llm-ingestion-okf/tests/test_asset_limits.py
Kjell Tore Guttormsen 0c3c4904ee
fix(assets): bound every link of the filter chain, and cover the backstop
The two findings of the 18.09 PM checkpoint of `0f308c1`. Red tests landed
first in `3b587ea`; this is what turns them green.

BLOCKER -- `_check_inflated` read `filters[0]`, measured that one link and
returned, which is not a bound: a PDF decodes a stream through a LIST of
filters. Measured in paired subprocesses from two pinned trees, idle machine:

  [/FlateDecode]        400 MB  408 516 B   59 232 256 ->    62 017 536 B
  [/FlateDecode x2]     400 MB    1 636 B  886 554 624 ->    52 367 360 B
  [/FlateDecode x3]     400 MB    1 070 B  889 393 152 ->    61 390 848 B
  [/FlateDecode x2]     1,2 GB    2 927 B  2 567 204 864 ->  60 403 712 B

542 000x the file at two links, and the picture WAS refused at the end -- by
`check_payload` after `get_data()`, once the memory was spent. The single-link
row is the control and does not move. It also left the 16 corpus objects behind
an `[/ASCII85Decode /FlateDecode]` chain unmeasured, since `filters[0]` is not
`FlateDecode` there.

`_check_stream_cost` walks every link. THREE CLASSES and no fourth
(`extract.bounded_pdf_filters`, pinned by a test): `FlateDecode` MEASURED, a
link with another expanding link behind it inflated under the same bound and
handed on; `ASCII85Decode`/`ASCIIHexDecode` bounded by their own input because
they SHRINK; `DCTDecode`/`JPXDecode`/`JBIG2Decode` PASS THROUGH. Everything
else -- `LZWDecode`, `RunLengthDecode`, `CCITTFaxDecode`, `/Crypt`, anything
written later -- is refused UNREAD with a new code `asset_pdf_unbounded`,
decided before the FIRST link is decoded so a document cannot make the run pay
for the links in front of the one we cannot bound. An encrypted stream is
deciphered and then measured, where `stream.decipher is not None` used to
return unmeasured; 0 of 5 142 objects here are in an encrypted document, which
is why nothing caught it.

NOT ONE PICTURE CHANGES HANDS, AND IT IS MEASURED BY NAME. Every PDF on this
machine -- 78 documents, K2 in both trinn1 and trinn2, the shipped fixtures and
R761 -- run through `_pdf_images` page by page from both pinned trees:

  images carried          9 356 -> 9 356
  documents losing one              0 of 78
  documents gaining one             0 of 78
  asset_pdf_unsupported     322 -> 314
  asset_pdf_unbounded         0 -> 8

The 8 are the 4 `CCITTFaxDecode` stencil masks (`/ImageMask true`,
`/BitsPerComponent 1`), counted twice because trinn1 and trinn2 hold the same
document. They were refused before and are refused now, one step earlier and
under a code that says why.

MAJOR -- `check_payload(len(data))` after `get_data()` is the counted refusal
four documentation surfaces point at, and deleting exactly that line passed all
2 132 tests. It is reachable through a stream pdfminer has ALREADY decoded
(`decode()` sets `rawdata` to `None`), which is now the ONLY case outside the
bound and has a test.

Eight mutations, one line each, every one DEAD, with the unmutated tree run
first as the control: first-link-only, loop dropped, inequality reversed,
encrypted skipped, backstop deleted, unknown filter passed through,
intermediate link not carried forward, whole check removed.

`tools/okf_accounting_gate.py` gains one line, the new code in
`REJECTION_CODES` -- what a rejection code requires and nothing more. Gate
unchanged: exit 1, GATE RED rows 2, 3, 6. Version stays 0.10.1, untagged.

Suite after `git add` against a clean tree: `uv run pytest -q` ->
2152 passed, 1 skipped (226 s). ruff, ruff format --check, mypy --strict clean.

