greendeploy-django-magiclink 1.3.2

Passwordless authentication for Django with Magic Links

Django MagicLink

Passwordless Authentication for Django with Magic Links.

This package was created with a focus on ease of setup, security and testing (coverage is currently at 100%). The idea is to use sane defaults to quickly create secure single-use token authentication for Django.

Install

pip install django-magiclink

Setup

The setup of the app is simple but has a few steps and a few templates that need overriding.

1. Install the app
2. Configure the app adding urls and settings. There are also a number of additional configuration settings
3. Set up the login page by overriding the login page template
4. Override the login sent page HTML
5. Customise the login failed page
6. Set up the magic link email (optional) by setting the email logo and colours. It's also possible to override the email templates
7. Create a signup page (optional) depending on your settings configuration

Basic login flow

1. The user signs up via the sign up page (This can be skipped if MAGICLINK_REQUIRE_SIGNUP = False)
2. They enter their email on the login page to request a magic link
3. A magic link is sent to users email address
4. The user is redirected to a login sent page
5. The user clicks on the magic link in their email
6. The user is logged in and redirected

If you want to create a different passwordless login flow see the Manual usage section

Configuration

Add to the urlpatterns in urls.py:

urlpatterns = [
    ...
    path('auth/', include('magiclink.urls', namespace='magiclink')),
    ...
]

Add magiclink to your INSTALLED_APPS:

INSTALLED_APPS = (
    ...
    'magiclink',
    ...
)

AUTHENTICATION_BACKENDS = (
    'magiclink.backends.MagicLinkBackend',
    ...
    'django.contrib.auth.backends.ModelBackend',
)

Note: MagicLinkBackend should be placed at the top of AUTHENTICATION_BACKENDS to ensure it is used as the primary login backend.

Add the following settings to your settings.py (you will need to replace the template names in the below steps):

# Set Djangos login URL to the magiclink login page
LOGIN_URL = 'magiclink:login'

MAGICLINK_LOGIN_TEMPLATE_NAME = 'magiclink/login.html'
MAGICLINK_LOGIN_SENT_TEMPLATE_NAME = 'magiclink/login_sent.html'
MAGICLINK_LOGIN_FAILED_TEMPLATE_NAME = 'magiclink/login_failed.html'

# Optional:
# If this setting is set to False a user account will be created the first
# time a user requests a login link.
MAGICLINK_REQUIRE_SIGNUP = True
MAGICLINK_SIGNUP_TEMPLATE_NAME = 'magiclink/signup.html'

See additional configuration settings for all of the different available settings.

Once the app has been added to INSTALLED_APPS you must run the migrations for magiclink

python manage.py migrate magiclink

Login page

Each login page will need different HTML so you need to set the MAGICLINK_LOGIN_TEMPLATE_NAME setting to a template of your own. When overriding this template please ensure the following code is included:

<form action="{% url 'magiclink:login' %}{% if request.GET.next %}?next={{ request.GET.next }}{% endif %}" method="post">
    {% csrf_token %}
    {{ login_form }}
    <button type='submit'>Send login email</button>
</form>

See the login docs if you want to create your own login view

Login sent page

After the user has requested a magic link, they will be redirected to a success page. The HTML for this page can be overridden using the setting MAGICLINK_LOGIN_SENT_TEMPLATE_NAME. It is advised you return a simple message telling the user to check their email:

<h1>Check your email</h1>
<p>We have sent you a magic link to your email address</p>
<p>Please click the link to be logged in automatically</p>

Login failed page

If the user tries to use an invalid magic token they will be shown a custom error page. To override the HTML for this page you can set the MAGICLINK_LOGIN_FAILED_TEMPLATE_NAME setting. If you would like to return a 404 page you can set this setting to a empty string (or any falsy value). If you would like to redirect to another page (say a custom front-end) you can use the MAGICLINK_LOGIN_FAILED_REDIRECT setting.

