This document explains the usage of Django’s authentication system in its default configuration. This configuration has evolved to serve the most common project needs, handling a reasonably wide range of tasks, and has a careful implementation of passwords and permissions, and can handle many projects as is. For projects where authentication needs differ from the default, Django supports extensive extension and customization of authentication.
Django authentication provides both authentication and authorization, together and is generally referred to as the authentication system, as these features somewhat coupled.
User
objects are the core of the
authentication system. They typically represent the people interacting with
your site and are used to enable things like restricting access, registering
user profiles, associating content with creators etc. Only one class of user
exists in Django’s authentication framework, i.e., ‘superusers’ or admin
‘staff’ users are just user objects with special attributes set, not different
classes of user objects.
The primary attributes of the default user are:
See the full API documentation
for
full reference, the documentation that follows is more task oriented.
The most direct way to create users is to use the included
create_user()
helper function:
>>> from django.contrib.auth.models import User
>>> user = User.objects.create_user('john', 'lennon@thebeatles.com', 'johnpassword')
# At this point, user is a User object that has already been saved
# to the database. You can continue to change its attributes
# if you want to change other fields.
>>> user.last_name = 'Lennon'
>>> user.save()
If you have the Django admin installed, you can also create users interactively.
manage.py syncdb
prompts you to create a superuser the
first time you run it with 'django.contrib.auth'
in your
INSTALLED_APPS
. If you need to create a superuser at a later date,
you can use a command line utility:
manage.py createsuperuser --username=joe --email=joe@example.com
You will be prompted for a password. After you enter one, the user will be
created immediately. If you leave off the --username
or the
--email
options, it will prompt you for those values.
Django does not store raw (clear text) passwords on the user model, but only a hash (see documentation of how passwords are managed for full details). Because of this, do not attempt to manipulate the password attribute of the user directly. This is why a helper function is used when creating a user.
To change a user’s password, you have several options:
manage.py changepassword *username*
offers a method
of changing a User’s password from the command line. It prompts you to
change the password of a given user which you must enter twice. If
they both match, the new password will be changed immediately. If you
do not supply a user, the command will attempt to change the password
whose username matches the current system user.
You can also change a password programmatically, using
set_password()
:
>>> from django.contrib.auth.models import User
>>> u = User.objects.get(username__exact='john')
>>> u.set_password('new password')
>>> u.save()
If you have the Django admin installed, you can also change user’s passwords on the authentication system’s admin pages.
Django also provides views and forms that may be used to allow users to change their own passwords.
authenticate
(**credentials)¶To authenticate a given username and password, use
authenticate()
. It takes credentials in the
form of keyword arguments, for the default configuration this is
username
and password
, and it returns
a User
object if the password is valid
for the given username. If the password is invalid,
authenticate()
returns None
. Example:
from django.contrib.auth import authenticate
user = authenticate(username='john', password='secret')
if user is not None:
# the password verified for the user
if user.is_active:
print("User is valid, active and authenticated")
else:
print("The password is valid, but the account has been disabled!")
else:
# the authentication system was unable to verify the username and password
print("The username and password were incorrect.")
Django comes with a simple permissions system. It provides a way to assign permissions to specific users and groups of users.
It’s used by the Django admin site, but you’re welcome to use it in your own code.
The Django admin site uses permissions as follows:
Permissions can be set not only per type of object, but also per specific
object instance. By using the
has_add_permission()
,
has_change_permission()
and
has_delete_permission()
methods provided
by the ModelAdmin
class, it is possible to
customize permissions for different object instances of the same type.
User
objects have two many-to-many
fields: groups
and user_permissions
.
User
objects can access their related
objects in the same way as any other Django model:
myuser.groups = [group_list]
myuser.groups.add(group, group, ...)
myuser.groups.remove(group, group, ...)
myuser.groups.clear()
myuser.user_permissions = [permission_list]
myuser.user_permissions.add(permission, permission, ...)
myuser.user_permissions.remove(permission, permission, ...)
myuser.user_permissions.clear()
When django.contrib.auth
is listed in your INSTALLED_APPS
setting, it will ensure that three default permissions – add, change and
delete – are created for each Django model defined in one of your installed
applications.
