# Changelog

All notable changes to Zupt are documented in this file.
Format follows [Keep a Changelog](https://keepachangelog.com/).

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## [1.5.0] — 2026-03-28

### Added — Jasmin Assembly Integration (Sprint 1)
- **`zupt_mac_verify_ct`** Jasmin assembly linked into `zupt_decrypt_buffer()`. Replaces the C XOR accumulation loop for HMAC-SHA256 comparison. 4×u64 unrolled XOR, proven constant-time by Jasmin type system. Symbol confirmed active via `nm`: `T zupt_mac_verify_ct`.
- **`zupt_ct_select_32`** Jasmin assembly linked into `zupt_mlkem768_decaps()`. Replaces the C `cmov()` function for Fujisaki-Okamoto implicit rejection key selection. 4×u64 masked select, proven constant-time. Symbol confirmed active via `nm`: `T zupt_ct_select_32`.
- **`include/zupt_jasmin.h`** — extern declarations for all Jasmin functions with ABI documentation.
- **`#ifdef ZUPT_USE_JASMIN`** dispatch guards in `zupt_crypto.c` and `zupt_mlkem.c` with clean C fallback.
- **Makefile** auto-detects `jasmin/*.s` files, assembles to `.o`, links into binary, sets `-DZUPT_USE_JASMIN`.

### Not Wired (documented, requires upstream fixes)
- `zupt_fe_cswap` (X25519): Jasmin uses 4×u64 limbs, C uses 5×u51-bit — incompatible layout. C fallback active.
- `zupt_aes256_blk` (AES-NI): Assembly has stack offset bug (`[rsp+1]` instead of `[rsp+16]`). C table-based AES active.

### Changed
- Version: 1.4.0 → 1.5.0.
- `cmov()` in `zupt_mlkem.c` guarded with `#ifndef ZUPT_USE_JASMIN`.
- MAC comparison return type widened from `uint8_t` to `uint64_t` to match Jasmin signature.

### Security
- 53/53 tests pass with Jasmin linked. 13/13 NIST vectors. ASAN clean. Zero warnings.

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## [1.4.0] — 2026-03-28

### Fixed — Jasmin Parse Errors (jasminc 2026.03.0)
All 4 `.jazz` files rewritten to fix compilation errors:

- **`zupt_mac_verify.jazz`**: `diff |= a ^ b` — compound XOR+OR not a single x86-64 op. Split into `tmp = a; tmp ^= b; diff |= tmp`.
- **`zupt_mlkem_select.jazz`**: `out.[i] = (8u)sel` — `reg ptr` is read-only. Changed to `reg u64 out_ptr` with raw pointer writes.
- **`zupt_x25519_fe.jazz`**: `a.[i] = ta ^ diff` — same const-ptr write. Changed to `reg u64 a_ptr`.
- **`zupt_aes_ctr.jazz`**: Memory syntax `(u128)[ptr]` → `u128[ptr]` → `[ptr]` — all wrong. Correct: `key.[0]` via `reg ptr u128[N]` for reads; `stack u128[15]` for writes; bare `[ptr + 0]` for u64-width.
- Uninitialized variable warning: `#VPXOR(zero, zero)` → `wipe = rk.[z]; wipe ^= wipe; rk.[z] = wipe`.

### Changed
- Removed all `-CT` flag references (does not exist in jasminc 2026.03.0).
- CT enforced by Jasmin type system during normal compilation.
- Safety: `jasminc -arch x86-64 -checksafety`.
- All compound expressions split into separate register operations.
- All output parameters changed from `reg ptr` to `reg u64` raw pointers.
- Byte-level access avoided: 4×u64 instead of 32×u8.

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## [1.3.0] — 2026-03-28

### Added
- `include/zupt_acsl.h` — ACSL predicates: `ValidBuffer`, `ValidWriteBuffer`, `Separated2`, `KeyWiped`, `ValidKey`.
- `SECURITY_REVIEW.md` — 8-section security review with per-function CT analysis table.
- `jasmin/README.jazz.md` — build instructions, CT verification explanation, error history.

### Fixed
- First round of Jasmin syntax fixes (partial — completed in v1.4.0).

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## [1.2.0] — 2026-03-28

### Added — CPUID Runtime Detection
- **`src/zupt_cpuid.c`** + **`include/zupt_cpuid.h`** — runtime detection of AES-NI, PCLMUL, AVX2, SSE4.1 via CPUID. Supports GCC/Clang, MSVC, and inline assembly fallback.
- `zupt_detect_cpu()` called at program start. Global `zupt_cpu` struct for dispatch.

### Added — Jasmin Source Files (initial)
- 4 `.jazz` files created for AES-CTR, MAC verify, X25519, ML-KEM select.
- **Note:** All had parse errors — fixed in v1.3.0–v1.4.0.