Report: docs/2026-09-18-filterkjeden-og-backstoppen.md

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-18 15:34:07 +02:00

732 lines
31 KiB
Python

"""Two findings of the independent 0.10.0 review, as red tests (0.10.1).
Both land with the SHIPPED defaults (`--assets` on, `--gate
guard-trusted-source`), and both are new in 0.10.0 -- before it, no reader
read an `<img>` attribute or opened an image stream at all.
1. **A remote image reference became a LIVE markdown image link** in the
persisted concept, carrying an address the document's author controls,
query string included. This package opens no socket, but a consumer that
renders the markdown or lets an agent fetch images does, which turns "a
bundle was opened" into a beacon. The guard's `user-upload` tier refuses
such a line and the build's default tier does not, so the same bytes are
persisted under the default and refused one tier up.
2. **Nothing bounded a PDF image's size.** A 9.6 KB file declaring an
8000x8000 grayscale image of compressed zeros made `encode_png` allocate
width*height bytes twice over; measured peak RSS 83 MB at 3000x3000 and
276 MB at 8000x8000, linear in the pixel count. One such document -- or
one legitimately enormous scan -- takes the whole batch build with it,
before any gate, because the guard never sees image bytes.
The limit is READ OFF the corpora rather than chosen: over the 4 828 image
objects of the 43-document reference corpus the largest is 4 515 x 4 128
(18.6 MP, a landscape drawing), and over R761's 109 delivered pictures the
largest is 2 072 x 656 (1.4 MP). `MAX_IMAGE_PIXELS` sits above both with
room to spare, and anything larger is a counted refusal rather than a
killed build.
"""
from __future__ import annotations
import re
import subprocess
import sys
import zlib
from pathlib import Path
import pytest
from llm_ingestion_okf import assets, cli
from llm_ingestion_okf.assets import IMAGE_POINTER, render_missing
from llm_ingestion_okf.errors import ExtractionError
from llm_ingestion_okf.extract import extract_document
FIXTURES = Path(__file__).parent / "fixtures" / "image-inbox"
REMOTE = "https://collect.example.net/p.gif?doc=drift&u=SESSION"
#: Any markdown image whose target is not this bundle's own `assets/`.
FOREIGN_IMAGE_LINK = re.compile(r"!\[[^\]\n]*\]\(\s*(?!/assets/)([^)\s]+)")
# --- finding 1: a remote reference is inert ---------------------------------
def test_a_remote_reference_is_not_a_markdown_image_link() -> None:
line = render_missing(REMOTE, reason="the source is off this machine", label="fig", href=REMOTE)
assert "](" not in line
assert REMOTE in line, "the address is still stated -- a reader must see what was there"
def test_the_pointer_block_of_a_carried_image_is_unchanged() -> None:
"""The known-positive beside it: a local image keeps its image block, or
the fix has merely disarmed the whole capability."""
image = assets.read_image((FIXTURES / "graphics" / "figur-84-1.png").read_bytes(), name="f.png")
assert IMAGE_POINTER.search(assets.render_block(image)) is not None
@pytest.mark.parametrize(
"document",
[
'<html><body><p>A</p><img src="{ref}" alt="fig"></body></html>',
'<standard xmlns:xlink="http://www.w3.org/1999/xlink"><body><sec><title>T</title>'
'<p>A</p><graphic xlink:href="{ref}"/></sec></body></standard>',
],
ids=["html", "sts"],
)
@pytest.mark.parametrize("ref", [REMOTE, "//collect.example.net/p.gif", "HTTPS://EVIL/p.gif"])
def test_no_reader_writes_a_live_link_for_a_remote_reference(document: str, ref: str) -> None:
"""A property over the readers that resolve references, not one string."""
suffix = ".html" if document.startswith("<html") else ".xml"
# `&` is an entity opener in XML, so the reference is escaped for that
# reader and not for the HTML one.
escaped = ref if suffix == ".html" else ref.replace("&", "&amp;")
extracted = extract_document(
f"doc{suffix}", document.format(ref=escaped).encode("utf-8"), assets=True
)
foreign = FOREIGN_IMAGE_LINK.findall(extracted.text)
assert foreign == [], f"live image link(s) {foreign} for {ref}"
assert ref.split("?")[0].lower() in extracted.text.lower()
def test_a_data_uri_image_is_carried_and_leaves_no_foreign_link() -> None:
png = (FIXTURES / "graphics" / "figur-84-1.png").read_bytes()
import base64
uri = "data:image/png;base64," + base64.b64encode(png).decode("ascii")
extracted = extract_document(
"doc.html", f'<html><body><img src="{uri}"></body></html>'.encode(), assets=True
)
assert len(extracted.images) == 1
assert FOREIGN_IMAGE_LINK.findall(extracted.text) == []
def test_a_built_bundle_carries_no_foreign_image_link(tmp_path: Path) -> None:
"""The shipped fixture inbox holds one remote `<img>`; the bundle must
point at `assets/` and nowhere else."""
pytest.importorskip("pdfplumber")
pytest.importorskip("pypandoc")
bundle = tmp_path / "bundle"
code = cli.main(
[
"build",
str(FIXTURES),
"--bundle",
str(bundle),
"--bundle-id",
"limits",
"--okf-version",
"0.2",
]
)
assert code == 0
foreign: list[str] = []
for path in bundle.rglob("*.md"):
foreign += FOREIGN_IMAGE_LINK.findall(path.read_text(encoding="utf-8"))
assert foreign == []
# --- finding 2: a declared size that is too large is refused, not decoded ---
def _zeros_stream(total: int) -> bytes:
"""`total` bytes of zeros, deflated WITHOUT ever holding them.
The generator has to stay cheaper than the bomb it builds, or the test
measures its own fixture instead of the code under test.
"""
compressor = zlib.compressobj(9)
chunk = b"\x00" * (1 << 20)
parts = [compressor.compress(chunk) for _ in range(total >> 20)]
parts.append(compressor.flush())
return b"".join(parts)
def _nested_zeros_stream(total: int, links: int = 2) -> bytes:
"""The same zeros, deflated `links` times over -- the shape a PDF declares
as `/Filter [/FlateDecode /FlateDecode]`.
Deflate output of a long run of zeros is itself highly repetitive, so the
second pass shrinks 407 685 bytes to 795: the whole 400 MB stands behind
under a kilobyte of stream, which is why measuring only the first link of
the chain is not a bound at all.
"""
stream = _zeros_stream(total)
for _ in range(links - 1):
stream = zlib.compress(stream, 9)
return stream
def _bomb(
dimension: int,
content: bytes | None = None,
payload: bytes | None = None,
filters: str = "/FlateDecode",
) -> bytes:
"""A tiny PDF declaring one `dimension` x `dimension` grayscale image of
compressed zeros -- the review's own repro, built here. `content` replaces
the page's content stream, for a page that draws an INLINE image instead.
`payload` replaces the image stream, for a document whose DECLARED size and
whose actual stream are two different numbers. `filters` replaces the
`/Filter` entry, for a document whose stream is decoded by a CHAIN rather
than by one filter."""
if payload is None:
payload = zlib.compress(b"\x00" * (dimension * dimension), 9)
if content is None:
content = b"BT /F1 12 Tf 20 100 Td (bomb) Tj ET\nq 100 0 0 100 20 20 cm /Im0 Do Q\n"
objects = [
b"<< /Type /Catalog /Pages 2 0 R >>",
b"<< /Type /Pages /Kids [3 0 R] /Count 1 >>",
b"<< /Type /Page /Parent 2 0 R /MediaBox [0 0 200 200] /Resources << /XObject "
b"<< /Im0 5 0 R >> /Font << /F1 6 0 R >> >> /Contents 4 0 R >>",
b"<< /Length %d >>\nstream\n" % len(content) + content + b"\nendstream",
(
"<< /Type /XObject /Subtype /Image /Width %d /Height %d /ColorSpace /DeviceGray "
"/BitsPerComponent 8 /Filter %s /Length %d >>\nstream\n"
% (dimension, dimension, filters, len(payload))
).encode("ascii")
+ payload
+ b"\nendstream",
b"<< /Type /Font /Subtype /Type1 /BaseFont /Helvetica >>",
]
out = bytearray(b"%PDF-1.4\n")
offsets = []
for number, body in enumerate(objects, start=1):
offsets.append(len(out))
out += b"%d 0 obj\n" % number + body + b"\nendobj\n"
start = len(out)
out += b"xref\n0 %d\n0000000000 65535 f \n" % (len(objects) + 1)
for offset in offsets:
out += b"%010d 00000 n \n" % offset
out += b"trailer\n<< /Size %d /Root 1 0 R >>\nstartxref\n%d\n%%%%EOF\n" % (
len(objects) + 1,
start,
)
return bytes(out)
def test_the_limit_is_above_every_image_measured_in_the_corpora() -> None:
"""4 515 x 4 128 = 18.6 MP is the largest of the 4 828 objects measured in
the reference corpus; R761's largest delivered picture is 1.4 MP."""
assert assets.MAX_IMAGE_PIXELS > 4515 * 4128
assert assets.MAX_IMAGE_BYTES >= assets.MAX_IMAGE_PIXELS
def test_a_pdf_image_over_the_limit_is_refused_by_code() -> None:
pytest.importorskip("pdfplumber")
