# Project State

## Project Reference

See: .planning/PROJECT.md (updated 2026-02-24)

**Core value:** Archive impossible to unpack without knowing the format -- standard tools (7z, tar, unzip, binwalk) cannot recognize or extract contents
**Current focus:** Phase 2: Core Archiver

## Current Position

Phase: 2 of 6 (Core Archiver) -- COMPLETE
Plan: 2 of 2 in current phase -- COMPLETE
Status: Phase 2 complete, ready for Phase 3
Last activity: 2026-02-24 -- Pack/unpack/inspect archive commands

Progress: [███░░░░░░░] 33%

## Performance Metrics

**Velocity:**
- Total plans completed: 3
- Average duration: 4.3 min
- Total execution time: 0.2 hours

**By Phase:**

| Phase | Plans | Total | Avg/Plan |
|-------|-------|-------|----------|
| 1. Format Specification | 1 | 7 min | 7 min |
| 2. Core Archiver | 2/2 | 6 min | 3 min |

**Recent Trend:**
- Last 5 plans: 7min, 4min, 2min
- Trend: improving

*Updated after each plan completion*

## 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

### Pending Todos

None yet.

### Blockers/Concerns

- Open question: Does target busybox have `openssl enc -aes-256-cbc` with `-K`/`-iv` flags? (affects Phase 5)
- Open question: Is `xxd` available in target busybox? Fallback: `od` (affects Phase 5; spec includes od fallback functions)
- RESOLVED: HMAC uses same key as AES in v1 (decided in Phase 1 spec, v2 will use HKDF)

## Session Continuity

Last session: 2026-02-24
Stopped at: Completed 02-02-PLAN.md (Pack/unpack/inspect archive commands)
Resume file: None