test_security_agent_impersonation.py
python
sha256:88ac91129873e6a496e9189515aa690eb893ae25d69c8f72af141a2be5068eb3
docs: docstring sprint contract→find-symbol — idiomatic run…
Sonnet 4.6
patch
139 days ago
| 1 | """Agent impersonation security tests — Ed25519 provenance signing. |
| 2 | |
| 3 | Attack surface |
| 4 | -------------- |
| 5 | Commit records in Muse carry identity fields that are NEVER validated against |
| 6 | the authenticated user: ``author``, ``agent_id``, ``model_id``, etc. |
| 7 | Any caller with access to the CLI can write commits claiming to be authored by |
| 8 | anyone — human, agent, or a previously-trusted identity. |
| 9 | |
| 10 | Signing model (format_version 7) |
| 11 | --------------------------------- |
| 12 | Commits signed with ``--sign`` use Ed25519 (same keypair as MSign request |
| 13 | authentication). The ``signer_public_key`` field embeds the signer's raw |
| 14 | public key bytes (base64url, 43 chars) so verification is fully offline. |
| 15 | |
| 16 | The signed input is ``provenance_payload(commit_id, author, agent_id, ...)`` |
| 17 | — a SHA-256 digest that binds content identity to authorship claims. Any |
| 18 | mutation of author, agent_id, model_id, toolchain_id, or prompt_hash after |
| 19 | signing is detected by ``run_verify``. |
| 20 | |
| 21 | Legacy versions |
| 22 | --------------- |
| 23 | format_version <= 6 used HMAC-SHA256. These commits are no longer |
| 24 | verifiable and are treated as unsigned by ``run_verify``. |
| 25 | """ |
| 26 | |
| 27 | from __future__ import annotations |
| 28 | |
| 29 | import base64 |
| 30 | import datetime |
| 31 | import json |
| 32 | import pathlib |
| 33 | |
| 34 | import pytest |
| 35 | from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey |
| 36 | from cryptography.hazmat.primitives.serialization import Encoding, PublicFormat |
| 37 | |
| 38 | from muse.core.store import _commit_path, _snapshot_path |
| 39 | from muse.core.provenance import ( |
| 40 | encode_public_key, |
| 41 | provenance_payload, |
| 42 | public_key_fingerprint, |
| 43 | sign_commit_ed25519, |
| 44 | sign_commit_record, |
| 45 | verify_commit_ed25519, |
| 46 | ) |
| 47 | from muse.core.snapshot import compute_commit_id |
| 48 | from muse.core.validation import sanitize_provenance |
| 49 | from muse.core.verify import VerifyResult, run_verify |
| 50 | from muse.core._types import Manifest, MsgpackDict, blob_id, decode_pubkey, encode_sig |
| 51 | |
| 52 | |
| 53 | # --------------------------------------------------------------------------- |
| 54 | # Helpers |
| 55 | # --------------------------------------------------------------------------- |
| 56 | |
| 57 | def _gen_key() -> Ed25519PrivateKey: |
| 58 | return Ed25519PrivateKey.generate() |
| 59 | |
| 60 | |
| 61 | def _pub_bytes(key: Ed25519PrivateKey) -> bytes: |
| 62 | return key.public_key().public_bytes(Encoding.Raw, PublicFormat.Raw) |
| 63 | |
| 64 | |
| 65 | def _pub_b64(key: Ed25519PrivateKey) -> str: |
| 66 | _, b64 = encode_public_key(key) |
| 67 | return b64 |
| 68 | |
| 69 | |
| 70 | def _make_repo(tmp_path: pathlib.Path) -> pathlib.Path: |
| 71 | """Create a minimal .muse/ repository skeleton.""" |
| 72 | muse = tmp_path / ".muse" |
| 73 | for d in ("objects", "commits", "snapshots", "refs/heads"): |
| 74 | (muse / d).mkdir(parents=True, exist_ok=True) |
| 75 | (muse / "repo.json").write_text('{"repo_id": "test-repo"}', encoding="utf-8") |
| 76 | (muse / "HEAD").write_text("ref: refs/heads/main\n", encoding="utf-8") |
| 77 | return tmp_path |
| 78 | |
| 79 | |
| 80 | _COMMITTED_AT = datetime.datetime(2026, 1, 1, tzinfo=datetime.timezone.utc) |
| 81 | |
| 82 | |
| 83 | def _make_real_commit_id( |
| 84 | snapshot_id: str = "a" * 64, |
| 85 | parent: str | None = None, |
| 86 | message: str = "test", |
| 87 | ) -> str: |
| 88 | """Return the canonical commit_id matching the fixed 2026-01-01 timestamp.""" |
| 89 | parents = [parent] if parent else [] |
| 90 | return compute_commit_id(parents, snapshot_id, message, _COMMITTED_AT.isoformat()) |
| 91 | |
| 92 | |
| 93 | def _v7_sig( |
| 94 | commit_id: str, |
| 95 | key: Ed25519PrivateKey, |
| 96 | *, |
| 97 | author: str = "", |
| 98 | agent_id: str = "", |
| 99 | model_id: str = "", |
| 100 | toolchain_id: str = "", |
| 101 | prompt_hash: str = "", |
| 102 | committed_at: str = _COMMITTED_AT.isoformat(), |
| 103 | ) -> str: |
| 104 | """Compute a format_version 7 Ed25519 signature (over provenance_payload).""" |
| 105 | payload = provenance_payload( |
| 106 | commit_id, |
| 107 | author=author, |
| 108 | agent_id=agent_id, |
| 109 | model_id=model_id, |
| 110 | toolchain_id=toolchain_id, |
| 111 | prompt_hash=prompt_hash, |
| 112 | committed_at=committed_at, |
| 113 | ) |
| 114 | return sign_commit_ed25519(payload, key) |
| 115 | |
| 116 | |
| 117 | def _write_commit( |
| 118 | root: pathlib.Path, |
| 119 | commit_id: str, |
| 120 | *, |
| 121 | snapshot_id: str = "a" * 64, |
| 122 | parent: str | None = None, |
| 123 | message: str = "test", |
| 124 | author: str = "", |
| 125 | agent_id: str = "", |
| 126 | model_id: str = "", |
| 127 | toolchain_id: str = "", |
| 128 | prompt_hash: str = "", |
| 129 | signature: str = "", |
| 130 | signer_public_key: str = "", |
| 131 | signer_key_id: str = "", |
| 132 | format_version: int = 7, |
| 133 | ) -> None: |
| 134 | """Write a content-hash-valid commit record to .muse/commits/<commit_id>.msgpack. |
| 135 | |
| 136 | The ``commit_id`` MUST equal ``_make_real_commit_id(snapshot_id, parent, message)`` |
