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Following this link, I have implemented WTSQueryUserToken in my C# solution and called the CreateProcessAsUserWrapper.LaunchChildProcess("app_path") method from the OnStart of my Windows Service which is made to run as "LocalSystem". It is able to start the process which can interact with desktop, but for Windows Professional and not for Windows Ultimate. I tried it on Windows Professional 64 bit and it is able to successfully start the process on user log on interactively, but on Windows Ultimate 64 bit version the CreateProcessAsUser method is returning false and the service can be seen running at SCM whereas the process is not.
My process is a win form app which needs to run with currently logged on user account for desktop interaction and uses the InteropServices. Can it be a framework issue? How to get to the problem? Please help.
Edit:
Both the machines are running Windows 7 64-bit. I added the following code to get the error code after CreateProcessAsUser and it returns "The requested operation requires elevation" as error.
string errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
It is happening only in Windows 7 Ultimate and not in Windows 7 Professional. I need to run my process for every logged on user and that is why I think I can't use the CreateProcessWithLogonW method instead. How can I fix this elevation privilege issue now?
Edit:
There was 2 app.manifest files, one inside the service project and the other inside the win form (process) project. I removed both the files, built the msi with WiX and tested again. Now it is successfully running on every machine, the process being started with every logged on user account. But, one problem is caused now. Actually I need to write some log under the windows/system folder, which I can't do now. I am getting "UnauthorizedAccessException" thrown from the process. Moreover, no user except administrator is allowed to stop or uninstall the process, but in this case a user can start the Task Manager and end the process from there since it is running with the corresponding user account. Is it possible to run the process with the user account but with elevated privilege, so that I can write my log under windows/system folder and prevent the user from stopping the process without admin permission? At least resolving the first issue i.e writing log files under system folder is very important for me.
Edit:
After adding SetTokenInformation along with DuplicateTokenEx my service fails to start the app with the log "SetTokenInformation() returns FALSE. ERROR: A required privilege is not held by the client". I am providing the full code, please see if I have updated it correctly with all the steps.
using System;
using System.IO;
using System.ComponentModel;
using System.Security.Principal;
using System.Text;
using System.Collections;
using System.Web;
using System.Net;
using System.Diagnostics;
using System.Runtime.InteropServices; // DllImport
namespace CSCreateProcessAsUserFromService
{
class CreateProcessAsUserWrapper1
{
static String tmp_log = Path.Combine(CreateDirectoryAtSystemFolder(), "Temp-Report-Service.txt");
static string errorMessage;
public static void LaunchChildProcess(string ChildProcName)
{
IntPtr ppSessionInfo = IntPtr.Zero;
UInt32 SessionCount = 0;
File.AppendAllText(tmp_log, "\n" + "LaunchChildProcess() OK 1" + "\n");
if (WTSEnumerateSessions(
(IntPtr)WTS_CURRENT_SERVER_HANDLE, // Current RD Session Host Server handle would be zero.
0, // This reserved parameter must be zero.
1, // The version of the enumeration request must be 1.
ref ppSessionInfo, // This would point to an array of session info.
ref SessionCount // This would indicate the length of the above array.
))
{
File.AppendAllText(tmp_log, "\n" + "WTSEnumerateSessions OK 2" + "\n");
for (int nCount = 0; nCount < SessionCount; nCount++)
{
// Extract each session info and check if it is the
// "Active Session" of the current logged-on user.
