Start a windows service and launch cmd

Question

Do I need to enable Interactive desktp for it to work and what is the correct code to start an EXE or cmd window? I\'m still unable to start the service even when I had enab

Answer 1

When running as a service you won't be able to launch anything that needs to interact with the desktop OR will spawn it's own windows.

As Aliostad said, you need to call Win API calls to CreateProcessAsUser and emulate the user in order with this to work. This involves emulating the logged in user and using their credentials to "lift" your process into process isolation level 1 (which gives you access to the windowing system and things like the GPU).

I am doing this in an app I wrote and it does work but I agree with Aliostad there is a bit of Black magic going on and it generally sucks

Having said all that, you can spawn worker processes from within a service as along as they don't require things that are in process isolation level 1 (Windowing, GPU etc..)

cmd.exe by default will try to create a window, this is why your example is failing. You could set the following ProcessStartInfo properties to get it work.

CreateNoWindow WindowStyle

Answer 2

I wrote an application watchdog service which simply restarts an application (in my case a Console Window App).

1. I found a very good Hands-On Lab Tutorial (in C++) which I tried at it worked for Session 0 Isolation at: http://msdn.microsoft.com/en-us/Windows7TrainingCourse_Win7Session0Isolation

2. I converted that C++ Sample into C#. After a few tests it worked. As long as I stay logged on and don't log out and log on again that code works perfect. I have to do a little to catch the Session Logout/Login. But for simple log-in and Work Condition in Windows the watchdog works as expected.

3. Here is that required PInvoke code:

   [StructLayout(LayoutKind.Sequential)]
   public struct STARTUPINFO
   {
       public int cb;
       public String lpReserved;
       public String lpDesktop;
       public String lpTitle;
       public uint dwX;
       public uint dwY;
       public uint dwXSize;
       public uint dwYSize;
       public uint dwXCountChars;
       public uint dwYCountChars;
       public uint dwFillAttribute;
       public uint dwFlags;
       public short wShowWindow;
       public short cbReserved2;
       public IntPtr lpReserved2;
       public IntPtr hStdInput;
       public IntPtr hStdOutput;
       public IntPtr hStdError;
   }
   
   [StructLayout(LayoutKind.Sequential)]
   public struct PROCESS_INFORMATION
   {
       public IntPtr hProcess;
       public IntPtr hThread;
       public uint dwProcessId;
       public uint dwThreadId;
   }
   
   
   public enum TOKEN_TYPE
   {
       TokenPrimary = 1,
       TokenImpersonation
   }
   
   public enum SECURITY_IMPERSONATION_LEVEL
   {
       SecurityAnonymous,
       SecurityIdentification,
       SecurityImpersonation,
       SecurityDelegation
   }
   
   [StructLayout(LayoutKind.Sequential)]
   public struct SECURITY_ATTRIBUTES
   {
       public int nLength;
       public IntPtr lpSecurityDescriptor;
       public int bInheritHandle;
   }
   
   
   [DllImport("kernel32.dll", EntryPoint = "CloseHandle", SetLastError = true, CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
   public extern static bool CloseHandle(IntPtr handle);
   
   [DllImport("kernel32.dll")]
   public static extern uint WTSGetActiveConsoleSessionId();
   
   [DllImport("wtsapi32.dll", SetLastError = true)]
   public static extern bool WTSQueryUserToken(UInt32 sessionId, out IntPtr Token);
   
   [DllImport("advapi32.dll", EntryPoint = "CreateProcessAsUser", SetLastError = true, CharSet = CharSet.Ansi, CallingConvention = CallingConvention.StdCall)]
   public extern static bool CreateProcessAsUser(IntPtr hToken, String lpApplicationName, String lpCommandLine, ref SECURITY_ATTRIBUTES lpProcessAttributes,
       ref SECURITY_ATTRIBUTES lpThreadAttributes, bool bInheritHandle, int dwCreationFlags, IntPtr lpEnvironment,
       String lpCurrentDirectory, ref STARTUPINFO lpStartupInfo, out PROCESS_INFORMATION lpProcessInformation);
   
   
   [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
   public extern static bool DuplicateTokenEx(
       IntPtr hExistingToken,
       uint dwDesiredAccess,
       ref SECURITY_ATTRIBUTES lpTokenAttributes,
       SECURITY_IMPERSONATION_LEVEL ImpersonationLevel,
       TOKEN_TYPE TokenType,
       out IntPtr phNewToken);
   