These permissions will be created when you run manage.py syncdb
; the first time you run syncdb
after adding
django.contrib.auth
to INSTALLED_APPS
, the default permissions
will be created for all previously-installed models, as well as for any new
models being installed at that time. Afterward, it will create default
permissions for new models each time you run manage.py syncdb
.
Assuming you have an application with an
app_label
foo
and a model named Bar
,
to test for basic permissions you should use:
user.has_perm('foo.add_bar')
user.has_perm('foo.change_bar')
user.has_perm('foo.delete_bar')
The Permission
model is rarely accessed
directly.
django.contrib.auth.models.Group
models are a generic way of
categorizing users so you can apply permissions, or some other label, to those
users. A user can belong to any number of groups.
A user in a group automatically has the permissions granted to that group. For
example, if the group Site editors
has the permission
can_edit_home_page
, any user in that group will have that permission.
Beyond permissions, groups are a convenient way to categorize users to give
them some label, or extended functionality. For example, you could create a
group 'Special users'
, and you could write code that could, say, give them
access to a members-only portion of your site, or send them members-only email
messages.
While custom permissions can be defined within
a model’s Meta
class, you can also create permissions directly. For
example, you can create the can_publish
permission for a BlogPost
model
in myapp
:
from django.contrib.auth.models import Group, Permission
from django.contrib.contenttypes.models import ContentType
content_type = ContentType.objects.get(app_label='myapp', model='BlogPost')
permission = Permission.objects.create(codename='can_publish',
name='Can Publish Posts',
content_type=content_type)
The permission can then be assigned to a
User
via its user_permissions
attribute or to a Group
via its
permissions
attribute.
Django uses sessions and middleware to hook the
authentication system into request objects
.
These provide a request.user
attribute
on every request which represents the current user. If the current user has not
logged in, this attribute will be set to an instance
of AnonymousUser
, otherwise it will be an
instance of User
.
You can tell them apart with
is_authenticated()
, like so:
if request.user.is_authenticated():
# Do something for authenticated users.
else:
# Do something for anonymous users.
If you have an authenticated user you want to attach to the current session
- this is done with a login()
function.
login
()¶To log a user in, from a view, use login()
. It
takes an HttpRequest
object and a
User
object.
login()
saves the user’s ID in the session,
using Django’s session framework.
Note that any data set during the anonymous session is retained in the session after a user logs in.
This example shows how you might use both
authenticate()
and
login()
:
from django.contrib.auth import authenticate, login
def my_view(request):
username = request.POST['username']
password = request.POST['password']
user = authenticate(username=username, password=password)
if user is not None:
if user.is_active:
login(request, user)
# Redirect to a success page.
else:
# Return a 'disabled account' error message
else:
# Return an 'invalid login' error message.
Calling authenticate()
first
When you’re manually logging a user in, you must call
authenticate()
before you call
login()
.
authenticate()
sets an attribute on the User
noting
which authentication backend successfully authenticated that user (see the
backends documentation for details), and
this information is needed later during the login process. An error will be
raise if you try to login a user object retrieved from the database
directly.
logout
()¶To log out a user who has been logged in via
django.contrib.auth.login()
, use
django.contrib.auth.logout()
within your view. It takes an
HttpRequest
object and has no return value.
Example:
from django.contrib.auth import logout
def logout_view(request):
logout(request)
# Redirect to a success page.
Note that logout()
doesn’t throw any errors if
the user wasn’t logged in.
When you call logout()
, the session data for
the current request is completely cleaned out. All existing data is
removed. This is to prevent another person from using the same Web browser
to log in and have access to the previous user’s session data. If you want
to put anything into the session that will be available to the user
immediately after logging out, do that after calling
django.contrib.auth.logout()
.
