How can I use Passport.js with JWT for authentication?

How can I use Passport.js with JWT for authentication?

You can use Passport.js with JWT by setting up a strategy for JWT authentication. First, install the necessary packages: passport, passport-jwt, and jsonwebtoken. Then, configure the JWT strategy to extract the token from the request headers.

What does the configuration look like?

Here's a basic configuration:

const JwtStrategy = require('passport-jwt').Strategy;
const ExtractJwt = require('passport-jwt').ExtractJwt;

const opts = {
  jwtFromRequest: ExtractJwt.fromAuthHeaderAsBearerToken(),
  secretOrKey: 'your_jwt_secret',
};

passport.use(new JwtStrategy(opts, (jwt_payload, done) => {
  User.findById(jwt_payload.id)
    .then(user => {
      if (user) {
        return done(null, user);
      }
      return done(null, false);
    })
    .catch(err => done(err, false));
}));

How do I generate a JWT token after user login?

After validating the user's credentials, you can generate a JWT token like this:

const jwt = require('jsonwebtoken');

const token = jwt.sign({ id: user.id }, 'your_jwt_secret', { expiresIn: '1h' });
return res.json({ token });

Can I set different expiration times for different users?

Yes, you can set different expiration times by passing the expiresIn option dynamically based on user roles or preferences when generating the token.