# File lib/dnsruby/resource/RRSIG.rb, line 261
      def sig_data
        # RRSIG_RDATA is the wire format of the RRSIG RDATA fields
        # with the Signer's Name field in canonical form and
        # the Signature field excluded;
        data = MessageEncoder.new { |msg|
          msg.put_pack('ncc', @type_covered.to_i, @algorithm.to_i, @labels)
          msg.put_pack("NNN", @original_ttl, @expiration, @inception)
          msg.put_pack("n", @key_tag)
          msg.put_name(@signers_name, true)
        }.to_s
        return data
      end