CheckTokenMembership in VB6 - winapi

I'm having a hard time converting this C++ code to VB6 code. I've search the net and haven't found anything. PInvoke.net only has reference to VB.NET code. Here's the code from MSDN:
BOOL IsUserAdmin(VOID)
/*++
Routine Description: This routine returns TRUE if the caller's
process is a member of the Administrators local group. Caller is NOT
expected to be impersonating anyone and is expected to be able to
open its own process and process token.
Arguments: None.
Return Value:
TRUE - Caller has Administrators local group.
FALSE - Caller does not have Administrators local group. --
*/
{
BOOL b;
SID_IDENTIFIER_AUTHORITY NtAuthority = SECURITY_NT_AUTHORITY;
PSID AdministratorsGroup;
b = AllocateAndInitializeSid(
&NtAuthority,
2,
SECURITY_BUILTIN_DOMAIN_RID,
DOMAIN_ALIAS_RID_ADMINS,
0, 0, 0, 0, 0, 0,
&AdministratorsGroup);
if(b)
{
if (!CheckTokenMembership( NULL, AdministratorsGroup, &b))
{
b = FALSE;
}
FreeSid(AdministratorsGroup);
}
return(b);
}
It would be great if somebody can help out in converting this to VB6 code.
Thanks!
EDIT:
I was originally going to use that function but MSDN says:
This function is a wrapper for CheckTokenMembership. It is recommended to call that function directly to determine Administrator group status rather than calling IsUserAnAdmin.

Try this
Option Explicit
Private Const SECURITY_BUILTIN_DOMAIN_RID As Long = &H20
Private Const DOMAIN_ALIAS_RID_ADMINS As Long = &H220
Private Declare Function AllocateAndInitializeSid Lib "advapi32.dll" (pIdentifierAuthority As Any, ByVal nSubAuthorityCount As Byte, ByVal nSubAuthority0 As Long, ByVal nSubAuthority1 As Long, ByVal nSubAuthority2 As Long, ByVal nSubAuthority3 As Long, ByVal nSubAuthority4 As Long, ByVal nSubAuthority5 As Long, ByVal nSubAuthority6 As Long, ByVal nSubAuthority7 As Long, lpPSid As Long) As Long
Private Declare Sub FreeSid Lib "advapi32.dll" (ByVal pSid As Long)
Private Declare Function CheckTokenMembership Lib "advapi32.dll" (ByVal hToken As Long, ByVal pSidToCheck As Long, pbIsMember As Long) As Long
Private Type SID_IDENTIFIER_AUTHORITY
Value(0 To 5) As Byte
End Type
Private Function pvIsAdmin() As Boolean
Dim uAuthNt As SID_IDENTIFIER_AUTHORITY
Dim pSidAdmins As Long
Dim lResult As Long
uAuthNt.Value(5) = 5
If AllocateAndInitializeSid(uAuthNt, 2, SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0, 0, 0, 0, pSidAdmins) <> 0 Then
If CheckTokenMembership(0, pSidAdmins, lResult) <> 0 Then
pvIsAdmin = (lResult <> 0)
End If
Call FreeSid(pSidAdmins)
End If
End Function

You've posted the MSDN sample code for CheckTokenMembership - it uses CheckTokenMembership to determine whether the user is an administrator.
In VB6 it's easier to use IsUserAnAdmin, which is a wrapper for CheckTokenMembership. The MSDN docs do say IsUserAnAdmin is deprecated, but it's so much easier to call than CheckTokenMembership.
Private Declare Function IsUserAnAdmin Lib "Shell32" Alias "#680" () As Integer
If IsUserAnAdmin() = 0 Then
MsgBox "Not admin"
Else
MsgBox "Admin"
End If

Unless there is a reason to convert the code, use the API
Private Declare Function IsUserAdmin Lib "Shell32" Alias "#680" () As Boolean
Private Sub Form_Load()
If IsUserAdmin Then MsgBox "User is Admin"
End Sub

Related

VB.net SendMessage with CB_ADDSTRING '0' not valid for 'index'

