Impersonate user in Windows Service

Question

I am trying to impersonate a domain user in a windows service with the service logged in as the Local System Account.

So far, I am only able to get this to work by l

Answer 1

I was able to get it to work.

For normal impersonating, I used the following code

public class Impersonation : IDisposable
{
    private WindowsImpersonationContext _impersonatedUserContext;

    #region FUNCTIONS (P/INVOKE)

    // Declare signatures for Win32 LogonUser and CloseHandle APIs
    [DllImport("advapi32.dll", SetLastError = true)]
    static extern bool LogonUser(
      string principal,
      string authority,
      string password,
      LogonSessionType logonType,
      LogonProvider logonProvider,
      out IntPtr token);

    [DllImport("kernel32.dll", SetLastError = true)]
    static extern bool CloseHandle(IntPtr handle);

    [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    static extern int DuplicateToken(IntPtr hToken,
        int impersonationLevel,
        ref IntPtr hNewToken);

    [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    static extern bool RevertToSelf();

    #endregion

    #region ENUMS

    enum LogonSessionType : uint
    {
        Interactive = 2,
        Network,
        Batch,
        Service,
        NetworkCleartext = 8,
        NewCredentials
    }

    enum LogonProvider : uint
    {
        Default = 0, // default for platform (use this!)
        WinNT35,     // sends smoke signals to authority
        WinNT40,     // uses NTLM
        WinNT50      // negotiates Kerb or NTLM
    }

    #endregion


    /// 

    /// Class to allow running a segment of code under a given user login context
    /// 
    /// domain\user
    /// user's domain password
    public Impersonation(string domain, string username, string password)
    {
        var token = ValidateParametersAndGetFirstLoginToken(username, domain, password);

        var duplicateToken = IntPtr.Zero;
        try
        {
            if (DuplicateToken(token, 2, ref duplicateToken) == 0)
            {


                throw new InvalidOperationException("DuplicateToken call to reset permissions for this token failed");
            }

            var identityForLoggedOnUser = new WindowsIdentity(duplicateToken);
            _impersonatedUserContext = identityForLoggedOnUser.Impersonate();
            if (_impersonatedUserContext == null)
            {
                throw new InvalidOperationException("WindowsIdentity.Impersonate() failed");
            }
        }
        finally
        {
            if (token != IntPtr.Zero)
                CloseHandle(token);
            if (duplicateToken != IntPtr.Zero)
                CloseHandle(duplicateToken);
        }
    }

    private static IntPtr ValidateParametersAndGetFirstLoginToken(string domain, string username, string password)
    {


        if (!RevertToSelf())
        {
            ErrorLogger.LogEvent("RevertToSelf call to remove any prior impersonations failed", System.Diagnostics.EventLogEntryType.Error, "");

            throw new InvalidOperationException("RevertToSelf call to remove any prior impersonations failed");

        }

        IntPtr token;

        var result = LogonUser(domain, username,
                               password,
                               LogonSessionType.NewCredentials,
                               LogonProvider.Default,
                               out token);
        if (!result)
        {
            var errorCode = Marshal.GetLastWin32Error();
            ErrorLogger.LogEvent(string.Format("Could not impersonate the elevated user.  LogonUser: {2}\\{1} returned error code: {0}.", errorCode, username, domain), System.Diagnostics.EventLogEntryType.Error, "");
            throw new InvalidOperationException("Logon for user " + username + " failed.");
        }
        return token;
    }

    public void Dispose()
    {
        // Stop impersonation and revert to the process identity
        if (_impersonatedUserContext != null)
        {
            _impersonatedUserContext.Undo();
            _impersonatedUserContext = null;
        }
    }
}

To run it I do the following:

            FileInfo fi = new FileInfo(logfile);
            using (var imp = new Impersonation(Settings.ImpersonateUser.AccountDomain, Settings.ImpersonateUser.AccountName, Settings.ImpersonateUser.AccountPassword))
            {
                if (File.Exists(filename))
                    File.Delete(filename);
                fi.MoveTo(filename);
            }

For running console commands, I used the following code.

public class CreateProcess
{

    #region Constants

    const UInt32 INFINITE = 0xFFFFFFFF;
    const UInt32 WAIT_FAILED = 0xFFFFFFFF;

    #endregion


    #region ENUMS

    [Flags]
    public enum LogonType
    {
        LOGON32_LOGON_INTERACTIVE = 2,
        LOGON32_LOGON_NETWORK = 3,
        LOGON32_LOGON_BATCH = 4,
        LOGON32_LOGON_SERVICE = 5,
        LOGON32_LOGON_UNLOCK = 7,
        LOGON32_LOGON_NETWORK_CLEARTEXT = 8,
        LOGON32_LOGON_NEW_CREDENTIALS = 9
    }


    [Flags]
    public enum LogonProvider
    {
        LOGON32_PROVIDER_DEFAULT = 0,
        LOGON32_PROVIDER_WINNT35,
        LOGON32_PROVIDER_WINNT40,
        LOGON32_PROVIDER_WINNT50
    }

