express LoginDemo
cd LoginDemo
npm install

doctype html
html
 head
  meta(charset='UTF-8')
  title 登錄
  link(rel='stylesheet', href='/stylesheets/login.css')
 body
  .form-container
   p.form-header 登錄
   form(action='login', method='POST', align='center')
    table
     tr
      td
       label(for='user') 賬號(hào)：
      td
       input#user(type='text', name='login_username')
     tr
      td
       label(for='pwd') 密碼：
      td
       input#pwd(type='password', name='login_password')
     tr
      td(colspan='2', align='right')
       input(type='submit', value='登錄')
  p #{msg}

form {
 margin: 12px;
}
a {
 color: #00B7FF;
}

div.form-container {
 display: inline-block;
 border: 6px solid steelblue;
 width: 280px;
 border-radius: 10px;
 margin: 12px;
}

p.form-header {
 margin: 0px;
 font: 24px bold;
 color: white;
 background: steelblue;
 text-align: center;
}

input[type=submit]{
 font: 18px bold;
 width: 120px;
 margin-left: 12px;
}

doctype html
html
 head
  meta(charset='UTF-8')
  title= title
 body
  p #{msg}
  p #{lastTime}
  p 
   a(href='/logout') 退出

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var users = require('./routes/users');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.all('*', users.requireAuthentication);
app.use('/', users);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
 var err = new Error('Not Found');
 err.status = 404;
 next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
 app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
   message: err.message,
   error: err
  });
 });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
 res.status(err.status || 500);
 res.render('error', {
  message: err.message,
  error: {}
 });
});


module.exports = app;

var express = require('express');
var router = express.Router();
var crypto = require('crypto');

function hashPW(userName, pwd){
 var hash = crypto.createHash('md5');
 hash.update(userName + pwd);
 return hash.digest('hex');
}

// just for tutorial, it's bad really
var userdb = [
  {
   userName: "admin",
   hash: hashPW("admin", "123456"),
   last: ""
  },
  {
   userName: "foruok",
   hash: hashPW("foruok", "888888"),
   last: ""
  }
 ];

function getLastLoginTime(userName){
 for(var i = 0; i < userdb.length; ++i){
  var user = userdb[i];
  if(userName === user.userName){
   return user.last;
  }
 }
 return "";
}

function updateLastLoginTime(userName){
 for(var i = 0; i < userdb.length; ++i){
  var user = userdb[i];
  if(userName === user.userName){
   user.last = Date().toString();
   return;
  }
 }
}

function authenticate(userName, hash){

 for(var i = 0; i < userdb.length; ++i){
  var user = userdb[i];
  if(userName === user.userName){
   if(hash === user.hash){
     return 0;
   }else{
     return 1;
   }
  }
 }

 return 2;
}

function isLogined(req){
 if(req.cookies["account"] != null){
  var account = req.cookies["account"];
  var user = account.account;
  var hash = account.hash;
  if(authenticate(user, hash)==0){
   console.log(req.cookies.account.account + " had logined.");
   return true;
  }
 }
 return false;
};

router.requireAuthentication = function(req, res, next){
 if(req.path == "/login"){
  next();
  return;
 }

 if(req.cookies["account"] != null){
  var account = req.cookies["account"];
  var user = account.account;
  var hash = account.hash;
  if(authenticate(user, hash)==0){
   console.log(req.cookies.account.account + " had logined.");
   next();
   return;
  }
 }
 console.log("not login, redirect to /login");
 res.redirect('/login?'+Date.now());
};

router.post('/login', function(req, res, next){
 var userName = req.body.login_username;
 var hash = hashPW(userName, req.body.login_password);
 console.log("login_username - " + userName + " password - " + req.body.login_password + " hash - " + hash);
 switch(authenticate(userName, hash)){
 case 0: //success
  var lastTime = getLastLoginTime(userName);
  updateLastLoginTime(userName);
  console.log("login ok, last - " + lastTime);
  res.cookie("account", {account: userName, hash: hash, last: lastTime}, {maxAge: 60000});
  res.redirect('/profile?'+Date.now());
  console.log("after redirect");
  break;
 case 1: //password error
  console.log("password error");
  res.render('login', {msg:"密碼錯(cuò)誤"});
  break;
 case 2: //user not found
  console.log("user not found");
  res.render('login', {msg:"用戶(hù)名不存在"});
  break;
 }
});

router.get('/login', function(req, res, next){
 console.log("cookies:");
 console.log(req.cookies);
 if(isLogined(req)){
  res.redirect('/profile?'+Date.now());
 }else{
  res.render('login');
 }
});

router.get('/logout', function(req, res, next){
 res.clearCookie("account");
 res.redirect('/login?'+Date.now());
});

router.get('/profile', function(req, res, next){
 res.render('profile',{
  msg:"您登錄為："+req.cookies["account"].account, 
  title:"登錄成功",
  lastTime:"上次登錄："+req.cookies["account"].last
 });
});

module.exports = router;

//加載body-parser模塊
var bodyParser = require('body-parser');
...
//應(yīng)用中間件
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

var userName = req.body.login_username;

var cookieParser = require('cookie-parser');
...
app.use(cookieParser());

res.cookie(name, value [, options])