I'm trying to fasten up the loading of one form, which populates several combobox with a big amount of data. I did my best stopping the UI while loading ecc shredding the loading time from 20s to 13s, but still the only bottleneck remaining is loading data into ComboBox which takes about 3-4s each. I did research on the internet and found that using Windows API you can fasten it up a lot more. So I did the code:
Private Const CB_ERR As Integer = -1
Private Const CB_ADDSTRING As Integer = &H143
Private Const CB_SETITEMDATA As Integer = &H151
<DllImport("user32.dll", CharSet:=CharSet.Auto)>
Private Function SendMessage(ByVal hWnd As IntPtr, ByVal wMsg As Integer, ByVal wParam As Integer, lParam As String) As Integer
End Function
<DllImport("user32.dll", CharSet:=CharSet.Auto)>
Private Function SendMessage(ByVal hWnd As IntPtr, ByVal wMsg As Integer, ByVal wParam As Integer, lParam As Object) As Integer
End Function
Public Sub AddItem(cmb As ComboBox, Item As Object)
Dim l As Integer
l = SendMessage(cmb.Handle, CB_ADDSTRING, 0&, Item.ToString())
SendMessage(cmb.Handle, CB_SETITEMDATA, l, Item)
End Sub
But on CB_ADDSTRING the program crashes with this error (that can be catched):
InvalidArgument=Value of '0' not valid for 'index'. Parameter Name: index
Since I'm using Krypton Controls, I had to shuffle trough Parents until I found KryptonComboBox, and then pass it's Handle value.

VB6 sidebar app

All.
I'm attempting to develop a 'sidebar' application with vb6, which I want to behave like windows Vista's gadget sidebar or Google Desktop sidebar, in the respect that other windows could not maximize over it.
I'm aware that chances of this happening are probably very little, but I'm asking just in case.
Currently, I've got a form that has multiple controls, and runs a function on load which makes itself the exact height of the screen, minus the taskbar, and it's 'left' location is set by a timer to be 'screen.width - me.width', so it will start at full height on the far right of the screen, and cannot be moved. Code for the height is as follows, if it is necessary.
Declare Function GetUserNameA Lib "advapi32.dll" (ByVal lpBuffer As String, nSize As Long) As Long
Public Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" ( _
ByVal hwnd As Long, _
ByVal nIndex As Long) As Long
Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" ( _
ByVal hwnd As Long, _
ByVal nIndex As Long, _
ByVal dwNewLong As Long) As Long
Public Declare Function SetLayeredWindowAttributes Lib "user32" ( _
ByVal hwnd As Long, _
ByVal crKey As Long, _
ByVal bAlpha As Byte, _
ByVal dwFlags As Long) As Long
Public Const GWL_STYLE = (-16)
Public Const GWL_EXSTYLE = (-20)
Public Const WS_EX_LAYERED = &H80000
Public Const LWA_COLORKEY = &H1
Public Const LWA_ALPHA = &H2
Private Const ABM_GETTASKBARPOS = &H5
Private Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
Private Type APPBARDATA
cbSize As Long
hwnd As Long
uCallbackMessage As Long
uEdge As Long
rc As RECT
lParam As Long
End Type
Private Declare Function SHAppBarMessage Lib "shell32.dll" (ByVal dwMessage As Long, pData As APPBARDATA) As Long
Function Fixheight()
Dim ABD As APPBARDATA
SHAppBarMessage ABM_GETTASKBARPOS, ABD
Form1.Height = Screen.Height - ((ABD.rc.Bottom - ABD.rc.Top) * 12)
If Form1.Height <= 600 Then
Form1.Height = Screen.Height
End If
End Function
To be clear, I do not want an 'always on top' function. I already have that, and it's driving me insane, as the form has to me closed or minimized in order to maximize, minimize of close another program (i.e. chrome, word, etc) behind it. This form must instead not allow other programs to maximize over it, so that if for example, the user maximized Chrome, chrome would maximize minus form1.width.
I doubt that this is possible because as far as I'm concerned, that would mean taking control of chrome, and essentially making it's maximize function as
me.height = screen.height - ((ABD.rc.Bottom - ABD.rc.Top) * 12)
me.width = screen.width - form1.width
which isn't possible.
Anyway, hopefully someone out there can help. As I said, I seriously doubt the possibility of having this work, but if so, all the better.
Thanks in advance!
Thanks to Ken White, I googled SHAppBarMessage and found the following website, offering a downloadable source with the very feature I needed. I just have to implement it now!!
Very glad I asked! Thank you!
Edit: Found this spanish website, which while needed some help from Google Translate, is more suited to my needs. Just need to figure out how to make it work on the Right Hand Side! Thanks again!

