Onderstaand stukje uit de MSDN
voor het complete artikel (als je de msdn hebt geinstalleerd) Kijken even naar IIdentity (WIndowsIdentity) en IPrincipal.
Success
ms-help://MS.VSCC/MS.MSDNVS/cpref/html/frlrfsystemsecurityprincipalwindowsidentityclassimpersonatetopic.htm
Imports System
Imports System.Runtime.InteropServices
Imports System.Security.Principal
Imports System.Security.Permissions
<Assembly:SecurityPermissionAttribute(SecurityAction.RequestMinimum, UnmanagedCode := true)>
Public Class Impersonation
<DllImport("C:\\WINNT\\System32\\advapi32.dll")> _
Public Shared Function LogonUser(lpszUsername As String, lpszDomain As String, lpszPassword As String, _
dwLogonType As Integer, dwLogonProvider As Integer, ByRef phToken As Integer) As Boolean
End Function
<DllImport("C:\\WINNT\\System32\\Kernel32.dll")> _
Public Shared Function GetLastError() As Integer
End Function
Public Shared Sub Main(args() As String)
'The Windows NT user token.
Dim token1 As Integer
'Get the user token for the specified user, machine, and password using the unmanaged LogonUser method.
'The parameters for LogonUser are the user name, computer name, password,
'Logon type (LOGON32_LOGON_NETWORK_CLEARTEXT), Logon provider (LOGON32_PROVIDER_DEFAULT),
'and user token.
Dim loggedOn As Boolean = LogonUser("bob", "AARDVARK", "coffee", 3, 0, token1)
Console.WriteLine("LogonUser called")
'Call GetLastError to try to determine why logon failed if it did not succeed.
Dim ret As Integer = GetLastError()
Console.WriteLine("LogonUser Success? " + loggedOn)
Console.WriteLine("NT Token Value: " + token1)
If ret <> 0 Then
Console.WriteLine("Error code (126 == ""Specified module could not be found""): " + ret)
End If
'Starting impersonation here:
Console.WriteLine("Before impersonation:")
Dim mWI1 As WindowsIdentity = WindowsIdentity.GetCurrent()
Console.WriteLine(mWI1.Name)
Console.WriteLine(mWI1.Token)
Dim token2 As IntPtr = new IntPtr(token1)
Console.WriteLine("New identity created:")
Dim mWI2 As WindowsIdentity = new WindowsIdentity(token2)
Console.WriteLine(mWI2.Name)
Console.WriteLine(mWI2.Token)
'Impersonate the user.
Dim mWIC As WindowsImpersonationContext = mWI2.Impersonate()
Console.WriteLine("After impersonation:")
Dim mWI3 As WindowsIdentity = WindowsIdentity.GetCurrent()
Console.WriteLine(mWI3.Name)
Console.WriteLine(mWI3.Token)
'Revert to previous identity.
mWIC.Undo()
Console.WriteLine("After impersonation is reverted:")
Dim mWI4 As WindowsIdentity = WindowsIdentity.GetCurrent()
Console.WriteLine(mWI4.Name)
Console.WriteLine(mWI4.Token)
End Sub
End Class
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