import socket,os,hmac,pickle,threading,datetime

class Server:
    
    def __init__(self,secret_key):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.addr = ('127.0.0.1', 8088)
        self.users = {}
        self.secret_key = secret_key

    def start_server(self):
        try:
            self.sock.bind(self.addr)
        except Exception as e:
            print(e)
        self.sock.listen(5)
        print("服务器已开启，ip地址为{}等待连接...".format(self.addr))
        self.accept_cont()

    def __auth(self,sock,addr,secret_key):
        print('来自{}的客户端发起连接，开始验证客户端合法性...'.format(addr))
        msg = os.urandom(32)
        sock.sendall(msg)
        h = hmac.new(secret_key, msg, digestmod='md5')
        digest = h.digest()
        response = sock.recv(len(digest))
        return hmac.compare_digest(digest, response)        
        
    def accept_cont(self):
        while True:
            sock,addr = self.sock.accept()
            if not self.__auth(sock,addr,self.secret_key):
                print('来自{}的客户端验证失败，关闭连接!'.format(addr))
                sock.close()
            else:
                print('来自{}的客户端验证通过!'.format(addr))
                self.users[addr] = sock 
                number = len(self.users)
                print("用户{}连接成功！现在共有{}位用户".format(addr, number))

                threading.Thread(target=self.recv_send, args=(sock, addr)).start()
            
    def recv_send(self,sock,addr):
        while True:
            try:
                response = pickle.loads(sock.recv(4096))
                msg = "{}用户{}发来消息：{}".format(self.get_time(), addr, response)

                for client in self.users.values():
                    client.send(pickle.dumps(msg))
            except ConnectionResetError:
                print("用户{}已经退出！".format(addr))
                self.users[addr].close()
                self.users.pop(addr)
                msg = "{}用户{}已经退出！".format(self.get_time(), addr)
                for client in self.users.values():
                    client.send(pickle.dumps(msg))
                break

    def close_server(self):
        for client in self.users.values():
            client.close()
        self.sock.close()
        os._exit(0)
    
    def get_time(self):
        now = datetime.datetime.now()
        send_time = now.strftime("%Y-%m-%d %H:%M:%S")
        return send_time

    def run(self):
        threading.Thread(target=self.start_server).start()
        while True:
            cmd = input("input 'exit' to stop sever! >>>")
            if cmd == "exit":
                self.close_server()
            else:
                print("输入命令无效，请重新输入！")

secret_key = b'I have a red phone!'
server = Server(secret_key)
server.run()

客户端：

import socket,hmac,pickle,threading,os

class Client:
    """"""
    def __init__(self,ip_port,secret_key):
        self.ip_port = ip_port
        self.secret_key = secret_key
        self.client = self.conn_server()
        self.active = True
    
    def conn_server(self):
        client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
        client.setsockopt(socket.SOL_SOCKET,socket.SO_KEEPALIVE,True)
        err = client.connect_ex(self.ip_port)
        if err != 0:
            print("please check sever's ip_port!")
            return None
        msg = client.recv(32)
        h = hmac.new(self.secret_key, msg, digestmod='md5')
        digest = h.digest()
        client.sendall(digest)

        return client
    
    def send_msg(self):
        def send_msg2(client):
            msg = input('input you words:>>>').strip()
            if msg in ['quit','exit']:
                print('you just closed the connection.')
                client.close()
                self.active = False
            else:
                client.sendall(pickle.dumps(msg))
        while self.active:
            send_msg2(self.client)

    def recv_msg(self):
        while True:
            try:
                data = self.client.recv(1024)
            except Exception as err:
                print('you just lost the connection.err:',err)
                self.client.close()
                break
            print('recv msg：',pickle.loads(data))
        os._exit(0)

    def run(self):
        threading.Thread(target=self.recv_msg).start()
        self.send_msg()

ip_port = ('127.0.0.1',8088)
secret_key = b'I have a red phone!'
client0 = Client(ip_port,secret_key)
client0.run()