Class: Ddig::Ddr

Inherits:
Object
  • Object
show all
Defined in:
lib/ddig/ddr.rb,
lib/ddig/ddr/verify_cert.rb,
lib/ddig/ddr/designated_resolver.rb

Overview

DDR client (Discovery of Designated Resolvers)

Defined Under Namespace

Classes: DesignatedResolver, VerifyCert

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(nameservers: nil, ip: nil) ⇒ Ddr

Returns a new instance of Ddr.



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# File 'lib/ddig/ddr.rb', line 13

def initialize(nameservers: nil, ip: nil)
  @ip = ip

  @nameserver = Ddig::Nameserver.new(nameservers: nameservers)
  set_nameservers

  # discover designated resolvers
  query_svcb_records
  discover_designated_resolvers
  verify_discovery
end

Instance Attribute Details

#designated_resolvers ⇒ Object (readonly)

Returns the value of attribute designated_resolvers.



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# File 'lib/ddig/ddr.rb', line 11

def designated_resolvers
  @designated_resolvers
end

#ip ⇒ Object (readonly)

Returns the value of attribute ip.



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# File 'lib/ddig/ddr.rb', line 10

def ip
  @ip
end

#nameservers ⇒ Object (readonly)

Returns the value of attribute nameservers.



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# File 'lib/ddig/ddr.rb', line 10

def nameservers
  @nameservers
end

#svcb_records ⇒ Object (readonly)

Returns the value of attribute svcb_records.



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# File 'lib/ddig/ddr.rb', line 11

def svcb_records
  @svcb_records
end

Instance Method Details

#as_json ⇒ Object 



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# File 'lib/ddig/ddr.rb', line 133

def as_json(*)
  {
    designated_resolvers: @designated_resolvers.map { |designated_resolver| designated_resolver.as_json },
    hostname: @hostname,
    nameservers: @nameservers,
    ip: @ip,
  }
end

#discover_designated_resolvers ⇒ Object

Discovery Designated Resolvers from SVCB RR Set ref. www.rfc-editor.org/rfc/rfc9461.html



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# File 'lib/ddig/ddr.rb', line 47

def discover_designated_resolvers
  @designated_resolvers = []

  @svcb_records.each do |item|
    unencrypted_resolver = item[:unencrypted_resolver]
    svcb_record = item[:svcb_record]

    target = svcb_record.target.to_s
    priority = svcb_record.priority
    protocols = svcb_record.params[:alpn].protocol_ids
    port = svcb_record.params[:port]&.port
    dohpath = svcb_record.params[:dohpath]&.template
    ipv4hint = svcb_record.params[:ipv4hint]&.addresses
    ipv6hint = svcb_record.params[:ipv6hint]&.addresses

    # Skip AliasMode of SVCB RR
    if priority.zero?
      next
    end

    protocols.each do |protocol|
      do53_v4 = ::Ddig::Resolver::Do53.new(hostname: target, nameservers: [unencrypted_resolver], ip: :ipv4).lookup
      do53_v6 = ::Ddig::Resolver::Do53.new(hostname: target, nameservers: [unencrypted_resolver], ip: :ipv6).lookup

      # ipv4
      unless @ip == :ipv6
        unless do53_v4.nil? || do53_v4.a.nil?
          do53_v4.a.each do |address|
            designated_resolver = ::Ddig::Ddr::DesignatedResolver.new(unencrypted_resolver: unencrypted_resolver, target: target, protocol: protocol, port: port, dohpath: dohpath, address: address.to_s, ip: :ipv4)
            @designated_resolvers << designated_resolver
          end
        end
        unless do53_v6.nil? || do53_v6.a.nil?
          do53_v6.a.each do |address|
            designated_resolver = ::Ddig::Ddr::DesignatedResolver.new(unencrypted_resolver: unencrypted_resolver, target: target, protocol: protocol, port: port, dohpath: dohpath, address: address.to_s, ip: :ipv4)
            @designated_resolvers << designated_resolver
          end
        end
      end

      # ipv6
      unless @ip == :ipv4
        unless do53_v4.nil? || do53_v4.aaaa.nil?
          do53_v4.aaaa.each do |address|
            designated_resolver = ::Ddig::Ddr::DesignatedResolver.new(unencrypted_resolver: unencrypted_resolver, target: target, protocol: protocol, port: port, dohpath: dohpath, address: address.to_s, ip: :ipv6)
            @designated_resolvers << designated_resolver
          end
        end
        unless do53_v6.nil? || do53_v6.aaaa.nil?
          do53_v6.aaaa.each do |address|
            designated_resolver = ::Ddig::Ddr::DesignatedResolver.new(unencrypted_resolver: unencrypted_resolver, target: target, protocol: protocol, port: port, dohpath: dohpath, address: address.to_s, ip: :ipv6)
            @designated_resolvers << designated_resolver
          end
        end
      end

      # ipv4hint
      unless ipv4hint.nil? || @ip == :ipv6
        ipv4hint.each do |address|
          ip = :ipv4
          designated_resolver = ::Ddig::Ddr::DesignatedResolver.new(unencrypted_resolver: unencrypted_resolver, target: target, protocol: protocol, port: port, dohpath: dohpath, address: address.to_s, ip: ip)
          @designated_resolvers << designated_resolver
        end
      end

      # ipv6hint
      unless ipv6hint.nil? || @ip == :ipv4
        ipv6hint.each do |address|
          ip = :ipv6
          designated_resolver = ::Ddig::Ddr::DesignatedResolver.new(unencrypted_resolver: unencrypted_resolver, target: target, protocol: protocol, port: port, dohpath: dohpath, address: address.to_s, ip: ip)
          @designated_resolvers << designated_resolver
        end
      end
    end
  end

  @designated_resolvers.uniq! { |designated_resolver| designated_resolver.uniq_key }
end

#query_svcb_records ⇒ Object 



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# File 'lib/ddig/ddr.rb', line 25

def query_svcb_records
  @svcb_records = []

  if @nameservers.empty?
    return @svcb_records
  end

  @nameservers.each do |nameserver|
    svcb_rrset = Resolv::DNS.open(nameserver: nameserver) do |dns|
      dns.getresources('_dns.resolver.arpa', Resolv::DNS::Resource::IN::SVCB)
    end

    svcb_rrset.sort_by!(&:priority)

    @svcb_records += svcb_rrset.map { |svcb_record| { unencrypted_resolver: nameserver, svcb_record: svcb_record } }
  end

  @svcb_records
end

#set_nameservers ⇒ Object 



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# File 'lib/ddig/ddr.rb', line 155

def set_nameservers
  @nameservers = @nameserver.servers

  if @ip == :ipv4
    @nameservers = @nameserver.servers_ipv4
  end

  if @ip == :ipv6
    @nameservers = @nameserver.servers_ipv6
  end
end

#to_cli ⇒ Object 



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# File 'lib/ddig/ddr.rb', line 146

def to_cli
  @designated_resolvers.each do |designated_resolver|
    puts designated_resolver.to_s
  end

  puts
  puts "# SERVER: #{@nameservers.join(', ')}"
end

#to_json(*args) ⇒ Object 



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# File 'lib/ddig/ddr.rb', line 142

def to_json(*args)
  as_json.to_json
end

#verify_discovery ⇒ Object 



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# File 'lib/ddig/ddr.rb', line 126

def verify_discovery
  @designated_resolvers.map! do |designated_resolver|
    designated_resolver.verify
    designated_resolver
  end
end