def test_generic_read(self):
for metadata, inner_metadata_cls in [('snapshot', Snapshot),
('timestamp', Timestamp),
('targets', Targets)]:
# Load JSON-formatted metdata of each supported type from file
# and from out-of-band read JSON string
path = os.path.join(self.repo_dir, 'metadata', metadata + '.json')
metadata_obj = Metadata.from_file(path)
with open(path, 'rb') as f:
metadata_str = f.read()
metadata_obj2 = JSONDeserializer().deserialize(metadata_str)
# Assert that both methods instantiate the right inner class for
# each metadata type and ...
self.assertTrue(isinstance(metadata_obj.signed,
inner_metadata_cls))
self.assertTrue(
isinstance(metadata_obj2.signed, inner_metadata_cls))
# ... and return the same object (compared by dict representation)
self.assertDictEqual(metadata_obj.to_dict(),
metadata_obj2.to_dict())
# Assert that it chokes correctly on an unknown metadata type
bad_metadata_path = 'bad-metadata.json'
bad_metadata = {'signed': {'_type': 'bad-metadata'}}
with open(bad_metadata_path, 'wb') as f:
f.write(json.dumps(bad_metadata).encode('utf-8'))
with self.assertRaises(DeserializationError):
Metadata.from_file(bad_metadata_path)
os.remove(bad_metadata_path)
def test_md_read_write_file_exceptions(self) -> None:
# Test writing to a file with bad filename
with self.assertRaises(exceptions.StorageError):
Metadata.from_file("bad-metadata.json")
# Test serializing to a file with bad filename
with self.assertRaises(exceptions.StorageError):
md = Metadata.from_file(
os.path.join(self.repo_dir, "metadata", "root.json"))
md.to_file("")
def test_read_write_read_compare(self) -> None:
for metadata in TOP_LEVEL_ROLE_NAMES:
path = os.path.join(self.repo_dir, "metadata", metadata + ".json")
md_obj = Metadata.from_file(path)
path_2 = path + ".tmp"
md_obj.to_file(path_2)
md_obj_2 = Metadata.from_file(path_2)
self.assertDictEqual(md_obj.to_dict(), md_obj_2.to_dict())
os.remove(path_2)
def test_read_write_read_compare(self):
for metadata in ['snapshot', 'timestamp', 'targets']:
path = os.path.join(self.repo_dir, 'metadata', metadata + '.json')
metadata_obj = Metadata.from_file(path)
path_2 = path + '.tmp'
metadata_obj.to_file(path_2)
metadata_obj_2 = Metadata.from_file(path_2)
self.assertDictEqual(metadata_obj.to_dict(),
metadata_obj_2.to_dict())
os.remove(path_2)
def _initialize(self) -> None:
"""Setup a minimal valid repository."""
self.md_targets = Metadata(Targets(expires=self.safe_expiry))
self.md_snapshot = Metadata(Snapshot(expires=self.safe_expiry))
self.md_timestamp = Metadata(Timestamp(expires=self.safe_expiry))
self.md_root = Metadata(Root(expires=self.safe_expiry))
for role in TOP_LEVEL_ROLE_NAMES:
key, signer = self.create_key()
self.md_root.signed.add_key(key, role)
self.add_signer(role, signer)
self.publish_root()
def test_trusted_root_unsigned(self) -> None:
# Local trusted root is not signed
root_path = os.path.join(self.metadata_dir, "root.json")
md_root = Metadata.from_file(root_path)
md_root.signatures.clear()
md_root.to_file(root_path)
with self.assertRaises(UnsignedMetadataError):
self._run_refresh()
# The update failed, no changes in metadata
self._assert_files_exist([Root.type])
md_root_after = Metadata.from_file(root_path)
self.assertEqual(md_root.to_bytes(), md_root_after.to_bytes())
def _modify_repository_root(
self,
modification_func: Callable[[Metadata], None],
bump_version: bool = False,
) -> None:
"""Apply 'modification_func' to root and persist it."""
