accounts.js

var Firebase = require("firebase");
var crypto = require("crypto");
var session = require('express-session');

var firebase = new Firebase('https://wicker-dc371.firebaseio.com/');
var users = firebase.child("users");

var MemoryStore = require('session-memory-store')(session);

function hash (password) {
  return crypto.createHash("sha512").update(password).digest("hex");
}

var router = require("express").Router();

router.use(require("body-parser").json());
router.use(require("cookie-parser")());
router.use(require("express-session")({
  resave: false,
  saveUninitialized: true,
  secret: "dsdsdagqwqgqdgdgdas;dsagadsgs",
  store: new MemoryStore({expires: 60 * 60 * 12})
}));


router.post("/api/signup", function(req, res) {
  var username = req.body.username,
      password = req.body.password;

  if (!username || !password)
    return res.json({signedIn: false, message: "no username or password"});

  users.child(username).once("value", function (snapshot) {
    if (snapshot.exists())
      return res.json({signedIn: false, message: "username already in use"});

    var userObj = {
      username: username,
      passwordHash: hash(password)
    };

    users.child(username).set(userObj);
    req.session.user= userObj;

    res.json({
      signedIn: true,
      user: userObj
    });
  })
});

router.post("/api/signin", function(req, res) {
  var username = req.body.username,
      password = req.body.password;

  if (!username || !password)
    return res.json({signedIn: false, message: "no username or password"});

  users.child(username).once("value", function (snapshot) {
    if (!snapshot.exists() && snapshot.child("passwordHash").val() !== hash(password))
      return res.json({signedIn: false, message: "wrong username or password"});

    var user = snapshot.exportVal();

    req.session.user = user;
    res.json({
      signedIn: true,
      user: user
    })
  });
});

router.post("/api/signout", function (req, res) {
  delete req.session.user;
  res.json({
    signedIn: false,
    message:"You have been signed out"
  });
});

module.exports = router;