libsmx/CHANGELOG.md

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased] - v0.2.0

Added

• BLS signatures (bls module, requires alloc feature)
  • bls_keygen / bls_sign / bls_verify: minimal-signature-size variant (sig ∈ G1, pk ∈ G2)
  • bls_aggregate / bls_aggregate_verify: multi-message aggregate signatures
  • bls_fast_aggregate_verify: fast aggregate verification for same-message multi-signer
  • BlsSignature::to_bytes / from_bytes: 65-byte serialization (uncompressed G1 point)
  • BlsPubKey::to_bytes / from_bytes: 128-byte serialization (uncompressed G2 point)
• BLS threshold signatures (bls::threshold module)
  • bls_threshold_keygen: Trusted Dealer mode, Shamir polynomial secret sharing
  • bls_partial_sign / bls_combine_signatures: Lagrange interpolation based aggregation
  • Supports (t+1, n) threshold configurations
• Hash-to-Curve (bls::hash_to_curve module)
  • hash_to_g1: RFC 9380 compliant, maps arbitrary message to BN256 G1 point
  • expand_message_xmd: RFC 9380 §5.3.1, message expansion using SM3 as hash
  • map_to_curve_svdw: Shallue-van de Woestijne mapping for BN256 (a=0 curve)
• fp_sqrt in sm9::fields::fp
  • Tonelli-Shanks modular square root for SM9 BN256 Fp (p ≡ 1 mod 4)
  • fp_is_square: Euler criterion based quadratic residue test
• FPE format-preserving encryption (fpe module)
  • FpeKey: 7-round Luby-Rackoff Feistel cipher based on SM4
  • Supports 1~128 bit plaintext/ciphertext domains
  • expand_tweak: arbitrary-length tweak via SM4 hash
  • Automatic key zeroization on drop (ZeroizeOnDrop)

Security

• BLS signature DST separation: signing uses BLS_SIG_SM9G1_XMD:SM3_SVDW_RO_NUL_, PoP uses a different tag
• BN256 security note: ~100-bit actual security level documented in API docs

0.1.1 - 2025-03-07

Fixed

• Fixed cargo test --no-default-features --lib compilation error
  • SM3 tests: removed alloc dependency, use manual hex parsing
  • SM4 modes tests: added #[cfg(feature = "alloc")]

Changed

• MSRV raised to 1.83.0 (required by crypto-bigint 0.6.x for ConstMontyForm constant-time Montgomery arithmetic)
• Use Rust 1.83+ built-in div_ceil method instead of manual implementation

CI

• Optimized sanity_check.sh to skip test code, avoiding false positives

0.1.0 - 2025-03-07

Added

• SM2 elliptic curve cryptography (GB/T 32918.1-5-2016)
  • Key generation, digital signature (with Z-value), public key encryption/decryption
  • Complete addition formulas for constant-time point operations
  • Fixed-window (w=4) base point scalar multiplication with precomputed table
  • Mixed Jacobian-Affine addition for optimized verification (Shamir's trick)
  • Point compression/decompression (GB/T 32918.1 section 4.2.10)
• SM3 cryptographic hash (GB/T 32905-2016)
  • Streaming and one-shot hashing API
  • HMAC-SM3 with automatic key material zeroization
• SM4 block cipher (GB/T 32907-2016)
  • Boolean circuit bitslice S-box (cache-timing resistant)
  • 8 modes of operation: ECB, CBC, OFB, CFB, CTR, GCM, CCM, XTS
  • GCM/CCM authenticated encryption with constant-time tag verification
• SM9 identity-based cryptography (GB/T 38635.1-2-2020)
  • BN256 pairing (optimal Ate with Miller loop + final exponentiation)
  • Fp12 tower extension: Fp -> Fp2(u^2+2) -> Fp6(v^3-u) -> Fp12(w^2-v)
  • Identity-based signing and verification
  • Identity-based encryption and decryption
• Unified Error enum with Display and conditional std::error::Error impl
• no_std support with optional alloc and std features
• #![forbid(unsafe_code)] enforced at crate level
• Automatic private key zeroization via zeroize::ZeroizeOnDrop
• GB/T standard test vectors for all algorithms
• Criterion benchmarks for all algorithms with baseline performance data:
  • SM3: 374 MiB/s throughput (64 KiB)
  • SM4-ECB: 27 MiB/s throughput (64 KiB)
  • SM2 sign: 258 µs, verify: 316 µs
  • SM9 sign: 3.44 ms, verify: 5.50 ms

Changed

• MSRV raised to 1.83.0 (required by crypto-bigint 0.6.x for ConstMontyForm constant-time Montgomery arithmetic)

Security

• GCM gf128_mul: replaced secret-dependent if branches with mask arithmetic
• SM2 is_infinity: replaced short-circuit Iterator::all with ConstantTimeEq
• SM2 add: replaced 3 conditional branches with complete addition formulas + conditional_select
• SM2 double: replaced if is_infinity() with conditional_select
• HMAC-SM3: added zeroize for k_pad/ipad/opad key material on stack
• CCM: reject AAD > 510 bytes instead of silently skipping
• XTS: reject non-16-byte-aligned input instead of silently truncating
• SM9 hash_to_range: replaced variable-iteration while loop with constant-time conditional select