h5rs (dump, ls, diff, check --data) kept its own lenient VL decoder:
a heap object longer than its element was cut to the element's length
(libhdf5 and h5py refuse it), a null string printed "" where h5dump
prints NULL, the stored element size was trusted, and every heap
collection was kept as an owned copy for the whole run. It now resolves
each element with VlResolver::element / string_element (new: one element
in place, borrowing from the file), and refuses a VL type whose stored
element size is not 4 + offset size + 4, as File does. H5::heap_object
and its cache are gone. h5diff compares a null VL string equal to an
empty one; so does h5rs diff.
clawhdf5-wasm already resolved VL strings with read_vl_strings; it now
uses VlResolver and checks the stored element size before reading, as
File::read_string does.
Tests (h5py writes the files, patched for "a\0b", a null element and
mis-sized heap objects, with 8- and 4-byte offsets):
- h5rs_interop dump_prints_vl_data_like_h5dump: byte-identical to h5dump;
- dump_json_vl_values_match_h5py: h5py's values, errors where h5py fails;
- check_data_flags_mis_sized_vl_heap_objects;
- clawhdf5-wasm tests/vl_strings.rs: wasm, File and h5py agree.
All four fail before. check --data over the 150 cve_hdf5 CVE and fuzzer
files now passes 15 (h5dump rejects 8 of them), was 16 and 9: the
stored-size check flags cve-2024-32608. h5rs-check-ok-files.sh --data:
0 of 422 flagged; h5rs-fuzz.sh: clean on 180 files.
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
New workspace crate clawhdf5-tools with one binary, h5rs, built only on the
clawhdf5 facade and clawhdf5-format (no libhdf5, no C):
- ls [-r] [-v] FILE[/path]: h5ls's listing (same text in its first two
columns) plus the datatype; -v adds address, link count, layout and chunk
index, chunk size, storage, filters, datatype and attributes.
- dump [--json] [-A] [-p] [-d PATH] FILE: h5dump DDL (byte-identical to
h5dump 1.14.6 on the test files) or hdf5-json.
- stat FILE: h5stat's object/link/rank/layout/filter/attribute counts, raw
data and total size.
- diff [-r] [-q] [-d D] [-p R] A B [OBJ1 [OBJ2]]: structural and value
differences, exit 0/1/2 like h5diff.
- check [--data] FILE: walks every object, parses every message, verifies
the checksums of every v2+ structure (including the fractal heap blocks
the library never checks), checks chunk indexes against their datasets
and raw data for out-of-file or overlapping extents; every problem with
its address.
Values over --max-bytes are reported, not read; dense-storage heaps are
verified before objects are read from them; panics are caught (exit 3).
Tests compare with h5ls, h5stat, h5dump and h5diff and with h5py's values,
and flip the checksum of every checksummed structure in a v1.14-format file.
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
