mesh-network-project/relay/connection.py

from crypt_random import secure_random
from lora_handler import LoRaHandler, LoRaMessage

import time
import uasyncio as asyncio


class Connection:
    def __init__(self, bluetooth_handler=None):
        self.bluetooth_handler = bluetooth_handler
        self.load_public_constants()
        
        # generate diffie-hellman keys
        print("Generating keys...")
        print("    - Generating private key...")
        self.private_key = int.from_bytes(secure_random(32), "big") # 32 bytes = 256 bits
        print("    - Generating public key...")
        self.public_key = pow(self.G, self.private_key, self.P)
        
        # start lora handler
        self.lora = LoRaHandler()
        
    async def bluetooth_listener(self):
        while True:
            msg_type, payload = await self.bluetooth_handler.packets.get()
            
            if msg_type == 3: # advertise self
                self.lora.advertise()
        
    async def start(self):
        print("Starting connection...")
        
        if self.bluetooth_handler:
            asyncio.create_task(self.bluetooth_listener())
        
        while True:
            msg: LoRaMessage = await self.lora.message_queue.get()
            
            print(f"Received message from {msg.sender_id}: {msg.payload}")
        
    def load_public_constants(self):
        with open("public_constants.txt", "r") as f:
            self.P = int(f.readline(), 16)
            self.G = int(f.readline(), 16)