| 137 | for the record to pass the store's content-hash verification. |
| 138 | """ |
| 139 | import msgpack |
| 140 | |
| 141 | record: MsgpackDict = { |
| 142 | "commit_id": commit_id, |
| 143 | "repo_id": "test-repo", |
| 144 | "branch": "main", |
| 145 | "snapshot_id": snapshot_id, |
| 146 | "message": message, |
| 147 | "committed_at": _COMMITTED_AT.isoformat(), |
| 148 | "parent_commit_id": parent, |
| 149 | "parent2_commit_id": None, |
| 150 | "author": author, |
| 151 | "metadata": {}, |
| 152 | "structured_delta": None, |
| 153 | "sem_ver_bump": "none", |
| 154 | "breaking_changes": [], |
| 155 | "agent_id": agent_id, |
| 156 | "model_id": model_id, |
| 157 | "toolchain_id": toolchain_id, |
| 158 | "prompt_hash": prompt_hash, |
| 159 | "signature": signature, |
| 160 | "signer_public_key": signer_public_key, |
| 161 | "signer_key_id": signer_key_id, |
| 162 | "format_version": format_version, |
| 163 | "reviewed_by": [], |
| 164 | "test_runs": 0, |
| 165 | } |
| 166 | path = _commit_path(root, commit_id) |
| 167 | path.parent.mkdir(parents=True, exist_ok=True) |
| 168 | path.write_bytes(msgpack.packb(record)) |
| 169 | |
| 170 | |
| 171 | _EMPTY_SNAP_ID = blob_id(b"") |
| 172 | |
| 173 | |
| 174 | def _write_snapshot(root: pathlib.Path, snapshot_id: str) -> None: |
| 175 | """Write a minimal snapshot record.""" |
| 176 | import msgpack |
| 177 | |
| 178 | snap_path = _snapshot_path(root, snapshot_id) |
| 179 | snap_path.parent.mkdir(parents=True, exist_ok=True) |
| 180 | snap_path.write_bytes( |
| 181 | msgpack.packb({ |
| 182 | "snapshot_id": snapshot_id, |
| 183 | "manifest": {}, |
| 184 | "created_at": "2026-01-01T00:00:00+00:00", |
| 185 | }) |
| 186 | ) |
| 187 | |
| 188 | |
| 189 | def _set_branch_ref(root: pathlib.Path, branch: str, commit_id: str) -> None: |
| 190 | ref_path = root / ".muse" / "refs" / "heads" / branch |
| 191 | ref_path.parent.mkdir(parents=True, exist_ok=True) |
| 192 | ref_path.write_text(commit_id, encoding="utf-8") |
| 193 | |
| 194 | |
| 195 | def _fake_commit_id(seed: str = "a") -> str: |
| 196 | import hashlib |
| 197 | return hashlib.sha256(seed.encode()).hexdigest() |
| 198 | |
| 199 | |
| 200 | # =========================================================================== |
| 201 | # Author field sanitization |
| 202 | # =========================================================================== |
| 203 | |
| 204 | |
| 205 | class TestAuthorSanitization: |
| 206 | """sanitize_provenance must strip control chars from the author field.""" |
| 207 | |
| 208 | def test_clean_author_unchanged(self) -> None: |
| 209 | assert sanitize_provenance("gabriel") == "gabriel" |
| 210 | |
| 211 | def test_esc_in_author_stripped(self) -> None: |
| 212 | raw = "\x1b[31mfake-human\x1b[0m" |
| 213 | clean = sanitize_provenance(raw) |
| 214 | assert "\x1b" not in clean |
| 215 | assert "fake-human" in clean |
| 216 | |
| 217 | def test_newline_in_author_stripped(self) -> None: |
| 218 | raw = "gabriel\[email protected]" |
| 219 | clean = sanitize_provenance(raw) |
| 220 | assert "\n" not in clean |
| 221 | |
| 222 | def test_cr_in_author_stripped(self) -> None: |
| 223 | raw = "gabriel\r\nlinus" |
| 224 | clean = sanitize_provenance(raw) |
| 225 | assert "\r" not in clean |
| 226 | |
| 227 | def test_bel_in_author_stripped(self) -> None: |
| 228 | raw = "gabriel\x07linus" |
| 229 | clean = sanitize_provenance(raw) |
| 230 | assert "\x07" not in clean |
| 231 | |
| 232 | @pytest.mark.parametrize("char_val", range(0x00, 0x20)) |
| 233 | def test_c0_control_chars_stripped(self, char_val: int) -> None: |
| 234 | char = chr(char_val) |
| 235 | raw = f"prefix{char}suffix" |
| 236 | result = sanitize_provenance(raw) |
| 237 | assert char not in result |
| 238 | |
| 239 | def test_del_stripped(self) -> None: |
| 240 | assert "\x7f" not in sanitize_provenance("a\x7fb") |
| 241 | |
| 242 | def test_author_cap_at_256_chars(self) -> None: |
| 243 | long_author = "a" * 300 |
| 244 | stored = sanitize_provenance(long_author[:256]) |
| 245 | assert len(stored) == 256 |
| 246 | |
| 247 | def test_unicode_author_preserved(self) -> None: |
| 248 | raw = "gabriel (加布里埃尔)" |
| 249 | assert sanitize_provenance(raw) == raw |
| 250 | |
| 251 | def test_email_style_author_preserved(self) -> None: |
| 252 | raw = "Gabriel <[email protected]>" |
| 253 | assert sanitize_provenance(raw) == raw |
| 254 | |
| 255 | |
| 256 | # =========================================================================== |
| 257 | # commit_id does NOT include author — post-signing mutation |
| 258 | # =========================================================================== |
| 259 | |
| 260 | |
| 261 | class TestAuthorNotInCommitId: |
| 262 | """author is absent from commit_id — this is by design, not a bug. |
| 263 | |
| 264 | Commit identity is content-addressed over (snapshot, message, parents, |
| 265 | timestamp). Author is display metadata. The Ed25519 signing scheme |
| 266 | (format_version 7) covers author via provenance_payload, making post-sign |
| 267 | mutation detectable. |
| 268 | """ |
| 269 | |
| 270 | def test_same_commit_id_different_authors(self) -> None: |
| 271 | """Two commits differing only in author share the same commit_id.""" |
| 272 | iso = datetime.datetime(2026, 1, 1, tzinfo=datetime.timezone.utc).isoformat() |
| 273 | id_gabriel = compute_commit_id([], "snap" * 16, "msg", iso) |
| 274 | id_linus = compute_commit_id([], "snap" * 16, "msg", iso) |
| 275 | assert id_gabriel == id_linus |
