Commit `5a9365de64`

5a9365de648fbebc60be14161e394e959bdb7e5c

Verified · cmc

cmc <hello@cleberg.net> · 2026-08-06 08:07 UTC

feat: tamper-evident seals and chain of custody for evidence

evidence-seal writes a canonical manifest.json over a directory: per-file
SHA-256, a Merkle root fingerprint, provenance metadata, and a self-derived id.
verify recomputes and names any modified/added/removed file; a 'previous' link
chains sequential seals into an append-only history that catches reordering or a
spliced-out entry. Optional ed25519 signing adds signer attribution.

- hashing: streaming file SHA-256 and a path-bound Merkle root
- manifest: build/verify/chain, canonical id, ignore globs recorded for verify
- signing: lazy-loaded ed25519 (cryptography extra); core is stdlib-only
- cli: seal/verify/chain/keygen/sign with 0/1/2 exit-code contract
- 28 tests, ruff clean

Layout: unified · split

.gitignore added +16

		@@ -0,0 +1,16 @@
	1	.venv
	2	venv
	3
	4	# Python
	5	__pycache__/
	6	**/__pycache__/
	7	*.py[cod]
	8	*.egg-info/
	9	.pytest_cache/
	10	.ruff_cache/
	11	build/
	12	dist/
	13
	14	# Local keys and manifests produced by ad-hoc runs
	15	*.pem
	16	/scratch/

CODEOWNERS added +1

		@@ -0,0 +1 @@
	1	* @ccleberg @ekraai2

LICENSE added +674

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	520
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	522	the scope of its coverage, prohibits the exercise of, or is
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	527	to the third party based on the extent of your activity of conveying
	528	the work, and under which the third party grants, to any of the
	529	parties who would receive the covered work from you, a discriminatory
	530	patent license (a) in connection with copies of the covered work
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	533	contain the covered work, unless you entered into that arrangement,
	534	or that patent license was granted, prior to 28 March 2007.
	535
	536	Nothing in this License shall be construed as excluding or limiting
	537	any implied license or other defenses to infringement that may
	538	otherwise be available to you under applicable patent law.
	539
	540	12. No Surrender of Others' Freedom.
	541
	542	If conditions are imposed on you (whether by court order, agreement or
	543	otherwise) that contradict the conditions of this License, they do not
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	545	covered work so as to satisfy simultaneously your obligations under this
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	547	not convey it at all. For example, if you agree to terms that obligate you
	548	to collect a royalty for further conveying from those to whom you convey
	549	the Program, the only way you could satisfy both those terms and this
	550	License would be to refrain entirely from conveying the Program.
	551
	552	13. Use with the GNU Affero General Public License.
	553
	554	Notwithstanding any other provision of this License, you have
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	559	but the special requirements of the GNU Affero General Public License,
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	561	combination as such.
	562
	563	14. Revised Versions of this License.
	564
	565	The Free Software Foundation may publish revised and/or new versions of
	566	the GNU General Public License from time to time. Such new versions will
	567	be similar in spirit to the present version, but may differ in detail to
	568	address new problems or concerns.
	569
	570	Each version is given a distinguishing version number. If the
	571	Program specifies that a certain numbered version of the GNU General
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	573	option of following the terms and conditions either of that numbered
	574	version or of any later version published by the Free Software
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	576	GNU General Public License, you may choose any version ever published
	577	by the Free Software Foundation.
	578
	579	If the Program specifies that a proxy can decide which future
	580	versions of the GNU General Public License can be used, that proxy's
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	585	permissions. However, no additional obligations are imposed on any
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	587	later version.
	588
	589	15. Disclaimer of Warranty.
	590
	591	THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
	592	APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
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	610	SUCH DAMAGES.
	611
	612	17. Interpretation of Sections 15 and 16.
	613
	614	If the disclaimer of warranty and limitation of liability provided
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	617	an absolute waiver of all civil liability in connection with the
	618	Program, unless a warranty or assumption of liability accompanies a
	619	copy of the Program in return for a fee.
	620
	621	END OF TERMS AND CONDITIONS
	622
	623	How to Apply These Terms to Your New Programs
	624
	625	If you develop a new program, and you want it to be of the greatest
	626	possible use to the public, the best way to achieve this is to make it
	627	free software which everyone can redistribute and change under these terms.
	628
	629	To do so, attach the following notices to the program. It is safest
	630	to attach them to the start of each source file to most effectively
	631	state the exclusion of warranty; and each file should have at least
	632	the "copyright" line and a pointer to where the full notice is found.
	633
	634	<one line to give the program's name and a brief idea of what it does.>
	635	Copyright (C) <year> <name of author>
	636
	637	This program is free software: you can redistribute it and/or modify
	638	it under the terms of the GNU General Public License as published by
	639	the Free Software Foundation, either version 3 of the License, or
	640	(at your option) any later version.
	641
	642	This program is distributed in the hope that it will be useful,
	643	but WITHOUT ANY WARRANTY; without even the implied warranty of
	644	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	645	GNU General Public License for more details.
	646
	647	You should have received a copy of the GNU General Public License
	648	along with this program. If not, see <https://www.gnu.org/licenses/>.
	649
	650	Also add information on how to contact you by electronic and paper mail.
	651
	652	If the program does terminal interaction, make it output a short
	653	notice like this when it starts in an interactive mode:
	654
	655	<program> Copyright (C) <year> <name of author>
	656	This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
	657	This is free software, and you are welcome to redistribute it
	658	under certain conditions; type `show c' for details.
	659
	660	The hypothetical commands `show w' and `show c' should show the appropriate
	661	parts of the General Public License. Of course, your program's commands
	662	might be different; for a GUI interface, you would use an "about box".
	663
	664	You should also get your employer (if you work as a programmer) or school,
	665	if any, to sign a "copyright disclaimer" for the program, if necessary.
	666	For more information on this, and how to apply and follow the GNU GPL, see
	667	<https://www.gnu.org/licenses/>.
	668
	669	The GNU General Public License does not permit incorporating your program
	670	into proprietary programs. If your program is a subroutine library, you
	671	may consider it more useful to permit linking proprietary applications with
	672	the library. If this is what you want to do, use the GNU Lesser General
	673	Public License instead of this License. But first, please read
	674	<https://www.gnu.org/licenses/why-not-lgpl.html>.

