test_agent_key_fd_zeroing.py
python
sha256:81ae324db5ad375fbfe4834c6fcb378312cafad3cc92dec5d3e5c427306621a2
fix: remove commit_exists filter from have anchors — server…
Sonnet 4.6
patch
21 days ago
| 1 | """Tests for DerivedKey zeroing in get_signing_identity (MUSE_AGENT_KEY_FD path). |
| 2 | |
| 3 | get_signing_identity reads a 64-byte sub-seed from MUSE_AGENT_KEY_FD, calls |
| 4 | derive_identity_key() to produce a DerivedKey, creates the Ed25519 private |
| 5 | key from it, then zeros the sub_seed bytearray. But it did NOT call |
| 6 | dk.zero() — leaving the DerivedKey's 32-byte private_bytes and chain_code in |
| 7 | heap memory indefinitely. |
| 8 | |
| 9 | Fix: |
| 10 | - Call dk.zero() immediately after Ed25519PrivateKey.from_private_bytes(). |
| 11 | - The Ed25519 key object holds the key material; the DerivedKey is no |
| 12 | longer needed and must be wiped. |
| 13 | |
| 14 | Coverage |
| 15 | -------- |
| 16 | I DerivedKey is zeroed after get_signing_identity returns (MUSE_AGENT_KEY_FD) |
| 17 | I1 private_bytes is all-zero in the DerivedKey after signing identity resolved |
| 18 | I2 chain_code is all-zero in the DerivedKey after signing identity resolved |
| 19 | """ |
| 20 | |
| 21 | from __future__ import annotations |
| 22 | |
| 23 | import os |
| 24 | from unittest.mock import patch |
| 25 | |
| 26 | import pytest |
| 27 | |
| 28 | from muse.core import hdkeys as _hdkeys |
| 29 | from muse.core.slip010 import DerivedKey |
| 30 | from muse.core.bip39 import mnemonic_to_seed |
| 31 | from muse.core.hdkeys import derive_agent_sub_seed, DOMAIN_IDENTITY |
| 32 | from muse.cli import config as config_mod |
| 33 | |
| 34 | _MNEMONIC = ( |
| 35 | "abandon abandon abandon abandon abandon abandon abandon abandon " |
| 36 | "abandon abandon abandon about" |
| 37 | ) |
| 38 | _SEED = mnemonic_to_seed(_MNEMONIC) |
| 39 | _SUB_SEED = derive_agent_sub_seed(_SEED, domain=DOMAIN_IDENTITY, agent_id=0) |
| 40 | |
| 41 | |
| 42 | class TestAgentKeyFdDerivedKeyZeroed: |
| 43 | def _make_fd(self) -> int: |
| 44 | """Create a pipe and write 64 bytes of sub-seed; return the read end fd.""" |
| 45 | r, w = os.pipe() |
| 46 | os.write(w, bytes(_SUB_SEED)) |
| 47 | os.close(w) |
| 48 | return r |
| 49 | |
| 50 | def test_I1_private_bytes_zeroed_after_fd_read(self, monkeypatch: pytest.MonkeyPatch) -> None: |
| 51 | """I1: DerivedKey.private_bytes is zeroed after the signing identity is resolved.""" |
| 52 | captured: list[DerivedKey] = [] |
| 53 | original_derive = _hdkeys.derive_identity_key |
| 54 | |
| 55 | def capturing_derive(*args: int | bytes, **kwargs: int) -> DerivedKey: |
| 56 | dk = original_derive(*args, **kwargs) |
| 57 | captured.append(dk) |
| 58 | return dk |
| 59 | |
| 60 | r_fd = self._make_fd() |
| 61 | monkeypatch.setenv("MUSE_AGENT_KEY_FD", str(r_fd)) |
| 62 | monkeypatch.setenv("MUSE_AGENT_HANDLE", "test-agent") |
| 63 | |
| 64 | with patch.object(_hdkeys, "derive_identity_key", side_effect=capturing_derive): |
| 65 | config_mod.get_signing_identity() |
| 66 | |
| 67 | assert captured, "derive_identity_key was not called via MUSE_AGENT_KEY_FD path" |
| 68 | dk = captured[0] |
| 69 | assert dk.private_bytes == bytearray(32), ( |
| 70 | "DerivedKey.private_bytes must be zeroed after get_signing_identity returns" |
| 71 | ) |
| 72 | |
| 73 | def test_I2_chain_code_zeroed_after_fd_read(self, monkeypatch: pytest.MonkeyPatch) -> None: |
| 74 | """I2: DerivedKey.chain_code is zeroed after the signing identity is resolved.""" |
| 75 | captured: list[DerivedKey] = [] |
| 76 | original_derive = _hdkeys.derive_identity_key |
| 77 | |
| 78 | def capturing_derive(*args: int | bytes, **kwargs: int) -> DerivedKey: |
| 79 | dk = original_derive(*args, **kwargs) |
| 80 | captured.append(dk) |
| 81 | return dk |
| 82 | |
| 83 | r_fd = self._make_fd() |
| 84 | monkeypatch.setenv("MUSE_AGENT_KEY_FD", str(r_fd)) |
| 85 | monkeypatch.setenv("MUSE_AGENT_HANDLE", "test-agent") |
| 86 | |
| 87 | with patch.object(_hdkeys, "derive_identity_key", side_effect=capturing_derive): |
| 88 | config_mod.get_signing_identity() |
| 89 | |
| 90 | assert captured, "derive_identity_key was not called via MUSE_AGENT_KEY_FD path" |
| 91 | dk = captured[0] |
| 92 | assert dk.chain_code == bytearray(32), ( |
| 93 | "DerivedKey.chain_code must be zeroed after get_signing_identity returns" |
| 94 | ) |
File History
4 commits
sha256:81ae324db5ad375fbfe4834c6fcb378312cafad3cc92dec5d3e5c427306621a2
fix: remove commit_exists filter from have anchors — server…
Sonnet 4.6
patch
21 days ago
sha256:36c3cb3e76619d4c30a6d9bf81b5ec4ff148e30dcfed913e3114ca7b43b81c7e
fix: rename objects→blobs in push client and all stale test…
Sonnet 4.6
patch
22 days ago
sha256:c06a9b9b9fee26c68ea725b44d54b2c0a171301ce9de746d5b656617b4463a9a
fix: repair four test failures from post-migration audit
Sonnet 4.6
patch
29 days ago
sha256:1900655993c83c4107067375548a7be823e471d2515830842f1a12cba4bd3cdf
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Sonnet 4.6
minor
⚠
29 days ago