//ppSessionInfo = new IntPtr(ppSessionInfo.ToInt32() + nCount * Marshal.SizeOf(typeof(WTS_SESSION_INFO)));
WTS_SESSION_INFO tSessionInfo = (WTS_SESSION_INFO)Marshal.PtrToStructure(
ppSessionInfo + nCount * Marshal.SizeOf(typeof(WTS_SESSION_INFO)),
typeof(WTS_SESSION_INFO)
);
/*WTS_SESSION_INFO tSessionInfo = (WTS_SESSION_INFO)Marshal.PtrToStructure(
new IntPtr(ppSessionInfo.ToInt32() + nCount * Marshal.SizeOf(typeof(WTS_SESSION_INFO))),
typeof(WTS_SESSION_INFO)
);*/
if (WTS_CONNECTSTATE_CLASS.WTSActive == tSessionInfo.State)
{
WindowsIdentity m_ImpersonatedUser;
IntPtr hToken = IntPtr.Zero;
IntPtr hTokenDuplicate = IntPtr.Zero;
const int SecurityImpersonation = 2;
const int TokenType = 1;
File.AppendAllText(tmp_log, "\n" + "if (WTS_CONNECTSTATE_CLASS.WTSActive == tSessionInfo.State) 3" + "\n");
if (RevertToSelf())
{
File.AppendAllText(tmp_log, "\n" + "RevertToSelf() TRUE 4 " + "\n");
if (WTSQueryUserToken(tSessionInfo.SessionID, out hToken))
{
File.AppendAllText(tmp_log, "\n" + "if (WTSQueryUserToken(tSessionInfo.SessionID, out hToken)) TRUE 5 " + "\n");
LUID luid = new LUID();
// Security attibute structure used in DuplicateTokenEx and CreateProcessAsUser
// I would prefer to not have to use a security attribute variable and to just
// simply pass null and inherit (by default) the security attributes
// of the existing token. However, in C# structures are value types and therefore
// cannot be assigned the null value.
SECURITY_ATTRIBUTES sa = new SECURITY_ATTRIBUTES();
sa.Length = Marshal.SizeOf(sa);
//if (DuplicateToken(hToken, SecurityImpersonation, ref hTokenDuplicate) != 0)
if (DuplicateTokenEx(hToken, MAXIMUM_ALLOWED/*GENERIC_ACCESS*/, ref sa,
(int)SECURITY_IMPERSONATION_LEVEL.SecurityIdentification,
(int)TOKEN_TYPE.TokenPrimary, out/*ref*/ hTokenDuplicate))
{
File.AppendAllText(tmp_log, "\n" + " DuplicateTokenEx() TRUE 6 " + "\n");
WindowsImpersonationContext m_ImpersonationContext;
m_ImpersonatedUser = new WindowsIdentity(hTokenDuplicate);
using (m_ImpersonationContext = m_ImpersonatedUser.Impersonate())
{
if (m_ImpersonationContext != null)
{
File.AppendAllText(tmp_log, Environment.NewLine + "User Name: " +
WindowsIdentity.GetCurrent(TokenAccessLevels.MaximumAllowed).Name +
Environment.NewLine + "SID: " +
WindowsIdentity.GetCurrent(TokenAccessLevels.MaximumAllowed).User.Value);
TOKEN_PRIVILEGES tp = new TOKEN_PRIVILEGES
{
PrivilegeCount = 1,
Privileges = new Int32[3]
};
tp.Privileges[1] = luid.HighPart;
tp.Privileges[0] = luid.LowPart;
tp.Privileges[2] = SE_PRIVILEGE_ENABLED;
//Adjust Token privilege
if (SetTokenInformation(hTokenDuplicate,
TOKEN_INFORMATION_CLASS.TokenSessionId,
ref tSessionInfo.SessionID,
(UInt32)Marshal.SizeOf(tSessionInfo.SessionID)))
{
File.AppendAllText(tmp_log, "\n" + " SetTokenInformation() TRUE 7 " + "\n");
if (AdjustTokenPrivileges(hTokenDuplicate,
false, ref tp, Marshal.SizeOf(tp),
IntPtr.Zero, IntPtr.Zero))
{
File.AppendAllText(tmp_log, "\n" + " AdjustTokenPrivileges() TRUE 8 " + "\n");
//ImpersonateLoggedOnUser(hToken);
//WindowsIdentity.Impersonate(hToken);
//errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
//File.AppendAllText(tmp_log, "\n" + "LaunchChildProcess-ImpersonateLoggedOnUser-" + errorMessage + "\n");
// Launch the child process interactively
// with the token of the logged-on user.