The simple, raw way to limit access to pages is to check
request.user.is_authenticated()
and either redirect to a
login page:
from django.shortcuts import redirect
def my_view(request):
if not request.user.is_authenticated():
return redirect('/login/?next=%s' % request.path)
# ...
...or display an error message:
from django.shortcuts import render
def my_view(request):
if not request.user.is_authenticated():
return render(request, 'myapp/login_error.html')
# ...
login_required
([redirect_field_name=REDIRECT_FIELD_NAME, login_url=None])¶As a shortcut, you can use the convenient
login_required()
decorator:
from django.contrib.auth.decorators import login_required
@login_required
def my_view(request):
...
login_required()
does the following:
settings.LOGIN_URL
, passing the current absolute
path in the query string. Example: /accounts/login/?next=/polls/3/
.By default, the path that the user should be redirected to upon
successful authentication is stored in a query string parameter called
"next"
. If you would prefer to use a different name for this parameter,
login_required()
takes an
optional redirect_field_name
parameter:
from django.contrib.auth.decorators import login_required
@login_required(redirect_field_name='my_redirect_field')
def my_view(request):
...
Note that if you provide a value to redirect_field_name
, you will most
likely need to customize your login template as well, since the template
context variable which stores the redirect path will use the value of
redirect_field_name
as its key rather than "next"
(the default).
login_required()
also takes an
optional login_url
parameter. Example:
from django.contrib.auth.decorators import login_required
@login_required(login_url='/accounts/login/')
def my_view(request):
...
Note that if you don’t specify the login_url
parameter, you’ll need to
ensure that the settings.LOGIN_URL
and your login
view are properly associated. For example, using the defaults, add the
following line to your URLconf:
(r'^accounts/login/$', 'django.contrib.auth.views.login'),
The settings.LOGIN_URL
also accepts
view function names and named URL patterns.
This allows you to freely remap your login view within your URLconf
without having to update the setting.
Note
The login_required decorator does NOT check the is_active flag on a user.
To limit access based on certain permissions or some other test, you’d do essentially the same thing as described in the previous section.
The simple way is to run your test on request.user
in the view directly. For example, this view
checks to make sure the user has an email in the desired domain:
def my_view(request):
if not '@example.com' in request.user.email:
return HttpResponse("You can't vote in this poll.")
# ...
user_passes_test
(func[, login_url=None])¶As a shortcut, you can use the convenient user_passes_test
decorator:
from django.contrib.auth.decorators import user_passes_test
def email_check(user):
return '@example.com' in user.email
@user_passes_test(email_check)
def my_view(request):
...
user_passes_test()
takes a required
argument: a callable that takes a
User
object and returns True
if
the user is allowed to view the page. Note that
user_passes_test()
does not
automatically check that the User
is
not anonymous.
user_passes_test()
takes an
optional login_url
argument, which lets you specify the URL for your
login page (settings.LOGIN_URL
by default).
For example:
@user_passes_test(email_check, login_url='/login/')
def my_view(request):
...
permission_required
([login_url=None, raise_exception=False])¶It’s a relatively common task to check whether a user has a particular
permission. For that reason, Django provides a shortcut for that case: the
permission_required()
decorator.:
from django.contrib.auth.decorators import permission_required
@permission_required('polls.can_vote')
def my_view(request):
...
As for the has_perm()
method,
permission names take the form "<app label>.<permission codename>"
(i.e. polls.can_vote
for a permission on a model in the polls
application).
Note that permission_required()
also takes an optional login_url
parameter. Example:
from django.contrib.auth.decorators import permission_required
@permission_required('polls.can_vote', login_url='/loginpage/')
def my_view(request):
...
As in the login_required()
decorator,
login_url
defaults to settings.LOGIN_URL
.
Added raise_exception
parameter. If given, the decorator will raise
PermissionDenied
, prompting
the 403 (HTTP Forbidden) view instead of
redirecting to the login page.
To apply a permission to a class-based generic view, decorate the View.dispatch
method on the class. See
Decorating the class for details.
Django provides several views that you can use for handling login, logout, and password management. These make use of the stock auth forms but you can pass in your own forms as well.
Django provides no default template for the authentication views - however the template context is documented for each view below.
The built-in views all return
a TemplateResponse
instance, which allows
you to easily customize the response data before rendering. For more details,
see the TemplateResponse documentation.
