Passportjs Strategies

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 480+ 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.

var app = express();
app.use(require('serve-static')(__dirname + '/../../public'));
app.use(require('cookie-parser')());
app.use(require('body-parser').urlencoded({ extended: true }));
app.use(require('express-session')({ secret: 'keyboard cat', resave: true, saveUninitialized: true }));
app.use(passport.initialize());
app.use(passport.session());

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 480 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
Azure Active Directory	OAuth 2.0 / OpenID / SAML	Azure

Examples

• For a complete, working example, refer to the example that uses passport-local.
• Local Strategy: Refer to the following tutorials for setting up user authentication via LocalStrategy (passport-local):
  • Mongo
    • Express v3x - Tutorial / working example
    • Express v4x - Tutorial / working example
  • Postgres
    • Tutorial / working example
• Social Authentication: Refer to the following tutorials for setting up various social authentication strategies:
  • Express v3x - Tutorial / working example
  • Express v4x - Tutorial / working example

Related Modules

• Locomotive — Powerful MVC web framework
• OAuthorize — OAuth service provider toolkit
• OAuth2orize — OAuth 2.0 authorization server toolkit
• connect-ensure-login — middleware to ensure login sessions

The modules page on the wiki lists other useful modules that build upon or integrate with Passport.