I am posting at the end of this post some code that P/Invoke's
SetSystemTime to set the local system time. This call fails -- i.e
the time is not set and the API returns false. However calling
Marshal.GetLast Win32Error immediately afterwards returns an errorcode
of 0 indicating that the operation somehow executed successfully.
This is a plain vanilla console app written in C#. It runs on vista
and has a manifest embedded in it that has 'requireAdminis trator'
privilege level on it. The logged on user belongs to the
administrator group and the UAC is set at "prompt for consent".
What am I missing? (FWIW, I didn't write the P/Invoke signatures
myself. I just lifted them out of various postings on the internet --
is there a mistake in that somewhere)?
It seems similar to what was reported here:
/********** CODE *************** *****/
using System;
using System.Collecti ons.Generic;
using System.Text;
using System.Runtime. InteropServices ;
using System.Componen tModel;
namespace VistaUACTest
{
class Program
{
[StructLayoutAtt ribute(LayoutKi nd.Sequential)]
public struct SystemTime
{
public short year;
public short month;
public short dayOfWeek;
public short day;
public short hour;
public short minute;
public short second;
public short milliseconds;
}
[DllImport("kern el32.dll")]
private static extern bool SetLocalTime(re f SystemTime
systime);
[DllImport("kern el32.dll")]
private static extern bool SetSystemTime(r ef SystemTime
systime);
private const int ANYSIZE_ARRAY = 1;
private const string SE_SYSTEMTIME_N AME =
"SeSystemtimePr ivilege";
private const int SE_PRIVILEGE_EN ABLED = 0x00000002;
private const int TOKEN_QUERY = 0x0008;
private const int TOKEN_ADJUST_PR IVILEGES = 0x0020;
[StructLayout(La youtKind.Sequen tial)]
public struct LUID
{
public int LowPart;
public int HighPart;
}
[StructLayout(La youtKind.Sequen tial)]
public struct LUID_AND_ATTRIB UTES
{
public LUID Luid;
public int Attributes;
}
[StructLayout(La youtKind.Sequen tial)]
public struct TOKEN_PRIVILEGE S
{
public int PrivilegeCount;
[MarshalAs(Unman agedType.ByValA rray, SizeConst =
ANYSIZE_ARRAY)]
public LUID_AND_ATTRIB UTES[] Privileges;
}
[DllImport("adva pi32.dll", CharSet = CharSet.Auto)]
public static extern bool OpenProcessToke n(int ProcessHandle,
int DesiredAccess, ref int TokenHandle);
[DllImport("kern el32.dll", CharSet = CharSet.Auto)]
public static extern int GetCurrentProce ss();
[DllImport("adva pi32.dll", CharSet = CharSet.Auto)]
public static extern bool LookupPrivilege Value(string
lpSystemName, string lpName,
[MarshalAs(Unman agedType.Struct )] ref LUID lpLuid);
[DllImport("adva pi32.dll", CharSet = CharSet.Auto)]
public static extern bool AdjustTokenPriv ileges(int
TokenHandle,
int
DisableAllPrivi leges,
[MarshalAs(Unman agedType.Struct )] ref TOKEN_PRIVILEGE S NewState,
int
BufferLength,
[MarshalAs(Unman agedType.Struct )] ref TOKEN_PRIVILEGE S PreviousState,
ref
int ReturnLength);
static void Main(string[] args)
{
try
{
// because the docs for SetSystemTime says that the
SE_SYSTEMTIME_N AME privilege is disabled by default
// this call doesn't really help though
AdjustPrivilege s();
SystemTime st = new SystemTime();
st.hour = 10;
if (!SetSystemTime (ref st))
{
// the return value says the call failed, however
Marshal.GetLast Win32Error() says the previous P/Invoke operation
// completed successfully (the default ctor of
Win32Exception calls GetLastWin32Err or)
throw new Win32Exception( );
}
}
catch (Exception ex)
{
Console.WriteLi ne(ex);
}
Console.Read();
}
public static bool AdjustPrivilege s()
{
TOKEN_PRIVILEGE S tkNew = new TOKEN_PRIVILEGE S();
tkNew.Privilege s = new LUID_AND_ATTRIB UTES[ANYSIZE_ARRAY];
TOKEN_PRIVILEGE S tkOld = new TOKEN_PRIVILEGE S();
tkOld.Privilege s = new LUID_AND_ATTRIB UTES[ANYSIZE_ARRAY];
LUID luid = new LUID();
int token = -1;
int oldluidSize = 0;
if (LookupPrivileg eValue(null, SE_SYSTEMTIME_N AME, ref
luid))
{
if (OpenProcessTok en(GetCurrentPr ocess(),
TOKEN_ADJUST_PR IVILEGES | TOKEN_QUERY, ref token))
{
tkNew.Privilege Count = 1;
tkNew.Privilege s[0].Attributes =
SE_PRIVILEGE_EN ABLED;
tkNew.Privilege s[0].Luid = luid;
int luidSize =
Marshal.SizeOf( typeof(TOKEN_PR IVILEGES));
if (AdjustTokenPri vileges(token, 0, ref tkNew,
luidSize, ref tkOld, ref oldluidSize))
{
return true;
}
}
}
return false;
}
}
}
/************ CODE *************** *********/
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