django.contrib.auth
¶This document provides API reference material for the components of Django’s authentication system. For more details on the usage of these components or how to customize authentication and authorization see the authentication topic guide.
User
model¶models.
User
¶User
objects have the following
fields:
username
¶Required. 150 characters or fewer. Usernames may contain alphanumeric,
_
, @
, +
, .
and -
characters.
The max_length
should be sufficient for many use cases. If you need
a longer length, please use a custom user model. If you use MySQL with the utf8mb4
encoding (recommended for proper Unicode support), specify at most
max_length=191
because MySQL can only create unique indexes with
191 characters in that case by default.
Usernames and Unicode
Django originally accepted only ASCII letters and numbers in
usernames. Although it wasn’t a deliberate choice, Unicode
characters have always been accepted when using Python 3. Django
1.10 officially added Unicode support in usernames, keeping the
ASCII-only behavior on Python 2, with the option to customize the
behavior using User.username_validator
.
first_name
¶Optional (blank=True
). 30
characters or fewer.
last_name
¶Optional (blank=True
). 150
characters or fewer.
The max_length
increased from 30 to 150 characters.
email
¶Optional (blank=True
). Email
address.
password
¶Required. A hash of, and metadata about, the password. (Django doesn’t store the raw password.) Raw passwords can be arbitrarily long and can contain any character. See the password documentation.
user_permissions
¶Many-to-many relationship to Permission
is_staff
¶Boolean. Designates whether this user can access the admin site.
is_active
¶Boolean. Designates whether this user account should be considered
active. We recommend that you set this flag to False
instead of
deleting accounts; that way, if your applications have any foreign keys
to users, the foreign keys won’t break.
This doesn’t necessarily control whether or not the user can log in.
Authentication backends aren’t required to check for the is_active
flag but the default backend
(ModelBackend
) and the
RemoteUserBackend
do. You can
use AllowAllUsersModelBackend
or AllowAllUsersRemoteUserBackend
if you want to allow inactive users to login. In this case, you’ll also
want to customize the
AuthenticationForm
used by the
LoginView
as it rejects inactive
users. Be aware that the permission-checking methods such as
has_perm()
and the
authentication in the Django admin all return False
for inactive
users.
is_superuser
¶Boolean. Designates that this user has all permissions without explicitly assigning them.
last_login
¶A datetime of the user’s last login.
date_joined
¶A datetime designating when the account was created. Is set to the current date/time by default when the account is created.
models.
User
is_authenticated
¶Read-only attribute which is always True
(as opposed to
AnonymousUser.is_authenticated
which is always False
). This is
a way to tell if the user has been authenticated. This does not imply
any permissions and doesn’t check if the user is active or has a valid
session. Even though normally you will check this attribute on
request.user
to find out whether it has been populated by the
AuthenticationMiddleware
(representing the currently logged-in user), you should know this
attribute is True
for any User
instance.
is_anonymous
¶Read-only attribute which is always False
. This is a way of
differentiating User
and AnonymousUser
objects. Generally, you should prefer using
is_authenticated
to this
attribute.
username_validator
¶Points to a validator instance used to validate usernames. Defaults to
validators.UnicodeUsernameValidator
.
To change the default username validator, you can subclass the User
model and set this attribute to a different validator instance. For
example, to use ASCII usernames:
from django.contrib.auth.models import User
from django.contrib.auth.validators import ASCIIUsernameValidator
class CustomUser(User):
username_validator = ASCIIUsernameValidator()
class Meta:
proxy = True # If no new field is added.
models.
User
get_username
()¶Returns the username for the user. Since the User
model can be
swapped out, you should use this method instead of referencing the
username attribute directly.
get_full_name
()¶Returns the first_name
plus
the last_name
, with a space in
between.
get_short_name
()¶Returns the first_name
.
set_password
(raw_password)¶Sets the user’s password to the given raw string, taking care of the
password hashing. Doesn’t save the
User
object.
When the raw_password
is None
, the password will be set to an
unusable password, as if
set_unusable_password()
were used.
check_password
(raw_password)¶Returns True
if the given raw string is the correct password for
the user. (This takes care of the password hashing in making the
comparison.)
set_unusable_password
()¶Marks the user as having no password set. This isn’t the same as
having a blank string for a password.
check_password()
for this user
will never return True
. Doesn’t save the
User
object.
You may need this if authentication for your application takes place against an existing external source such as an LDAP directory.
has_usable_password
()¶Returns False
if
set_unusable_password()
has
been called for this user.
