Этот раздел описывает использование аутентификации пользователя в Django с конфигурацией по умолчанию. Эта конфигурация покрывает требования большинства проектов, предоставляет надежный механизм работы с паролями и правами. Для проектов, которые требуют другой механизм авторизации, Django предоставляет возможность настроить механизм авторизации.
Django предоставляет как аутентификацию так и авторизацию пользователей, обычно этот механизм называют системой аутентификации, т.к. эти функции связанны.
Объекты User - основа системы аутентификации. Они представляют пользователей сайта и используются для проверки прав доступа, регистрации пользователей, ассоциации данных с пользователями. Для представления пользователей в системе аутентификации используется только один класс, 'superusers' или 'staff' такие же объекты пользователей, просто с определенными атрибутами.
Основные атрибуты пользователя:
Подробности ищите в полном описании API, этот раздел больше ориентирован на использование аутентификации.
Самый простой способ создать пользователя - использовать метод create_user():
>>> 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()
Если вы используете интерфейс администратора Django, вы можете создать пользователя через UI.
Суперпользователя можно создать с помощью команды createsuperuser:
$ python manage.py createsuperuser --username=joe --email=joe@example.com
Команда попросит ввести пароль. Пользователь будет создан сразу же по завершению команды. Если не указывать --username или the --email, команда попросит ввести их.
Django не хранит пароль в открытом виде, только хеш (смотрите раздел о работе с паролями). По этому не пробуйте менять атрибут непосредственно. По этому пользователь создается через специальную функцию.
Пароль можно сменить несколькими способами:
manage.py changepassword *username* позволяет сменить пароль пользователя через командную строку. Команда требует ввести пароль дважды. Если совпадают, пароль будет изменен. Если не указать имя пользователя, команда попробует найти пользователя с именем раным текущему системному пользователю.
Вы можете изменить пароль программно, используя метод set_password():
>>> from django.contrib.auth.models import User
>>> u = User.objects.get(username='john')
>>> u.set_password('new password')
>>> u.save()
Если вы используете интерфейс администратора Django, вы можете изменить пароль, используя админку.
Django также предоставляет представления и формы, которые можно использовать при создании страниц для смены пароля пользователем.
При смене пароля будут завершены все сессии пользователя, если вы используете SessionAuthenticationMiddleware. Смотрите Session invalidation on password change.
Для аутентификации пользователя по имени и паролю используйте authenticate(). Параметры авторизации передаются как именованные аргументы, по умолчанию это username и password, если пароль и имя пользователя верны, будет возвращен объект User. Если пароль не правильный, authenticate() возвращает None. Например:
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.")
Примечание
Это низкоуровневый API для аутентификации; например, он используется в RemoteUserMiddleware. Если вы не пишете свою систему авторизации, скорее всего вам не понадобится его использовать. Если вам нужно будет ограничить доступ только авторизованным пользователям, используйте декоратор login_required().
Django предоставляет простую систему проверки прав. Она позволяет добавлять права пользователю или группе пользователей.
Эта система используется админкой Django, но вы можете использовать её и в своем коде.
Админка использует проверку прав следующим образом:
При доступе к странице добавления объекта проверяется наличие прав “add” для объектов этого типа.
При доступе к страницам просмотра списка объектов и изменения объекта проверяется наличие прав “change” для объектов этого типа.
При удалении объекта проверяется наличие прав “delete” для объектов этого типа.
Правда доступа можно добавлять не только типу объекта, но и конкретному объекту. Переопределив методы has_add_permission(), has_change_permission() и has_delete_permission() класса ModelAdmin, можно проверять права для конкретного объекта.
User содержит связи многое ко многим с таблицами groups и user_permissions. Объект модели User работает со связанными моделями, как и другие модели Django:
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()
Если добавить приложение django.contrib.auth в настройку INSTALLED_APPS, оно добавит правда доступа по умолчанию - “add”, “change” и “delete” - для каждой модели из установленных приложений.
Эти права доступа создаются при запуске команды manage.py migrate. При первом выполнении migrate, после добавления django.contrib.auth в INSTALLED_APPS, права доступа по умолчанию создаются для всех старых и новых моделей. Для каждой новой модели они добавляются при выполнении manage.py migrate.
