studio - Ejecute el programa capturando capturas de pantalla del servicio de Windows

windows service c#

Question

Estoy escribiendo un servicio de Windows, que gestionará algunas capturas de pantalla del programa del agente. El programa de agente funciona bien, sin ningún problema, solo toma una captura de pantalla y lo guarda en un archivo bmp. Pero cuando intento ejecutar este programa de agente desde mi servicio, no funciona, todo lo que obtengo son imágenes en negro (como si tratara de capturar una captura de pantalla directamente desde mi servicio) Mi código dentro del servicio es:

ServiceStatus.dwCurrentState = SERVICE_RUNNING;
SetServiceStatus (hStatus, &ServiceStatus);

SHELLEXECUTEINFO seInfo;
seInfo.cbSize = sizeof(SHELLEXECUTEINFO);
seInfo.fMask = SEE_MASK_NOCLOSEPROCESS;
seInfo.hwnd = NULL;
seInfo.lpVerb = TEXT("open");
seInfo.lpFile = TEXT("D://dev//work//agent.exe");
seInfo.lpDirectory = TEXT("D://dev//work//");
seInfo.nShow = SW_SHOWNORMAL;
seInfo.hInstApp = NULL;

ShellExecuteEx(&seInfo);

Traté de cambiar las propiedades del servicio, para permitirle interactuar con el escritorio, cambiar el usuario del servicio de SYSTEM a mi cuenta local, nada ayuda. ¿Qué puedo hacer para que funcione correctamente?

UPD Bueno, supongo que esto sucede porque mi servicio ejecuta el programa en la sesión 0. También probé CreateProcess() y CreateProcessAsUser() , sin resultado. Entonces, ¿cómo puedo crear proceda NO en sesión0?

Answer 1

Aliostad hizo todo el trabajo pesado para esto. Eche un vistazo a su código, es un excelente comienzo. Tenga en cuenta que necesitará una aplicación separada para tomar la captura de pantalla, ya que se debe iniciar un nuevo proceso mientras se hace pasar por el usuario conectado. https://stackoverflow.com/a/4147868/125406

Aquí está mi versión (totalmente basada en el código de Aliostad). Agrega parámetros de línea de comando, una espera para que finalice el proceso y la devolución del código de salida.

public static class ProcessAsCurrentUser
{

    /// <summary>
    /// Connection state of a session.
    /// </summary>
    public enum ConnectionState
    {
        /// <summary>
        /// A user is logged on to the session.
        /// </summary>
        Active,

        /// <summary>
        /// A client is connected to the session.
        /// </summary>
        Connected,

        /// <summary>
        /// The session is in the process of connecting to a client.
        /// </summary>
        ConnectQuery,

        /// <summary>
        /// This session is shadowing another session.
        /// </summary>
        Shadowing,

        /// <summary>
        /// The session is active, but the client has disconnected from it.
        /// </summary>
        Disconnected,

        /// <summary>
        /// The session is waiting for a client to connect.
        /// </summary>
        Idle,

        /// <summary>
        /// The session is listening for connections.
        /// </summary>
        Listening,

        /// <summary>
        /// The session is being reset.
        /// </summary>
        Reset,

        /// <summary>
        /// The session is down due to an error.
        /// </summary>
        Down,

        /// <summary>
        /// The session is initializing.
        /// </summary>
        Initializing
    }


    [StructLayout(LayoutKind.Sequential)]
    class SECURITY_ATTRIBUTES
    {
        public int nLength;
        public IntPtr lpSecurityDescriptor;
        public int bInheritHandle;
    }


    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    struct STARTUPINFO
    {
        public Int32 cb;
        public string lpReserved;
        public string lpDesktop;
        public string lpTitle;
        public Int32 dwX;
        public Int32 dwY;
        public Int32 dwXSize;
        public Int32 dwYSize;
        public Int32 dwXCountChars;
        public Int32 dwYCountChars;
        public Int32 dwFillAttribute;
        public Int32 dwFlags;
        public Int16 wShowWindow;
        public Int16 cbReserved2;
        public IntPtr lpReserved2;
        public IntPtr hStdInput;
        public IntPtr hStdOutput;
        public IntPtr hStdError;
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct PROCESS_INFORMATION
    {
        public IntPtr hProcess;
        public IntPtr hThread;
        public int dwProcessId;
        public int dwThreadId;
    }

    enum LOGON_TYPE
    {
        LOGON32_LOGON_INTERACTIVE = 2,
        LOGON32_LOGON_NETWORK,
        LOGON32_LOGON_BATCH,
        LOGON32_LOGON_SERVICE,
        LOGON32_LOGON_UNLOCK = 7,
        LOGON32_LOGON_NETWORK_CLEARTEXT,
        LOGON32_LOGON_NEW_CREDENTIALS
    }

    enum LOGON_PROVIDER
    {
        LOGON32_PROVIDER_DEFAULT,
        LOGON32_PROVIDER_WINNT35,
        LOGON32_PROVIDER_WINNT40,
        LOGON32_PROVIDER_WINNT50
    }

