---
phase: 03-round-trip-verification
verified: 2026-02-24T21:43:47Z
status: passed
score: 10/10 must-haves verified
re_verification: false
---

# Phase 3: Round-Trip Verification Report

**Phase Goal:** Proven byte-identical round-trips through the Rust unpack command, backed by golden test vectors
**Verified:** 2026-02-24T21:43:47Z
**Status:** passed
**Re-verification:** No -- initial verification

## Goal Achievement

### Observable Truths

| # | Truth | Status | Evidence |
|---|-------|--------|----------|
| 1 | Unit tests pass for crypto module: encrypt/decrypt round-trip, HMAC compute/verify, SHA-256 known value | VERIFIED | `cargo test` output: 6 tests in `crypto::tests` all pass (encrypt_decrypt_roundtrip, encrypt_decrypt_empty, encrypted_size_formula, hmac_compute_verify, sha256_known_value, sha256_empty) |
| 2 | Unit tests pass for compression module: compress/decompress round-trip, empty data, should_compress heuristic | VERIFIED | `cargo test` output: 6 tests in `compression::tests` all pass (compress_decompress_roundtrip, compress_decompress_empty, compress_decompress_large, should_compress_text, should_not_compress_known_extensions, should_not_compress_excluded) |
| 3 | Unit tests pass for format module: header write/read round-trip, TOC entry write/read round-trip (ASCII + Cyrillic names) | VERIFIED | `cargo test` output: 7 tests in `format::tests` all pass (header_write_read_roundtrip, toc_entry_roundtrip_ascii, toc_entry_roundtrip_cyrillic, toc_entry_roundtrip_empty_name, header_rejects_bad_magic, header_rejects_bad_version, entry_size_calculation) |
| 4 | Project compiles as both library crate and binary crate | VERIFIED | `cargo test` compiles both `src/lib.rs` (lib target) and `src/main.rs` (bin target) without errors |
| 5 | Golden test vectors pass: AES-256-CBC encryption of 'Hello' with project KEY and fixed IV produces exact expected ciphertext | VERIFIED | `test_golden_aes256cbc_hello` passes: encrypt("Hello", KEY, IV=00..01) == `6e66ae8bc740efeefe83b5713fcb716f` |
| 6 | Golden test vectors pass: HMAC-SHA256 of IV\|\|ciphertext produces exact expected hash | VERIFIED | `test_golden_hmac_sha256` passes: HMAC(IV\|\|ct) == `efa09db07cb1af629d7fe9eb36f31269d80d8f5ff6b2dc565b62bc4c5719ca13` |
| 7 | Golden test vectors pass: SHA-256 of 'Hello' matches known value from FORMAT.md | VERIFIED | `test_golden_sha256_hello` passes: SHA-256("Hello") == `185f8db32271fe25f561a6fc938b2e264306ec304eda518007d1764826381969` |
| 8 | Round-trip pack->unpack produces byte-identical files for: single text file, multiple files, empty file, Cyrillic filename, large (11MB) binary | VERIFIED | 6 integration tests all pass: test_roundtrip_single_text_file, test_roundtrip_multiple_files, test_roundtrip_empty_file, test_roundtrip_cyrillic_filename, test_roundtrip_large_file, test_roundtrip_no_compress_flag |
| 9 | `cargo test --test golden` passes all golden vector tests | VERIFIED | 7 passed; 0 failed; 0 ignored |
| 10 | `cargo test --test round_trip` passes all integration tests | VERIFIED | 6 passed; 0 failed; 0 ignored |

**Score:** 10/10 truths verified

### Required Artifacts

| Artifact | Expected | Status | Details |
|----------|----------|--------|---------|
| `src/lib.rs` | Library crate re-exporting all modules | VERIFIED | 6 lines, `pub mod` for archive, cli, compression, crypto, format, key |
| `Cargo.toml` | Dev-dependencies for test infrastructure | VERIFIED | Contains tempfile, assert_cmd, hex-literal, predicates |
| `tests/golden.rs` | Golden test vectors with fixed IV/key | VERIFIED | 97 lines, 7 tests with hex-literal assertions, uses encrypted_archive::crypto and key::KEY |
| `tests/round_trip.rs` | CLI round-trip integration tests via assert_cmd | VERIFIED | 193 lines, 6 tests using tempdir + cargo_bin! + pack/unpack + assert_eq on raw bytes |
| `src/crypto.rs` | Unit tests in #[cfg(test)] module | VERIFIED | 6 unit tests (lines 80-141), covers encrypt/decrypt, HMAC, SHA-256 |
| `src/compression.rs` | Unit tests in #[cfg(test)] module | VERIFIED | 6 unit tests (lines 53-99), covers compress/decompress, should_compress |
| `src/format.rs` | Unit tests in #[cfg(test)] module | VERIFIED | 7 unit tests (lines 213-399), covers header/TOC roundtrip, Cyrillic names, error cases, size calculation |

