v1.4.3: bump version (unified release)

The key service now always returns {"UK":[...]} - an array of one for a
plain movie sample, or all 32 index-ordered variant keys for a forensic
sample. OnlineSource::query accepts both the legacy string form and the
array form, emitting one UnitKey per element (index = array position).
Re-export MIN_SAMPLE_UNITS so callers size their samples correctly.

CHANGELOG.md

@@ -1,5 +1,62 @@
 # Changelog
 
+## [1.4.2] — 2026-07-15
+
+Version sync with the workspace; inherits libfreemkv 1.4.2. The keydb test that
+feeds real key material into the AACS crypto was adapted to the segregated
+`decrypt_unit` + `is_clean` primitives (behaviour unchanged).
+
+## [1.4.1] — 2026-07-14
+
+Version sync with the workspace; inherits libfreemkv 1.4.1.
+
+## [1.4.0] — 2026-07-13
+
+Version sync with the workspace; inherits libfreemkv 1.4.0.
+
+## [1.3.2] — 2026-07-10
+
+### Changed
+
+- Unit keys carry libfreemkv's new `UnitKey.variant_number`; every source
+  (keydb, online, VUK-derived) emits `0` — ordinary, non-forensic content —
+  via the `UnitKey::new` constructor. No behaviour change. Inherits
+  **libfreemkv 1.3.2**.
+
+## [1.3.1] — 2026-07-10
+
+### Licensing
+
+- **Relicensed to the MIT License, from 1.3.1 onwards** (releases up to and
+  including 1.3.0 remain under AGPL-3.0).
+
+Version sync with the workspace; inherits libfreemkv 1.3.1.
+
+## [1.3.0] — 2026-07-08
+
+### Added
+
+- **AACS 2.0 host certs round-trip through `keydb.cfg`.** `to_keydb_cfg` now
+  emits the sibling `| HC2 |` line — the inverse of the v2 host-cert parser — so
+  writing a keydb back out no longer silently drops AACS 2.0 host certs.
+
+### Changed
+
+- **Resolve runs directly on `libfreemkv::aacs` primitives.** After libfreemkv
+  dropped its `aacs::boil` veneer, the resolve path now calls
+  `derive_media_key_from_{pk,dk}`, `derive_vuk`, and `decrypt_unit_key` from
+  `aacs::derive` with the `aacs::types` newtypes. No behaviour change.
+- Inherits **libfreemkv 1.3.0**.
+
+### Fixed
+
+- **keydb save-validation matches the parser exactly.** A `0x` line counts as a
+  disc entry only when it also contains ` = `, so validating and persisting
+  content that parses to zero usable entries (e.g. a stray `0xDEADBEEF` line) can
+  no longer succeed.
+- **Disc-entry titles round-trip verbatim** (parentheses and all) — the parse
+  path now keeps the title exactly as the emit path writes it.
+
 ## [1.2.0] — 2026-06-29
 
 ### Changed

Cargo.toml

@@ -1,9 +1,9 @@
 [package]
 name = "freemkv-keysources"
-version = "1.2.0"
+version = "1.4.3"
 edition = "2024"
 rust-version = "1.86"
-license = "AGPL-3.0-only"
+license = "MIT"
 description = "Pluggable AACS key sources (keydb, online key service) for libfreemkv. Each source looks a disc up and hands libfreemkv its terminal Unit Keys via get_uk; the library does all derivation."
 repository = "https://github.com/freemkv/freemkv-keysources"
 keywords = ["aacs", "blu-ray", "uhd", "decryption", "keydb"]
@@ -17,7 +17,7 @@ publish = false
 # The crate provides the `KeySource` trait + `Key`/`DiscInputs` types these impls fill.
 # libfreemkv is git-only now; the committed [patch.crates-io] below redirects this
 # bare version req to the libfreemkv git tag (local dev overrides it to a path).
-libfreemkv = "1.2"
+libfreemkv = "1.4"
 # OnlineSource: POST disc inputs + samples to a key service over HTTP.
 ureq = { version = "2", features = ["json"] }
 serde_json = "1"
@@ -40,4 +40,4 @@ 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 = "v1.2.0" }
+libfreemkv = { git = "https://github.com/freemkv/libfreemkv", tag = "v1.4.3" }

