percent auth middleware

This express middleware reads from a cookie named percent-auth, if it exists, it should contain something like this:

%7B%22email%22%3A%22mauricio%40lavabit.com%22%2C%22timestamp%22%3A1391522971884%2C%22signature%22%3A%227NEosnRuRTsats3HKjt4YmeHEZBFMNlu8GT5QxnUF5EjVNcgW6y2kIYYovzXYCrpHw84Aydznvhv7i3McRHDlQ%3D%3D%22%7D

If you decodeURIComponent it shows this:

{"email":"mauricio@lavabit.com","timestamp":1391522971884,"signature":"7NEosnRuRTsats3HKjt4YmeHEZBFMNlu8GT5QxnUF5EjVNcgW6y2kIYYovzXYCrpHw84Aydznvhv7i3McRHDlQ=="}

It is a signed session created by the percent servers. it contains the email of the user who logged in and a unix timestamp of when the loggin happened.

The JSON object contains a signature field which is the result of signing it with percent-message-signing using app key. The app key should be kept private as it is shared only between Percent and the app developer and used to sign and verify exchanged messages.

install:

npm install percent-auth-middleware

usage:

var express = require('express');
var percentAuth = require('percent-auth-middleware');

var percentAppKey = 'dWghkFhBB7SvGLZNI5jjHE5mh0U+73TpkKwkRYAlstc=';

var app = express()
  .use(express.cookieParser())
  .use(percentAuth({ key: percentAppKey, maxSessionSeconds: 3600 }));

app.get('/echoUser', echo);

function ensureUser(req, res, next) {
  if (! req.percent.user)
    res.send('No user logged in');
  else
    res.send('User ' + req.percent.user +
    ' logged in ' + req.percent.sessionSeconds + ' seconds ago';
}

var port = process.env.PORT || 8000;
app.listen(port, function() {
  console.log('Listening on http://localhost:%d', port);
});