dimension = 1 + int(assets.MAX_IMAGE_PIXELS**0.5)
extracted = extract_document("bomb.pdf", _bomb(dimension), assets=True)
assert extracted.images == ()
assert [rejection.code for rejection in extracted.rejected] == ["asset_too_large"]
assert str(dimension) in extracted.rejected[0].reason
def test_a_pdf_image_under_the_limit_is_still_carried() -> None:
"""The boundary from the other side, on the same generator."""
pytest.importorskip("pdfplumber")
extracted = extract_document("small.pdf", _bomb(64), assets=True)
assert [(image.width, image.height) for image in extracted.images] == [(64, 64)]
def test_the_refusal_happens_before_the_stream_is_decompressed() -> None:
"""The limit is read off the DECLARED size, and the order is observable.
The image stream here is CORRUPT (its bytes are not deflate data) while
its declared size is over the bound. Decoding first gives
`asset_pdf_unsupported` ("could not be decoded"); reading the declared
size first gives `asset_too_large`. A check after `get_data()` has already
paid for the bomb it was meant to stop.
"""
pytest.importorskip("pdfplumber")
dimension = 1 + int(assets.MAX_IMAGE_PIXELS**0.5)
document = _bomb(dimension)
payload = zlib.compress(b"\x00" * (dimension * dimension), 9)
corrupt = document.replace(payload, b"\xff" * len(payload))
assert corrupt != document
extracted = extract_document("corrupt.pdf", corrupt, assets=True)
assert [rejection.code for rejection in extracted.rejected] == ["asset_too_large"]
def test_a_data_uri_over_the_limit_is_refused_before_decoding(
monkeypatch: pytest.MonkeyPatch,
) -> None:
monkeypatch.setattr(assets, "MAX_IMAGE_BYTES", 32)
uri = "data:image/png;base64," + "A" * 4096
extracted = extract_document(
"doc.html", f'<html><body><img src="{uri}"></body></html>'.encode(), assets=True
)
assert [rejection.code for rejection in extracted.rejected] == ["asset_too_large"]
def test_encode_png_refuses_the_same_size_on_its_own() -> None:
"""Defence in depth: the encoder does not trust its caller to have checked."""
dimension = 1 + int(assets.MAX_IMAGE_PIXELS**0.5)
with pytest.raises(ExtractionError) as excinfo:
assets.encode_png(dimension, dimension, b"", channels=1, palette=None, alpha=None)
assert excinfo.value.code == "asset_too_large"
# --- the determinism defect PM added to this order --------------------------
def test_an_inline_pdf_image_gets_a_stable_name() -> None:
"""pdfminer names an inline image (`BI ... EI`) from `id()` of a Python
object, so the pointer line changed between two runs of one build -- two
concept files of the reference corpus differed. Measured 2026-09-17."""
pytest.importorskip("pdfplumber")
from llm_ingestion_okf import extract as extract_module
inline = (
b"BT /F1 12 Tf 20 100 Td (t) Tj ET\n"
b"q 10 0 0 10 20 20 cm BI /W 2 /H 2 /CS /G /BPC 8 /F /AHx ID 00112233> EI Q\n"
)
document = _bomb(4, content=inline)
first = extract_document("inline.pdf", document, assets=True)
extract_module._pdf_pages.cache_clear()
second = extract_document("inline.pdf", document, assets=True)
names = [image.name for image in first.images] + [r.name for r in first.rejected]
again = [image.name for image in second.images] + [r.name for r in second.rejected]
assert names == again != []
assert not any(part.isdigit() and len(part) > 6 for name in names for part in name.split("-"))
# --- BLOCKER-1 of the 18.09 review: the bound must bind what the run PAYS ----
#
# `check_size` reads `/Width` and `/Height` out of the image dictionary, which
# is a CLAIM by an untrusted document, and the claim and the cost are two
# independent numbers: `/Length` is the COMPRESSED length and nothing in the
# dictionary states what `get_data()` will return. Measured on `230d1cb` by an
# independent review: a 389 626-byte PDF declaring 1x1 and carrying 400 MB of
# deflated zeros was CARRIED, with no rejection, at 834 MB of peak RSS -- and
# 1,2 GB of zeros at 2 436 MB, linear, about 2 100x the file size. The four
# mutations that suite already kills do not separate declared from actual, so
# they were all green while this stood.
#: What a bounded run of the 400 MB bomb may cost, in bytes of peak RSS.
#: Measured 2026-09-18 on this machine, same commit, same fixture: 892 MB
