Error after converting to vb.net from C# [duplicate] - vb.net

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VB.NET and sizeof
(3 answers)
Closed 8 years ago.
I am trying to convert the C# code given in this link. I got some errors after conversion, but i have corrected some. Still i get error for the line cbSize = sizeof(TOKEN_ELEVATION_TYPE)
The errors are:
'sizeof' is not declared. It may be inaccessible due to its protection level. D:\Desktop\WindowsApplication3\WindowsApplication3\Form1.vb 103 26 WindowsApplication3
'TOKEN_ELEVATION_TYPE' is a type and cannot be used as an expression. D:\Desktop\WindowsApplication3\WindowsApplication3\Form1.vb 103 33 WindowsApplication3
I tried using Len instead of sizeof, but the second error still exists. So can anyone help me to solve both errors. Below is the VB.NET code which has said error.
Imports System.Runtime.InteropServices
Imports System.Security.Principal
Imports System.ComponentModel
Public Class Form1
Public Const TOKEN_DUPLICATE As UInt32 = &H2
Public Const TOKEN_IMPERSONATE As UInt32 = &H4
Public Const TOKEN_QUERY As UInt32 = &H8
Public Declare Function GetTokenInformation Lib "advapi32.dll" ( _
ByVal TokenHandle As IntPtr, ByVal TokenInformationClass As TOKEN_INFORMATION_CLASS, _
ByVal TokenInformation As IntPtr, ByVal TokenInformationLength As System.UInt32, _
ByRef ReturnLength As System.UInt32) As Boolean
Declare Function DuplicateToken Lib "advapi32.dll" (ExistingTokenHandle As IntPtr, _
SECURITY_IMPERSONATION_LEVEL As Int16, ByRef DuplicateTokenHandle As IntPtr) _
As Boolean
Enum TOKEN_ELEVATION_TYPE
TokenElevationTypeDefault = 1
TokenElevationTypeFull
TokenElevationTypeLimited
End Enum
Public Enum TOKEN_INFORMATION_CLASS
TokenUser = 1
TokenGroups
TokenPrivileges
TokenOwner
TokenPrimaryGroup
TokenDefaultDacl
TokenSource
TokenType
TokenImpersonationLevel
TokenStatistics
TokenRestrictedSids
TokenSessionId
TokenGroupsAndPrivileges
TokenSessionReference
TokenSandBoxInert
TokenAuditPolicy
TokenOrigin
TokenElevationType
TokenLinkedToken
TokenElevation
TokenHasRestrictions
TokenAccessInformation
TokenVirtualizationAllowed
TokenVirtualizationEnabled
TokenIntegrityLevel
TokenUIAccess
TokenMandatoryPolicy
TokenLogonSid
MaxTokenInfoClass
' MaxTokenInfoClass should always be the last enum
End Enum
Public Enum SECURITY_IMPERSONATION_LEVEL
SecurityAnonymous
SecurityIdentification
SecurityImpersonation
SecurityDelegation
End Enum
Function IsAdmin() As Boolean
Dim identity = WindowsIdentity.GetCurrent()
Return (identity IsNot Nothing AndAlso New WindowsPrincipal(identity).IsInRole(WindowsBuiltInRole.Administrator))
End Function
''' <summary>
''' The function checks whether the primary access token of the process belongs
''' to user account that is a member of the local Administrators group, even if
''' it currently is not elevated.
''' </summary>
''' <returns>
''' Returns true if the primary access token of the process belongs to user
''' account that is a member of the local Administrators group. Returns false
''' if the token does not.
''' </returns>
Function CanBeAdmin() As Boolean
Dim fInAdminGroup As Boolean = False
Dim hToken As IntPtr = IntPtr.Zero
Dim hTokenToCheck As IntPtr = IntPtr.Zero
Dim pElevationType As IntPtr = IntPtr.Zero
Dim pLinkedToken As IntPtr = IntPtr.Zero
Dim cbSize As Integer = 0
If IsAdmin() Then
Return True
