keysource::drive_unit_keys`, which tracks an `errored` flag, and
-`source_failure`, which stamps the first failure onto the disc) — a
-composition that swallowed the `Err` would hand the resolver a clean
-`Ok(empty)`, and an outage would once again be reported to the operator as
-`E7022 No key source has a decryption key for this disc`.
-
-## `first_non_empty` ordering rule
-
-A source failure never blocks the chain (a later source is still tried, and
-a later success still wins outright, error or no error), but it is not
-forgotten either: with no keys anywhere, the FIRST failure is returned.
-First (not last) matches libfreemkv's `source_failure` rule, so the
-most-preferred source's reason is the one the operator is told about, in the
-same order the caller expressed a preference for successes.
-
-`get` selects which trait method to drive, so the base and forensic paths
-share ONE implementation of this rule and cannot drift apart — the forensic
-half carried the identical bug.
@@ -1,13 +0,0 @@
-# `MultiSource`: a source that could not answer is not a source that said no
-
-`MultiSource` used to re-collapse the Ok/Err distinction `OnlineSource` was
-engineered to draw: `if let Ok(uks) = s.get_unit_keys(ctx)` discarded every
-`Err`, so a composition whose sources ALL failed returned `Ok(Vec::new())` —
-which the resolver reports as `E7022 No key source has a decryption key for
-this disc`. That is the seven-hour-502 incident reproduced one layer up.
-
-The regression test `multi_source_reports_a_source_failure_instead_of_a_clean_no_key`
-is THE regression check, one layer up from `interpret_reply`: when no source
-holds a key AND a source could not answer, the composition must report the
-FAILURE, never a clean "no key". It catches the mutation that restores
-`if let Ok(uks) = ..` (which drops the `Err` and returns `Ok(empty)`).
@@ -1,39 +0,0 @@
-# `src/online.rs` — `OnlineSource::agent` caching
-
-## Why cache at all
-
-`query` used to build a FRESH `ureq::Agent` every call, and an FMTS disc
-makes two calls per rip (`get_unit_keys` + `get_fmts_indexes`), so it paid
-two TLS handshakes to the same host for no reason — an agent owns the
-connection pool, and a discarded agent discards the pooled, already
-negotiated TLS connection with it.
-
-## Security invariant
-
-The agent is reused ONLY when the freshly resolved + guarded address SET is
-identical to the one the cached agent is pinned to. Every query still
-re-resolves and re-runs the SSRF guard — that is the whole anti-rebinding
-defence and is deliberately not cached; what is reused is the connection,
-and only to addresses just re-validated this call.
-
-## Why the cache key is a sorted, deduped SET, not an ordered sequence
-
-`to_socket_addrs` hands back whatever order the resolver felt like, and a
-round-robin keyserver reorders its A/AAAA records on essentially every
-lookup — an ordered `==` therefore missed the cache every single time
-against exactly the deployment that most needs it, silently degrading to
-the per-query TLS handshake this field exists to avoid.
-
-Set equality is also the honest predicate: the security property being
-asserted is "these are the same validated addresses", which says nothing
-about their order. The agent itself stays pinned to the order it was BUILT
-with; that is safe because an equal set means every address it holds was
-re-resolved and re-guarded this call.
-
-## `a_reordered_but_identical_address_set_reuses_the_agent`
-
-Catches the mutation that drops the sort/dedup from `agent_for`'s key (the
-reversed order would then build a second agent) and, via the second half of
-the test, the mutation that "fixes" order-sensitivity by comparing only
-lengths or the first element — which would wrongly reuse an agent pinned to
-a DIFFERENT address.
@@ -1,41 +0,0 @@
-# `src/online.rs` — `GuardFail` classification details
-
-## Malformed-port authority
-
-A `host:port` authority whose port is not a u16 is a TYPO in the operator's
-config — `https://example.com:notaport/keys`. This used to fall back to the
-WHOLE authority as the hostname (port text included), which of course never
-resolves, so the URL surfaced as `GuardFail::Unreachable` →
-`Err(KeyServiceUnavailable)`: a standing misconfiguration reported as a
-transient outage, the exact collapse `GuardFail`'s own doc says must not
-happen, because the two halves demand OPPOSITE operator actions (fix the URL
-vs. wait).
-
-Reject it as `Config`, identical to the bracketed-IPv6 branch a few lines
-above, which already returns `Config` for an unparseable port. Silently
-substituting `default_port` would be worse still — it would ship the bearer
-token and key material to a port the operator never configured.
-
-## Guard-blocked address (`Config` arm, `resolve_and_guard`)
-
-Log THAT the URL was rejected, never WHY: the guard's message names the
-resolved address, and an internal address must not reach a log an operator
-may paste into a bug report. The static label is enough to separate
-"misconfigured/blocked key-service URL" from "this disc has no key", which
-is the only distinction the operator needs here.
-
-`error!`, not `warn!`, and `Err`, not `Ok(empty)`. This arm used to return
-`Ok(Vec::new())`, which made the PERMANENT fault quieter than the transient
-one directly above it: the service was never asked, yet the composition was
-handed a clean empty and — with no other source holding the key — told the
-operator `E7022 no key for this disc`. Same lie as the seven-hour 502, from
-a config typo that never self-heals. A failure to ask is never evidence
-about the disc, so it leaves as `Err`; `MultiSource::first_non_empty` still
-lets a later source's real key win outright, so this cannot fail a rip that
-the local keydb could have served.
-
-NOTE (reported upstream): libfreemkv has no `KeyServiceMisconfigured` code,
-so the permanent fault borrows the transient E7028. E7028's contract — "the
-source never got as far as answering the question" — is exactly true here;
-only its "transient, retry later" hint is wrong, and the `error!` log
-carries the correcting detail until a 70xx config code exists.
@@ -1,20 +0,0 @@
-# `src/online.rs` tests — pre-flight guards in `query`
-
-Each of the three guards (cleartext scheme, over-cap MKB, under-sampled)
-fires BEFORE any address is resolved and before anything is sent. None was
-exercised before these tests: a reordering that let the cleartext POST
-through would have shipped green, and that POST carries the bearer token
-plus base64 key material.
-
-Their VERDICTS differ on purpose (see docs/online-query-guards.md): the
-cleartext-scheme guard is an operator fault and yields `Err`, while the two
-input-shaped guards yield `Ok(empty)` — this source has nothing for THIS
-disc, permanently, and calling that an outage would send the operator
-waiting for nothing.
-
-The discriminator in all three: the configured host is `.test`, which RFC
-6761 guarantees never resolves. On the guarded path nothing resolves it, so
-the test touches no network and returns `Ok(empty)`. Remove the guard and
-control reaches `resolve_and_guard`, which fails as `Unreachable` ->
-`Err(KeyServiceUnavailable)` — a different Result, so the mutation cannot
-pass.
@@ -1,19 +0,0 @@
-# `src/online.rs` — `OnlineSource::query` return contract
-
-The return type draws THE distinction this source exists to draw:
-
-* `Ok(non-empty)` — the service answered with a key.
-* `Ok(empty)` — the service ANSWERED and holds no key for this disc, or this
-  source had nothing to ask with (no service configured, a misconfigured
-  URL, an over-cap MKB, too few samples). A genuine miss; the resolver moves
-  to the next source and `E7022` is the right verdict.
-* `Err(..)` — the service could not answer: unreachable, timed out, DNS
-  failed, returned 5xx, rejected the token (401/403), rate-limited (429), or
-  replied with something unreadable. NOTHING is known about whether a key
-  exists. Collapsing this into `Ok(empty)` is the bug this signature fixes:
-  a seven-hour run of HTTP 502s was reported to operators as
-  `E7022 No key source has a decryption key for this disc`, and they went
-  hunting for a VUK when the correct action was to wait.
-
-`&self`: one-shot is the resolver's contract (each source's
-`get_unit_keys` is called once), so no per-call latch is needed.
@@ -1,57 +0,0 @@
-# `src/online.rs` — `OnlineSource::query` pre-flight guards
-
-## Refusing cleartext (`http://`)
-
-The request body always carries base64 AACS key material
-(inf/mkb/units/vid) and, when configured, a bearer token in a header — so an
-`http://` POST hands both to any on-path observer, and the token is
-replayable.
-
-There is no legitimate plaintext deployment to preserve here: the address
-guard rejects loopback, RFC1918, ULA and link-local, so an `http://` URL can
-only ever reach the PUBLIC internet — the single worst case for cleartext. A
-self-hosted keyserver on a LAN is already impossible by that guard, whatever
-its scheme.
-
-Still falls THROUGH to the next key source (a local keydb) — an `Err` here
-does not block the chain, because `MultiSource::first_non_empty` returns any
-later source's non-empty key set outright and only surfaces the failure
-when nothing anywhere resolved. What it does stop is the silent case: a
-cleartext URL is the same permanent operator fault as the address-guard
-rejection (see `GuardFail`), so it gets the same verdict. Returning
-`Ok(empty)` here made "we refused to ask" indistinguishable from "the
-service answered and has no key".
-
-## The three-way skip/fault/miss line (MKB cap, sample count)
-
-Written out after the `Config`-was-quieter-than-`Unreachable` bug, in three
-parts:
-
-* NO URL AT ALL is not a fault: the operator did not configure an online
-  source, so there is nothing to report. `Ok(empty)`, silently (the first
-  guard in `query`).
-* A bad URL — wrong scheme, mistyped port, guard-blocked address — is an
-  OPERATOR FAULT. Every disc is affected, nothing was asked, and the fix is
-  to edit the config. That is `Err`.
-* An over-cap MKB or too few content samples is a property of THIS DISC's
-  inputs, not a fault: the request cannot be *formed* for this disc, so this
-  source has nothing for it and never will, whatever the operator does and
-  however long they wait. Reporting that as `KeyServiceUnavailable` would
-  send the operator waiting out an outage that does not exist — the same
-  mislabelling in the opposite direction. These stay `Ok(empty)`, and stay
-  logged.
-
-Logging on the MKB-cap skip matters: a silent empty return there is
-indistinguishable from "no key", so the real cause is surfaced (the cap is
-64 MiB, far above any real trimmed MKB).
-
-## `cleartext_http_url_is_refused_before_anything_is_sent`
-
-Catches two mutations: sending the request anyway (the host is `.test` and
-would surface as `Unreachable`, but the assertion would still hold, which is
-why `too_few_samples_skips_the_request` guards the send-path ordering
-separately) and — the one this test was rewritten for — returning
-`Ok(Vec::new())`, which made a permanent cleartext misconfiguration
-indistinguishable from a genuine miss. A later source's real key still wins
-(`MultiSource::first_non_empty`), so refusing does not fail a rip the local
-keydb can serve.
@@ -1,44 +0,0 @@
-# `src/online.rs` — SSRF guard
-
-## Threat model
-
-The keyserver URL is operator-supplied and the bearer token is confidential.
-After `validate_keyserver_url` checked the host at config time, an attacker
-who controls the keyserver's DNS can rebind it to 169.254.169.254 (cloud
-metadata) or an RFC1918 host in the window between validation and the actual
-POST, exfiltrating the key material and the Authorization token.
-
-## Defence
-
-Resolve the host once just before the POST, reject any blocked IP, and pin
-the ureq connection to those validated addresses so a subsequent DNS flip
-cannot redirect the request. Use `redirects(0)` so a public URL can't
-30x-redirect to an internal host.
-
-## Resolver wiring pitfall (`PinnedResolver`)
-
-ureq 3 replaced v2's resolver closure with the `Resolver` trait. The agent
-MUST be built through `Agent::with_parts` to take a custom one:
-`Agent::new_with_config` silently keeps the default resolver, which would
-send the request to live DNS and quietly reopen the rebinding window this
-module exists to close. That failure is invisible — it has no symptom short
-of an actual attack — so it is pinned by the test
-`hardened_agent_connects_to_the_pinned_address_not_dns`.
-
-## Why that test is structured the way it is
-
-`resolve_and_guard` VALIDATES addresses; `hardened_agent` PINS them, so a
-hostname cannot re-resolve to an internal address between validation and
-connection. The validation half is well covered by other tests — but every
-one of those still passes if the pinned resolver is never consulted, because
-none of them makes a connection. Nothing else in the file proves the agent
-honours the pin, and a mis-wired resolver fails OPEN: the connection quietly
-falls back to live DNS and the rebinding window this module exists to close
-is reopened, with no visible symptom.
-
-The discriminator: pin the agent to a loopback listener the test owns, then
-ask it for a host that CANNOT resolve — `.test` is reserved by RFC 6761 and
-never resolves in the public DNS. Only a consulted resolver can turn that
-name into a connection; a fallback to live DNS fails instead. No network is
-touched, and `query` (whose guard blocks loopback by design) is not
-involved — this drives `hardened_agent` directly.
@@ -1,13 +0,0 @@
-# `keydb.cfg` path policy (`src/paths.rs`)
-
-Key-path policy belongs with the key sources (this crate), not the library:
-libfreemkv is handed a path and reads it. The CLI/app asks here for the
-list of locations to *search* (first existing wins) and for the single
-*default* location to write to (e.g. `update-keys`/save).
-
-freemkv is a portable, standalone binary: the `keydb.cfg` lives *next to*
-the executable — `<dir of current exe>/keydb.cfg` — and nowhere else. There
-is no OS-specific config-dir lookup (`%APPDATA%`, `%USERPROFILE%\.config`,
-`$XDG_CONFIG_HOME`, `$HOME/.config`). Drop the exe and its `keydb.cfg` in
-the same folder and it works. Callers needing a custom location pass
-`--keydb PATH`, which bypasses this module entirely.
@@ -1,12 +1,10 @@
 //! `keydb.cfg` key source (source #1).
 //!
-//! Parses a local `keydb.cfg`, looks the disc up by hash, and derives the
-//! disc's terminal **Unit Keys** by composing libfreemkv's raw
-//! `aacs::derive` primitives — never re-implementing AES. The path mirrors
-//! the OLD candidate order EXACTLY, cheapest-first: per-disc Unit Keys, then
-//! VUK, then a Media Key (stored / PK pool / DK pool) via `derive_vuk`. See
-//! docs/keydb.md#candidate-order for the full path and VID rules. The
-//! library owns the crypto; this source owns only which primitive to call.
+//! Parses a local `keydb.cfg`, looks the disc up by hash, and derives the disc's terminal
+//! **Unit Keys** by composing libfreemkv's raw `aacs::derive` primitives — never
+//! re-implementing AES. The path mirrors the OLD candidate order EXACTLY, cheapest-first:
+//! per-disc Unit Keys, then VUK, then a Media Key (stored / PK pool / DK pool) via
+//! `derive_vuk`.