4. Here is the encapsuled method :

       private void CreateUserProcess()
   {
   
       bool ret;
       SECURITY_ATTRIBUTES sa = new SECURITY_ATTRIBUTES();
   
       uint dwSessionID = WTSGetActiveConsoleSessionId();
   
   
       this.EventLog.WriteEntry("WTSGetActiveConsoleSessionId: " + dwSessionID, EventLogEntryType.FailureAudit);
   
   
       IntPtr Token = new IntPtr();
       ret = WTSQueryUserToken((UInt32)dwSessionID, out Token);
   
       if (ret == false)
       {
           this.EventLog.WriteEntry("WTSQueryUserToken failed with " + Marshal.GetLastWin32Error(), EventLogEntryType.FailureAudit);
   
       }
   
       const uint MAXIMUM_ALLOWED  = 0x02000000;
       IntPtr DupedToken = IntPtr.Zero;
   
       ret = DuplicateTokenEx(Token,
           MAXIMUM_ALLOWED,
           ref sa,
           SECURITY_IMPERSONATION_LEVEL.SecurityIdentification,
           TOKEN_TYPE.TokenPrimary,
           out DupedToken);
   
       if (ret == false)
       {
           this.EventLog.WriteEntry("DuplicateTokenEx failed with " + Marshal.GetLastWin32Error(), EventLogEntryType.FailureAudit);
   
       }
       else
       {
           this.EventLog.WriteEntry("DuplicateTokenEx SUCCESS", EventLogEntryType.SuccessAudit); 
       }
   
       STARTUPINFO si = new STARTUPINFO();
       si.cb = Marshal.SizeOf(si);
       //si.lpDesktop = "";
   
       string commandLinePath;
   
       // commandLinePath example: "c:\myapp.exe c:\myconfig.xml" . cmdLineArgs can be ommited
       commandLinePath = AppPath + " " + CmdLineArgs;
   
       PROCESS_INFORMATION pi = new PROCESS_INFORMATION();
       //CreateProcessAsUser(hDuplicatedToken, NULL, lpszClientPath, NULL, NULL, FALSE,
       //                    0,
       //                    NULL, NULL, &si, &pi)
       ret = CreateProcessAsUser(DupedToken, null, commandLinePath, ref sa, ref sa, false, 0, (IntPtr)0, null, ref si, out pi);
   
       if (ret == false)
       {
           this.EventLog.WriteEntry("CreateProcessAsUser failed with " + Marshal.GetLastWin32Error(), EventLogEntryType.FailureAudit);
   
   
       }
       else
       {
           this.EventLog.WriteEntry("CreateProcessAsUser SUCCESS.  The child PID is" + pi.dwProcessId, EventLogEntryType.SuccessAudit);
           CloseHandle(pi.hProcess);
           CloseHandle(pi.hThread);
       }
   
       ret = CloseHandle(DupedToken);
       if (ret == false)
       {
           this.EventLog.WriteEntry("CloseHandle LastError: " + Marshal.GetLastWin32Error(), EventLogEntryType.Error);
       }
       else
       {
       this.EventLog.WriteEntry("CloseHandle SUCCESS", EventLogEntryType.Information);
   
       }
   }
   

I hope it is useful !

Answer 3

I have gone through all the pain of doing this.

Under windows 7/Vista/2008 it is not possible to load any interactive process from a service - without calling a number of Win API. = BLACK MAGIC

Have a look here and here.

The code below does the trick, use it with your own risk:

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("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 bool CreateProcessAsCurrentUser(string processExe)
    {

        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)
        {
            result = CreateProcessAsUser(duplicate, processExe, null,
                IntPtr.Zero, IntPtr.Zero, false, (UInt32)CreateProcessFlags.CREATE_NEW_CONSOLE, 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));
        }



        return result;
    }

    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));
        return wtsSessionInfos.Where(x => x.State == ConnectionState.Active).Count() > 0;
    }

    private static IntPtr GetCurrentUserToken()
    {
        List<WTS_SESSION_INFO> wtsSessionInfos = ListSessions();
        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;
    }

}

Answer 4

The function below will launch an executable as active user from a windows service.

