feathers-authentication-jwt

JWT authentication strategy for feathers-authentication using Passport

Installation

npm install feathers-authentication-jwt --save

Documentation

API

This module contains 3 core pieces:

The main entry function
The Verifier class
The ExtractJwt object from passport-jwt.

Main Initialization

In most cases initializing the feathers-authentication-jwt module is as simple as doing this:

app.configure(authentication(settings));
app.configure(jwt());

This will pull from your global auth object in your config file. It will also mix in the following defaults, which can be customized.

Default Options

{
    name: 'jwt', // the name to use when invoking the authentication Strategy
    entity: 'user', // the entity that you pull from if an 'id' is present in the payload
    service: 'users', // the service to look up the entity
    passReqToCallback: true, // whether the request object should be passed to `verify`
    jwtFromRequest: ExtractJwt.fromHeader, // a passport-jwt option determining where to parse the JWT
    secretOrKey: auth.secret, // Your main secret provided to passport-jwt
    session: false // whether to use sessions,
    Verifier: Verifier // A Verifier class. Defaults to the built-in one but can be a custom one. See below for details.
}

Additional passport-jwt options can be provided.

Verifier

This is the verification class that receives the JWT payload (if verification is successful) and either returns the payload or, if an id is present in the payload, populates the entity (normally a user) and returns both the entity and the payload. It has the following methods that can all be overridden. The verify function has the exact same signature as passport-jwt.

{
    constructor(app, options) // the class constructor
    verify(req, payload, done) // queries the configured service
}

Customizing the Verifier

The Verifier class can be extended so that you customize it's behavior without having to rewrite and test a totally custom local Passport implementation. Although that is always an option if you don't want use this plugin.

An example of customizing the Verifier:

import jwt, { Verifier } from 'feathers-authentication-jwt';

class CustomVerifier extends Verifier {
  // The verify function has the exact same inputs and 
  // return values as a vanilla passport strategy
  verify(req, payload, done) {
    // do your custom stuff. You can call internal Verifier methods
    // and reference this.app and this.options. This method must be implemented.
    done(null, payload);
  }
}

app.configure(jwt({ Verifier: CustomVerifier }));

ExtractJwt

This is a collection of functions provided by passport-jwt that allow you to parse the JWT from anywhere. By default the header field from when you initialize feathers-authentication is used. However you can customize to pull from whatever you like.

// Example of pulling from the body instead
import jwt, { ExtractJwt } from 'feathers-authentication-jwt';

app.configure(jwt({ jwtFromRequest: ExtractJwt.fromBodyField('accessToken') }));

Expected Request Data

By default, this strategy expects a payload in this format:

{
  strategy: 'jwt',
  accessToken: '<token>'
}

Complete Example

Here's a basic example of a Feathers server that uses feathers-authentication-jwt. You can see a fully working example in the example/ directory.

const feathers = require('feathers');
const rest = require('feathers-rest');
const hooks = require('feathers-hooks');
const memory = require('feathers-memory');
const bodyParser = require('body-parser');
const errorHandler = require('feathers-errors/handler');
const auth = require('feathers-authentication');
const jwt = require('feathers-authentication-jwt');

// Initialize the application
const app = feathers()
  .configure(rest())
  .configure(hooks())
  // Needed for parsing bodies (login)
  .use(bodyParser.json())
  .use(bodyParser.urlencoded({ extended: true }))
  // Configure feathers-authentication
  .configure(auth({ secret: 'super secret' }))
  .configure(jwt())
  .use('/users', memory())
  .use(errorHandler());

app.listen(3030);

console.log('Feathers app started on 127.0.0.1:3030');

License

Licensed under the MIT license.

Package detail