README.md added +131

		@@ -0,0 +1,131 @@
	1	# evidence-seal
	2
	3	[![License: GPL v3](https://img.shields.io/badge/License-GPLv3-blue.svg)](LICENSE)
	4	[![Python](https://img.shields.io/badge/python-3.10%2B-blue.svg)]()
	5
	6	Tamper-evident seals and chain of custody for audit evidence packages.
	7
	8	Every Audit Labs tool assumes the evidence it handles is authentic. `evidence-seal`
	9	is what makes that assumption checkable. Point it at a directory of evidence — an
	10	[audit-tools](https://github.com/audit-labs/audit-tools) package, a folder of
	11	exported screenshots, anything — and it writes a `manifest.json` that pins every
	12	file's SHA-256 into a single Merkle fingerprint. Later, `verify` proves the
	13	directory is byte-for-byte what was sealed, and names anything that changed.
	14
	15	- Integrity — detect any modified, added, or removed file.
	16	- Chain of custody — link sequential seals so a series of dated packages
	17	forms an append-only history; reordering or removing one is detectable.
	18	- Attribution (optional) — sign a manifest with an ed25519 key so a named
	19	party attests "I collected this," not just "it is unchanged."
	20
	21	The core (`seal`, `verify`, `chain`) is pure standard library — no
	22	dependencies. Signing needs `cryptography` (`pip install evidence-seal[sign]`).
	23
	24	## Install
	25
	26	```bash
	27	git clone https://github.com/audit-labs/evidence-seal
	28	cd evidence-seal
	29	python -m venv .venv && source .venv/bin/activate
	30	pip install -e ".[sign]" # drop [sign] for the zero-dependency core
	31	```
	32
	33	## Usage
	34
	35	```bash
	36	# Seal a package (manifest written to <dir>.manifest.json alongside it)
	37	evidence-seal seal ./output/aws_audit_prod_2026-01-01 \
	38	--meta engagement=ACME-2026 --meta collector="Christian Cleberg"
	39
	40	# Later, prove nothing changed
	41	evidence-seal verify ./output/aws_audit_prod_2026-01-01
	42	# -> intact — 8 files match the seal (exit 0)
	43	# -> TAMPERED … MODIFIED iam_users.csv (exit 1)
	44	```
	45
	46	### Chain of custody
	47
	48	Seal each new package against the previous manifest to build a verifiable
	49	timeline:
	50
	51	```bash
	52	evidence-seal seal ./pkg_jan --out seals/jan.json
	53	evidence-seal seal ./pkg_feb --out seals/feb.json --prev seals/jan.json
	54	evidence-seal seal ./pkg_mar --out seals/mar.json --prev seals/feb.json
	55
	56	evidence-seal chain seals/jan.json seals/feb.json seals/mar.json
	57	# -> chain intact — 3 seals link correctly
	58	```
	59
	60	Each manifest's `id` is the hash of its own canonical contents, and `previous`
	61	holds the prior manifest's id — so a broken, reordered, or spliced-out link is
	62	caught.
	63
	64	### Signing (attribution)
	65
	66	```bash
	67	evidence-seal keygen --private acme.key --public acme.pub # once
	68	evidence-seal seal ./pkg --sign acme.key # seal + sign
	69	evidence-seal verify ./pkg --pubkey acme.pub # require this signer
	70	```
	71
	72	Without `--pubkey`, a present signature is still checked for validity; with it,
	73	the signer's key must also match, proving identity and not just integrity.
	74
	75	## The manifest
	76
	77	Canonical JSON, sorted keys — diff-friendly and reproducible:
	78
	79	```json
	80	{
	81	"algorithm": "sha256",
	82	"created_at": "2026-08-06T08:06:05Z",
	83	"subject": "aws_audit_prod_2026-01-01",
	84	"previous": null,
	85	"metadata": { "collector": "Christian Cleberg", "engagement": "ACME-2026" },
	86	"root": "23fdf7eb…",
	87	"file_count": 8,
	88	"files": [ { "path": "iam_users.csv", "sha256": "309b0e45…", "bytes": 412 } ],
	89	"id": "08b846a0…",
	90	"signature": { "algorithm": "ed25519", "public_key": "1bea5f1d…", "value": "2d7c2d63…" }
	91	}
	92	```
	93
	94	- `root` — Merkle root over all `(path, sha256)` leaves; one value that
	95	changes if any file, name, or byte changes.
	96	- `id` — SHA-256 of the manifest's canonical form (excluding `id` and
	97	`signature`); makes it self-verifying and chainable.
	98	- `ignore` — glob patterns skipped at seal time; `verify` reuses them so it
	99	never false-flags an intentionally excluded file.
	100
	101	## Exit codes
	102
	103	\| Code \| Meaning \|
	104	\| --- \| --- \|
	105	\| `0` \| Intact / valid. \|
	106	\| `1` \| Tamper detected, chain broken, or signature invalid. \|
	107	\| `2` \| Usage error (missing directory, bad `--meta`, missing `cryptography`). \|
	108
	109	Fail a pipeline on `1`; treat `2` as a misconfiguration to fix.
	110
	111	## Threat model
	112
	113	`evidence-seal` proves a directory matches a manifest, and (when signed) who
	114	produced that manifest. It does not prove when something was sealed beyond
	115	the self-reported `created_at`, and an unsigned manifest can be regenerated by
	116	anyone with the files. For strong "sealed at time T by party P" guarantees,
	117	sign the manifest and retain the public key out of band; optionally submit the
	118	manifest `id` to an external timestamping authority. Private keys are written
	119	unencrypted — store them accordingly.
	120
	121	## Development
	122
	123	```bash
	124	pip install -e ".[dev]"
	125	pytest
	126	ruff check .
	127	```
	128
	129	## License
	130
	131	GPL-3.0-or-later. See [LICENSE](LICENSE).

