docs: def getCert(username, password,
              certHost=_SERVER,
              certfile=None,
              certQuery=_PROXY):
      """Access the cadc certificate server."""
  
      if certfile is None:
          certfile = tempfile.NamedTemporaryFile()
  
      # Add the username and password.
      # If we knew the realm, we could use it instead of ``None``.
      password_mgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
      top_level_url = "http://" + certHost
      logging.debug(top_level_url)
      password_mgr.add_password(None, top_level_url, username, password)
      handler = urllib2.HTTPBasicAuthHandler(password_mgr)
      logging.debug(str(handler))
      # create "opener" (OpenerDirector instance)
      opener = urllib2.build_opener(handler)
  
      # Install the opener.   
      urllib2.install_opener(opener)
  
      # buuld the url that with 'GET' a certificat using user_id/password info
      url = "http://" + certHost + certQuery
      logging.debug(url)
  
      r = None
      try:
          r = opener.open(url)
      except urllib2.HTTPError as e:
          logging.debug(url)
          logging.debug(str(e))
          return False
  
      logging.debug(str(r))
  
      if r is not None:
          while True:
              buf = r.read()
              logging.debug(buf)
              if not buf:
                  break
              certfile.write(buf)
          r.close()
  
      return certfile