android-encrypted-archiver/.planning/phases/03-round-trip-verification/03-02-SUMMARY.md

---
phase: 03-round-trip-verification
plan: 02
subsystem: testing
tags: [golden-vectors, integration-tests, round-trip, aes-256-cbc, hmac-sha256, sha256, assert_cmd, tempfile]

# Dependency graph
requires:
  - phase: 03-round-trip-verification
    plan: 01
    provides: "Library crate (src/lib.rs) with pub mod re-exports, dev-dependencies (assert_cmd, tempfile, hex-literal)"
  - phase: 02-core-archiver
    provides: "crypto.rs, compression.rs, format.rs, archive.rs with pack/unpack CLI"
provides:
  - "7 golden test vectors for AES-256-CBC, HMAC-SHA256, and SHA-256 (deterministic, cross-verified)"
  - "6 CLI round-trip integration tests covering all Phase 3 edge cases"
  - "32 total tests (19 unit + 7 golden + 6 integration) all passing"
affects: [phase-4-cli-polish, phase-5-shell-decoder, verification]

# Tech tracking
tech-stack:
  added: []
  patterns: [golden-vector-testing-with-fixed-iv, cli-integration-via-assert_cmd-cargo_bin-macro, tempdir-isolation-for-parallel-tests]

key-files:
  created: [tests/golden.rs, tests/round_trip.rs]
  modified: []

key-decisions:
  - "Corrected HMAC golden vector: research openssl pipe+xxd gave wrong value; verified with openssl file input and Python hmac module"
  - "Used cargo_bin! macro instead of deprecated Command::cargo_bin() for forward compatibility"
  - "Large file test uses 11MB deterministic pseudo-random data with --no-compress to avoid gzip non-determinism"

patterns-established:
  - "Golden vector pattern: fixed IV + known KEY for deterministic crypto test output"
  - "CLI integration pattern: tempdir + cargo_bin! + pack/unpack + assert_eq on raw bytes"
  - "Edge case coverage: empty file (PKCS7), Cyrillic UTF-8 names, >10MB files, APK no-compress"

requirements-completed: [INT-02, TST-01, TST-02]

# Metrics
duration: 5min
completed: 2026-02-24
---

# Phase 3 Plan 02: Golden Vectors and Round-Trip Tests Summary

**7 golden crypto test vectors (AES-256-CBC, HMAC-SHA256, SHA-256) and 6 CLI round-trip integration tests covering empty files, Cyrillic filenames, and 11MB binaries**

## Performance

- **Duration:** 5 min
- **Started:** 2026-02-24T21:34:17Z
- **Completed:** 2026-02-24T21:39:45Z
- **Tasks:** 2
- **Files created:** 2

## Accomplishments
- Created 7 golden test vectors with fixed IVs for deterministic crypto verification (TST-02)
- Created 6 CLI round-trip integration tests proving byte-identical pack->unpack (INT-02, TST-01)
- All 32 tests pass (19 unit + 7 golden + 6 integration) with zero warnings
- Cross-verified golden values with openssl (file input) and Python hmac module

## Task Commits

Each task was committed atomically:

1. **Task 1: Create golden test vectors with fixed IV/key** - `329bed6` (test)
2. **Task 2: Create CLI round-trip integration tests** - `91ee354` (test)

## Files Created/Modified
- `tests/golden.rs` - 7 golden vector tests: AES-256-CBC encrypt/decrypt/empty, HMAC-SHA256 compute/verify, SHA-256 x2
- `tests/round_trip.rs` - 6 CLI integration tests: single file, multiple files, empty, Cyrillic, 11MB large, APK no-compress

## Decisions Made
- Corrected HMAC golden vector from research: openssl pipe with xxd -r -p produced incorrect binary, verified correct value (`efa09db0...`) using openssl with file input and Python hmac.new()
- Used `cargo_bin!` macro (non-deprecated) instead of `Command::cargo_bin()` to avoid deprecation warnings
- Large file test generates 11MB of deterministic pseudo-random data (`i.wrapping_mul(2654435761) as u8`) to ensure reproducibility

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 1 - Bug] Corrected HMAC-SHA256 golden vector value**
- **Found during:** Task 1 (golden test vectors)
- **Issue:** Research openssl cross-verification produced wrong HMAC value (`0c85780b...`) due to pipe+xxd binary corruption; correct value is `efa09db0...`
- **Fix:** Computed correct value independently with Python hmac module and openssl file-based input, updated golden vector
- **Files modified:** tests/golden.rs
- **Verification:** All 7 golden tests pass; value matches Rust hmac crate, Python hmac, and openssl (file)
- **Committed in:** 329bed6 (Task 1 commit)

**2. [Rule 1 - Bug] Replaced deprecated assert_cmd API**
- **Found during:** Task 2 (round-trip tests)
- **Issue:** `Command::cargo_bin()` deprecated in assert_cmd 2.1 with warning about custom cargo build-dir incompatibility
- **Fix:** Used `cargo_bin!("encrypted_archive")` macro which resolves at compile time via `CARGO_BIN_EXE_` env var
- **Files modified:** tests/round_trip.rs
- **Verification:** Zero deprecation warnings, all 6 round-trip tests pass
- **Committed in:** 91ee354 (Task 2 commit)

---

**Total deviations:** 2 auto-fixed (2 bugs)
**Impact on plan:** Both fixes necessary for correctness and clean builds. No scope change.

## Issues Encountered
None

## User Setup Required
None - no external service configuration required.

## Next Phase Readiness
- Phase 3 fully complete: 32 tests (19 unit + 7 golden + 6 integration) all pass
- All Phase 3 success criteria met: byte-identical round-trips, golden vectors, unit tests, edge cases (empty, >10MB, Cyrillic)
- Ready for Phase 4 (CLI polish) or Phase 5 (shell decoder)

## Self-Check: PASSED

- All 2 key files exist on disk: tests/golden.rs, tests/round_trip.rs
- Both task commits verified: 329bed6, 91ee354
- cargo test: 32 passed (19 unit + 7 golden + 6 integration), 0 failed

---
*Phase: 03-round-trip-verification*
*Completed: 2026-02-24*