Files
libfreemkv/tests/pass_n_patch_fix.rs
T
Matthew Jackson 1894fa1a49 libfreemkv 1.7.4: single drive-owned AACS bus-removal point
Relocate AACS bus decryption to one spot at the bottom of the sector chain:
the Drive's SectorSource impl applies decrypt_bus_in_content (gated to
encrypted-content ranges), with the stage decided once from the unlock/
handshake result (BusStage::from_read_data_key). Remove read_data_key from
DecryptKeys::Aacs and AacsState and the two downstream decrypt_bus call sites;
every reader (key sampler, mux, unit-key validation) now sees already-de-bussed
content and never reasons about bus encryption. Add BusRemovalSectorSource
stream + tests; keep the AacsBusKeyUnavailable fail-loud gate.
2026-09-19 13:59:52 -07:00

100 lines
3.4 KiB
Rust

//! Regression tests for Pass N (patch) fix — decrypt key inversion bug.
//!
//! Tests that decrypt_sectors is invoked correctly when opts.decrypt=true.
//! The 2026-05-03 bug at `libfreemkv/src/disc/mod.rs:1938-1942` inverted
//! the decrypt key arms, causing patch to pass DecryptKeys::None on encrypted discs.
use libfreemkv::{aacs, decrypt::DecryptKeys};
/// Test: decrypt_sectors with DecryptKeys::None is a no-op.
#[test]
fn decrypt_sectors_with_none_keys_is_noop() {
let mut sector = vec![0x42u8; 2048];
let mut keys = DecryptKeys::None;
let result = libfreemkv::decrypt::decrypt_sectors(&mut sector, &mut keys, 0);
assert!(result.is_ok());
assert_eq!(
&sector[..],
&[0x42u8; 2048][..],
"DecryptKeys::None should not modify buffer"
);
}
/// Test: decrypt_sectors with CSS keys descrambles sectors.
#[test]
fn css_decrypt_of_an_uncrackable_sector_still_descrambles() {
// Wrong key: the header crib rejects it and re-crack finds nothing, but that
// is not a rip failure — `attack_crib` is a heuristic, so this mismatch just
// means the cached key stands (CSS recoverability varies per sector, unlike AACS).
let mut sector = vec![0xFFu8; 2048];
// Scrambled DVD sectors are MPEG-2 PS packs. The descramble policy requires
// the pack start code as well as the flag bits, because byte 0x14 means
// something else entirely in an IFO, UDF or ISO 9660 sector.
sector[0x00..0x04].copy_from_slice(&[0x00, 0x00, 0x01, 0xBA]);
sector[0x14] |= 0x30; // CSS scramble flag, bits 4-5
let title_key: [u8; 5] = [0x42, 0x13, 0x37, 0xBE, 0xEF];
let mut keys = DecryptKeys::Css { title_key };
let dropped = libfreemkv::decrypt::decrypt_sectors(&mut sector, &mut keys, 0)
.expect("a crib false positive must not fail the rip");
assert_eq!(dropped, 0, "CSS reports no loss term of its own");
assert_eq!(
sector[0x14] & 0x30,
0x00,
"the sector is descrambled with the cached key, which clears the flag"
);
}
/// Test: AACS unit encryption detection works.
#[test]
fn aacs_encryption_flag_detection() {
// A clear unit: TS syncs (0x47) intact at every 192-byte packet.
let mut unit = vec![0u8; aacs::content::ALIGNED_UNIT_LEN];
let mut off = 4;
while off < aacs::content::ALIGNED_UNIT_LEN {
unit[off] = 0x47;
off += 192;
}
// Encryption is the scrambled body (TS syncs destroyed), NOT a flag bit.
assert!(aacs::content::is_clean(
&unit,
libfreemkv::disc::ContentFormat::BdTs
));
// Flag bits on a synced unit do not make it look encrypted.
unit[0] = 0xC0;
unit[7] = 0xC0;
assert!(aacs::content::is_clean(
&unit,
libfreemkv::disc::ContentFormat::BdTs
));
// Scrambled body (syncs gone) → encrypted.
let scrambled = vec![0x99u8; aacs::content::ALIGNED_UNIT_LEN];
assert!(!aacs::content::is_clean(
&scrambled,
libfreemkv::disc::ContentFormat::BdTs
));
}
/// Test: DecryptKeys::is_encrypted() correctly identifies encrypted state.
#[test]
fn decrypt_keys_is_encrypted_variants() {
let none = DecryptKeys::None;
assert!(!none.is_encrypted());
let aacs = DecryptKeys::Aacs {
unit_keys: vec![],
format: libfreemkv::disc::ContentFormat::BdTs,
};
assert!(aacs.is_encrypted());
let css = DecryptKeys::Css {
title_key: [0u8; 5],
};
assert!(css.is_encrypted());
}