JWT Key Auth

JWT Key Auth is an answer to the microservice communication problem: how one microservice can authorize itself in another microservices without creating authorization manager service.

jwt-key-auth essentialy works similar to how SSH client and SSH server work together. SSH client signes requests with it's private key, and SSH authorizes client with authorized_keys public keys list.

Practical example

1. Developer wants backend service A to authorize in queue service B.
2. Backend service A install jwt-key-auth, and so queue service B.
3. Developer creates individual pair of keys for service A.
4. Developer mounts private key in service A, and public key in service B.
5. Developer creates JWT token in service A via jwt-key-auth, and sends it to service B.
6. Service B validates received token via jwt-key-auth, and authorizes request or rejects it.

Advantages

jwt-key-auth is lightweight, and easy to use addition to any Node app working with another services, maintained as the same group.

It standarizes way how containers authenticate in each other.

Mounting directories with public keys, and mounting single private key to containers is easy and configurable operation performed by the container. For app it's 100% transparent - it's part of initial configuration.

jwt-key-auth doesn't reinvent the wheel - instead it relies on battle-tested JWT tokens, RSA security and SSH-like protocol.

Library allows for different permissions in different services. By mounting one set of public keys in one container, and another set in another one, developer can build complex authorization schemas.

Installation

npm install --save jwt-key-auth

or

yarn add jwt-key-auth

Usage

jwt-key-auth primary class is JwtKeyAuth, naturally.

Import it by:

import { JwtKeyAuth } from 'jwt-key-auth';

Now, JwtKeyAuth requires two services: one for JWT logic, and another one for key management. Fortunately, jwy-key-auth comes with built-in implementations:

import { JwsAdapter } from 'jwt-key-auth';

import { FileKeyStore } from 'jwt-key-auth';

Now, register everything:

import { JwtKeyAuth, JwsAdapter, FileKeyStore } from 'jwt-key-auth';

async function createAuthService () {
  const jwtService = new JwsAdapter();
  const keyStore = new FileKeyStore();
  const jwtKeyAuth = new JwtKeyAuth(jwtService, keyStore);

  await keyStore.fill('/absolute/path/to/public/keys');
  await keyStore.addPrivateKeyFile('/absolute/path/to/private/key.pem');

  return jwtKeyAuth;
}

(note: instead of using FileKeyStore, you may use KeyStore which manages key, but requires buffers instead of paths to files).

And now, we can start signing and verifying keys:

import { JwtKeyAuth, JwsAdapter, FileKeyStore } from 'jwt-key-auth';

async function createAuthService () {
  const jwtService = new JwsAdapter();
  const keyStore = new FileKeyStore();
  const jwtKeyAuth = new JwtKeyAuth(jwtService, keyStore);

  await keyStore.fill('/absolute/path/to/public/keys');
  await keyStore.addPrivateKeyFile('/absolute/path/to/private/key.pem');

  return jwtKeyAuth;
}

async function main () {
  const thisServiceName = 'my_name';
  const authService = await createAuthService();

  const receivedToken = '...'
  const myToken = await authService.generate(thisServiceName);
  const tokenVerification = await authService.verify(receivedToken);

  console.log(myToken); // token to send to another services
  console.log(tokenVerification); // true or false, depending if it is correct and if we have public key of the receive that wants to access us
}

main();