role_path = os.path.join(self.repository_directory, "metadata",
"root.json")
root = Metadata.from_file(role_path)
modification_func(root)
if bump_version:
root.signed.version += 1
root_key_path = os.path.join(self.keystore_directory, "root_key")
root_key_dict = import_rsa_privatekey_from_file(root_key_path,
password="******")
signer = SSlibSigner(root_key_dict)
root.sign(signer)
root.to_file(
os.path.join(self.repository_directory, "metadata", "root.json"))
root.to_file(
os.path.join(
self.repository_directory,
"metadata",
f"{root.signed.version}.root.json",
))
def serialize(self, metadata_obj: Metadata) -> bytes:
"""Serialize Metadata object into utf-8 encoded JSON bytes."""
try:
indent = None if self.compact else 1
separators = (",", ":") if self.compact else (",", ": ")
json_bytes = json.dumps(
metadata_obj.to_dict(),
indent=indent,
separators=separators,
sort_keys=True,
).encode("utf-8")
if self.validate:
try:
new_md_obj = JSONDeserializer().deserialize(json_bytes)
if metadata_obj != new_md_obj:
raise ValueError(
"Metadata changes if you serialize and deserialize."
)
except Exception as e:
raise ValueError("Metadata cannot be validated!") from e
except Exception as e:
raise SerializationError("Failed to serialize JSON") from e
return json_bytes
def test_serialize_with_validate(self) -> None:
# Assert that by changing one required attribute validation will fail.
root = Metadata.from_file(
os.path.join(self.repo_dir, "metadata", "root.json"))
root.signed.version = 0
with self.assertRaises(SerializationError):
root.to_bytes(JSONSerializer(validate=True))
def test_to_from_bytes(self) -> None:
for metadata in TOP_LEVEL_ROLE_NAMES:
path = os.path.join(self.repo_dir, "metadata", metadata + ".json")
with open(path, "rb") as f:
metadata_bytes = f.read()
md_obj = Metadata.from_bytes(metadata_bytes)
# Comparate that from_bytes/to_bytes doesn't change the content
# for two cases for the serializer: noncompact and compact.
# Case 1: test noncompact by overriding the default serializer.
self.assertEqual(md_obj.to_bytes(JSONSerializer()), metadata_bytes)
# Case 2: test compact by using the default serializer.
obj_bytes = md_obj.to_bytes()
metadata_obj_2 = Metadata.from_bytes(obj_bytes)
self.assertEqual(metadata_obj_2.to_bytes(), obj_bytes)
def test_metadata_signed_is_expired(self) -> None:
# Use of Snapshot is arbitrary, we're just testing the base class
# features with real data
snapshot_path = os.path.join(self.repo_dir, "metadata",
"snapshot.json")
md = Metadata.from_file(snapshot_path)
self.assertEqual(md.signed.expires, datetime(2030, 1, 1, 0, 0))
# Test is_expired with reference_time provided
is_expired = md.signed.is_expired(md.signed.expires)
self.assertTrue(is_expired)
is_expired = md.signed.is_expired(md.signed.expires +
timedelta(days=1))
self.assertTrue(is_expired)
is_expired = md.signed.is_expired(md.signed.expires -
timedelta(days=1))
self.assertFalse(is_expired)
# Test is_expired without reference_time,
# manipulating md.signed.expires
expires = md.signed.expires
md.signed.expires = datetime.utcnow()
is_expired = md.signed.is_expired()
self.assertTrue(is_expired)
md.signed.expires = datetime.utcnow() + timedelta(days=1)
is_expired = md.signed.is_expired()
self.assertFalse(is_expired)
md.signed.expires = expires
def test_update_root_new_root_cannot_be_verified_with_threshold(self):