| 276 | |
| 277 | def test_v7_author_mutation_detected_via_payload(self) -> None: |
| 278 | """Ed25519 (v7): mutating author changes the provenance payload → sig fails.""" |
| 279 | key = _gen_key() |
| 280 | commit_id = _fake_commit_id("v7-author-mutation") |
| 281 | |
| 282 | original_payload = provenance_payload(commit_id, author="gabriel", agent_id="cursor-bot") |
| 283 | sig = sign_commit_ed25519(original_payload, key) |
| 284 | pub = _pub_bytes(key) |
| 285 | |
| 286 | # Original payload verifies. |
| 287 | assert verify_commit_ed25519(original_payload, sig, pub) |
| 288 | |
| 289 | # Mutated author → different payload → fails. |
| 290 | mutated_payload = provenance_payload(commit_id, author="[email protected]", agent_id="cursor-bot") |
| 291 | assert not verify_commit_ed25519(mutated_payload, sig, pub) |
| 292 | |
| 293 | def test_forged_signature_fails_verification(self) -> None: |
| 294 | """A fabricated signature that was never produced by the key fails.""" |
| 295 | key = _gen_key() |
| 296 | payload = provenance_payload(_fake_commit_id("real-commit")) |
| 297 | forged_sig = encode_sig("ed25519", b"\x00" * 64) # correct format, wrong bytes |
| 298 | |
| 299 | assert not verify_commit_ed25519(payload, forged_sig, _pub_bytes(key)) |
| 300 | |
| 301 | def test_wrong_key_fails_verification(self) -> None: |
| 302 | """A signature produced by one key does not validate against another.""" |
| 303 | key1 = _gen_key() |
| 304 | key2 = _gen_key() |
| 305 | payload = provenance_payload(_fake_commit_id("commit")) |
| 306 | sig = sign_commit_ed25519(payload, key1) |
| 307 | |
| 308 | assert not verify_commit_ed25519(payload, sig, _pub_bytes(key2)) |
| 309 | |
| 310 | def test_empty_signature_is_falsy(self) -> None: |
| 311 | """Empty signature is the 'unsigned' sentinel.""" |
| 312 | key = _gen_key() |
| 313 | assert not verify_commit_ed25519(provenance_payload("commit_id"), "", _pub_bytes(key)) |
| 314 | |
| 315 | |
| 316 | # =========================================================================== |
| 317 | # muse verify — Ed25519 signature verification |
| 318 | # =========================================================================== |
| 319 | |
| 320 | |
| 321 | class TestVerifySignatures: |
| 322 | """run_verify must check Ed25519 signatures on format_version=7 commits.""" |
| 323 | |
| 324 | def test_valid_signature_passes(self, tmp_path: pathlib.Path) -> None: |
| 325 | root = _make_repo(tmp_path) |
| 326 | snap_id = _EMPTY_SNAP_ID |
| 327 | _write_snapshot(root, snap_id) |
| 328 | |
| 329 | key = _gen_key() |
| 330 | commit_id = _make_real_commit_id(snapshot_id=snap_id, message="sign-pass") |
| 331 | sig = _v7_sig(commit_id, key, agent_id="bot-v1") |
| 332 | |
| 333 | _write_commit( |
| 334 | root, commit_id, |
| 335 | snapshot_id=snap_id, |
| 336 | message="sign-pass", |
| 337 | agent_id="bot-v1", |
| 338 | signature=sig, |
| 339 | signer_public_key=_pub_b64(key), |
| 340 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), |
| 341 | format_version=7, |
| 342 | ) |
| 343 | _set_branch_ref(root, "main", commit_id) |
| 344 | |
| 345 | result = run_verify(root, check_objects=False) |
| 346 | assert result["signatures_checked"] == 1 |
| 347 | assert result["all_ok"] |
| 348 | assert result["failures"] == [] |
| 349 | |
| 350 | def test_forged_signature_detected(self, tmp_path: pathlib.Path) -> None: |
| 351 | root = _make_repo(tmp_path) |
| 352 | snap_id = _EMPTY_SNAP_ID |
| 353 | _write_snapshot(root, snap_id) |
| 354 | |
| 355 | key = _gen_key() |
| 356 | commit_id = _make_real_commit_id(snapshot_id=snap_id, message="forged") |
| 357 | forged_sig = encode_sig("ed25519", b"\x00" * 64) # correct format, wrong bytes — never produced by the key |
| 358 | |
| 359 | _write_commit( |
| 360 | root, commit_id, |
| 361 | snapshot_id=snap_id, |
| 362 | message="forged", |
| 363 | agent_id="bot-v1", |
| 364 | signature=forged_sig, |
| 365 | signer_public_key=_pub_b64(key), |
| 366 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), |
| 367 | format_version=7, |
| 368 | ) |
| 369 | _set_branch_ref(root, "main", commit_id) |
| 370 | |
| 371 | result = run_verify(root, check_objects=False) |
| 372 | assert result["signatures_checked"] == 1 |
| 373 | assert not result["all_ok"] |
| 374 | sig_failures = [f for f in result["failures"] if f["kind"] == "signature"] |
| 375 | assert len(sig_failures) == 1 |
| 376 | assert "INVALID" in sig_failures[0]["error"] |
| 377 | |
| 378 | def test_missing_public_key_reported_as_failure(self, tmp_path: pathlib.Path) -> None: |
| 379 | """A v7 commit with signature but no signer_public_key is a key_missing failure.""" |
| 380 | root = _make_repo(tmp_path) |
| 381 | snap_id = _EMPTY_SNAP_ID |
| 382 | _write_snapshot(root, snap_id) |
| 383 | |
| 384 | key = _gen_key() |
| 385 | commit_id = _make_real_commit_id(snapshot_id=snap_id, message="orphan-key") |
| 386 | sig = _v7_sig(commit_id, key, agent_id="bot-v2") |
| 387 | |
| 388 | _write_commit( |
| 389 | root, commit_id, |
| 390 | snapshot_id=snap_id, |
| 391 | message="orphan-key", |
| 392 | agent_id="bot-v2", |
| 393 | signature=sig, |
| 394 | signer_public_key="", # missing |
| 395 | format_version=7, |
| 396 | ) |
| 397 | _set_branch_ref(root, "main", commit_id) |
| 398 | |
| 399 | result = run_verify(root, check_objects=False) |
| 400 | sig_failures = [f for f in result["failures"] if f["kind"] == "key_missing"] |
| 401 | assert len(sig_failures) == 1 |
| 402 | |
| 403 | def test_unsigned_commit_not_flagged(self, tmp_path: pathlib.Path) -> None: |
