Passport

Passport is Express-compatible authentication middleware for Node.js.

Passport's sole purpose is to authenticate requests, which it does through an extensible set of plugins known as strategies. Passport does not mount routes or assume any particular database schema, which maximizes flexiblity and allows application-level decisions to be made by the developer. The API is simple: you provide Passport a request to authenticate, and Passport provides hooks for controlling what occurs when authentication succeeds or fails.

Install

$ npm install passport

Usage

Strategies

Passport uses the concept of strategies to authenticate requests. Strategies can range from verifying username and password credentials, delegated authentication using OAuth (for example, via Facebook or Twitter), or federated authentication using OpenID.

Before authenticating requests, the strategy (or strategies) used by an application must be configured.

passport.use(new LocalStrategy(
  function(username, password, done) {
    User.findOne({ username: username }, function (err, user) {
      if (err) { return done(err); }
      if (!user) { return done(null, false); }
      if (!user.verifyPassword(password)) { return done(null, false); }
      return done(null, user);
    });
  }
));

There are 300+ strategies. Find the ones you want at: passportjs.org

Sessions

Passport will maintain persistent login sessions. In order for persistent sessions to work, the authenticated user must be serialized to the session, and deserialized when subsequent requests are made.

Passport does not impose any restrictions on how your user records are stored. Instead, you provide functions to Passport which implements the necessary serialization and deserialization logic. In a typical application, this will be as simple as serializing the user ID, and finding the user by ID when deserializing.

passport.serializeUser(function(user, done) {
  done(null, user.id);
});

passport.deserializeUser(function(id, done) {
  User.findById(id, function (err, user) {
    done(err, user);
  });
});

Middleware

To use Passport in an Express or Connect-based application, configure it with the required passport.initialize() middleware. If your application uses persistent login sessions (recommended, but not required), passport.session() middleware must also be used.

app.configure(function() {
  app.use(express.static(__dirname + '/../../public'));
  app.use(express.cookieParser());
  app.use(express.bodyParser());
  app.use(express.session({ secret: 'keyboard cat' }));
  app.use(passport.initialize());
  app.use(passport.session());
  app.use(app.router);
});

Authenticate Requests

Passport provides an authenticate() function, which is used as route middleware to authenticate requests.

app.post('/login', 
  passport.authenticate('local', { failureRedirect: '/login' }),
  function(req, res) {
    res.redirect('/');
  });

Strategies

Passport has a comprehensive set of over 300 authentication strategies covering social networking, enterprise integration, API services, and more.

Search all strategies

There is a Strategy Search at passportjs.org

The following table lists commonly used strategies:

Strategy	Protocol	Developer
Local	HTML form	Jared Hanson
OpenID	OpenID	Jared Hanson
BrowserID	BrowserID	Jared Hanson
Facebook	OAuth 2.0	Jared Hanson
Google	OpenID	Jared Hanson
Google	OAuth / OAuth 2.0	Jared Hanson
Twitter	OAuth	Jared Hanson

Examples

For a complete, working example, refer to the login example included in passport-local.
Local Strategy: Refer to the following tutorials for setting up user authentication via LocalStrategy (passport-local)
- Express v3x - Tutorial / working example
- Express v4x - Tutorial / working example
Social Authentication: Refer to this tutorial for setting up various social authentication strategies, including a working example found on this repo.