How to get the Browser UserAgent String in Visual Basic 6?

I am trying to get the UserAgent of the default browser using the ObtainUserAgentString API in Visual Basic 6. I found the documentation on the MSDN and tried to convert it to Visual Basic 6 but it did not work.
C++ (MSDN)
HRESULT ObtainUserAgentString(
_In_ DWORD dwOption = 0,
_Out_ LPCSTR *pcszUAOut,
_Out_ DWORD *cbSize
);
Visual Basic 6 API
Private Declare Function ObtainUserAgentString Lib "Urlmon.dll" (ByVal dwOption As Long, ByRef pcszUAOut As String, ByRef cbSize As Long) As Long
Private Function BrowserUserAgent() As String
Dim httpUseragent As String
Dim szhttpUserAgent As Long
httpUseragent = Space(512)
szhttpUserAgent = Len(httpUseragent)
Call ObtainUserAgentString(0, httpUseragent, szhttpUserAgent)
BrowserUserAgent = httpUseragent
End Function
Private Sub Command1_Click()
MsgBox BrowserUserAgent
End Sub
Aside from the fact this is a cruddy old ANSI entrypoint, everything you need appears to be documented.
Option Explicit
Private Const NOERROR As Long = 0
Private Const E_OUTOFMEMORY As Long = &H8007000E
Private Enum UAS_OPTIONSENUM
[_UAS_EXACTLEGACY] = &H1000&
UAS_DEFAULT = 0
UAS_7 = 7 'Compatible mode.
UAS_7_LEGACY = 7 Or [_UAS_EXACTLEGACY]
UAS_8 = 8
UAS_9 = 9
UAS_10 = 10
UAS_11 = 11
End Enum
Private Declare Function ObtainUserAgentString Lib "urlmon" ( _
ByVal dwOption As Long, _
ByVal pcszUAOut As Long, _
ByRef cbSize As Long) As Long
Private Function BrowserUserAgent( _
Optional ByVal Options As UAS_OPTIONSENUM = UAS_DEFAULT) As String
Const MAX_BUFFER As Long = 2048
Dim Size As Long
Dim Buffer() As Byte
Dim HRESULT As Long
Do
Size = Size + 128
ReDim Buffer(Size - 1)
HRESULT = ObtainUserAgentString(Options, VarPtr(Buffer(0)), Size)
Loop While HRESULT = E_OUTOFMEMORY And Size < MAX_BUFFER
If HRESULT = NOERROR Then
BrowserUserAgent = StrConv(LeftB$(Buffer, Size - 1), vbUnicode)
Else
Err.Raise &H8004D000, _
, _
"ObtainUserAgentString error &H" & Hex$(HRESULT)
End If
End Function
Private Sub Form_Load()
AutoRedraw = True
Print BrowserUserAgent()
Print BrowserUserAgent(UAS_7)
Print BrowserUserAgent(UAS_7_LEGACY)
Print BrowserUserAgent(UAS_8)
Print BrowserUserAgent(UAS_11)
End Sub
HRESULT ObtainUserAgentString(
_In_ DWORD dwOption = 0,
_Out_ LPCSTR *pcszUAOut,
_Out_ DWORD *cbSize
);
Param 2 is LongPointerCString. You always pass C strings ByVal which in reality passes the C string part of the B String ByRef. If it was a IN param you would have to end the string with a Chr(0) which is what real C strings have.
String arguments are a special case. Passing a string by value means you are passing the address of the first data byte in the string; passing a string by reference means you are passing the memory address where another address is stored; the second address actually refers to the first data byte of the string. How you determine which approach to use is explained in the topic "Passing Strings to a DLL Procedure" later in this chapter.
From Visual Basic Concepts in Help.

