nodejs authorization middleware

Basic authorization middleware providing security to protected API. Require token passed in header, validate decrypted token information with secret and validate user existence in mocked data simulating database fetch).

rpichioli
2
0
JavaScript

nodejs-authorization-middleware

This project shows how to implement middleware within NodeJS + Express server and how to build basic authorization middleware.

The objective is to support developers in how to build a complete flow applying auth concepts within NodeJS and apply NodeJS concepts too.

Important Notes

Basically we have an unprotected entry-point to validate user and provide token (login) in response, and one protected endpoint working under the middleware that expose content if authorized and authenticated, otherwise the response ends in validation.

The focus is not to work with database and interface - I have mocked an user simulating some database data in login route (/users/login) that must be used to enter successfully the application.

With a valid token in hand (logged) you can request protected routes (/users/) providing the key authorization and value Bearer [token_goes_here] in your request header. The middleware verify the token existence in header, extract it, validate it’s integrity with the secret used to generate it and validate user deciding if the request can go on or stop at this point, negating any contact.

Middlewares

1. CORS - Provide pre-configured access globally to origin, methods and headers for all requests (allowed in this app). Located at:

/middleware/cors.js

2. Authorization - Our authorization middleware properly, located at:

/middleware/auth.js

Token

Another important point is that I’m using jsonwebtoken to generate and verify token. The token generation is based in a secret that I have saved as a js module located at:

/config/security.js

Tests

You can test the authorization middleware providing a false token to protected API or providing wrong information to login, different from the mocked data. I have working API tests built in Postman that I have exported and saved under the folder:

/postman_tests/nodejs-authorization-middleware.postman_collection.json

Business Rules

Authentication Middleware

  • Validate Bearer token received from request header through authorization key;
  • Extract token and try to decode it - Using the secret that generates the cryptography at the first time with jsonwebtoken;
  • Grants authorization to protected services, or deny it if something is going wrong;
  • Suggestions for most advanced implementations: You can verify if token is granted in database, you can expire it if passed some time without access, you can work with 2 tokens - one for access and one for authorization - returning the access for user, and more…

Login (authorization) API

  • Validate posted received data from request;
  • Verify if user exists and password cryptography is OK;
  • Return 200 response exposing token and boolean success with true, or treated error;
  • Suggestions for most advanced implementations: Save into database, set expiration rules.

Developed by

Rodrigo Quiñones Pichioli, since Jan/2019