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## [1.1.0] — 2026-03-28

### Fixed — Critical Cryptographic Bugs

- **X25519 Montgomery formula** (`zupt_x25519.c`): `AA + 121666*E` → `BB + 121666*E`. The doubling formula was algebraically wrong. DH exchanges produced consistently wrong but matching values, so PQ archives worked. RFC 7748 test vectors exposed the bug. **All X25519 in v0.7.0–v1.0.0 was not interoperable with any other implementation.**
- **Dead `match_cost()`** (`zupt_lzh.c`): Defined but never called. Removed (Clang `-Wunused-function`).
- **ML-KEM `const polyvec`** warnings: C11 doesn't support multi-level const for arrays-of-arrays. Removed `const` (matches pqcrystals reference).
- **`__int128` pedantic** warning: Wrapped with `#pragma GCC diagnostic push/pop`.

### Added
- **`tests/test_vectors.c`** — 13 NIST/RFC test vectors: SHA-256 (3), HMAC-SHA256 (2), SHA3-256 (2), SHAKE-128 (1), X25519 (2), ML-KEM-768 (2), XXH64 (1).

### Changed
- Zero warnings on GCC + Clang with `-Wall -Wextra -Wpedantic`.

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## [1.0.0] — 2026-03-21

### Stable Release
- **Archive format frozen at v1.4.** `FORMAT_STABLE` flag set. Future changes require v2.0.
- Documentation: FORMAT.md, AUDIT.md, FUZZING.md, SECURITY.md.
- **License: GPL-3.0 → MIT.**

### Fixed — ML-KEM-768 Bugs (5 critical)
1. **`poly_basemul` OOB**: `zetas[64+i]` accessed past 128-entry array. Fixed to 64 iterations.
2. **Missing `poly_tomont()` in keygen**: Public key in wrong Montgomery domain.
3. **Inverted `cmov` in FO decaps**: C integer promotion caused rejection key selected on valid ciphertext. Fixed: `(-(int64_t)diff) >> 63`.
4. **`inv_ntt` wrong zetas table**: Separate wrong table. Fixed: reuse `zetas[]`, k counts 127→0.
5. **PQ nonce mismatch**: Encrypt/decrypt independently generated nonces. Fixed: store in header.

### Added — Post-Quantum Hybrid Encryption (v0.7.0)
- **ML-KEM-768** (FIPS 203): ~658 lines pure C11. NTT, Barrett/Montgomery, CBD, FO transform.
- **X25519** (RFC 7748): ~270 lines. Montgomery ladder, constant-time fe_cswap.
- **Keccak-f[1600]**: SHA3-256/512, SHAKE-128/256. ~215 lines.
- **Hybrid KEM**: `SHA3-512(ml_ss XOR x25519_ss ‖ transcript)`. Secure if EITHER holds.
- `zupt keygen` subcommand, `--pq <keyfile>` flag.
- Key file format: ZKEY magic, ML-KEM pk(1184B) + X25519 pk(32B) + optional sk + XXH64.
- 10-test PQ suite.
- Format v1.3 → v1.4 with `enc_type` dispatch byte.

### Added — Multi-Threaded Compression (v0.6.0)
- `-t <N>` flag. Batch-parallel pipeline. 14-test MT suite.
- Solid mode falls back to N=1 (shared LZ context).

### Added — Security Hardening (v0.5.1)
- 16 bug fixes: Huffman Kraft violation (data corruption), heap-buffer-overflows, removed `rand()` fallback, constant-time MAC, secure key wipe, LE serialization, realloc checks, empty file checksum.

### Core Features (v0.1.0–v0.4.0)
- LZ77+Huffman compression (1MB window, near-optimal parsing).
- AES-256-CTR + HMAC-SHA256 authenticated encryption.
- PBKDF2-SHA256 (600,000 iterations).
- Per-block XXH64 integrity. Recursive directory backup. Solid mode.

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## Summary

| Version | Key Change | Tests |
|---------|-----------|-------|
| **1.5.0** | Jasmin assembly linked: MAC verify + ML-KEM select **active** in binary | 53+13 PASS |
| **1.4.0** | All 4 `.jazz` files compile on jasminc 2026.03.0 | 53+13 PASS |
| **1.3.0** | ACSL predicates, security review, partial Jasmin fixes | 53+13 PASS |
| **1.2.0** | CPUID detection, Jasmin source files (with errors) | 53+13 PASS |
| **1.1.0** | X25519 BB formula fix, 13 NIST/RFC test vectors | 53+13 PASS |
| **1.0.0** | Format frozen v1.4, ML-KEM bugs fixed, MIT license | 40 PASS |

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© 2026 Cristian Cezar Moisés — MIT License