c++ - 在 Qt 服务器上验证用户

Question

我正在尝试使用 C++/QtTcpSocket 为个人项目(多人国际象棋游戏)实现身份验证系统。

我的 friend 提出了一种验证用户的方法，但我想问问是否有更简单或更好的方法。来自 Python 背景，主要从事此项目以加深对 C++ 的理解。

我会把我 friend 建议的方法发上来，寻求更好的解决方案。

他以一种伪代码的方式构建了它。服务器基本搭建完成，现在希望实现Authentication

*干杯

void process_packet(PACKET *pkt)
{
    switch(pkt->PacketID)
    {
        case 0: // let's say packet id 0 is the logon packet; packet contents are username and password
        {
            //let's say packet size is 101 bytes; packet id was already received, so get the other 100 bytes
            unsigned char BUFFER[101] = {0}; // i always add an extra byte to the end of the buffer to allow for off-by-one errors ^_^

            int result = recv_packet(pkt->cSocket, 100, BUFFER);

            if(result <= 0)
                return; // connection error; no packet data was received

            unsigned char *UserName = BUFFER+0; //+0 is not neccessary, but the username starts at the beginning. just getting the point across.
            unsigned char *PassWord = BUFFER+50;

            //side note: if we did "unsigned long *blah = BUFFER+4" or something, we would have to make sure the byte order is right. network byte order is BIG ENDIAN
            //  WINDOWS byte order is LITTLE ENDIAN

            result = QueryDatabase("SELECT username, password FROM chess_players WHERE username = '%s'", FILTER_INVALID_CHARS(UserName));

            // check result

            unsigned char ServerResponse[2] = {0};

            if(result['password'] == PassWord)
            {
                ServerResponse[0] = 1; // packet id will be 1. the next byte can be 1 or 0 to indicate logon success or failure.
                ServerResponse[1] = true; // so packet 0x0101 mean logon success, packet 0x0100 means logon failure
                send_packet(pkt->cSocket, ServerResponse, 2);
            } else {

                ServerResponse[0] = 1;
                ServerResponse[1] = false;
                send_packet(pkt->cSocket, ServerResponse, 2);
            }
        }
        break;

        default:
        {
            // received an unknown packet id; send a packet to the client that indicates an error_status_t

            unsigned char *ServerResponse[2] = {0};
            ServerResponse[0] = 2; // packet id 2 means server error
            ServerResponse[1] = 0; // error code 0 means 'unknown packet id'

            send_packet(pkt_cSocket, ServerResponse, 2);
        }
        break;
    }

    delete pkt; // must delete pkt, was created with 'new' in get_client_packets()
}

Answer 1

这看起来很 C 风格，不像 Qt 做事的方式。您的问题没有通用的答案，但我的建议如下:

听newConnection() QTcpServer 的信号.您的处理程序必须调用 nextPendingConnection()让下一个客户在队列中等待。您要做的第一件事可能是您的用户身份验证。一旦通过身份验证，您就可以将 QTcpSocket 保留在您的事件连接列表中。

看看例如财富客户端/服务器示例如何实际写入/读取数据包。您可能还想查看流运算符 <<序列化你的对象。与您发布的低级方法相比，这更容易且更不容易出错。此外，QDataStream 将自动处理主机和网络字节顺序。