VB6 WH_GETMESSAGE message hook

hello friends,i want to monitor an IP address control's(created by CreateWindowEx) input events which is on a form.i have used the API SetWindowsHookEx to hook WH_GETMESSAGE message ,but now i cannt eat the input message as (MSG)lParam->message = WM_NULL like in C,So i need your help,friends. can you give me the solution?
here is the code:
Private Function GetMsgProc(ByVal nCode As Long, ByVal wParam As Long, ByRef lParam As Long) As Long
CopyMemory p, ByVal lParam, LenB(p)
If p.message = WM_RBUTTONDOWN And GetParent(p.hWnd) = lngHWNDCtl Then
GetMsgProc = 0
Else
GetMsgProc = CallNextHookEx(hHook, nCode, wParam, ByVal lParam)
End If
End Function
Public Sub SetHook(ByVal lngThread As Long, lngHWND As Long, bFlag As Boolean)
If bFlag Then
lngHWNDCtl = lngHWND
hHook = SetWindowsHookEx(WH_GETMESSAGE, AddressOf GetMsgProc, 0, lngThread)
Else
If hHook Then UnhookWindowsHookEx hHook
End If
End Sub
Skipping the call to CallNextHookEx in GetMsgProc filter function is generally a bad idea. If you do this then other filter functions in the chain will not be called. Maybe, there are none on a dev machine, but 'in the wild' there will be other applications that installed hooks. Those applications will misbehave if you prevent their filter functions from being called.
You probably wouldn't want to analyze messages that have been merely peeked from the queue, but not removed from it. GetMsgProc is called with wParam = PM_REMOVE for messages that have been removed from queue.
VB6 or C++ or whatever, it is a deadly practice to ignore MSDN specification for API. This is how GetMsgProc filter function should make a decision based on a value of its first argument:
code [in]
Specifies whether the hook procedure must process the
message. If code is HC_ACTION, the hook procedure must process the
message. If code is less than zero, the hook procedure must pass the
message to the CallNextHookEx function without further processing and
should return the value returned by CallNextHookEx.
http://msdn.microsoft.com/en-us/library/windows/desktop/ms644981%28v=vs.85%29.aspx
Although CopyMemory should work (assuming you declare it correctly), I wouldn't bother with it here. It's perfectly OK to declare 3rd parameter of filter function as ByRef lParam As MSG.
Here is the code that should be placed in a standard module (as any other code that installs hooks). It works for me if I use it to sniff WM_RBUTTONDOWN messages to, say, TextBox control placed on a main form.
Option Explicit
'http://msdn.microsoft.com/en-us/library/windows/desktop/dd162805%28v=vs.85%29.aspx
Private Type tagPOINT
x As Long
y As Long
End Type
'http://msdn.microsoft.com/en-us/library/windows/desktop/ms644958%28v=vs.85%29.aspx
Private Type MSG
hWnd As Long
message As Long
wParam As Long
lParam As Long
time As Long
pt As tagPOINT
End Type
Private bHooked As Boolean
Private hHook As Long
Private hHwndToSniff As Long
Private Const HC_Action As Long = &H0
Private Const PM_NOREMOVE As Long = &H0
Private Const PM_REMOVE As Long = &H1
Private Const WH_GETMESSAGE As Long = &H3
Private Const WM_RBUTTONDOWN As Long = &H204
'http://msdn.microsoft.com/en-us/library/windows/desktop/ms644974%28v=vs.85%29.aspx
Private Declare Function CallNextHookEx Lib "user32" _
(ByVal hHook As Long, ByVal ncode As Long, ByVal wParam As Long, lParam As Any) As Long
'http://msdn.microsoft.com/en-us/library/windows/desktop/ms644990%28v=vs.85%29.aspx
Private Declare Function SetWindowsHookEx Lib "user32" _
Alias "SetWindowsHookExA" _
(ByVal idHook As Long, ByVal lpfn As Long, ByVal hmod As Long, ByVal dwThreadId As Long) As Long
'http://msdn.microsoft.com/en-us/library/windows/desktop/ms644993%28v=vs.85%29.aspx
Private Declare Function UnhookWindowsHookEx Lib "user32" _
(ByVal hHook As Long) As Long
Public Sub RemoveHook()
If bHooked Then
UnhookWindowsHookEx hHook
bHooked = False
End If
End Sub
Public Sub SetHook(ByVal hThreadToHook As Long, hHwndFilter As Long)
If Not bHooked Then
hHook = SetWindowsHookEx(WH_GETMESSAGE, AddressOf GetMsgProc, 0, hThreadToHook)
If hHook > 0 Then
bHooked = True
hHwndToSniff = hHwndFilter
Else
Debug.Assert False
End If
End If
End Sub
'http://msdn.microsoft.com/en-us/library/windows/desktop/ms644981%28v=vs.85%29.aspx
Private Function GetMsgProc(ByVal uCode As Long _
, ByVal wParam As Long _
, ByRef lParam As MSG) As Long
If uCode = 0 Then
If wParam = PM_REMOVE Then
If lParam.message = WM_RBUTTONDOWN Then
If lParam.hWnd = hHwndToSniff Then
MsgBox "You right-clicked a text box!"
End If
End If
End If
End If
GetMsgProc = CallNextHookEx(hHook, uCode, wParam, lParam)
End Function
The hook is installed in a form module in the following fashion:
SetHook App.ThreadID, Me.Text1.hWnd