Most built-in authentication views provide a URL name for easier reference. See the URL documentation for details on using named URL patterns.
login
(request[, template_name, redirect_field_name, authentication_form])¶URL name: login
See the URL documentation for details on using named URL patterns.
Here’s what django.contrib.auth.views.login
does:
GET
, it displays a login form that POSTs to the
same URL. More on this in a bit.POST
with user submitted credentials, it tries to log
the user in. If login is successful, the view redirects to the URL
specified in next
. If next
isn’t provided, it redirects to
settings.LOGIN_REDIRECT_URL
(which
defaults to /accounts/profile/
). If login isn’t successful, it
redisplays the login form.It’s your responsibility to provide the html for the login template
, called registration/login.html
by default. This template gets passed
four template context variables:
form
: A Form
object representing the
AuthenticationForm
.next
: The URL to redirect to after successful login. This may
contain a query string, too.site
: The current Site
,
according to the SITE_ID
setting. If you don’t have the
site framework installed, this will be set to an instance of
RequestSite
, which derives the
site name and domain from the current
HttpRequest
.site_name
: An alias for site.name
. If you don’t have the site
framework installed, this will be set to the value of
request.META['SERVER_NAME']
.
For more on sites, see The “sites” framework.If you’d prefer not to call the template registration/login.html
,
you can pass the template_name
parameter via the extra arguments to
the view in your URLconf. For example, this URLconf line would use
myapp/login.html
instead:
(r'^accounts/login/$', 'django.contrib.auth.views.login', {'template_name': 'myapp/login.html'}),
You can also specify the name of the GET
field which contains the URL
to redirect to after login by passing redirect_field_name
to the view.
By default, the field is called next
.
Here’s a sample registration/login.html
template you can use as a
starting point. It assumes you have a base.html
template that
defines a content
block:
{% extends "base.html" %}
{% block content %}
{% if form.errors %}
<p>Your username and password didn't match. Please try again.</p>
{% endif %}
<form method="post" action="{% url 'django.contrib.auth.views.login' %}">
{% csrf_token %}
<table>
<tr>
<td>{{ form.username.label_tag }}</td>
<td>{{ form.username }}</td>
</tr>
<tr>
<td>{{ form.password.label_tag }}</td>
<td>{{ form.password }}</td>
</tr>
</table>
<input type="submit" value="login" />
<input type="hidden" name="next" value="{{ next }}" />
</form>
{% endblock %}
If you have customized authentication (see
Customizing Authentication) you can pass a custom authentication form
to the login view via the authentication_form
parameter. This form must
accept a request
keyword argument in its __init__
method, and
provide a get_user
method which returns the authenticated user object
(this method is only ever called after successful form validation).
logout
(request[, next_page, template_name, redirect_field_name])¶Logs a user out.
URL name: logout
Optional arguments:
next_page
: The URL to redirect to after logout.template_name
: The full name of a template to display after
logging the user out. Defaults to
registration/logged_out.html
if no argument is supplied.redirect_field_name
: The name of a GET
field containing the
URL to redirect to after log out. Overrides next_page
if the given
GET
parameter is passed.Template context:
title
: The string “Logged out”, localized.site
: The current Site
,
according to the SITE_ID
setting. If you don’t have the
site framework installed, this will be set to an instance of
RequestSite
, which derives the
site name and domain from the current
HttpRequest
.site_name
: An alias for site.name
. If you don’t have the site
framework installed, this will be set to the value of
request.META['SERVER_NAME']
.
For more on sites, see The “sites” framework.logout_then_login
(request[, login_url])¶Logs a user out, then redirects to the login page.
URL name: No default URL provided
Optional arguments:
login_url
: The URL of the login page to redirect to.
Defaults to settings.LOGIN_URL
if not supplied.password_change
(request[, template_name, post_change_redirect, password_change_form])¶Allows a user to change their password.
URL name: password_change
Optional arguments:
template_name
: The full name of a template to use for
displaying the password change form. Defaults to
registration/password_change_form.html
if not supplied.post_change_redirect
: The URL to redirect to after a successful
password change.password_change_form
: A custom “change password” form which must
accept a user
keyword argument. The form is responsible for
actually changing the user’s password. Defaults to
PasswordChangeForm
.Template context:
form
: The password change form (see password_change_form
above).password_change_done
(request[, template_name])¶The page shown after a user has changed their password.