conftest.py added +6

		@@ -0,0 +1,6 @@
	1	"""Pin the project root on sys.path so ``import evidence_seal`` works in tests."""
	2
	3	import sys
	4	from pathlib import Path
	5
	6	sys.path.insert(0, str(Path(__file__).parent))

evidence_seal/__init__.py added +8

		@@ -0,0 +1,8 @@
	1	"""evidence-seal — tamper-evident seals for audit evidence packages."""
	2
	3	__version__ = "0.1.0"
	4
	5	# Hash algorithm and manifest format version. Bump MANIFEST_VERSION only on a
	6	# breaking change to the manifest schema so verify can refuse the unknown.
	7	ALGORITHM = "sha256"
	8	MANIFEST_VERSION = 1

evidence_seal/__main__.py added +6

		@@ -0,0 +1,6 @@
	1	"""Enable ``python -m evidence_seal``."""
	2
	3	from .cli import main
	4
	5	if __name__ == "__main__":
	6	raise SystemExit(main())

evidence_seal/cli.py added +226

		@@ -0,0 +1,226 @@
	1	"""Command-line interface for evidence-seal."""
	2
	3	from __future__ import annotations
	4
	5	import argparse
	6	import sys
	7	from pathlib import Path
	8
	9	from . import __version__
	10	from .manifest import (
	11	build_manifest,
	12	load_manifest,
	13	verify_chain,
	14	verify_manifest,
	15	write_manifest,
	16	)
	17
	18	# Exit codes: 0 = intact/valid, 1 = tamper/verification failure, 2 = usage error.
	19	OK, FAILED, USAGE = 0, 1, 2
	20
	21
	22	def _default_manifest_path(directory: Path) -> Path:
	23	return directory.parent / f"{directory.name}.manifest.json"
	24
	25
	26	def _manifest_exclude(directory: Path, manifest_path: Path) -> set[str]:
	27	"""If the manifest lives inside the sealed dir, it must not seal itself."""
	28	try:
	29	return {manifest_path.resolve().relative_to(directory.resolve()).as_posix()}
	30	except ValueError:
	31	return set()
	32
	33
	34	def _parse_meta(pairs: list[str]) -> dict:
	35	meta = {}
	36	for pair in pairs or []:
	37	if "=" not in pair:
	38	raise ValueError(f"metadata must be key=value, got {pair!r}")
	39	key, value = pair.split("=", 1)
	40	meta[key.strip()] = value.strip()
	41	return meta
	42
	43
	44	def _cmd_seal(args) -> int:
	45	directory = Path(args.directory)
	46	manifest_path = Path(args.out) if args.out else _default_manifest_path(directory)
	47
	48	previous = None
	49	if args.prev:
	50	previous = load_manifest(args.prev).get("id")
	51
	52	try:
	53	manifest = build_manifest(
	54	directory,
	55	metadata=_parse_meta(args.meta),
	56	previous=previous,
	57	ignore=args.ignore,
	58	exclude=_manifest_exclude(directory, manifest_path),
	59	)
	60	except (FileNotFoundError, ValueError) as exc:
	61	print(f"error: {exc}", file=sys.stderr)
	62	return USAGE
	63
	64	if args.sign:
	65	from .signing import sign_manifest
	66
	67	try:
	68	manifest = sign_manifest(manifest, args.sign)
	69	except (RuntimeError, OSError) as exc:
	70	print(f"error: {exc}", file=sys.stderr)
	71	return USAGE
	72
	73	write_manifest(manifest, manifest_path)
	74	signed = " (signed)" if "signature" in manifest else ""
	75	print(f"sealed {manifest['file_count']} files{signed}", file=sys.stderr)
	76	print(f" root {manifest['root']}", file=sys.stderr)
	77	print(f" id {manifest['id']}", file=sys.stderr)
	78	print(f" -> {manifest_path}", file=sys.stderr)
	79	return OK
	80
	81
	82	def _cmd_verify(args) -> int:
	83	directory = Path(args.directory)
	84	manifest_path = Path(args.manifest) if args.manifest else _default_manifest_path(directory)
	85	try:
	86	manifest = load_manifest(manifest_path)
	87	except (FileNotFoundError, ValueError) as exc:
	88	print(f"error: cannot read manifest: {exc}", file=sys.stderr)
	89	return USAGE
	90
	91	result = verify_manifest(
	92	directory,
	93	manifest,
	94	ignore=manifest.get("ignore"),
	95	exclude=_manifest_exclude(directory, manifest_path),
	96	)
	97
	98	for path in result.modified:
	99	print(f" MODIFIED {path}")
	100	for path in result.added:
	101	print(f" ADDED {path}")
	102	for path in result.removed:
	103	print(f" REMOVED {path}")
	104	if not result.id_ok:
	105	print(" MANIFEST id does not re-derive — the manifest itself was altered")
	106	if not result.root_ok:
	107	print(" MANIFEST Merkle root does not match the file list")
	108
	109	status = OK
	110	if not result.intact:
	111	status = FAILED
	112
	113	# Verify a signature when present, or when the caller supplied a key to trust.
	114	if manifest.get("signature") or args.pubkey:
	115	sig_ok = _verify_sig_cli(manifest, args.pubkey)
	116	if not sig_ok:
	117	status = FAILED
	118
	119	if status == OK:
	120	print(f"intact — {result.checked} files match the seal")
	121	else:
	122	print("TAMPERED — the directory does not match its seal", file=sys.stderr)
	123	return status
	124
	125
	126	def _verify_sig_cli(manifest: dict, pubkey_path: str \| None) -> bool:
	127	from .signing import load_public_hex, verify_signature
	128
	129	expected = load_public_hex(pubkey_path) if pubkey_path else None
	130	ok, message = verify_signature(manifest, expected)
	131	print(f" signature {'OK' if ok else 'FAIL'}: {message}")
	132	return ok
	133
	134
	135	def _cmd_chain(args) -> int:
	136	try:
	137	manifests = [load_manifest(p) for p in args.manifests]
	138	except (FileNotFoundError, ValueError) as exc:
	139	print(f"error: cannot read manifest: {exc}", file=sys.stderr)
	140	return USAGE
	141
	142	result = verify_chain(manifests)
	143	if result.ok:
	144	print(f"chain intact — {result.length} seals link correctly")
	145	return OK
	146	where = "" if result.broken_at is None else f" at position {result.broken_at}"
	147	print(f"CHAIN BROKEN{where}: {result.reason}", file=sys.stderr)
	148	return FAILED
	149
	150
	151	def _cmd_keygen(args) -> int:
	152	from .signing import generate_keypair
	153
	154	try:
	155	generate_keypair(args.private, args.public)
	156	except (RuntimeError, OSError) as exc:
	157	print(f"error: {exc}", file=sys.stderr)
	158	return USAGE
	159	print(f"wrote private key {args.private}", file=sys.stderr)
	160	print(f"wrote public key {args.public}", file=sys.stderr)
	161	return OK
	162
	163
	164	def _cmd_sign(args) -> int:
	165	from .signing import sign_manifest
	166
	167	try:
	168	manifest = load_manifest(args.manifest)
	169	signed = sign_manifest(manifest, args.key)
	170	except (RuntimeError, FileNotFoundError, ValueError, OSError) as exc:
	171	print(f"error: {exc}", file=sys.stderr)
	172	return USAGE
	173	write_manifest(signed, args.out or args.manifest)
	174	print(f"signed {args.out or args.manifest}", file=sys.stderr)
	175	return OK
	176
	177
	178	def _build_parser() -> argparse.ArgumentParser:
	179	parser = argparse.ArgumentParser(
	180	prog="evidence-seal",
	181	description="Tamper-evident seals for audit evidence packages.",
	182	)
	183	parser.add_argument("--version", action="version", version=f"evidence-seal {__version__}")
	184	sub = parser.add_subparsers(dest="command", required=True)
	185
	186	p_seal = sub.add_parser("seal", help="seal a directory into a manifest")
	187	p_seal.add_argument("directory")
	188	p_seal.add_argument("--out", help="manifest path (default: <dir>.manifest.json alongside)")
	189	p_seal.add_argument("--prev", help="prior manifest to chain from (records its id as previous)")
	190	p_seal.add_argument("--meta", action="append", metavar="KEY=VALUE", help="provenance metadata")
	191	p_seal.add_argument("--ignore", action="append", metavar="GLOB", help="skip matching paths")
	192	p_seal.add_argument("--sign", metavar="PRIVATE_KEY", help="also sign with an ed25519 key")
	193	p_seal.set_defaults(func=_cmd_seal)
	194
	195	p_verify = sub.add_parser("verify", help="verify a directory against its manifest")
	196	p_verify.add_argument("directory")
	197	p_verify.add_argument("--manifest", help="manifest path (default: <dir>.manifest.json)")
	198	p_verify.add_argument("--pubkey", metavar="PEM", help="require a signature by this public key")
	199	p_verify.set_defaults(func=_cmd_verify)
	200
	201	p_chain = sub.add_parser("chain", help="verify manifests link oldest -> newest")
	202	p_chain.add_argument("manifests", nargs="+", help="manifest files, oldest first")
	203	p_chain.set_defaults(func=_cmd_chain)
	204
	205	p_keygen = sub.add_parser("keygen", help="generate an ed25519 keypair")
	206	p_keygen.add_argument("--private", default="evidence-seal.key")
	207	p_keygen.add_argument("--public", default="evidence-seal.pub")
	208	p_keygen.set_defaults(func=_cmd_keygen)
	209
	210	p_sign = sub.add_parser("sign", help="sign an existing manifest")
	211	p_sign.add_argument("manifest")
	212	p_sign.add_argument("--key", required=True, metavar="PRIVATE_KEY")
	213	p_sign.add_argument("--out", help="write here instead of overwriting the manifest")
	214	p_sign.set_defaults(func=_cmd_sign)
	215
	216	return parser
	217
	218
	219	def main(argv: list[str] \| None = None) -> int:
	220	parser = _build_parser()
	221	args = parser.parse_args(argv if argv is not None else sys.argv[1:])
	222	return args.func(args)
	223
	224
	225	if __name__ == "__main__":
	226	raise SystemExit(main())