# new_root data with threshold which cannot be verified.
root = Metadata.from_bytes(self.metadata["root"])
# remove root role keyids representing root signatures
root.signed.roles["root"].keyids = []
with self.assertRaises(exceptions.UnsignedMetadataError):
self.trusted_set.update_root(root.to_bytes())
def test_metadata_timestamp(self):
timestamp_path = os.path.join(
self.repo_dir, 'metadata', 'timestamp.json')
timestamp = Metadata.from_file(timestamp_path)
self.assertEqual(timestamp.signed.version, 1)
timestamp.signed.bump_version()
self.assertEqual(timestamp.signed.version, 2)
self.assertEqual(timestamp.signed.expires, datetime(2030, 1, 1, 0, 0))
timestamp.signed.bump_expiration()
self.assertEqual(timestamp.signed.expires, datetime(2030, 1, 2, 0, 0))
timestamp.signed.bump_expiration(timedelta(days=365))
self.assertEqual(timestamp.signed.expires, datetime(2031, 1, 2, 0, 0))
# Test whether dateutil.relativedelta works, this provides a much
# easier to use interface for callers
delta = relativedelta(days=1)
timestamp.signed.bump_expiration(delta)
self.assertEqual(timestamp.signed.expires, datetime(2031, 1, 3, 0, 0))
delta = relativedelta(years=5)
timestamp.signed.bump_expiration(delta)
self.assertEqual(timestamp.signed.expires, datetime(2036, 1, 3, 0, 0))
hashes = {'sha256': '0ae9664468150a9aa1e7f11feecb32341658eb84292851367fea2da88e8a58dc'}
fileinfo = copy.deepcopy(timestamp.signed.meta['snapshot.json'])
fileinfo['hashes'] = hashes
fileinfo['version'] = 2
fileinfo['length'] = 520
self.assertNotEqual(timestamp.signed.meta['snapshot.json'], fileinfo)
timestamp.signed.update(2, 520, hashes)
self.assertEqual(timestamp.signed.meta['snapshot.json'], fileinfo)
def add_succinct_roles(self, delegator_name: str, bit_length: int,
name_prefix: str) -> None:
"""Add succinct roles info to a delegator with name "delegator_name".
Note that for each delegated role represented by succinct roles an empty
Targets instance is created.
"""
delegator = self._get_delegator(delegator_name)
if (delegator.delegations is not None
and delegator.delegations.roles is not None):
raise ValueError(
"Can't add a succinct_roles when delegated roles are used")
key, signer = self.create_key()
succinct_roles = SuccinctRoles([], 1, bit_length, name_prefix)
delegator.delegations = Delegations({}, None, succinct_roles)
# Add targets metadata for all bins.
for delegated_name in succinct_roles.get_roles():
self.md_delegates[delegated_name] = Metadata(
Targets(expires=self.safe_expiry))
self.add_signer(delegated_name, signer)
delegator.add_key(key)
def add_delegation(self, delegator_name: str, role: DelegatedRole,
targets: Targets) -> None:
"""Add delegated target role to the repository."""
delegator = self._get_delegator(delegator_name)
if (delegator.delegations is not None
and delegator.delegations.succinct_roles is not None):
raise ValueError("Can't add a role when succinct_roles is used")
# Create delegation
if delegator.delegations is None:
delegator.delegations = Delegations({}, roles={})
assert delegator.delegations.roles is not None
# put delegation last by default
delegator.delegations.roles[role.name] = role
# By default add one new key for the role
key, signer = self.create_key()
delegator.add_key(key, role.name)
self.add_signer(role.name, signer)
# Add metadata for the role
if role.name not in self.md_delegates:
self.md_delegates[role.name] = Metadata(targets, {})
def test_metadata_root(self):
root_path = os.path.join(
self.repo_dir, 'metadata', 'root.json')
root = Metadata.from_file(root_path)
# Add a second key to root role
root_key2 = import_ed25519_publickey_from_file(
os.path.join(self.keystore_dir, 'root_key2.pub'))
keyid = root_key2['keyid']
key_metadata = format_keyval_to_metadata(
root_key2['keytype'], root_key2['scheme'], root_key2['keyval'])
# Assert that root does not contain the new key
self.assertNotIn(keyid, root.signed.roles['root']['keyids'])
self.assertNotIn(keyid, root.signed.keys)
# Add new root key
root.signed.add_key('root', keyid, key_metadata)
# Assert that key is added
self.assertIn(keyid, root.signed.roles['root']['keyids'])
self.assertIn(keyid, root.signed.keys)
# Remove the key
root.signed.remove_key('root', keyid)
# Assert that root does not contain the new key anymore
self.assertNotIn(keyid, root.signed.roles['root']['keyids'])
self.assertNotIn(keyid, root.signed.keys)
def update_delegated_targets(self, data: bytes, role_name: str,
delegator_name: str):
"""Verifies and loads 'data' as new metadata for target 'role_name'.
