nomos-specs/mixnet/config.py
Youngjoon Lee 9f58a72d4d
mixnet v2
2024-06-26 16:48:39 +09:00

58 lines
1.5 KiB
Python

from __future__ import annotations
import random
from dataclasses import dataclass
from typing import List
from cryptography.hazmat.primitives.asymmetric.x25519 import (
X25519PrivateKey,
X25519PublicKey,
)
from pysphinx.sphinx import Node as SphinxNode
@dataclass
class MixnetConfig:
node_configs: List[NodeConfig]
membership: MixMembership
@dataclass
class NodeConfig:
private_key: X25519PrivateKey
transmission_rate_per_sec: int # Global Transmission Rate
@dataclass
class MixMembership:
nodes: List[NodeInfo]
def generate_route(self, num_hops: int, last_mix: NodeInfo) -> list[NodeInfo]:
"""
Generate a mix route for a Sphinx packet.
The pre-selected mix_destination is used as a last mix node in the route,
so that associated packets can be merged together into a original message.
"""
route = [self.choose() for _ in range(num_hops - 1)]
route.append(last_mix)
return route
def choose(self) -> NodeInfo:
"""
Choose a mix node as a mix destination that will reconstruct a message from Sphinx packets.
"""
return random.choice(self.nodes)
@dataclass
class NodeInfo:
private_key: X25519PrivateKey
def public_key(self) -> X25519PublicKey:
return self.private_key.public_key()
def sphinx_node(self) -> SphinxNode:
# TODO: Use a pre-signed incentive tx, instead of NodeAddress
dummy_node_addr = bytes(32)
return SphinxNode(self.private_key, dummy_node_addr)