Предположим у вас есть приложение с app_label foo и модель Bar. Чтобы проверить права доступа, используйте:
Модель Permission редко используется на прямую.
Модель django.contrib.auth.models.Group предоставляет возможность группировать пользователей, добавляя им набор прав доступа. Пользователь может принадлежать нескольким группам.
Пользователь, добавленный в группу, автоматически получает все права доступа этой группы. Например, если группа Site editors содержит права доступа can_edit_home_page, любой пользователь в этой группе получить это право доступа.
Также группы позволяют группировать пользователей, добавляя метки или допольнительные возможности. Например, вы можете создать группу 'Special users', и написать код, который, например, предоставляет доступ к дополнительному функционалу сайта, или отправлять сообщения только пользователям этой группы.
Кроме добавления своих прав доступа через класс Meta модели, вы также можете создать их напрямую. Например, создадим право доступа can_publish для модели BlogPost в приложении myapp:
from myapp.models import BlogPost
from django.contrib.auth.models import Group, Permission
from django.contrib.contenttypes.models import ContentType
content_type = ContentType.objects.get_for_model(BlogPost)
permission = Permission.objects.create(codename='can_publish',
name='Can Publish Posts',
content_type=content_type)
Теперь его можно добавить объекту User через атрибут user_permissions или к объекту Group через атрибут permissions.
ModelBackend кэширует правда доступа объекта User после первого запроса на их получение. Такой подход удобен для цикла запрос-ответ, т.к. права доступа редко проверяются сразу же после их изменения например, в админке). Если вы изменяете и проверяете права доступа в одном запросе или в тестах, проще всего загрузить объект User из базы данных заново. Например:
from django.contrib.auth.models import Permission, User
from django.shortcuts import get_object_or_404
def user_gains_perms(request, user_id):
user = get_object_or_404(User, pk=user_id)
# any permission check will cache the current set of permissions
user.has_perm('myapp.change_bar')
permission = Permission.objects.get(codename='change_bar')
user.user_permissions.add(permission)
# Checking the cached permission set
user.has_perm('myapp.change_bar') # False
# Request new instance of User
user = get_object_or_404(User, pk=user_id)
# Permission cache is repopulated from the database
user.has_perm('myapp.change_bar') # True
...
Django использует сессию и промежуточный слой для системы аутентификации в объекте запроса.
Этот механизм предоставляет атрибут request.user для каждого запроса, который возвращает текущего пользователя. Если текущий пользователь не авторизован, атрибут содержит экземпляр AnonymousUser, иначе экземпляр User.
Различить их можно с помощью метода is_authenticated():
if request.user.is_authenticated():
# Do something for authenticated users.
else:
# Do something for anonymous users.
Если вы ходите привязать к сессии авторизованного пользователя, используйте функцию login().
Чтобы залогинить пользователя в представлении, используйте функцию login(). Она принимает объект HttpRequest и объект User. login() сохраняет ID пользователя в сессии, используя приложения сессии Django.
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 raised if you try to login a user object retrieved from the database directly.
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')
# ...
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:
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.
Примечание
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.")
# ...
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):
...
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.
If the raise_exception parameter is given, the decorator will raise PermissionDenied, prompting the 403 (HTTP Forbidden) view instead of redirecting to the login page.
The permission_required() decorator can take a list of permissions as well as a single permission.
To apply a permission to a class-based generic view, decorate the View.dispatch method on the class. See Декорирование классов for details. Another approach is to write a mixin that wraps as_view().
Предупреждение
This protection only applies if SessionAuthenticationMiddleware is enabled in MIDDLEWARE_CLASSES. It’s included if settings.py was generated by startproject on Django ≥ 1.7.
If your AUTH_USER_MODEL inherits from AbstractBaseUser or implements its own get_session_auth_hash() method, authenticated sessions will include the hash returned by this function. In the AbstractBaseUser case, this is an HMAC of the password field. If the SessionAuthenticationMiddleware is enabled, Django verifies that the hash sent along with each request matches the one that’s computed server-side. This allows a user to log out all of their sessions by changing their password.