 use std::io::{Read, Write};
 use std::path::{Path, PathBuf};
@@ -34,14 +32,12 @@ pub struct UpdateResult {
    pub bytes: usize,
 }

-// Widest observed granularity of a filesystem's stored mtime (HFS+, many
-// container/network filesystems record whole seconds); 2 s leaves rounding
-// room. See docs/keydb.md#settle-proof for CacheEntry::is_settled's argument.
+// Widest observed granularity of a filesystem's stored mtime (HFS+, many container/network
+// filesystems record whole seconds); 2 s leaves rounding room.
 const MTIME_GRANULARITY: std::time::Duration = std::time::Duration::from_secs(2);

-// The identity of the keydb file a cache entry was parsed from. `(len,
-// modified)` alone is not an identity (see docs/keydb.md#file-identity for
-// why); `dev`+`ino` plus CacheEntry::is_settled close the gap.
+// The identity of the keydb file a cache entry was parsed from. `(len, modified)` alone is not
+// an identity; `dev`+`ino` plus CacheEntry::is_settled close the gap.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 struct FileStamp {
    /// Filesystem device id. `0` where unavailable.
@@ -92,9 +88,9 @@ struct CacheEntry {
 }

 impl CacheEntry {
-    // Whether this entry's stamp can be TRUSTED to change if the file changes.
-    // Proof, cost, and the clock caveat are in docs/keydb.md#settle-proof;
-    // don't weaken this without re-reading them.
+    // Require a settled identity before reusing a cached parse: coarse mtimes can hide
+    // in-place edits within one timestamp tick. Missing/future mtimes use the age of
+    // the observation; inode identity detects atomic replacement.
    fn is_settled(&self, granularity: std::time::Duration) -> bool {
        match self
            .stamp
@@ -117,13 +113,10 @@ impl CacheEntry {

 /// A [`KeySource`] backed by a local `keydb.cfg` file.
 ///
-/// The parsed database is CACHED behind the file's identity stamp: a single
-/// AACS-cert rip calls `host_certs()`, the trait `host_certs(mkb)`, and
-/// `get_unit_keys`, and each used to re-read + re-parse the whole
-/// ~62 MiB file. A replaced keydb is picked up on the next call, with one
-/// narrow exception; see docs/keydb.md#keydbsource-cache for that exception
-/// and the memory-residency tradeoff — do not weaken [`FileStamp`] or
-/// [`CacheEntry::is_settled`] without re-reading it.
+/// The parsed database is CACHED behind the file's identity stamp: a single AACS-cert rip calls
+/// `host_certs()`, the trait `host_certs(mkb)`, and `get_unit_keys`, and each used to re-read +
+/// re-parse the whole ~62 MiB file. A replaced keydb is picked up on the next call, with one
+/// narrow exception.
 pub struct KeydbSource {
    path: PathBuf,
    // Mutex, not RwLock: the guarded section is a stamp compare + Arc clone,
@@ -134,9 +127,8 @@ pub struct KeydbSource {
    // cache from a test, since timing is flaky and the parsed value is
    // identical either way.
    parses: AtomicUsize,
-    // The `G` of CacheEntry::is_settled, as a field so tests can isolate the
-    // two staleness discriminators one at a time (0 vs. a huge duration). See
-    // docs/keydb.md#test-two-discriminators.
+    // The `G` of CacheEntry::is_settled, as a field so tests can isolate the two staleness
+    // discriminators one at a time (0 vs. a huge duration).
    mtime_granularity: std::time::Duration,
    // Corruption summaries emitted (see emit_parse_stats). Same rationale as
    // `parses`: avoids pulling a `tracing` subscriber into dev-dependencies.
@@ -179,9 +171,8 @@ impl KeydbSource {
        self
    }

-    // The parsed keydb, from cache when unchanged (errors mirror KeyDb::load).
-    // ONE OPEN, ONE IDENTITY: stamp (fstat) and bytes share one handle. See
-    // docs/keydb.md#cached-db-one-open for why a separate metadata()+load() pair was unsound.
+    // The parsed keydb, from cache when unchanged (errors mirror KeyDb::load). ONE OPEN, ONE
+    // IDENTITY: stamp (fstat) and bytes share one handle.
    fn cached_db(&self) -> std::io::Result<Arc<KeyDb>> {
        let file = std::fs::File::open(&self.path)?;
        let stamp = FileStamp::of(&file.metadata()?);
@@ -239,9 +230,9 @@ impl KeydbSource {
        self.parses.load(Ordering::Relaxed)
    }