evidence_seal/hashing.py added +54

		@@ -0,0 +1,54 @@
	1	"""File hashing and a Merkle root over a set of files.
	2
	3	The Merkle root condenses a whole package into one hash. Two packages with the
	4	same root are byte-identical in content and layout; any change to any file — or
	5	to the set of files — changes the root.
	6	"""
	7
	8	from __future__ import annotations
	9
	10	import hashlib
	11	from pathlib import Path
	12
	13	_CHUNK = 1 << 20 # 1 MiB streaming reads keep memory flat on large evidence
	14
	15
	16	def hash_file(path: str \| Path) -> str:
	17	"""Return the SHA-256 hex digest of a file, read in streaming chunks."""
	18	digest = hashlib.sha256()
	19	with Path(path).open("rb") as handle:
	20	for chunk in iter(lambda: handle.read(_CHUNK), b""):
	21	digest.update(chunk)
	22	return digest.hexdigest()
	23
	24
	25	def hash_bytes(data: bytes) -> str:
	26	"""Return the SHA-256 hex digest of a bytes object."""
	27	return hashlib.sha256(data).hexdigest()
	28
	29
	30	def _leaf(path: str, file_hash: str) -> str:
	31	# Bind the path into the leaf so renaming a file changes the root even when
	32	# its contents are unchanged. A domain prefix separates leaves from nodes.
	33	return hashlib.sha256(f"leaf:{path}\x00{file_hash}".encode()).hexdigest()
	34
	35
	36	def _pair(left: str, right: str) -> str:
	37	return hashlib.sha256(f"node:{left}{right}".encode()).hexdigest()
	38
	39
	40	def merkle_root(entries: dict[str, str]) -> str:
	41	"""Compute a Merkle root from a ``{path: file_hash}`` mapping.
	42
	43	Leaves are ordered by path so the root is deterministic regardless of
	44	filesystem iteration order. An empty package has a well-defined empty root.
	45	"""
	46	if not entries:
	47	return hashlib.sha256(b"empty").hexdigest()
	48
	49	level = [_leaf(path, file_hash) for path, file_hash in sorted(entries.items())]
	50	while len(level) > 1:
	51	if len(level) % 2:
	52	level.append(level[-1]) # duplicate the last node on an odd level
	53	level = [_pair(level[i], level[i + 1]) for i in range(0, len(level), 2)]
	54	return level[0]