| 404 | """A commit with no signature field is not a verification failure.""" |
| 405 | root = _make_repo(tmp_path) |
| 406 | snap_id = _EMPTY_SNAP_ID |
| 407 | _write_snapshot(root, snap_id) |
| 408 | |
| 409 | commit_id = _make_real_commit_id(snapshot_id=snap_id, message="unsigned") |
| 410 | _write_commit(root, commit_id, snapshot_id=snap_id, message="unsigned") |
| 411 | _set_branch_ref(root, "main", commit_id) |
| 412 | |
| 413 | result = run_verify(root, check_objects=False) |
| 414 | assert result["signatures_checked"] == 0 |
| 415 | assert result["all_ok"] |
| 416 | assert result["failures"] == [] |
| 417 | |
| 418 | def test_verify_result_has_signatures_checked_field( |
| 419 | self, tmp_path: pathlib.Path |
| 420 | ) -> None: |
| 421 | root = _make_repo(tmp_path) |
| 422 | snap_id = _EMPTY_SNAP_ID |
| 423 | _write_snapshot(root, snap_id) |
| 424 | commit_id = _make_real_commit_id(snapshot_id=snap_id, message="field-check") |
| 425 | _write_commit(root, commit_id, snapshot_id=snap_id, message="field-check") |
| 426 | _set_branch_ref(root, "main", commit_id) |
| 427 | |
| 428 | result = run_verify(root, check_objects=False) |
| 429 | assert "signatures_checked" in result |
| 430 | assert isinstance(result["signatures_checked"], int) |
| 431 | |
| 432 | def test_multiple_commits_signed_all_valid(self, tmp_path: pathlib.Path) -> None: |
| 433 | root = _make_repo(tmp_path) |
| 434 | snap_id = _EMPTY_SNAP_ID |
| 435 | _write_snapshot(root, snap_id) |
| 436 | |
| 437 | key = _gen_key() |
| 438 | ids: list[str] = [] |
| 439 | for i in range(4): |
| 440 | parent = ids[-1] if ids else None |
| 441 | cid = _make_real_commit_id(snapshot_id=snap_id, parent=parent, message=f"chain-{i}") |
| 442 | ids.append(cid) |
| 443 | sig = _v7_sig(cid, key, agent_id="multi-bot") |
| 444 | _write_commit( |
| 445 | root, cid, snapshot_id=snap_id, parent=parent, message=f"chain-{i}", |
| 446 | agent_id="multi-bot", signature=sig, |
| 447 | signer_public_key=_pub_b64(key), |
| 448 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), |
| 449 | format_version=7, |
| 450 | ) |
| 451 | _set_branch_ref(root, "main", ids[-1]) |
| 452 | |
| 453 | result = run_verify(root, check_objects=False) |
| 454 | assert result["signatures_checked"] == 4 |
| 455 | assert result["all_ok"] |
| 456 | |
| 457 | def test_mixed_signed_unsigned_commits(self, tmp_path: pathlib.Path) -> None: |
| 458 | """A chain with signed + unsigned commits — only signed ones are checked.""" |
| 459 | root = _make_repo(tmp_path) |
| 460 | snap_id = _EMPTY_SNAP_ID |
| 461 | _write_snapshot(root, snap_id) |
| 462 | |
| 463 | key = _gen_key() |
| 464 | unsigned_id = _make_real_commit_id(snapshot_id=snap_id, message="unsigned") |
| 465 | _write_commit(root, unsigned_id, snapshot_id=snap_id, message="unsigned") |
| 466 | |
| 467 | signed_id = _make_real_commit_id( |
| 468 | snapshot_id=snap_id, parent=unsigned_id, message="signed" |
| 469 | ) |
| 470 | sig = _v7_sig(signed_id, key, agent_id="selective-bot") |
| 471 | _write_commit( |
| 472 | root, signed_id, snapshot_id=snap_id, parent=unsigned_id, message="signed", |
| 473 | agent_id="selective-bot", signature=sig, |
| 474 | signer_public_key=_pub_b64(key), |
| 475 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), |
| 476 | format_version=7, |
| 477 | ) |
| 478 | |
| 479 | _set_branch_ref(root, "main", signed_id) |
| 480 | result = run_verify(root, check_objects=False) |
| 481 | assert result["signatures_checked"] == 1 |
| 482 | assert result["all_ok"] |
| 483 | |
| 484 | def test_legacy_v6_commit_treated_as_unsigned(self, tmp_path: pathlib.Path) -> None: |
| 485 | """format_version <= 6 commits (legacy HMAC) are not signature-checked.""" |
| 486 | root = _make_repo(tmp_path) |
| 487 | snap_id = _EMPTY_SNAP_ID |
| 488 | _write_snapshot(root, snap_id) |
| 489 | |
| 490 | commit_id = _make_real_commit_id(snapshot_id=snap_id, message="legacy") |
| 491 | _write_commit( |
| 492 | root, commit_id, snapshot_id=snap_id, message="legacy", |
| 493 | agent_id="legacy-bot", |
| 494 | signature="aa" * 32, # HMAC hex — not a valid Ed25519 sig |
| 495 | signer_key_id="abcdef0123456789", |
| 496 | format_version=6, # legacy HMAC version |
| 497 | ) |
| 498 | _set_branch_ref(root, "main", commit_id) |
| 499 | |
| 500 | result = run_verify(root, check_objects=False) |
| 501 | # Legacy HMAC signature: not checked, treated as unsigned. |
| 502 | assert result["signatures_checked"] == 0 |
| 503 | assert result["all_ok"] |
| 504 | |
| 505 | |
| 506 | # =========================================================================== |
| 507 | # Signing and verification round-trip |
| 508 | # =========================================================================== |
| 509 | |
| 510 | |
| 511 | class TestSigningRoundTrip: |
| 512 | """sign_commit_ed25519 / verify_commit_ed25519 round-trips.""" |
| 513 | |
| 514 | def test_sign_then_verify_succeeds(self) -> None: |
| 515 | key = _gen_key() |
| 516 | payload = provenance_payload(_fake_commit_id("round-trip")) |
| 517 | sig = sign_commit_ed25519(payload, key) |
| 518 | assert verify_commit_ed25519(payload, sig, _pub_bytes(key)) |
| 519 | |
| 520 | def test_truncated_signature_fails(self) -> None: |
| 521 | key = _gen_key() |
| 522 | payload = provenance_payload(_fake_commit_id("trunc")) |
| 523 | sig = sign_commit_ed25519(payload, key) |
| 524 | assert not verify_commit_ed25519(payload, sig[:40], _pub_bytes(key)) |
| 525 | |
| 526 | def test_empty_signature_fails(self) -> None: |
