ama-team / cookbook-ssh-private-keys

require 'tempfile'

require 'English'

require_relative 'generator'

require_relative 'exception/invalid_key_exception'

module AMA

  module Chef

    module SSHPrivateKeys

      # Simple utility for validating provided key pair

      class Validator

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

        def validate!(key_pair)

          generated_public_key = generator.generate_public_key(

            key_pair.compute_private_key,

            key_pair.comment

          )

          if key_pair.type && key_pair.type != generated_public_key.type

            message = "Key was provided with type #{key_pair.type}, but " \

              "#{generated_public_key.type} was discovered"

            raise_invalid_key_exception(message)

          end

          public_key = key_pair.public_key

          return unless public_key && public_key != generated_public_key.content

          message = 'Generated public key differs from provided public key'

          raise_invalid_key_exception(message)

        end

        private

        def generator

          return @generator if @generator

          @generator = Generator.new(Generator.locate_binary!)

        end

        # @param [String] message

        def raise_invalid_key_exception(message)

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

          raise klass, message