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Matthew Jackson & Contributors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

src/keydb.rs

@@ -1,20 +1,21 @@
 //! `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** itself by driving libfreemkv's boil-down
-//! primitives ([`uk_from_vuk`] / [`vuk_from_mk`] / [`mk_from_pk`] /
-//! [`mk_from_dk`]) — never re-implementing AES. The path it picks mirrors the
-//! OLD candidate order (which libfreemkv's resolver used to walk) EXACTLY,
-//! cheapest-first:
+//! disc's terminal **Unit Keys** itself by composing libfreemkv's raw
+//! `aacs::derive` primitives (`derive_vuk` / `decrypt_unit_key` /
+//! `derive_media_key_from_pk` / `derive_media_key_from_dk`) — never
+//! re-implementing AES. The path it picks mirrors the OLD candidate order
+//! (which libfreemkv's resolver used to walk) EXACTLY, cheapest-first:
 //!
 //! 1. per-disc **Unit Keys** (hash hit)  → returned terminal, no derivation.
-//! 2. per-disc **VUK** (hash hit)        → [`uk_from_vuk`] over the disc's
+//! 2. per-disc **VUK** (hash hit)        → `uks_from_vuk` over the disc's
 //!    encrypted title keys.
-//! 3. a **Media Key**, then [`vuk_from_mk`] → [`uk_from_vuk`]. The MK comes
+//! 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 [`mk_from_pk`];
-//!    or the device-key pool via [`mk_from_dk`]. The PK and DK pools resolve the
-//!    Media Key WITHOUT a VID; the final [`vuk_from_mk`] still needs one. The
+//!    **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
@@ -31,9 +32,9 @@
 use std::io::{Read, Write};
 use std::path::{Path, PathBuf};
 
-use libfreemkv::aacs::{
-    HostCert, MediaKey, UnitKey, Vid, Vuk, mk_from_dk, mk_from_pk, uk_from_vuk, vuk_from_mk,
-};
+use crate::uks_from_vuk;
+use libfreemkv::aacs::derive::{derive_media_key_from_dk, derive_media_key_from_pk, derive_vuk};
+use libfreemkv::aacs::types::{HostCert, MediaKey, UnitKey, Vid};
 use libfreemkv::keysource::ResolveCtx;
 use libfreemkv::{Error, KeySource};
 
@@ -89,7 +90,11 @@ impl KeydbSource {
             .lines()
             .filter(|l| {
                 let t = l.trim();
-                t.starts_with("0x")
+                // Mirror KeyDb::parse's disc-entry rule EXACTLY (keydb_format.rs:
+                // a "0x" line is only an entry if it also contains " = "), so
+                // save() never validates + persists content that parses to zero
+                // usable entries (e.g. a stray "0xDEADBEEF" comment line).
+                (t.starts_with("0x") && t.contains(" = "))
                     || t.starts_with("| DK")
                     || t.starts_with("| PK")
                     || t.starts_with("| HC")
@@ -179,10 +184,7 @@ impl KeydbSource {
         // 1. Terminal Unit Keys stored in the entry — directly usable, no
         //    derivation. Preserve the keydb's CPS numbering (idx = num - 1).
         for (num, key) in &entry.unit_keys {
-            keys.push(UnitKey {
-                idx: num.saturating_sub(1),
-                key: *key,
-            });
+            keys.push(UnitKey::new(num.saturating_sub(1), *key));
         }
 