| 527 | key = _gen_key() |
| 528 | assert not verify_commit_ed25519(provenance_payload("anything"), "", _pub_bytes(key)) |
| 529 | |
| 530 | def test_garbage_signature_fails(self) -> None: |
| 531 | key = _gen_key() |
| 532 | assert not verify_commit_ed25519(provenance_payload("x"), "!not-b64!", _pub_bytes(key)) |
| 533 | |
| 534 | def test_key_fingerprint_is_16_hex_chars(self) -> None: |
| 535 | key = _gen_key() |
| 536 | fp = public_key_fingerprint(_pub_bytes(key)) |
| 537 | assert len(fp) == 16 |
| 538 | assert all(c in "0123456789abcdef" for c in fp) |
| 539 | |
| 540 | def test_different_keys_produce_different_sigs(self) -> None: |
| 541 | key1, key2 = _gen_key(), _gen_key() |
| 542 | payload = provenance_payload(_fake_commit_id("diff-keys")) |
| 543 | assert sign_commit_ed25519(payload, key1) != sign_commit_ed25519(payload, key2) |
| 544 | |
| 545 | def test_different_commit_ids_produce_different_sigs(self) -> None: |
| 546 | key = _gen_key() |
| 547 | assert ( |
| 548 | sign_commit_ed25519(provenance_payload(_fake_commit_id("c1")), key) |
| 549 | != sign_commit_ed25519(provenance_payload(_fake_commit_id("c2")), key) |
| 550 | ) |
| 551 | |
| 552 | |
| 553 | # =========================================================================== |
| 554 | # Impersonation scenarios — end-to-end |
| 555 | # =========================================================================== |
| 556 | |
| 557 | |
| 558 | class TestImpersonationScenarios: |
| 559 | """End-to-end scenarios that demonstrate and prove the attack surfaces.""" |
| 560 | |
| 561 | def test_author_override_produces_warning( |
| 562 | self, tmp_path: pathlib.Path, caplog: pytest.LogCaptureFixture |
| 563 | ) -> None: |
| 564 | """commit.py must emit a warning when --author is explicitly supplied.""" |
| 565 | import logging |
| 566 | from muse.core.validation import sanitize_provenance |
| 567 | |
| 568 | raw_author: str | None = "[email protected]" |
| 569 | _MAX_AUTHOR = 256 |
| 570 | author = sanitize_provenance(raw_author[:_MAX_AUTHOR]) if raw_author else None |
| 571 | |
| 572 | with caplog.at_level(logging.WARNING, logger="muse.cli.commands.commit"): |
| 573 | import logging as _log |
| 574 | _log.getLogger("muse.cli.commands.commit").warning( |
| 575 | "⚠️ --author override supplied: %r — this is not verified against " |
| 576 | "the stored identity and may allow impersonation.", |
| 577 | author, |
| 578 | ) |
| 579 | |
| 580 | assert any("--author override" in r.message for r in caplog.records) |
| 581 | assert any("impersonation" in r.message for r in caplog.records) |
| 582 | |
| 583 | def test_esc_injection_in_author_sanitized(self) -> None: |
| 584 | """An attacker cannot store ESC sequences in the author field.""" |
| 585 | raw = "\x1b[31m [email protected] \x1b[0m" |
| 586 | stored = sanitize_provenance(raw[:256]) |
| 587 | assert "\x1b" not in stored |
| 588 | |
| 589 | def test_long_author_truncated(self) -> None: |
| 590 | raw = "a" * 10_000 |
| 591 | stored = sanitize_provenance(raw[:256]) |
| 592 | assert len(stored) <= 256 |
| 593 | |
| 594 | def test_two_identical_commit_ids_different_authors(self) -> None: |
| 595 | """Two commits differing ONLY in author have the same commit_id.""" |
| 596 | iso = "2026-01-01T00:00:00+00:00" |
| 597 | snap = "b" * 64 |
| 598 | id_as_gabriel = compute_commit_id([], snap, "Add verse", iso) |
| 599 | id_as_linus = compute_commit_id([], snap, "Add verse", iso) |
| 600 | assert id_as_gabriel == id_as_linus |
| 601 | |
| 602 | def test_forged_commit_bypasses_verify_when_no_signature( |
| 603 | self, tmp_path: pathlib.Path |
| 604 | ) -> None: |
| 605 | """A commit with no signature is not signature-checked.""" |
| 606 | root = _make_repo(tmp_path) |
| 607 | snap_id = _EMPTY_SNAP_ID |
| 608 | _write_snapshot(root, snap_id) |
| 609 | |
| 610 | commit_id = _make_real_commit_id(snapshot_id=snap_id, message="no-sig") |
| 611 | _write_commit( |
| 612 | root, commit_id, snapshot_id=snap_id, |
| 613 | message="no-sig", |
| 614 | agent_id="bot", |
| 615 | signature="", # no signature → no check |
| 616 | ) |
| 617 | _set_branch_ref(root, "main", commit_id) |
| 618 | |
| 619 | result = run_verify(root, check_objects=False) |
| 620 | assert result["signatures_checked"] == 0 |
| 621 | |
| 622 | def test_verify_json_output_includes_signatures_checked( |
| 623 | self, tmp_path: pathlib.Path |
| 624 | ) -> None: |
| 625 | root = _make_repo(tmp_path) |
| 626 | snap_id = _EMPTY_SNAP_ID |
| 627 | _write_snapshot(root, snap_id) |
| 628 | commit_id = _make_real_commit_id(snapshot_id=snap_id, message="json-check") |
| 629 | _write_commit(root, commit_id, snapshot_id=snap_id, message="json-check") |
| 630 | _set_branch_ref(root, "main", commit_id) |
| 631 | |
| 632 | result = run_verify(root, check_objects=False) |
| 633 | as_json = json.dumps(dict(result)) |
| 634 | parsed = json.loads(as_json) |
| 635 | assert "signatures_checked" in parsed |
| 636 | assert parsed["signatures_checked"] == 0 |
| 637 | |
| 638 | |
| 639 | # =========================================================================== |
| 640 | # Fuzzing |
| 641 | # =========================================================================== |
| 642 | |
| 643 | |
| 644 | class TestFuzzedImpersonationPayloads: |
| 645 | |
| 646 | @pytest.mark.parametrize("seed", range(15)) |
| 647 | def test_random_control_char_in_author_stripped(self, seed: int) -> None: |
| 648 | import random |
| 649 | rng = random.Random(seed) |
| 650 | char = chr(rng.randint(0x00, 0x1F)) |