URL name: password_change_done
Optional arguments:
template_name
: The full name of a template to use.
Defaults to registration/password_change_done.html
if not
supplied.password_reset
(request[, is_admin_site, template_name, email_template_name, password_reset_form, token_generator, post_reset_redirect, from_email])¶Allows a user to reset their password by generating a one-time use link that can be used to reset the password, and sending that link to the user’s registered email address.
set_unusable_password()
will not be able to request a password reset to prevent misuse
when using an external authentication source like LDAP.URL name: password_reset
Optional arguments:
template_name
: The full name of a template to use for
displaying the password reset form. Defaults to
registration/password_reset_form.html
if not supplied.
email_template_name
: The full name of a template to use for
generating the email with the reset password link. Defaults to
registration/password_reset_email.html
if not supplied.
subject_template_name
: The full name of a template to use for
the subject of the email with the reset password link. Defaults
to registration/password_reset_subject.txt
if not supplied.
password_reset_form
: Form that will be used to get the email of
the user to reset the password for. Defaults to
PasswordResetForm
.
token_generator
: Instance of the class to check the one time link.
This will default to default_token_generator
, it’s an instance of
django.contrib.auth.tokens.PasswordResetTokenGenerator
.
post_reset_redirect
: The URL to redirect to after a successful
password reset request.
from_email
: A valid email address. By default Django uses
the DEFAULT_FROM_EMAIL
.
Template context:
form
: The form (see password_reset_form
above) for resetting
the user’s password.Email template context:
email
: An alias for user.email
user
: The current User
,
according to the email
form field. Only active users are able to
reset their passwords (User.is_active is True
).site_name
: An alias for site.name
. If you don’t have the site
framework installed, this will be set to the value of
request.META['SERVER_NAME']
.
For more on sites, see The “sites” framework.domain
: An alias for site.domain
. If you don’t have the site
framework installed, this will be set to the value of
request.get_host()
.protocol
: http or httpsuid
: The user’s id encoded in base 36.token
: Token to check that the reset link is valid.Sample registration/password_reset_email.html
(email body template):
Someone asked for password reset for email {{ email }}. Follow the link below:
{{ protocol}}://{{ domain }}{% url 'password_reset_confirm' uidb36=uid token=token %}
The same template context is used for subject template. Subject must be single line plain text string.
password_reset_done
(request[, template_name])¶The page shown after a user has been emailed a link to reset their
password. This view is called by default if the password_reset()
view
doesn’t have an explicit post_reset_redirect
URL set.
URL name: password_reset_done
Optional arguments:
template_name
: The full name of a template to use.
Defaults to registration/password_reset_done.html
if not
supplied.password_reset_confirm
(request[, uidb36, token, template_name, token_generator, set_password_form, post_reset_redirect])¶Presents a form for entering a new password.
URL name: password_reset_confirm
Optional arguments:
uidb36
: The user’s id encoded in base 36. Defaults to None
.token
: Token to check that the password is valid. Defaults to
None
.template_name
: The full name of a template to display the confirm
password view. Default value is registration/password_reset_confirm.html
.token_generator
: Instance of the class to check the password. This
will default to default_token_generator
, it’s an instance of
django.contrib.auth.tokens.PasswordResetTokenGenerator
.set_password_form
: Form that will be used to set the password.
Defaults to SetPasswordForm
post_reset_redirect
: URL to redirect after the password reset
done. Defaults to None
.Template context:
form
: The form (see set_password_form
above) for setting the
new user’s password.validlink
: Boolean, True if the link (combination of uidb36 and
token) is valid or unused yet.password_reset_complete
(request[, template_name])¶Presents a view which informs the user that the password has been successfully changed.
URL name: password_reset_complete
Optional arguments:
template_name
: The full name of a template to display the view.
Defaults to registration/password_reset_complete.html
.redirect_to_login
(next[, login_url, redirect_field_name])¶Redirects to the login page, and then back to another URL after a successful login.