-    // Turn a KeyDb::load failure into this source's verdict: MISSING is the
-    // documented benign case (Ok/None); everything else is logged and
-    // surfaced as an error, not silently reported as "no key". See docs/keydb.md#load-failure.
+    // Turn a KeyDb::load failure into this source's verdict: MISSING is the documented benign
+    // case (Ok/None); everything else is logged and surfaced as an error, not silently reported
+    // as "no key".
    fn load_failure(&self, e: &std::io::Error) -> Option<Error> {
        match e.kind() {
            std::io::ErrorKind::NotFound => None,
@@ -291,8 +282,8 @@ impl KeydbSource {
        let entries = text
            .lines()
            // Mirror KeyDb::parse by running the same parsers, not a prefix check: a
-            // right-prefix row with bad hex / short cert parses to nothing, so a prefix
-            // count let junk past `entries > 0`. See docs/keydb.md#save-mirror-parse.
+            // right-prefix row with bad hex / short cert parses to nothing, so a prefix count
+            // let junk past `entries > 0`.
            .filter(|l| crate::keydb_format::is_parseable_entry_line(l))
            .count();

@@ -333,13 +324,11 @@ impl KeydbSource {
    /// live-drive scan as `DriveCredentials` for the AACS handshake. Empty if
    /// the keydb is missing/unreadable or carries no host cert.
    ///
-    /// Inherent, no-MKB form: this is used by the **scan-options** builder,
-    /// which runs before the disc's MKB generation is known, so no revocation
-    /// filtering is applied (passes `None`). The [`KeySource::host_certs`] TRAIT
-    /// method wires the real MKB generation through for revocation filtering.
+    /// Best first ([`KeyDb::host_certs_ranked`]): this is what the scan-options
+    /// builder hands the live-drive handshake as `DriveCredentials`.
    pub fn host_certs(&self) -> Vec<HostCert> {
        match self.cached_db() {
-            Ok(db) => db.host_certs(None),
+            Ok(db) => db.host_certs_ranked(),
            // No error channel here (the scan-options builder wants a list), so
            // the failure can only be LOGGED — but it must not be invisible.
            Err(e) => {
@@ -349,9 +338,8 @@ impl KeydbSource {
        }
    }

-    // Terminal Unit Keys for this disc from a parsed keydb; empty Vec = none.
-    // CPS numbering (idx = num - 1): docs/keydb.md#unit-keys-from. Thin wrapper
-    // over [`resolve_from`] for callers that want only the keys (pure, no I/O).
+    // Return terminal Unit Keys from a parsed keydb without I/O.
+    // CPS unit numbers are one-based; the returned vector uses zero-based indexes.
    fn unit_keys_from(db: &KeyDb, ctx: &dyn ResolveCtx) -> Vec<UnitKey> {
        Self::resolve_from(db, ctx).keys
    }
@@ -360,17 +348,15 @@ impl KeydbSource {
    // keyless match — WHY nothing derived, so a matched-but-underivable disc is
    // never reported as a flat "no entry" (issue #46). Pure (no I/O).
    fn resolve_from(db: &KeyDb, ctx: &dyn ResolveCtx) -> KeydbResolution {
-        // Per-disc hit (most specific); find_disc normalizes the hash form.
-        // Without a match there is no per-disc anchor, so the global PK/DK
-        // pools are never consulted. See docs/keydb.md#unit-keys-per-disc-hit.
+        // Per-disc hit (most specific); find_disc normalizes the hash form. Without a match
+        // there is no per-disc anchor, so the global PK/DK pools are never consulted.
        let entries_loaded = db.disc_entries.len();
        let Some(entry) = db.find_disc(ctx.disc_hash()) else {
            return KeydbResolution::miss(entries_loaded);
        };

-        // UNION every source of terminal keys, then dedup — never first-hit,
-        // since a stored `unit_keys` list can be PARTIAL while the VUK boils
-        // every declared unit. See docs/keydb.md#unit-keys-union.
+        // UNION every source of terminal keys, then dedup — never first-hit, since a stored
+        // `unit_keys` list can be PARTIAL while the VUK boils every declared unit.
        let mut keys: Vec<UnitKey> = Vec::new();

        // 1. Terminal Unit Keys stored in the entry — directly usable, no
@@ -406,8 +392,7 @@ impl KeydbSource {
        let mut miss_reason: Option<KeyNode> = None;

        if !enc_title_keys.is_empty() {
-            // VUK path, else MK path (stored/PK/DK) → VUK. See
-            // docs/keydb.md#unit-keys-vuk-or-mk for the VID rules.
+            // VUK path, else MK path (stored/PK/DK) → VUK.
            let derived = if let Some(vuk) = entry.vuk {
                uks_from_vuk(&vuk, enc_title_keys)
            } else {
@@ -471,10 +456,10 @@ impl KeydbSource {

        // On a match with no key: carry the specific reason if we have one, else
        // leave it empty for the library to render a bare `NoDerivableKey`.
-        let miss_path = if keys.is_empty() {
-            miss_reason.map(|n| vec![n]).unwrap_or_default()
-        } else {
-            Vec::new()
+        // KU J23: `NoVid` stays beside partial keys (the VID would derive the rest).
+        let miss_path = match miss_reason {
+            Some(n) if keys.is_empty() || n == KeyNode::NoVid => vec![n],
+            _ => Vec::new(),
        };

        KeydbResolution {
@@ -545,9 +530,8 @@ fn extract_zip(data: &[u8]) -> Result<String, Error> {
    Err(Error::KeydbInvalid)
 }

-// Write `text` to `path` crash-safely (temp file, fsync, atomic rename) so an
-// interrupted update never leaves a half-written keydb. See
-// docs/keydb.md#write-atomic for the fsync-before-rename argument.
+// Write `text` to `path` crash-safely (temp file, fsync, atomic rename) so an interrupted
+// update never leaves a half-written keydb.
 fn write_atomic(path: &Path, text: &str) -> Result<(), Error> {
    let werr = || Error::KeydbWrite {
        path: path.display().to_string(),
@@ -607,9 +591,8 @@ fn write_atomic(path: &Path, text: &str) -> Result<(), Error> {
 }

 impl KeySource for KeydbSource {
-    // Resolve this disc's base per-CPS-unit Unit Keys from the keydb. A
-    // MISSING keydb yields no keys (Ok(empty)); an UNUSABLE one is a source
-    // failure (Err) — never conflated. See docs/keydb.md#get-unit-keys-trait.
+    // Resolve this disc's base per-CPS-unit Unit Keys from the keydb. A MISSING keydb yields no
+    // keys (Ok(empty)); an UNUSABLE one is a source failure (Err) — never conflated.
    fn get_unit_keys(&self, ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, Error> {
        match self.cached_db() {
            Ok(db) => Ok(Self::unit_keys_from(&db, ctx)),
@@ -646,12 +629,10 @@ impl KeySource for KeydbSource {
        }
    }

-    // Expose the keydb's host certs through the trait, wiring the disc's MKB
-    // generation through for revocation filtering. See
-    // docs/keydb.md#host-certs-trait.
-    fn host_certs(&self, mkb: Option<u32>) -> Vec<HostCert> {
+    // The keydb's host certs, best first. `mkb` is ignored: cert selection takes no disc input.
+    fn host_certs(&self, _mkb: Option<u32>) -> Vec<HostCert> {
        match self.cached_db() {
-            Ok(db) => db.host_certs(mkb),
+            Ok(db) => db.host_certs_ranked(),
            // Vec-returning trait method: log the failure, return nothing.
            Err(e) => {
                let _ = self.load_failure(&e);
@@ -660,6 +641,12 @@ impl KeySource for KeydbSource {
        }
    }

+    // Keyed by disc hash, not by samples: asked once per resolve, not per
+    // piece (KU §2.3 step 8, N-KU10; KSK1).
+    fn answer_depends_on_samples(&self) -> bool {
+        false
+    }
+
    fn label(&self) -> &'static str {
        "keydb"
    }
@@ -674,9 +661,8 @@ mod tests {
    #[cfg(unix)]
    const PINNED_MTIME: &str = "202601011200.00";

-    // Force a file's mtime to PINNED_MTIME so two different files can be
-    // made bit-identical to a (len, mtime) stamp on purpose, rather than
-    // hoping the filesystem produces that case. See docs/keydb.md#test-pinned-mtime.
+    // Force a file's mtime to PINNED_MTIME so two different files can be made bit-identical to
+    // a (len, mtime) stamp on purpose, rather than hoping the filesystem produces that case.
    #[cfg(unix)]
    fn pin_mtime(p: &std::path::Path) {
        let ok = std::process::Command::new("touch")
@@ -765,9 +751,8 @@ mod tests {
        }
    }

-    // The committed (cps, key) pairs resolve_and_apply derives from a
-    // source's Unit Keys (idx -> idx + 1). KATs compare against THIS. See
-    // docs/keydb.md#test-committed.
+    // The committed (cps, key) pairs resolve_and_apply derives from a source's Unit Keys (idx
+    // -> idx + 1). KATs compare against THIS.
    fn committed(uks: &[UnitKey]) -> Vec<(u32, [u8; 16])> {
        uks.iter()
            .map(|u| (u.idx.saturating_add(1), u.key))
@@ -807,6 +792,19 @@ mod tests {
        assert!(!shape.vid_available);
    }