    [Flags]
    enum CreateProcessFlags : uint
    {
        CREATE_BREAKAWAY_FROM_JOB = 0x01000000,
        CREATE_DEFAULT_ERROR_MODE = 0x04000000,
        CREATE_NEW_CONSOLE = 0x00000010,
        CREATE_NEW_PROCESS_GROUP = 0x00000200,
        CREATE_NO_WINDOW = 0x08000000,
        CREATE_PROTECTED_PROCESS = 0x00040000,
        CREATE_PRESERVE_CODE_AUTHZ_LEVEL = 0x02000000,
        CREATE_SEPARATE_WOW_VDM = 0x00000800,
        CREATE_SHARED_WOW_VDM = 0x00001000,
        CREATE_SUSPENDED = 0x00000004,
        CREATE_UNICODE_ENVIRONMENT = 0x00000400,
        DEBUG_ONLY_THIS_PROCESS = 0x00000002,
        DEBUG_PROCESS = 0x00000001,
        DETACHED_PROCESS = 0x00000008,
        EXTENDED_STARTUPINFO_PRESENT = 0x00080000,
        INHERIT_PARENT_AFFINITY = 0x00010000
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct WTS_SESSION_INFO
    {
        public int SessionID;
        [MarshalAs(UnmanagedType.LPTStr)] public string WinStationName;
        public ConnectionState State;
    }

    [DllImport("wtsapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    public static extern Int32 WTSEnumerateSessions(IntPtr hServer, int reserved, int version,
        ref IntPtr sessionInfo, ref int count);


    [DllImport("advapi32.dll", EntryPoint = "CreateProcessAsUserW", SetLastError = true, CharSet = CharSet.Auto)]
    static extern bool CreateProcessAsUser(
        IntPtr hToken,
        string lpApplicationName,
        string lpCommandLine,
        IntPtr lpProcessAttributes,
        IntPtr lpThreadAttributes,
        bool bInheritHandles,
        UInt32 dwCreationFlags,
        IntPtr lpEnvironment,
        string lpCurrentDirectory,
        ref STARTUPINFO lpStartupInfo,
        out PROCESS_INFORMATION lpProcessInformation);

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern Int32 WaitForSingleObject(IntPtr handle, Int32 wait);

    public const Int32 INFINITE = -1;
    public const Int32 WAIT_ABANDONED = 0x80;
    public const Int32 WAIT_OBJECT_0 = 0x00;
    public const Int32 WAIT_TIMEOUT = 0x102;
    public const Int32 WAIT_FAILED = -1;

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern bool GetExitCodeProcess(IntPtr hProcess, out uint exitCode);

    [DllImport("wtsapi32.dll")]
    public static extern void WTSFreeMemory(IntPtr memory);

    [DllImport("kernel32.dll")]
    private static extern UInt32 WTSGetActiveConsoleSessionId();

    [DllImport("wtsapi32.dll", SetLastError = true)]
    static extern int WTSQueryUserToken(UInt32 sessionId, out IntPtr Token);

    [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    public extern static bool DuplicateTokenEx(
        IntPtr hExistingToken,
        uint dwDesiredAccess,
        IntPtr lpTokenAttributes,
        int ImpersonationLevel,
        int TokenType,
        out IntPtr phNewToken);

    private const int TokenImpersonation = 2;
    private const int SecurityIdentification = 1;
    private const int MAXIMUM_ALLOWED = 0x2000000;
    private const int TOKEN_DUPLICATE = 0x2;
    private const int TOKEN_QUERY = 0x00000008;

    /// <summary>
    /// Launches a process for the current logged on user if there are any.
    /// If none, return false as well as in case of 
    /// 
    /// ##### !!! BEWARE !!! ####  ------------------------------------------
    /// This code will only work when running in a windows service (where it is really needed)
    /// so in case you need to test it, it needs to run in the service. Reason
    /// is a security privileg which only services have (SE_??? something, cant remember)!
    /// </summary>
    /// <param name="processExe"></param>
    /// <returns></returns>
    public static uint CreateProcessAsCurrentUser(string processExe, string commandLine)
    {

        IntPtr duplicate = new IntPtr();
        STARTUPINFO info = new STARTUPINFO();
        PROCESS_INFORMATION procInfo = new PROCESS_INFORMATION();

        Debug.WriteLine(string.Format("CreateProcessAsCurrentUser. processExe: " + processExe));

