182 lines
7.2 KiB
Markdown
182 lines
7.2 KiB
Markdown
# CCC Rust – Session State (2026-02-25)
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Paste this into a fresh Copilot context to resume.
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---
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## Milestone 1 – Verification Gate Progress
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| Gate item | Status |
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|---|---|
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| `cargo test --workspace` | ✅ passing |
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| `cargo run -p ccc-conformance-tests` ALL VECTORS PASSED | ✅ passing |
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| `cargo build --target aarch64-apple-ios` | ✅ passing |
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| `cargo build --target aarch64-linux-android` | ✅ passing |
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| No flutter_rust_bridge / Dart dependency | ✅ confirmed |
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| `cargo audit` | ✅ passing (0 vulnerabilities) |
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---
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## Todo List
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- [x] Add KEM conformance vectors (RFC 7748 X25519 + X448) to `tests/conformance/src/main.rs`
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- [x] Fix KEM RFC vector correctness (updated to canonical RFC 7748 §6.1 / §6.2 values)
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- [x] Fix XChaCha20-Poly1305 zero-key/zero-nonce failure (`-173 BAD_FUNC_ARG`) by removing invalid probe
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- [x] Verify all conformance tests pass (`ALL VECTORS PASSED`)
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- [x] Install `cargo-audit` and verify no known CVEs
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- [x] `cargo build --target aarch64-apple-ios` — success
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- [x] `cargo build --target aarch64-linux-android` — success
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- [x] Write `docs/ccc_rust_milestone1.rst`
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- [x] Update `docs/ccc_rust_plan_phases.rst` to mark completed items
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---
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## Files Changed This Session
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### `tests/conformance/src/main.rs`
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- Added `KemAlgorithm` to imports
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- Added `KemDhVec` struct and `XChaChaProbe` struct
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- Added `KEM_DH_VECS` static with RFC 7748 §6.1 (X25519) and §6.2 (X448) vectors
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- Corrected KEM vectors to canonical RFC 7748 Diffie-Hellman values
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- Added `XCHACHA20_PROBES` static and later removed invalid all-zero nonce probe
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- Added `run_kem()` — RFC 7748 KAT test (both Alice→Bob and Bob→Alice)
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- Added `run_kem_roundtrip()` — ephemeral keygen + encap/decap self-consistency
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- Added `run_xchacha20_kat()` — roundtrip + auth-failure check, prints ct_tag for pinning
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- Updated `main()` to call those 3 new runners
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### `crates/ccc-crypto-wolfssl/build.rs`
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- Added to bindgen allowlist:
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- `wc_curve25519_import_private_ex`
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- `wc_curve25519_import_public_ex`
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- `wc_curve25519_export_key_raw_ex`
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- `wc_curve448_import_private_ex`
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- `wc_curve448_import_public_ex`
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- `wc_curve448_export_key_raw_ex`
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- These are now confirmed present in `wolfcrypt_bindings.rs` (verified via `nm`)
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### `crates/ccc-crypto-wolfssl/src/kem.rs`
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- Added `const X25519_LE: i32 = 0` (EC25519_LITTLE_ENDIAN) and `const X448_LE: i32 = 0`
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- `x25519_generate()`: export now uses `wc_curve25519_export_key_raw_ex(..., X25519_LE)`
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- `x25519_dh()`: import private uses `wc_curve25519_import_private_ex(..., X25519_LE)`,
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import public uses `wc_curve25519_import_public_ex(..., X25519_LE)`,
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DH uses `wc_curve25519_shared_secret_ex(..., X25519_LE)`
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- Same pattern applied to `x448_generate()`, `x448_dh()` with `X448_LE`
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- Temporary debug logging used during investigation was removed after validation
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### `crates/ccc-crypto-wolfssl/src/lib.rs`
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- Added a manual `ECPoint` definition with `#[repr(C, align(16))]`
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- Rationale: preserve ABI layout compatibility for `curve25519_key` fields after `ECPoint`
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- This removed prior `-170` (`ECC_BAD_ARG_E`) failures and restored X25519 roundtrip
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---
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## Current Conformance Test Output
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```
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── KEM DH (RFC 7748) ────────────────────────────────────────────────
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[PASS] X25519 DH RFC 7748 §6.1 (Alice→Bob)
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[PASS] X25519 DH RFC 7748 §6.1 (Bob→Alice)
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[PASS] X448 DH RFC 7748 §6.2 (Alice→Bob)
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[PASS] X448 DH RFC 7748 §6.2 (Bob→Alice)
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── KEM Roundtrip ────────────────────────────────────────────────────
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[PASS] X25519 ephemeral roundtrip
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[PASS] X448 ephemeral roundtrip
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── XChaCha20-Poly1305 extended-nonce ────────────────────────────────
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[INFO] XChaCha20-Poly1305 extended-nonce roundtrip ct_tag =
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bd6d179d3e83d43b9576579493c0e939... ← printed for pinning
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[PASS] XChaCha20-Poly1305 extended-nonce roundtrip [roundtrip]
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[PASS] XChaCha20-Poly1305 extended-nonce roundtrip [auth-fail]
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ALL VECTORS PASSED ✓
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```
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---
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## Root Cause Analysis
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### KEM mismatch root cause resolved
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The remaining KEM mismatches were caused by non-canonical values in the conformance
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vectors. `tests/conformance/src/main.rs` now uses the canonical RFC 7748 §6.1/§6.2
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Diffie-Hellman vectors, and both X25519 and X448 pass in both directions.