#: without the bound and 54 MB with it, and the bounded figure barely moves
#: when the stream triples (62 MB at 1,2 GB) because what grows is the
#: COMPRESSED input, which was already in memory. The bar sits between the
#: two, far enough above the bounded run that the interpreter's own footprint
#: on another machine cannot reach it.
PEAK_RSS_BOUND = 256 * 1024 * 1024
#: The stream the bomb inflates to. Over `MAX_IMAGE_BYTES` (256 MiB), so it is
#: refused at the real bound rather than at a monkeypatched one.
BOMB_STREAM_BYTES = 400 * 1024 * 1024
_CHILD = """
import resource, sys
sys.path.insert(0, {tests!r})
from test_asset_limits import _bomb, _zeros_stream, _nested_zeros_stream
from llm_ingestion_okf.extract import extract_document
document = {builder}
extracted = extract_document("bomb.pdf", document, assets=True)
peak = resource.getrusage(resource.RUSAGE_SELF).ru_maxrss
print(
len(document),
len(extracted.images),
",".join(rejection.code for rejection in extracted.rejected) or "-",
peak if sys.platform == "darwin" else peak * 1024,
)
"""
def _run_bomb(total: int, *, links: int = 1) -> tuple[int, int, str, int]:
"""The bomb in its own interpreter, so peak RSS is ITS peak and not the
high-water mark of every test that ran before it. `links` is how many
`FlateDecode` filters the stream is decoded by."""
builder = (
"_bomb(1, payload=_zeros_stream(%d))" % total
if links == 1
else "_bomb(1, payload=_nested_zeros_stream(%d, %d), filters=%r)"
% (total, links, "[" + " ".join(["/FlateDecode"] * links) + "]")
)
completed = subprocess.run(
[sys.executable, "-c", _CHILD.format(tests=str(Path(__file__).parent), builder=builder)],
capture_output=True,
text=True,
check=True,
)
size, carried, codes, peak = completed.stdout.split()
return int(size), int(carried), codes, int(peak)
def test_a_declared_size_of_one_pixel_does_not_licence_an_unbounded_stream() -> None:
"""The review's repro, at the shipped bound: 1x1 declared, 400 MB paid."""
pytest.importorskip("pdfplumber")
size, carried, codes, peak = _run_bomb(BOMB_STREAM_BYTES)
assert size < 2 * 1024 * 1024, "the fixture must stay a small file, or it proves nothing"
assert carried == 0, "a 400 MB stream was carried as a 1x1 picture"
assert codes == "asset_too_large"
assert peak < PEAK_RSS_BOUND, f"peak RSS {peak} bytes for a {size}-byte file"
def test_the_refusal_reads_the_stream_and_not_only_the_declaration() -> None:
"""The mutation the shipped suite could not kill.
An honest 20000x20000 declaration is refused by `check_size` alone, so a
test built on one is green whether or not the actual stream is bounded.
This document declares a size WITHIN the bound, which is the only shape
that separates the two checks.
"""
pytest.importorskip("pdfplumber")
small = zlib.compress(b"\x00" * 64, 9)
within = extract_document("small.pdf", _bomb(8, payload=small), assets=True)
assert [rejection.code for rejection in within.rejected] == [], "the control must be carried"
assert len(within.images) == 1
def test_a_stream_over_the_bound_is_refused_with_a_patched_bound() -> None:
"""The same rule, cheap, so it runs on every machine and every suite."""
pytest.importorskip("pdfplumber")
monkey = pytest.MonkeyPatch()
try:
monkey.setattr(assets, "MAX_IMAGE_BYTES", 4096)
extracted = extract_document(
"bomb.pdf", _bomb(1, payload=zlib.compress(b"\x00" * 1_000_000, 9)), assets=True
)
finally:
monkey.undo()
assert extracted.images == ()
assert [rejection.code for rejection in extracted.rejected] == ["asset_too_large"]
# --- MAJOR of the 18.09 review: a non-positive declaration is not a size -----
def test_a_non_positive_declared_size_is_refused_before_the_stream_is_read() -> None:
"""`-1 * 40_000_000_000` is NEGATIVE, so `pixels > MAX_IMAGE_PIXELS` was
false and `check_size` returned silently; 400 MB was then decompressed and
the refusal came from `encode_png` with `asset_samples_invalid` -- a code
about the sample buffer for a defect in the declaration.
The stream here is CORRUPT, so the order is observable: reading first gives
`asset_pdf_unsupported`, reading the declaration first gives the new code.
"""
pytest.importorskip("pdfplumber")
document = _bomb(4, payload=b"\xff" * 512).replace(
b"/Width 4 /Height 4", b"/Width -1 /Height 40000000000"
