From b04b7b1c2cb61e7635bd38f083183d5eb8138be6 Mon Sep 17 00:00:00 2001 From: NikitolProject Date: Wed, 25 Feb 2026 02:36:57 +0300 Subject: [PATCH] docs(phase-6): complete phase execution --- .planning/ROADMAP.md | 2 +- .../06-VERIFICATION.md | 93 +++++++++++++++++++ 2 files changed, 94 insertions(+), 1 deletion(-) create mode 100644 .planning/phases/06-obfuscation-hardening/06-VERIFICATION.md diff --git a/.planning/ROADMAP.md b/.planning/ROADMAP.md index aae03e8..2cc6821 100644 --- a/.planning/ROADMAP.md +++ b/.planning/ROADMAP.md @@ -121,4 +121,4 @@ Phases execute in numeric order: 1 -> 2 -> 3 -> 4 -> 5 -> 6 | 3. Round-Trip Verification | 2/2 | Complete | 2026-02-24 | | 4. Kotlin Decoder | 1/1 | Complete | 2026-02-24 | | 5. Shell Decoder | 2/2 | Complete | 2026-02-24 | -| 6. Obfuscation Hardening | 2/2 | Complete | 2026-02-25 | +| 6. Obfuscation Hardening | 2/2 | Complete | 2026-02-24 | diff --git a/.planning/phases/06-obfuscation-hardening/06-VERIFICATION.md b/.planning/phases/06-obfuscation-hardening/06-VERIFICATION.md new file mode 100644 index 0000000..06c1476 --- /dev/null +++ b/.planning/phases/06-obfuscation-hardening/06-VERIFICATION.md @@ -0,0 +1,93 @@ +--- +phase: 06-obfuscation-hardening +verified: 2026-02-24T23:32:25Z +status: human_needed +score: 4/4 +re_verification: false +human_verification: + - test: "Run Kotlin cross-validation tests with kotlinc/java installed" + expected: "All 6 tests pass (Rust pack -> Kotlin decode -> SHA-256 match)" + why_human: "kotlinc and java are not available in the current environment; Kotlin code is structurally verified but not runtime-tested" +--- + +# Phase 6: Obfuscation Hardening Verification Report + +**Phase Goal:** Archive format resists casual analysis -- binwalk, file, strings, and hex editors reveal nothing useful +**Verified:** 2026-02-24T23:32:25Z +**Status:** human_needed +**Re-verification:** No -- initial verification + +## Goal Achievement + +### Observable Truths + +| # | Truth | Status | Evidence | +|---|-------|--------|----------| +| 1 | File table (names, sizes, offsets) is encrypted with its own IV -- hex dump of archive reveals no plaintext metadata | VERIFIED | TOC encrypted via `crypto::encrypt_data(&toc_plaintext, &KEY, &toc_iv)` in archive.rs:162,195. `strings` on archive reveals no filenames. Tested with multi-file archive -- no "hello", "test", ".txt" in output. | +| 2 | All headers are XOR-obfuscated with a fixed key -- no recognizable structure patterns in first 256 bytes | VERIFIED | First bytes of archive are `a5d6 e46c e074 4cc8` instead of `00ea7263`. XOR_KEY `[0xA5, 0x3C, 0x96, 0x0F, 0xE1, 0x7B, 0x4D, 0xC8]` applied in archive.rs:216-217 via `format::xor_header_buf()`. | +| 3 | Random decoy padding exists between data blocks -- file boundaries are not detectable by size analysis | VERIFIED | `rng.random_range(64..=4096)` generates random padding (archive.rs:111). Random bytes written after each ciphertext block (archive.rs:231). `inspect` shows `Padding after: 1718 bytes` for test archive. | +| 4 | All three decoders (Rust, Kotlin, Shell) still produce byte-identical output after obfuscation is applied | VERIFIED (partial: Kotlin not runtime-tested) | Rust: 38 cargo tests pass (25 unit + 7 golden + 6 round-trip). Shell: 7/7 cross-validation tests pass. Kotlin: code structurally correct (XOR bootstrapping, TOC decryption) but kotlinc/java not available in environment. | + +**Score:** 4/4 truths verified (1 needs human runtime confirmation for Kotlin) + +### Required Artifacts + +| Artifact | Expected | Status | Details | +|----------|----------|--------|---------| +| `src/format.rs` | XOR_KEY constant, xor_header_buf(), read_header_auto() with XOR bootstrapping | VERIFIED | XOR_KEY at line 13, xor_header_buf() at line 85, read_header_auto() at line 149, write_header_to_buf() at line 95, serialize_toc() at line 171, read_toc_from_buf() at line 182, parse_header_from_buf() at line 111. 6 new XOR-related unit tests (lines 509-661). | +| `src/archive.rs` | Updated pack() with TOC encryption + decoy padding + XOR header; updated unpack()/inspect() with de-obfuscation | VERIFIED | pack() at line 58: TOC encryption (lines 160-163), decoy padding (lines 111-113), XOR header (lines 216-217). read_archive_metadata() shared helper at line 32 for unpack/inspect de-obfuscation. | +| `src/crypto.rs` | generate_iv() used for toc_iv | VERIFIED | generate_iv() at line 8, encrypt_data() at line 18, decrypt_data() at line 34. Used by archive.rs for toc_iv generation. | +| `kotlin/ArchiveDecoder.kt` | XOR_KEY constant, xorHeader(), TOC decryption, updated decode() | VERIFIED | XOR_KEY at line 39, xorHeader() at line 266, XOR bootstrapping in decode() at line 293-296, TOC decryption at lines 302-315. | +| `shell/decode.sh` | XOR_KEY_HEX, XOR de-obfuscation loop, TOC decryption via openssl, TOC_FILE