VB6: Single-instance application across all user sessions

I have an application that needs to be a single-instance app across all user sessions on a Windows PC. My research thus far has centered around using a mutex to accomplish this, but I am having an issue that I am not sure is really an issue, this is really a best-practice question I believe.
Here's the code first of all:
Private Const AppVer = "Global\UNIQUENAME" ' This is not what i am using but the name is unique
Public Sub Main()
Dim mutexValue As Long
mutexValue = CreateMutex(ByVal 0&, 1, AppVer)
If (Err.LastDllError = ERROR_ALREADY_EXISTS) Then
SaveTitle$ = App.Title
App.Title = "... duplicate instance."
MsgBox "A duplicate instance of this program exists."
CloseHandle mutexValue
Exit Sub
End If
' Else keep on truckin'
Now, based on this article I believe I understand that by passing the NULL pointer to the CreateMutex function as I am above I'm basically assigning whatever security descriptor is associated with the currently logged in user.
If that means what I think it does (I may need more guidance here) that tells me that other users who log in will not be able to "see" the mutex created under the original user's session, nor will they be able to create a mutex with the same name.
Now, emperical evidence seems to back this up. I used a message box to pop the "LastDLLError" I was receiving, and when another user attempted to launch the application (while it was already running under another user account) I would receive an ERROR_ACCESS_DENIED code. I am OK with testing against this along with the ERROR_ALREADY_EXISTS code and just exiting on either/or. However, this feels sort of hackish and I'm wondering if someone can suggest an alternative. The "right" thing to do seems to be to pass the proper pointer to the CreateMutex function such that any user has the proper permissions to view any existing mutexes (mutices?), but I'm not so sure this is possible without the currently logged in user being an admin (which is unacceptible). Any assistance/guidance is greatly appreciated. Thanks in advance!
You don't need admin priveleges to set security on you own mutexes. Here is a simple demo app that basicly gives Everyone/Full control to the mutex.
Option Explicit
Private Const STANDARD_RIGHTS_REQUIRED As Long = &HF0000
Private Const SYNCHRONIZE As Long = &H100000
Private Const MUTANT_QUERY_STATE As Long = &H1
Private Const MUTANT_ALL_ACCESS As Long = (STANDARD_RIGHTS_REQUIRED Or SYNCHRONIZE Or MUTANT_QUERY_STATE)
Private Const SECURITY_DESCRIPTOR_REVISION As Long = 1
Private Const DACL_SECURITY_INFORMATION As Long = 4
Private Declare Function CreateMutex Lib "kernel32" Alias "CreateMutexA" (lpMutexAttributes As Any, ByVal bInitialOwner As Long, ByVal lpName As String) As Long
Private Declare Function OpenMutex Lib "kernel32" Alias "OpenMutexA" (ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, ByVal lpName As String) As Long
Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long
Private Declare Function InitializeSecurityDescriptor Lib "advapi32.dll" (pSecurityDescriptor As Any, ByVal dwRevision As Long) As Long
Private Declare Function SetSecurityDescriptorDacl Lib "advapi32.dll" (pSecurityDescriptor As Any, ByVal bDaclPresent As Long, pDacl As Any, ByVal bDaclDefaulted As Long) As Long
Private Declare Function SetKernelObjectSecurity Lib "advapi32.dll" (ByVal Handle As Long, ByVal SecurityInformation As Long, pSecurityDescriptor As SECURITY_DESCRIPTOR) As Long
Private Type SECURITY_DESCRIPTOR
Revision As Byte
Sbz1 As Byte
Control As Long
Owner As Long
Group As Long
pSacl As Long
pDacl As Long
End Type