+    // KU J23: stored unit keys for SOME CPS units plus a Media Key with no VID. The stored
+    // keys come back, and the miss path still says `NoVid`: the VID would derive the rest.
+    #[test]
+    fn partial_stored_keys_with_a_media_key_and_no_vid_report_no_vid() {
+        let mut e = blank_entry(HASH);
+        e.media_key = Some([0x33u8; 16]);
+        e.unit_keys = vec![(1, [0x55u8; 16])];
+        let db = db_with(e, Vec::new());
+        let r = KeydbSource::resolve_from(&db, &ctx(HASH, vec![[0x44u8; 16]; 2], None));
+        assert_eq!(r.keys.len(), 1, "the stored key");
+        assert_eq!(r.miss_path, vec![KeyNode::NoVid]);
+    }
+
    // A hash that is NOT in the keydb is the one true miss: not matched, no
    // shape, no miss path (the library renders this as `no entry`).
    #[test]
@@ -854,9 +852,8 @@ mod tests {
        assert_eq!(shape.unit_keys_len, 1);
    }

-    // KAT (a): disc with terminal Unit Keys, no enc_title_keys. Stored
-    // terminal unit keys are returned with CPS numbering preserved. See
-    // docs/keydb.md#test-kat-a.
+    // KAT (a): disc with terminal Unit Keys, no enc_title_keys. Stored terminal unit keys are
+    // returned with CPS numbering preserved.
    #[test]
    fn kat_a_disc_with_unit_keys_is_terminal_and_preserves_cps_numbering() {
        let mut e = blank_entry(HASH);
@@ -889,9 +886,8 @@ mod tests {
        assert_eq!(committed(&got), vec![(1u32, [0xA0u8; 16])]);
    }

-    // Orphan-unit completeness (the real keydb bug): a PARTIAL stored list
-    // plus a VUK that boils BOTH declared units must return BOTH, not shadow
-    // the VUK with the partial list. See docs/keydb.md#test-orphan-union.
+    // Orphan-unit completeness (the real keydb bug): a PARTIAL stored list plus a VUK that
+    // boils BOTH declared units must return BOTH, not shadow the VUK with the partial list.
    #[test]
    fn union_partial_stored_plus_vuk_yields_all_declared_units() {
        let vuk = [0x5Au8; 16];
@@ -945,9 +941,8 @@ mod tests {
        );
    }

-    // KAT (c): MK + physical (unlock) VID derives MK -> VUK -> UK. The
-    // PHYSICAL VID must win over the keydb's stored VID. See
-    // docs/keydb.md#test-kat-c.
+    // KAT (c): MK + physical (unlock) VID derives MK -> VUK -> UK. The PHYSICAL VID must win
+    // over the keydb's stored VID.
    #[test]
    fn kat_c_disc_with_mk_uses_physical_vid_over_keydb_vid() {
        let mk = [0x77u8; 16];
@@ -1031,9 +1026,8 @@ mod tests {
        rec
    }

-    // KAT (f): disc with NO per-disc MK, resolved via the keydb PK pool
-    // (PK -> MK -> VUK -> UK) with a known-answer MKB/PK construction. See
-    // docs/keydb.md#test-kat-f.
+    // KAT (f): disc with NO per-disc MK, resolved via the keydb PK pool (PK -> MK -> VUK -> UK)
+    // with a known-answer MKB/PK construction.
    #[test]
    fn kat_f_disc_with_pk_pool_yields_uks() {
        // Planted PK and the MK it resolves to (see libfreemkv boil.rs KAT).
@@ -1167,6 +1161,15 @@ mod tests {
        assert_eq!(KeydbSource::new("/nonexistent/keydb.cfg").label(), "keydb");
    }

+    // KSK1: keyed by disc hash, so `resolve` asks it once per rip, not once per
+    // piece (KU §2.3 step 8, N-KU10).
+    #[test]
+    fn keydb_source_answer_does_not_depend_on_samples() {
+        assert!(!KeydbSource::new("/nonexistent/keydb.cfg").answer_depends_on_samples());
+        // KU J23: a keydb's VID need is per disc (its `NoVid` miss path), not blanket.
+        assert!(!KeydbSource::new("/nonexistent/keydb.cfg").uses_vid());
+    }
+
    // A stamp with no mtime (mtime-less FS) or a future mtime (clock skew) must
    // not be stuck un-settled forever — it now settles via the inode-identity
    // fallback once the observation has aged past the granularity.
@@ -1214,6 +1217,46 @@ mod tests {
        );
    }

+    /// Best-first with no disc input: unannotated certs in file order, then revoked
+    /// ones by latest revocation. The trait ignores its MKB argument.
+    #[test]
+    fn host_certs_ranked_orders_unannotated_then_latest_revocation_first() {
+        let dir = scratch("ranked");
+        let path = dir.join("keydb.cfg");
+        let hc = |marker: u8, note: &str| {
+            format!(
+                "| HC | HOST_PRIV_KEY 0x{} | HOST_CERT 0x{}{}\n",
+                "00".repeat(20),
+                format!("{marker:02x}").repeat(92),
+                note
+            )
+        };
+        let cfg = [
+            hc(0x68, " ; Revoked in MKBv68"),
+            hc(0xA1, ""),
+            hc(0x72, " ; Revoked in MKBv72"),
+            hc(0xB2, ""),
+        ]
+        .concat();
+        std::fs::write(&path, cfg).unwrap();
+        let src = KeydbSource::new(&path);
+        let markers =
+            |certs: Vec<HostCert>| -> Vec<u8> { certs.iter().map(|c| c.certificate[0]).collect() };
+        let want = vec![0xA1, 0xB2, 0x72, 0x68];
+        assert_eq!(
+            markers(src.host_certs()),
+            want,
+            "inherent (production credentials)"
+        );
+        assert_eq!(
+            markers(KeySource::host_certs(&src, Some(99))),
+            want,
+            "trait ignores mkb"
+        );
+        assert_eq!(markers(KeySource::host_certs(&src, None)), want);
+        std::fs::remove_dir_all(&dir).ok();
+    }
+
    /// No keydb → no host credentials, not an error (inherent and trait forms).
    #[test]
    fn host_certs_empty_when_keydb_missing() {
@@ -1223,8 +1266,8 @@ mod tests {
        assert!(KeySource::host_certs(&src, Some(68)).is_empty());
    }

-    /// The TRAIT `host_certs` surfaces a `| HC |` row and now wires the MKB
-    /// generation through. Placeholder all-zero material (never a real key).
+    /// The TRAIT `host_certs` surfaces a `| HC |` row for any `mkb` argument.
+    /// Placeholder all-zero material (never a real key).
    #[test]
    fn trait_host_certs_returns_keydb_hc_row() {
        let dir = std::env::temp_dir().join(format!("fmk_hc_{}", std::process::id()));
@@ -1246,9 +1289,9 @@ mod tests {
        std::fs::remove_dir_all(&dir).ok();
    }

-    // Caching: the 62 MiB / 181k-entry keydb is parsed ONCE. A single
-    // AACS-cert rip drives this source at least three times; the mtime is
-    // pinned into the PAST first, since an entry is only trusted once settled. See docs/keydb.md#test-repeated-lookups.
+    // Caching: the 62 MiB / 181k-entry keydb is parsed ONCE. A single AACS-cert rip drives this
+    // source at least three times; the mtime is pinned into the PAST first, since an entry is
+    // only trusted once settled.
    #[cfg(unix)]
    #[test]
    fn repeated_lookups_parse_the_keydb_once() {
@@ -1277,9 +1320,8 @@ mod tests {
        );
    }

-    // The cache must not go stale: a keydb replaced UNDERNEATH the source has
-    // a different size/mtime stamp and must be re-read. See
-    // docs/keydb.md#test-changed-keydb.
+    // The cache must not go stale: a keydb replaced UNDERNEATH the source has a different
+    // size/mtime stamp and must be re-read.
    #[test]
    fn a_changed_keydb_file_is_reparsed() {
        let dir = scratch("cache-stamp");
@@ -1306,9 +1348,9 @@ mod tests {
        assert_eq!(src.parse_count(), 2, "one parse per distinct file");
    }

-    // Two stale-cache discriminators, tested ONE AT A TIME (each test
-    // disables the other via `mtime_granularity`). Discriminator 1, the
-    // inode: an ATOMIC RENAME must be re-read even with identical length and mtime. See docs/keydb.md#test-inode-rename.
+    // Two stale-cache discriminators, tested ONE AT A TIME (each test disables the other via
+    // `mtime_granularity`). Discriminator 1, the inode: an ATOMIC RENAME must be re-read even
+    // with identical length and mtime.
    #[cfg(unix)]
    #[test]
    fn a_same_length_same_mtime_rename_is_still_re_read() {
@@ -1343,9 +1385,8 @@ mod tests {
        assert_eq!(src.parse_count(), 2, "the replacement must be re-parsed");
    }

-    // Discriminator 2, the settle window: a keydb rewritten IN PLACE (same
-    // inode/length, mtime forced back) must still be re-read while too young
-    // to trust. See docs/keydb.md#test-inplace-rewrite.
+    // Discriminator 2, the settle window: a keydb rewritten IN PLACE (same inode/length, mtime
+    // forced back) must still be re-read while too young to trust.
    #[cfg(unix)]
    #[test]
    fn an_in_place_rewrite_under_an_unsettled_stamp_is_still_re_read() {
@@ -1389,9 +1430,8 @@ mod tests {
        );
    }

-    // A corrupt-but-parseable keydb must keep saying so on EVERY hit, not
-    // just the parse that produced the summary (a cache hit skips `parse`).
-    // See docs/keydb.md#test-corrupt-warns.
+    // A corrupt-but-parseable keydb must keep saying so on EVERY hit, not just the parse that
+    // produced the summary (a cache hit skips `parse`).
    #[cfg(unix)]
    #[test]
    fn a_corrupt_keydb_warns_on_every_lookup_not_only_on_the_parse() {
@@ -1429,9 +1469,8 @@ mod tests {
        );
    }

