The following example demonstrates how to impersonate a user and then
revert
to the original identity.
[Visual Basic]
Imports System
Imports System.Runtime.InteropServices
Imports System.Security.Principal
Imports System.Security.Permissions
<Assembly:SecurityPermissionAttribute(SecurityActi on.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
"RTT" <RT*@pandora.be> wrote in message news:RT*@pandora.be:
i'm writing a windows form but codebased a iwant to run the code as a
different user.
like in a webapplication you can impersonate a user so the website does
not
run on the standard ASP.NET user.
is it possible to do the same for a windows form and define a user
codebased
and run the code like that user is running the application.
