Django Custom Authentication not working

Question

I am trying to implementing django custom authentication with custom user model using JWT. I have written CustomUser model and CustomAuthBackend and configured for using JWT.

Below is the snapshot of project's settings.py :

AUTH_USER_MODEL = 'users.CustomUser'
AUTHENTICATION_BACKENDS = ('project.users.backends.CustomAuthBackend', )

REST_FRAMEWORK = {
    'DEFAULT_PERMISSION_CLASSES': (
        'rest_framework.permissions.IsAuthenticated',
    ),
    'DEFAULT_AUTHENTICATION_CLASSES': (
        'rest_framework_jwt.authentication.JSONWebTokenAuthentication',
    ),
}

JWT_AUTH = {
            'JWT_EXPIRATION_DELTA': datetime.timedelta(hours=1),
            'JWT_ALLOW_REFRESH': True,
        }

REST_USE_JWT = True

LOGGING = {
        'version': 1,
        'handlers': {
            'file': {
                'level': 'DEBUG',
                'class': 'logging.FileHandler',
                'filename': 'debug.log',
                },
            },
        'loggers': {
            'django': {
                'handlers': ['file'],
                'level': 'DEBUG',
                'propagate': True,
               },
           },
        }

Before using custom authentication, I created 2 users and after implementing custom authentication trying to login (http://127.0.0.1:8000/admin/) using one of those credentials but getting "Please enter the correct email and password for a staff account. Note that both fields may be case-sensitive." message.

Trying to debug the custom authentication but even prints are not coming on console. Also tried using logging module but its also not working. So I doubt that my custom authentication function def authenticate(self, request, email, password) itself might not being called.

Here is the code for that:

from project.users.models import CustomUser
from rest_framework import authentication
import logging


class CustomAuthBackend(object):
    def authenticate(self, request, email, password):
        # Get an instance of a logger
        print ("Inside CustomAuthBackEnd")
        logger = logging.getLogger(__name__)
        logger.info("Authenticating user........")
        print >> sys.stderr, "debug the error"
        try:
            user = CustomUser.objects.get(email=email)
            print("__name__: ", __name__)
            print("email: ", email)
            print("user: ", user)
            if user.check_password(password):
                return user
            else:
                return None
        except CustomUser.DoesNotExist:
            logger.error("user with login %s does not exists " % login)
            return None

        except Exception as e:
            logger.error(repr(e))
            return None

    def get_user(self, user_id):
        logger.info("Getting user........")
        try:
            user = CustomUser.objects.get(pk=user_id)
            #user = CustomUser.objects.get(sys_id=user_id)
            return user
            #if user.is_active:
            #    return user

            #return None

        except CustomUser.DoesNotExist:
            logger.error("user with %(user_id)d not found")
            return None;

Can someone please tell whether def authenticate(self, request, email, password) function is called or not or how can I debug it ?

Version used: django=2.0.1 djangorestframework==3.7.7 Python 3.4.3

You say you're using Python 3.4.3... the print >> sys.stderr, "debug the error" isn't valid use of print - you should get an exception about not being able to apply the >> operator between a function and sys.stderr - so I'd expect you'd get an exception fairly quickly if it was running fine. — Jon Clements♦
Actually I did a lot of debugging to print the logs if possible so I tried print >> sys.stderr, "debug the error" also but it did not work . I copy pasted the code here so it remained there. Though I didn't get any exception. — Satendra Pratap
Trying shoving a print at the top of the file with your custom auth in it and make sure it's actually under where it's expected...make sure the server's reloaded to ensure it's only using certain auth backends and it's probably worth clearing out your sessions table... — Jon Clements♦
Thanks @JonClements I put the print on the top in the Custom Authentication file. Cleared all sessions using "python3 manage.py clearsessions" command and ran the server again but no luck. — Satendra Pratap

Satendra Pratap Satendra Pratap · Accepted Answer · 2018-02-26T10:14:03

Tried lot of things but what worked is the Django Shell.

Run "python3 manage.py shell" and you will come into shell prompt.

Now because I have implemented Custom Authentication so if I import from django.contrib.auth import authenticate and call authenticate function from shell prompt then my custom authentication function should be called (if everything implemented and configured properly). I tried same and prints started coming.

Earlier what was happening was that authenticate function was not being called itself and hence prints were not coming.

The reason I could figure out was that I implemented it as def authenticate(self, request, email, password) but if I call it (from shell) as authenticate(username="root", password="password123") it wont be called but if I call as authenticate(email="[email protected]", password="password123") then it will be called and internally Django framework might be calling it the first way.

I am new to python, django so i don't know whats happening inside but looks like paramater names while calling a function should match the arguments names in function definition.

Django Custom Authentication not working

1 Answers