Project State

Project Reference

See: .planning/PROJECT.md (updated 2026-02-25)

Core value: Archive impossible to unpack without knowing the format -- standard tools (7z, tar, unzip, binwalk) cannot recognize or extract contents Current focus: Milestone v1.1 Directory Support

Current Position

Phase: Not started (defining requirements) Plan: — Status: Defining requirements Last activity: 2026-02-25 — Milestone v1.1 started

Performance Metrics

Velocity (from v1.0):

Total plans completed: 10
Average duration: 3.6 min
Total execution time: 0.6 hours

Accumulated Context

Decisions

Decisions are logged in PROJECT.md Key Decisions table. Recent decisions affecting current work:

Roadmap: Format spec must precede all implementation (all three decoders build against same spec)
Roadmap: Obfuscation (XOR headers, encrypted TOC, decoy padding) deferred to Phase 6 after all decoders work without it
Phase 1: IV stored only in TOC, not duplicated in data blocks (simplifies shell dd extraction)
Phase 1: Same 32-byte key for AES-256-CBC and HMAC-SHA-256 in v1 (v2 will use HKDF)
Phase 1: Magic bytes 0x00 0xEA 0x72 0x63 (leading null signals binary)
Phase 1: HMAC scope = IV (16 bytes) || ciphertext (encrypted_size bytes)
Phase 2: Used rand::Fill::fill() for IV generation (correct rand 0.9 API)
Phase 2: Manual binary serialization with to_le_bytes/from_le_bytes (no serde/bincode)
Phase 2: Filename-only entry names (not full paths) for archive portability
Phase 2: HMAC failure skips file and continues; SHA-256 mismatch warns but writes
Phase 2: Flags bit 0 set only when at least one file is actually compressed
Phase 3: Library crate with pub mod re-exports for all 6 modules
Phase 3: Unit tests embedded in modules via #[cfg(test)] (not separate files)
Phase 3: hex-literal v1.1 for compile-time SHA-256 known-value assertions
Phase 3: Corrected HMAC golden vector (openssl pipe+xxd produced wrong value; verified with file input and Python)
Phase 3: cargo_bin! macro for non-deprecated assert_cmd binary resolution
Phase 3: 11MB deterministic pseudo-random data for large file test (wrapping_mul Knuth hash)
Phase 4: Single-file Kotlin decoder (ArchiveDecoder.kt) for simplicity and Android embeddability
Phase 4: RandomAccessFile for seeking to data blocks instead of reading entire archive into memory
Phase 4: HMAC failure skips file, SHA-256 mismatch warns but writes (matching Rust behavior)
Phase 4: Kotlin signed byte handling with .toByte() for literals > 0x7F, contentEquals() for ByteArray comparison
Phase 5: POSIX sh (not bash) for maximum busybox compatibility
Phase 5: xxd/od auto-detection at startup for hex conversion
Phase 5: Graceful HMAC degradation when openssl lacks -mac support
Phase 5: Extract ciphertext to temp file before decryption (avoids pipe buffering issues)
Phase 5: LC_ALL=C for predictable byte handling across locales
Phase 5: All 6 cross-validation tests passed on first run -- decode.sh was correct as written
Phase 5: Used sh (not bash) to invoke decode.sh in tests for POSIX compatibility validation
Phase 6: Always enable all 3 obfuscation features (no --no-obfuscate flag in v1)
Phase 6: Decoy padding range 64-4096 bytes per file (FORMAT.md allows up to 65535)
Phase 6: Shared read_archive_metadata() helper for unpack/inspect de-obfuscation
Phase 6: Two-pass TOC serialization for correct data_offsets with encrypted TOC size
Phase 6: XOR bootstrapping in Kotlin uses and 0xFF masking on BOTH operands for signed byte safety
Phase 6: Shell decoder writes de-XORed header to temp file, reuses existing read_hex/read_le_u16/read_le_u32
Phase 6: Shell decoder TOC_FILE/TOC_BASE_OFFSET abstraction for encrypted vs plaintext TOC
Phase 6: Shell decoder HMAC constructs IV from parsed hex via hex_to_bin (not archive position)

Pending Todos

None yet.

Blockers/Concerns

None.

Session Continuity

Last session: 2026-02-25 Stopped at: Starting milestone v1.1 — defining requirements Resume file: None

4.0 KiB Raw Blame History