### Key Link Verification

| From | To | Via | Status | Details |
|------|----|-----|--------|---------|
| `src/main.rs` | `src/lib.rs` | `use encrypted_archive::` imports | WIRED | Lines 2-3: `use encrypted_archive::archive`, `use encrypted_archive::cli::{Cli, Commands}` |
| `src/lib.rs` | `src/crypto.rs` | `pub mod crypto` | WIRED | Line 4: `pub mod crypto;` |
| `tests/golden.rs` | `src/crypto.rs` | `use encrypted_archive::crypto` | WIRED | Line 6: `use encrypted_archive::crypto;` |
| `tests/golden.rs` | `src/key.rs` | `use encrypted_archive::key::KEY` | WIRED | Line 7: `use encrypted_archive::key::KEY;` |
| `tests/round_trip.rs` | encrypted_archive binary | `Command::cargo_bin!("encrypted_archive")` | WIRED | Line 13: `Command::new(assert_cmd::cargo::cargo_bin!("encrypted_archive"))` |

### Requirements Coverage

| Requirement | Source Plan | Description | Status | Evidence |
|-------------|------------|-------------|--------|----------|
| INT-02 | 03-02-PLAN | Unpacked files byte-identical to originals (round-trip fidelity) | SATISFIED | 6 round-trip integration tests compare raw bytes with assert_eq!, covering single file, multiple files, empty file, Cyrillic filename, 11MB binary, APK no-compress. Unpack function verifies HMAC + SHA-256 before writing. |
| TST-01 | 03-02-PLAN | Round-trip tests: archive Rust -> dearchive Rust | SATISFIED | `tests/round_trip.rs` -- 6 tests run actual `encrypted_archive pack` then `encrypted_archive unpack` via assert_cmd, verify byte-identical output |
| TST-02 | 03-02-PLAN | Golden test vectors: known plaintext/key/IV -> expected ciphertext | SATISFIED | `tests/golden.rs` -- 7 tests with fixed IV/key produce exact expected ciphertext, HMAC, and SHA-256 values (cross-verified with openssl/Python) |
| TST-03 | 03-01-PLAN | Basic unit tests for each pipeline module | SATISFIED | 19 unit tests in #[cfg(test)] modules: crypto.rs (6), compression.rs (6), format.rs (7). Cover encrypt/decrypt, HMAC, SHA-256, compress/decompress, header/TOC serialization, error cases. |

No orphaned requirements. REQUIREMENTS.md Traceability table maps INT-02, TST-01, TST-02, TST-03 to Phase 3 -- all accounted for.

### Success Criteria Cross-Check (ROADMAP.md)

| # | Success Criterion | Status | Evidence |
|---|-------------------|--------|----------|
| 1 | Running `encrypted_archive unpack archive.bin -o output_dir/` extracts all files byte-identical to originals (verified by SHA-256 comparison) | VERIFIED | `archive::unpack()` in `src/archive.rs` (lines 232-328) performs HMAC verify, decrypt, decompress, SHA-256 verify, and writes files. Round-trip tests prove byte-identical extraction via `assert_eq!` on raw bytes. |
| 2 | Golden test vectors exist: a known plaintext + known key + known IV produces an expected ciphertext (checked in CI) | VERIFIED | `tests/golden.rs` contains 7 golden vector tests with hardcoded expected values. `cargo test --test golden` passes all 7. |
| 3 | Unit tests cover each pipeline stage independently: compression, encryption, HMAC, format serialization/deserialization | VERIFIED | 19 unit tests across 3 modules: crypto (encrypt/decrypt, HMAC, SHA-256), compression (compress/decompress, should_compress), format (header/TOC write/read, error cases, size calculation) |
| 4 | Round-trip succeeds for edge cases: empty file, large APK (>10MB), file with non-ASCII name (Cyrillic) | VERIFIED | `test_roundtrip_empty_file` -- 0-byte file; `test_roundtrip_large_file` -- 11MB deterministic binary; `test_roundtrip_cyrillic_filename` -- file named "file.txt" in Cyrillic |

### Anti-Patterns Found

| File | Line | Pattern | Severity | Impact |
|------|------|---------|----------|--------|
| - | - | None found | - | - |

No TODO/FIXME/PLACEHOLDER/HACK comments, no `unimplemented!()`, no `todo!()`, no stub implementations detected across all source and test files.

### Commit Verification

| Commit | Description | Exists |
|--------|-------------|--------|
| `ce9012c` | feat(03-01): create library crate, update main.rs imports, add dev-dependencies | Yes |
| `3e96b1e` | test(03-01): add 19 unit tests for crypto, compression, and format modules | Yes |
| `329bed6` | test(03-02): add golden test vectors for crypto primitives | Yes |
| `91ee354` | test(03-02): add CLI round-trip integration tests | Yes |

### Test Execution Results

```
cargo test (2026-02-24):
  Unit tests (src/lib.rs):     19 passed, 0 failed
  Golden vectors (tests/golden.rs):  7 passed, 0 failed
  Round-trip (tests/round_trip.rs):  6 passed, 0 failed
  Total: 32 passed, 0 failed, 0 ignored
```

### Human Verification Required

None. All phase goals are programmatically verifiable through test execution, and all tests pass.

### Gaps Summary

No gaps found. All 10 must-haves verified, all 4 requirements satisfied, all 4 ROADMAP success criteria met, all 32 tests pass, no anti-patterns detected, all key links wired.

---

_Verified: 2026-02-24T21:43:47Z_
_Verifier: Claude (gsd-verifier)_
