NodeJS User Registration and Authentication

index.js

//index.js
var express = require('express'),
    app = module.exports = express.createServer(),
    mongoose = require('mongoose');

mongoose.connect('mongodb://localhost/nodeAuth');

//configure app
app.configure(function() {
  app.set('views', __dirname + '/views');
  app.set('view_options', {layout : false});
  app.use(express.bodyParser());
  app.use(express.methodOverride());
  app.use(app.router);
  app.use("/assets", express.static(__dirname + '/assets'));
  app.use('/models', __dirname + '/models');
});

//include the maps controller
var users = require('./controllers/users_controller.js');
//app.<REQUEST_METHOD>(<REQUEST_URI>, <CONTROLLER_METHOD>)
app.get('/users/create', users.create);
app.post('/users/create', users.create);
app.get('/users/login', users.login);
app.post('/users/login', users.login);

app.listen(3385);

login.jade

//login.jade

!!! 5
html
  head
   title Login

  body

    h1 Login

    form(name = "login", action = "/users/login", method = "post")
      | Email
      input(type="text", name="email", id="email")
      br
      | Password
      input(type="text", name="password", id="password")
      br
      input(type="submit", value="Login")

signup.jade

//signup.jade

!!! 5
html
  head
   title Sign Up

  body

    h1 Sign Up

    form(name = "find", action = "/users/create", method = "post")
      | Firstname
      input(type="text", name="firstname", id="firstname")
      br
      | Lastname
      input(type="text", name="lastname", id="lastname")
      br
      | Email
      input(type="text", name="email", id="email")
      br
      | Password
      input(type="password", name="password", id="password")
      br
      | Repeat Password
      input(type="password", name="repeat_password", id="repeat_password")
      br
      input(type="submit", value="Search")

users_controller.js

//users_controller.js

var crypto = require("crypto");
var user = require("../models/users_model.js");
var UserModel = new user();

exports.create = function(req, res) {

  if(req.method.toLowerCase() != "post") {
    res.render("signup.jade", {layout: false});
  }
  else {
     new user(req.body).save();
     res.send("ok");
  }

}

exports.login = function(req, res) {

  if(req.method.toLowerCase() != "post") {
    res.render("login.jade", {layout: false});
  }
  else {
    user.findOne({email: req.body.email}, function(err, result) {
       if(err) console.log(err);

         if(result == null) {
           res.send('invalid username', 
		    {'Content-type' : 'text/plain'}, 
                    403);
         }
	 else {
           auth(result);
         }
    });

    function auth( userRes ) {
      if(!UserModel.encrypt(req.body.password) == userRes.password) {
         res.send('invalid password', 
		  {'Content-type' : 'text/plain'}, 
                  403);
      } else {
         console.log(userRes._id);
         user.update({_id : userRes._id}, {'$set' : {token : Date.now}});
         res.send(userRes);
      }
    }
  }
}

users_model.js

//user_model.js

var mongoose = require('mongoose'),
    Schema = mongoose.Schema,
    ObjectId = Schema.ObjectId,
    crypto = require('crypto'),
    require('assert');

var algorithm = 'aes256'; 
var key = 'D#$DF#QD#@~!W@E@';
var pw = '';

//USER SCHEMA
var userSchema = new Schema({
			ObjectId: ObjectId,
                        date: {type: Date, default: Date.now},
                        firstname: {type: String},
                        lastname: {type: String},
			email: {type: String, unique: true},
                        password: String
                        
});

//encrypt method
userSchema.methods.encrypt = function encrypt(str) {
  pw = str;
  var cipher = crypto.createCipher(algorithm, key);  
  var encrypted = cipher.update(pw, 'utf8', 'hex') + cipher.final('hex');
  console.log("ENCRYPTED: " + encrypted);
  return encrypted;
}

//password setter
userSchema.path('password').set(function(v) {
  return this.encrypt(v);
});

module.exports = mongoose.model('User', userSchema);

j'ai implementer un code semblabe mais j'ai une erreur qui persiste toujours celle-ci:
Cannot read property 'lastName' of undefined. cela c'est quand je mais les attributs de ma collection et quand je fait comme ceci ''var user= new User (req.body)'' sa enregistre sans mettre les donnees de user dans la bd. pardon besoin d'aide merci