Hello!
I have an ASP.NET application (1.1 framework) that needs to be able to
read/write files on a network share. The access to this file share
will be fairly restricted, so I need to impersonate a specific user
account on our domain in order to gain access. The impersonation is
only needed for the sections that reads/writes files. I have tried
using the code from http://support.microsoft.com/default...N-US;Q306158#4
and many other similar sources with no success. I do not get any
errors, but I am not logged in using the username and passoword I
provide so I cannot access the network (it remains the anonymous
user). I have tried putting the impersonation code into a Class
Library and calling that from the web application with the same
results.
I must be doing something wrong. Any help would be appreciated.
(see code snippets below - irrelevant code has been removed)
Thank you,
Michelle
** CLASS LIBRARY **
****************************
Imports System.IO
Imports System.String
Imports System.Security.Principal
Imports System.Security
Public Class PerformanceReviewAttachment
Private Shared LOGON32_LOGON_INTERACTIVE As Integer = 2
Private Shared LOGON32_PROVIDER_DEFAULT As Integer = 0
Private Shared impersonationContext As WindowsImpersonationContext
Declare Function LogonUserA Lib "advapi32.dll" (ByVal lpszUsername
As String, _
ByVal lpszDomain As String, _
ByVal lpszPassword As String, _
ByVal dwLogonType As Integer, _
ByVal dwLogonProvider As Integer, _
ByRef phToken As IntPtr) As Integer
Declare Auto Function DuplicateToken Lib "advapi32.dll" ( _
ByVal ExistingTokenHandle As IntPtr, _
ByVal ImpersonationLevel As Integer, _
ByRef DuplicateTokenHandle As IntPtr) As
Integer
Declare Auto Function RevertToSelf Lib "advapi32.dll" () As Long
Declare Auto Function CloseHandle Lib "kernel32.dll" (ByVal handle
As IntPtr) As Long
Shared Function impersonateValidUser(ByVal userName As String,
ByVal domain As String, ByVal password As String) As Boolean
Dim tempWindowsIdentity As WindowsIdentity
Dim token As IntPtr = IntPtr.Zero
Dim tokenDuplicate As IntPtr = IntPtr.Zero
impersonateValidUser = False
If RevertToSelf() <> 0 Then
If LogonUserA(userName, domain, password,
LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT, token) <> 0 Then
If DuplicateToken(token, 2, tokenDuplicate) <> 0 Then
tempWindowsIdentity = New
WindowsIdentity(tokenDuplicate)
impersonationContext =
tempWindowsIdentity.Impersonate()
If Not impersonationContext Is Nothing Then
impersonateValidUser = True
End If
End If
End If
End If
If Not tokenDuplicate.Equals(IntPtr.Zero) Then
CloseHandle(tokenDuplicate)
End If
If Not token.Equals(IntPtr.Zero) Then
CloseHandle(token)
End If
End Function
Shared Sub undoImpersonation()
impersonationContext.Undo()
End Sub
End Class
** WEB FORM **
****************************
Private Sub Submit1_ServerClick(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles Submit1.ServerClick
Try
If classLibrary.impersonateValidUser("user",
"domain", "pwd") Then
File1.PostedFile.SaveAs(strFileName)
classLibrary.undoImpersonation()
Else
Throw New ApplicationException("Failed")
End If
Catch Ex As Exception
lblErrorMessage.Text = ex.Message
End Try
End Sub