evidence_seal/manifest.py added +191

		@@ -0,0 +1,191 @@
	1	"""Build, load, and verify evidence manifests, and verify seal chains.
	2
	3	A manifest is a JSON object describing a sealed directory: every file's SHA-256,
	4	a Merkle ``root`` over them, provenance metadata, and a ``previous`` link to an
	5	earlier manifest's id. Its own ``id`` is the SHA-256 of its canonical form
	6	(excluding ``id`` and ``signature``), so the manifest is self-verifying and can
	7	be chained.
	8	"""
	9
	10	from __future__ import annotations
	11
	12	import fnmatch
	13	import json
	14	from dataclasses import dataclass, field
	15	from datetime import datetime, timezone
	16	from pathlib import Path
	17
	18	from . import ALGORITHM, MANIFEST_VERSION, __version__
	19	from .hashing import hash_bytes, hash_file, merkle_root
	20
	21	# Keys excluded from the canonical bytes the id is computed over. The id cannot
	22	# cover itself, and a signature is applied to the id afterwards.
	23	_ID_EXCLUDED = ("id", "signature")
	24
	25
	26	def iter_files(
	27	directory: Path, ignore: list[str] \| None, exclude: set[str]
	28	) -> list[tuple[str, Path]]:
	29	"""Return ``(posix_relpath, abspath)`` for every file under directory.
	30
	31	Paths matching an ignore glob (against the relative path) or present in
	32	exclude are skipped. Results are sorted by relative path.
	33	"""
	34	ignore = ignore or []
	35	out: list[tuple[str, Path]] = []
	36	for path in directory.rglob("*"):
	37	if not path.is_file():
	38	continue
	39	rel = path.relative_to(directory).as_posix()
	40	if rel in exclude or any(fnmatch.fnmatch(rel, pat) for pat in ignore):
	41	continue
	42	out.append((rel, path))
	43	out.sort(key=lambda pair: pair[0])
	44	return out
	45
	46
	47	def canonical_bytes(manifest: dict, exclude: tuple[str, ...] = _ID_EXCLUDED) -> bytes:
	48	"""Serialize a manifest deterministically for hashing or signing."""
	49	trimmed = {k: v for k, v in manifest.items() if k not in exclude}
	50	return json.dumps(trimmed, sort_keys=True, separators=(",", ":")).encode()
	51
	52
	53	def compute_id(manifest: dict) -> str:
	54	"""The manifest's self-id: SHA-256 of its canonical form."""
	55	return hash_bytes(canonical_bytes(manifest))
	56
	57
	58	def build_manifest(
	59	directory: str \| Path,
	60	metadata: dict \| None = None,
	61	previous: str \| None = None,
	62	ignore: list[str] \| None = None,
	63	exclude: set[str] \| None = None,
	64	) -> dict:
	65	"""Seal directory into a manifest dict (id included, unsigned)."""
	66	directory = Path(directory)
	67	if not directory.is_dir():
	68	raise FileNotFoundError(f"not a directory: {directory}")
	69
	70	files = iter_files(directory, ignore, exclude or set())
	71	entries = [
	72	{"path": rel, ALGORITHM: hash_file(abs_path), "bytes": abs_path.stat().st_size}
	73	for rel, abs_path in files
	74	]
	75	hashes = {entry["path"]: entry[ALGORITHM] for entry in entries}
	76
	77	manifest = {
	78	"manifest_version": MANIFEST_VERSION,
	79	"algorithm": ALGORITHM,
	80	"tool": f"evidence-seal/{__version__}",
	81	"created_at": datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ"),
	82	"subject": directory.name,
	83	"previous": previous,
	84	"metadata": dict(sorted((metadata or {}).items())),
	85	"ignore": sorted(ignore or []),
	86	"file_count": len(entries),
	87	"total_bytes": sum(entry["bytes"] for entry in entries),
	88	"root": merkle_root(hashes),
	89	"files": entries,
	90	}
	91	manifest["id"] = compute_id(manifest)
	92	return manifest
	93
	94
	95	def write_manifest(manifest: dict, path: str \| Path) -> None:
	96	"""Write a manifest as pretty JSON (stable key order)."""
	97	Path(path).write_text(json.dumps(manifest, indent=2, sort_keys=True) + "\n", encoding="utf-8")
	98
	99
	100	def load_manifest(path: str \| Path) -> dict:
	101	"""Load a manifest JSON file."""
	102	return json.loads(Path(path).read_text(encoding="utf-8"))
	103
	104
	105	@dataclass
	106	class VerifyResult:
	107	"""The outcome of verifying a directory against its manifest."""
	108
	109	modified: list[str] = field(default_factory=list)
	110	added: list[str] = field(default_factory=list)
	111	removed: list[str] = field(default_factory=list)
	112	id_ok: bool = True
	113	root_ok: bool = True
	114	checked: int = 0
	115
	116	@property
	117	def intact(self) -> bool:
	118	"""True only if nothing drifted and the manifest is internally sound."""
	119	return (
	120	not self.modified
	121	and not self.added
	122	and not self.removed
	123	and self.id_ok
	124	and self.root_ok
	125	)
	126
	127
	128	def verify_manifest(
	129	directory: str \| Path,
	130	manifest: dict,
	131	ignore: list[str] \| None = None,
	132	exclude: set[str] \| None = None,
	133	) -> VerifyResult:
	134	"""Compare the current contents of directory against manifest."""
	135	directory = Path(directory)
	136	recorded = {entry["path"]: entry[ALGORITHM] for entry in manifest.get("files", [])}
	137
	138	result = VerifyResult()
	139	# The manifest is only trustworthy if its id and root re-derive.
	140	result.id_ok = compute_id(manifest) == manifest.get("id")
	141	result.root_ok = merkle_root(recorded) == manifest.get("root")
	142
	143	present: dict[str, str] = {}
	144	for rel, abs_path in iter_files(directory, ignore, exclude or set()):
	145	present[rel] = hash_file(abs_path)
	146
	147	result.checked = len(present)
	148	for rel, digest in present.items():
	149	if rel not in recorded:
	150	result.added.append(rel)
	151	elif recorded[rel] != digest:
	152	result.modified.append(rel)
	153	result.removed = [rel for rel in recorded if rel not in present]
	154
	155	for bucket in (result.modified, result.added, result.removed):
	156	bucket.sort()
	157	return result
	158
	159
	160	@dataclass
	161	class ChainResult:
	162	"""The outcome of verifying a sequence of chained manifests."""
	163
	164	ok: bool
	165	length: int
	166	broken_at: int \| None = None # index whose `previous` did not match
	167	reason: str = ""
	168
	169
	170	def verify_chain(manifests: list[dict]) -> ChainResult:
	171	"""Verify manifests link oldest→newest via ``previous`` == prior ``id``.
	172
	173	Also checks that each manifest's own id re-derives, so a tampered link in
	174	the middle is caught whether the break is in the pointer or the content.
	175	"""
	176	if not manifests:
	177	return ChainResult(ok=False, length=0, reason="no manifests given")
	178
	179	for index, manifest in enumerate(manifests):
	180	if compute_id(manifest) != manifest.get("id"):
	181	return ChainResult(False, len(manifests), index, "manifest id does not re-derive")
	182	expected_prev = manifests[index - 1]["id"] if index else None
	183	if manifest.get("previous") != expected_prev:
	184	reason = (
	185	"first manifest should have no previous"
	186	if index == 0
	187	else "previous does not match the prior manifest id"
	188	)
	189	return ChainResult(False, len(manifests), index, reason)
	190
	191	return ChainResult(ok=True, length=len(manifests))

