vendor/rails/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/digest/nonce.rb

   1 require 'digest/md5'
   2
   3 module Rack
   4   module Auth
   5     module Digest
   6       # Rack::Auth::Digest::Nonce is the default nonce generator for the
   7       # Rack::Auth::Digest::MD5 authentication handler.
   8       #
   9       # +private_key+ needs to set to a constant string.
  10       #
  11       # +time_limit+ can be optionally set to an integer (number of seconds),
  12       # to limit the validity of the generated nonces.
  13
  14       class Nonce
  15
  16         class << self
  17           attr_accessor :private_key, :time_limit
  18         end
  19
  20         def self.parse(string)
  21           new(*string.unpack("m*").first.split(' ', 2))
  22         end
  23
  24         def initialize(timestamp = Time.now, given_digest = nil)
  25           @timestamp, @given_digest = timestamp.to_i, given_digest
  26         end
  27
  28         def to_s
  29           [([ @timestamp, digest ] * ' ')].pack("m*").strip
  30         end
  31
  32         def digest
  33           ::Digest::MD5.hexdigest([ @timestamp, self.class.private_key ] * ':')
  34         end
  35
  36         def valid?
  37           digest == @given_digest
  38         end
  39
  40         def stale?
  41           !self.class.time_limit.nil? && (@timestamp - Time.now.to_i) < self.class.time_limit
  42         end
  43
  44         def fresh?
  45           !stale?
  46         end
  47
  48       end
  49     end
  50   end
  51 end