# coding: utf-8
# frozen_string_literal: true

# This file is part of IPsec packetgen plugin.
# See https://github.com/sdaubert/packetgen-plugin-ipsec for more informations
# Copyright (c) 2018 Sylvain Daubert <sylvain.daubert@laposte.net>
# This program is published under MIT license.

module PacketGen::Plugin
  class IKE
    # This class handles Certificate Request payloads.
    #
    # A CertReq payload consists of the IKE generic payload Plugin (see {Payload})
    # and some specific fields:
    #                        1                   2                   3
    #    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    #   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    #   | Next Payload  |C|  RESERVED   |         Payload Length        |
    #   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    #   | Cert Encoding |                                               |
    #   +-+-+-+-+-+-+-+-+                                               +
    #   |                                                               |
    #   ~                      Certification Authority                  ~
    #   |                                                               |
    #   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    # These specific fields are:
    # * {#encoding},
    # * and {#content} (Certification Authority).
    #
    # == Create a CertReq payload
    #   # Create a IKE packet with a CertReq payload
    #   pkt = PacketGen.gen('IP').add('UDP').add('IKE').add('IKE::CertReq', encoding: 'X509_CERT_SIG')
    #   pkt.ike_certreq.content.read OpenSSL::Digest::SHA1.digest(ca_cert.to_der)
    #   pkt.calc_length
    # @author Sylvain Daubert
    class CertReq < Cert
      # Payload type number
      PAYLOAD_TYPE = 38

      # Get list of 20-byte string (SHA-1 hashes)
      # @return [String]
      def human_content
        strs = []
        idx = 0
        while idx < content.size
          strs << content[idx, 20]
          idx += 20
        end
        strs.map(&:inspect).join(',')
      end

      # @return [String]
      def inspect
        super do |attr|
          next unless attr == :content

          str = PacketGen::Inspect.shift_level
          str << PacketGen::Inspect::FMT_ATTR % ['hashes', :content, human_content]
        end
      end
    end
  end

  PacketGen::Header.add_class IKE::CertReq
end