Args:
data: unverified new metadata as bytes
role_name: The role name of the new metadata
delegator_name: The name of the role delegating to the new metadata
Raises:
RepositoryError: Metadata failed to load or verify. The actual
error type and content will contain more details.
"""
if self.snapshot is None:
raise RuntimeError("Cannot load targets before snapshot")
delegator: Optional[Metadata] = self.get(delegator_name)
if delegator is None:
raise RuntimeError("Cannot load targets before delegator")
logger.debug("Updating %s delegated by %s", role_name, delegator_name)
# Verify against the hashes in snapshot, if any
meta = self.snapshot.signed.meta.get(f"{role_name}.json")
if meta is None:
raise exceptions.RepositoryError(
f"Snapshot does not contain information for '{role_name}'")
try:
meta.verify_length_and_hashes(data)
except exceptions.LengthOrHashMismatchError as e:
raise exceptions.RepositoryError(
f"{role_name} length or hashes do not match") from e
try:
new_delegate = Metadata.from_bytes(data)
except DeserializationError as e:
raise exceptions.RepositoryError("Failed to load snapshot") from e
if new_delegate.signed.type != "targets":
raise exceptions.RepositoryError(
f"Expected 'targets', got '{new_delegate.signed.type}'")
delegator.verify_delegate(role_name, new_delegate)
if new_delegate.signed.version != meta.version:
raise exceptions.BadVersionNumberError(
f"Expected {role_name} version "
f"{meta.version}, got {new_delegate.signed.version}.")
if new_delegate.signed.is_expired(self.reference_time):
raise exceptions.ExpiredMetadataError(
f"New {role_name} is expired")
self._trusted_set[role_name] = new_delegate
logger.debug("Updated %s delegated by %s", role_name, delegator_name)
def deserialize(self, raw_data: bytes) -> Metadata:
"""Deserialize utf-8 encoded JSON bytes into Metadata object."""
try:
json_dict = json.loads(raw_data.decode("utf-8"))
metadata_obj = Metadata.from_dict(json_dict)
except Exception as e: # pylint: disable=broad-except
raise DeserializationError from e
return metadata_obj
def deserialize(self, raw_data: bytes) -> Metadata:
"""Deserialize utf-8 encoded JSON bytes into Metadata object."""
try:
json_dict = json.loads(raw_data.decode("utf-8"))
metadata_obj = Metadata.from_dict(json_dict)
except Exception as e:
raise DeserializationError("Failed to deserialize JSON") from e
return metadata_obj
def test_valid_metadata_serialization(self, test_case_data: bytes) -> None:
md = Metadata.from_bytes(test_case_data)
# Convert to a JSON and sort the keys the way we do in JSONSerializer.
separators = (",", ":")
test_json = json.loads(test_case_data)
test_bytes = json.dumps(test_json,
separators=separators,
sort_keys=True).encode("utf-8")
self.assertEqual(test_bytes, md.to_bytes())
def test_to_from_bytes(self):
for metadata in ["root", "snapshot", "timestamp", "targets"]:
path = os.path.join(self.repo_dir, 'metadata', metadata + '.json')
with open(path, 'rb') as f:
metadata_bytes = f.read()
metadata_obj = Metadata.from_bytes(metadata_bytes)
