solpbc.org
personal memory agent
fix(transparency): strip the minisign trusted-comment prefix
Real minisign signatures store line 3 as "trusted comment: <comment>", so both signer implementations now strip exactly that prefix and fail closed when it is absent.
The fake signer now emits the real four-line format. Previously it wrote an unprefixed line 3, which masked the real-format failure in parse_trusted_comment and the publisher verification path.
author
Jer Miller
date
(Jul 22, 2026, 5:00 PM -0600)
commit
09a637aa
09a637aaf2ace0e15a79fa44be5b8ade80f03d6f
parent
d4c84d2d
d4c84d2d5fedbfe3399b5d3c6400fc1b6ae4a320
+55
-7
+29
-5
scripts/transparency_signing.py
+29
-5
scripts/transparency_signing.py
···
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REQUIRED_MINISIGN_VERSION = "minisign 0.12"
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MISSING_MINISIGN_MESSAGE = "transparency-minisign: minisign 0.12 is required; install it with: sudo dnf install minisign"
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TRUSTED_COMMENT_PREFIX = "trusted comment: "
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class TransparencySigner(Protocol):
···
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]
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)
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return version
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def _extract_trusted_comment(line: str, *, malformed_error: str, repair: str) -> str:
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if not line.startswith(TRUSTED_COMMENT_PREFIX):
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raise DriverError(
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[
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failure(
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malformed_error,
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expected=f"{TRUSTED_COMMENT_PREFIX}<trusted comment>",
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actual=line,
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repair=repair,
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)
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]
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)
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return line[len(TRUSTED_COMMENT_PREFIX) :]
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@dataclass
···
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text=True,
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check=False,
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)
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comment = result.stdout.strip()
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if result.returncode != 0:
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raise DriverError(
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[
···
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)
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]
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)
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comment = result.stdout.strip()
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if comment != expected_trusted_comment:
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raise DriverError(
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[
···
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)
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]
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)
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return lines[2]
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return _extract_trusted_comment(
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lines[2],
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malformed_error="transparency minisign trusted comment line is malformed",
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repair="re-sign the transparency object with minisign 0.12",
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)
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@dataclass(frozen=True)
···
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(
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"untrusted comment: fake transparency signature",
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base64.b64encode(digest).decode("ascii"),
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trusted_comment,
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f"trusted comment: {trusted_comment}",
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f"trusted comment signature: {hashlib.sha256(digest).hexdigest()}",
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"",
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)
···
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)
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]
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)
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comment = lines[2]
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comment = self.trusted_comment(signature_path)
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if comment != expected_trusted_comment:
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raise DriverError(
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[
···
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)
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]
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)
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return lines[2]
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return _extract_trusted_comment(
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lines[2],
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malformed_error="fake transparency trusted comment line is malformed",
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repair="re-sign the transparency object",
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)
+26
-2
tests/test_transparency_signing.py
+26
-2
tests/test_transparency_signing.py
···
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import pytest
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from scripts.release_candidate_driver import DriverError
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from scripts.transparency_signing import FakeTransparencySigner
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from scripts.transparency_signing import TRUSTED_COMMENT_PREFIX, FakeTransparencySigner
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def test_fake_signer_verifies_body_and_trusted_comment(tmp_path: Path) -> None:
···
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message.write_bytes(b'{"ok":1}\n')
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signer.sign_file(message, signature, trusted_comment=comment)
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lines = signature.read_text(encoding="utf-8").splitlines()
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assert lines[2] == comment
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assert len(lines) == 4
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assert lines[2] == f"{TRUSTED_COMMENT_PREFIX}{comment}"
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assert signer.trusted_comment(signature) == comment
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···
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with pytest.raises(DriverError) as error:
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signer.verify_file(message, signature, expected_trusted_comment="two")
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assert error.value.failures[0].error == "fake transparency trusted comment mismatch"
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def test_fake_signer_rejects_missing_trusted_comment_prefix(tmp_path: Path) -> None:
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signer = FakeTransparencySigner()
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signature = tmp_path / "latest.json.minisig"
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signature.write_text(
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"\n".join(
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(
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"untrusted comment: fake transparency signature",
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"ZmFrZQ==",
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"raw trusted comment",
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"trusted comment signature: fake",
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"",
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)
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),
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encoding="utf-8",
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)
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with pytest.raises(DriverError) as error:
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signer.trusted_comment(signature)
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assert (
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error.value.failures[0].error
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== "fake transparency trusted comment line is malformed"
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)