Sempervirens Authorizer

Middleware for authorizing requests to an Express server.

Installation

npm i @sempervirens/authorizer

Usage

Overview

1. Create JWT private and public keys.

mkdir security && cd security && mkdir jwt && cd jwt
ssh-keygen -t rsa -b 4096 -m PEM -f jwtRS256.key
openssl rsa -in jwtRS256.key -pubout -outform PEM -out jwtRS256.key.pub

2. Import authorizer into the server's main file, and then initialize authorizer with the JWT public and private keys.

3. Set up a route that uses authorizer.encrypt to create a token and return the token to the client.

4. Set up another route with a protected resource that requires a valid token.

5. From the client, send a request to the server to get the token.

6. From the client, send a second request for the protected resource, including the 'Authorization': 'Bearer ${token}' header.

Example

import { readFileSync } from 'fs';
import express from 'express';
import authorizer from '@sempervirens/authorizer';

const jwtPublicKey = readFileSync('./security/jwt/jwtRS256.key.pub', 'utf8');
const jwtPrivateKey = readFileSync('./security/jwt/jwtRS256.key', 'utf8');

authorizer.init({ jwtPublicKey, jwtPrivateKey });

const app = express();
app.use(express.json());

// Set up a /login route
app.post('/login', async (req, res, next) => {
  const { email, password } = req.body;
  // Validate email/password combination; do not use the following except for testing
  const isValid = email == '[email protected]' && password == 'testpassword';
  if (isValid) {
    const token = authorizer.encrypt({
      expiresIn: '10m',
      data: { email }
    });
    res.json({ token });
  } else {
    res.json({ error: 'Invalid credentials' });
  }
});

// Set up a protected resource route
app.get('/profile/:id', async (req, res, next) => {
  if (authorizer.isAuthorized(req)) { // Pass request header 'Authorization': 'Bearer ${token}'
    const profile = {
      email: '[email protected]',
      name: 'FirstTest LastTest'
    };
    res.json({ profile });
  } else {
    authorizer.sendUnauthorized(res); // Or send a custom response
  }
});

API

authorizer (Singleton instance)

| Prop | Type | Params | Description | |-------|------|--------|-------------| | init | function | { jwtPublicKey = '', jwtPrivateKey = '' } | Initializes the instance properties. | | encrypt | function | { expiresIn = '', data: {} } | Returns a JWT token. | | decrypt | function | tokenOrReq | Decrypts a JWT token. The token itself or an Express request object containing the authorization header may be given. | | isValid | function | tokenOrReq | Returns true or false. The token itself or an Express request object containing the authorization header may be given. | | invalidate | function | tokenOrReq | Invalidates a token within authorizer. | | reset | function | tokenOrReq | Decrypts the original token, calculates the original token's expiresIn, and adds the origIat property to the data before generating a new token. | | isAuthorized | function | req: express.Request | Parses a token from the 'Authorization': 'Bearer ${token}', checks if it's valid, and returns true or false. | | authorize | function | req: express.Request, res: express.Request, next | Checks if the token is valid. If so, it calls next. If not, it calls sendUnauthorized.| | sendUnauthorized | function | res: express.Request | Sends a 401 response with a pre-formatted data object in the same shape as @sempervirens/endpoint's error response. |