Question

Previously I have been investigating several solutions how to register with email address instead of username. All the sources I found focus on creating a custom backend and rolling the Signup page. While this works for me, I couldn’t find a single solution that explains what to do with the login screen.

First of all my approach with Email authorization

Registration: I take the email address and create a hash of it as the username and store it.

Login: I take the email address again and create a hash of it and try
to find a username with the same hash.

How its done in code:

In the settings:

AUTHENTICATION_BACKENDS = ('MyApp.auth_backends.CustomUserModelBackend',)
CUSTOM_USER_MODEL = 'MyApp.CustomUser'

In models.py

class CustomUser(User):
    timezone = models.CharField(max_length=50, default='Europe/London')
    objects = UserManager()

I have customized the registration like this:

View.py

def register_page(request):
    if request.method == 'POST':
        form = RegistrationForm(request.POST)
        if form.is_valid():
            user = CustomUser.objects.create_user(
                username=md5(form.cleaned_data['email']).digest().encode('base64')[:-1],
                password=form.cleaned_data['password2'],
                email=form.cleaned_data['email']
            )   

            return HttpResponseRedirect('/register/success/')
    else:
        form = RegistrationForm()
    variables = RequestContext(request, {'form':form})
    return render_to_response('registration/register.html', variables)

in auth_backends.CustomUserModelBackend:

calculate the hash of the given email address to find the related username.

class CustomUserModelBackend(ModelBackend):
    def authenticate(self, username=None, password=None):
        try:
            # The parameter Username is here really just the email address, I get 
            # the hash for the email parameter and try to find the user.

            hash_user = md5(username).digest().encode('base64')[:-1],
            user = self.user_class.objects.get(username=hash_user)
            if user.check_password(password):
                return user
        except self.user_class.DoesNotExist:
            return None

    def get_user(self, user_id):
        try:
            return self.user_class.objects.get(pk=user_id)
        except self.user_class.DoesNotExist:
            return None

    @property
    def user_class(self):
        if not hasattr(self, '_user_class'):
            self._user_class = get_model(*settings.CUSTOM_USER_MODEL.split('.', 2))
            if not self._user_class:
                raise ImproperlyConfigured('Could not get custom user model')
        return self._user_class

Now I am stuck with login screen.

I have done it like this, but I get redirected back to login screen without getting any error shown.

url.py

(r'^login/$', 'django.contrib.auth.views.login'),

registration/login.html

{% extends "base.html" %}
{% block title %}user login{% endblock %}
{% block head %}User login{% endblock %}
{% block content %}{% if form.errors %}
    <p>Your email and password didn't match</p>
{% endif %}
    <form action="." method="post">
        <p>
            <label for="id_username">Email:</label>{{ form.username }}
        </p>
        <p>
            <label for="id_password">Password:</label>{{ form.password }}
        </p>
        {% csrf_token %}
        <input type="hidden" name="next" value="/" />
        <input type="submit" value="login" />
    </form>
{% endblock %}

I know the solution is already problematic since I need an email input for “username” and not a charfield.

1) What do I have to do to override the field type?

2) I still can’t login, it says username doesn’t match password.

I debugged it in Authenticate and it doesnt find the user

            hash_user = md5(username).digest().encode('base64')[:-1],
            user = self.user_class.objects.get(username=hash_user)

Isn’t the hash of the same email address always the same? What could I be missing?

Update:

I can see clearly the hash code is saved as username in the database and I can see how within the Authenticate user = self.user_class.objects.get(username=hash_user) the hashcode is the same value as in the database. However it still doesn’t retrieve the user. Why?

UPDATE 2:

I found the problem. I had one comma there by mistake and that turned the hash into a tuple. Oh dear

This is correct and works:

hash_user = md5(username).digest().encode('base64')[:-1]
user = self.user_class.objects.get(username=hash_user)

We have now the full solution here. Just one thing.

Is anyone able to help me with 1) ? How can I override the username charfield please?

Answer 1

Sadly, this is not currently possible.