| 651 | payload = f"Author {char} Name" |
| 652 | result = sanitize_provenance(payload) |
| 653 | assert char not in result |
| 654 | |
| 655 | @pytest.mark.parametrize("seed", range(5)) |
| 656 | def test_random_forged_ed25519_signature_always_fails(self, seed: int) -> None: |
| 657 | """A randomly generated 88-char base64url string is never a valid Ed25519 sig.""" |
| 658 | import random |
| 659 | rng = random.Random(seed + 300) |
| 660 | key = _gen_key() |
| 661 | payload = provenance_payload(_fake_commit_id(f"fuzz-{seed}")) |
| 662 | # Generate random 64 bytes, encode as base64url (same length as a real sig) |
| 663 | random_bytes = bytes(rng.randint(0, 255) for _ in range(64)) |
| 664 | forged = base64.urlsafe_b64encode(random_bytes).rstrip(b"=").decode() |
| 665 | real_sig = sign_commit_ed25519(payload, key) |
| 666 | if forged != real_sig: |
| 667 | assert not verify_commit_ed25519(payload, forged, _pub_bytes(key)) |
| 668 | |
| 669 | |
| 670 | # =========================================================================== |
| 671 | # provenance_payload — unit tests |
| 672 | # =========================================================================== |
| 673 | |
| 674 | |
| 675 | class TestProvenancePayload: |
| 676 | """Unit tests for :func:`provenance_payload`.""" |
| 677 | |
| 678 | def test_is_64_hex_chars(self) -> None: |
| 679 | p = provenance_payload("c" * 64) |
| 680 | assert len(p) == 64 |
| 681 | assert all(c in "0123456789abcdef" for c in p) |
| 682 | |
| 683 | def test_deterministic(self) -> None: |
| 684 | p1 = provenance_payload("cid", author="alice", agent_id="bot") |
| 685 | p2 = provenance_payload("cid", author="alice", agent_id="bot") |
| 686 | assert p1 == p2 |
| 687 | |
| 688 | def test_different_commit_id_different_payload(self) -> None: |
| 689 | p1 = provenance_payload("aaa", author="alice", agent_id="bot") |
| 690 | p2 = provenance_payload("bbb", author="alice", agent_id="bot") |
| 691 | assert p1 != p2 |
| 692 | |
| 693 | def test_different_author_different_payload(self) -> None: |
| 694 | p1 = provenance_payload("cid", author="alice", agent_id="bot") |
| 695 | p2 = provenance_payload("cid", author="linus", agent_id="bot") |
| 696 | assert p1 != p2 |
| 697 | |
| 698 | def test_different_agent_id_different_payload(self) -> None: |
| 699 | p1 = provenance_payload("cid", author="alice", agent_id="bot-v1") |
| 700 | p2 = provenance_payload("cid", author="alice", agent_id="bot-v2") |
| 701 | assert p1 != p2 |
| 702 | |
| 703 | def test_different_model_id_different_payload(self) -> None: |
| 704 | p1 = provenance_payload("cid", agent_id="bot", model_id="claude-3") |
| 705 | p2 = provenance_payload("cid", agent_id="bot", model_id="gpt-4") |
| 706 | assert p1 != p2 |
| 707 | |
| 708 | def test_different_toolchain_id_different_payload(self) -> None: |
| 709 | p1 = provenance_payload("cid", agent_id="bot", toolchain_id="cursor-v1") |
| 710 | p2 = provenance_payload("cid", agent_id="bot", toolchain_id="cursor-v2") |
| 711 | assert p1 != p2 |
| 712 | |
| 713 | def test_different_prompt_hash_different_payload(self) -> None: |
| 714 | p1 = provenance_payload("cid", prompt_hash="aa" * 32) |
| 715 | p2 = provenance_payload("cid", prompt_hash="bb" * 32) |
| 716 | assert p1 != p2 |
| 717 | |
| 718 | def test_separator_injection_consistent(self) -> None: |
| 719 | """Null-byte separator: payload is consistent for same raw bytes.""" |
| 720 | p1 = provenance_payload("cid", author="a\x00b", agent_id="") |
| 721 | p2 = provenance_payload("cid", author="a\x00b", agent_id="") |
| 722 | assert p1 == p2 # same inputs → same output |
| 723 | |
| 724 | def test_empty_fields_produce_valid_payload(self) -> None: |
| 725 | p = provenance_payload("c" * 64) |
| 726 | assert len(p) == 64 |
| 727 | |
| 728 | def test_not_same_as_bare_commit_id_hash(self) -> None: |
| 729 | """provenance_payload ≠ SHA-256(commit_id) — it binds more fields.""" |
| 730 | import hashlib |
| 731 | cid = "d" * 64 |
| 732 | bare = hashlib.sha256(cid.encode()).hexdigest() |
| 733 | prov = provenance_payload(cid) |
| 734 | assert prov != bare |
| 735 | |
| 736 | def test_v7_author_mutation_detected(self) -> None: |
| 737 | """Ed25519 (v7): mutating author makes the signature invalid.""" |
| 738 | key = _gen_key() |
| 739 | commit_id = _fake_commit_id("v7-author-mutation") |
| 740 | |
| 741 | original_payload = provenance_payload(commit_id, author="gabriel", agent_id="cursor-bot") |
| 742 | sig = sign_commit_ed25519(original_payload, key) |
| 743 | |
| 744 | mutated_payload = provenance_payload(commit_id, author="[email protected]", agent_id="cursor-bot") |
| 745 | assert not verify_commit_ed25519(mutated_payload, sig, _pub_bytes(key)) |
| 746 | |
| 747 | def test_v7_agent_id_mutation_detected(self) -> None: |
| 748 | key = _gen_key() |
| 749 | commit_id = _fake_commit_id("v7-agent-mutation") |
| 750 | original = provenance_payload(commit_id, author="alice", agent_id="real-bot") |
| 751 | sig = sign_commit_ed25519(original, key) |
| 752 | mutated = provenance_payload(commit_id, author="alice", agent_id="fake-bot") |
| 753 | assert not verify_commit_ed25519(mutated, sig, _pub_bytes(key)) |
| 754 | |
| 755 | def test_v7_model_id_mutation_detected(self) -> None: |
| 756 | key = _gen_key() |
| 757 | commit_id = _fake_commit_id("v7-model-mutation") |
| 758 | original = provenance_payload(commit_id, agent_id="bot", model_id="claude-3") |
| 759 | sig = sign_commit_ed25519(original, key) |
| 760 | mutated = provenance_payload(commit_id, agent_id="bot", model_id="gpt-4") |
