# File lib/aws/core/signature/version_2.rb, line 36
        def string_to_sign

          host =
            case port
            when 80, 443 then self.host
            else "#{self.host}:#{port}"
            end

          [
            http_method,
            host.to_s.downcase,
            path,
            params.sort.collect { |p| p.encoded }.join('&'),
          ].join("\n")

        end