Files
github-spec-kit/tests/test_shared_infra_integrity.py
Zied Jlassi b042d2a843 feat(extensions): verify catalog archive sha256 before install (#3080)
* feat(extensions): verify catalog archive sha256 before install

Extension and preset archives were downloaded over HTTPS and unpacked
(with Zip-Slip protection) but their bytes were never checked against a
known digest. Trust rested entirely on TLS and the integrity of the
release host, so a tampered or swapped archive from a compromised
third-party release would be installed silently. Maintainers do not audit
extension code, so consumer-side integrity is the only available defence.

Catalog entries may now pin an optional `sha256` digest. When present, the
downloaded archive is verified before it is written to disk and installed;
a mismatch aborts with a clear error. Entries without `sha256` keep
working unchanged (a DEBUG line records that the download was unverified),
so the change is backwards compatible. The check runs on both download
paths (extensions and presets) via a single shared helper so the two stay
in parity.

- Add `verify_archive_sha256` helper in shared_infra (digest match,
  `sha256:` prefix, case-insensitive; DEBUG log when no digest declared)
- Enforce it in ExtensionCatalog.download_extension and
  PresetCatalog.download_pack, before the archive is written to disk
- Document the optional `sha256` field in the publishing guides
- Tests: helper unit tests + matching/mismatch/no-digest on both paths

Signed-off-by: Zied Jlassi <6190550+zied-jlassi@users.noreply.github.com>
Assisted-by: AI

* fix(extensions): harden sha256 parsing and tidy download test mocks

Follow-up to the review on #3080:

- shared_infra.verify_archive_sha256: strip only a literal `sha256:`
  algorithm prefix (case-insensitive) instead of `split(':', 1)[-1]`,
  which silently dropped any prefix — so `md5:<64-hex>` was accepted as
  if it were a valid SHA-256. Validate that the declared value is exactly
  64 hex characters and raise a clear error otherwise, and compare with
  `hmac.compare_digest` for a constant-time check. Add tests covering a
  malformed digest and a non-`sha256:` prefix (both previously accepted).
- Download test helpers: configure the context-manager mock via
  `__enter__.return_value`/`__exit__.return_value` rather than assigning a
  `lambda s: s`, which is clearer and independent of the invocation arity.

Assisted-by: AI
Signed-off-by: Zied Jlassi (Architect AI) <6190550+zied-jlassi@users.noreply.github.com>

* fix(extensions): reject a declared-but-empty sha256 instead of skipping verification

verify_archive_sha256 skipped on any falsy expected value, so a present-but-empty digest (e.g. sha256: "" reached via ...get("sha256")) silently disabled the integrity check instead of surfacing the authoring error. Guard on expected is None so only an absent digest skips; blank/whitespace/bare-prefix values fall through to the 64-hex validation and are rejected. Adds a regression test.

Signed-off-by: Zied Jlassi <6190550+zied-jlassi@users.noreply.github.com>

* docs(shared_infra): clarify _SHA256_HEX_RE accepts and normalizes uppercase

The comment described the regex as matching '64 lowercase' hex characters,
but verify_archive_sha256 lowercases the declared value (raw.lower()) before
matching, so an uppercase digest is accepted and normalized rather than
rejected. Clarify the comment to avoid misleading future readers.

Addresses Copilot review feedback on shared_infra.py.

Signed-off-by: Zied Jlassi <6190550+zied-jlassi@users.noreply.github.com>

* test(presets): cover the no-sha256 backwards-compatible path

Address Copilot review: download_pack's optional sha256 verification was
tested for match/mismatch but not the backwards-compatible path where a
catalog entry has no sha256 (pack_info.get("sha256") is None). Add a
no-sha256 test mirroring the extensions coverage so the helper never
silently becomes mandatory for presets.