The default password change views included with Django, django.contrib.auth.views.password_change() and the user_change_password view in the django.contrib.auth admin, update the session with the new password hash so that a user changing their own password won’t log themselves out. If you have a custom password change view and wish to have similar behavior, use this function:
This function takes the current request and the updated user object from which the new session hash will be derived and updates the session hash appropriately. Example usage:
from django.contrib.auth import update_session_auth_hash
def password_change(request):
if request.method == 'POST':
form = PasswordChangeForm(user=request.user, data=request.POST)
if form.is_valid():
form.save()
update_session_auth_hash(request, form.user)
else:
...
If you are upgrading an existing site and wish to enable this middleware without requiring all your users to re-login afterward, you should first upgrade to Django 1.7 and run it for a while so that as sessions are naturally recreated as users login, they include the session hash as described above. Once you start running your site with SessionAuthenticationMiddleware, any users who have not logged in and had their session updated with the verification hash will have their existing session invalidated and be required to login.
Примечание
Since get_session_auth_hash() is based on SECRET_KEY, updating your site to use a new secret will invalidate all existing sessions.
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.
URL name: login
See the URL documentation for details on using named URL patterns.
Optional arguments:
Here’s what django.contrib.auth.views.login does:
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:
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).
Logs a user out.
URL name: logout
Optional arguments:
Template context:
Logs a user out, then redirects to the login page.
URL name: No default URL provided
Optional arguments:
Allows a user to change their password.
URL name: password_change
Optional arguments:
Template context:
The page shown after a user has changed their password.
URL name: password_change_done
Optional arguments:
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.
If the email address provided does not exist in the system, this view won’t send an email, but the user won’t receive any error message either. This prevents information leaking to potential attackers. If you want to provide an error message in this case, you can subclass PasswordResetForm and use the password_reset_form argument.
Users flagged with an unusable password (see set_unusable_password() aren’t allowed to request a password reset to prevent misuse when using an external authentication source like LDAP. Note that they won’t receive any error message since this would expose their account’s existence but no mail will be sent either.
Previously, error messages indicated whether a given email was registered.
URL name: password_reset
Optional arguments:
html_email_template_name was added.
Template context:
Email template context:
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' uidb64=uid token=token %}
Reversing password_reset_confirm takes a uidb64 argument instead of uidb36.
The same template context is used for subject template. Subject must be single line plain text string.
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:
Presents a form for entering a new password.
URL name: password_reset_confirm
Optional arguments:
uidb64: The user’s id encoded in base 64. Defaults to None.
The uidb64 parameter was previously base 36 encoded and named uidb36.
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.
current_app: A hint indicating which application contains the current view. See the namespaced URL resolution strategy for more information.
extra_context: A dictionary of context data that will be added to the default context data passed to the template.
Template context:
Presents a view which informs the user that the password has been successfully changed.
URL name: password_reset_complete
Optional arguments:
Redirects to the login page, and then back to another URL after a successful login.
Required arguments:
Optional arguments:
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:
Примечание
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.
A form used in the admin interface to change a user’s password.
Takes the user as the first positional argument.
A form for logging a user in.
Takes request as its first positional argument, which is stored on the form instance for use by sub-classes.
By default, AuthenticationForm rejects users whose is_active flag is set to False. You may override this behavior with a custom policy to determine which users can log in. Do this with a custom form that subclasses AuthenticationForm and overrides the confirm_login_allowed method. This method should raise a ValidationError if the given user may not log in.
For example, to allow all users to log in, regardless of “active” status:
from django.contrib.auth.forms import AuthenticationForm
class AuthenticationFormWithInactiveUsersOkay(AuthenticationForm):
def confirm_login_allowed(self, user):
pass
Or to allow only some active users to log in:
class PickyAuthenticationForm(AuthenticationForm):
def confirm_login_allowed(self, user):
if not user.is_active:
raise forms.ValidationError(
_("This account is inactive."),
code='inactive',
)
if user.username.startswith('b'):
raise forms.ValidationError(
_("Sorry, accounts starting with 'b' aren't welcome here."),
code='no_b_users',
)
A form for allowing a user to change their password.
A form for generating and emailing a one-time use link to reset a user’s password.
A form that lets a user change their password without entering the old password.
A form used in the admin interface to change a user’s information and permissions.
A form for creating a new user.
The currently logged-in user and their 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.
Mar 30, 2016