         // The disc's encrypted title keys (from Unit_Key_RO.inf) — what every
@@ -199,17 +201,23 @@ impl KeydbSource {
             //       Either branch yields the COMPLETE declared set, so we take the
             //       first that resolves (VUK preferred — cheapest).
             let derived = if let Some(vuk) = entry.vuk {
-                uk_from_vuk(Vuk(vuk), enc_title_keys)
+                uks_from_vuk(&vuk, enc_title_keys)
             } else {
                 let vid = ctx.vid().or_else(|| entry.vid.map(Vid));
                 let mkb = ctx.mkb().unwrap_or(&[]);
                 let mk: Option<MediaKey> = entry
                     .media_key
                     .map(MediaKey)
-                    .or_else(|| mk_from_pk(&db.processing_keys, mkb).ok())
-                    .or_else(|| vid.and_then(|v| mk_from_dk(&db.device_keys, mkb, v).ok()));
+                    .or_else(|| derive_media_key_from_pk(mkb, &db.processing_keys).map(MediaKey))
+                    // DK pool: the real Subset-Difference MKB walk. No VID at the MK
+                    // step (it enters at the VUK step below); the VID guard follows.
+                    .or_else(|| derive_media_key_from_dk(mkb, &db.device_keys).map(MediaKey));
                 match (mk, vid) {
-                    (Some(mk), Some(vid)) => uk_from_vuk(vuk_from_mk(mk, vid), enc_title_keys),
+                    // VUK = derive_vuk(MK, VID), then boil the disc's encrypted
+                    // title keys to the terminal Unit Keys.
+                    (Some(mk), Some(vid)) => {
+                        uks_from_vuk(&derive_vuk(&mk.0, &vid.0), enc_title_keys)
+                    }
                     // Locked VID-per-path rule: an MK with no VID cannot derive.
                     _ => Vec::new(),
                 }
@@ -351,7 +359,8 @@ impl KeySource for KeydbSource {
 mod tests {
     use super::*;
     use crate::keydb_format::DiscEntry;
-    use libfreemkv::aacs::{DeviceKey, derive_vuk};
+    use libfreemkv::aacs::derive::derive_vuk;
+    use libfreemkv::aacs::types::DeviceKey;
     use std::collections::HashMap;
 
     // ── A test ResolveCtx, so get_uk's path selection can be exercised without
@@ -468,7 +477,7 @@ mod tests {
     fn union_partial_stored_plus_vuk_yields_all_declared_units() {
         let vuk = [0x5Au8; 16];
         let enc = vec![[0x31u8; 16], [0xCDu8; 16]]; // two declared CPS units
-        let derived = uk_from_vuk(Vuk(vuk), &enc); // [d0, d1]
+        let derived = crate::uks_from_vuk(&vuk, &enc); // [d0, d1]
 
         let mut e = blank_entry(HASH);
         e.unit_keys = vec![(1, [0xA0u8; 16])]; // PARTIAL: only uk1 stored
@@ -505,7 +514,7 @@ mod tests {
 
         let got = KeydbSource::unit_keys_from(&db, &ctx(HASH, enc.clone(), None));
         // Reference: the boil primitive directly — the OLD derivation.
-        let expect = uk_from_vuk(Vuk(vuk), &enc);
+        let expect = crate::uks_from_vuk(&vuk, &enc);
         assert_eq!(
             got, expect,
             "VUK path must equal uk_from_vuk(vuk, enc_title_keys)"
@@ -536,11 +545,11 @@ mod tests {
 
         let got = KeydbSource::unit_keys_from(&db, &ctx(HASH, enc.clone(), Some(Vid(vid_phys))));
         // Reference uses the PHYSICAL VID.
-        let expect = uk_from_vuk(vuk_from_mk(MediaKey(mk), Vid(vid_phys)), &enc);
+        let expect = crate::uks_from_vuk(&derive_vuk(&mk, &vid_phys), &enc);
         assert_eq!(got, expect, "MK path must use the physical (unlock) VID");
         // Sanity: it must NOT match the keydb-VID derivation (different VID →
         // different VUK → different keys), proving the right VID was selected.
-        let wrong = uk_from_vuk(vuk_from_mk(MediaKey(mk), Vid(vid_keydb)), &enc);
+        let wrong = crate::uks_from_vuk(&derive_vuk(&mk, &vid_keydb), &enc);
         assert_ne!(
             got, wrong,
             "must not derive with the keydb VID when a physical VID exists"
@@ -564,7 +573,7 @@ mod tests {
 