# Comparate that from_bytes/to_bytes doesn't change the content
# for two cases for the serializer: noncompact and compact.
# Case 1: test noncompact by overriding the default serializer.
self.assertEqual(
metadata_obj.to_bytes(JSONSerializer()), metadata_bytes
)
# Case 2: test compact by using the default serializer.
obj_bytes = metadata_obj.to_bytes()
metadata_obj_2 = Metadata.from_bytes(obj_bytes)
self.assertEqual(
metadata_obj_2.to_bytes(), obj_bytes
)
def test_sign_failures(self) -> None:
# Test throwing UnsignedMetadataError because of signing problems
# related to bad information in the signer.
md = Metadata.from_file(
os.path.join(self.repo_dir, "metadata", "snapshot.json"))
key_dict = copy(self.keystore[Snapshot.type])
key_dict["keytype"] = "rsa"
key_dict["scheme"] = "bad_scheme"
sslib_signer = SSlibSigner(key_dict)
with self.assertRaises(exceptions.UnsignedMetadataError):
md.sign(sslib_signer)
def test_metadata_base(self):
# Use of Snapshot is arbitrary, we're just testing the base class features
# with real data
snapshot_path = os.path.join(
self.repo_dir, 'metadata', 'snapshot.json')
md = Metadata.from_file(snapshot_path)
self.assertEqual(md.signed.version, 1)
md.signed.bump_version()
self.assertEqual(md.signed.version, 2)
self.assertEqual(md.signed.expires, datetime(2030, 1, 1, 0, 0))
md.signed.bump_expiration()
self.assertEqual(md.signed.expires, datetime(2030, 1, 2, 0, 0))
md.signed.bump_expiration(timedelta(days=365))
self.assertEqual(md.signed.expires, datetime(2031, 1, 2, 0, 0))
# Test is_expired with reference_time provided
is_expired = md.signed.is_expired(md.signed.expires)
self.assertTrue(is_expired)
is_expired = md.signed.is_expired(md.signed.expires + timedelta(days=1))
self.assertTrue(is_expired)
is_expired = md.signed.is_expired(md.signed.expires - timedelta(days=1))
self.assertFalse(is_expired)
# Test is_expired without reference_time,
# manipulating md.signed.expires
expires = md.signed.expires
md.signed.expires = datetime.utcnow()
is_expired = md.signed.is_expired()
self.assertTrue(is_expired)
md.signed.expires = datetime.utcnow() + timedelta(days=1)
is_expired = md.signed.is_expired()
self.assertFalse(is_expired)
md.signed.expires = expires
# Test deserializing metadata with non-unique signatures:
data = md.to_dict()
data["signatures"].append({"keyid": data["signatures"][0]["keyid"], "sig": "foo"})
with self.assertRaises(ValueError):
Metadata.from_dict(data)
def test_update_with_invalid_json(self):
repo_dir = os.path.join(os.getcwd(), 'repository_data', 'repository',
'metadata')
data = {}
for md in ["root", "timestamp", "snapshot", "targets", "role1"]:
with open(os.path.join(repo_dir, f"{md}.json"), "rb") as f:
data[md] = f.read()
# root.json not a json file at all
with self.assertRaises(exceptions.RepositoryError):
TrustedMetadataSet(b"")
# root.json is invalid
root = Metadata.from_bytes(data["root"])
root.signed.version += 1
with self.assertRaises(exceptions.RepositoryError):
TrustedMetadataSet(json.dumps(root.to_dict()).encode())
trusted_set = TrustedMetadataSet(data["root"])
trusted_set.root_update_finished()
top_level_md = [
(data["timestamp"], trusted_set.update_timestamp),
(data["snapshot"], trusted_set.update_snapshot),
(data["targets"], trusted_set.update_targets),
]
for metadata, update_func in top_level_md:
# metadata is not json
with self.assertRaises(exceptions.RepositoryError):
update_func(b"")
# metadata is invalid
md = Metadata.from_bytes(metadata)
md.signed.version += 1
with self.assertRaises(exceptions.RepositoryError):
update_func(json.dumps(md.to_dict()).encode())
# metadata is of wrong type
with self.assertRaises(exceptions.RepositoryError):
update_func(data["root"])
update_func(metadata)
def modify_metadata(cls, rolename: str,
modification_func: Callable) -> bytes:
"""Instantiate metadata from rolename type, call modification_func and
sign it again with self.keystore[rolename] signer.