The reasons for the login failing is passed through as the context variable {{ login_error }}

To help tailor the error page and explain the possible reasons the user could not login the following context variables are provided:

• {{ login_error }} - The reason the login failed (raised by MagicLink.validate())
• {{ one_token_per_user }} - The value of the MAGICLINK_ONE_TOKEN_PER_USER setting
• {{ require_same_browser }} - The value of the MAGICLINK_REQUIRE_SAME_BROWSER setting
• {{ require_same_ip }} - The value of the MAGICLINK_REQUIRE_SAME_IP setting
• {{ allow_superuser_login }} - The value of the MAGICLINK_ALLOW_SUPERUSER_LOGIN setting
• {{ allow_staff_login }} - The value of the MAGICLINK_ALLOW_STAFF_LOGIN setting

For an example of this page see the default login failed template

Magic link email

The login email which includes the magic link needs to be configured. By default, a simple HTML template is used which can be adapted to your own branding using the MAGICLINK_EMAIL_STYLES setting, or you can override the template (see below)

This MAGICLINK_EMAIL_STYLES setting should be a dict with the following key values:

MAGICLINK_EMAIL_STYLES = {
    'logo_url': 'https://example.com/logo.png',
    'background-colour': '#ffffff',
    'main-text-color': '#000000',
    'button-background-color': '#0078be',
    'button-text-color': '#ffffff',
}

Note: The logo URL must be a full URL. For email client support you should use either a jpeg or png.

If this email template is not to your liking you can override the email templates (one for text and one for html). To do so you need to override the MAGICLINK_EMAIL_TEMPLATE_NAME_TEXT and MAGICLINK_EMAIL_TEMPLATE_NAME_HTML settings. If you override these templates the following context variables are available:

• {{ subject }} - The subject of the email "Your login magic link"
• {{ magiclink }} - The magic link URL
• {{ user }} - The full user object
• {{ expiry }} - Datetime for when the magiclink expires
• {{ ip_address }} - The IP address of the person who requested the magic link
• {{ created }} - Datetime of when the magic link was created
• {{ require_same_ip }} - The value of MAGICLINK_REQUIRE_SAME_IP
• {{ require_same_browser }} - The value of MAGICLINK_REQUIRE_SAME_BROWSER
• {{ token_uses }} - The value of MAGICLINK_TOKEN_USES

Signup page

If you want users to have to signup before being able to log in you will want to override the signup page template using the MAGICLINK_SIGNUP_TEMPLATE_NAME setting. This is needed when MAGICLINK_REQUIRE_SIGNUP = True. On successful signup the user will be sent a login email with a magic link.

When overriding this template please ensure the following content is included:

<form action="{% url 'magiclink:signup' %}" method="post">
    {% csrf_token %}
    {{ SignupForm }}
    <button type='submit'>Signup</button>
</form>
<p>Already have an account? <a href='{% url 'magiclink:login' %}'>Log in here</a></p>

There are several forms made avalible in the context on this page depending on what information you want to collect:

• SignupFormEmailOnly - Only includes an email field
• SignupForm - Includes name and email fields
• SignupFormWithUsername - Includes username and email fields
• SignupFormFull - Includes username, name and email fields

Like the login for the sign up flow can be overridden if you require more information from the user on signup. See the login/setup docs for more details.

Configuration settings

Below are the different settings that can be overridden. To do so place the setting into your settings.py.

Note: Each of the url / redirect settings can either be a URL or url name

# Override the login page template. See 'Login page' in the Setup section
MAGICLINK_LOGIN_TEMPLATE_NAME = 'myapp/login.html'

# Override the login page template. See 'Login sent page' in the Setup section
MAGICLINK_LOGIN_SENT_TEMPLATE_NAME = 'myapp/login_sent.html'

# Override the template that shows when the user tries to login with a
# magic link that is not valid. See 'Login failed page' in the Setup section
MAGICLINK_LOGIN_FAILED_TEMPLATE_NAME = 'magiclink/login_failed.html'

# If a login failed redirect is specified the user will be redirected to this
# URL instead of being shown the LOGIN_FAILED_TEMPLATE
MAGICLINK_LOGIN_FAILED_REDIRECT = ''

