# ex:ts=4
#
# chasc
#   -- Challenge Handshaking Authentication on Stateless Connections
#
# $LinuxKorea: chasc.py,v 1.2 2001/09/17 09:22:42 perky Exp $
#
# Copyright 2001 Hye-Shik Chang. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without 
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. Neither the name of author nor the names of its contributors
#    may be used to endorse or promote products derived from this software
#    without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE. 
#
# code by Hye-Shik Chang <perky@linuxkorea.co.kr>
#

import time, md5

class CHASC:
	""" Challenge Handshaking Authentication on Stateless Connections """

	def __init__(self):
		self.chal = {} # chanllenger: userid
		self.sess = {} # session id : userid
	
	def contact(userid):
		""" contact(userid) : first contact for user. returns challenge salt """
		pass
	
	def challenge(challenger):
		""" challenge(challenger) : second crypted result for challenging. returns session id """
		pass
	
	def clear():
		""" clear() : clear timeouted contacts """
		pass
	
	def logout(sessionid):
		""" logout(sessionid) : log out """
		pass