-    // A HEALTHY keydb must stay silent — the re-emission above must not turn
-    // into a per-lookup log line for every operator with an intact file. See
-    // docs/keydb.md#test-healthy-silent.
+    // A HEALTHY keydb must stay silent — the re-emission above must not turn into a per-lookup
+    // log line for every operator with an intact file.
    #[cfg(unix)]
    #[test]
    fn a_healthy_keydb_warns_on_no_lookup() {
@@ -1455,9 +1494,8 @@ mod tests {
        );
    }

-    // The cost side of the settle rule, asserted as a decision: a keydb
-    // written just now is re-read on every lookup until quiet for the
-    // granularity. See docs/keydb.md#test-fresh-not-trusted.
+    // The cost side of the settle rule, asserted as a decision: a keydb written just now is
+    // re-read on every lookup until quiet for the granularity.
    #[test]
    fn a_freshly_written_keydb_is_not_trusted_from_cache() {
        let dir = scratch("cache-fresh");
@@ -1486,9 +1524,8 @@ mod tests {
        );
    }

-    // `save()` replaces the very file this source reads, so it drops the
-    // cached parse ITSELF rather than trusting the (size, mtime) stamp — the
-    // one change the stamp cannot see. See docs/keydb.md#test-save-invalidates.
+    // `save()` replaces the very file this source reads, so it drops the cached parse ITSELF
+    // rather than trusting the (size, mtime) stamp — the one change the stamp cannot see.
    #[cfg(unix)]
    #[test]
    fn save_invalidates_the_cache_even_when_the_file_stamp_is_unchanged() {
@@ -1522,9 +1559,8 @@ mod tests {
        );
    }

-    // A corrupt keydb is a source FAILURE, not "this disc has no key": both
-    // used to collapse into Ok(Vec::new()) with ZERO tracing. Only a MISSING
-    // file is genuinely benign. See docs/keydb.md#test-corrupt-is-error.
+    // A corrupt keydb is a source FAILURE, not "this disc has no key": both used to collapse
+    // into Ok(Vec::new()) with ZERO tracing. Only a MISSING file is genuinely benign.
    #[test]
    fn a_corrupt_keydb_is_an_error_not_an_empty_answer() {
        let dir = scratch("corrupt");
@@ -5,8 +5,6 @@
 //! logic is identical; the only deviation is [`KeyDb::load`], which returns a
 //! standalone [`std::io::Result`] here instead of `libfreemkv::error::Result`
 //! (so the format crate carries no dependency on libfreemkv's error type).
-//
-// See docs/keydb-format.md — why the full parser API (incl. dead_code items) is retained.
 #![allow(dead_code)]

 use std::collections::HashMap;
@@ -49,9 +47,7 @@ pub struct KeyDb {
    pub disc_entries: HashMap<Arc<str>, DiscEntry>,
 }

-// Key material must never leak via `{:?}`; both types below carry raw AACS
-// key bytes. See docs/keydb-format.md for why these hand-write a redacting
-// `Debug` instead of deriving it. Pinned by `keydb_debug_is_redacted` / `disc_entry_debug_is_redacted`.
+// Key material must never leak via `{:?}`; both types below carry raw AACS key bytes.

 impl std::fmt::Debug for KeyDb {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -173,9 +169,7 @@ pub(crate) fn parse_hex20(s: &str) -> Option<[u8; 20]> {
    libfreemkv::hex::parse_hex_fixed::<20>(s)
 }

-// What `KeyDb::parse` threw away, by reason. See docs/keydb-format.md — why
-// this counter exists (silent corruption on a third-party keydb) and why
-// it's logged once per parse rather than per-line.
+// What `KeyDb::parse` threw away, by reason.
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
 pub(crate) struct ParseStats {
    /// `| DK` rows that parsed as neither a positioned nor an orphan device key.
@@ -233,13 +227,12 @@ pub(crate) fn is_disc_entry_line(line: &str) -> bool {
    (line.starts_with("0x") || line.starts_with("0X")) && line.contains(" = ")
 }

-/// True when `line` is a row `KeyDb::parse` would actually ACCEPT into the db —
-/// a disc row OR a DK/PK/HC/HC2 row that its real parser accepts, not merely one
-/// carrying the right `| XX` prefix. `KeydbSource::save`'s "won't persist
-/// unparseable content" guard counts entries with THIS, so a syntactically
-/// prefixed but malformed DK/PK/HC row (right prefix, bad hex/short cert) can no
-/// longer inflate the entry count past the `entries > 0` check. Mirrors the
-/// dispatch in [`KeyDb::parse_counted`] exactly. See docs/keydb.md#save-mirror-parse.
+/// True when `line` is a row `KeyDb::parse` would actually ACCEPT into the db — a disc row OR a
+/// DK/PK/HC/HC2 row that its real parser accepts, not merely one carrying the right `| XX`
+/// prefix. `KeydbSource::save`'s "won't persist unparseable content" guard counts entries with
+/// THIS, so a syntactically prefixed but malformed DK/PK/HC row (right prefix, bad hex/short
+/// cert) can no longer inflate the entry count past the `entries > 0` check. Mirrors the
+/// dispatch in [`KeyDb::parse_counted`] exactly.
 pub(crate) fn is_parseable_entry_line(line: &str) -> bool {
    let line = line.trim();
    if line.is_empty() || line.starts_with(';') || line.starts_with('#') {
@@ -412,9 +405,7 @@ impl KeyDb {
        Ok(db)
    }

-    // `Self::load` from an ALREADY-OPEN file, without the log. See
-    // docs/keydb-format.md — why the same descriptor must supply both the
-    // identity stamp and the bytes, and why rejection counts are retained here.
+    // `Self::load` from an ALREADY-OPEN file, without the log.
    pub(crate) fn load_counted(
        f: std::fs::File,
        path: &std::path::Path,
@@ -486,6 +477,7 @@ impl KeyDb {
    /// is `None` the disc's generation is unknown and cannot be filtered, so
    /// every cert is returned; certs with no revocation annotation are always
    /// returned.
+    #[deprecated(note = "use host_certs_ranked; host cert selection takes no disc input")]
    pub fn host_certs(&self, mkb: Option<u32>) -> Vec<HostCert> {
        self.host_certs
            .iter()
@@ -498,6 +490,19 @@ impl KeyDb {
            .collect()
    }

+    /// Every host cert, best first, with no disc input: certs with no `Revoked in
+    /// MKBv<N>` note in file order, then revoked ones by latest revocation (a later
+    /// revocation is the better bet without knowing the disc's generation).
+    pub fn host_certs_ranked(&self) -> Vec<HostCert> {
+        let mut ranked: Vec<&KeydbHostCert> = self.host_certs.iter().collect();
+        // Stable sort: ties (every unannotated cert, equal revocations) keep file order.
+        ranked.sort_by_key(|hc| {
+            let r = hc.revoked_at_mkb;
+            (r.is_some(), std::cmp::Reverse(r.unwrap_or(0)))
+        });
+        ranked.into_iter().map(|hc| hc.cert.clone()).collect()
+    }
+
    /// Standalone keydb accessor: the disc's Volume ID (the keydb `I` token),
    /// looked up by the same disc-hash form [`Self::find_disc`] accepts. Pure
    /// file lookup; no crypto/derivation.
@@ -529,9 +534,6 @@ impl KeyDb {
    /// line per disc entry (sorted by hash). `parse(to_keydb_cfg(kd))` reproduces
    /// every field (see `round_trips_through_parse`). Used by the key-import tool
    /// to export a complete keydb.cfg (keys + host certs + VIDs).
-    ///
-    /// See docs/keydb-format.md for why the trailing `; <comment>` is only
-    /// emitted after a `U` (unit-keys) field.
    pub fn to_keydb_cfg(&self) -> String {
        fn hx(b: &[u8]) -> String {
            use std::fmt::Write;
@@ -784,7 +786,6 @@ impl KeyDb {
        let is_uhd = comment.contains("(UHD)");

        // Title kept VERBATIM (trimmed), a faithful copy for exact round-trip.
-        // See docs/keydb-format.md — why display prettification does NOT belong here.
        let before_fields = rest.split(" | ").next().unwrap_or("");
        // A title-only entry (no key fields) carries its `;` comment on the same
        // chunk — strip it so the comment doesn't leak into the title.
@@ -968,9 +969,8 @@ mod tests {
        assert_eq!(b.host_certs[0].revoked_at_mkb, Some(72));
    }

-    // REAL-DATA IDEMPOTENCE: parse → serialize (S1) → parse → serialize (S2);
-    // S1 must equal S2 byte-for-byte. REQUIRES a real keydb (KEYDB_PATH env);
-    // `#[ignore]` by default. See docs/keydb-format.md.
+    // REAL-DATA IDEMPOTENCE: parse → serialize (S1) → parse → serialize (S2); S1 must equal S2
+    // byte-for-byte. REQUIRES a real keydb (KEYDB_PATH env); `#[ignore]` by default.
    #[test]
    #[ignore = "needs a real keydb.cfg: KEYDB_PATH=<path> cargo test -- --ignored"]
    fn to_keydb_cfg_is_idempotent_on_real_keydb() {
@@ -1028,8 +1028,6 @@ mod tests {
    }

    // The real keydb for the `#[ignore]`d real-scale tests, or a LOUD failure.
-    // See docs/keydb-format.md — why silent `return` on a missing fixture is
-    // wrong here.
    fn real_keydb_path() -> std::path::PathBuf {
        keydb_path().expect(
            "KEYDB_PATH must point at a real keydb.cfg; run: \
@@ -1234,9 +1232,8 @@ mod tests {
        );
    }

