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VB.NET Private Sub AdjustToken() Const TOKEN_ADJUST_PRIVILEGES As Short = &H20S Const TOKEN_QUERY As Short = &H8S Const SE_PRIVILEGE_ENABLED As Short = &H2S Dim hdlProcessHandle As Integer Dim hdlTokenHandle As Integer Dim tmpLuid As LUID Dim tkp As TOKEN_PRIVILEGES Dim tkpNewButIgnored As TOKEN_PRIVILEGES Dim lBufferNeeded As Integer hdlProcessHandle = GetCurrentProcess() OpenProcessToken(hdlProcessHandle,TOKEN_ADJUST_PRIVILEGES Or TOKEN_QUERY, _ hdlTokenHandle) LookupPrivilegeValue("", "SeShutdownPrivilege", tmpLuid) tkp.PrivilegeCount = 1 ' One privilege to set tkp.TheLuid = tmpLuid tkp.Attributes = SE_PRIVILEGE_ENABLED AdjustTokenPrivileges(hdlTokenHandle,False, tkp, Len(tkpNewButIgnored), _ tkpNewButIgnored, lBufferNeeded) End Sub Going through this code in a bit more detail, we can break the process down into a number of steps. Privileges are granted or revoked on a process-by-process basis, thus the first step is to ascertain the process ID of the current process, using the GetCurrentProcess API call. To change the privilege levels for this process, it is necessary to open the process first. Opening the process involves passing the process ID to the OpenProcessToken API call. This call also includes parameters that indicate the purpose of opening the process, in this case, the purpose is to query the token, and adjust its privileges There is only one specific privilege that needs to be changed, - that being the shutdown privilege. The lookupPrivilegeValue is used to obtain a reference to the shutdown privilege. The TOKEN_PRIVILIGES structure is set to enabled, and then applied to the process. In order to make calls to windows API functions, they must be declared in advance. This tells .NET where to look for the implementation of each of the functions, in each case they will be contained in a DLL in the Windows system folder. These files are common to all windows PC’s and therefore do not need to be redistributed when deploying your application. C# [StructLayout(LayoutKind.Sequential, Pack=1)] internal struct TOKEN_PRIVILEGES { public int Count; public long Luid; public int Attr; }
internal const int EWX_SHUTDOWN = 0x00000001; internal const int EWX_REBOOT = 0x00000002; internal const int EWX_FORCE = 0x00000004;
[DllImport("kernel32.dll", ExactSpelling=true) ] internal static extern IntPtr GetCurrentProcess();
[DllImport("advapi32.dll", ExactSpelling=true, SetLastError=true) ] internal static extern bool OpenProcessToken( IntPtr h, int acc, ref IntPtr phtok );
[DllImport("advapi32.dll", SetLastError=true) ] internal static extern bool LookupPrivilegeValue( string host, string name, ref long pluid );
[DllImport("advapi32.dll", ExactSpelling=true, SetLastError=true) ] internal static extern bool AdjustTokenPrivileges( IntPtr htok, bool disall, ref TOKEN_PRIVILEGES newst, int len, IntPtr prev, IntPtr relen );
[DllImport("user32.dll", ExactSpelling=true, SetLastError=true) ] internal static extern bool ExitWindowsEx( int flg, int rea );
internal const int SE_PRIVILEGE_ENABLED = 0x00000002; internal const int TOKEN_QUERY = 0x00000008; internal const int TOKEN_ADJUST_PRIVILEGES = 0x00000020; internal const string SE_SHUTDOWN_NAME = "SeShutdownPrivilege"; VB.NET Private Structure LUID Dim UsedPart As Integer Dim IgnoredForNowHigh32BitPart As Integer End Structure
Private Structure TOKEN_PRIVILEGES Dim PrivilegeCount As Integer Dim TheLuid As Form1.LUID Dim Attributes As Integer End Structure
Private Const EWX_SHUTDOWN As Integer = 1 Private Const EWX_FORCE As Integer = 4 Private Const EWX_REBOOT As Short = 2 Page 2 Page 4Copyright 2012 Open Merchant Account Ltd. 
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