I'm building a mobile backend with Django REST Framework (DRF) and I want to use JSON Web Tokens for stateless authentication. Most tutorials point to SimpleJWT, but I want to understand the underlying logic. Is it feasible to write a custom authentication class that handles token signing and validation manually, or is the security risk too high for a production-grade application?
3 answers
You just need to create a class that inherits from BaseAuthentication and implement the authenticate method. It returns a tuple of (user, auth) if successful or None otherwise.
While you can certainly write a custom class by overriding 'BaseAuthentication' and using the 'PyJWT' library, it's generally discouraged for production unless you have a very specific edge case. You would need to manually handle token expiration, secret key rotation, and the 'Authorization' header parsing. SimpleJWT is industry-standard because it handles these security nuances and integrates perfectly with DRF’s permission system. If you do it yourself, ensure you never store sensitive data in the payload since it's only Base64 encoded, not encrypted.
If you go the custom route, how do you plan to handle token blacklisting? That’s usually the hardest part to get right when you aren't using an established library.
Michael, blacklisting usually requires a Redis store or a database table to keep track of logged-out tokens until they expire. If Anthony is building a small project, he might skip blacklisting, but for any real app, it's a security must-have. You’d check the JTI (JWT ID) against your "denylist" during the authentication flow. It's a lot of overhead to manage manually, which is why most of us just stick to the battle-tested libraries like SimpleJWT.
Exactly, Jennifer. It’s a great exercise for learning how DRF middleware works under the hood, even if you eventually switch to a library for the final build.