var salt = 'secret key'
function mk_hash(s) {
return crypto.createHash('sha1').update(s).digest('hex')
}
function mk_cookie(c) {
return c.toString() + '-' + mk_hash(c.toString() + salt)
}
function gt_cookie(s) {
var splits = s.split("-", 2);
var counter = parseInt(splits[0])
var hash = splits[1]
if (mk_hash(counter.toString() + salt) == hash) {
return counter
} else { return 0 }
}
app.get('/', function(req, res){ .... });