# frozen_string_literal: true require 'digest/md5' module Rack module Auth module Digest # Rack::Auth::Digest::Nonce is the default nonce generator for the # Rack::Auth::Digest::MD5 authentication handler. # # +private_key+ needs to set to a constant string. # # +time_limit+ can be optionally set to an integer (number of seconds), # to limit the validity of the generated nonces. class Nonce class << self attr_accessor :private_key, :time_limit end def self.parse(string) new(*string.unpack("m").first.split(' ', 2)) end def initialize(timestamp = Time.now, given_digest = nil) @timestamp, @given_digest = timestamp.to_i, given_digest end def to_s ["#{@timestamp} #{digest}"].pack("m").strip end def digest ::Digest::MD5.hexdigest("#{@timestamp}:#{self.class.private_key}") end def valid? digest == @given_digest end def stale? !self.class.time_limit.nil? && (Time.now.to_i - @timestamp) > self.class.time_limit end def fresh? !stale? end end end end end