Active Directory sin password??

[Peterpay]

public bool UserExists(string username)
{
DirectoryEntry de = GetDirectoryEntry();
DirectorySearcher deSearch = new DirectorySearcher();

deSearch.SearchRoot = de;
deSearch.Filter = "(&(objectClass=user) (cn=" + username + "))";

SearchResultCollection results = deSearch.FindAll();

return results.Count > 0;
}


con est o puedes saber si pertenece el username al directorio activo