PROCESS_INFORMATION tProcessInfo;
STARTUPINFO tStartUpInfo = new STARTUPINFO();
tStartUpInfo.cb = Marshal.SizeOf(typeof(STARTUPINFO));
tStartUpInfo.lpDesktop = @"winsta0\default"; // interactive window station parameter; basically this indicates that the process created can display a GUI on the desktop
// flags that specify the priority and creation method of the process
int dwCreationFlags = NORMAL_PRIORITY_CLASS | CREATE_NEW_CONSOLE;
IntPtr pEnv = IntPtr.Zero;
if (CreateEnvironmentBlock(ref pEnv, hTokenDuplicate, true))
{
dwCreationFlags |= CREATE_UNICODE_ENVIRONMENT;
File.AppendAllText(tmp_log, "\n" + " CreateEnvironmentBlock() TRUE 9 " + "\n");
}
else
{
pEnv = IntPtr.Zero;
File.AppendAllText(tmp_log, "\n" + " CreateEnvironmentBlock() ELSE 9 " + "\n");
}
// create a new process in the current user's logon session
bool ChildProcStarted = CreateProcessAsUser(
hTokenDuplicate, // client's access token
ChildProcName, // file to execute
null, // command line
ref sa, // pointer to process SECURITY_ATTRIBUTES
ref sa, // pointer to thread SECURITY_ATTRIBUTES
false, // handles are not inheritable
dwCreationFlags, // creation flags
IntPtr.Zero, // pointer to new environment block
null, // name of current directory
ref tStartUpInfo, // pointer to STARTUPINFO structure
out tProcessInfo // receives information about new process
);
/*bool ChildProcStarted = CreateProcessAsUser(
//hToken, // Token of the logged-on user.
hTokenDuplicate, // Token of the logged-on user.
ChildProcName, // Name of the process to be started.
null, // Any command line arguments to be passed.
IntPtr.Zero, // Default Process' attributes.
IntPtr.Zero, // Default Thread's attributes.
false, // Does NOT inherit parent's handles.
0, // No any specific creation flag.
null, // Default environment path.
null, // Default current directory.
ref tStartUpInfo, // Process Startup Info.
out tProcessInfo // Process information to be returned.
);*/
errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
File.AppendAllText(tmp_log, "\n" + "LaunchChildProcess-CreateProcessAsUser-" + errorMessage + "\n");
if (ChildProcStarted)
{
// The child process creation is successful!
// If the child process is created, it can be controlled via the out
// param "tProcessInfo". For now, as we don't want to do any thing
// with the child process, closing the child process' handles
// to prevent the handle leak.
CloseHandle(tProcessInfo.hThread);
CloseHandle(tProcessInfo.hProcess);
File.AppendAllText(tmp_log, "\n" + "ChildProcStarted() 10 true!" + "\n");
}
else
{
// CreateProcessAsUser failed!
errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
File.AppendAllText(tmp_log, "\n" + " ChildProcStarted() 10 failed! ERROR: " + errorMessage + "\n");
}
// Whether child process was created or not, close the token handle
// and break the loop as processing for current active user has been done.
CloseHandle(hToken);
CloseHandle(hTokenDuplicate);
// Undo impersonation
//m_ImpersonationContext.Undo();
break;
}
else
{
errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
File.AppendAllText(tmp_log, "\n" + " AdjustTokenPrivileges() FALSE 8 ERROR: " + errorMessage + "\n");
}
}
else
{
errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
//File.AppendAllText(tmp_log, "\n" + "LaunchChildProcess-ImpersonateLoggedOnUser-" + errorMessage + "\n");
File.AppendAllText(tmp_log, "\n" + " SetTokenInformation() FALSE 7 ERROR: " + errorMessage + "\n");
}
}
}
}
else
{
errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
File.AppendAllText(tmp_log, "\n" + "DuplicateTokenEx() FALSE 6 ERROR: " + errorMessage + "\n");
}
}
else
{
// WTSQueryUserToken failed!
errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
File.AppendAllText(tmp_log, "\n" + "if (WTSQueryUserToken(tSessionInfo.SessionID, out hToken)) FALSE 5 ERROR: " + errorMessage + "\n");
}
}
else
{
errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
File.AppendAllText(tmp_log, "\n" + "RevertToSelf() FALSE 4 ERROR: " + errorMessage + "\n");
}
}
else
{
// This Session is not active!
errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
File.AppendAllText(tmp_log, "\n" + "if (WTS_CONNECTSTATE_CLASS.WTSActive == tSessionInfo.State) FALSE 3 This Session is not active! ERROR: " + errorMessage + "\n");
}
}
// Free the memory allocated for the session info array.
WTSFreeMemory(ppSessionInfo);
}
else
{
// WTSEnumerateSessions failed!
errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
File.AppendAllText(tmp_log, "\n" + "WTSEnumerateSessions FAILED 2 ERROR: " + errorMessage + "\n");
}
}
#region P/Invoke WTS APIs
/// <summary>
/// Struct, Enum and P/Invoke Declarations of WTS APIs.
/// </summary>
///
private const int WTS_CURRENT_SERVER_HANDLE = 0;
private enum WTS_CONNECTSTATE_CLASS
{
WTSActive,
WTSConnected,
WTSConnectQuery,
WTSShadow,
WTSDisconnected,
WTSIdle,
WTSListen,
WTSReset,
WTSDown,
WTSInit
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
private struct WTS_SESSION_INFO
{
public UInt32 SessionID;
public string pWinStationName;
public WTS_CONNECTSTATE_CLASS State;
}
[DllImport("WTSAPI32.DLL", SetLastError = true, CharSet = CharSet.Auto)]
static extern bool WTSEnumerateSessions(
IntPtr hServer,
[MarshalAs(UnmanagedType.U4)] UInt32 Reserved,
[MarshalAs(UnmanagedType.U4)] UInt32 Version,
ref IntPtr ppSessionInfo,
[MarshalAs(UnmanagedType.U4)] ref UInt32 pSessionInfoCount
);
[DllImport("WTSAPI32.DLL", SetLastError = true, CharSet = CharSet.Auto)]
static extern void WTSFreeMemory(IntPtr pMemory);
[DllImport("WTSAPI32.DLL", SetLastError = true, CharSet = CharSet.Auto)]
static extern bool WTSQueryUserToken(UInt32 sessionId, out IntPtr Token);
#endregion
#region P/Invoke CreateProcessAsUser
/// <summary>
/// Struct, Enum and P/Invoke Declarations for CreateProcessAsUser.