abstraction | VERIFIED | XOR_KEY_HEX at line 107, hex_to_bin() at line 113, XOR bootstrapping loop at lines 138-161, header temp file parsing at lines 164-181, TOC decryption at lines 188-204, TOC_FILE/TOC_BASE_OFFSET abstraction throughout TOC parsing loop. | +| `kotlin/test_decoder.sh` | Cross-validation tests using obfuscated archives | VERIFIED | 5 test cases (single text, multiple files, no-compress, empty file, large file) with SHA-256 verification. | +| `shell/test_decoder.sh` | Cross-validation tests using obfuscated archives | VERIFIED | 6 test cases (single text, multiple files, no-compress, empty file, large file, Cyrillic filename) with SHA-256 verification. All 7 file verifications pass. | + +### Key Link Verification + +| From | To | Via | Status | Details | +|------|----|-----|--------|---------| +| archive.rs pack() | format.rs xor_header_buf() | XOR applied to 40-byte header buffer after write_header_to_buf | WIRED | archive.rs:216 `write_header_to_buf`, line 217 `xor_header_buf` | +| archive.rs pack() | crypto.rs encrypt_data() | TOC plaintext buffer encrypted with toc_iv | WIRED | archive.rs:162 `crypto::encrypt_data(&toc_plaintext, &KEY, &toc_iv)`, line 195 re-encryption with correct offsets | +| archive.rs unpack()/inspect() | format.rs read_header_auto() + crypto.rs decrypt_data() | XOR bootstrapping on header, then TOC decryption | WIRED | read_archive_metadata() at line 32-51: read_header_auto (line 34), decrypt_data for TOC (line 43) | +| kotlin decode() | xorHeader() | XOR bootstrapping on header bytes before parseHeader | WIRED | ArchiveDecoder.kt:293-296: magic check, xorHeader(headerBytes) call | +| kotlin decode() | decryptAesCbc() | Encrypted TOC bytes decrypted with tocIv before parseToc | WIRED | ArchiveDecoder.kt:307 `decryptAesCbc(encryptedToc, header.tocIv, KEY)` | +| shell decode.sh | openssl enc -d | Encrypted TOC extracted and decrypted | WIRED | decode.sh:192 dd extract, lines 195-197 openssl decrypt, TOC_FILE variable set to decrypted temp file | + +### Requirements Coverage + +| Requirement | Source Plan | Description | Status | Evidence | +|-------------|-----------|-------------|--------|----------| +| FMT-06 | 06-01, 06-02 | XOR-obfuscation of headers with fixed key | SATISFIED | XOR_KEY constant identical across all 3 implementations. Header bytes obfuscated -- first 4 bytes are `a5d6e46c` not `00ea7263`. XOR bootstrapping in all decoders. | +| FMT-07 | 06-01, 06-02 | Encrypted file table with separate IV | SATISFIED | TOC encrypted via AES-256-CBC with random toc_iv stored in header. All 3 decoders decrypt TOC before parsing entries. `strings` reveals no filenames. | +| FMT-08 | 06-01, 06-02 | Decoy padding (random data between blocks) | SATISFIED | Random padding 64-4096 bytes per file (archive.rs:111). Random bytes via `rand::Fill` (line 113). All decoders use absolute data_offset from TOC entries, naturally skipping padding. | + +### Anti-Patterns Found + +| File | Line | Pattern | Severity | Impact | +|------|------|---------|----------|--------| +| src/archive.rs | 140,148 | "placeholder" in comment about data_offset=0 | Info | Not a stub -- placeholder offsets are immediately replaced with real values at line 185 in the two-pass algorithm. No issue. | + +### Human Verification Required + +### 1. Kotlin Cross-Validation Tests + +**Test:** Run `bash kotlin/test_decoder.sh` on a system with kotlinc and java installed +**Expected:** All 6 tests pass (Rust pack with obfuscation -> Kotlin decode -> SHA-256 match) +**Why human:** kotlinc and java are not installed in the current environment. The Kotlin code is structurally verified (XOR_KEY, xorHeader(), TOC decryption all present and correctly wired), but has not been runtime-tested in this verification cycle. + +### Gaps Summary + +No gaps found. All four success criteria from the ROADMAP are met: + +1. **File table encrypted with its own IV** -- hex dump reveals no plaintext metadata (verified with `strings` scan) +2. **Headers XOR-obfuscated** -- no recognizable structure in first bytes (verified: `a5d6e46c` instead of `00ea7263`) +3. **Random decoy padding between blocks** -- file boundaries not detectable (verified: `Padding after: 1718 bytes` in inspect output) +4. **All three decoders produce byte-identical output** -- Rust 38/38 tests pass, Shell 7/7 cross-validation pass, Kotlin structurally verified (needs runtime confirmation) + +All 38 Rust tests pass (25 unit + 7 golden + 6 round-trip integration). All 7 Shell cross-validation tests pass. The only item requiring human action is running the Kotlin cross-validation tests with kotlinc/java installed. + +Requirements FMT-06, FMT-07, FMT-08 are all satisfied with implementation evidence across all three decoder implementations. + +--- +_Verified: 2026-02-24T23:32:25Z_ +_Verifier: Claude (gsd-verifier)_