# File lib/Dnsruby/SingleResolver.rb, line 406
    def check_tsig(query, response, response_bytes)
      if (query.tsig)
        if (response.tsig)
          if !query.tsig.verify(query, response, response_bytes)
            # Discard packet and wait for correctly signed response
            TheLog.error("TSIG authentication failed!")
            return false
          end
        else
          # Treated as having format error and discarded (RFC2845, 4.6)
          TheLog.error("Expecting TSIG signed response, but got unsigned response - discarding")
          return false
        end
      elsif (response.tsig)
        # Error - signed response to unsigned query
        TheLog.error("Signed response to unsigned query")
        return false
      end      
      return true
    end