//Function to run a process as active user from windows service
void ImpersonateActiveUserAndRun(WCHAR* path, WCHAR* args)
{
    DWORD session_id = -1;
    DWORD session_count = 0;

    WTS_SESSION_INFOA *pSession = NULL;


    if (WTSEnumerateSessions(WTS_CURRENT_SERVER_HANDLE, 0, 1, &pSession, &session_count))
    {
        //log success
    }
    else
    {
        //log error
        return;
    }

    for (int i = 0; i < session_count; i++)
    {
        session_id = pSession[i].SessionId;

        WTS_CONNECTSTATE_CLASS wts_connect_state = WTSDisconnected;
        WTS_CONNECTSTATE_CLASS* ptr_wts_connect_state = NULL;

        DWORD bytes_returned = 0;
        if (::WTSQuerySessionInformation(
            WTS_CURRENT_SERVER_HANDLE,
            session_id,
            WTSConnectState,
            reinterpret_cast<LPTSTR*>(&ptr_wts_connect_state),
            &bytes_returned))
        {
            wts_connect_state = *ptr_wts_connect_state;
            ::WTSFreeMemory(ptr_wts_connect_state);
            if (wts_connect_state != WTSActive) continue;
        }
        else
        {
            //log error
            continue;
        }

        HANDLE hImpersonationToken;

        if (!WTSQueryUserToken(session_id, &hImpersonationToken))
        {
            //log error
            continue;
        }


        //Get real token from impersonation token
        DWORD neededSize1 = 0;
        HANDLE *realToken = new HANDLE;
        if (GetTokenInformation(hImpersonationToken, (::TOKEN_INFORMATION_CLASS) TokenLinkedToken, realToken, sizeof(HANDLE), &neededSize1))
        {
            CloseHandle(hImpersonationToken);
            hImpersonationToken = *realToken;
        }
        else
        {
            //log error
            continue;
        }


        HANDLE hUserToken;

        if (!DuplicateTokenEx(hImpersonationToken,
            //0,
            //MAXIMUM_ALLOWED,
            TOKEN_ASSIGN_PRIMARY | TOKEN_ALL_ACCESS | MAXIMUM_ALLOWED,
            NULL,
            SecurityImpersonation,
            TokenPrimary,
            &hUserToken))
        {
            //log error
            continue;
        }

        // Get user name of this process
        //LPTSTR pUserName = NULL;
        WCHAR* pUserName;
        DWORD user_name_len = 0;

        if (WTSQuerySessionInformationW(WTS_CURRENT_SERVER_HANDLE, session_id, WTSUserName, &pUserName, &user_name_len))
        {
            //log username contained in pUserName WCHAR string
        }

        //Free memory                         
        if (pUserName) WTSFreeMemory(pUserName);

        ImpersonateLoggedOnUser(hUserToken);

        STARTUPINFOW StartupInfo;
        GetStartupInfoW(&StartupInfo);
        StartupInfo.cb = sizeof(STARTUPINFOW);
        //StartupInfo.lpDesktop = "winsta0\\default";

        PROCESS_INFORMATION processInfo;

        SECURITY_ATTRIBUTES Security1;
        Security1.nLength = sizeof SECURITY_ATTRIBUTES;

        SECURITY_ATTRIBUTES Security2;
        Security2.nLength = sizeof SECURITY_ATTRIBUTES;

        void* lpEnvironment = NULL;

        // Get all necessary environment variables of logged in user
        // to pass them to the new process
        BOOL resultEnv = CreateEnvironmentBlock(&lpEnvironment, hUserToken, FALSE);
        if (!resultEnv)
        {
            //log error
            continue;
        }

        WCHAR PP[1024]; //path and parameters
        ZeroMemory(PP, 1024 * sizeof WCHAR);
        wcscpy(PP, path);
        wcscat(PP, L" ");
        wcscat(PP, args);

        // Start the process on behalf of the current user 
        BOOL result = CreateProcessAsUserW(hUserToken, 
            NULL,
            PP,
            //&Security1,
            //&Security2,
            NULL,
            NULL,
            FALSE, 
            NORMAL_PRIORITY_CLASS | CREATE_NEW_CONSOLE,
            //lpEnvironment,
            NULL,
            //"C:\\ProgramData\\some_dir",
            NULL,
            &StartupInfo,
            &processInfo);

        if (!result)
        {
            //log error
        }
        else
        {
            //log success
        }

        DestroyEnvironmentBlock(lpEnvironment);

        CloseHandle(hImpersonationToken);
        CloseHandle(hUserToken);
        CloseHandle(realToken);

        RevertToSelf();
    }

    WTSFreeMemory(pSession);
}