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
|