Authentication / Authorization
Authentication & authorization make up the components needed to verify who a certain user is and to validate their access to the API and what they can do with it.
Authentication answers the question "Who is this person?" This usually involves requiring credentials, such as an API key or username/password or oAuth tokens.
Authorization answers the question "Is permission granted for this user to take this action?" This usually involves checking permissions such as Create/Read/Update/Delete access, or putting limits on what data the user can access.
Using these classes is simple. Simply provide them (or your own class) as a Meta option to the Resource in question. For example:
from django.contrib.auth.models import User from tastypie.authentication import BasicAuthentication from tastypie.authorization import DjangoAuthorization from tastypie.resources import ModelResource class UserResource(ModelResource): class Meta: queryset = User.objects.all() resource_name = 'auth/user' excludes = ['email', 'password', 'is_superuser'] # Add it here. authentication = BasicAuthentication() authorization = DjangoAuthorization()
Tastypie ships with the following Authentication classes:
The no-op authentication option, the client is always allowed through. Very useful for development and read-only APIs.
This authentication scheme uses HTTP Basic Auth to check a user's credentials. The username is their django.contrib.auth.models.User username (assuming it is present) and their password should also correspond to that entry.
If you're using Apache & mod_wsgi, you will need to enable WSGIPassAuthorization On. See this post for details.
As an alternative to requiring sensitive data like a password, the ApiKeyAuthentication allows you to collect just username & a machine-generated api key. Tastypie ships with a special Model just for this purpose, so you'll need to ensure tastypie is in INSTALLED_APPS.
To use this mechanism, the end user can either specify an Authorization header or pass the username/api_key combination as GET/POST parameters. Examples:
# As a header # Format is ``Authorization: ApiKey <username>:<api_key> Authorization: ApiKey daniel:204db7bcfafb2deb7506b89eb3b9b715b09905c8 # As GET params http://127.0.0.1:8000/api/v1/entries/?username=daniel&api_key=204db7bcfafb2deb7506b89eb3b9b715b09905c8
Tastypie includes a signal function you can use to auto-create ApiKey objects. Hooking it up looks like:
from django.contrib.auth.models import User from django.db import models from tastypie.models import create_api_key models.signals.post_save.connect(create_api_key, sender=User)
If you're using Apache & mod_wsgi, you will need to enable WSGIPassAuthorization On, otherwise mod_wsgi strips out the Authorization header. See this post for details (even though it only mentions Basic auth).
It requires that the user has logged in & has an active session. They also must have a valid CSRF token.
This authentication scheme uses HTTP Digest Auth to check a user's credentials. The username is their django.contrib.auth.models.User username (assuming it is present) and their password should be their machine-generated api key. As with ApiKeyAuthentication, tastypie should be included in INSTALLED_APPS.
If you're using Apache & mod_wsgi, you will need to enable WSGIPassAuthorization On. See this post for details (even though it only mentions Basic auth).
Handles OAuth, which checks a user's credentials against a separate service. Currently verifies against OAuth 1.0a services.
This does NOT provide OAuth authentication in your API, strictly consumption.
If you're used to in-browser OAuth flow (click a "Sign In" button, get redirected, login on remote service, get redirected back), this isn't the same. Most prominently, expecting that would cause API clients to have to use tools like mechanize to fill in forms, which would be difficult.
This authentication expects that you're already followed some sort of OAuth flow & that the credentials (Nonce/token/etc) are simply being passed to it. It merely checks that the credentials are valid. No requests are made to remote services as part of this authentication class.
This authentication class actually wraps any number of other authentication classes, attempting each until successfully authenticating. For example:
from django.contrib.auth.models import User from tastypie.authentication import BasicAuthentication, ApiKeyAuthentication, MultiAuthentication from tastypie.authorization import DjangoAuthorization from tastypie.resources import ModelResource class UserResource(ModelResource): class Meta: queryset = User.objects.all() resource_name = 'auth/user' excludes = ['email', 'password', 'is_superuser'] authentication = MultiAuthentication(BasicAuthentication(), ApiKeyAuthentication()) authorization = DjangoAuthorization()
In the case of an authentication returning a customized HttpUnauthorized, MultiAuthentication defaults to the first returned one. Authentication schemes that need to control the response, such as the included BasicAuthentication and DigestAuthentication, should be placed first.
Tastypie ships with the following Authorization classes:
The no-op authorization option, no permissions checks are performed.
This is a potentially dangerous option, as it means ANY recognized user can modify ANY data they encounter in the API. Be careful who you trust.
This authorization class only permits reading data, regardless of what the Resource might think is allowed. This is the default Authorization class and the safe option.
The most advanced form of authorization, this checks the permission a user has granted to them (via django.contrib.auth.models.Permission). In conjunction with the admin, this is a very effective means of control.
Implementing Your Own Authentication/Authorization
Implementing your own Authentication/Authorization classes is a simple process. Authentication has two methods to override (one of which is optional but recommended to be customized) and Authorization has just one required method and one optional method:
from tastypie.authentication import Authentication from tastypie.authorization import Authorization class SillyAuthentication(Authentication): def is_authenticated(self, request, **kwargs): if 'daniel' in request.user.username: return True return False # Optional but recommended def get_identifier(self, request): return request.user.username class SillyAuthorization(Authorization): def is_authorized(self, request, object=None): if request.user.date_joined.year == 2010: return True else: return False # Optional but useful for advanced limiting, such as per user. def apply_limits(self, request, object_list): if request and hasattr(request, 'user'): return object_list.filter(author__username=request.user.username) return object_list.none()
Under this scheme, only users with 'daniel' in their username will be allowed in, and only those who joined the site in 2010 will be allowed to affect data.
If the optional apply_limits method is included, each user that fits the above criteria will only be able to access their own records.