koni_codecs 0.9.0

Pure Dart compression codecs (deflate, LZMA/LZMA2 — decode and encode) and crypto primitives, usable standalone or inside the koni_archive ecosystem.

Changelog

0.9.0 - 2026-07-17

• Lockstep release; no changes to this package since 0.8.0.

0.8.0 - 2026-07-16

• Lockstep release; no changes to this package since 0.7.0.

0.7.0 - 2026-07-16

• Lockstep release; no changes to this package since 0.6.0.

0.6.0 - 2026-07-15

• No code changes; the AES/CBC/CTR/SHA/HMAC/PBKDF2 primitives (crypto.dart) are now used by the write side too (7z AES-256, ZIP WinZip AES). Docs updated from "read" to "read and write"; the non-constant-time / no-zeroization caveats are unchanged.
• First release published to pub.dev.

0.5.0 - 2026-07-15

• P3-1: cryptographic primitives for the Phase 3 decryption work, in the new package:koni_codecs/crypto.dart entrypoint: AES-128/192/256 (T-table, encrypt + decrypt), CBC and the WinZip little-endian CTR mode, SHA-1, SHA-256, HMAC, and PBKDF2. Zero-dependency, standards-defined (FIPS-197, SP 800-38A, FIPS 180-4, RFC 2104/8018), vector-tested, and dart2js/dart2wasm-exact. Not constant-time (archive reading, not a TLS stack), documented as such.

0.4.0 - 2026-07-15

• P2-4b: LZMA/LZMA2 compression: LzmaEncoder, Lzma2Encoder, and the carry-aware RangeEncoder, the encode direction of the M8 decoders (identical probability-model layout, lockstep updates). Hash-chain match finder over an input-scaled table with rep-distance matches and a one-step lazy heuristic (7-Zip fast-mode shape; optimal parsing is a deferred ratio lever). LZMA2 framing with per-chunk range-coder restart, uncompressed-chunk fallback for incompressible spans, and state-reset resynchronization. Buffer-based one-shot API mirroring the decoders (the input buffer is the window). Output is byte-identical on VM, dart2js, and dart2wasm (golden-pinned) and decodes under liblzma (CPython interop: FORMAT_ALONE for LZMA1, FORMAT_RAW for LZMA2) and our own decoders; ratio lands within ~1 point of liblzma preset 6 on repo docs (bench recorded).

• P2-3: DeflateEncoder (raw DEFLATE, RFC 1951), the compression counterpart of InflateDecoder, added for the ZIP writer. Greedy LZ77 (hash-chain matching) with fixed-Huffman blocks, ≤ 32 KiB blocks (bounded memory, no cross-block matches). dart:convert Converter idiom (one-shot or startChunkedConversion) over the resumable RawDeflater engine. Output is universally decodable, differential-tested against dart:io zlib and Info-ZIP unzip, not just our own inflater. Ratio improvements (lazy matching, dynamic Huffman) are deferred; correctness and portability (VM/dart2js/dart2wasm) come first. Bench recorded in bench/results/.

0.3.0 - 2026-07-15

• Lockstep release; no changes since 0.2.0.

0.2.0 - 2026-07-15

• M8: LZMA (LzmaDecoder), LZMA2 (Lzma2Decoder), and branch filters (deltaDecode, bcjX86Decode), implemented from the public-domain LZMA specification, differential-tested against liblzma (CPython vectors), chunk-driven with buffer-backed windows.

0.1.0 - 2026-07-15

• M4: inflate + gzip codecs.
  • InflateDecoder (raw DEFLATE, RFC 1951): chunk-driven synchronous state machine, vector-tested standalone (CPython-zlib references, degenerate dynamic Huffman, stored-block boundaries, dart:io zlib differential), with an inflate_fast-style hot loop (bench recorded).
  • GzipDecoder (RFC 1952): multi-member, FNAME/FEXTRA/FCOMMENT/FHCRC, per-member CRC-32 + ISIZE verification, gzip(1)-compatible trailing-garbage tolerance.
  • Resumable engines (RawInflater, RawGzipDecoder) exported for framing layers.
• M1: BitReader, LSB-first (DEFLATE bit order) bit cursor over byte buffers, with byte alignment and aligned whole-byte reads. Malformed input throws FormatException (the package's documented error idiom; see doc/notes.md).
• M0: package scaffolding: pub workspace membership, shared strict lints, CI matrix (VM on Linux/macOS/Windows; web via dart2js and dart2wasm).