Signed-off-by: Zied Jlassi <6190550+zied-jlassi@users.noreply.github.com>

---------

Signed-off-by: Zied Jlassi <6190550+zied-jlassi@users.noreply.github.com>
Signed-off-by: Zied Jlassi (Architect AI) <6190550+zied-jlassi@users.noreply.github.com>
2026-06-24 14:52:24 -05:00

102 lines
3.7 KiB
Python

"""Unit tests for the shared archive-integrity helper.
These exercise ``verify_archive_sha256`` directly (independently of the
extension/preset download paths that call it) so the digest-matching,
mismatch, normalisation and "no digest declared" behaviours are pinned in
one place.
"""
from __future__ import annotations
import hashlib
import logging
import pytest
from specify_cli.shared_infra import verify_archive_sha256
class _BoomError(Exception):
"""Sentinel error type used to assert the helper raises ``error_cls``."""
def test_matching_digest_passes():
"""A digest that matches the data returns without raising."""
data = b"hello-archive"
digest = hashlib.sha256(data).hexdigest()
verify_archive_sha256(data, digest, "thing", _BoomError)
def test_mismatch_raises_error_cls():
"""A non-matching digest raises the caller-supplied error type."""
with pytest.raises(_BoomError, match="[Ii]ntegrity"):
verify_archive_sha256(b"data", "0" * 64, "thing", _BoomError)
def test_sha256_prefix_is_accepted():
"""A ``sha256:`` prefix on the expected digest is tolerated."""
data = b"prefixed"
digest = hashlib.sha256(data).hexdigest()
verify_archive_sha256(data, f"sha256:{digest}", "thing", _BoomError)
def test_comparison_is_case_insensitive():
"""An upper-cased expected digest still matches the lower-case actual."""
data = b"casing"
digest = hashlib.sha256(data).hexdigest().upper()
verify_archive_sha256(data, digest, "thing", _BoomError)
def test_malformed_digest_is_rejected():
"""A declared digest that is not 64 hex chars is rejected up front.
A too-short, too-long, or non-hex value is an authoring/catalog error and
must surface clearly instead of being treated as a digest that simply does
not match the archive.
"""
for bad in ("deadbeef", "z" * 64, "0" * 63, "0" * 65):
with pytest.raises(_BoomError, match="[Ii]nvalid sha256"):
verify_archive_sha256(b"data", bad, "thing", _BoomError)
def test_non_sha256_prefix_is_not_silently_stripped():
"""Only a literal ``sha256:`` prefix is stripped.
A different algorithm prefix (e.g. ``md5:``) must not be silently dropped
and accepted as if the remaining characters were a valid SHA-256 digest;
the value is rejected as malformed.
"""
data = b"prefixed"
digest = hashlib.sha256(data).hexdigest()
with pytest.raises(_BoomError, match="[Ii]nvalid sha256"):
verify_archive_sha256(data, f"md5:{digest}", "thing", _BoomError)
def test_absent_digest_skips_and_logs_debug(caplog):
"""When no digest is declared the helper returns and logs at DEBUG.
Installs stay backwards compatible (no error, no user-facing warning),
but the unverified download leaves an audit trail for operators who opt
into debug logging.
"""
with caplog.at_level(logging.DEBUG, logger="specify_cli.shared_infra"):
verify_archive_sha256(b"data", None, "thing", _BoomError)
assert any(
"not verified" in r.getMessage() and "thing" in r.getMessage()
for r in caplog.records
)
def test_blank_declared_digest_is_rejected():
"""A present-but-empty ``sha256`` is an authoring error, not an opt-out.
Catalog entries reach the helper via ``...get("sha256")``; a blank value
(``""``, whitespace, or a bare ``sha256:`` prefix) means the digest was
declared but left empty. It must surface as a malformed digest rather than
silently disabling the integrity check, which a bare ``if not expected``
guard would have done.
"""
for blank in ("", " ", "sha256:"):
with pytest.raises(_BoomError, match="[Ii]nvalid sha256"):
verify_archive_sha256(b"data", blank, "thing", _BoomError)