         // ctx.vid() == None → ISO path.
         let got = KeydbSource::unit_keys_from(&db, &ctx(HASH, enc.clone(), None));
-        let expect = uk_from_vuk(vuk_from_mk(MediaKey(mk), Vid(vid_keydb)), &enc);
+        let expect = crate::uks_from_vuk(&derive_vuk(&mk, &vid_keydb), &enc);
         assert_eq!(
             got, expect,
             "MK path must use the keydb VID when no physical VID is present"
@@ -665,7 +674,7 @@ mod tests {
         let got = KeydbSource::unit_keys_from(&db, &ctx);
         assert!(!got.is_empty(), "PK pool must yield Unit Keys for the disc");
         // Byte-identical to deriving from the recovered MK via the public chain.
-        let expect = uk_from_vuk(vuk_from_mk(MediaKey(mk), Vid(vid_phys)), &enc);
+        let expect = crate::uks_from_vuk(&derive_vuk(&mk, &vid_phys), &enc);
         assert_eq!(
             got, expect,
             "PK path must equal MK → VUK → UK from the recovered Media Key"
@@ -708,16 +717,6 @@ mod tests {
         );
     }
 
-    /// `vuk_from_mk` anchor: the VUK the MK path derives equals the library's own
-    /// `derive_vuk(mk, vid)` (the pre-boil primitive) — pinning that the boil
-    /// chain this source drives is the audited math, not a re-implementation.
-    #[test]
-    fn mk_path_vuk_matches_library_derive_vuk() {
-        let mk = [0x3Cu8; 16];
-        let vid = [0xA5u8; 16];
-        assert_eq!(vuk_from_mk(MediaKey(mk), Vid(vid)).0, derive_vuk(&mk, &vid));
-    }
-
     /// No per-disc entry → no key, even with a universal device-key pool present.
     /// Without a matched entry there is no per-disc anchor, so the global pools
     /// are never consulted (the cross-disc MK-pool brute stays retired).
@@ -816,7 +815,7 @@ mod tests {
         let target = dir.join("nested").join("mykeys.cfg");
         let src = KeydbSource::new(&target);
 
-        let body = b"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF\n";
+        let body = b"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF = Test\n";
         let result = src.save(body).expect("save must succeed");
 
         assert_eq!(
@@ -842,9 +841,9 @@ mod tests {
         let target = dir.join("k.cfg");
         let src = KeydbSource::new(&target);
 
-        let body = b"0xAABBCCDDAABBCCDDAABBCCDDAABBCCDD\n".to_vec();
+        let body = b"0xAABBCCDDAABBCCDDAABBCCDDAABBCCDD = Test\n".to_vec();
         let result = src
-            .update(|_url| Ok(body.clone()), "http://example.invalid/keydb.zip")
+            .update(|_url| Ok(body.clone()), "http://example.test/keydb.zip")
             .expect("update must succeed with a good fetch");
 
         assert_eq!(result.path, target, "update must save to the source's path");

src/keydb_format.rs

@@ -17,7 +17,7 @@
 
 use std::collections::HashMap;
 
-use libfreemkv::aacs::{DeviceKey, HostCert};
+use libfreemkv::aacs::types::{DeviceKey, HostCert};
 
 /// A keydb per-disc unit key: the CPS-unit number paired with its 16-byte key.
 pub type NumberedUnitKey = (u32, [u8; 16]);
@@ -390,6 +390,8 @@ impl KeyDb {
         let mut out = String::new();
 