Private Const MUTEX_NAME As String = "Global\20b70e57-1c2e-4de9-99e5-20f3961e6812"
Private m_hCurrentMutex As Long
Private Sub Form_Load()
Dim hMutex As Long
Dim uSec As SECURITY_DESCRIPTOR
hMutex = OpenMutex(MUTANT_ALL_ACCESS, 0, MUTEX_NAME)
If hMutex <> 0 Then
Call CloseHandle(hMutex)
MsgBox "Already running", vbExclamation
Unload Me
Exit Sub
End If
m_hCurrentMutex = CreateMutex(ByVal 0&, 1, MUTEX_NAME)
Call InitializeSecurityDescriptor(uSec, SECURITY_DESCRIPTOR_REVISION)
Call SetSecurityDescriptorDacl(uSec, 1, ByVal 0, 0)
Call SetKernelObjectSecurity(m_hCurrentMutex, DACL_SECURITY_INFORMATION, uSec)
End Sub
Private Sub Form_Unload(Cancel As Integer)
If m_hCurrentMutex <> 0 Then
Call CloseHandle(m_hCurrentMutex)
m_hCurrentMutex = 0
End If
End Sub
I was looking for a similar solution in VB6 late last year. At the time I was unable to find any examples of VB6 apps communicating across the user boundary, so I had to write my own.
See: Interprocess Communication via Semaphores
You can use the class to create and check for a global semaphore which will tell you if your app is already running under any user. I didn't look at the Mutex APIs but their usage is very similar. The GetSecurityDescriptor function is what you'll want to transpose if you've already got some Mutex code written.
I think your instincts are exactly right. I don't know any reason why it wouldn't be safe to infer from ERROR_ACCESS_DENIED that some other process has the mutex, so effectively it's the same as ERROR_ALREADY_EXISTS (in this context.) But at the same time, it doesn't feel quite right.
As you suggest, setting a proper security descriptor is indeed the right way to do it. MSDN says that granting MUTEX_ALL_ACCESS privileges increases the risk that the user will have to be an admin, and I think you do need MUTEX_ALL_ACCESS. But in my experience it works fine for non-admins.
Your question intrigued me enough do a quick test. That means I have some source code, and so here it is:
int wmain(int argc, wchar_t* argv[])
{
ACL *existing_dacl = NULL;
ACL *new_dacl = NULL;
PSECURITY_DESCRIPTOR security_descriptor = NULL;
bool owner = false;
HANDLE mutex = CreateMutex(NULL,FALSE,L"Global\\blah");
if(mutex == NULL)
wprintf(L"CreateMutex failed: 0x%08x\r\n",GetLastError());
if(GetLastError() == ERROR_ALREADY_EXISTS)
wprintf(L"Got handle to existing mutex\r\n");
else
{
wprintf(L"Created new mutex\r\n");
owner = true;
}
if(owner)
{
// Get the DACL on the mutex
HRESULT hr = GetSecurityInfo(mutex,SE_KERNEL_OBJECT,
DACL_SECURITY_INFORMATION,NULL,NULL,
&existing_dacl,NULL,
&security_descriptor);
if(hr != S_OK)
wprintf(L"GetSecurityInfo failed: 0x%08x\r\n",hr);
// Add an ACE to the ACL
EXPLICIT_ACCESSW ace;
memset(&ace,0,sizeof(ace));
ace.grfAccessPermissions = MUTEX_ALL_ACCESS;
ace.grfAccessMode = GRANT_ACCESS;
ace.grfInheritance = NO_INHERITANCE;
ace.Trustee.pMultipleTrustee = NULL;
ace.Trustee.MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE;
ace.Trustee.TrusteeForm = TRUSTEE_IS_NAME;
ace.Trustee.TrusteeType = TRUSTEE_IS_WELL_KNOWN_GROUP;
ace.Trustee.ptstrName = L"EVERYONE";
hr = SetEntriesInAcl(1,&ace,existing_dacl,&new_dacl);
if(hr != S_OK)
wprintf(L"SetEntriesInAcl failed: 0x%08x\r\n",hr);
// Set the modified DACL on the mutex
hr = SetSecurityInfo(mutex,SE_KERNEL_OBJECT,
DACL_SECURITY_INFORMATION,NULL,NULL,new_dacl,NULL);
if(hr != S_OK)
wprintf(L"SetSecurityInfo failed: 0x%08x\r\n",hr);
else
wprintf(L"Changed ACL\r\n");
LocalFree(existing_dacl);
LocalFree(new_dacl);
LocalFree(security_descriptor);
}
wprintf(L"Press any key...");
_getch();
CloseHandle(mutex);
return 0;
}

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