From f93dddf40c4eb347cca9778f012b0e9a04f255a7 Mon Sep 17 00:00:00 2001
From: Matthew Jackson <1085847+MattJackson@users.noreply.github.com>
Date: Fri, 3 Jul 2026 20:36:50 -0700
Subject: [PATCH] keydb: adopt corrected mk_from_dk (2-arg), reviving the
 DK->MK fallback
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libfreemkv's AACS work changes mk_from_dk from (dk, mkb, vid) to (dk, mkb) —
the VID enters at the VUK step, not the MK step. Adopt the 2-arg call so the DK
pool is tried unconditionally (no longer gated on a VID being present), matching
libfreemkv. Without this keysources fails to compile against the new libfreemkv.
(Equivalent to the stranded b80d4cb; applied directly since that branch had
diverged surrounding context.)
---
 src/keydb.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/keydb.rs b/src/keydb.rs
index 6854b35..32ccce9 100644
--- a/src/keydb.rs
+++ b/src/keydb.rs
@@ -207,7 +207,9 @@ impl KeydbSource {
                     .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()));
+                    // 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(|| mk_from_dk(&db.device_keys, mkb).ok());
                 match (mk, vid) {
                     (Some(mk), Some(vid)) => uk_from_vuk(vuk_from_mk(mk, vid), enc_title_keys),
                     // Locked VID-per-path rule: an MK with no VID cannot derive.