In older versions, this also returns False
if the password is
None
or an empty string, or if the password uses a hasher
that’s not in the PASSWORD_HASHERS
setting. That
behavior is considered a bug as it prevents users with such
passwords from requesting a password reset.
get_group_permissions
(obj=None)¶Returns a set of permission strings that the user has, through their groups.
If obj
is passed in, only returns the group permissions for
this specific object.
get_all_permissions
(obj=None)¶Returns a set of permission strings that the user has, both through group and user permissions.
If obj
is passed in, only returns the permissions for this
specific object.
has_perm
(perm, obj=None)¶Returns True
if the user has the specified permission, where perm
is in the format "<app label>.<permission codename>"
. (see
documentation on permissions). If the user is
inactive, this method will always return False
.
If obj
is passed in, this method won’t check for a permission for
the model, but for this specific object.
has_perms
(perm_list, obj=None)¶Returns True
if the user has each of the specified permissions,
where each perm is in the format
"<app label>.<permission codename>"
. If the user is inactive,
this method will always return False
.
If obj
is passed in, this method won’t check for permissions for
the model, but for the specific object.
has_module_perms
(package_name)¶Returns True
if the user has any permissions in the given package
(the Django app label). If the user is inactive, this method will
always return False
.
email_user
(subject, message, from_email=None, **kwargs)¶Sends an email to the user. If from_email
is None
, Django uses
the DEFAULT_FROM_EMAIL
. Any **kwargs
are passed to the
underlying send_mail()
call.
models.
UserManager
¶The User
model has a custom manager
that has the following helper methods (in addition to the methods provided
by BaseUserManager
):
create_user
(username, email=None, password=None, **extra_fields)¶Creates, saves and returns a User
.
The username
and
password
are set as given. The
domain portion of email
is
automatically converted to lowercase, and the returned
User
object will have
is_active
set to True
.
If no password is provided,
set_unusable_password()
will
be called.
The extra_fields
keyword arguments are passed through to the
User
’s __init__
method to
allow setting arbitrary fields on a custom user model.
See Creating users for example usage.
create_superuser
(username, email, password, **extra_fields)¶Same as create_user()
, but sets is_staff
and
is_superuser
to True
.
AnonymousUser
object¶models.
AnonymousUser
¶django.contrib.auth.models.AnonymousUser
is a class that
implements the django.contrib.auth.models.User
interface, with
these differences:
None
.username
is always the empty
string.get_username()
always returns
the empty string.is_anonymous
is True
instead of False
.is_authenticated
is
False
instead of True
.is_staff
and
is_superuser
are always
False
.is_active
is always False
.groups
and
user_permissions
are always
empty.set_password()
,
check_password()
,
save()
and
delete()
raise NotImplementedError
.In practice, you probably won’t need to use
AnonymousUser
objects on your own, but
they’re used by Web requests, as explained in the next section.
Permission
model¶models.
Permission
¶Permission
objects have the following
fields:
Permission
objects have the standard
data-access methods like any other Django model.
Group
model¶models.
Group
¶Group
objects have the following fields:
models.
Group
name
¶Required. 80 characters or fewer. Any characters are permitted. Example:
'Awesome Users'
.
permissions
¶Many-to-many field to Permission
:
group.permissions.set([permission_list])
group.permissions.add(permission, permission, ...)
group.permissions.remove(permission, permission, ...)
group.permissions.clear()
validators.
ASCIIUsernameValidator
¶A field validator allowing only ASCII letters and numbers, in addition to
@
, .
, +
, -
, and _
.
validators.
UnicodeUsernameValidator
¶A field validator allowing Unicode characters, in addition to @
, .
,
+
, -
, and _
. The default validator for User.username
.
The auth framework uses the following signals that can be used for notification when a user logs in or out.
user_logged_in
()¶Sent when a user logs in successfully.
Arguments sent with this signal:
sender
request
HttpRequest
instance.user
user_logged_out
()¶Sent when the logout method is called.
sender
None
if the user was not authenticated.request
HttpRequest
instance.user
None
if the
user was not authenticated.user_login_failed
()¶Sent when the user failed to login successfully
sender
credentials
authenticate()
or your own custom
authentication backend. Credentials matching a set of ‘sensitive’ patterns,
(including password) will not be sent in the clear as part of the signal.request
HttpRequest
object, if one was provided to
authenticate()
.This section details the authentication backends that come with Django. For information on how to use them and how to write your own authentication backends, see the Other authentication sources section of the User authentication guide.
