gistfile1.coffee

Cookie	= require('connect').middleware.session.Cookie
crypto	= require 'crypto'

module.exports = (opts) -> (req, res, next) ->
	cookie = new Cookie
	sign = (data) ->
		hmac = crypto.createHmac 'sha1', opts.secret
		hmac.update data
		hmac.digest 'hex'
	decode = ->
		[data, signature] = req.cookies[opts.key].split '--'
		return {} unless signature is sign data
		try
			JSON.parse do new Buffer(data, 'base64').toString
		catch e
			{}
	encode = ->
		json = JSON.stringify req.session
		base64 = new Buffer(json).toString 'base64'
		"#{base64}--#{sign base64}"
	writeHead = res.writeHead
	res.writeHead = (status, headers) ->
		res.setHeader 'Set-Cookie', cookie.serialize opts.key, do encode
		res.writeHead = writeHead
		res.writeHead status, headers
	req.session = do decode
	do next