Authenticate against Windows NT/2000 Domain

Upload
'Place the following in your ASP page handling the server-side authetication.
'************************************************
<% Dim objADSI, strUsername, strPassword, strDomain
strUsername = Trim(Request.Form("txtUsername"))
strPassword = Trim(Request.Form("txtPassword"))
strDomain = "Intranet"
'you can easily change this to retrieve the domain from a form aswell
Set objADSI = GetObject("WinNT://" & strDomain)
     
Dim strADsNamespace
Dim objADSINamespace
strADsNamespace = Left("WinNT://" & strDomain, InStr("WinNT://" & strDomain, ":"))
Set objADSINamespace = GetObject(strADsNamespace)
Set objADSI = objADSINamespace.OpenDSObject("WinNT://" & strDomain, strDomain & "\" & strUsername, strPassword, 0)
' If there's no error then the user has been authenticated!
  
If Err.Number <> 0 Then 'authentication failed
  'code here for failed authentication
  Session("authenticated") = False
Else
  'code here for authentication success
  Session("authenticated") = True
End If
Set objADSINamespace = Nothing
Set objADSI = Nothing
Set strUsername = Nothing
Set strPassword = Nothing
Set strDomain = Nothing
Set strADsNamespace = Nothing %>
'***********************************************
At the top of all your protected ASP pages place the following:
<!-- #INCLUDE file="check.asp" -->

Make sure you check the path to the file, if necessary make it an absolute include, i.e. <!-- #INCLUDE file="http://www.yoursite.co.uk/check.asp" -->
'************************************************
create a file called check.asp, in it place the following code:
<% If Session("authenticated") <> True Then
   Session.Abandon 'clear any session variables
   Response.Redirect "login.asp" 'kick them back to the login page
End If %>