)
assert b"/Width -1" in document
extracted = extract_document("negative.pdf", document, assets=True)
assert extracted.images == ()
assert [rejection.code for rejection in extracted.rejected] == ["asset_size_invalid"]
def test_check_size_refuses_every_non_positive_pair_and_keeps_unknown_unknown() -> None:
for width, height in ((-1, 40_000_000_000), (0, 10), (10, 0), (-2, -2)):
with pytest.raises(ExtractionError) as excinfo:
assets.check_size(width, height, name="n")
assert excinfo.value.code == "asset_size_invalid"
# A size the container never declared is UNKNOWN, not invalid: there is no
# number to bound and inventing one would refuse a legitimate picture.
assets.check_size(None, None, name="n")
assets.check_size(None, 10, name="n")
# --- MINOR-3: the bound holds for a file carried verbatim, too ---------------
def _png_header(width: int, height: int) -> bytes:
"""A PNG whose IHDR declares `width` x `height` and whose body is a stub.
`read_image` sniffs and reads the header; it never decodes."""
def chunk(kind: bytes, payload: bytes) -> bytes:
return (
len(payload).to_bytes(4, "big")
+ kind
+ payload
+ zlib.crc32(kind + payload).to_bytes(4, "big")
)
ihdr = width.to_bytes(4, "big") + height.to_bytes(4, "big") + bytes([8, 0, 0, 0, 0])
return b"\x89PNG\r\n\x1a\n" + chunk(b"IHDR", ihdr) + chunk(b"IEND", b"")
def test_an_image_file_over_the_bound_is_refused_although_it_is_never_decoded() -> None:
"""A 7 000 x 7 000 PNG is 49 MP in 47 705 bytes. This package does not
decode a carried file, so it pays nothing -- but writing it into a bundle
hands the consumer the same bomb with `7000x7000 px` printed beside it,
and the README's first sentence says such an image is refused."""
with pytest.raises(ExtractionError) as excinfo:
assets.read_image(_png_header(7000, 7000), name="big.png")
assert excinfo.value.code == "asset_too_large"
def test_an_image_file_under_the_bound_is_still_read() -> None:
image = assets.read_image(_png_header(4515, 4128), name="drawing.png")
assert (image.width, image.height) == (4515, 4128)
# --- MINOR-1 and MINOR-2 of the 18.09 review --------------------------------
def test_a_remote_address_is_never_written_as_a_bare_url() -> None:
"""`inert` was only half true: the address was written TWICE, once in a
code span and once bare, and a GFM/linkify renderer autolinks the bare
one into `<a href="...">`. Measured with `markdown_it('gfm-like')`."""
line = render_missing(REMOTE, reason="the source is off this machine", href=REMOTE)
assert "](" not in line
assert REMOTE in line
for position in range(len(line)):
if line.startswith(REMOTE, position):
assert line[position - 1] == "`" and line[position + len(REMOTE)] == "`", (
f"a bare occurrence of the address at {position}: {line!r}"
)
def test_the_caption_of_a_remote_reference_is_still_stated() -> None:
"""`label` became a dead parameter in 0.10.1, so the alt text or figure
caption of an image the bundle does not carry was DROPPED -- a regression
against 0.10.0 and against this module's own reason for writing the line:
a reader cannot weigh an absence they were never shown."""
line = render_missing(
"p.gif", reason="the source is off this machine", label="Figur 84-1 Tverrprofil", href=None
)
assert "Figur 84-1 Tverrprofil" in line
with_href = render_missing(
REMOTE, reason="the source is off this machine", label="Figur 84-1 Tverrprofil", href=REMOTE
)
assert "Figur 84-1 Tverrprofil" in with_href
# --- BLOCKER of the 18.09 PM checkpoint: the CHAIN, not only its first link --
#
# `_check_inflated` read `filters[0]`, measured that one link, and returned.
# A PDF may decode a stream through a chain (`/Filter [/FlateDecode
# /FlateDecode]`), and the PM's repro measured what that costs on `0f308c1`:
# 1 606 bytes of stream became 835 MB of peak RSS and 2 839 bytes became
# 2 439 MB -- linear, about 860 000x the file size, and 400x worse than the
# single-link bomb the 0.10.1 fix was written for. The image is refused at the
# end by `check_payload`, after the memory has been spent; one 3 KB document
# takes a batch build with it.
#
# The corpora say the chain is not a hypothetical shape. Over the 5 142 image
# objects of the 78 PDFs on this machine (measured 2026-09-18), 596 decode
# through `[/FlateDecode /DCTDecode]`, 580 through `[/FlateDecode
# /ASCII85Decode]` and 16 through `[/ASCII85Decode /FlateDecode]` -- so a rule
# that refuses every chain would cost 1 192 real pictures, and a rule that
# bounds only the first link leaves all 16 of the last group unbounded.
def test_a_chain_of_two_flate_filters_costs_no_more_than_one() -> None:
"""The PM's repro at the shipped bound, in its own interpreter."""
pytest.importorskip("pdfplumber")
size, carried, codes, peak = _run_bomb(BOMB_STREAM_BYTES, links=2)
assert size < 2 * 1024 * 1024, "the fixture must stay a small file, or it proves nothing"
assert carried == 0, "a 400 MB stream was carried as a 1x1 picture"
assert codes == "asset_too_large"
assert peak < PEAK_RSS_BOUND, f"peak RSS {peak} bytes for a {size}-byte file"
def test_a_chain_of_three_flate_filters_costs_no_more_than_one() -> None:
"""A chain this package has never seen -- the bound must not be a list of
the shapes somebody thought of."""
pytest.importorskip("pdfplumber")
size, carried, codes, peak = _run_bomb(BOMB_STREAM_BYTES, links=3)
assert carried == 0
assert codes == "asset_too_large"
assert peak < PEAK_RSS_BOUND, f"peak RSS {peak} bytes for a {size}-byte file"
def test_every_link_of_a_flate_chain_is_measured_with_a_patched_bound() -> None:
"""The same rule, cheap, so it runs on every machine and every suite."""
pytest.importorskip("pdfplumber")
payload = _nested_zeros_stream(1 << 20, 2)
monkey = pytest.MonkeyPatch()
try:
monkey.setattr(assets, "MAX_IMAGE_BYTES", 4096)
extracted = extract_document(
"nested.pdf",
_bomb(1, payload=payload, filters="[/FlateDecode /FlateDecode]"),
assets=True,
)
finally:
monkey.undo()
assert len(payload) < 4096, "the stream itself is under the bound; only its output is over"
assert extracted.images == ()
assert [rejection.code for rejection in extracted.rejected] == ["asset_too_large"]
# WHICH check fired is the whole point: the backstop refuses this document
# too, after the memory is spent, so a test that reads only the code is
# green on the defect. The two refusals say different things.
assert "decompresses to more than" in extracted.rejected[0].reason, (
"refused by the backstop after decoding, not by the bound before it: "
+ extracted.rejected[0].reason
)
def test_a_flate_link_behind_an_ascii85_link_is_measured_too() -> None:
"""`[/ASCII85Decode /FlateDecode]` is 16 real objects of the corpora, and
`filters[0]` is not `FlateDecode`, so the old rule returned without
measuring anything at all."""
pytest.importorskip("pdfplumber")
import base64
payload = base64.a85encode(_zeros_stream(1 << 20), adobe=True)
monkey = pytest.MonkeyPatch()
try:
monkey.setattr(assets, "MAX_IMAGE_BYTES", 4096)
extracted = extract_document(
"a85.pdf",
_bomb(1, payload=payload, filters="[/ASCII85Decode /FlateDecode]"),
assets=True,
)
finally:
monkey.undo()
assert extracted.images == ()
assert [rejection.code for rejection in extracted.rejected] == ["asset_too_large"]
assert "decompresses to more than" in extracted.rejected[0].reason, (
"refused by the backstop after decoding, not by the bound before it: "
+ extracted.rejected[0].reason
)
def test_a_chained_image_within_the_bound_is_still_carried() -> None:
"""The known-positive beside all of them: the two chains the corpora
actually hold must still deliver their picture."""
pytest.importorskip("pdfplumber")
import base64
samples = zlib.compress(b"\x00" * (64 * 64), 9)
for filters, payload in (
("[/ASCII85Decode /FlateDecode]", base64.a85encode(samples, adobe=True)),
("[/FlateDecode]", samples),
):
extracted = extract_document(
"ok.pdf", _bomb(64, payload=payload, filters=filters), assets=True
)
assert [r.code for r in extracted.rejected] == [], filters
assert [(i.width, i.height) for i in extracted.images] == [(64, 64)], filters
def test_a_filter_the_bound_cannot_measure_is_refused_before_it_is_decoded() -> None:
"""`LZWDecode` and `RunLengthDecode` expand by an amount pdfminer will only
reveal by producing the whole output, so there is no measuring them a chunk
at a time. They are refused with a code BEFORE the decode, which is the
order the stream here makes observable: its bytes are not valid input for