End If
Try
' Check the token for this user
hToken = WindowsIdentity.GetCurrent().Token
' Determine whether system is running Windows Vista or later operating
' systems (major version >= 6) because they support linked tokens, but
' previous versions (major version < 6) do not.
If Environment.OSVersion.Version.Major >= 6 Then
' Running Windows Vista or later (major version >= 6).
' Determine token type: limited, elevated, or default.
' Allocate a buffer for the elevation type information.
cbSize = sizeof(TOKEN_ELEVATION_TYPE)
Dim cbSizeuint As UInteger = Convert.ToUInt32(cbSize)
pElevationType = Marshal.AllocHGlobal(cbSize)
If pElevationType = IntPtr.Zero Then
Throw New Win32Exception(Marshal.GetLastWin32Error())
End If
' Retrieve token elevation type information.
If Not GetTokenInformation(hToken, TOKEN_INFORMATION_CLASS.TokenElevationType, pElevationType, cbSizeuint, cbSizeuint) Then
Throw New Win32Exception(Marshal.GetLastWin32Error())
End If
' Marshal the TOKEN_ELEVATION_TYPE enum from native to .NET.
Dim elevType As TOKEN_ELEVATION_TYPE = CType(Marshal.ReadInt32(pElevationType), TOKEN_ELEVATION_TYPE)
' If limited, get the linked elevated token for further check.
If elevType = TOKEN_ELEVATION_TYPE.TokenElevationTypeLimited Then
' Allocate a buffer for the linked token.
cbSize = IntPtr.Size
Dim cbSizeuint_ee As UInteger = Convert.ToUInt32(cbSize)
pLinkedToken = Marshal.AllocHGlobal(cbSize)
If pLinkedToken = IntPtr.Zero Then
Throw New Win32Exception(Marshal.GetLastWin32Error())
End If
' Get the linked token.
If Not GetTokenInformation(hToken, TOKEN_INFORMATION_CLASS.TokenLinkedToken, pLinkedToken, cbSizeuint_ee, cbSizeuint_ee) Then
Throw New Win32Exception(Marshal.GetLastWin32Error())
End If
' Marshal the linked token value from native to .NET.
hTokenToCheck = Marshal.ReadIntPtr(pLinkedToken)
End If
End If
' CheckTokenMembership requires an impersonation token. If we just got
' a linked token, it already is an impersonation token. If we did not
' get a linked token, duplicate the original into an impersonation
' token for CheckTokenMembership.
If hTokenToCheck = IntPtr.Zero Then
If Not DuplicateToken(hToken, CInt(SECURITY_IMPERSONATION_LEVEL.SecurityIdentification), hTokenToCheck) Then
Throw New Win32Exception(Marshal.GetLastWin32Error())
End If
End If
' Check if the token to be checked contains admin SID.
Dim id As New WindowsIdentity(hTokenToCheck)
Dim principal As New WindowsPrincipal(id)
fInAdminGroup = principal.IsInRole(WindowsBuiltInRole.Administrator)
Catch
Return False
Finally
' Centralized cleanup for all allocated resources.
If pElevationType <> IntPtr.Zero Then
Marshal.FreeHGlobal(pElevationType)
pElevationType = IntPtr.Zero
End If
If pLinkedToken <> IntPtr.Zero Then
Marshal.FreeHGlobal(pLinkedToken)
pLinkedToken = IntPtr.Zero
End If
End Try
Return fInAdminGroup
End Function
Private Sub Form1_Load(sender As Object, e As EventArgs)
If CanBeAdmin() Then
MessageBox.Show("admin")
Else
MessageBox.Show("not admin")
End If
End Sub
End Class

Answer 1

You can get the effect of C# cbSize = sizeof(TOKEN_ELEVATION_TYPE) using Marshal.SizeOf to get the size of the underlying type.
Dim undertype As Type = [Enum].GetUnderlyingType(GetType(TOKEN_ELEVATION_TYPE))
cbSize = System.Runtime.InteropServices.Marshal.SizeOf(undertype)
When I ran it, undertype was System.Int32, and cbSize was 4.