-    // `load_counted` must read the HANDLE it was given, never re-resolve the
-    // path (identity stamp + bytes must match). See docs/keydb-format.md.
-    // With the path already replaced, the handle's contents must still win.
+    // `load_counted` must read the HANDLE it was given, never re-resolve the path (identity
+    // stamp + bytes must match).
    #[cfg(unix)]
    #[test]
    fn load_counted_reads_the_handle_not_the_path() {
@@ -1367,9 +1364,9 @@ mod tests {
        );
    }

-    // The SIBLING type: `KeyDb`'s hand-written `Debug` protects the whole-db
-    // rendering only; `{:?}` on one `KeydbHostCert` element walks a different
-    // path carrying the AACS host PRIVATE key. See docs/keydb-format.md.
+    // The SIBLING type: `KeyDb`'s hand-written `Debug` protects the whole-db rendering only;
+    // `{:?}` on one `KeydbHostCert` element walks a different path carrying the AACS host
+    // PRIVATE key.
    #[test]
    fn host_cert_debug_is_redacted_including_the_sibling_wrapper() {
        let hc = KeydbHostCert {
@@ -1930,6 +1927,7 @@ mod tests {
    // ── Host-cert revocation: parse + host_certs(mkb) filter ────────────────

    #[test]
+    #[allow(deprecated)]
    fn host_cert_revoked_parses_and_filters_by_mkb() {
        let revoked_line = format!(
            "| HC | HOST_PRIV_KEY 0x{} | HOST_CERT 0x{} ; Revoked in MKBv72",
@@ -1959,6 +1957,7 @@ mod tests {
    }

    #[test]
+    #[allow(deprecated)]
    fn host_cert_without_revocation_included_for_all_mkb() {
        let line = format!(
            "| HC | HOST_PRIV_KEY 0x{} | HOST_CERT 0x{}",
@@ -1975,6 +1974,7 @@ mod tests {
    }

    #[test]
+    #[allow(deprecated)]
    fn hc2_revocation_propagates_when_hc_has_none() {
        // The HC line carries no annotation; the revocation lives on the HC2
        // line. The combined cert must still be filtered by that generation
@@ -2195,6 +2195,7 @@ mod tests {
    /// so the returned SET is identified exactly, not merely counted. A cert
    /// revoked at generation R is usable iff the disc's generation is `< R`.
    #[test]
+    #[allow(deprecated)]
    fn host_certs_filters_several_certs_across_mkb_generations() {
        let hc = |marker: u8, note: &str| {
            format!(
@@ -2336,8 +2337,8 @@ mod tests {
        );
    }

-    // KEYDB-parser integration tests relocated from libfreemkv; exercise the
-    // parser end-to-end against a real keydb.cfg. See docs/keydb-format.md.
+    // KEYDB-parser integration tests relocated from libfreemkv; exercise the parser end-to-end
+    // against a real keydb.cfg.

    /// REQUIRES a real keydb; `#[ignore]` by default. Run with:
    /// `KEYDB_PATH=/path/to/keydb.cfg cargo test --release -- --ignored`.
@@ -2422,7 +2423,7 @@ mod tests {
        for entry in &candidate_entries {
            for (_, key) in &entry.unit_keys {
                let mut unit = original.clone();
-                libfreemkv::aacs::content::decrypt_unit(&mut unit, key);
+                libfreemkv::test_util::decrypt_unit(&mut unit, key);
                attempts += 1;
                any_key_changed_the_unit |= unit != original;
                if libfreemkv::aacs::content::is_clean(&unit, libfreemkv::disc::ContentFormat::BdTs)
@@ -2437,8 +2438,6 @@ mod tests {
        }

        // Reaching here is the EXPECTED outcome for this AACS 2.0 (BEE) sample.
-        // See docs/keydb-format.md for why "no key worked" alone would be an
-        // unusable assertion, and what is asserted instead.
        assert!(attempts > 0, "no unit key was tried at all");
        assert!(
            any_key_changed_the_unit,
@@ -1,11 +1,10 @@
 //! Pluggable AACS key sources for libfreemkv.
 //!
-//! libfreemkv owns the AACS crypto; this crate provides [`KeySource`] impls
-//! that look a disc up and drive the boil-down primitives to terminal Unit
-//! Keys: [`KeydbSource`] (local `keydb.cfg`) and [`OnlineSource`] (remote key
-//! service). Applications choose and order sources, then resolve and hand
-//! the key to `Disc::decrypt_with`; compose several with [`MultiSource`].
-//! See docs/lib-scope.md for the mechanism-vs-policy split with libfreemkv.
+//! libfreemkv owns the AACS crypto; this crate provides [`KeySource`] impls that look a disc up
+//! and drive the boil-down primitives to terminal Unit Keys: [`KeydbSource`] (local
+//! `keydb.cfg`) and [`OnlineSource`] (remote key service). Applications choose and order
+//! sources, then resolve and hand the key to `Disc::decrypt_with`; compose several with
+//! [`MultiSource`].

 mod keydb;
 /// The `keydb.cfg` parser (`KeyDb`, `DiscEntry`, …). Public: parsing the keydb
@@ -17,8 +16,11 @@ mod paths;

 pub use keydb::{KeydbSource, UpdateResult};
 pub use keydb_format::{DiscEntry, KeyDb};
+#[cfg(feature = "test-hooks")]
+pub use online::set_last_decode_reachability;
 pub use online::{
-    DecodeReachability, MIN_SAMPLE_UNITS, OnlineSource, take_last_decode_reachability,
+    DecodeReachability, KeyserverUrlFault, KeyserverUrlRejection, MIN_SAMPLE_UNITS, OnlineSource,
+    check_keyserver_url, check_keyserver_url_static, take_last_decode_reachability,
    validate_keyserver_url,
 };
 pub use paths::{default_keydb_path, existing_keydb_path, keydb_search_paths};
@@ -42,13 +44,11 @@ pub(crate) fn uks_from_vuk(vuk: &[u8; 16], enc_title_keys: &[[u8; 16]]) -> Vec<U

 /// An ordered composition of key sources, driven as one.
 ///
-/// [`MultiSource::get_unit_keys`] tries each inner source in order and
-/// returns the first non-empty Unit Key set (and
-/// [`MultiSource::get_fmts_indexes`] does the same for the forensic set). The
-/// caller supplies the list AND the order — local-first `[Keydb, Online]`,
-/// online-first `[Online, Keydb]`, etc. `MultiSource` is itself a
-/// [`KeySource`], so it nests and composes. See docs/lib-scope.md for the
-/// `Err`-vs-`Ok(empty)` failure contract.
+/// [`MultiSource::get_unit_keys`] tries each inner source in order and returns the first
+/// non-empty Unit Key set (and [`MultiSource::get_fmts_indexes`] does the same for the forensic
+/// set). The caller supplies the list AND the order — local-first `[Keydb, Online]`,
+/// online-first `[Online, Keydb]`, etc. `MultiSource` is itself a [`KeySource`], so it nests
+/// and composes.
 pub struct MultiSource {
    sources: Vec<Box<dyn KeySource>>,
 }
@@ -60,9 +60,9 @@ impl MultiSource {
    }
 }

-// Drive `sources` in order, returning the first non-empty result and
-// preserving Ok/Err when nothing resolves. `get` selects the trait method so
-// the base and forensic paths share one implementation. See docs/lib-scope.md.
+// Drive `sources` in order, returning the first non-empty result and preserving Ok/Err when
+// nothing resolves. `get` selects the trait method so the base and forensic paths share one
+// implementation.
 fn first_non_empty(
    sources: &[Box<dyn KeySource>],
    get: impl Fn(&dyn KeySource, &dyn ResolveCtx) -> Result<Vec<UnitKey>, libfreemkv::Error>,
@@ -137,9 +137,9 @@ impl KeySource for MultiSource {
        first_non_empty(&self.sources, |s, c| s.get_fmts_indexes(c), ctx)
    }

-    /// UNION every inner source's host certs (filtered at the given MKB
-    /// generation). Without this a composed source would hide an inner source's
-    /// cert from the OEM cert-auth route — the gap this fixes.
+    /// UNION every inner source's host certs, in source order (`mkb` is passed
+    /// through unchanged). Without this a composed source would hide an inner
+    /// source's cert from the OEM cert-auth route — the gap this fixes.
    fn host_certs(&self, mkb: Option<u32>) -> Vec<libfreemkv::aacs::types::HostCert> {
        self.sources
            .iter()
@@ -150,6 +150,23 @@ impl KeySource for MultiSource {
    fn label(&self) -> &'static str {
        "multi"
    }
+
+    // KU3-6: depends on samples if ANY inner source does, so a nested
+    // sample-dependent source keeps getting the per-piece ask.
+    fn answer_depends_on_samples(&self) -> bool {
+        self.sources.iter().any(|s| s.answer_depends_on_samples())
+    }
+
+    // Same `any(inner)` rule (KU-K1 review): `resolve` retries the composition
+    // whenever any inner source's last failure was transport-class.
+    fn last_failure_was_transport(&self) -> bool {
+        self.sources.iter().any(|s| s.last_failure_was_transport())
+    }
+
+    // KU J23: any inner source that consumes the VID makes the composition one.
+    fn uses_vid(&self) -> bool {
+        self.sources.iter().any(|s| s.uses_vid())
+    }
 }

 #[cfg(test)]
@@ -215,6 +232,92 @@ mod tests {
        assert!(multi.host_certs(None).is_empty());
    }

