WindowsImpersonationContext and DirectoryServices

[Jake]

I am having a problem impersonating the current web user to run a search of
active directory to verify if the user is a member of an active directory
group. The following code works fine on my development box, but when I deploy
it to my server the code will not work. I did verify that the
“HttpContext.Current.User.Identity� picks up the correct user information so
I am a little stumped. Any help would be greatly appreciated.

Here is the code I am using:

private static StringCollection GetUserGroupsFromAd(int p_BadgeNumber)
{
StringCollection groups = new StringCollection();
WindowsImpersonationContext context = null;

try
{
WindowsIdentity ident = (WindowsIdentity)HttpContext.Current.User.Identity ;
context = WindowsIdentity.Impersonate(ident.Token);

try
{
DirectoryEntry entry = new DirectoryEntry(LDAPPATH);
DirectorySearcher search = new DirectorySearcher(entry);
search.Filter = string.Format("(&(ObjectClass=user)(employeeID={0} ))",
p_BadgeNumber.ToString());
SearchResult result = search.FindOne();

if (result != null)
{
DirectoryEntry objUser = new DirectoryEntry(result.Path);
object objGroups = objUser.Invoke("Groups");
foreach (object obj in (IEnumerable)objGroups)
{
DirectoryEntry objGrpEntry = new DirectoryEntry(obj);
groups.Add(objGrpEntry.Name);
}
}
}
catch(Exception ex)
{
// For Testing Only
HttpResponse resp = HttpContext.Current.Response;
resp.Write(ex.Message + ex.StackTrace);
}
}
finally
{
if (context != null)
context.Undo();
}
return ( groups );
}

Thanks,
Jake