tramway-authentication-auth0-api

Tramway Authentication: Auth0 API is a simple implementation of the Auth0 policies on API routes for the tramway framework. It includes:

1. A PolicyFactory for easily creating policies and adding scopes
2. A Security middleware for the ExpressServerStrategy of tramway-core-router.

Installation:

1. npm install tramway-authentication-auth0-api

Documentation

Recommended Folder Structure

• config
• policies
• routes

Getting Started

1. Create a resource server API in the APIs section of your Auth0 dashboard. This library was designed to use RS256 signing for JWT tokens. All of the implementation under Add API Authorization in the Auth0 docs are handled by this library - including scopes.

2. In your tramway app, import the replacement Security middleware and pass it to the ExpressServerStrategy. This should be in your server.js file.

import {Security} from 'tramway-authentication-auth0-api';

let router = new Router(routes, new ExpressServerStrategy(app, Security));

1. Create and populate your local .env file with the following:

AUTH0_AUDIENCE=API_IDENTIFIER
AUTH0_DOMAIN=DOMAIN

1. Create a security.js file in your config folder and export a JSON config using the data given from Auth0. Leave out the function calls so the file looks as follows (with your settings in the placeholders).

require('dotenv').config();

if (!process.env.AUTH0_DOMAIN || !process.env.AUTH0_AUDIENCE) {
  throw 'Make sure you have AUTH0_DOMAIN, and AUTH0_AUDIENCE in your .env file';
}

export default {
    audience: process.env.AUTH0_AUDIENCE,
    issuer: `https://${process.env.AUTH0_DOMAIN}/`,
    secret: {
        jwksUri: `https://${process.env.AUTH0_DOMAIN}/.well-known/jwks.json`
    }
};

1. Create a policies.js file in the policies folder and accompany it with an index.js for convenience. Here we will create the policies using the PolicyFactory. Pass the security configuration from step 2 directly to the factory.

import {PolicyFactory} from 'tramway-authentication-auth0-api';
import {security} from '../config';

let policyFactory = new PolicyFactory(security);

export default {
    LOGGED_IN_POLICY: policyFactory.buildBasic(),
    CAN_WRITE_POLICY: policyFactory.buildScoped(['write:hello'])
};

1. Import the policies to your routes.js file in the routes folder.

import policies from '../policies';

let {LOGGED_IN_POLICY, CAN_WRITE_POLICY} = policies;

You can then use the policy on a route using the policy key.

"policy": CAN_WRITE_POLICY

PolicyFactory

The PolicyFactory simplifies the creation of policies by streamlining prerequisites.

import {PolicyFactory} from 'tramway-authentication-auth0-api;

The constructor takes a config object of the following form:

{
    audience: 'http://localhost:8081',
    issuer: `https://YOURAPPNAME.auth0.com/`,
    secret: {
        jwksUri: `https://YOURAPPNAME.auth0.com/.well-known/jwks.json`
    }
};

Other settings in the secret can be overrided as per the jwt api. The defaults are:

cache: true,
rateLimit: true,
jwksRequestsPerMinute: 5,

Function	Parameters	Default	Return	Description
buildBasic			AccessTokenPolicy	Performs basic authentication based on whether the Bearer token is valid.
buildScoped	scopes: string[]		CompositePolicy	Performs basic authentication, then checks if the proper scope is applied.

Providers

import {providers} from 'tramway-authentication-auth0-api';
{JwtProvider, ScopesProvider} = providers;

JwtProvider

Handles interaction with the jwt libraries to create the checkToken middleware.

The constructor takes a config object of the following form:

{
    audience: 'http://localhost:8081',
    issuer: `https://YOURAPPNAME.auth0.com/`,
    secret: {
        jwksUri: `https://YOURAPPNAME.auth0.com/.well-known/jwks.json`
    }
};

The checkToken method is generated when the object is constructed and returns an Express RouteHandler callback.

ScopesProvider

Handles interaction with express-jwt-authz to create the checkScopes middleware.

The constructor takes an array of strings representing the scopes you can set up in the Auth0 dashboard.

Policies

AccessTokenPolicy

The AccessTokenPolicy handles the validity of the a Bearer token on a given Route. It expects a JwtProvider as its constructor argument and check returns the middleware from JwtProvider.checkToken.

ProperScopePolicy

The ProperScopePolicy handles the validity of the token's scope. It expects a ScopesProvider as its constructor argument and check returns the middleware from ScopesProvider.checkScopes.

CompositePolicy

The CompositePolicy allows for multiple policies to be put together to form a sequenced middleware. It takes an array of AuthenticationStrategy objects or alternatively lets you add AuthenticationStrategy objects via its add function. Its check returns an array of the middleware that is added to it.

Errors

The following errors will be thrown in the following cases:

Error	Condition
InvalidArgumentError	The configuration passed to JwtProvider is wrong. Be sure to follow the aforementioned guidelines.
UnsupportedProviderError	The provider set in one of the policies doesn't match its expected provider type.