The following backends are available in django.contrib.auth.backends
:
ModelBackend
¶This is the default authentication backend used by Django. It authenticates using credentials consisting of a user identifier and password. For Django’s default user model, the user identifier is the username, for custom user models it is the field specified by USERNAME_FIELD (see Customizing Users and authentication).
It also handles the default permissions model as defined for
User
and
PermissionsMixin
.
has_perm()
, get_all_permissions()
, get_user_permissions()
,
and get_group_permissions()
allow an object to be passed as a
parameter for object-specific permissions, but this backend does not
implement them other than returning an empty set of permissions if
obj is not None
.
authenticate
(request, username=None, password=None, **kwargs)¶Tries to authenticate username
with password
by calling
User.check_password
. If no username
is provided, it tries to fetch a username from kwargs
using the
key CustomUser.USERNAME_FIELD
. Returns an
authenticated user or None
.
request
is an HttpRequest
and may be None
if it wasn’t provided to authenticate()
(which passes it on to the backend).
get_user_permissions
(user_obj, obj=None)¶Returns the set of permission strings the user_obj
has from their
own user permissions. Returns an empty set if
is_anonymous
or
is_active
is False
.
get_group_permissions
(user_obj, obj=None)¶Returns the set of permission strings the user_obj
has from the
permissions of the groups they belong. Returns an empty set if
is_anonymous
or
is_active
is False
.
get_all_permissions
(user_obj, obj=None)¶Returns the set of permission strings the user_obj
has, including both
user permissions and group permissions. Returns an empty set if
is_anonymous
or
is_active
is False
.
has_perm
(user_obj, perm, obj=None)¶Uses get_all_permissions()
to check if user_obj
has the
permission string perm
. Returns False
if the user is not
is_active
.
has_module_perms
(user_obj, app_label)¶Returns whether the user_obj
has any permissions on the app
app_label
.
user_can_authenticate
()¶Returns whether the user is allowed to authenticate. To match the
behavior of AuthenticationForm
which prohibits inactive users from logging in
,
this method returns False
for users with is_active=False
. Custom user models that
don’t have an is_active
field are allowed.
AllowAllUsersModelBackend
¶Same as ModelBackend
except that it doesn’t reject inactive users
because user_can_authenticate()
always returns True
.
When using this backend, you’ll likely want to customize the
AuthenticationForm
used by the
LoginView
by overriding the
confirm_login_allowed()
method as it rejects inactive users.
RemoteUserBackend
¶Use this backend to take advantage of external-to-Django-handled
authentication. It authenticates using usernames passed in
request.META['REMOTE_USER']
. See
the Authenticating against REMOTE_USER
documentation.
If you need more control, you can create your own authentication backend that inherits from this class and override these attributes or methods:
create_unknown_user
¶True
or False
. Determines whether or not a user object is
created if not already in the database Defaults to True
.
authenticate
(request, remote_user)¶The username passed as remote_user
is considered trusted. This
method simply returns the user object with the given username, creating
a new user object if create_unknown_user
is
True
.
Returns None
if create_unknown_user
is
False
and a User
object with the given username is not found in
the database.
request
is an HttpRequest
and may be None
if it wasn’t provided to authenticate()
(which passes it on to the backend).
clean_username
(username)¶Performs any cleaning on the username
(e.g. stripping LDAP DN
information) prior to using it to get or create a user object. Returns
the cleaned username.
configure_user
(user)¶Configures a newly created user. This method is called immediately after a new user is created, and can be used to perform custom setup actions, such as setting the user’s groups based on attributes in an LDAP directory. Returns the user object.
user_can_authenticate
()¶Returns whether the user is allowed to authenticate. This method
returns False
for users with is_active=False
. Custom user models that
don’t have an is_active
field are allowed.
AllowAllUsersRemoteUserBackend
¶Same as RemoteUserBackend
except that it doesn’t reject inactive
users because user_can_authenticate
always
returns True
.
get_user
(request)[source]¶Returns the user model instance associated with the given request
’s
session.
It checks if the authentication backend stored in the session is present in
AUTHENTICATION_BACKENDS
. If so, it uses the backend’s
get_user()
method to retrieve the user model instance and then verifies
the session by calling the user model’s
get_session_auth_hash()
method.
Returns an instance of AnonymousUser
if the authentication backend stored in the session is no longer in
AUTHENTICATION_BACKENDS
, if a user isn’t returned by the
backend’s get_user()
method, or if the session auth hash doesn’t
validate.
Dec 24, 2018