/// </summary>
///
#region WMI Constants
private const String cstrScope = "root\\CIMV2";
private const String cstrLoggenInUser = "SELECT * FROM Win32_ComputerSystem";
#endregion
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
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, CharSet = CharSet.Auto)]
public struct PROCESS_INFORMATION
{
public IntPtr hProcess;
public IntPtr hThread;
public int dwProcessId;
public int dwThreadId;
}
[StructLayout(LayoutKind.Sequential)]
public struct SECURITY_ATTRIBUTES
{
public int Length;
public IntPtr lpSecurityDescriptor;
public bool bInheritHandle;
}
#region Enumerations
enum TOKEN_INFORMATION_CLASS
{
TokenUser = 1,
TokenGroups,
TokenPrivileges,
TokenOwner,
TokenPrimaryGroup,
TokenDefaultDacl,
TokenSource,
TokenType,
TokenImpersonationLevel,
TokenStatistics,
TokenRestrictedSids,
TokenSessionId,
TokenGroupsAndPrivileges,
TokenSessionReference,
TokenSandBoxInert,
TokenAuditPolicy,
TokenOrigin,
MaxTokenInfoClass // MaxTokenInfoClass should always be the last enum
}
enum TOKEN_TYPE : int
{
TokenPrimary = 1,
TokenImpersonation = 2
}
enum SECURITY_IMPERSONATION_LEVEL : int
{
SecurityAnonymous = 0,
SecurityIdentification = 1,
SecurityImpersonation = 2,
SecurityDelegation = 3,
}
[StructLayout(LayoutKind.Sequential)]
public struct LUID
{
public Int32 LowPart;
public Int32 HighPart;
}
[StructLayout(LayoutKind.Sequential)]
public struct LUID_AND_ATRIBUTES
{
LUID Luid;
Int32 Attributes;
}
[StructLayout(LayoutKind.Sequential)]
struct TOKEN_PRIVILEGES
{
public Int32 PrivilegeCount;
//LUID_AND_ATRIBUTES
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
public Int32[] Privileges;
}
#endregion
#region Constants
public const uint GENERIC_ACCESS = 0x1000000;
public const uint MAXIMUM_ALLOWED = 0x2000000;
public const int CREATE_NEW_CONSOLE = 0x00000010;
public const int IDLE_PRIORITY_CLASS = 0x40;
public const int NORMAL_PRIORITY_CLASS = 0x20;
public const int HIGH_PRIORITY_CLASS = 0x80;
public const int REALTIME_PRIORITY_CLASS = 0x100;
const Int32 READ_CONTROL = 0x00020000;
const Int32 STANDARD_RIGHTS_REQUIRED = 0x000F0000;
const Int32 STANDARD_RIGHTS_READ = READ_CONTROL;
const Int32 STANDARD_RIGHTS_WRITE = READ_CONTROL;
const Int32 STANDARD_RIGHTS_EXECUTE = READ_CONTROL;
const Int32 STANDARD_RIGHTS_ALL = 0x001F0000;
const Int32 SPECIFIC_RIGHTS_ALL = 0x0000FFFF;
const Int32 TOKEN_ASSIGN_PRIMARY = 0x0001;
const Int32 TOKEN_DUPLICATE = 0x0002;
const Int32 TOKEN_IMPERSONATE = 0x0004;
const Int32 TOKEN_QUERY = 0x0008;
const Int32 TOKEN_QUERY_SOURCE = 0x0010;
const Int32 TOKEN_ADJUST_PRIVILEGES = 0x0020;
const Int32 TOKEN_ADJUST_GROUPS = 0x0040;
const Int32 TOKEN_ADJUST_DEFAULT = 0x0080;
const Int32 TOKEN_ADJUST_SESSIONID = 0x0100;
const Int32 TOKEN_ALL_ACCESS_P = (
STANDARD_RIGHTS_REQUIRED |
TOKEN_ASSIGN_PRIMARY |
TOKEN_DUPLICATE |
TOKEN_IMPERSONATE |
TOKEN_QUERY |
TOKEN_QUERY_SOURCE |
TOKEN_ADJUST_PRIVILEGES |
TOKEN_ADJUST_GROUPS |
TOKEN_ADJUST_DEFAULT);
const Int32 TOKEN_ALL_ACCESS = TOKEN_ALL_ACCESS_P | TOKEN_ADJUST_SESSIONID;
const Int32 TOKEN_READ = STANDARD_RIGHTS_READ | TOKEN_QUERY;
const Int32 TOKEN_WRITE = STANDARD_RIGHTS_WRITE |
TOKEN_ADJUST_PRIVILEGES |
TOKEN_ADJUST_GROUPS |
TOKEN_ADJUST_DEFAULT;
const Int32 TOKEN_EXECUTE = STANDARD_RIGHTS_EXECUTE;
//const UInt32 MAXIMUM_ALLOWED = 0x2000000;