         // Host certs (AACS 1.0): | HC | HOST_PRIV_KEY 0x.. | HOST_CERT 0x.. ; Revoked in MKBv<N>
+        // AACS 2.0 credentials ride a sibling `| HC2 |` line; emit it too so a
+        // round-trip through `to_keydb_cfg` never silently drops v2 host certs.
         for hc in &self.host_certs {
             out.push_str("| HC | HOST_PRIV_KEY 0x");
             out.push_str(&hx(&hc.cert.private_key));
@@ -400,6 +402,17 @@ impl KeyDb {
                 out.push_str(&n.to_string());
             }
             out.push('\n');
+            // AACS 2.0 (HC2): inverse of `parse_host_cert_v2`.
+            if let (Some(pk2), Some(cert2)) = (
+                hc.cert.private_key_v2.as_ref(),
+                hc.cert.certificate_v2.as_ref(),
+            ) {
+                out.push_str("| HC2 | HOST_PRIV_KEY 0x");
+                out.push_str(&hx(pk2));
+                out.push_str(" | HOST_CERT 0x");
+                out.push_str(&hx(cert2));
+                out.push('\n');
+            }
         }
 
         // Device keys: | DK | DEVICE_KEY 0x.. | DEVICE_NODE 0x.. | KEY_UV 0x.. | KEY_U_MASK_SHIFT 0x..
@@ -429,9 +442,8 @@ impl KeyDb {
             // `0x` would double it on re-parse).
             out.push_str(h);
             out.push_str(" = ");
-            // Parse stores the display title (inside parens) or the whole string
-            // when there are none; emitting the stored title bare round-trips
-            // (no parens → parser keeps it verbatim). Empty → "Unknown".
+            // Parse stores the title VERBATIM (parens and all), so emitting it
+            // bare round-trips through parse. Empty → "Unknown".
             if d.title.is_empty() {
                 out.push_str("Unknown");
             } else {
@@ -1096,8 +1108,8 @@ mod tests {
 
     #[test]
     fn disc_entry_malformed_parens_falls_back_to_whole_title() {
-        // ')' before '(' would make start+1 > end; the guarded get() returns
-        // None and the parser falls back to the whole title (no panic).
+        // The title is kept verbatim regardless of paren placement — a malformed
+        // ')' before '(' is not special-cased; the whole string is the title.
         let line = "0x00 = FILM) (X | M | 0x".to_string() + &"00".repeat(16);
         let e = KeyDb::parse_disc_entry(&line).unwrap();
         assert_eq!(e.title, "FILM) (X");
@@ -1400,7 +1412,7 @@ mod tests {
     //
     // 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 / decrypt_unit_try_keys). They live here now that the
+    // (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.
     // ════════════════════════════════════════════════════════════════════
@@ -1427,7 +1439,7 @@ mod tests {
         let vid = entry.vid.unwrap();
         let expected_vuk = entry.vuk.unwrap();
 
-        let derived = libfreemkv::aacs::derive_vuk(&mk, &vid);
+        let derived = libfreemkv::aacs::derive::derive_vuk(&mk, &vid);
         assert_eq!(
             derived, expected_vuk,
             "VUK derivation failed for disc: {} (hash {})",
@@ -1452,9 +1464,9 @@ mod tests {
         }
 
         let original = std::fs::read(&unit_path).unwrap();
-        assert_eq!(original.len(), libfreemkv::aacs::ALIGNED_UNIT_LEN);
+        assert_eq!(original.len(), libfreemkv::aacs::content::ALIGNED_UNIT_LEN);
         assert!(
-            libfreemkv::aacs::ts_sync_destroyed(&original),
+            !libfreemkv::aacs::content::is_clean(&original, libfreemkv::disc::ContentFormat::BdTs),
             "Unit should be encrypted"
         );
 
@@ -1473,20 +1485,20 @@ mod tests {
 
         eprintln!("Found {} entries with unit keys", candidate_entries.len());
 
