#!/usr/bin/env python3 """Positive and negative controls for the released evidence-binding verifier.""" from __future__ import annotations import json import shutil import subprocess import tempfile from pathlib import Path ROOT = Path(__file__).resolve().parents[1] VERIFY = ROOT / "scripts" / "verify_evidence_bindings.py" def fixture_copy(parent: Path) -> Path: fixture = parent / "fixture" shutil.copytree(ROOT, fixture, ignore=shutil.ignore_patterns(".git", "artifacts")) return fixture def receipt_path(fixture: Path, value: str) -> None: index_path = fixture / "evidence" / "evidence-index-v0.2.0.json" index = json.loads(index_path.read_text()) next(receipt for receipt in index["receipts"] if receipt["case_id"] == "RS-01")["path"] = value index_path.write_text(json.dumps(index, indent=2) + "\n") def rejected(label: str, mutate) -> None: with tempfile.TemporaryDirectory() as temporary: fixture = fixture_copy(Path(temporary)) mutate(fixture) result = subprocess.run(["python3", str(VERIFY), str(fixture)], capture_output=True, text=True) assert result.returncode != 0, f"{label} unexpectedly passed" assert "invalid evidence binding:" in result.stderr, result.stderr with tempfile.TemporaryDirectory() as temporary: fixture = fixture_copy(Path(temporary)) subprocess.run(["python3", str(VERIFY), str(fixture)], check=True) rejected( "payload-byte corruption", lambda fixture: (fixture / "evidence" / "payloads" / "RS-01.json").write_text( (fixture / "evidence" / "payloads" / "RS-01.json").read_text() + "\n" ), ) rejected("malformed payload", lambda fixture: (fixture / "evidence" / "payloads" / "RS-01.json").write_text("{\n")) for label, value in ( ("path traversal", "../README.md"), ("absolute path", "/tmp/outside.json"), ("missing local payload", "evidence/payloads/does-not-exist.json"), ("external URL-like path", "https://example.invalid/evidence.json"), ): rejected(label, lambda fixture, value=value: receipt_path(fixture, value)) print("valid: clean fixture accepted; corruption and locality controls rejected")