Richard Clark redspider

We have a sequence of IDs, 1, 2, 3, 4... that are references to data. We wish to use these IDs in a URL, however we do not want them to be iterable - that is, given 3, it should not be possible to derive the URL for 2 or 4.

Our proposed solution is to generate the URL as follows:

/<hmac>-<id>/

Where hmac consists of a SHA256 HMAC of the ID using a secret key. We then verify the hmac when the URL is used.

Demonstration of a partial tar extraction.

First we set up a dir for testing:

$ ls -lR
.:
total 4
drwxr-xr-x 5 richard richard 4096 2012-07-31 17:46 root_dir

	import math
	import random
	import time, os

	try:
	import RPi.GPIO as GPIO
	except ImportError:
	GPIO = None

	try:

	import random
	import time, os

	try:
	import RPi.GPIO as GPIO
	except ImportError:
	GPIO = None

	try:
	import xtermcolor

	import random
	import time, os

	try:
	import RPi.GPIO as GPIO
	except ImportError:
	GPIO = None

	try:
	import xtermcolor

	import time, os

	try:
	import RPi.GPIO as GPIO
	except ImportError:
	GPIO = None


	class Color(object):
	def __init__(self, r, g, b):

	#!/usr/bin/env python

	# Test code for Adafruit LED Pixels, uses hardware SPI

	import RPi.GPIO as GPIO, time, os

	DEBUG = 1
	GPIO.setmode(GPIO.BCM)

	import socket

	s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
	s.sendto('PING', ('127.0.0.1',540))

	data, addr = s.recvfrom(1024)
	print data, addr

	var compactListingDirective = m.directive('compactListing', function (listingService) {
	return {
	replace: true,
	scope: {
	listing: '=compactListing'
	},
	controller: function ($scope, $attrs, listingService) {
	$scope.listingService = listingService;
	},
	templateUrl: TMPL.compact_listing


	def permute(items):
	"""
	Return the permutations of the provided set

	:param items: Set of items to permute
	:type items: set
	:return: list of permutations
	:rtype: list
	"""