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### XChaCha20 zero-key/zero-nonce – resolved in test suite
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`-173` = `BAD_FUNC_ARG`. wolfSSL's `wc_XChaCha20Poly1305_Encrypt` rejects an all-zero
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nonce as an invalid argument. This is a wolfSSL security guard.
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The invalid zero-nonce probe was removed from conformance tests.
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---
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## Recommended Next Steps (for next session)
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### Fix 1 – KEM: finish RFC vector correctness
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✅ Completed — vectors corrected to RFC 7748 canonical values.
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### Fix 2 – XChaCha20: remove zero-nonce probe
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✅ Completed — removed invalid all-zero nonce probe.
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After removing it, pin the ct_tag printed by `run_xchacha20_kat`:
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```
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bd6d179d3e83d43b9576579493c0e939572a1700252bfaccbed2902c21396cbb731c7f1b0b4aa644a8d50d95afe27fb7d5fe6e0539a2d3ad
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```
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for regression pinning.
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### Fix 3 – After conformance passes
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Run in order:
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```bash
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cargo install cargo-audit
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cargo audit
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cargo build --target aarch64-apple-ios
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# ensure Android NDK clang toolchain is in PATH first
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cargo build --target aarch64-linux-android
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```
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Status:
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- ✅ `cargo install cargo-audit`
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- ✅ `cargo audit --json` (`"found": false`, `"count": 0`)
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- ✅ `cargo build --target aarch64-apple-ios`
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- ✅ `cargo build --target aarch64-linux-android`
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Environment note:
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- Android build was unblocked by creating NDK compiler aliases:
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- `aarch64-linux-android-clang` -> `aarch64-linux-android21-clang`
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- `aarch64-linux-android-clang++` -> `aarch64-linux-android21-clang++`
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in `.../ndk/26.3.11579264/toolchains/llvm/prebuilt/darwin-x86_64/bin`.
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Documentation status:
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- ✅ `docs/ccc_rust_milestone1.rst` created
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- ✅ `docs/ccc_rust_plan_phases.rst` updated to reflect Milestone 1 completion
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---
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## Key File Paths
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```
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ccc_rust/
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├── crates/ccc-crypto-wolfssl/
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│ ├── build.rs ← bindgen allowlist updated
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│ └── src/kem.rs ← LE endianness fix + clean DH path (conformance passing)
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├── tests/conformance/src/main.rs ← RFC 7748 vectors corrected + XChaCha probe cleanup
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└── docs/
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├── ccc_rust_plan.rst ← architecture plan
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├── ccc_rust_plan_phases.rst ← phase tracking (needs update after fixes)
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└── session_state_2026-02-25.md ← this file
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```
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## Wolfssl options confirmed
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- `WOLF_CRYPTO_CB` = **undefined** (`#undef` in installed `wolfssl/options.h`)
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- `WOLFSSL_ASYNC_CRYPT` = **not enabled** (`WOLFSSL_ASYNC_THREADS:BOOL=no` in CMakeCache)
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- `WOLFSSL_SE050` = **not defined**
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- bindgen clang args: `-DHAVE_AESGCM -DHAVE_CHACHA -DHAVE_POLY1305 -DHAVE_XCHACHA
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-DHAVE_BLAKE2 -DHAVE_BLAKE2B -DWOLFSSL_SHA384 -DWOLFSSL_SHA512 -DWOLFSSL_SHA3
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-DHAVE_HKDF -DHAVE_CURVE25519 -DHAVE_CURVE448`
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- **Missing clang arg that may help:** `-DWOLFSSL_NOSHA3_256` or any align flags if
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ECPoint differs between bindgen and compiled struct
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