+    // A source whose `answer_depends_on_samples` is fixed to the given value —
+    // the only behaviour KSK2 exercises.
+    struct FixedDependency(bool);
+    impl KeySource for FixedDependency {
+        fn get_unit_keys(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, libfreemkv::Error> {
+            Ok(Vec::new())
+        }
+        fn answer_depends_on_samples(&self) -> bool {
+            self.0
+        }
+    }
+
+    // KSK2: `MultiSource::answer_depends_on_samples` is `any(inner)`, so nesting
+    // a sample-dependent online source under a sample-independent keydb still
+    // gets the per-piece ask (`resolve` must not treat the pair as keydb-only).
+    #[test]
+    fn multi_source_answer_depends_on_samples_is_any_inner() {
+        let all_independent = MultiSource::new(vec![
+            Box::new(FixedDependency(false)) as Box<dyn KeySource>,
+            Box::new(FixedDependency(false)) as Box<dyn KeySource>,
+        ]);
+        assert!(!all_independent.answer_depends_on_samples());
+
+        let keydb_then_online = MultiSource::new(vec![
+            Box::new(FixedDependency(false)) as Box<dyn KeySource>,
+            Box::new(FixedDependency(true)) as Box<dyn KeySource>,
+        ]);
+        assert!(keydb_then_online.answer_depends_on_samples());
+    }
+
+    // A source whose `uses_vid` is fixed to the given value.
+    struct FixedVid(bool);
+    impl KeySource for FixedVid {
+        fn get_unit_keys(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, libfreemkv::Error> {
+            Ok(Vec::new())
+        }
+        fn uses_vid(&self) -> bool {
+            self.0
+        }
+    }
+
+    // KU J23: like `answer_depends_on_samples`, a composed source uses the VID if any
+    // inner one does, so a nested online source still makes a Missing piece VID-derivable.
+    #[test]
+    fn multi_source_uses_vid_is_any_inner() {
+        let neither = MultiSource::new(vec![
+            Box::new(FixedVid(false)) as Box<dyn KeySource>,
+            Box::new(FixedVid(false)) as Box<dyn KeySource>,
+        ]);
+        assert!(!neither.uses_vid());
+        let keydb_then_online = MultiSource::new(vec![
+            Box::new(FixedVid(false)) as Box<dyn KeySource>,
+            Box::new(FixedVid(true)) as Box<dyn KeySource>,
+        ]);
+        assert!(keydb_then_online.uses_vid());
+    }
+
+    // A source whose `last_failure_was_transport` is fixed to the given value.
+    struct FixedTransport(bool);
+    impl KeySource for FixedTransport {
+        fn get_unit_keys(&self, _ctx: &dyn ResolveCtx) -> Result<Vec<UnitKey>, libfreemkv::Error> {
+            Ok(Vec::new())
+        }
+        fn last_failure_was_transport(&self) -> bool {
+            self.0
+        }
+    }
+
+    // For consistency with `answer_depends_on_samples` (KU3-6): a composed
+    // source's last-failure verdict is `any(inner)` too, so `resolve` retries
+    // the composition whenever ANY inner source's last failure was transport.
+    #[test]
+    fn multi_source_last_failure_was_transport_is_any_inner() {
+        let none_transport = MultiSource::new(vec![
+            Box::new(FixedTransport(false)) as Box<dyn KeySource>,
+            Box::new(FixedTransport(false)) as Box<dyn KeySource>,
+        ]);
+        assert!(!none_transport.last_failure_was_transport());
+
+        let one_transport = MultiSource::new(vec![
+            Box::new(FixedTransport(false)) as Box<dyn KeySource>,
+            Box::new(FixedTransport(true)) as Box<dyn KeySource>,
+        ]);
+        assert!(one_transport.last_failure_was_transport());
+    }
+
    /// The `mkb` generation must reach each inner source so its OWN revocation
    /// filter can act; a source that drops everything at a given generation is
    /// honoured by the union.
@@ -4,9 +4,8 @@
 //! just reads a handed-in path. This module gives the *search* list (first
 //! existing wins) and the single *default* write location.
 //!
-//! freemkv is portable: `keydb.cfg` lives next to the exe —
-//! `<dir of current exe>/keydb.cfg` — with no OS config-dir fallback.
-//! `--keydb PATH` bypasses this module. See docs/paths.md for rationale.
+//! freemkv is portable: `keydb.cfg` lives next to the exe — `<dir of current exe>/keydb.cfg` —
+//! with no OS config-dir fallback. `--keydb PATH` bypasses this module.

 use std::path::PathBuf;

@@ -138,7 +138,7 @@ fn keydb_source_label_is_keydb() {
    assert_eq!(KeydbSource::new("/nonexistent/keydb.cfg").label(), "keydb");
 }

-// ── KeydbSource: MKB-aware host-cert serving from a file ────────────────────
+// ── KeydbSource: host-cert serving from a file ──────────────────────────────

 #[test]
 fn keydb_source_serves_host_cert_from_hc_row() {
@@ -152,14 +152,13 @@ fn keydb_source_serves_host_cert_from_hc_row() {
    let path = s.write("keydb.cfg", &line);

    let src = KeydbSource::new(&path);
-    // Inherent (no-MKB, scan-options) form.
+    // Inherent (scan-options) form.
    assert_eq!(
        src.host_certs().len(),
        1,
        "inherent host_certs sees the HC row"
    );
-    // Trait form now wires the MKB generation through (no revocation annotation
-    // → always returned).
+    // Trait form: `mkb` is ignored; the ranked list is returned.
    let via_trait = KeySource::host_certs(&src, Some(70));
    assert_eq!(via_trait.len(), 1, "trait host_certs sees the HC row");
    assert_eq!(via_trait[0].certificate.len(), 92);
@@ -229,13 +228,14 @@ fn online_source_metadata() {
 }

 #[test]
-fn validate_keyserver_url_gates_scheme_and_ssrf() {
+fn validate_keyserver_url_gates_scheme_and_allows_lan() {
    assert!(validate_keyserver_url("https://8.8.8.8/keys").is_ok());
+    // Home app: LAN/loopback/link-local hosts pass; cleartext http and invalid addresses do not.
+    assert!(validate_keyserver_url("https://127.0.0.1/keys").is_ok());
+    assert!(validate_keyserver_url("https://169.254.1.5/keys").is_ok());
+    assert!(validate_keyserver_url("https://[::1]:9000/keys").is_ok());
    assert!(validate_keyserver_url("http://127.0.0.1/keys").is_err());
-    // SSRF blocking is IP-based, not scheme-gated: https://<private-IP> is rejected too.
-    assert!(validate_keyserver_url("https://127.0.0.1/keys").is_err());
-    assert!(validate_keyserver_url("http://169.254.169.254/latest/meta-data/").is_err());
-    assert!(validate_keyserver_url("http://[::1]:9000/keys").is_err());
+    assert!(validate_keyserver_url("https://0.0.0.0/keys").is_err());
    assert!(validate_keyserver_url("ftp://example.com/keys").is_err());
    assert!(validate_keyserver_url("").is_err());
 }
@@ -368,9 +368,7 @@ fn multi_source_real_keydb_resolves_through_chain() {
    );
 }

-// ── MultiSource: a source that could not ANSWER is not a source that said no ─
-// See docs/multi-source-failure-collapse.md — the Ok/Err collapse incident
-// this section's tests exist to catch.
+// ── MultiSource: a source that could not ANSWER is not a source that said no ─.

 /// A source that always fails, with a chosen error — the key-service outage.
 struct FailingSource {
@@ -398,8 +396,6 @@ fn unauthorized() -> libfreemkv::Error {
    libfreemkv::Error::KeyServiceUnauthorized
 }