# If this setting is set to False a user account will be created the first time
# a user requests a login link.
MAGICLINK_REQUIRE_SIGNUP = True
# Override the login page template. See 'Login sent page' in the Setup section
MAGICLINK_SIGNUP_TEMPLATE_NAME = 'myapp/signup.html'

# Set Djangos login redirect URL to be used once the user opens the magic link
# This will be used whenever a ?next parameter is not set on login
LOGIN_REDIRECT_URL = '/accounts/profile/'

# If a new user is created via the signup page use this setting to send them to
# a different url than LOGIN_REDIRECT_URL when clicking the magic link
# This will fall back to LOGIN_REDIRECT_URL
MAGICLINK_SIGNUP_LOGIN_REDIRECT = '/welcome/'

# Change the url a user is redirect to after requesting a magic link
MAGICLINK_LOGIN_SENT_REDIRECT = 'magiclink:login_sent'

# Ensure the branding of the login email is correct. This setting is not needed
# if you override the `login_email.html` template
MAGICLINK_EMAIL_STYLES = {
    'logo_url': '',
    'background-colour': '#ffffff',
    'main-text-color': '#000000',
    'button-background-color': '#0078be',
    'button-text-color': '#ffffff',
}

# If you want to use your own email templates you can override the text and
# html templates used with:
MAGICLINK_EMAIL_TEMPLATE_NAME_TEXT = 'myapp/login_email.text'
MAGICLINK_EMAIL_TEMPLATE_NAME_HTML = 'myapp/login_email.html'

# How long a magic link is valid for before returning an error
MAGICLINK_AUTH_TIMEOUT = 300  # In second - Default is 5 minutes

# Email address is not case sensitive. If this setting is set to True all
# emails addresses will be set to lowercase before any checks are run against it
MAGICLINK_IGNORE_EMAIL_CASE = True

# When creating a user assign their email as the username (if the User model
# has a username field)
MAGICLINK_EMAIL_AS_USERNAME = True

# Allow superusers to login via a magic link
MAGICLINK_ALLOW_SUPERUSER_LOGIN = True

# Allow staff users to login via a magic link
MAGICLINK_ALLOW_STAFF_LOGIN = True

# Ignore the Django user model's is_active flag for login requests
MAGICLINK_IGNORE_IS_ACTIVE_FLAG = True

# Override the default magic link length
# Warning: Overriding this setting has security implications, shorter tokens
# are much more susceptible to brute force attacks*
MAGICLINK_TOKEN_LENGTH = 50

# Require the user email to be included in the verification link
# Warning: If this is set to false tokens are more vulnerable to brute force
MAGICLINK_VERIFY_INCLUDE_EMAIL = True

# Ensure the user who clicked magic link used the same browser as the
# initial login request.
# Note: This can cause issues on devices where the default browser is
# different from the browser being used by the user such as on iOS)
MAGICLINK_REQUIRE_SAME_BROWSER = True

# Ensure the user who clicked magic link has the same IP address as the
# initial login request.
MAGICLINK_REQUIRE_SAME_IP = True

# Remove the last 8-bit octet of a clients IP address.
# Note: This has no effect if MAGICLINK_REQUIRE_SAME_IP as no IP address
# is stored
MAGICLINK_ANONYMIZE_IP = True

# The number of times a login token can be used before being disabled
MAGICLINK_TOKEN_USES = 1

# How often a user can request a new login token (basic rate limiting).
MAGICLINK_LOGIN_REQUEST_TIME_LIMIT = 30  # In seconds

# Disable all other tokens for a user when a new token is requested
MAGICLINK_ONE_TOKEN_PER_USER = True

# Include basic anti spam form fields to help stop bots. False by default
# Note: IF you use the default forms you will need to add CSS to your
# page / stylesheet to hide the labels for the anti spam fields.
# See the login.html or signup.html for an example
MAGICLINK_ANTISPAM_FORMS = False
# The shortest time a user can fill out each field and submit a form without
# being considered a bot. The time is per field and defaults to 1 second.
# This means if the form has 3 fields and the user will need to make more than
# 3 seconds to fill out a form.
MAGICLINK_ANTISPAM_FIELD_TIME = 1

