bos3_server

import socket
from Crypto.PublicKey import RSA
from Crypto import Random
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad, unpad
from Crypto.Cipher import PKCS1_OAEP

class Server:
    __sock = None
    __connection = None
    __session_key = None

    def __init__(self, host, port):
        self.__sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.__sock.bind((host, port))

    def handshake(self):
        keys = RSA.generate(1024, Random.new().read)
        rsa_private_key = PKCS1_OAEP.new(RSA.importKey(keys.exportKey("PEM")))
        self.__connection.send(keys.publickey().exportKey(format='PEM', passphrase=None, pkcs=1))
        self.__connection.send(bytes("\n", 'utf-8'))
        resp = self.__connection.recv(1000)
        test = rsa_private_key.decrypt(resp)
        self.__session_key = AES.new(test, AES.MODE_ECB)

    def send_msg(self, data):
        data = self.__session_key.encrypt(pad(bytes(data, 'utf-8'), 16))
        self.__connection.send(data)

    def run(self):
        self.__sock.listen(1)
        print("Waiting for client")
        self.__connection, addr = self.__sock.accept()
        print(f"connected to {addr[0]}:{addr[1]}")
        self.handshake()
        while True:
            msg = input("Server: ")
            self.send_msg(msg)
            resp = self.__connection.recv(1000)
            data = unpad(self.__session_key.decrypt(resp), 16)
            print(f"Client: {data}")


server = Server("127.0.0.1", 9001)
server.run()