@pokusew/express-jwt

express-jwt

Middleware that validates JSON Web Tokens and sets req.user.

This module lets you authenticate HTTP requests using JWT tokens in your Node.js applications. JWTs are typically used to protect API endpoints, and are often issued using OpenID Connect.

It's forked, whats different?

This module if forked form express-jwt made by @auth0. Followings points where changed:

• removed dependency on node-jsonwebtoken
• rewritten to ES2016 using babel transpiler
• now you can pass your own decode and verify functions for token decoding and verifying (see examples)

TODO

• update all examples according to the changes

Installing

npm install @pokusew/express-jwt --save --production

Usage

The JWT authentication middleware authenticates callers using a JWT. If the token is valid, req.user will be set with the JSON object decoded to be used by later middleware for authorization and access control.

Note, that you must include verify and decode functions. You can use node-jsonwebtoken.

For example,

import jwt from 'jsonwebtoken';
import expressJwt from '@pokusew/express-jwt';

const protectMiddleware = expressJwt({
	decode: jwt.decode,
	verify: jwt.verify,
	secret: 'shhhhhhared-secret',
});

app.get('/protected', protectMiddleware, function (req, res) {

		if (!req.user.admin) {
			return res.sendStatus(401);
		}

		res.sendStatus(200);
	}
);

You can specify another options that will be passed to verify function. So if you are using node-jsonwebtoken as this example, you can specify audience and/or issuer as well:

const protectMiddleware = expressJwt({ decode: jwt.decode, verify: jwt.verify, secret: 'shhhhhhared-secret', audience: 'http://myapi/protected', issuer: 'http://issuer' });

Optionally you can make some paths unprotected as follows:

```javascript
app.use(jwt({ secret: 'shhhhhhared-secret'}).unless({path: ['/token']}));

This is especially useful when applying to multiple routes. In the example above, path can be a string, a regexp, or an array of any of those.

For more details on the .unless syntax including additional options, please see express-unless.

By default, the decoded token is attached to req.user but can be configured with the requestProperty option.

A custom function for extracting the token from a request can be specified with the getToken option. This is useful if you need to pass the token through a query parameter or a cookie. You can throw an error in this function and it will be handled by express-jwt.

app.use(jwt({
  secret: 'hello world !',
  credentialsRequired: false,
  getToken: function fromHeaderOrQuerystring (req) {
    if (req.headers.authorization && req.headers.authorization.split(' ')[0] === 'Bearer') {
        return req.headers.authorization.split(' ')[1];
    } else if (req.query && req.query.token) {
      return req.query.token;
    }
    return null;
  }
}));

Multi-tenancy

If you are developing an application in which the secret used to sign tokens is not static, you can provide a callback function as the secret parameter. The function has the signature: function(req, payload, done):

• req (Object) - The express request object.
• payload (Object) - An object with the JWT claims.
• done (Function) - A function with signature function(err, secret) to be invoked when the secret is retrieved.
  • err (Any) - The error that occurred.
  • secret (String) - The secret to use to verify the JWT.

For example, if the secret varies based on the JWT issuer:

var jwt = require('express-jwt');
var data = require('./data');
var utilities = require('./utilities');

var secretCallback = function(req, payload, done){
  var issuer = payload.iss;

  data.getTenantByIdentifier(issuer, function(err, tenant){
    if (err) { return done(err); }
    if (!tenant) { return done(new Error('missing_secret')); }

    var secret = utilities.decrypt(tenant.secret);
    done(null, secret);
  });
};

app.get('/protected',
  jwt({secret: secretCallback}),
  function(req, res) {
    if (!req.user.admin) return res.sendStatus(401);
    res.sendStatus(200);
  });

Revoked tokens

It is possible that some tokens will need to be revoked so they cannot be used any longer. You can provide a function as the isRevoked option. The signature of the function is function(req, payload, done):

• req (Object) - The express request object.
• payload (Object) - An object with the JWT claims.
• done (Function) - A function with signature function(err, revoked) to be invoked once the check to see if the token is revoked or not is complete.
  • err (Any) - The error that occurred.
  • revoked (Boolean) - true if the JWT is revoked, false otherwise.

For example, if the (iss, jti) claim pair is used to identify a JWT:

var jwt = require('express-jwt');
var data = require('./data');
var utilities = require('./utilities');

var isRevokedCallback = function(req, payload, done){
  var issuer = payload.iss;
  var tokenId = payload.jti;

  data.getRevokedToken(issuer, tokenId, function(err, token){
    if (err) { return done(err); }
    return done(null, !!token);
  });
};

app.get('/protected',
  jwt({secret: 'shhhhhhared-secret',
    isRevoked: isRevokedCallback}),
  function(req, res) {
    if (!req.user.admin) return res.sendStatus(401);
    res.sendStatus(200);
  });

Error handling

The default behavior is to throw an error when the token is invalid, so you can add your custom logic to manage unauthorized access as follows:

app.use(function (err, req, res, next) {
  if (err.name === 'UnauthorizedError') {
    res.status(401).send('invalid token...');
  }
});

You might want to use this module to identify registered users while still providing access to unregistered users. You can do this by using the option credentialsRequired:

app.use(jwt({
  secret: 'hello world !',
  credentialsRequired: false
}));

Related Modules

• jsonwebtoken — JSON Web Token sign and verification
• express-jwt-permissions - Permissions middleware for JWT tokens

Tests

$ npm install
$ npm test

Contributors

Check them out here

Issue Reporting

If you have found a bug or if you have a feature request, please report them at this repository issues section.

Authors

• this fork: Martin Endler
• original project: Auth0

License

This project is licensed under the MIT license. See the LICENSE file for more info.