evidence_seal/signing.py added +113

		@@ -0,0 +1,113 @@
	1	"""Optional ed25519 signing of manifests.
	2
	3	Signing adds attribution — who sealed the evidence — on top of the integrity
	4	the hashes already provide. It requires the ``cryptography`` package (install
	5	``evidence-seal[sign]``); the core seal/verify path never imports this module.
	6
	7	The signature covers the manifest's canonical bytes (the same bytes its id is
	8	derived from), so a valid signature vouches for every file hash and all
	9	metadata at once.
	10	"""
	11
	12	from __future__ import annotations
	13
	14	from datetime import datetime, timezone
	15	from pathlib import Path
	16
	17	from .manifest import canonical_bytes
	18
	19
	20	def _require_crypto():
	21	try:
	22	from cryptography.hazmat.primitives.asymmetric import ed25519
	23	except ImportError as exc: # pragma: no cover - exercised via a clear message
	24	raise RuntimeError(
	25	"signing requires the 'cryptography' package — install evidence-seal[sign]"
	26	) from exc
	27	return ed25519
	28
	29
	30	def generate_keypair(private_path: str \| Path, public_path: str \| Path) -> None:
	31	"""Write a new ed25519 keypair as PEM files (private key is unencrypted)."""
	32	ed25519 = _require_crypto()
	33	from cryptography.hazmat.primitives import serialization
	34
	35	private = ed25519.Ed25519PrivateKey.generate()
	36	Path(private_path).write_bytes(
	37	private.private_bytes(
	38	encoding=serialization.Encoding.PEM,
	39	format=serialization.PrivateFormat.PKCS8,
	40	encryption_algorithm=serialization.NoEncryption(),
	41	)
	42	)
	43	Path(public_path).write_bytes(
	44	private.public_key().public_bytes(
	45	encoding=serialization.Encoding.PEM,
	46	format=serialization.PublicFormat.SubjectPublicKeyInfo,
	47	)
	48	)
	49
	50
	51	def _public_hex(public_key) -> str:
	52	from cryptography.hazmat.primitives import serialization
	53
	54	raw = public_key.public_bytes(
	55	encoding=serialization.Encoding.Raw,
	56	format=serialization.PublicFormat.Raw,
	57	)
	58	return raw.hex()
	59
	60
	61	def sign_manifest(manifest: dict, private_key_path: str \| Path) -> dict:
	62	"""Return a copy of manifest with a ``signature`` block attached."""
	63	_require_crypto()
	64	from cryptography.hazmat.primitives import serialization
	65
	66	private = serialization.load_pem_private_key(
	67	Path(private_key_path).read_bytes(), password=None
	68	)
	69	signature = private.sign(canonical_bytes(manifest))
	70	signed = dict(manifest)
	71	signed["signature"] = {
	72	"algorithm": "ed25519",
	73	"public_key": _public_hex(private.public_key()),
	74	"value": signature.hex(),
	75	"signed_at": datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ"),
	76	}
	77	return signed
	78
	79
	80	def verify_signature(manifest: dict, expected_public_key: str \| None = None) -> tuple[bool, str]:
	81	"""Verify a manifest's signature.
	82
	83	Returns ``(ok, message)``. If expected_public_key (hex) is given, the
	84	signer's key must also match it — otherwise a valid signature by any key
	85	would pass, which proves integrity but not identity.
	86	"""
	87	ed25519 = _require_crypto()
	88
	89	block = manifest.get("signature")
	90	if not block:
	91	return False, "manifest is not signed"
	92	if block.get("algorithm") != "ed25519":
	93	return False, f"unsupported signature algorithm: {block.get('algorithm')}"
	94
	95	signer_key = block.get("public_key", "")
	96	if expected_public_key and signer_key != expected_public_key:
	97	return False, "signer key does not match the expected public key"
	98
	99	try:
	100	public = ed25519.Ed25519PublicKey.from_public_bytes(bytes.fromhex(signer_key))
	101	public.verify(bytes.fromhex(block["value"]), canonical_bytes(manifest))
	102	except Exception as exc:
	103	return False, f"signature is invalid: {exc}"
	104	return True, f"valid ed25519 signature by {signer_key[:16]}…"
	105
	106
	107	def load_public_hex(public_key_path: str \| Path) -> str:
	108	"""Load a PEM public key and return its raw hex form (for --pubkey checks)."""
	109	_require_crypto()
	110	from cryptography.hazmat.primitives import serialization
	111
	112	public = serialization.load_pem_public_key(Path(public_key_path).read_bytes())
	113	return _public_hex(public)

pyproject.toml added +28

		@@ -0,0 +1,28 @@
	1	[build-system]
	2	requires = ["setuptools>=68"]
	3	build-backend = "setuptools.build_meta"
	4
	5	[project]
	6	name = "evidence-seal"
	7	version = "0.1.0"
	8	description = "Tamper-evident seals and chain of custody for audit evidence packages."
	9	readme = "README.md"
	10	requires-python = ">=3.10"
	11	license = { text = "GPL-3.0-or-later" }
	12	authors = [{ name = "Audit Labs" }]
	13	# The core seal/verify/chain path is pure standard library.
	14	dependencies = []
	15
	16	[project.optional-dependencies]
	17	sign = ["cryptography>=42.0"]
	18	dev = ["pytest>=8.0", "ruff>=0.5", "cryptography>=42.0"]
	19
	20	[project.scripts]
	21	evidence-seal = "evidence_seal.cli:main"
	22
	23	[project.urls]
	24	Homepage = "https://audit-labs.dev"
	25	Repository = "https://github.com/audit-labs/evidence-seal"
	26
	27	[tool.setuptools]
	28	packages = ["evidence_seal"]

