Changelog

2026-03-17

Added AES-XTS and SM4-XTS APIs in symm and root wrappers:
- bytes APIs: Encrypt*/Decrypt*XTS
- data-unit indexed APIs: Encrypt*/Decrypt*XTSAt
- stream APIs: Encrypt*/Decrypt*XTSStream
- stream + data-unit indexed APIs: Encrypt*/Decrypt*XTSStreamAt
Added XTS master-key split helpers:
- SplitXTSMasterKey
- SplitAesXTSMasterKey
- SplitSM4XTSMasterKey
Added XTS parameter validation and explicit no-CTS behavior:
- dual keys must be non-empty and equal length
- dataUnitSize must be a positive multiple of 16
- non-stream input must be 16-byte aligned
- stream tail must be 16-byte aligned
Added key-derivation APIs in hashx and root wrappers:
- DerivePBKDF2SHA256Key (crypto/pbkdf2, stdlib)
- DerivePBKDF2SHA512Key (crypto/pbkdf2, stdlib)
- DeriveArgon2idKey / DeriveArgon2iKey (golang.org/x/crypto/argon2)
- Argon2Params + DefaultArgon2idParams
Added benchmark coverage for symmetric hot paths:
- AES/SM4 GCM, CCM, XTS
- AES/SM4 XTS stream path
Added file random fill APIs:
- FillWithRandom (math/rand pseudo-random)
- FillWithCryptoRandom (crypto/rand secure random, may be slower)
Added HMAC verify APIs (bytes + hex wrappers) in macx and root package.
Added XTS standard-vector tests (IEEE P1619 subset) and XTS fuzz tests.
Added CCM/XTS related test coverage for root wrappers and symm.

Refactored XTS internals to reduce duplication via shared factory/path.
Switched AEAD options behavior to require explicit Nonce (no IV fallback in GCM/CCM paths).
Reworked CFB-8 register update to ring-buffer state handling.
Refined README.md structure and added:
- XTS usage/constraints documentation
- AEAD nonce non-reuse requirement
- AEAD CipherOptions nonce-only behavior note
- legacy GCM/CCM stream decryption memory warning
- FillWithRandom vs FillWithCryptoRandom guidance
- XTS dataUnitIndex mapping consistency note

Introduced subpackages and root wrappers:
- asymm, symm, hashx, encodingx, paddingx, filex, legacy, macx.
Added Chinese README.md and Apache-2.0 LICENSE.
Added SM9 support in asymmetric APIs.
Added ChaCha20 and ChaCha20-Poly1305 APIs (memory + stream wrappers where applicable).
Added unified symmetric cipher options API:
- CipherOptions{Mode, Padding, IV, Nonce, AAD}.
Added AEAD APIs and wrappers:
- AES-GCM, SM4-GCM, AES-CCM, SM4-CCM (bytes + chunk + stream helper APIs).
Added more symmetric mode coverage for SM4:
- ECB/CBC/CFB/OFB/CTR (bytes + stream derived APIs).
Added comprehensive tests across packages and root wrappers.
Added fuzz tests for paddingx, encodingx, and symm round-trip invariants.

Refactored monolithic implementation to subpackage architecture while preserving root-package convenience APIs.
AES mode APIs now support generic mode selection and derived mode helpers.
Stream APIs expanded across AES/SM4/DES/3DES and ChaCha20.
Updated docs to include a security-first recommendation and algorithm capability matrix.
Updated dependencies and modules for current code paths (gmsm, x/crypto).