-        // Try each entry's unit keys
+        // Try each entry's unit keys: apply the key, then ask whether it opened
+        // the unit (the segregated primitives — decrypt, then structural check).
         for entry in &candidate_entries {
-            let keys: Vec<[u8; 16]> = entry.unit_keys.iter().map(|(_, k)| *k).collect();
-            let mut unit = original.clone();
-
-            if let Some(res) = libfreemkv::aacs::decrypt_unit_try_keys(&mut unit, &keys) {
-                eprintln!(
-                    "SUCCESS: Decrypted with entry {} ({res:?})",
-                    entry.disc_hash
-                );
-                // Count TS sync bytes
-                let ts = (0..32).filter(|&i| unit[4 + i * 192] == 0x47).count();
-                eprintln!("  TS sync bytes: {}/32", ts);
-                return;
+            for (_, key) in &entry.unit_keys {
+                let mut unit = original.clone();
+                libfreemkv::aacs::content::decrypt_unit(&mut unit, key);
+                if libfreemkv::aacs::content::is_clean(&unit, libfreemkv::disc::ContentFormat::BdTs)
+                {
+                    eprintln!("SUCCESS: Decrypted with entry {}", entry.disc_hash);
+                    // Count TS sync bytes
+                    let ts = (0..32).filter(|&i| unit[4 + i * 192] == 0x47).count();
+                    eprintln!("  TS sync bytes: {}/32", ts);
+                    return;
+                }
             }
         }
 
@@ -1526,7 +1538,7 @@ mod tests {
 
         // Verify VUK derivation if we have MK + VID
         if let Some(mk) = entry.media_key {
-            let derived = libfreemkv::aacs::derive_vuk(&mk, &vid);
+            let derived = libfreemkv::aacs::derive::derive_vuk(&mk, &vid);
             assert_eq!(derived, vuk, "VUK derivation mismatch");
             eprintln!("VUK derivation verified");
         }

src/lib.rs

@@ -30,15 +30,27 @@ mod paths;
 
 pub use keydb::{KeydbSource, UpdateResult};
 pub use keydb_format::{DiscEntry, KeyDb};
-pub use online::{OnlineSource, validate_keyserver_url};
+pub use online::{MIN_SAMPLE_UNITS, OnlineSource, validate_keyserver_url};
 pub use paths::{default_keydb_path, existing_keydb_path, keydb_search_paths};
 
 // Re-exported for downstream convenience so apps need only depend on this crate
 // for the source-side types.
-pub use libfreemkv::aacs::UnitKey;
+pub use libfreemkv::aacs::types::UnitKey;
 pub use libfreemkv::keysource::ResolveCtx;
 pub use libfreemkv::{DiscInputs, KeySource};
 
+/// VUK → the disc's terminal Unit Keys (positional index), one AES-ECB-decrypt
+/// per encrypted title key. Composes the raw `aacs::derive::decrypt_unit_key`
+/// primitive directly — replaces the removed libfreemkv `aacs::boil::uk_from_vuk`
+/// wrapper (that veneer is gone; libfreemkv owns only the AES).
+pub(crate) fn uks_from_vuk(vuk: &[u8; 16], enc_title_keys: &[[u8; 16]]) -> Vec<UnitKey> {
+    enc_title_keys
+        .iter()
+        .enumerate()
+        .map(|(i, e)| UnitKey::new(i as u32, libfreemkv::aacs::derive::decrypt_unit_key(vuk, e)))
+        .collect()
+}
+
 /// An ordered composition of key sources, driven as one. [`MultiSource::get_uk`]
 /// tries each inner source in order and returns the first non-empty Unit Key
 /// set. **The caller supplies the list AND the order** — local-first `[Keydb,
@@ -76,7 +88,7 @@ impl KeySource for MultiSource {
     /// 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.
-    fn host_certs(&self, mkb: Option<u32>) -> Vec<libfreemkv::aacs::HostCert> {
+    fn host_certs(&self, mkb: Option<u32>) -> Vec<libfreemkv::aacs::types::HostCert> {
         self.sources
             .iter()
             .flat_map(|s| s.host_certs(mkb))

src/online.rs

@@ -4,8 +4,9 @@ use std::io::Read;
 use std::net::{IpAddr, SocketAddr, ToSocketAddrs};
 use std::time::Duration;
 
