Create a custom authentication

Question

I'm transferring a database to a new project and more precisely the users. Don't ask me why but the passwords in the old database were hashed with md5 and then with sha256.

I'm using django-rest-auth to manage login.

url(r'^api/rest-auth/', include('rest_auth.urls')),

I added a custom authentication method:

REST_FRAMEWORK = {
  'DEFAULT_AUTHENTICATION_CLASSES': (
     'users.auth.OldCustomAuthentication',
     'rest_framework_jwt.authentication.JSONWebTokenAuthentication',
  )
}

Here is my auth file:

class OldCustomAuthentication(BaseAuthentication):
    def authenticate(self, request):
        try:
            password = request.POST['password']
            email = request.POST['email']
        except MultiValueDictKeyError:
            return None

        if not password or not email:
            return None

        password = hashlib.md5(password.encode())
        password = hashlib.sha256(password.hexdigest().encode())

        try:
            user = User.objects.get(email=email, password=password.hexdigest())
        except User.DoesNotExist:
            return None

        # User is found every time
        print('FOUND USER', user)
        return user, None

But I still get an error when I request http://apiUrl/rest-auth/login/:

{
    "non_field_errors": [
        "Unable to log in with provided credentials."
    ]
}

Do you have any idea? Or maybe I'm doing it in a wrong way.

Thank you in advance.

Jeremy.

Answer 1

Following the advice of @MrName I managed to solve my issue.

So I deleted DEFAULT_AUTHENTICATION_CLASSES in my settings and added this:

 REST_AUTH_SERIALIZERS = {
    'LOGIN_SERIALIZER': 'users.auth.LoginSerializer'
 }

Then I copy pasted the original serializer and modified the function _validate_email with:

def _validate_email(self, email, password):
    user = None

    if email and password:
        user = self.authenticate(email=email, password=password)

        # TODO: REMOVE ONCE ALL USERS HAVE BEEN TRANSFERED TO THE NEW SYSTEM
        if user is None:
            password_hashed = hashlib.md5(password.encode())
            password_hashed = hashlib.sha256(password_hashed.hexdigest().encode())
            try:
                user = User.objects.get(email=email, password=password_hashed.hexdigest())
            except ObjectDoesNotExist:
                user = None
    else:
        msg = _('Must include "email" and "password".')
        raise exceptions.ValidationError(msg)

    return user