requirements-dev.txt added +3

		@@ -0,0 +1,3 @@
	1	pytest>=8.0
	2	ruff>=0.5
	3	cryptography>=42.0

ruff.toml added +7

		@@ -0,0 +1,7 @@
	1	# Ruff configuration for evidence-seal.
	2	#
	3	# BLE001 is disabled because signature verification deliberately catches any
	4	# exception and reports it as a failed verification rather than crashing — an
	5	# invalid signature is a normal, expected outcome, not a program error.
	6	[lint]
	7	ignore = ["BLE001"]

tests/test_cli.py added +74

		@@ -0,0 +1,74 @@
	1	"""End-to-end tests for the CLI, covering exit codes."""
	2
	3	import pytest
	4
	5	from evidence_seal.cli import OK, USAGE, main
	6
	7
	8	@pytest.fixture
	9	def pkg(tmp_path):
	10	d = tmp_path / "aws_audit_acme_2026-01-01"
	11	d.mkdir()
	12	(d / "iam.csv").write_text("user,mfa\nalice,true\n", encoding="utf-8")
	13	return d
	14
	15
	16	def test_seal_then_verify_intact(pkg, tmp_path):
	17	manifest = tmp_path / "m.json"
	18	assert main(["seal", str(pkg), "--out", str(manifest), "--meta", "engagement=ACME"]) == OK
	19	assert manifest.exists()
	20	assert main(["verify", str(pkg), "--manifest", str(manifest)]) == OK
	21
	22
	23	def test_verify_fails_after_tamper(pkg, tmp_path):
	24	manifest = tmp_path / "m.json"
	25	main(["seal", str(pkg), "--out", str(manifest)])
	26	(pkg / "iam.csv").write_text("user,mfa\nalice,false\n", encoding="utf-8")
	27	assert main(["verify", str(pkg), "--manifest", str(manifest)]) == 1
	28
	29
	30	def test_default_manifest_path(pkg):
	31	# No --out: manifest lands next to the dir and verify finds it by default.
	32	assert main(["seal", str(pkg)]) == OK
	33	assert (pkg.parent / f"{pkg.name}.manifest.json").exists()
	34	assert main(["verify", str(pkg)]) == OK
	35
	36
	37	def test_manifest_inside_dir_is_not_self_sealed(pkg):
	38	inside = pkg / "seal.json"
	39	assert main(["seal", str(pkg), "--out", str(inside)]) == OK
	40	# Verifying still passes even though the manifest now sits inside the dir.
	41	assert main(["verify", str(pkg), "--manifest", str(inside)]) == OK
	42
	43
	44	def test_chain_command(pkg, tmp_path):
	45	m1, m2 = tmp_path / "m1.json", tmp_path / "m2.json"
	46	main(["seal", str(pkg), "--out", str(m1)])
	47	(pkg / "iam.csv").write_text("user,mfa\nalice,true\nbob,true\n", encoding="utf-8")
	48	main(["seal", str(pkg), "--out", str(m2), "--prev", str(m1)])
	49	assert main(["chain", str(m1), str(m2)]) == OK
	50	assert main(["chain", str(m2), str(m1)]) == 1
	51
	52
	53	def test_bad_metadata_is_usage_error(pkg, tmp_path):
	54	assert main(["seal", str(pkg), "--out", str(tmp_path / "m.json"), "--meta", "novalue"]) == USAGE
	55
	56
	57	def test_sign_and_verify_via_cli(pkg, tmp_path):
	58	pytest.importorskip("cryptography")
	59	priv, pub = tmp_path / "k.key", tmp_path / "k.pub"
	60	assert main(["keygen", "--private", str(priv), "--public", str(pub)]) == OK
	61	manifest = tmp_path / "m.json"
	62	assert main(["seal", str(pkg), "--out", str(manifest), "--sign", str(priv)]) == OK
	63	assert main(["verify", str(pkg), "--manifest", str(manifest), "--pubkey", str(pub)]) == OK
	64
	65
	66	def test_verify_rejects_wrong_signer(pkg, tmp_path):
	67	pytest.importorskip("cryptography")
	68	priv, pub = tmp_path / "k.key", tmp_path / "k.pub"
	69	other_pub = tmp_path / "o.pub"
	70	main(["keygen", "--private", str(priv), "--public", str(pub)])
	71	main(["keygen", "--private", str(tmp_path / "o.key"), "--public", str(other_pub)])
	72	manifest = tmp_path / "m.json"
	73	main(["seal", str(pkg), "--out", str(manifest), "--sign", str(priv)])
	74	assert main(["verify", str(pkg), "--manifest", str(manifest), "--pubkey", str(other_pub)]) == 1

tests/test_hashing.py added +39

		@@ -0,0 +1,39 @@
	1	"""Tests for file hashing and the Merkle root."""
	2
	3	from evidence_seal.hashing import hash_bytes, hash_file, merkle_root
	4
	5
	6	def test_hash_file_matches_known_sha256(tmp_path):
	7	f = tmp_path / "x.txt"
	8	f.write_bytes(b"hello")
	9	# Known SHA-256 of "hello".
	10	assert hash_file(f) == "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"
	11	assert hash_bytes(b"hello") == hash_file(f)
	12
	13
	14	def test_merkle_root_is_order_independent():
	15	a = {"a": "1", "b": "2", "c": "3"}
	16	b = {"c": "3", "a": "1", "b": "2"}
	17	assert merkle_root(a) == merkle_root(b)
	18
	19
	20	def test_merkle_root_changes_on_content():
	21	base = {"a": "1", "b": "2"}
	22	changed = {"a": "1", "b": "changed"}
	23	assert merkle_root(base) != merkle_root(changed)
	24
	25
	26	def test_merkle_root_changes_on_rename():
	27	# Same content hash, different path -> different root (path is bound in).
	28	assert merkle_root({"a": "1"}) != merkle_root({"b": "1"})
	29
	30
	31	def test_empty_root_is_defined_and_distinct():
	32	assert merkle_root({}) == hash_bytes(b"empty")
	33	assert merkle_root({}) != merkle_root({"a": "1"})
	34
	35
	36	def test_odd_number_of_leaves():
	37	# Three leaves exercises the duplicate-last branch; just needs to be stable.
	38	entries = {"a": "1", "b": "2", "c": "3"}
	39	assert merkle_root(entries) == merkle_root(dict(entries))