Attributes:
rolename: Denoting the name of the metadata which will be modified.
modification_func: Function that will be called to modify the signed
portion of metadata bytes.
"""
metadata = Metadata.from_bytes(cls.metadata[rolename])
modification_func(metadata.signed)
metadata.sign(cls.keystore[rolename])
return metadata.to_bytes(JSONSerializer(validate=True))
def verify_generation(md: Metadata, path: str) -> None:
"""Verify that newly generated file equals the locally stored one.
Args:
md: Newly generated metadata object.
path: Path to the locally stored metadata file.
"""
with open(path, "rb") as f:
static_md_bytes = f.read()
md_bytes = md.to_bytes(SERIALIZER)
if static_md_bytes != md_bytes:
raise ValueError(
f"Generated data != local data at {path}. Generate a new " +
"metadata with 'python generated_data/generate_md.py'")
def update_timestamp(self, data: bytes):
"""Verifies and loads 'data' as new timestamp metadata.
Args:
data: unverified new timestamp metadata as bytes
Raises:
RepositoryError: Metadata failed to load or verify. The actual
error type and content will contain more details.
"""
if not self._root_update_finished:
raise RuntimeError("Cannot update timestamp before root")
if self.snapshot is not None:
raise RuntimeError("Cannot update timestamp after snapshot")
try:
new_timestamp = Metadata.from_bytes(data)
except DeserializationError as e:
raise exceptions.RepositoryError("Failed to load timestamp") from e
if new_timestamp.signed.type != "timestamp":
raise exceptions.RepositoryError(
f"Expected 'timestamp', got '{new_timestamp.signed.type}'")
self.root.verify_delegate("timestamp", new_timestamp)
# If an existing trusted timestamp is updated,
# check for a rollback attack
if self.timestamp is not None:
# Prevent rolling back timestamp version
if new_timestamp.signed.version < self.timestamp.signed.version:
raise exceptions.ReplayedMetadataError(
"timestamp",
new_timestamp.signed.version,
self.timestamp.signed.version,
)
# Prevent rolling back snapshot version
if (new_timestamp.signed.meta["snapshot.json"].version <
self.timestamp.signed.meta["snapshot.json"].version):
raise exceptions.ReplayedMetadataError(
"snapshot",
new_timestamp.signed.meta["snapshot.json"].version,
self.timestamp.signed.meta["snapshot.json"].version,
)
if new_timestamp.signed.is_expired(self.reference_time):
raise exceptions.ExpiredMetadataError("New timestamp is expired")
self._trusted_set["timestamp"] = new_timestamp
logger.debug("Updated timestamp")
def generate_all_files(dump: Optional[bool] = False,
verify: Optional[bool] = False) -> None:
"""Generate a new repository and optionally verify it.
Args:
dump: Wheter to dump the newly generated files.
verify: Whether to verify the newly generated files with the
local staored.
