# File lib/openid/filestore.rb, line 51
    def create_auth_key
      auth_key = OpenID::Util.random_string(@@AUTH_KEY_LEN)
      f, tmp = mktemp
      begin
        begin
          f.write(auth_key)
          f.fsync
        ensure
          f.close
        end
        begin
          begin
            File.link(tmp, @auth_key_name)
          rescue NotImplementedError # no link under windows
            File.rename(tmp, @auth_key_name)
          end
        rescue Errno::EEXIST
          raise if read_auth_key.nil?
        end      
      ensure
        self.remove_if_present(tmp)
      end

      auth_key
    end