tests/test_manifest.py added +102

		@@ -0,0 +1,102 @@
	1	"""Tests for building, verifying, and chaining manifests."""
	2
	3	import pytest
	4
	5	from evidence_seal.manifest import (
	6	build_manifest,
	7	compute_id,
	8	verify_chain,
	9	verify_manifest,
	10	)
	11
	12
	13	@pytest.fixture
	14	def pkg(tmp_path):
	15	d = tmp_path / "aws_audit_acme_2026-01-01"
	16	d.mkdir()
	17	(d / "iam.csv").write_text("user,mfa\nalice,true\n", encoding="utf-8")
	18	(d / "summary.txt").write_text("ok\n", encoding="utf-8")
	19	return d
	20
	21
	22	def test_build_manifest_shape(pkg):
	23	m = build_manifest(pkg, metadata={"engagement": "ACME"})
	24	assert m["subject"] == "aws_audit_acme_2026-01-01"
	25	assert m["file_count"] == 2
	26	assert m["metadata"] == {"engagement": "ACME"}
	27	assert [f["path"] for f in m["files"]] == ["iam.csv", "summary.txt"]
	28	assert m["id"] == compute_id(m)
	29
	30
	31	def test_verify_clean(pkg):
	32	m = build_manifest(pkg)
	33	result = verify_manifest(pkg, m)
	34	assert result.intact
	35	assert result.checked == 2
	36
	37
	38	def test_verify_detects_modification(pkg):
	39	m = build_manifest(pkg)
	40	(pkg / "iam.csv").write_text("user,mfa\nalice,false\n", encoding="utf-8")
	41	result = verify_manifest(pkg, m)
	42	assert not result.intact
	43	assert result.modified == ["iam.csv"]
	44
	45
	46	def test_verify_detects_added_and_removed(pkg):
	47	m = build_manifest(pkg)
	48	(pkg / "extra.csv").write_text("new\n", encoding="utf-8")
	49	(pkg / "summary.txt").unlink()
	50	result = verify_manifest(pkg, m)
	51	assert result.added == ["extra.csv"]
	52	assert result.removed == ["summary.txt"]
	53	assert not result.intact
	54
	55
	56	def test_verify_detects_manifest_tampering(pkg):
	57	m = build_manifest(pkg)
	58	# Rewrite a recorded hash but leave the (now stale) id in place.
	59	m["files"][0]["sha256"] = "0" * 64
	60	result = verify_manifest(pkg, m)
	61	assert not result.id_ok
	62	assert not result.root_ok
	63	assert not result.intact
	64
	65
	66	def test_ignore_patterns_excluded_and_recorded(pkg):
	67	(pkg / "notes.tmp").write_text("scratch\n", encoding="utf-8")
	68	m = build_manifest(pkg, ignore=["*.tmp"])
	69	assert m["ignore"] == ["*.tmp"]
	70	assert all(not f["path"].endswith(".tmp") for f in m["files"])
	71	# Verify with the same ignore keeps it intact despite the tmp file present.
	72	assert verify_manifest(pkg, m, ignore=m["ignore"]).intact
	73
	74
	75	def test_chain_links(pkg):
	76	m1 = build_manifest(pkg)
	77	(pkg / "iam.csv").write_text("user,mfa\nalice,true\nbob,true\n", encoding="utf-8")
	78	m2 = build_manifest(pkg, previous=m1["id"])
	79	assert verify_chain([m1, m2]).ok
	80
	81
	82	def test_chain_detects_wrong_order(pkg):
	83	m1 = build_manifest(pkg)
	84	m2 = build_manifest(pkg, previous=m1["id"])
	85	result = verify_chain([m2, m1])
	86	assert not result.ok
	87	assert result.broken_at == 0
	88
	89
	90	def test_chain_detects_spliced_entry(pkg):
	91	m1 = build_manifest(pkg)
	92	m2 = build_manifest(pkg, previous=m1["id"])
	93	m3 = build_manifest(pkg, previous=m2["id"])
	94	# Drop the middle manifest: m3.previous no longer matches m1.id.
	95	result = verify_chain([m1, m3])
	96	assert not result.ok
	97	assert result.broken_at == 1
	98
	99
	100	def test_missing_directory_raises(tmp_path):
	101	with pytest.raises(FileNotFoundError):
	102	build_manifest(tmp_path / "nope")

tests/test_signing.py added +63

		@@ -0,0 +1,63 @@
	1	"""Tests for optional ed25519 signing (skipped if cryptography is absent)."""
	2
	3	import pytest
	4
	5	pytest.importorskip("cryptography")
	6
	7	from evidence_seal.manifest import build_manifest
	8	from evidence_seal.signing import (
	9	generate_keypair,
	10	load_public_hex,
	11	sign_manifest,
	12	verify_signature,
	13	)
	14
	15
	16	@pytest.fixture
	17	def sealed(tmp_path):
	18	d = tmp_path / "pkg"
	19	d.mkdir()
	20	(d / "a.csv").write_text("x\n", encoding="utf-8")
	21	return build_manifest(d)
	22
	23
	24	@pytest.fixture
	25	def keys(tmp_path):
	26	priv, pub = tmp_path / "k.key", tmp_path / "k.pub"
	27	generate_keypair(priv, pub)
	28	return priv, pub
	29
	30
	31	def test_sign_then_verify(sealed, keys):
	32	priv, pub = keys
	33	signed = sign_manifest(sealed, priv)
	34	ok, _ = verify_signature(signed)
	35	assert ok
	36	# And the embedded key matches the PEM public key.
	37	ok_matched, _ = verify_signature(signed, load_public_hex(pub))
	38	assert ok_matched
	39
	40
	41	def test_unsigned_manifest_reports_clearly(sealed):
	42	ok, message = verify_signature(sealed)
	43	assert not ok
	44	assert "not signed" in message
	45
	46
	47	def test_tampered_manifest_fails_signature(sealed, keys):
	48	priv, _ = keys
	49	signed = sign_manifest(sealed, priv)
	50	# Alter a hash after signing; the signature no longer covers it.
	51	signed["files"][0]["sha256"] = "0" * 64
	52	ok, _ = verify_signature(signed)
	53	assert not ok
	54
	55
	56	def test_wrong_expected_key_rejected(sealed, tmp_path, keys):
	57	priv, _ = keys
	58	signed = sign_manifest(sealed, priv)
	59	other_priv, other_pub = tmp_path / "o.key", tmp_path / "o.pub"
	60	generate_keypair(other_priv, other_pub)
	61	ok, message = verify_signature(signed, load_public_hex(other_pub))
	62	assert not ok
	63	assert "does not match" in message

Commit 5a9365de64

Commit `5a9365de64`