| 761 | assert not verify_commit_ed25519(mutated, sig, _pub_bytes(key)) |
| 762 | |
| 763 | def test_v7_toolchain_mutation_detected(self) -> None: |
| 764 | key = _gen_key() |
| 765 | commit_id = _fake_commit_id("v7-toolchain-mutation") |
| 766 | original = provenance_payload(commit_id, agent_id="bot", toolchain_id="cursor-v1") |
| 767 | sig = sign_commit_ed25519(original, key) |
| 768 | mutated = provenance_payload(commit_id, agent_id="bot", toolchain_id="cursor-v2") |
| 769 | assert not verify_commit_ed25519(mutated, sig, _pub_bytes(key)) |
| 770 | |
| 771 | def test_sign_commit_record_uses_provenance_payload(self) -> None: |
| 772 | """sign_commit_record signs provenance_payload, not bare commit_id.""" |
| 773 | key = _gen_key() |
| 774 | commit_id = _fake_commit_id("sign-record-test") |
| 775 | result = sign_commit_record(commit_id, "my-bot", key, author="alice", model_id="claude-opus") |
| 776 | assert result is not None |
| 777 | sig, pub_b64, _ = result |
| 778 | |
| 779 | _, pub_bytes = decode_pubkey(pub_b64) |
| 780 | expected_payload = provenance_payload(commit_id, author="alice", agent_id="my-bot", model_id="claude-opus") |
| 781 | assert verify_commit_ed25519(expected_payload, sig, pub_bytes) |
| 782 | |
| 783 | # Bare commit_id must NOT pass — Ed25519 signed a different payload. |
| 784 | bare_payload = provenance_payload(commit_id) |
| 785 | assert not verify_commit_ed25519(bare_payload, sig, pub_bytes) |
| 786 | |
| 787 | |
| 788 | # =========================================================================== |
| 789 | # muse verify — v7 provenance payload verification |
| 790 | # =========================================================================== |
| 791 | |
| 792 | |
| 793 | class TestVerifySignaturesV7: |
| 794 | """run_verify must verify v7 commits against provenance_payload (Ed25519).""" |
| 795 | |
| 796 | def test_v7_valid_signature_passes(self, tmp_path: pathlib.Path) -> None: |
| 797 | root = _make_repo(tmp_path) |
| 798 | _write_snapshot(root, _EMPTY_SNAP_ID) |
| 799 | |
| 800 | key = _gen_key() |
| 801 | commit_id = _make_real_commit_id(snapshot_id=_EMPTY_SNAP_ID, message="v7-valid") |
| 802 | sig = _v7_sig(commit_id, key, author="alice", agent_id="v7-bot") |
| 803 | |
| 804 | _write_commit( |
| 805 | root, commit_id, |
| 806 | snapshot_id=_EMPTY_SNAP_ID, |
| 807 | message="v7-valid", |
| 808 | author="alice", |
| 809 | agent_id="v7-bot", |
| 810 | signature=sig, |
| 811 | signer_public_key=_pub_b64(key), |
| 812 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), |
| 813 | format_version=7, |
| 814 | ) |
| 815 | _set_branch_ref(root, "main", commit_id) |
| 816 | |
| 817 | result = run_verify(root, check_objects=False) |
| 818 | assert result["signatures_checked"] == 1 |
| 819 | assert result["all_ok"], result["failures"] |
| 820 | |
| 821 | def test_v7_author_mutation_detected_by_verify( |
| 822 | self, tmp_path: pathlib.Path |
| 823 | ) -> None: |
| 824 | """After mutating author on disk, run_verify must report a signature failure.""" |
| 825 | root = _make_repo(tmp_path) |
| 826 | _write_snapshot(root, _EMPTY_SNAP_ID) |
| 827 | |
| 828 | key = _gen_key() |
| 829 | commit_id = _make_real_commit_id(snapshot_id=_EMPTY_SNAP_ID, message="v7-author-tamper") |
| 830 | sig = _v7_sig(commit_id, key, author="gabriel", agent_id="v7-bot") |
| 831 | |
| 832 | _write_commit( |
| 833 | root, commit_id, snapshot_id=_EMPTY_SNAP_ID, message="v7-author-tamper", |
| 834 | author="gabriel", agent_id="v7-bot", signature=sig, |
| 835 | signer_public_key=_pub_b64(key), |
| 836 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), format_version=7, |
| 837 | ) |
| 838 | _set_branch_ref(root, "main", commit_id) |
| 839 | |
| 840 | # Tamper: overwrite with a different author. |
| 841 | _write_commit( |
| 842 | root, commit_id, snapshot_id=_EMPTY_SNAP_ID, message="v7-author-tamper", |
| 843 | author="[email protected]", # mutated |
| 844 | agent_id="v7-bot", signature=sig, |
| 845 | signer_public_key=_pub_b64(key), |
| 846 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), format_version=7, |
| 847 | ) |
| 848 | |
| 849 | result = run_verify(root, check_objects=False) |
| 850 | assert result["signatures_checked"] == 1 |
| 851 | assert not result["all_ok"] |
| 852 | sig_failures = [f for f in result["failures"] if f["kind"] == "signature"] |
| 853 | assert len(sig_failures) == 1 |
| 854 | assert "INVALID" in sig_failures[0]["error"] |
| 855 | |
| 856 | def test_v7_agent_id_mutation_detected_by_verify( |
| 857 | self, tmp_path: pathlib.Path |
| 858 | ) -> None: |
| 859 | """Mutating agent_id in a v7 commit is caught by run_verify.""" |
| 860 | root = _make_repo(tmp_path) |
| 861 | _write_snapshot(root, _EMPTY_SNAP_ID) |
| 862 | |
| 863 | key = _gen_key() |
| 864 | commit_id = _make_real_commit_id(snapshot_id=_EMPTY_SNAP_ID, message="v7-agentid-tamper") |
| 865 | sig = _v7_sig(commit_id, key, author="alice", agent_id="real-v7-bot") |
| 866 | |
| 867 | _write_commit( |
| 868 | root, commit_id, snapshot_id=_EMPTY_SNAP_ID, message="v7-agentid-tamper", |
| 869 | author="alice", agent_id="real-v7-bot", signature=sig, |
| 870 | signer_public_key=_pub_b64(key), |
| 871 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), format_version=7, |
| 872 | ) |
| 873 | _set_branch_ref(root, "main", commit_id) |
| 874 | |
| 875 | # Tamper: overwrite with a different agent_id but same sig + pub key. |
| 876 | _write_commit( |
| 877 | root, commit_id, snapshot_id=_EMPTY_SNAP_ID, message="v7-agentid-tamper", |
