Files
clawhdf5/crates/clawhdf5-format
osobhandClaude Opus 5.5 e73ac2af09 fix(format): validate chunk dimensions and chunk index offsets like libhdf5
A chunk dimension of 0 read a dataset as all fill values, 0x80000000 made
an 8 GiB chunk, and a chunk dimension the chunk index's offsets are not
multiples of read chunks at the wrong place (cve-2018-11205). libhdf5
refuses all of these; now so does clawhdf5:

- DataLayout::parse (H5O__layout_decode): no chunk dimension 0 ("bad chunk
  dimension value"), at most 33 dimensions, and before layout v4 at least
  2 ("bad dimensions for chunked storage"). New
  FormatError::InvalidChunkDimensions.
- Reading a chunked dataset (H5D__chunk_init / H5D__chunk_set_sizes): the
  chunk rank must match the dataspace's and a chunk must be under 4 GiB.
  One chunked_read::chunk_geometry replaces the four copies of the rank
  check.
- v1 B-tree chunk index (H5D__btree_decode_key): every key's offsets must
  be multiples of the chunk dimensions, including the keys that only bound
  a node, which is where cve-2018-11205's bad dimension shows. New
  chunked_read::collect_chunk_info_checked; the chunked read and selection
  paths use it.

New interop test header_validation_interop.rs: h5py writes chunked files
(layout v3 and v4), the script corrupts the chunk dimension, and
clawhdf5 must read exactly the copies h5py reads.

Conformance (cached corpus, tank): 570 ok, unchanged; cve-2018-11205 now
refuses the dataset h5py refuses; six more objects that already failed now
fail with libhdf5's reason.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
2026-09-26 00:21:58 -05:00
..

clawhdf5-format

crates.io docs.rs

Pure-Rust HDF5 binary format parsing and writing — no C dependencies.

Features

  • Zero-copy superblock, object header, and B-tree parsing
  • Chunked dataset read/write with filter pipelines
  • no_std support (disable std feature)
  • Optional parallel reads via Rayon
  • SHA-256 provenance tracking

Usage

use clawhdf5_format::Superblock;

let data = std::fs::read("data.h5").unwrap();
let sb = Superblock::from_bytes(&data).unwrap();
println!("HDF5 version {}.{}", sb.version_major(), sb.version_minor());

License

MIT