"""
md_root = Metadata(Root(expires=EXPIRY))
md_timestamp = Metadata(Timestamp(expires=EXPIRY))
md_snapshot = Metadata(Snapshot(expires=EXPIRY))
md_targets = Metadata(Targets(expires=EXPIRY))
md_root.signed.add_key(keys["ed25519_0"], "root")
md_root.signed.add_key(keys["ed25519_1"], "timestamp")
md_root.signed.add_key(keys["ed25519_2"], "snapshot")
md_root.signed.add_key(keys["ed25519_3"], "targets")
for i, md in enumerate([md_root, md_timestamp, md_snapshot, md_targets]):
assert isinstance(md, Metadata)
signer = SSlibSigner({
"keytype": "ed25519",
"scheme": "ed25519",
"keyid": keyids[i],
"keyval": {
"public": public_values[i],
"private": private_values[i],
},
})
md.sign(signer)
path = os.path.join(OUT_DIR, f"{md.signed.type}_with_ed25519.json")
if verify:
verify_generation(md, path)
if dump:
md.to_file(path, SERIALIZER)
def test_sign_verify(self) -> None:
root_path = os.path.join(self.repo_dir, "metadata", "root.json")
root = Metadata[Root].from_file(root_path).signed
# Locate the public keys we need from root
targets_keyid = next(iter(root.roles[Targets.type].keyids))
targets_key = root.keys[targets_keyid]
snapshot_keyid = next(iter(root.roles[Snapshot.type].keyids))
snapshot_key = root.keys[snapshot_keyid]
timestamp_keyid = next(iter(root.roles[Timestamp.type].keyids))
timestamp_key = root.keys[timestamp_keyid]
# Load sample metadata (targets) and assert ...
path = os.path.join(self.repo_dir, "metadata", "targets.json")
md_obj = Metadata.from_file(path)
# ... it has a single existing signature,
self.assertEqual(len(md_obj.signatures), 1)
# ... which is valid for the correct key.
targets_key.verify_signature(md_obj)
with self.assertRaises(exceptions.UnsignedMetadataError):
snapshot_key.verify_signature(md_obj)
# Test verifying with explicitly set serializer
targets_key.verify_signature(md_obj, CanonicalJSONSerializer())
with self.assertRaises(exceptions.UnsignedMetadataError):
targets_key.verify_signature(
md_obj, JSONSerializer()) # type: ignore[arg-type]
sslib_signer = SSlibSigner(self.keystore[Snapshot.type])
# Append a new signature with the unrelated key and assert that ...
sig = md_obj.sign(sslib_signer, append=True)
# ... there are now two signatures, and
self.assertEqual(len(md_obj.signatures), 2)
# ... both are valid for the corresponding keys.
targets_key.verify_signature(md_obj)
snapshot_key.verify_signature(md_obj)
# ... the returned (appended) signature is for snapshot key
self.assertEqual(sig.keyid, snapshot_keyid)
sslib_signer = SSlibSigner(self.keystore[Timestamp.type])
# Create and assign (don't append) a new signature and assert that ...
md_obj.sign(sslib_signer, append=False)
# ... there now is only one signature,
self.assertEqual(len(md_obj.signatures), 1)
# ... valid for that key.
timestamp_key.verify_signature(md_obj)
with self.assertRaises(exceptions.UnsignedMetadataError):
targets_key.verify_signature(md_obj)
def test_metadata_base(self):
# Use of Snapshot is arbitrary, we're just testing the base class features
# with real data
snapshot_path = os.path.join(
self.repo_dir, 'metadata', 'snapshot.json')
md = Metadata.from_file(snapshot_path)
self.assertEqual(md.signed.version, 1)
md.signed.bump_version()
self.assertEqual(md.signed.version, 2)
self.assertEqual(md.signed.expires, datetime(2030, 1, 1, 0, 0))
md.signed.bump_expiration()
self.assertEqual(md.signed.expires, datetime(2030, 1, 2, 0, 0))
md.signed.bump_expiration(timedelta(days=365))
self.assertEqual(md.signed.expires, datetime(2031, 1, 2, 0, 0))