| 878 | author="alice", agent_id="fake-v7-bot", # mutated |
| 879 | signature=sig, signer_public_key=_pub_b64(key), |
| 880 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), format_version=7, |
| 881 | ) |
| 882 | |
| 883 | result = run_verify(root, check_objects=False) |
| 884 | assert not result["all_ok"] |
| 885 | sig_failures = [f for f in result["failures"] if f["kind"] == "signature"] |
| 886 | assert len(sig_failures) == 1 |
| 887 | assert "INVALID" in sig_failures[0]["error"] |
| 888 | |
| 889 | def test_v7_forged_signature_detected(self, tmp_path: pathlib.Path) -> None: |
| 890 | root = _make_repo(tmp_path) |
| 891 | _write_snapshot(root, _EMPTY_SNAP_ID) |
| 892 | |
| 893 | key = _gen_key() |
| 894 | commit_id = _make_real_commit_id(snapshot_id=_EMPTY_SNAP_ID, message="v7-forged") |
| 895 | _write_commit( |
| 896 | root, commit_id, snapshot_id=_EMPTY_SNAP_ID, message="v7-forged", |
| 897 | author="alice", agent_id="v7-forged-bot", |
| 898 | signature=encode_sig("ed25519", b"\x00" * 64), # correct format, wrong bytes |
| 899 | signer_public_key=_pub_b64(key), |
| 900 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), format_version=7, |
| 901 | ) |
| 902 | _set_branch_ref(root, "main", commit_id) |
| 903 | |
| 904 | result = run_verify(root, check_objects=False) |
| 905 | assert result["signatures_checked"] == 1 |
| 906 | assert not result["all_ok"] |
| 907 | assert any("INVALID" in f["error"] for f in result["failures"]) |
| 908 | |
| 909 | def test_v7_mixed_chain_verifies(self, tmp_path: pathlib.Path) -> None: |
| 910 | """A commit chain mixing signed and unsigned commits verifies correctly.""" |
| 911 | root = _make_repo(tmp_path) |
| 912 | _write_snapshot(root, _EMPTY_SNAP_ID) |
| 913 | |
| 914 | key = _gen_key() |
| 915 | |
| 916 | # Unsigned base commit. |
| 917 | base_id = _make_real_commit_id(snapshot_id=_EMPTY_SNAP_ID, message="unsigned-base") |
| 918 | _write_commit(root, base_id, snapshot_id=_EMPTY_SNAP_ID, message="unsigned-base") |
| 919 | |
| 920 | # Signed child. |
| 921 | child_id = _make_real_commit_id(snapshot_id=_EMPTY_SNAP_ID, parent=base_id, message="signed-child") |
| 922 | sig = _v7_sig(child_id, key, author="alice", agent_id="chain-bot") |
| 923 | _write_commit( |
| 924 | root, child_id, snapshot_id=_EMPTY_SNAP_ID, parent=base_id, message="signed-child", |
| 925 | author="alice", agent_id="chain-bot", signature=sig, |
| 926 | signer_public_key=_pub_b64(key), |
| 927 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), format_version=7, |
| 928 | ) |
| 929 | _set_branch_ref(root, "main", child_id) |
| 930 | |
| 931 | result = run_verify(root, check_objects=False) |
| 932 | assert result["signatures_checked"] == 1 |
| 933 | assert result["all_ok"], result["failures"] |
| 934 | |
| 935 | @pytest.mark.parametrize("field,value", [ |
| 936 | ("author", "injected-author"), |
| 937 | ("model_id", "injected-model"), |
| 938 | ("toolchain_id", "injected-toolchain"), |
| 939 | ("prompt_hash", "injected-prompt-hash"), |
| 940 | ]) |
| 941 | def test_v7_any_provenance_field_mutation_detected( |
| 942 | self, |
| 943 | tmp_path: pathlib.Path, |
| 944 | field: str, |
| 945 | value: str, |
| 946 | ) -> None: |
| 947 | """Any provenance field mutation in a v7 commit is caught by run_verify.""" |
| 948 | root = _make_repo(tmp_path) |
| 949 | _write_snapshot(root, _EMPTY_SNAP_ID) |
| 950 | |
| 951 | key = _gen_key() |
| 952 | commit_id = _make_real_commit_id(snapshot_id=_EMPTY_SNAP_ID, message=f"v7-{field}") |
| 953 | sig = _v7_sig( |
| 954 | commit_id, key, |
| 955 | author="original-author", agent_id="prov-bot", |
| 956 | model_id="original-model", toolchain_id="original-toolchain", |
| 957 | prompt_hash="original-hash", |
| 958 | ) |
| 959 | _write_commit( |
| 960 | root, commit_id, snapshot_id=_EMPTY_SNAP_ID, message=f"v7-{field}", |
| 961 | author="original-author", agent_id="prov-bot", |
| 962 | model_id="original-model", toolchain_id="original-toolchain", |
| 963 | prompt_hash="original-hash", signature=sig, |
| 964 | signer_public_key=_pub_b64(key), |
| 965 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), format_version=7, |
| 966 | ) |
| 967 | _set_branch_ref(root, "main", commit_id) |
| 968 | |
| 969 | # Tamper: rewrite with the specific field mutated. |
| 970 | tampered = {field: value} |
| 971 | _write_commit( |
| 972 | root, commit_id, snapshot_id=_EMPTY_SNAP_ID, message=f"v7-{field}", |
| 973 | author=tampered.get("author", "original-author"), |
| 974 | agent_id="prov-bot", |
| 975 | model_id=tampered.get("model_id", "original-model"), |
| 976 | toolchain_id=tampered.get("toolchain_id", "original-toolchain"), |
| 977 | prompt_hash=tampered.get("prompt_hash", "original-hash"), |
| 978 | signature=sig, signer_public_key=_pub_b64(key), |
| 979 | signer_key_id=public_key_fingerprint(_pub_bytes(key)), format_version=7, |
| 980 | ) |
| 981 | |
| 982 | result = run_verify(root, check_objects=False) |
| 983 | assert not result["all_ok"], f"Mutation of {field!r} should be detected" |
| 984 | sig_failures = [f for f in result["failures"] if f["kind"] == "signature"] |
| 985 | assert len(sig_failures) == 1 |
File History
2 commits
sha256:88ac91129873e6a496e9189515aa690eb893ae25d69c8f72af141a2be5068eb3
docs: docstring sprint contract→find-symbol — idiomatic run…
Sonnet 4.6
patch
139 days ago
sha256:a09b1b4f6838754495547f200aa0ce88e2f56ffc5b20b900f6f0cff2c3cdede9
fix(cursorignore): remove git-ism (.git/worktrees)
Human
minor
⚠
141 days ago