tests/test_update_chain.py
| 1 | """Tests for UpdateChain.""" |
| 2 | |
| 3 | from __future__ import annotations |
| 4 | |
| 5 | import pytest |
| 6 | |
| 7 | from pqc_bootloader.errors import FirmwareRollbackError, UpdateChainError |
| 8 | from pqc_bootloader.firmware import FirmwareImage, FirmwareMetadata, TargetDevice |
| 9 | from pqc_bootloader.signer import FirmwareSigner |
| 10 | from pqc_bootloader.update_chain import UpdateChain |
| 11 | |
| 12 | |
| 13 | def _fw(version: str, payload: bytes, name: str = "acme-inference-os") -> FirmwareImage: |
| 14 | meta = FirmwareMetadata( |
| 15 | name=name, |
| 16 | version=version, |
| 17 | target=TargetDevice.AI_INFERENCE_APPLIANCE, |
| 18 | ) |
| 19 | return FirmwareImage.from_bytes(meta, payload) |
| 20 | |
| 21 | |
| 22 | def test_add_first_link_ok(firmware_signer: FirmwareSigner) -> None: |
| 23 | chain = UpdateChain() |
| 24 | fw = _fw("1.0.0", b"v1 payload") |
| 25 | signed = firmware_signer.sign(fw) |
| 26 | chain.add(signed) |
| 27 | assert chain.current() is signed |
| 28 | ok, errors = chain.verify_chain() |
| 29 | assert ok and errors == [] |
| 30 | |
| 31 | |
| 32 | def test_second_link_verifies_previous_hash(firmware_signer: FirmwareSigner) -> None: |
| 33 | chain = UpdateChain() |
| 34 | v1 = firmware_signer.sign(_fw("1.0.0", b"v1 payload")) |
| 35 | v2 = firmware_signer.sign( |
| 36 | _fw("1.1.0", b"v2 payload"), |
| 37 | previous_firmware_hash=v1.firmware.image_hash, |
| 38 | ) |
| 39 | chain.add(v1) |
| 40 | chain.add(v2) |
| 41 | ok, errors = chain.verify_chain() |
| 42 | assert ok and errors == [] |
| 43 | |
| 44 | |
| 45 | def test_mismatched_previous_hash_raises(firmware_signer: FirmwareSigner) -> None: |
| 46 | chain = UpdateChain() |
| 47 | v1 = firmware_signer.sign(_fw("1.0.0", b"v1 payload")) |
| 48 | v2 = firmware_signer.sign( |
| 49 | _fw("1.1.0", b"v2 payload"), |
| 50 | previous_firmware_hash="de" * 32, # wrong |
| 51 | ) |
| 52 | chain.add(v1) |
| 53 | with pytest.raises(UpdateChainError): |
| 54 | chain.add(v2) |
| 55 | |
| 56 | |
| 57 | def test_rollback_blocked_by_default(firmware_signer: FirmwareSigner) -> None: |
| 58 | chain = UpdateChain() |
| 59 | v1 = firmware_signer.sign(_fw("1.0.0", b"v1 payload")) |
| 60 | v0 = firmware_signer.sign( |
| 61 | _fw("0.9.0", b"v0 payload"), |
| 62 | previous_firmware_hash=v1.firmware.image_hash, |
| 63 | ) |
| 64 | chain.add(v1) |
| 65 | with pytest.raises(FirmwareRollbackError): |
| 66 | chain.add(v0) |
| 67 | |
| 68 | |
| 69 | def test_rollback_allowed_when_flag_set(firmware_signer: FirmwareSigner) -> None: |
| 70 | chain = UpdateChain() |
| 71 | v1 = firmware_signer.sign(_fw("1.0.0", b"v1 payload")) |
| 72 | v0 = firmware_signer.sign( |
| 73 | _fw("0.9.0", b"v0 payload"), |
| 74 | previous_firmware_hash=v1.firmware.image_hash, |
| 75 | ) |
| 76 | chain.add(v1) |
| 77 | chain.add(v0, allow_rollback=True) |
| 78 | assert chain.current() is v0 |
| 79 | |