Required arguments:
next
: The URL to redirect to after a successful login.Optional arguments:
login_url
: The URL of the login page to redirect to.
Defaults to settings.LOGIN_URL
if not supplied.redirect_field_name
: The name of a GET
field containing the
URL to redirect to after log out. Overrides next
if the given
GET
parameter is passed.If you don’t want to use the built-in views, but want the convenience of not
having to write forms for this functionality, the authentication system
provides several built-in forms located in django.contrib.auth.forms
:
Note
The built-in authentication forms make certain assumptions about the user model that they are working with. If you’re using a custom User model, it may be necessary to define your own forms for the authentication system. For more information, refer to the documentation about using the built-in authentication forms with custom user models.
AdminPasswordChangeForm
¶A form used in the admin interface to change a user’s password.
AuthenticationForm
¶A form for logging a user in.
PasswordChangeForm
¶A form for allowing a user to change their password.
PasswordResetForm
¶A form for generating and emailing a one-time use link to reset a user’s password.
SetPasswordForm
¶A form that lets a user change his/her password without entering the old password.
UserChangeForm
¶A form used in the admin interface to change a user’s information and permissions.
UserCreationForm
¶A form for creating a new user.
The currently logged-in user and his/her permissions are made available in the
template context when you use
RequestContext
.
Technicality
Technically, these variables are only made available in the template context
if you use RequestContext
and your
TEMPLATE_CONTEXT_PROCESSORS
setting contains
"django.contrib.auth.context_processors.auth"
, which is default. For
more, see the RequestContext docs.
When rendering a template RequestContext
, the
currently logged-in user, either a User
instance or an AnonymousUser
instance, is
stored in the template variable {{ user }}
:
{% if user.is_authenticated %}
<p>Welcome, {{ user.username }}. Thanks for logging in.</p>
{% else %}
<p>Welcome, new user. Please log in.</p>
{% endif %}
This template context variable is not available if a RequestContext
is not
being used.
The currently logged-in user’s permissions are stored in the template variable
{{ perms }}
. This is an instance of
django.contrib.auth.context_processors.PermWrapper
, which is a
template-friendly proxy of permissions.
In the {{ perms }}
object, single-attribute lookup is a proxy to
User.has_module_perms
.
This example would display True
if the logged-in user had any permissions
in the foo
app:
{{ perms.foo }}
Two-level-attribute lookup is a proxy to
User.has_perm
. This example
would display True
if the logged-in user had the permission
foo.can_vote
:
{{ perms.foo.can_vote }}
Thus, you can check permissions in template {% if %}
statements:
{% if perms.foo %}
<p>You have permission to do something in the foo app.</p>
{% if perms.foo.can_vote %}
<p>You can vote!</p>
{% endif %}
{% if perms.foo.can_drive %}
<p>You can drive!</p>
{% endif %}
{% else %}
<p>You don't have permission to do anything in the foo app.</p>
{% endif %}
It is possible to also look permissions up by {% if in %}
statements.
For example:
{% if 'foo' in perms %}
{% if 'foo.can_vote' in perms %}
<p>In lookup works, too.</p>
{% endif %}
{% endif %}
When you have both django.contrib.admin
and django.contrib.auth
installed, the admin provides a convenient way to view and manage users,
groups, and permissions. Users can be created and deleted like any Django
model. Groups can be created, and permissions can be assigned to users or
groups. A log of user edits to models made within the admin is also stored and
displayed.
You should see a link to “Users” in the “Auth” section of the main admin index page. The “Add user” admin page is different than standard admin pages in that it requires you to choose a username and password before allowing you to edit the rest of the user’s fields.
Also note: if you want a user account to be able to create users using the Django admin site, you’ll need to give them permission to add users and change users (i.e., the “Add user” and “Change user” permissions). If an account has permission to add users but not to change them, that account won’t be able to add users. Why? Because if you have permission to add users, you have the power to create superusers, which can then, in turn, change other users. So Django requires add and change permissions as a slight security measure.
User passwords are not displayed in the admin (nor stored in the database), but the password storage details are displayed. Included in the display of this information is a link to a password change form that allows admins to change user passwords.
Oct 01, 2017