passport-facebook
Passport strategy for authenticating with Facebook
using OAuth 2.0.
This module lets you authenticate using Facebook in your Node.js applications.
By plugging into Passport, Facebook Login can be easily and unobtrusively
integrated into any application or framework that supports
Connect-style middleware,
including Express.
:seedling: Tutorial •
:brain: Understanding OAuth 2.0 •
:heart: Sponsors
Developed by Jared Hanson.
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Install
$ npm install passport-facebook
Usage
Register Application
The Facebook strategy authenticates users using their Facebook account. Before
your application can make use of Facebook's authentication system, you must
first register
your app. Once registered, an app ID and secret will be issued which are used
by Facebook to identify your app. You will also need to configure a redirect
URI which matches the route in your application.
Configure Strategy
Once you've registered your application, the strategy
needs to be configured with your application's app ID and secret, along with
its OAuth 2.0 redirect endpoint.
The strategy takes a verify function as an argument, which accepts
accessToken, refreshToken, and profile as arguments. accessToken and
refreshToken are used for API access, and are not needed for authentication.
profile contains the user's profile information
stored in their Facebook account. When authenticating a user, this strategy
uses the OAuth 2.0 protocol to obtain this information via a sequence of
redirects and API requests to Facebook.
The verify function is responsible for determining the user to which the
Facebook account belongs. In cases where the account is logging in for the
first time, a new user record is typically created automatically. On subsequent
logins, the existing user record will be found via its relation to the Facebook
account.
Because the verify function is supplied by the application, the app is free to
use any database of its choosing. The example below illustrates usage of a SQL
database.
var FacebookStrategy = require('passport-facebook');
passport.use(new FacebookStrategy({
clientID: process.env['FACEBOOK_APP_ID'],
clientSecret: process.env['FACEBOOK_APP_SECRET'],
callbackURL: 'https://www.example.com/oauth2/redirect/facebook',
state: true
},
function verify(accessToken, refreshToken, profile, cb) {
db.get('SELECT * FROM federated_credentials WHERE provider = ? AND subject = ?', [
'https://www.facebook.com',
profile.id
], function(err, cred) {
if (err) { return cb(err); }
if (!cred) {
// The account at Facebook has not logged in to this app before. Create
// a new user record and associate it with the Facebook account.
db.run('INSERT INTO users (name) VALUES (?)', [
profile.displayName
], function(err) {
if (err) { return cb(err); }
var id = this.lastID;
db.run('INSERT INTO federated_credentials (user_id, provider, subject) VALUES (?, ?, ?)', [
id,
'https://www.facebook.com',
profile.id
], function(err) {
if (err) { return cb(err); }
var user = {
id: id,
name: profile.displayName
};
return cb(null, user);
});
});
} else {
// The account at Facebook has previously logged in to the app. Get the
// user record associated with the Facebook account and log the user in.
db.get('SELECT * FROM users WHERE id = ?', [ cred.user_id ], function(err, user) {
if (err) { return cb(err); }
if (!user) { return cb(null, false); }
return cb(null, user);
});
}
});
}
));
Define Routes
Two routes are needed in order to allow users to log in with their Facebook
account. The first route redirects the user to the Facebook, where they will
authenticate:
app.get('/login/facebook', passport.authenticate('facebook'));
The second route processes the authentication response and logs the user in,
after Facebook redirects the user back to the app:
app.get('/oauth2/redirect/facebook',
passport.authenticate('facebook', { failureRedirect: '/login', failureMessage: true }),
function(req, res) {
res.redirect('/');
});
Examples
-
todos-express-facebook
Illustrates how to use the Facebook strategy within an Express application. For
developers new to Passport and getting started, a tutorial
is available.
-
todos-express-facebook-popup
Illustrates how to use progressive enhancement to display the the Facebook
login dialog in a popup window. State is kept during the OAuth 2.0 flow and
used to close the window for requests using that display mode.
FAQ
How do I ask a user for additional permissions?
If you need additional permissions from the user, the permissions can be
requested via the scope option to passport.authenticate().
app.get('/auth/facebook',
passport.authenticate('facebook', { scope: ['user_friends', 'manage_pages'] }));
Refer to permissions with Facebook Login
for further details.
How do I re-ask for for declined permissions?
Set the authType option to reauthenticate when authenticating.
app.get('/auth/facebook',
passport.authenticate('facebook', { authType: 'reauthenticate', scope: ['user_friends', 'manage_pages'] }));
Refer to re-asking for declined permissions
for further details.
How do I obtain a user profile with specific fields?
The Facebook profile contains a lot of information about a user. By default,
not all the fields in a profile are returned. The fields needed by an application
can be indicated by setting the profileFields option.
new FacebookStrategy({
clientID: FACEBOOK_APP_ID,
clientSecret: FACEBOOK_APP_SECRET,
callbackURL: "http://localhost:3000/auth/facebook/callback",
profileFields: ['id', 'displayName', 'photos', 'email']
}), ...)
Refer to the User
section of the Graph API Reference for the complete set of available fields.
How do I include app secret proof in API requests?
Set the enableProof option when creating the strategy.
new FacebookStrategy({
clientID: FACEBOOK_APP_ID,
clientSecret: FACEBOOK_APP_SECRET,
callbackURL: "http://localhost:3000/auth/facebook/callback",
enableProof: true
}, ...)
As detailed in securing graph API requests,
requiring the app secret for server API requests helps prevent use of tokens
stolen by malicous software or man in the middle attacks.
Why is #_=_ appended to the redirect URI?
This behavior is "by design" according to Facebook's response to a bug
filed regarding this issue.
Fragment identifiers are not supplied in requests made to a server, and as such
this strategy is not aware that this behavior is exhibited and is not affected
by it. If desired, this fragment can be removed on the client side. Refer to
this discussion on
Stack Overflow for recommendations on how to accomplish such removal.
Authors
License
The MIT License
Copyright (c) 2011-2023 Jared Hanson
}