        IntPtr p = GetCurrentUserToken();

        bool result = DuplicateTokenEx(p, MAXIMUM_ALLOWED | TOKEN_QUERY | TOKEN_DUPLICATE, IntPtr.Zero,
            SecurityIdentification, SecurityIdentification, out duplicate);
        Debug.WriteLine(string.Format("DuplicateTokenEx result: {0}", result));
        Debug.WriteLine(string.Format("duplicate: {0}", duplicate));


        if (result)
        {
            //NOTE: CREATE_NO_WINDOW will hide the console 
            //If there are commandline options, pass them AND the exe in 
            //commandLine and leave processExe empty.
            result = CreateProcessAsUser(duplicate, processExe, commandLine,
                //                    IntPtr.Zero, IntPtr.Zero, false, (UInt32) CreateProcessFlags.CREATE_NEW_CONSOLE, IntPtr.Zero, null,
                IntPtr.Zero, IntPtr.Zero, false, (UInt32)CreateProcessFlags.CREATE_NO_WINDOW, IntPtr.Zero, null,
                ref info, out procInfo);
            Debug.WriteLine(string.Format("CreateProcessAsUser result: {0}", result));

        }


        if (p.ToInt32() != 0)
        {
            Marshal.Release(p);
            Debug.WriteLine(string.Format("Released handle p: {0}", p));
        }


        if (duplicate.ToInt32() != 0)
        {
            Marshal.Release(duplicate);
            Debug.WriteLine(string.Format("Released handle duplicate: {0}", duplicate));
        }

        //Wait for the process to complete
        WaitForSingleObject(procInfo.hProcess, (int)INFINITE);

        //Get and return the exit code
        uint exitcode;
        GetExitCodeProcess(procInfo.hProcess, out exitcode);

        return exitcode;
    }

    public static int GetCurrentSessionId()
    {
        uint sessionId = WTSGetActiveConsoleSessionId();
        Debug.WriteLine(string.Format("sessionId: {0}", sessionId));

        if (sessionId == 0xFFFFFFFF)
            return -1;
        else
            return (int)sessionId;
    }

    public static bool IsUserLoggedOn()
    {
        List<WTS_SESSION_INFO> wtsSessionInfos = ListSessions();
        Debug.WriteLine(string.Format("Number of sessions: {0}", wtsSessionInfos.Count));
        int activeSessionCount = 0;
        foreach (var session in wtsSessionInfos)
        {
            if (session.State == ConnectionState.Active)
                activeSessionCount++;
        }
        //return wtsSessionInfos.Where(x => x.State == ConnectionState.Active).Count() > 0;
        return activeSessionCount > 0;
    }

    private static IntPtr GetCurrentUserToken()
    {
        List<WTS_SESSION_INFO> wtsSessionInfos = ListSessions();
        int sessionId = 0;
        foreach (var session in wtsSessionInfos)
        {
            if (session.State == ConnectionState.Active)
            {
                sessionId = session.SessionID;
                break;
            }
        }
        //Old Linq method
        //int sessionId = wtsSessionInfos.Where(x => x.State == ConnectionState.Active).FirstOrDefault().SessionID;
        //int sessionId = GetCurrentSessionId();

        Debug.WriteLine(string.Format("sessionId: {0}", sessionId));
        if (sessionId == int.MaxValue)
        {
            return IntPtr.Zero;
        }
        else
        {
            IntPtr p = new IntPtr();
            int result = WTSQueryUserToken((UInt32)sessionId, out p);
            Debug.WriteLine(string.Format("WTSQueryUserToken result: {0}", result));
            Debug.WriteLine(string.Format("WTSQueryUserToken p: {0}", p));

            return p;
        }
    }

    public static List<WTS_SESSION_INFO> ListSessions()
    {
        IntPtr server = IntPtr.Zero;
        List<WTS_SESSION_INFO> ret = new List<WTS_SESSION_INFO>();

        try
        {
            IntPtr ppSessionInfo = IntPtr.Zero;

            Int32 count = 0;
            Int32 retval = WTSEnumerateSessions(IntPtr.Zero, 0, 1, ref ppSessionInfo, ref count);
            Int32 dataSize = Marshal.SizeOf(typeof(WTS_SESSION_INFO));

            Int64 current = (int)ppSessionInfo;

            if (retval != 0)
            {
                for (int i = 0; i < count; i++)
                {
                    WTS_SESSION_INFO si =
                        (WTS_SESSION_INFO)Marshal.PtrToStructure((System.IntPtr)current,
                            typeof(WTS_SESSION_INFO));
                    current += dataSize;

                    ret.Add(si);
                }

                WTSFreeMemory(ppSessionInfo);
            }
        }
        catch (Exception exception)
        {
            Debug.WriteLine(exception.ToString());
        }

        return ret;
    }

}

Pasamos un nombre de archivo como parámetro a la aplicación de captura de pantalla y luego esperamos a que se complete. El servicio luego recoge el archivo y lo procesa y lo elimina.

También encontramos otra forma de evitar esto usando tuberías con nombre. Estoy menos familiarizado con esa solución.