    #endregion


    #region Structs

    [StructLayout(LayoutKind.Sequential)]
    public 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)]
    public struct PROCESS_INFORMATION
    {
        public IntPtr hProcess;
        public IntPtr hThread;
        public Int32 dwProcessId;
        public Int32 dwThreadId;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct SECURITY_ATTRIBUTES
    {
        public int nLength;
        public unsafe byte* lpSecurityDescriptor;
        public int bInheritHandle;
    }

    public enum TOKEN_TYPE
    {
        TokenPrimary = 1,
        TokenImpersonation
    }

    public enum SECURITY_IMPERSONATION_LEVEL
    {
        SecurityAnonymous,
        SecurityIdentification,
        SecurityImpersonation,
        SecurityDelegation
    }

    #endregion


    #region FUNCTIONS (P/INVOKE)

    [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    static extern bool RevertToSelf();

    [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    static extern int DuplicateToken(IntPtr hToken,
        int impersonationLevel,
        ref IntPtr hNewToken);


    [DllImport("advapi32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    public static extern Boolean LogonUser
    (
        String UserName,
        String Domain,
        String Password,
        LogonType dwLogonType,
        LogonProvider dwLogonProvider,
        out IntPtr phToken
    );


    [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    public static extern Boolean CreateProcessAsUser
    (
        IntPtr hToken,
        String lpApplicationName,
        String lpCommandLine,
        IntPtr lpProcessAttributes,
        IntPtr lpThreadAttributes,
        Boolean bInheritHandles,
        Int32 dwCreationFlags,
        IntPtr lpEnvironment,
        String lpCurrentDirectory,
        ref STARTUPINFO lpStartupInfo,
        out PROCESS_INFORMATION lpProcessInformation
    );





    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern UInt32 WaitForSingleObject
    (
        IntPtr hHandle,
        UInt32 dwMilliseconds
    );

    [DllImport("kernel32", SetLastError = true)]
    public static extern Boolean CloseHandle(IntPtr handle);

    #endregion

    #region Functions

    public static int LaunchCommand(string command, string domain, string account, string password)
    {
        int ProcessId = -1;
        PROCESS_INFORMATION processInfo = new PROCESS_INFORMATION();
        STARTUPINFO startInfo = new STARTUPINFO();
        Boolean bResult = false;

        UInt32 uiResultWait = WAIT_FAILED;

        var token = ValidateParametersAndGetFirstLoginToken(domain, account, password);

        var duplicateToken = IntPtr.Zero;
        try
        {

            startInfo.cb = Marshal.SizeOf(startInfo);
            //  startInfo.lpDesktop = "winsta0\\default";

            bResult = CreateProcessAsUser(
                token,
                null,
                command,
                IntPtr.Zero,
                IntPtr.Zero,
                false,
                0,
                IntPtr.Zero,
                null,
                ref startInfo,
                out processInfo
            );

            if (!bResult) { throw new Exception("CreateProcessAsUser error #" + Marshal.GetLastWin32Error()); }

            // Wait for process to end
            uiResultWait = WaitForSingleObject(processInfo.hProcess, INFINITE);

            ProcessId = processInfo.dwProcessId;

            if (uiResultWait == WAIT_FAILED) { throw new Exception("WaitForSingleObject error #" + Marshal.GetLastWin32Error()); }

        }
        finally
        {
            if (token != IntPtr.Zero)
                CloseHandle(token);
            if (duplicateToken != IntPtr.Zero)
                CloseHandle(duplicateToken);
            CloseHandle(processInfo.hProcess);
            CloseHandle(processInfo.hThread);
        }

        return ProcessId;
    }


    private static IntPtr ValidateParametersAndGetFirstLoginToken(string domain, string username, string password)
    {


        if (!RevertToSelf())
        {
            ErrorLogger.LogEvent("RevertToSelf call to remove any prior impersonations failed", System.Diagnostics.EventLogEntryType.Error, "");
            throw new Exception("RevertToSelf call to remove any prior impersonations failed");
        }

        IntPtr token;

        var result = LogonUser(username,
                               domain,
                               password,
                               LogonType.LOGON32_LOGON_INTERACTIVE,
                               LogonProvider.LOGON32_PROVIDER_DEFAULT,
                               out token);
        if (!result)
        {
            var errorCode = Marshal.GetLastWin32Error();
            ErrorLogger.LogEvent(string.Format("Could not impersonate the elevated user.  LogonUser: {2}\\{1} returned error code: {0}.", errorCode, username, domain), System.Diagnostics.EventLogEntryType.Error, "");
            throw new Exception("Logon for user " + username + " failed.");
        }
        return token;
    }

    #endregion

}

and executing it doing the following

string commandLine = "Robocopy " + args;

ProcessId = CreateProcess.LaunchCommand(commandLine, ImperDomain, ImperUsername, ImperPassword);

I also had to make some changes to the local policy since I want able to copy permissions in robocopy.

Thanks for all the comments and help.