Simple middleware to secure django channels 3.0 using Token authentication by simplejwt.

channelmiddleware.py

from rest_framework_simplejwt.tokens import UntypedToken
from django.conf import settings
from jwt import decode as jwt_decode
from urllib.parse import parse_qs
from django.contrib.auth.models import User

from channels.db import database_sync_to_async

@database_sync_to_async
def get_user(user_id):
    try:
        return User.objects.get(id=user_id)
    except User.DoesNotExist:
        return AnonymousUser()

class TokenAuthMiddleware:

    def __init__(self, app):
        # Store the ASGI application we were passed
        self.app = app

    async def __call__(self, scope, receive, send):
        token = parse_qs(scope["query_string"].decode("utf8"))["token"][0]
        UntypedToken(token)
        decoded_data = jwt_decode(token, settings.SECRET_KEY, algorithms=["HS256"])
        print(decoded_data)
        scope['user'] = await get_user(int(decoded_data["user_id"]))

        return await self.app(scope, receive, send)