koni_sevenz 0.9.0

7z reader and writer (incl. AES-256) for the koni_archive ecosystem, including CB7 comic archives.

Changelog

0.9.0 - 2026-07-17

• Honors the read-side size limits (ArchiveReadOptions.maxEntrySize / maxEntryCount) via the shared reader seam, plus maxContainerDecodeSize to bound 7z's bulk decodes: reading even a small entry decodes its whole (possibly compressed) header or solid folder, and this caps that decode, tightening 7z's built-in backstops (64 MiB header, 1 GiB folder) to a caller-chosen value. Those backstops still apply when the option is null.

0.8.0 - 2026-07-16

• The writer honors ArchiveWriteOptions.allowUnsafePaths (see koni_archive_core 0.8.0): with it set, an entry path is written verbatim rather than validated.

0.7.0 - 2026-07-16

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

0.6.0 - 2026-07-15

• P4-2: 7z write-side encryption. ArchiveWriteOptions.password encrypts each content folder as a compressor → AES-256-CBC chain (iterated-SHA-256 KDF, per-folder IV); ArchiveWriteOptions.encryptHeader additionally encrypts the header (-mhe), hiding entry names and requiring the password at open. Interop: real 7-Zip (7zz x -p, 7zz l -p) reads both byte-for-byte. Green on VM + dart2js + dart2wasm.
• The reader now reports entry.isEncrypted (folder-carries-an-AES-coder), matching the ZIP reader.
• First release published to pub.dev.

0.5.0 - 2026-07-15

• P3-3: 7z AES-256 decryption via ArchiveReadOptions.password. The AES coder is peeled ahead of the codec chain (decrypt into a buffer, then the existing decompress/filter path); the KDF is 7-Zip's iterated SHA-256 (UTF-16LE password), not PBKDF2. Works in solid folders and for encrypted headers (-mhe, password required at open). 7z has no password verifier, so a wrong password surfaces as corrupt data or a checksum mismatch, always typed. Interop: 7zz -p/-mhe fixtures decrypt byte-identically; green on VM + dart2js + dart2wasm.

0.4.0 - 2026-07-15

• P2-4b: format-faithful 7z writing: LZMA2 (coder 21) is the default folder coder, with LZMA (03 01 01) also selectable, powered by the new koni_codecs encoders. The header itself is LZMA-compressed (kEncodedHeader) whenever that is smaller than plain. Dictionary sized to the entry (4 KiB–8 MiB). LZMA entries buffer their uncompressed bytes while encoding (the buffer is the match window); Copy/Deflate entries still stream. Interop DoD: 7zz t/7zz x validate and extract every coder byte-for-byte, incl. >2 MiB multi-chunk LZMA2 with uncompressed-chunk fallbacks and encoded headers; the LZMA codecs are additionally liblzma-verified in koni_codecs.
• P2-4a: the 7z write container, SevenZWriter / SevenZWriteFormat: signature + start header (next-header CRC), PackInfo, UnpackInfo with per-folder CRC-32, FilesInfo (UTF-16LE names, FILETIME mtimes, unix modes, dirs, empty files, symlinks), Copy and Deflate coders, one folder per non-empty file (non-solid). Buffers packed streams until close() (the leading signature header references the trailing header, inherent to the format, documented). Solid folders remain deferred.

0.3.0 - 2026-07-15

• Lockstep release; no changes since 0.2.0.

0.2.0 - 2026-07-15

• M8: 7z reader, full scope.
  • Container: signature/start headers (CRC-verified), compressed (kEncodedHeader) headers, folders/coders/bind pairs, substreams, FilesInfo (names, mtimes, attributes, empty files/dirs).
  • Codec chains: LZMA, LZMA2, Copy, Deflate + Delta/BCJ(x86) filters.
  • Solid blocks with a size-capped LRU cache; CB7 page-flip is sub-millisecond after the first read (bench recorded).
  • BCJ2/PPMd/bzip2 → typed errors naming the codec; AES → typed encryption errors (streams at openRead, headers at open); hardening (header/folder size caps, uniform 2^53−1 integer cap, fuzz smoke in CI).
• M0: package scaffolding.