nucypher/nkms/network/protocols.py

90 lines
3.7 KiB
Python

from kademlia.node import Node
from kademlia.protocol import KademliaProtocol
from kademlia.utils import digest
from nkms.crypto.api import keccak_digest
from nkms.crypto.constants import HASH_DIGEST_LENGTH
from nkms.crypto.signature import Signature
from nkms.crypto.utils import BytestringSplitter
from nkms.keystore.keypairs import PublicKey
from nkms.network.constants import NODE_HAS_NO_STORAGE
from nkms.network.node import NuCypherNode
from nkms.network.routing import NuCypherRoutingTable
dht_value_splitter = BytestringSplitter(Signature, PublicKey, (bytes, HASH_DIGEST_LENGTH))
class NuCypherHashProtocol(KademliaProtocol):
def __init__(self, sourceNode, storage, ksize, *args, **kwargs):
super().__init__(sourceNode, storage, ksize, *args, **kwargs)
self.router = NuCypherRoutingTable(self, ksize, sourceNode)
self.illegal_keys_seen = []
def check_node_for_storage(self, node):
try:
return node.can_store()
except AttributeError:
return True
def rpc_ping(self, sender, nodeid, node_capabilities=[]):
source = NuCypherNode(nodeid, sender[0], sender[1], capabilities_as_strings=node_capabilities)
self.welcomeIfNewNode(source)
return self.sourceNode.id
async def callStore(self, nodeToAsk, key, value):
# nodeToAsk = NuCypherNode
if self.check_node_for_storage(nodeToAsk):
address = (nodeToAsk.ip, nodeToAsk.port)
# TODO: encrypt `value` with public key of nodeToAsk
store_future = self.store(address, self.sourceNode.id, key, value)
result = await store_future
success, data = self.handleCallResponse(result, nodeToAsk)
return success, data
else:
return NODE_HAS_NO_STORAGE, False
def determine_legality_of_dht_key(self, signature, sender_pubkey_sig, message, hrac, dht_key, dht_value):
proper_key = digest(keccak_digest(bytes(sender_pubkey_sig) + bytes(hrac)))
verified = signature.verify(hrac, sender_pubkey_sig)
if not verified or not proper_key == dht_key:
self.log.warning("Got request to store illegal k/v: {} / {}".format(dht_key, dht_value))
self.illegal_keys_seen.append(dht_key)
return False
else:
return True
def rpc_store(self, sender, nodeid, key, value):
source = NuCypherNode(nodeid, sender[0], sender[1])
self.welcomeIfNewNode(source)
self.log.debug("got a store request from %s" % str(sender))
if value.startswith(b"uaddr") or value.startswith(b"trmap"):
signature, sender_pubkey_sig, hrac, message = dht_value_splitter(value[5::], return_remainder=True)
# extra_info is a hash of the policy_group.id in the case of a treasure map, or a TTL in the case
# of an Ursula interface. TODO: Decide whether to keep this notion and, if so, use the TTL.
do_store = self.determine_legality_of_dht_key(signature, sender_pubkey_sig, message, hrac, key, value)
else:
self.log.info("Got request to store bad k/v: {} / {}".format(key, value))
do_store = False
if do_store:
self.log.info("Storing k/v: {} / {}".format(key, value))
self.storage[key] = value
return do_store
class NuCypherSeedOnlyProtocol(NuCypherHashProtocol):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def rpc_store(self, sender, nodeid, key, value):
source = Node(nodeid, sender[0], sender[1])
self.welcomeIfNewNode(source)
self.log.debug(
"got a store request from %s, but THIS VALUE WILL NOT BE STORED as this is a seed-only node." % str(
sender))
return True