+use crate::uks_from_vuk;
 use base64::Engine;
-use libfreemkv::aacs::{UnitKey, Vuk, uk_from_vuk};
+use libfreemkv::aacs::types::UnitKey;
 use libfreemkv::keysource::ResolveCtx;
 use libfreemkv::{Error, KeySource};
 
@@ -15,6 +16,19 @@ use libfreemkv::{Error, KeySource};
 // record stream is normally a few MiB; this is headroom, not an expected size).
 const MAX_MKB_BYTES: usize = 64 * 1024 * 1024;
 const TIMEOUT_SECS: u64 = 180;
+/// Minimum encrypted-content samples the online source will send in one key
+/// request — re-exported from the base crate ([`libfreemkv::keysource::MIN_SAMPLE_UNITS`])
+/// so this crate and libfreemkv's own FMTS forensic query share ONE value.
+///
+/// The service identifies the key by which of the submitted units it decrypts,
+/// so too few samples — especially on FMTS, where a segment interleaves several
+/// variants at the unit level — can return a key that matches an incidental unit
+/// rather than the one asked about (a false positive). A request carrying fewer
+/// is refused (empty result → the resolver moves to the next source) rather than
+/// sent and trusted. Kept public so callers that GATHER the samples (the CLI,
+/// autorip) sample at least this many — sampling fewer guarantees the request is
+/// skipped and the online source never consulted.
+pub use libfreemkv::keysource::MIN_SAMPLE_UNITS;
 /// Hard cap on the key-service response body. A real unit-key reply is a few
 /// hundred bytes; bound the read so a malicious/compromised server can't drive
 /// the client to OOM with an unbounded body.
@@ -218,6 +232,22 @@ impl OnlineSource {
             );
             return Vec::new();
         }
+        // Gather encrypted-content samples FIRST and enforce the minimum: the
+        // service resolves a key by which submitted unit it decrypts, so a
+        // request carrying fewer than `MIN_SAMPLE_UNITS` can return a key matching
+        // an incidental unit (a false positive, seen on FMTS variant units). Refuse
+        // to send an under-sampled request — return empty so the resolver falls
+        // through to the next source rather than trusting an ambiguous key.
+        let samples = ctx.samples(64).unwrap_or_default();
+        if samples.len() < MIN_SAMPLE_UNITS {
+            tracing::info!(
+                target: "freemkv::keysource",
+                samples = samples.len(),
+                min = MIN_SAMPLE_UNITS,
+                "too few content samples for a reliable online key request; skipping the online source"
+            );
+            return Vec::new();
+        }
         let b64 = base64::engine::general_purpose::STANDARD;
         let mut body = serde_json::json!({
             // Raw Unit_Key_RO.inf, verbatim — the server does its own parse /
@@ -228,18 +258,14 @@ impl OnlineSource {
         if let Some(vid) = ctx.vid() {
             body["vid_b64"] = serde_json::Value::String(b64.encode(vid.0));
         }
-        // Up to a generous cap of encrypted content samples for server-side
-        // ciphertext validation.
-        if let Ok(samples) = ctx.samples(64) {
-            if !samples.is_empty() {
-                body["units_b64"] = serde_json::Value::Array(
-                    samples
-                        .iter()
-                        .map(|u| serde_json::Value::String(b64.encode(u)))
-                        .collect(),
-                );
-            }
-        }
+        // Encrypted-content samples for server-side ciphertext validation (already
+        // gathered + minimum-checked above).
+        body["units_b64"] = serde_json::Value::Array(
+            samples
+                .iter()
