def revoke_arrangement(id_as_hex):
"""
REST endpoint for revoking/deleting a KFrag from a node.
"""
from nucypher.policy.collections import Revocation
revocation = Revocation.from_bytes(request.data)
log.info("Received revocation: {} -- for arrangement {}".format(
bytes(revocation).hex(), id_as_hex))
# Check that the request is the same for the provided revocation
if not id_as_hex == revocation.arrangement_id.hex():
log.debug("Couldn't identify an arrangement with id {}".format(
id_as_hex))
return Response(status_code=400)
try:
with datastore.describe(PolicyArrangement,
id_as_hex,
writeable=True) as policy_arrangement:
if revocation.verify_signature(
policy_arrangement.alice_verifying_key):
policy_arrangement.delete()
except (DatastoreTransactionError, InvalidSignature) as e:
log.debug("Exception attempting to revoke: {}".format(e))
return Response(
response='KFrag not found or revocation signature is invalid.',
status=404)
else:
log.info("KFrag successfully removed.")
return Response(response='KFrag deleted!', status=200)
def reencrypt_via_rest(id_as_hex):
# Get Policy Arrangement
try:
arrangement_id = binascii.unhexlify(id_as_hex)
except (binascii.Error, TypeError):
return Response(response=b'Invalid arrangement ID', status=405)
try:
# Get KFrag
# TODO: Yeah, well, what if this arrangement hasn't been enacted? 1702
with datastore.describe(PolicyArrangement,
id_as_hex) as policy_arrangement:
kfrag = policy_arrangement.kfrag
alice_verifying_key = policy_arrangement.alice_verifying_key
except RecordNotFound:
return Response(response=arrangement_id, status=404)
# Get Work Order
from nucypher.policy.collections import WorkOrder # Avoid circular import
alice_address = canonical_address_from_umbral_key(alice_verifying_key)
work_order_payload = request.data
work_order = WorkOrder.from_rest_payload(
arrangement_id=arrangement_id,
rest_payload=work_order_payload,
ursula=this_node,
alice_address=alice_address)
log.info(
f"Work Order from {work_order.bob}, signed {work_order.receipt_signature}"
)
# Re-encrypt
response = this_node._reencrypt(
kfrag=kfrag,
work_order=work_order,
alice_verifying_key=alice_verifying_key)
# Now, Ursula saves this workorder to her database...
# Note: we give the work order a random ID to store it under.
with datastore.describe(Workorder, str(uuid.uuid4()),
writeable=True) as new_workorder:
new_workorder.arrangement_id = work_order.arrangement_id
new_workorder.bob_verifying_key = work_order.bob.stamp.as_umbral_pubkey(
)
new_workorder.bob_signature = work_order.receipt_signature
headers = {'Content-Type': 'application/octet-stream'}
return Response(headers=headers, response=response)
def set_policy(id_as_hex):
"""
REST endpoint for setting a kFrag.
"""
policy_message_kit = UmbralMessageKit.from_bytes(request.data)
alices_verifying_key = policy_message_kit.sender_verifying_key
alice = _alice_class.from_public_keys(
verifying_key=alices_verifying_key)
try:
cleartext = this_node.verify_from(alice,
policy_message_kit,
decrypt=True)
except InvalidSignature:
# TODO: Perhaps we log this? Essentially 355.
return Response(status_code=400)
if not this_node.federated_only:
# This splitter probably belongs somewhere canonical.
transaction_splitter = BytestringSplitter(32)
tx, kfrag_bytes = transaction_splitter(cleartext,
return_remainder=True)
try:
# Get all of the arrangements and verify that we'll be paid.
# TODO: We'd love for this part to be impossible to reduce the risk of collusion. #1274
arranged_addresses = this_node.policy_agent.fetch_arrangement_addresses_from_policy_txid(
tx, timeout=this_node.synchronous_query_timeout)
except TimeExhausted:
# Alice didn't pay. Return response with that weird status code.
this_node.suspicious_activities_witnessed['freeriders'].append(
(alice, f"No transaction matching {tx}."))
return Response(status=402)
this_node_has_been_arranged = this_node.checksum_address in arranged_addresses
if not this_node_has_been_arranged:
this_node.suspicious_activities_witnessed['freeriders'].append(
(alice,
f"The transaction {tx} does not list me as a Worker - it lists {arranged_addresses}."
))
return Response(status=402)
else:
_tx = NO_BLOCKCHAIN_CONNECTION
kfrag_bytes = cleartext
kfrag = KFrag.from_bytes(kfrag_bytes)
if not kfrag.verify(signing_pubkey=alices_verifying_key):
raise InvalidSignature("{} is invalid".format(kfrag))
with datastore.describe(PolicyArrangement, id_as_hex,
writeable=True) as policy_arrangement:
if not policy_arrangement.alice_verifying_key == alice.stamp.as_umbral_pubkey(
):
raise alice.SuspiciousActivity
policy_arrangement.kfrag = kfrag
# TODO: Sign the arrangement here. #495
return "" # TODO: Return A 200, with whatever policy metadata.
def consider_arrangement():
from nucypher.policy.policies import Arrangement
arrangement = Arrangement.from_bytes(request.data)
# TODO: Look at the expiration and figure out if we're even staking that long. 1701
with datastore.describe(PolicyArrangement,
arrangement.id.hex(),
writeable=True) as new_policy_arrangement:
new_policy_arrangement.arrangement_id = arrangement.id.hex(
).encode()
new_policy_arrangement.expiration = arrangement.expiration
new_policy_arrangement.alice_verifying_key = arrangement.alice.stamp.as_umbral_pubkey(
)
# TODO: Fine, we'll add the arrangement here, but if we never hear from Alice again to enact it,
# we need to prune it at some point. #1700
headers = {'Content-Type': 'application/octet-stream'}
# TODO: Make this a legit response #234.
return Response(
b"This will eventually be an actual acceptance of the arrangement.",
headers=headers)