django-rest-framework/rest_framework/permissions.py

160 lines
5.0 KiB
Python

"""
Provides a set of pluggable permission policies.
"""
from __future__ import unicode_literals
import inspect
import warnings
SAFE_METHODS = ['GET', 'HEAD', 'OPTIONS']
from rest_framework.compat import oauth2_provider_scope, oauth2_constants
class BasePermission(object):
"""
A base class from which all permission classes should inherit.
"""
def has_permission(self, request, view):
"""
Return `True` if permission is granted, `False` otherwise.
"""
return True
def has_object_permission(self, request, view, obj):
"""
Return `True` if permission is granted, `False` otherwise.
"""
if len(inspect.getargspec(self.has_permission).args) == 4:
warnings.warn('The `obj` argument in `has_permission` is due to be deprecated. '
'Use `has_object_permission()` instead for object permissions.',
PendingDeprecationWarning, stacklevel=2)
return self.has_permission(request, view, obj)
return True
class AllowAny(BasePermission):
"""
Allow any access.
This isn't strictly required, since you could use an empty
permission_classes list, but it's useful because it makes the intention
more explicit.
"""
def has_permission(self, request, view):
return True
class IsAuthenticated(BasePermission):
"""
Allows access only to authenticated users.
"""
def has_permission(self, request, view):
if request.user and request.user.is_authenticated():
return True
return False
class IsAdminUser(BasePermission):
"""
Allows access only to admin users.
"""
def has_permission(self, request, view):
if request.user and request.user.is_staff:
return True
return False
class IsAuthenticatedOrReadOnly(BasePermission):
"""
The request is authenticated as a user, or is a read-only request.
"""
def has_permission(self, request, view):
if (request.method in SAFE_METHODS or
request.user and
request.user.is_authenticated()):
return True
return False
class DjangoModelPermissions(BasePermission):
"""
The request is authenticated using `django.contrib.auth` permissions.
See: https://docs.djangoproject.com/en/dev/topics/auth/#permissions
It ensures that the user is authenticated, and has the appropriate
`add`/`change`/`delete` permissions on the model.
This permission will only be applied against view classes that
provide a `.model` attribute, such as the generic class-based views.
"""
# Map methods into required permission codes.
# Override this if you need to also provide 'view' permissions,
# or if you want to provide custom permission codes.
perms_map = {
'GET': [],
'OPTIONS': [],
'HEAD': [],
'POST': ['%(app_label)s.add_%(model_name)s'],
'PUT': ['%(app_label)s.change_%(model_name)s'],
'PATCH': ['%(app_label)s.change_%(model_name)s'],
'DELETE': ['%(app_label)s.delete_%(model_name)s'],
}
authenticated_users_only = True
def get_required_permissions(self, method, model_cls):
"""
Given a model and an HTTP method, return the list of permission
codes that the user is required to have.
"""
kwargs = {
'app_label': model_cls._meta.app_label,
'model_name': model_cls._meta.module_name
}
return [perm % kwargs for perm in self.perms_map[method]]
def has_permission(self, request, view):
model_cls = getattr(view, 'model', None)
queryset = getattr(view, 'queryset', None)
if model_cls is None and queryset is not None:
model_cls = queryset.model
assert model_cls, ('Cannot apply DjangoModelPermissions on a view that'
' does not have `.model` or `.queryset` property.')
perms = self.get_required_permissions(request.method, model_cls)
if (request.user and
(request.user.is_authenticated() or not self.authenticated_users_only) and
request.user.has_perms(perms)):
return True
return False
class TokenHasReadWriteScope(BasePermission):
"""
The request is authenticated as a user and the token used has the right scope
"""
def has_permission(self, request, view):
token = request.auth
read_only = request.method in SAFE_METHODS
if not token:
return False
if hasattr(token, 'resource'): # OAuth 1
return read_only or not request.auth.resource.is_readonly
elif hasattr(token, 'scope'): # OAuth 2
required = oauth2_constants.READ if read_only else oauth2_constants.WRITE
return oauth2_provider_scope.check(required, request.auth.scope)
assert False, ('TokenHasReadWriteScope requires either the'
'`OAuthAuthentication` or `OAuth2Authentication` authentication '
'class to be used.')