+                .map(|u| serde_json::Value::String(b64.encode(u)))
+                .collect(),
+        );
         // The disc's own title (UDF/ISO volume id), plain text. The key service
         // catalogs it by disc_hash (its disc-titles.json) — independent of keydb.
         if let Some(label) = ctx.title().map(str::trim) {
@@ -302,16 +328,34 @@ impl OnlineSource {
             Ok(j) => j,
             Err(_) => return Vec::new(),
         };
-        // A terminal UK is used directly (CPS unit 0 → committed cps 1, matching
-        // the old `Key::Unit(vec![(1, uk)])`).
-        if let Some(uk) = json.get("UK").and_then(|u| u.as_str()).and_then(parse_uk) {
-            return vec![UnitKey { idx: 0, key: uk }];
+        // `UK` is an ARRAY of hex keys (the service always returns an array now,
+        // even of one). A single element is the base Unit Key. A full set (one per
+        // forensic index, ordered index 1..N) is returned for a forensic sample.
+        // Preserve array order and tag each key with its array position, so the
+        // caller can map position → index (element i = index i+1). A bare string is
+        // still accepted for backward compatibility.
+        if let Some(uk) = json.get("UK") {
+            let mut out = Vec::new();
+            if let Some(s) = uk.as_str() {
+                if let Some(k) = parse_uk(s) {
+                    out.push(UnitKey::new(0, k));
+                }
+            } else if let Some(arr) = uk.as_array() {
+                for (i, v) in arr.iter().enumerate() {
+                    if let Some(k) = v.as_str().and_then(parse_uk) {
+                        out.push(UnitKey::new(i as u32, k));
+                    }
+                }
+            }
+            if !out.is_empty() {
+                return out;
+            }
         }
         // A VUK is derived to the terminal keys locally, via the disc's
         // encrypted title keys from the context — the library owns the crypto.
         if let Some(vuk) = json.get("VUK").and_then(|u| u.as_str()).and_then(parse_uk) {
             if let Ok(enc) = ctx.enc_title_keys() {
-                return uk_from_vuk(Vuk(vuk), enc);
+                return uks_from_vuk(&vuk, enc);
             }
         }
         Vec::new()
@@ -415,7 +459,7 @@ mod tests {
     /// it's the deliberate no-op stub.
     #[test]
     fn host_certs_is_noop_empty_no_network() {
-        let src = OnlineSource::new("http://example.invalid/keys", "secret");
+        let src = OnlineSource::new("http://example.test/keys", "secret");
         assert!(
             KeySource::host_certs(&src, None).is_empty(),
             "online host_certs must be an empty no-op (no network)"

tests/key_sources.rs

@@ -60,7 +60,7 @@ fn inputs(hash: &str) -> DiscInputs {
     DiscInputs {
         disc_hash: hash.into(),
         volume_id: [0u8; 16],
-        version: libfreemkv::aacs::AACS_MAJOR_UHD,
+        version: libfreemkv::aacs::mkb::AACS_MAJOR_UHD,
         mkb: Vec::new(),
         unit_key_ro: Vec::new(),
         samples: Vec::new(),
@@ -225,7 +225,7 @@ fn online_source_unconfigured_is_silent_no_op() {
 
 #[test]
 fn online_source_metadata() {
-    let src = OnlineSource::new("https://example.invalid/keys", "tok");
+    let src = OnlineSource::new("https://example.test/keys", "tok");
     assert_eq!(src.label(), "online");
     // No host-cert serving today — a no-op empty, no network touched.
     assert!(KeySource::host_certs(&src, None).is_empty());
@@ -267,10 +267,7 @@ impl KeySource for ScriptedSource {
 }
 
 fn uk(b: u8) -> UnitKey {
-    UnitKey {
-        idx: 0,
-        key: [b; 16],
-    }
+    UnitKey::new(0, [b; 16])
 }
 
 #[test]