C++RegOpenKeyEx越界和缓冲区不足怎么解决

void Remote_Management()
{
    //终端服务器使用了SSL加密
    string result;
    HKEY hEky = NULL;
    LPCTSTR read = _T("SYSTEM\\CurrentControlSet\\Control\\Terminal Server\\WinStations\\RDP-Tcp");
    //打开注册表
    if (ERROR_SUCCESS == RegOpenKeyEx(HKEY_LOCAL_MACHINE, read, 0, KEY_READ, &hEky))
    {
        string buff;
        DWORD dwSize = 0;
        DWORD dwSzType = REG_SZ;
        string *lpchar = NULL;
        //查看共享是否开启
        if (ERROR_SUCCESS == RegQueryValueEx(hEky, _T("WdName"), NULL, &dwSzType, NULL, &dwSize))
        {
            lpchar = new string[dwSize];
            if (ERROR_SUCCESS == RegQueryValueEx(hEky, _T("WdName"), NULL, &dwSzType, (LPBYTE)&lpchar, &dwSize))
            {
                cout << endl;
            }
            else
                cout << endl << "错误1" << endl;
        }
        else 
            cout << endl << "错误2" << endl;
    }

    RegCloseKey(hEky);

    return;
}

将代码加上这个：lpchar = new string[dwSize];就报错越界

//终端服务器使用了SSL加密
    string result;
    HKEY hEky = NULL;
    LPCTSTR read = _T("SYSTEM\\CurrentControlSet\\Control\\Terminal Server\\WinStations\\RDP-Tcp");
    //打开注册表
    if (ERROR_SUCCESS == RegOpenKeyEx(HKEY_LOCAL_MACHINE, read, 0, KEY_READ, &hEky))
    {
        string buff;
        DWORD dwSize = 0;
        DWORD dwSzType = REG_SZ;
        string *lpchar = NULL;
        //查看共享是否开启
        if (ERROR_SUCCESS == RegQueryValueEx(hEky, _T("WdName"), NULL, &dwSzType, (LPBYTE)&buff, &dwSize))
        {
            cout << endl;
        }
        else 
            cout << endl << "错误2" << endl;
    }

    RegCloseKey(hEky);

    return;
}

不加的话就变成缓冲区不足
有什么好的解决办法

https://blog.csdn.net/ruihaha/article/details/51488778