django-authlib - Authentication utils for Django

authlib is a collection of authentication utilities for implementing passwordless authentication. This is achieved by either sending cryptographically signed links by email, or by fetching the email address from third party providers such as Google, Facebook and Twitter. After all, what's the point in additionally requiring a password for authentication when the password can be easily resetted on most websites when an attacker has access to the email address?

Goals

• Stay small, simple and extensible.
• Offer tools and utilities instead of imposing a framework on you.

Usage

• Install django-authlib using pip into your virtualenv.
• Add authlib.backends.EmailBackend to AUTHENTICATION_BAcKENDS.
• Adding authlib to INSTALLED_APPS is optional and only useful if you want to use the bundled translation files. There are no required database tables or anything of the sort.
• Have a user model which has a email field named email as username. For convenience a base user model and manager are available in the authlib.base_user module, BaseUser and BaseUserManager. The BaseUserManager is automatically available as objects when you extend the BaseUser.
• Use the bundled views or write your own. The bundled views give feedback using django.contrib.messages, so you may want to check that those messages are visible to the user.

The Google, Facebook and Twitter OAuth clients require the following settings:

• GOOGLE_CLIENT_ID
• GOOGLE_CLIENT_SECRET
• FACEBOOK_CLIENT_ID
• FACEBOOK_CLIENT_SECRET
• TWITTER_CLIENT_ID
• TWITTER_CLIENT_SECRET

Note that you have to configure the Twitter app to allow email access, this is not enabled by default.

Note

If you want to use OAuth2 providers in development mode (without HTTPS) you could add the following lines to your settings.py:

if DEBUG:
    # NEVER set this variable in production environments!
    os.environ["OAUTHLIB_INSECURE_TRANSPORT"] = "1"

This is required because of the strictness of oauthlib which only wants HTTPS URLs (and rightly so).

Use of bundled views

The following URL patterns are an example for using the bundled views. For now you'll have to dig into the code (it's not much, at the time of writing django-authlib's Python code is less than 500 lines):

from django.conf.urls import url
from authlib import views
from authlib.facebook import FacebookOAuth2Client
from authlib.google import GoogleOAuth2Client
from authlib.twitter import TwitterOAuthClient

urlpatterns = [
    url(
        r"^login/$",
        views.login,
        name="login",
    ),
    url(
        r"^oauth/facebook/$",
        views.oauth2,
        {
            "client_class": FacebookOAuth2Client,
        },
        name="accounts_oauth_facebook",
    ),
    url(
        r"^oauth/google/$",
        views.oauth2,
        {
            "client_class": GoogleOAuth2Client,
        },
        name="accounts_oauth_google",
    ),
    url(
        r"^oauth/twitter/$",
        views.oauth2,
        {
            "client_class": TwitterOAuthClient,
        },
        name="accounts_oauth_twitter",
    ),
    url(
        r"^email/$",
        views.email_registration,
        name="email_registration",
    ),
    url(
        r"^email/(?P<code>[^/]+)/$",
        views.email_registration,
        name="email_registration_confirm",
    ),
    url(
        r"^logout/$",
        views.logout,
        name="logout",
    ),
]

Admin OAuth2

The authlib.admin_oauth app allows using Google OAuth2 to allow all users with the same email domain to authenticate for Django's administration interface. You have to use authlib's authentication backend (EmailBackend) for this.

Installation is as follows:

• Follow the steps in the "Usage" section above.
• Add authlib.admin_oauth to your INSTALLED_APPS before django.contrib.admin, so that our login template is picked up.
• Add GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET to your settings as described above.
• Add a ADMIN_OAUTH_PATTERNS setting. The first item is the domain, the second the email address of a staff account. If no matching staff account exists, authentication fails:

ADMIN_OAUTH_PATTERNS = [
    (r"@example\.com$", "[email protected]"),
]

• Add an entry to your URLconf:

urlpatterns = [
    url(r"", include("authlib.admin_oauth.urls")),
    # ...
]

• Add https://yourdomain.com/admin/__oauth__/ as a valid redirect URI in your Google developers console.

Please note that the authlib.admin_oauth.urls module assumes that the admin site is registered at /admin/. If this is not the case you can integrate the view yourself under a different URL.

It is also allowed to use a callable instead of the email address in the ADMIN_OAUTH_PATTERNS setting; the callable is passed the result of matching the regex. If a resulting email address does not exist, authentication (of course) fails:

ADMIN_OAUTH_PATTERNS = [
    (r"^.*@example\.org$", lambda match: match[0]),
]

If a pattern succeeds but no matching user with staff access is found processing continues with the next pattern. This means that you can authenticate users with their individual accounts (if they have one) and fall back to an account for everyone having a Google email address on your domain:

ADMIN_OAUTH_PATTERNS = [
    (r"^.*@example\.org$", lambda match: match[0]),
    (r"@example\.com$", "[email protected]"),
]

You could also remove the fallback line; in this case users can only authenticate if they have a personal staff account.

Little Auth

The authlib.little_auth app contains a basic user model with email as username that can be used if you do not want to write your own user model but still profit from authlib's authentication support.

Usage is as follows:

• Add authlib.little_auth to your INSTALLED_APPS
• Set AUTH_USER_MODEL = "little_auth.User"
• Optionally also follow any of the steps above.

Email Registration

For email registration to work, two templates are needed:

• registration/email_registration_email.txt
• registration/email_registration.html

A starting point would be:

email_registration_email.txt:

Subject (1st line)

Body (3rd line onwards)
{{ url }}
...

email_registration.html:

{% if messages %}
<ul class="messages">
    {% for message in messages %}
    <li{% if message.tags %} class="{{ message.tags }}"{% endif %}>
        {% if message.level == DEFAULT_MESSAGE_LEVELS.ERROR %}Important: {% endif %}
        {{ message }}
    </li>
    {% endfor %}
</ul>
{% endif %}

{% if form.errors and not form.non_field_errors %}
<p class="errornote">
    {% if form.errors.items|length == 1 %}
    {% translate "Please correct the error below." %}
    {% else %}
    {% translate "Please correct the errors below." %}
    {% endif %}
</p>
{% endif %}

{% if form.non_field_errors %}
{% for error in form.non_field_errors %}
<p class="errornote">
    {{ error }}
</p>
{% endfor %}
{% endif %}

<form action='{% url "email_registration" %}' method="post" >
    {% csrf_token %}
    <table>
        {{ form }}
    </table>
    <input type="submit" value="login">
</form>

The above template is inspired from:

• Messages Django documentation
• Django login template

More details are documented in the relevant module.