either filter, so decoding first gives `asset_pdf_unsupported`.
"""
pytest.importorskip("pdfplumber")
for filters in ("/LZWDecode", "/RunLengthDecode", "[/FlateDecode /LZWDecode]"):
extracted = extract_document(
"unknown.pdf", _bomb(4, payload=b"\xff" * 512, filters=filters), assets=True
)
assert extracted.images == ()
assert [r.code for r in extracted.rejected] == ["asset_pdf_unbounded"], filters
def test_the_filters_this_package_bounds_are_the_ones_the_corpora_hold() -> None:
"""The published claim, as a test: these names are what the close-out
message and the four documentation surfaces say are carried."""
from llm_ingestion_okf import extract as extract_module
carried = extract_module.bounded_pdf_filters()
assert carried == {
"FlateDecode",
"ASCII85Decode",
"ASCIIHexDecode",
"DCTDecode",
"JPXDecode",
"JBIG2Decode",
}
def test_an_encrypted_stream_is_deciphered_and_then_bounded() -> None:
"""`stream.decipher is not None` returned without measuring, so a document
that declares encryption was a way past the bound. Deciphering does not
change a stream's length, so this package does what pdfminer's own
`decode()` does -- decipher first, then measure the filters.
"""
pytest.importorskip("pdfplumber")
from pdfminer.pdftypes import PDFStream
from pdfminer.psparser import LIT
from llm_ingestion_okf import extract as extract_module
def rot(objid: int, genno: int, data: bytes, attrs: dict[str, object]) -> bytes:
return bytes(byte ^ 0x5A for byte in data)
raw = _zeros_stream(1 << 20)
stream = PDFStream(
{"Width": 1, "Height": 1, "BitsPerComponent": 8, "Filter": LIT("FlateDecode")},
rot(0, 0, raw, {}),
decipher=rot,
)
stream.set_objid(1, 0)
monkey = pytest.MonkeyPatch()
try:
monkey.setattr(assets, "MAX_IMAGE_BYTES", 4096)
with pytest.raises(ExtractionError) as excinfo:
extract_module._check_stream_cost(stream, "encrypted")
finally:
monkey.undo()
assert excinfo.value.code == "asset_too_large"
# --- MAJOR of the 18.09 PM checkpoint: the backstop is covered ---------------
def test_the_backstop_refuses_a_payload_the_stream_bound_never_saw() -> None:
"""`check_payload(len(data))` after `get_data()` is the counted refusal the
docstrings, the README, the CHANGELOG and CLAUDE.md all point at -- and
deleting exactly that line passed the whole suite (2 132 tests) on
`0f308c1`, because every other test reaches a bound that fires earlier.
The path that reaches it is a stream pdfminer has ALREADY decoded: `decode()`
sets `rawdata` to `None`, so there is no raw stream left to measure and the
memory is spent before this package is asked anything. The picture is then
dropped by count rather than by bound, which is the weaker guarantee the
documents describe -- and nothing held it.
"""
pytest.importorskip("pdfplumber")
from pdfminer.pdftypes import PDFStream
from pdfminer.psparser import LIT
from llm_ingestion_okf import extract as extract_module
stream = PDFStream(
{"Width": 8, "Height": 8, "BitsPerComponent": 8, "Filter": LIT("FlateDecode")},
zlib.compress(b"\x00" * 4096, 9),
)
stream.set_objid(1, 0)
assert len(stream.get_data()) == 4096
assert stream.get_rawdata() is None, (
"the stream must be decoded already, or this proves nothing"
)
monkey = pytest.MonkeyPatch()
try:
monkey.setattr(assets, "MAX_IMAGE_BYTES", 1024)
with pytest.raises(ExtractionError) as excinfo:
extract_module._pdf_image(stream, "decoded")
finally:
monkey.undo()
assert excinfo.value.code == "asset_too_large", (
"without the backstop this falls through to the encoder and is reported "
"as a defect of the sample buffer"
)
def test_a_decoded_stream_under_the_bound_is_still_read() -> None:
"""The known-positive for the test above: the backstop must not be a rule
that refuses every already-decoded stream."""
pytest.importorskip("pdfplumber")
from pdfminer.pdftypes import PDFStream
from pdfminer.psparser import LIT
from llm_ingestion_okf import extract as extract_module
stream = PDFStream(
{
"Width": 8,
"Height": 8,
"BitsPerComponent": 8,
"ColorSpace": LIT("DeviceGray"),
"Filter": LIT("FlateDecode"),
},
zlib.compress(b"\x00" * 64, 9),
)
stream.set_objid(1, 0)
stream.get_data()
image = extract_module._pdf_image(stream, "decoded")
assert (image.width, image.height) == (8, 8)