const Int32 CREATE_NEW_PROCESS_GROUP = 0x00000200;
const Int32 CREATE_UNICODE_ENVIRONMENT = 0x00000400;
/*const Int32 IDLE_PRIORITY_CLASS = 0x40;
const Int32 NORMAL_PRIORITY_CLASS = 0x20;
const Int32 HIGH_PRIORITY_CLASS = 0x80;
const Int32 REALTIME_PRIORITY_CLASS = 0x100;*/
//const Int32 CREATE_NEW_CONSOLE = 0x00000010;
const string SE_DEBUG_NAME = "SeDebugPrivilege";
const string SE_RESTORE_NAME = "SeRestorePrivilege";
const string SE_BACKUP_NAME = "SeBackupPrivilege";
const Int32 SE_PRIVILEGE_ENABLED = 0x0002;
const Int32 ERROR_NOT_ALL_ASSIGNED = 1300;
[StructLayout(LayoutKind.Sequential)]
struct PROCESSENTRY32
{
UInt32 dwSize;
UInt32 cntUsage;
UInt32 th32ProcessID;
IntPtr th32DefaultHeapID;
UInt32 th32ModuleID;
UInt32 cntThreads;
UInt32 th32ParentProcessID;
Int32 pcPriClassBase;
UInt32 dwFlags;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
string szExeFile;
}
const UInt32 TH32CS_SNAPPROCESS = 0x00000002;
const Int32 INVALID_HANDLE_VALUE = -1;
#endregion
/* [DllImport("ADVAPI32.DLL", SetLastError = true, CharSet = CharSet.Auto)]
static extern bool CreateProcessAsUser(
IntPtr hToken,
string lpApplicationName,
string lpCommandLine,
IntPtr lpProcessAttributes,
IntPtr lpThreadAttributes,
bool bInheritHandles,
uint dwCreationFlags,
string lpEnvironment,
string lpCurrentDirectory,
ref STARTUPINFO lpStartupInfo,
out PROCESS_INFORMATION lpProcessInformation
);*/
[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("KERNEL32.DLL", SetLastError = true, CharSet = CharSet.Auto)]
static extern bool CloseHandle(IntPtr hHandle);
#endregion
[DllImport("kernel32.dll")]
public static extern UInt32 WTSGetActiveConsoleSessionId();
[DllImport("advapi32.dll", SetLastError = true)]
static extern Boolean LookupPrivilegeValue(IntPtr lpSystemName, string lpname, [MarshalAs(UnmanagedType.Struct)] ref LUID lpLuid);
[DllImport("advapi32.dll", SetLastError = true)]
static extern Boolean AdjustTokenPrivileges(IntPtr TokenHandle, Boolean DisableAllPrivileges, ref TOKEN_PRIVILEGES NewState, Int32 BufferLength, IntPtr PreviousState, IntPtr ReturnLength);
[DllImport("advapi32.dll", SetLastError = true)]
static extern Boolean SetTokenInformation(IntPtr TokenHandle, TOKEN_INFORMATION_CLASS TokenInformationClass, ref UInt32 TokenInformation, UInt32 TokenInformationLength);
[DllImport("userenv.dll", SetLastError = true)]
static extern Boolean CreateEnvironmentBlock(ref IntPtr lpEnvironment, IntPtr hToken, Boolean bInherit);
[DllImport("advapi32.DLL")]
public static extern bool ImpersonateLoggedOnUser(IntPtr hToken); //handle to token for logged-on user
[DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern int DuplicateToken(IntPtr hToken, int impersonationLevel, ref IntPtr hNewToken);
[DllImport("advapi32.dll", EntryPoint = "DuplicateTokenEx")]
public static extern bool DuplicateTokenEx(IntPtr ExistingTokenHandle, uint dwDesiredAccess,
ref SECURITY_ATTRIBUTES lpThreadAttributes, int TokenType,
int ImpersonationLevel, out/*ref*/ IntPtr DuplicateTokenHandle);
///
/// A process should call the RevertToSelf function after finishing
/// any impersonation begun by using the DdeImpersonateClient,
/// ImpersonateDdeClientWindow, ImpersonateLoggedOnUser, ImpersonateNamedPipeClient,
/// ImpersonateSelf, ImpersonateAnonymousToken or SetThreadToken function.
