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, Microsoft, Facebook and Twitter OAuth clients require the following settings:

• GOOGLE_CLIENT_ID
• GOOGLE_CLIENT_SECRET
• MICROSOFT_CLIENT_ID
• MICROSOFT_CLIENT_SECRET
• FACEBOOK_CLIENT_ID
• FACEBOOK_CLIENT_SECRET
• TWITTER_CLIENT_ID
• TWITTER_CLIENT_SECRET

Microsoft logins accept work, school and personal accounts from any tenant by default. Set MICROSOFT_TENANT_ID to your directory (tenant) ID, which is shown on the app registration's overview page in the Azure portal, to only accept accounts of your organization; the authorization and token endpoints are derived from it. Single-tenant app registrations require this setting.

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.microsoft import MicrosoftOAuth2Client
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/$",
        views.oauth2,
        {
            "client_class": GoogleOAuth2Client,
        },
        name="accounts_oauth_google",
    ),
    url(
        r"^oauth/microsoft/$",
        views.oauth2,
        {
            "client_class": MicrosoftOAuth2Client,
        },
        name="accounts_oauth_microsoft",
    ),
    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 or Microsoft 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$", "admin@example.com"),
]

• 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]),
]

Note the ^.* in the pattern above: the callable is passed the match, not the email address, so match[0] is only the part of the address which the pattern matched. (r"@example\.org$", lambda match: match[0]) returns "@example.org" and therefore never authenticates anyone. Use match.string if you'd rather not anchor the pattern. A system check (authlib.E004) runs the callables in ADMIN_OAUTH_PATTERNS against an example address generated from their pattern and complains if what comes back isn't an email address, so this class of mistake fails manage.py check instead of only failing logins.

Failing logins are logged to the authlib.admin_oauth logger together with the addresses the patterns produced; the message shown in the browser only mentions the visitor's own address, since anyone with an account at the OAuth provider can reach the view.

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$", lambda match: match[0]),
    (r"@example\.com$", "admin@example.com"),
]

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

Disabling passwords in the admin

Single sign-on with an identity provider which enforces MFA is only worth something if a password can't be used instead: as long as Django still accepts one, the MFA is optional in practice. disable_passwords closes the admin site's login form and its password change page:

from django.contrib import admin
from django.urls import include, path

from authlib.admin_oauth.passwords import disable_passwords

disable_passwords(admin.site)

urlpatterns = [
    path("", include("authlib.admin_oauth.urls")),
    path("admin/", admin.site.urls),
    # ...
]

The login page then only shows the single sign-on buttons: no username and password inputs are rendered at all, and a POST with credentials is refused before authenticate() is called, so no password ever reaches an authentication backend. The password change page only explains itself.

Call disable_passwords before the admin site's URLs are built -- at the top of the ROOT_URLCONF module as above, or in an admin.py, which is imported while the apps are loading. The authlib.E012 system check complains if the call came too late for the password change page.

Locally you probably have no OAuth credentials, so skip the call in development:

if not settings.DEBUG:
    disable_passwords(admin.site)

The templates come from authlib.admin_oauth; pass login_template and/or password_change_template to use your own (authlib.E011 tells you if a template cannot be loaded).

Only the admin site is affected. Everything else which sets passwords keeps working: django.contrib.auth's password change and password reset views, the user admin's "change password" form, manage.py changepassword. The first two matter more than they look, since any active staff session gets into the admin whether or not the admin's login form created it -- so manage.py check warns (authlib.W003) when they appear in the URLconf. If the non-staff users of your site do need passwords, silence the check:

SILENCED_SYSTEM_CHECKS = ["authlib.W003"]

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.

Roles

authlib.roles provides a lightweight role-based permission system for staff users. Instead of assigning individual Django permissions to each staff member, you define named roles in AUTHLIB_ROLES and attach a permission-checking callback to each role.

RoleField is a CharField that stores the role on the user model and hooks into Django's permission system. authlib.little_auth.User already includes a role = RoleField() field, so if you use Little Auth you only need to configure the setting.

Setup

Add authlib.backends.RolePermissionsBackend to AUTHENTICATION_BACKENDS, before any backend that checks database-level permissions (such as ModelBackend or EmailBackend):

AUTHENTICATION_BACKENDS = [
    "authlib.backends.RolePermissionsBackend",
    "authlib.backends.EmailBackend",   # or any other auth backend
]

RolePermissionsBackend routes has_perm() calls to the role callback injected by RoleField. It also implements get_all_permissions() by iterating every permission in the database through the callback, which is what drives the Django admin's per-app sidebar visibility.

It answers permission checks and nothing else -- it authenticates nobody, so it has to be accompanied by a backend which does. Add django.contrib.auth.backends.ModelBackend if your project has username/password logins. (Until it was renamed this class extended ModelBackend, so password logins used to run through it, which nothing told you about.)

RolePermissionsBackend must come first for two reasons: it avoids an unnecessary database query when the role callback already has an answer, and it ensures that deny patterns cannot be bypassed by a database-level permission grant that would otherwise short-circuit the check.

Configuration

Add AUTHLIB_ROLES to your settings. Each key is a role identifier; each value is a dict with at minimum a "title" (used as the human-readable choice label) and optionally a "callback" function:

from functools import partial
from django.utils.translation import gettext_lazy as _
from authlib.roles import allow_deny_globs

AUTHLIB_ROLES = {
    "default": {
        "title": _("Default"),
        # No callback → no extra permissions beyond Django's own checks
    },
    "readonly": {
        "title": _("Read-only"),
        # Grant all view permissions, nothing else
        "callback": partial(allow_deny_globs, allow={"*.view_*"}),
    },
    "editor": {
        "title": _("Editor"),
        # Grant everything except user/auth management
        "callback": partial(
            allow_deny_globs,
            allow={"*"},
            deny={"auth.*", "little_auth.*", "admin_sso.*"},
        ),
    },
    "support": {
        "title": _("Support"),
        # Grant all permissions
        "callback": partial(allow_deny_globs, allow={"*"}),
    },
}

The callback receives three keyword arguments: user, perm, and obj. It should return True to grant the permission, raise django.core.exceptions.PermissionDenied to explicitly deny it, or return a falsy value to let Django's normal permission checks continue.

When only one role is defined the RoleField renders as a hidden input in forms, so you can add the field to existing models without cluttering the UI.

allow_deny_globs

authlib.roles.allow_deny_globs is a ready-made callback that matches the permission string ("app_label.codename") against two lists of fnmatch-style glob patterns:

• deny – patterns checked first; a match raises PermissionDenied.
• allow – patterns checked second; a match grants the permission.

Use functools.partial to bind the pattern lists, as shown above.

Because permissions are matched by glob rather than enumerated explicitly, roles automatically cover new models as they are added. For example, an "editor" role with allow={"cms.*"} will grant access to every new CMS plugin model without any manual permission assignment.

Adding RoleField to a custom user model

If you are not using Little Auth, add the field to your own user model:

from authlib.roles import RoleField

class MyUser(AbstractBaseUser, ...):
    role = RoleField()

Then run makemigrations. The field's deconstruct method omits the choices from the migration so that adding or renaming roles does not require a new migration.