-// See docs/multi-source-failure-collapse.md — must report FAILURE, not a
-// clean "no key", when no source holds a key and one could not answer.
 #[test]
 fn multi_source_reports_a_source_failure_instead_of_a_clean_no_key() {
    let multi = MultiSource::new(vec![
Author	SHA1	Message	Date
Matthew Jackson	940bb215ab	online: follow libfreemkv's halt::Progress rename to Liveness	2026-09-30 20:36:55 -07:00
Matthew Jackson	18b590407c	Cargo.lock: restore (accidentally changed by local patch)	2026-09-30 20:24:57 -07:00
Matthew Jackson	116b33739b	tests: halt-landing tests assert Halted, not a tight wall-clock bound	2026-09-30 20:24:46 -07:00
Matthew Jackson	d935fa6ffd	online: allow LAN/loopback/link-local key-service hosts, reuse libfreemkv is_blocked_ip	2026-09-30 20:03:38 -07:00
Matthew Jackson	b65959d3a1	ci: run cargo-deny from the repo dir so the .cargo patches apply	2026-09-30 16:09:03 -07:00
Matthew Jackson	3f08e980a0	ci: path-patch freemkv-unlock; dependabot ignores org workflow refs libfreemkv now deps freemkv-unlock by version with a git-tag override, so every root that reaches it patches it. Dependabot config unified; it no longer proposes freemkv/.github v1->v2.	2026-09-30 15:53:05 -07:00
Matthew Jackson	6c8e2c5c46	Allow forensic phase fallback after definitive key service misses	2026-09-29 17:20:43 -07:00
Matthew Jackson	ba357e46f5	online: wire ctx.halt()/ctx.progress() into the query worker (ST-K1b)	2026-09-28 08:18:38 -07:00
Matthew Jackson	a815a0a578	online: ST-K1b tests for ctx.halt()/ctx.progress() wiring (RED)	2026-09-28 08:15:20 -07:00
Matthew Jackson	ba6f213be3	KU-E1b: the key-service query is not yet Stop-aware (wording) check_keyserver_url_static's rustdoc and its test comment no longer call the first query halt-aware: OnlineSource runs it under its own Halt until ST-K1b wires ctx.halt() (J10).	2026-09-28 07:18:27 -07:00
Matthew Jackson	37568b1002	test: use the RFC 2606 .test TLD for the unresolvable host (leak-guard flags .invalid)	2026-09-28 07:04:48 -07:00
Matthew Jackson	40389acd3f	KU-E1 review minor 4: partial stored keys plus a Km still report NoVid The keydb keeps a NoVid miss reason beside the keys it did return, so resolve sets vid_would_help for the CPS units only the VID could derive. Other miss reasons are still reported only with no key.	2026-09-28 06:28:54 -07:00
Matthew Jackson	54508d8ec2	KU-E1 review minor 4 red: partial stored keys plus a Km still report NoVid A keydb entry with stored unit keys for some CPS units and a Media Key but no VID returns the stored keys with an empty miss path, so resolve cannot tell that the VID would derive the rest (J23).	2026-09-28 06:28:47 -07:00
Matthew Jackson	2c93420970	KU-E1: a DNS-free key-service URL check for factory builds check_keyserver_url_static rejects every Config fault (scheme, host, port, a literal non-public address) with no lookup. A factory build, which no Stop can reach, uses it; the host lookup and its SSRF guard run at the first query on the halt-aware worker, as they already did. A test-only counter proves the check starts no lookup.	2026-09-28 06:24:52 -07:00
Matthew Jackson	c48faa042b	KU-E1 red: a DNS-free key-service URL check for factory builds The engine checks the key-service URL, a DNS lookup with a fixed 10 s timeout that Stop cannot interrupt, on every factory build, and no Halt reaches a factory. The test asks for a static check that rejects Config faults with no lookup.	2026-09-28 05:45:58 -07:00
Matthew Jackson	ab93818012	KU-E1 J23: OnlineSource and MultiSource report uses_vid OnlineSource::uses_vid is true (it sends vid_b64); MultiSource is any(inner); KeydbSource keeps the default false.	2026-09-28 05:31:51 -07:00
Matthew Jackson	f3b66307cc	KU-E1 J23 red: which key sources consume the disc's VID OnlineSource sends the VID (vid_b64), so it uses it; MultiSource uses it if any inner source does; KeydbSource does not (its Km-without-VID case is reported per disc, as a NoVid miss path).	2026-09-28 05:31:23 -07:00
Matthew Jackson	ad59f3ce45	KU-K1 review: peek the reachability slot, MultiSource forwards last_failure record_last_failure_transport now reads LAST_DECODE_REACHABILITY.with(\|c\| c.get()) directly instead of take_last_decode_reachability(), so it no longer erases the slot freemkv-library's server reads after resolve (server/ripper/mod.rs:505, :1361) to avoid a second key-service call. Green: the regression test now finds the verdict still in the slot after get_unit_keys/get_fmts_indexes. MultiSource::last_failure_was_transport forwards any(inner), matching answer_depends_on_samples (KU3-6).	2026-09-28 04:19:04 -07:00
Matthew Jackson	4e83b3c1f8	KU-K1 review: red — record_last_failure_transport erases the reachability slot Opus's review: freemkv-library's server calls take_online_decode_reachability() after resolve (server/ripper/mod.rs:505, :1361) to classify a no-key without a second probe. record_last_failure_transport currently TAKES the thread-local slot, so the server sees None and fires probe_online_reachability — a second key-service call, and a definite 422 misread as an outage. Red: the slot is gone after get_unit_keys/get_fmts_indexes. Also adds the forensic-path, mid-body-stall, transport-then-5xx-reset and MultiSource forwarding tests requested in review; the latter fails since MultiSource has no override yet.	2026-09-28 04:18:02 -07:00
Matthew Jackson	c5985d1c87	KU-K1: keydb/multi sample-dependence and online transport-class failures Per keys-upfront-design KU-K1 (§8.2): KeydbSource::answer_depends_on_samples is false (keyed by disc hash, asked once per resolve, N-KU10); MultiSource's is any(inner) (KU3-6), so a nested sample-dependent source still gets the per-piece ask. OnlineSource::last_failure_was_transport (J15) is true only when the most recent query recorded DecodeReachability::Transport (DNS, connect refused, or an idle stall — never an HTTP answer, 5xx included), and resets on the next success, so resolve's J13 retry (stop-design-v5 T31) targets exactly the requests that never got an answer.	2026-09-28 04:13:03 -07:00
Matthew Jackson	8f923fd5f9	KU-K1: tests for answer_depends_on_samples and last_failure_was_transport KeydbSource::answer_depends_on_samples (KSK1) and MultiSource::answer_depends_on_samples (KSK2, KU3-6 "any(inner)") both default to `true` today, so a keydb-then-online composition would be re-asked per piece instead of once. OnlineSource::last_failure_was_transport (J15) defaults to `false`, so a transient DNS/connect/idle failure would never be retried by `resolve` (J13). Red: these six assertions fail against today's defaults.	2026-09-28 04:12:12 -07:00
Matthew Jackson	18fdab6b77	KU-P1: decrypt the real-unit test through test_util::decrypt_unit aacs::content::decrypt_unit becomes pub(crate) at KU-X2 (keys-upfront design v3.4 §2.2); the ignored real-unit test now uses the test-util door. The feature comes in as a dev-dependency (resolved through the sibling path patch).	2026-09-28 00:22:08 -07:00
Matthew Jackson	dfa02adbe2	online: a stopped key query never sends and builds no body Review fixes, green half: - PostJob carries the caller's Halt and re-checks it after the host lookup, before connecting. A Stop during DNS then never uploads the key material or bearer token, so a reopen's query is the only one the service sees. - query_with returns Halted before reading or base64-encoding the MKB when a Stop is already pending.	2026-09-27 23:50:33 -07:00
Matthew Jackson	cbab284c85	online: tests that a stopped key query sends nothing and reads no disc material Review fixes, red half: a Stop during the host lookup must never reach the service (never call the key service twice), and a pending Stop returns before the body is built. KT7a's u64::MAX check now asserts saturation.	2026-09-27 23:49:08 -07:00
Matthew Jackson	0ffdb2a9f6	online: stall-only key-service timeouts and mid-flight Stop (ST-K1a) Commit 2 of 2 (stop-design-v5 §2.7, T15-T17, D3, D4): - query_with builds the body on the caller's thread and runs DNS + POST on a worker, capped at 4 per host. The caller waits for a slot and for the result halt-aware in 20 ms slices, so Stop returns Halted within a slice at any stage. The abandoned worker frees its slot at its own stall bound. - Reachability is recorded on the caller's thread, only when the worker's result arrives. A Stop records nothing. - IdleConnector, chained after DefaultConnector, owns every post-connect bound. Each write and read gets a fresh 60 s stall bound (T16), and the wait for a reply's first byte gets 60 s + request bytes / 256 KiB/s (T17). The 180 s phase totals are gone: no total is configured. - A reply body that stalls or drops records Transport reachability (T16). An over-cap body still records its Status. The trait path passes a fresh Halt. ctx.halt()/ctx.progress() is ST-K1b, after KU-X2. No public API change.	2026-09-27 23:41:43 -07:00
Matthew Jackson	adbb1a12a0	online: ST-K1a tests for stall-only key-service timeouts and mid-flight Stop Commit 1 of 2 (stop-design-v5 §5.0): KT1-KT10 plus guards G12/G13, with signatures that keep today's behaviour (query_with ignores the halt, hardened_agent_with maps idle onto the old phase totals, the first-byte budget does not scale), so each test compiles and fails on its assertion. KT9 replaces the 180 s totals test. The ctx.halt()/ctx.progress() wiring is ST-K1b (after KU-X2).	2026-09-27 23:37:22 -07:00
Matthew Jackson	05281249d1	keydb: hand out host certs best first, with no disc input Unannotated certs in keydb order, then revoked ones by latest revocation. The trait ignores its mkb hint; KeyDb::host_certs(mkb) is deprecated.	2026-09-27 17:24:04 -07:00
Matthew Jackson	cedbc4b1fa	online: offline Temporary-verdict test; proxy wording Drop the real-DNS .invalid test for an offline check of every GuardFail::Unreachable reason; say every key lookup failed.	2026-09-27 16:44:34 -07:00
Matthew Jackson	1606ff3ca3	online: review nits for the proxy fix and keyserver URL verdict Correct the rationale: the env proxy was resolved to the key service's pinned address, so every lookup failed. Gate set_last_decode_reachability behind a test-hooks feature, mark the verdict types non_exhaustive, test a .invalid host, add CHANGELOG.	2026-09-27 12:40:09 -07:00
Matthew Jackson	10b0348db8	online: never use an env proxy; typed keyserver URL verdict and reachability test hook The key-service agent disables ureq's env proxy, which would re-resolve the host and bypass the pinned, SSRF-guarded addresses. check_keyserver_url returns a Permanent/Temporary KeyserverUrlRejection; set_last_decode_reachability plants a verdict for caller tests.	2026-09-27 12:26:39 -07:00
Matthew Jackson	d0a3ab852b	v1.7.7: bump version (unified release)	2026-09-26 21:16:59 +00:00
Matthew Jackson	91b906fa61	Prepare 1.7.7 with concise comments and shared CI policy	2026-09-26 11:46:35 -07:00
Matthew Jackson	e987506d96	v1.7.6: bump version (unified release)	2026-09-26 04:05:43 +00:00
Matthew Jackson	60cff0ead6	chore: absorb qa into dev for lockstep promote [skip-media]	2026-09-25 12:25:47 -07:00