ama-team / cookbook-ssh-private-keys

      class Validator

        def initialize

          @handler = nil

        end

        # @param [AMA::Chef::SSHPrivateKeys::Model::KeyPair] pair

        def validate!(pair)

          unless pair.private_key

            message = "Provided key pair #{pair.id} is missing private key"

            raise_invalid_key_exception(message)

          end

          public_key = handler.generate_public_key(pair)

          unless pair.type == public_key.type

            message = "Key pair specified type #{pair.type}, but " \

              "#{public_key.type} was discovered"

            raise_invalid_key_exception(message)

          end

          return unless pair.public_key && pair.public_key != public_key.data

          message = [

            'Generated public key differs from ' \

              "provided public key `#{pair.id}`",

            "Provided: #{pair.public_key}",

            "Generated: #{public_key.data}"

          ]

          raise_invalid_key_exception(message.join(" #{$ORS}"))

        end

        private

        def handler

          return @handler if @handler

          binary = SSHKeygenHandler.locate_binary!

          @handler = SSHKeygenHandler.new(binary)

        end

        # @param [String] message

        def raise_invalid_key_exception(message)

          klass = AMA::Chef::SSHPrivateKeys::Exception::InvalidKeyException

          raise klass, message

        end

      end