/// If RevertToSelf fails, your application continues to run in the context of the client,
/// which is not appropriate. You should shut down the process if RevertToSelf fails.
/// RevertToSelf Function: http://msdn.microsoft.com/en-us/library/aa379317(VS.85).aspx
///
/// A boolean value indicates the function succeeded or not.
[DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern bool RevertToSelf();
[DllImport("shell32.dll")]
public static extern bool SHGetSpecialFolderPath(IntPtr hwndOwner, [Out]StringBuilder lpszPath, int nFolder, bool fCreate);
static string System32_SysWOW64_Folder()
{
StringBuilder path = new StringBuilder(260);
SHGetSpecialFolderPath(IntPtr.Zero, path, 0x0029, false);
return path.ToString();
}
//=================== Create directory =====================
private static string CreateDirectoryAtSystemFolder()
{
string tmpDir = null;
string sysFolderPath = System32_SysWOW64_Folder();
//string sysFolderPath = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData); //System32_SysWOW64_Folder();
//string sysFolderPath = Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles); //ProgramFiles_Folder();
tmpDir = sysFolderPath + "\\logdata"; //ConfigurationSettings.AppSettings["ImageSavedPath"].ToString();
if (!System.IO.Directory.Exists(@tmpDir))
{
System.IO.Directory.CreateDirectory(@tmpDir);
}
return tmpDir;
}
}
}
As I mentioned in my earlier edit, previously before adding DuplicateTokenEx & SetTokenInformation, the service was able to run the app but it could not log under System32 folder. To achieve that I updated to the above code and now the SetTokenInformation() method shows the privilege error.
Edit: Finally the service could start my process on logged on user account and write all my log files at proper user appdata path. I have removed SetTokenInformation. Following code with CreateEnvironmentBlock() method helped the process get a separate user environment and retrieve the user appdata path.
int dwCreationFlags = DETACHED_PROCESS;
IntPtr pEnv = IntPtr.Zero;
if (CreateEnvironmentBlock(ref pEnv, hToken, true))
{
dwCreationFlags |= CREATE_UNICODE_ENVIRONMENT;
}
else
{
pEnv = IntPtr.Zero;
}
bool ChildProcStarted = CreateProcessAsUser(
hToken, // client's access token
ChildProcName, // file to execute
null, // command line
ref saProcess, // pointer to process SECURITY_ATTRIBUTES
ref saThread, // pointer to thread SECURITY_ATTRIBUTES
false, // handles are not inheritable
dwCreationFlags, // creation flags
pEnv, // pointer to new environment block
null, // name of current directory
ref tStartUpInfo, // pointer to STARTUPINFO structure
out tProcessInfo // receives information about new process
);
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To summarize:
The original problem was that the target executable was configured to require UAC elevation, but must be run in the user's context, even if the user is not an administrator. This isn't directly related to the fact that it was being launched from a service, but that was a complicating factor because it meant that the attempt to launch the application failed rather than resulting in an elevation dialog. The resolution was to change requestedExecutionLevel in the application's manifest from requireAdministrator to asInvoker which is the default value.
When the application was reconfigured to not require UAC elevation, it failed to run properly because it was trying to write log files to a global folder. The resolution was to write the log files to a suitable per-user location.
The last issue was that the application was not finding the per-user location correctly when launched from the service. This was because it was being given a copy of the service's environment block rather than one suitable to the user. The resolution was to use CreateEnvironmentBlock() to generate a suitable environment block and pass it as CreateProcessAsUser's lpEnvironment argument.
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