============================================
CCC Rust Milestone 1 — Completion Record
============================================

:Status: Complete
:Date: 2026-02-26
:Repository: ``ccc_rust``
:Milestone: 1 (Pure Rust crypto library)

Related Documents
=================

* Milestone 2 planning/session state:
  ``docs/ccc_rust_milestone2_session_state.rst``

Overview
========

Milestone 1 delivers a provider-based Rust cryptography workspace with:

* a stable trait/type core crate,
* a wolfSSL-backed provider crate,
* and a conformance test binary validating NIST/RFC vectors.

Milestone 1 is intentionally isolated from Flutter/Dart integration concerns.

Scope and Boundaries
====================

Delivered in Milestone 1
------------------------

* Workspace scaffold and cross-target build aliases.
* ``ccc-crypto-core`` with algorithm enums, traits, registry, error/types.
* ``ccc-crypto-wolfssl`` provider with AEAD/KDF/MAC/Hash/KEM support.
* Conformance runner with NIST/RFC vectors and pass/fail gate output.
* Architecture and phase-tracking documentation.

Out of scope for Milestone 1
----------------------------

* ``flutter_rust_bridge`` integration.
* Dart bindings and Flutter plugin packaging.
* LetUsMsg app integration wiring.
* ML-KEM and Classic McEliece runtime implementation (declared, deferred).

Crate Dependency Graph
======================

::

    +------------------------+
    | tests/conformance      |
    | ccc-conformance-tests  |
    +-----------+------------+
                |
                v
    +------------------------+         +-------------------------+
    | crates/ccc-crypto-     |  uses   | vendors/wolfssl         |
    | wolfssl                +-------->+ (C library submodule)   |
    +-----------+------------+         +-------------------------+
                |
                v
    +------------------------+
    | crates/ccc-crypto-core |
    | traits + enums + types |
    +------------------------+

Implementation Summary
======================

Core crate (``ccc-crypto-core``)
--------------------------------

* Algorithm enums with fixed ``u32`` discriminants for cross-layer compatibility.
* Provider trait surfaces:
  * ``AeadProvider``
  * ``KdfProvider``
  * ``MacProvider``
  * ``HashProvider``
  * ``KemProvider``
  * ``CryptoProvider``
* ``ProviderRegistry`` (global, lazy-initialized registry model).
* Core result/error and crypto data types, including zeroized key material handling.

wolfSSL provider crate (``ccc-crypto-wolfssl``)
------------------------------------------------

* AEAD: AES-256-GCM, ChaCha20-Poly1305, XChaCha20-Poly1305.
* KDF: HKDF-SHA256/384/512, Argon2id, BLAKE2b-based KDF path.
* MAC: HMAC-SHA256/384/512, BLAKE2b-MAC, constant-time verification.
* Hash: SHA-256/384/512, SHA3-256/512, BLAKE2b-512.
* KEM: X25519 and X448 keygen/encap/decap.
* Startup capability probing and benchmark hooks.

Conformance suite
-----------------

* NIST SP 800-38D AES-GCM vectors.
* RFC 8439 ChaCha20-Poly1305 vectors.
* RFC 5869 HKDF vectors.
* RFC 4231 HMAC vectors.
* FIPS/reference hash vectors.
* RFC 7748 X25519/X448 DH vectors.
* XChaCha20-Poly1305 extended-nonce roundtrip + auth-failure checks.

Algorithm ID Mapping (u32)
==========================

Authoritative source: ``crates/ccc-crypto-core/src/algorithms.rs``.

KDF
---

* ``1``  -> ``KdfAlgorithm::Sha256``
* ``2``  -> ``KdfAlgorithm::Sha384``
* ``3``  -> ``KdfAlgorithm::Sha512``
* ``4``  -> ``KdfAlgorithm::Blake2b512``
* ``5``  -> ``KdfAlgorithm::Argon2id``
* ``6``  -> ``KdfAlgorithm::Kmac256``

AEAD
----

* ``12`` -> ``AeadAlgorithm::AesGcm256``
* ``13`` -> ``AeadAlgorithm::ChaCha20Poly1305``
* ``14`` -> ``AeadAlgorithm::XChaCha20Poly1305``
* ``15`` -> ``AeadAlgorithm::Ascon128a``

MAC
---

* ``30`` -> ``MacAlgorithm::HmacSha256``
* ``31`` -> ``MacAlgorithm::HmacSha384``
* ``32`` -> ``MacAlgorithm::HmacSha512``
* ``33`` -> ``MacAlgorithm::Blake2bMac``
* ``35`` -> ``MacAlgorithm::Poly1305``

Hash
----

* ``40`` -> ``HashAlgorithm::Sha256``
* ``41`` -> ``HashAlgorithm::Sha384``
* ``42`` -> ``HashAlgorithm::Sha512``
* ``43`` -> ``HashAlgorithm::Blake2b512``
* ``44`` -> ``HashAlgorithm::Sha3_256``
* ``45`` -> ``HashAlgorithm::Sha3_512``

KEM
---

* ``50`` -> ``KemAlgorithm::X25519``
* ``51`` -> ``KemAlgorithm::X448``
* ``52`` -> ``KemAlgorithm::MlKem768`` (deferred)
* ``53`` -> ``KemAlgorithm::MlKem1024`` (deferred)
* ``54`` -> ``KemAlgorithm::ClassicMcEliece460896`` (deferred)

Verification Gate (Milestone 1)
================================

All required gate items are complete:

* ``[x]`` ``cargo test --workspace``
* ``[x]`` ``cargo run -p ccc-conformance-tests`` → ``ALL VECTORS PASSED``
* ``[x]`` ``cargo build --target aarch64-apple-ios``
* ``[x]`` ``cargo build --target aarch64-linux-android``
* ``[x]`` No ``flutter_rust_bridge`` / Dart / Flutter dependency in workspace
* ``[x]`` ``cargo audit`` (0 vulnerabilities)

Milestone 2 Handoff Contract
============================

Milestone 2 (plugin repository) must consume Milestone 1 outputs without
changing Milestone 1 algorithm IDs or trait semantics.

Handoff inputs
--------------

* ``ccc-crypto-core`` public trait + type API.
* ``ccc-crypto-wolfssl`` provider behavior validated by conformance gates.
* Algorithm discriminant mapping above.

Milestone 2 responsibilities
----------------------------

* Add bridge crate and ``flutter_rust_bridge`` in Milestone 2 repo only.
* Implement DTO-safe bridge calls (init/capabilities/aead/kdf/mac/hash/kem/self-test).
* Generate Dart bindings and package plugin targets.