# Override the login verify address. You must inherit from Magiclink LoginVerify
# view. See Manual usage for more details
MAGICLINK_LOGIN_VERIFY_URL = 'magiclink:login_verify'

# If an email address has been added to the unsubscribe table but is also
# assocaited with a Django user, should a login email be sent
MAGICLINK_IGNORE_UNSUBSCRIBE_IF_USER = False

Magic Link cleanup

Each Magic Link is a seperate row in the database. To help give the user a better warning as to why their login was not successful, magic links are not cleared even once they have expired or have been disabled.

To clear old disabled magic links as well as magic links which expired over 1 week ago, you can use the magiclink_clear_logins management command

python manage.py magiclink_clear_logins

Security

Using magic links can be dangerous as poorly implemented login links can be brute-forced and emails can be forwarded by accident. There are several security measures used to mitigate these risks:

• The one-time password issued will be valid for 5 minutes before it expires
• The user's email is specified alongside login tokens to stop URLs being brute-forced
• Each login token will be at least 20 digits
• The initial request and its response must take place from the same IP address
• The initial request and its response must take place in the same browser
• Each one-time link can only be used once
• Only the last one-time link issued will be accepted. Once the latest one is issued, any others are invalidated.

Note: Each of the above settings can be overridden / changed when configuring django-magiclink

Unsubscribe / stopping email spam

Sadly bots like to go around the internet and fill out any forms they can with random email addresses that don't belong to them. Because of this, if an email is added to the MagicLinkUnsubscribe model they will no longer receive a login or welcome email, even if the email has a user associated with it. This behaviour can be changed for existing users using the MAGICLINK_IGNORE_UNSUBSCRIBE_IF_USER setting.

Adding a user to the unsubscribe model is done using the normal Django ORM create method

from magiclink.models import MagicLinkUnsubscribe

MagicLinkUnsubscribe.objects.create(email='[e-mail]')

If you are using the Django Magiclink login or signup functionality, the unsubscribe check happens during form validation. This means a new user will never be created if their email address has already been added to the MagicLinkUnsubscribe list.

Manual usage

Creating magiclinks

django-magiclink uses a model to help create, send and validate magic links. A create_magiclink helper function can be used easily create a MagicLink using the correct settings:

from magiclink.helpers import create_magiclink

# Returns newly created from magiclink.models.MagicLink instance
magiclink = create_magiclink(email, request, redirect_url='')

# Generates the magic link url and sends it in an email
magiclink.send(request)

# If you want to build the magic link from the model instance but don't want to
#  send the email you can you can use:
magic_link_url = magiclink.generate_url(request)

Custom Login verify flow

It is also possible to override the login verify flow to run your own code once the user has successfully logged in instead of a simple redirect. To do this you will need to create a new view which inherits the magiclink.views.LoginVerify view and overrides the login_complete_action method.

The below example will redirect the user to a different page depending on superuser / staff status:

Your own views.py

from magiclink.views import LoginVerify


class CustomLoginVerify(LoginVerify):

    def login_complete_action(self):
        if self.request.user.is_superuser:
            url = reverse('superuser_page')
        elif self.request.user.is_staff:
            url = reverse('staff_page')
        else:
            url = reverse('normal_page')
        return HttpResponseRedirect(url)

Your own urls.py

urlpatterns = [
    ...
    path(
        'custom-login-verify/',
        CustomLoginVerify.as_view(),
        name='custom_login_verify'
    ),
    ...
]

settings.py

...
MAGICLINK_LOGIN_VERIFY_URL = 'custom_login_verify'
...

Upgrading

A new migration was added to version 1.2.0. If you upgrade to 1.2.0 or above from a previous version please ensure you migrate

python manage.py migrate magiclink