nucypher/tests/learning/test_fault_tolerance.py

190 lines
7.7 KiB
Python

from collections import namedtuple
from functools import partial
import pytest
from eth_keys.datatypes import Signature as EthSignature
from twisted.logger import globalLogPublisher, LogLevel
from constant_sorrow.constants import NOT_SIGNED
from nucypher.characters.lawful import Ursula
from nucypher.characters.unlawful import Vladimir
from nucypher.crypto.powers import SigningPower, CryptoPower
from nucypher.network.nodes import FleetStateTracker
from nucypher.utilities.sandbox.constants import INSECURE_DEVELOPMENT_PASSWORD
from nucypher.utilities.sandbox.middleware import MockRestMiddleware
from nucypher.utilities.sandbox.ursula import make_federated_ursulas
def test_blockchain_ursula_substantiates_stamp(blockchain_ursulas):
first_ursula = list(blockchain_ursulas)[0]
signature_as_bytes = first_ursula._evidence_of_decentralized_identity
signature = EthSignature(signature_bytes=signature_as_bytes)
proper_public_key_for_first_ursula = signature.recover_public_key_from_msg(bytes(first_ursula.stamp))
proper_address_for_first_ursula = proper_public_key_for_first_ursula.to_checksum_address()
assert proper_address_for_first_ursula == first_ursula.checksum_public_address
# This method is a shortcut for the above.
assert first_ursula._stamp_has_valid_wallet_signature
def test_blockchain_ursula_verifies_stamp(blockchain_ursulas):
first_ursula = list(blockchain_ursulas)[0]
# This Ursula does not yet have a verified stamp
first_ursula.verified_stamp = False
first_ursula.stamp_is_valid()
# ...but now it's verified.
assert first_ursula.verified_stamp
def test_blockchain_ursula_is_not_valid_with_unsigned_identity_evidence(blockchain_ursulas, caplog):
lonely_blockchain_learner, blockchain_teacher, unsigned = list(blockchain_ursulas)[0:3]
unsigned._evidence_of_decentralized_identity = NOT_SIGNED
# Wipe known nodes.
lonely_blockchain_learner._Learner__known_nodes = FleetStateTracker()
lonely_blockchain_learner._current_teacher_node = blockchain_teacher
lonely_blockchain_learner.remember_node(blockchain_teacher)
warnings = []
def warning_trapper(event):
if event['log_level'] == LogLevel.warn:
warnings.append(event)
globalLogPublisher.addObserver(warning_trapper)
lonely_blockchain_learner.learn_from_teacher_node()
globalLogPublisher.removeObserver(warning_trapper)
# We received one warning during learning, and it was about this very matter.
assert len(warnings) == 1
assert warnings[0]['log_format'] == unsigned.invalid_metadata_message.format(unsigned)
# minus 2 for self and, of course, unsigned.
assert len(lonely_blockchain_learner.known_nodes) == len(blockchain_ursulas) - 2
assert blockchain_teacher in lonely_blockchain_learner.known_nodes
assert unsigned not in lonely_blockchain_learner.known_nodes
def test_vladimir_cannot_verify_interface_with_ursulas_signing_key(blockchain_ursulas):
his_target = list(blockchain_ursulas)[4]
# Vladimir has his own ether address; he hopes to publish it along with Ursula's details
# so that Alice (or whomever) pays him instead of Ursula, even though Ursula is providing the service.
# He finds a target and verifies that its interface is valid.
assert his_target.interface_is_valid()
# Now Vladimir imitates Ursula - copying her public keys and interface info, but inserting his ether address.
vladimir = Vladimir.from_target_ursula(his_target, claim_signing_key=True)
# Vladimir can substantiate the stamp using his own ether address...
vladimir.substantiate_stamp(password=INSECURE_DEVELOPMENT_PASSWORD)
vladimir.stamp_is_valid()
# Now, even though his public signing key matches Ursulas...
assert vladimir.stamp == his_target.stamp
# ...he is unable to pretend that his interface is valid
# because the interface validity check contains the canonical public address as part of its message.
with pytest.raises(vladimir.InvalidNode):
vladimir.interface_is_valid()
# Consequently, the metadata as a whole is also invalid.
with pytest.raises(vladimir.InvalidNode):
vladimir.validate_metadata()
def test_vladimir_uses_his_own_signing_key(blockchain_alice, blockchain_ursulas):
"""
Similar to the attack above, but this time Vladimir makes his own interface signature
using his own signing key, which he claims is Ursula's.
"""
his_target = list(blockchain_ursulas)[4]
fraduluent_keys = CryptoPower(power_ups=Ursula._default_crypto_powerups)
vladimir = Vladimir.from_target_ursula(target_ursula=his_target)
message = vladimir._signable_interface_info_message()
signature = vladimir._crypto_power.power_ups(SigningPower).sign(vladimir.timestamp_bytes() + message)
vladimir._interface_signature_object = signature
vladimir.substantiate_stamp(password=INSECURE_DEVELOPMENT_PASSWORD)
# With this slightly more sophisticated attack, his metadata does appear valid.
vladimir.validate_metadata()
# However, the actual handshake proves him wrong.
with pytest.raises(vladimir.InvalidNode):
vladimir.verify_node(blockchain_alice.network_middleware, certificate_filepath="doesn't matter")
def test_emit_warning_upon_new_version(ursula_federated_test_config, caplog):
lonely_ursula_maker = partial(make_federated_ursulas,
ursula_config=ursula_federated_test_config,
quantity=2,
know_each_other=True)
learner = lonely_ursula_maker().pop()
teacher, new_node = lonely_ursula_maker()
new_node.TEACHER_VERSION = learner.LEARNER_VERSION + 1
learner._current_teacher_node = teacher
warnings = []
def warning_trapper(event):
if event['log_level'] == LogLevel.warn:
warnings.append(event)
globalLogPublisher.addObserver(warning_trapper)
learner.learn_from_teacher_node()
assert len(warnings) == 1
warnings[0]['log_format'] == learner.unknown_version_message.format(new_node, new_node.TEACHER_VERSION,
learner.LEARNER_VERSION)
# Now let's go a little further: make the version totally unrecognizable.
crazy_bytes_representation = int(learner.LEARNER_VERSION + 1).to_bytes(2,
byteorder="big") + b"totally unintelligible nonsense"
Response = namedtuple("MockResponse", ("content", "status_code"))
response = Response(content=crazy_bytes_representation, status_code=200)
learner.network_middleware.get_nodes_via_rest = lambda *args, **kwargs: response
learner.learn_from_teacher_node()
assert len(warnings) == 2
warnings[1]['log_format'] == learner.unknown_version_message.format(new_node, new_node.TEACHER_VERSION,
learner.LEARNER_VERSION)
globalLogPublisher.removeObserver(warning_trapper)
def test_node_posts_future_version(federated_ursulas):
ursula = list(federated_ursulas)[0]
middleware = MockRestMiddleware()
warnings = []
def warning_trapper(event):
if event['log_level'] == LogLevel.warn:
warnings.append(event)
globalLogPublisher.addObserver(warning_trapper)
crazy_node = b"invalid-node"
middleware.get_nodes_via_rest(node=ursula,
announce_nodes=(crazy_node,))
assert len(warnings) == 1
future_node = list(federated_ursulas)[1]
future_node.TEACHER_VERSION = future_node.TEACHER_VERSION + 10
future_node_bytes = bytes(future_node)
middleware.get_nodes_via_rest(node=ursula,
announce_nodes=(future_node_bytes,))
assert len(warnings) == 2