/// <summary>
        /// 处理协议请求
        /// </summary>
        private bool DoProtocolRequest()
        {
            //取前4字节
            byte[]    buffer;
            IPAddress ipAddress = null;
            byte      rep       = 0x07; //不支持的命令

            if (SocketUtils.Receive(this.Client, 4, out buffer))
            {
                if (buffer.Length == 4)
                {
                    //判断地址类型
                    switch (buffer[3])
                    {
                    case 0x01:
                        //IPV4
                        if (SocketUtils.Receive(this.Client, 4, out buffer))
                        {
                            ipAddress = new IPAddress(buffer);
                        }
                        break;

                    case 0x03:
                        //域名
                        if (SocketUtils.Receive(this.Client, 1, out buffer))
                        {
                            //取得域名的长度
                            if (SocketUtils.Receive(this.Client, (uint)(buffer[0]), out buffer))
                            {
                                //取得域名地址
                                string      address   = Encoding.ASCII.GetString(buffer);
                                IPAddress[] addresses = Dns.GetHostAddresses(address);
                                if (addresses.Length != 0)
                                {
                                    ipAddress = addresses[0];
                                }
                                else
                                {
                                    rep = 0x04;      //主机不可达
                                }
                            }
                        }
                        break;

                    case 0x04:
                        //IPV6;
                        if (SocketUtils.Receive(this.Client, 16, out buffer))
                        {
                            ipAddress = new IPAddress(buffer);
                        }
                        break;

                    default:
                        rep = 0x08;     //不支持的地址类型
                        break;
                    }
                }
            }

            if (ipAddress != null && rep == 0x07)
            {
                //取得端口号
                if (SocketUtils.Receive(this.Client, 2, out buffer))
                {
                    Array.Reverse(buffer);  //反转端口值
                    this.RemoteEndPoint = new IPEndPoint(ipAddress, BitConverter.ToUInt16(buffer, 0));
                    rep = 0x00;
                    this.Server.WriteLineLog(string.Format("于{0}接收到客户端要求对主机{1}进行连接的请求....", DateTime.Now, this.RemoteEndPoint));
                }
            }

            //输出应答
            MemoryStream stream = new MemoryStream();

            stream.WriteByte(0x05);
            stream.WriteByte(rep);
            stream.WriteByte(0x00);
            stream.WriteByte(0x01);
            IPEndPoint localEP = (IPEndPoint)Client.LocalEndPoint;

            byte[] localIP = localEP.Address.GetAddressBytes();
            stream.Write(localIP, 0, localIP.Length);
            byte[] localPort = BitConverter.GetBytes((ushort)IPAddress.HostToNetworkOrder(localEP.Port));
            stream.Write(localPort, 0, localPort.Length);
            SocketUtils.Send(this.Client, stream.ToArray());

            return(this.RemoteEndPoint != null);
        }
        /// <summary>
        /// 处理身份验证
        /// </summary>
        private bool ValidateIdentity()
        {
            byte[] buffer;
            byte   ep = 0xFF;
            string username = string.Empty, password = string.Empty;

            //报文格式:0x01 | 用户名长度(1字节)| 用户名(长度根据用户名长度域指定) | 口令长度(1字节) | 口令(长度由口令长度域指定)
            if (SocketUtils.Receive(this.Client, 2, out buffer))
            {
                if (buffer.Length == 2)
                {
                    //用户名为空
                    if (buffer[1] == 0x00)
                    {
                        if (string.IsNullOrEmpty(this.Server.UserName))
                        {
                            ep = 0x00;  //用户名为空
                        }
                    }
                    else
                    {
                        if (SocketUtils.Receive(this.Client, (uint)buffer[1], out buffer))
                        {
                            username = Encoding.ASCII.GetString(buffer);
                            if (!string.IsNullOrEmpty(this.Server.UserName))
                            {
                                ep = (byte)(username.Equals(this.Server.UserName) ? 0x00 : 0xFF);
                            }
                        }
                    }
                    if (ep == 0x00)
                    {
                        ep = 0xFF;
                        //判断密码
                        if (SocketUtils.Receive(this.Client, 1, out buffer))
                        {
                            if (buffer[0] == 0x00)
                            {
                                if (!string.IsNullOrEmpty(this.Server.Password))
                                {
                                    ep = 0x00;  //密码为空
                                }
                            }
                            else
                            {
                                if (SocketUtils.Receive(this.Client, (uint)buffer[0], out buffer))
                                {
                                    password = Encoding.ASCII.GetString(buffer);
                                    if (!string.IsNullOrEmpty(this.Server.Password))
                                    {
                                        ep = (byte)(password.Equals(this.Server.Password) ? 0x00 : 0xFF);
                                    }
                                }
                            }
                        }
                    }
                }
            }

            //输出应答
            SocketUtils.Send(this.Client, new byte[] { 0x01, ep });
            this.Server.WriteLineLog(string.Format("于{0}接收到客户端{1}的身份验证请求[UserName={3},Password={4}],结果:{2}...",
                                                   DateTime.Now, this.Client.RemoteEndPoint, (ep == 0x00 ? "通过" : "失败"), username, password));
            return(ep == 0x00);
        }