CheckTokenMembership in VB6

Question

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.

Answer 1

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

Answer 2

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

Answer 3

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