How can I implement OAuth authentication in a Node.js application?

How can I implement OAuth authentication in a Node.js application?

You can use libraries like Passport.js or OAuth2orize to implement OAuth in your Node.js app. Would you like a code example?

Yes, please provide a code example using Passport.js.

Sure! First, install Passport and the OAuth strategy: npm install passport passport-oauth2. Then, set it up like this:

const passport = require('passport');
const OAuth2Strategy = require('passport-oauth2');

passport.use(new OAuth2Strategy({
    authorizationURL: 'https://provider.com/oauth2/authorize',
    tokenURL: 'https://provider.com/oauth2/token',
    clientID: 'your-client-id',
    clientSecret: 'your-client-secret',
    callbackURL: 'http://localhost:3000/auth/provider/callback'
  },
  function(accessToken, refreshToken, profile, done) {
    // User authentication logic here
    return done(null, profile);
  }
));

This sets up the OAuth strategy. Do you need help with the callback route?

Yes, how do I handle the callback route?

You can handle the callback route like this:

app.get('/auth/provider/callback',
  passport.authenticate('oauth2', { failureRedirect: '/' }),
  function(req, res) {
    // Successful authentication, redirect home.
    res.redirect('/');
  });

This will redirect users after successful authentication. Let me know if you need more details!