Source code for pyramid.security

from zope.interface import providedBy

from pyramid.interfaces import (
    IAuthenticationPolicy,
    IAuthorizationPolicy,
    ISecuredView,
    IView,
    IViewClassifier,
)

from pyramid.threadlocal import get_current_registry

Everyone = 'system.Everyone'
Authenticated = 'system.Authenticated'
Allow = 'Allow'
Deny = 'Deny'


class AllPermissionsList(object):
    """ Stand in 'permission list' to represent all permissions """

    def __iter__(self):
        return iter(())

    def __contains__(self, other):
        return True

    def __eq__(self, other):
        return isinstance(other, self.__class__)


ALL_PERMISSIONS = AllPermissionsList()
DENY_ALL = (Deny, Everyone, ALL_PERMISSIONS)

NO_PERMISSION_REQUIRED = '__no_permission_required__'


def _get_registry(request):
    try:
        reg = request.registry
    except AttributeError:
        reg = get_current_registry()  # b/c
    return reg


def _get_authentication_policy(request):
    registry = _get_registry(request)
    return registry.queryUtility(IAuthenticationPolicy)


[docs]def remember(request, userid, **kw): """ Returns a sequence of header tuples (e.g. ``[('Set-Cookie', 'foo=abc')]``) on this request's response. These headers are suitable for 'remembering' a set of credentials implied by the data passed as ``userid`` and ``*kw`` using the current :term:`authentication policy`. Common usage might look like so within the body of a view function (``response`` is assumed to be a :term:`WebOb` -style :term:`response` object computed previously by the view code): .. code-block:: python from pyramid.security import remember headers = remember(request, 'chrism', password='123', max_age='86400') response = request.response response.headerlist.extend(headers) return response If no :term:`authentication policy` is in use, this function will always return an empty sequence. If used, the composition and meaning of ``**kw`` must be agreed upon by the calling code and the effective authentication policy. .. versionchanged:: 1.6 Deprecated the ``principal`` argument in favor of ``userid`` to clarify its relationship to the authentication policy. .. versionchanged:: 1.10 Removed the deprecated ``principal`` argument. """ policy = _get_authentication_policy(request) if policy is None: return [] return policy.remember(request, userid, **kw)
[docs]def forget(request): """ Return a sequence of header tuples (e.g. ``[('Set-Cookie', 'foo=abc')]``) suitable for 'forgetting' the set of credentials possessed by the currently authenticated user. A common usage might look like so within the body of a view function (``response`` is assumed to be an :term:`WebOb` -style :term:`response` object computed previously by the view code): .. code-block:: python from pyramid.security import forget headers = forget(request) response.headerlist.extend(headers) return response If no :term:`authentication policy` is in use, this function will always return an empty sequence. """ policy = _get_authentication_policy(request) if policy is None: return [] return policy.forget(request)
[docs]def principals_allowed_by_permission(context, permission): """ Provided a ``context`` (a resource object), and a ``permission`` string, if an :term:`authorization policy` is in effect, return a sequence of :term:`principal` ids that possess the permission in the ``context``. If no authorization policy is in effect, this will return a sequence with the single value :mod:`pyramid.security.Everyone` (the special principal identifier representing all principals). .. note:: Even if an :term:`authorization policy` is in effect, some (exotic) authorization policies may not implement the required machinery for this function; those will cause a :exc:`NotImplementedError` exception to be raised when this function is invoked. """ reg = get_current_registry() policy = reg.queryUtility(IAuthorizationPolicy) if policy is None: return [Everyone] return policy.principals_allowed_by_permission(context, permission)
[docs]def view_execution_permitted(context, request, name=''): """ If the view specified by ``context`` and ``name`` is protected by a :term:`permission`, check the permission associated with the view using the effective authentication/authorization policies and the ``request``. Return a boolean result. If no :term:`authorization policy` is in effect, or if the view is not protected by a permission, return ``True``. If no view can view found, an exception will be raised. .. versionchanged:: 1.4a4 An exception is raised if no view is found. """ reg = _get_registry(request) provides = [IViewClassifier] + [providedBy(x) for x in (request, context)] # XXX not sure what to do here about using _find_views or analogue; # for now let's just keep it as-is view = reg.adapters.lookup(provides, ISecuredView, name=name) if view is None: view = reg.adapters.lookup(provides, IView, name=name) if view is None: raise TypeError( 'No registered view satisfies the constraints. ' 'It would not make sense to claim that this view ' '"is" or "is not" permitted.' ) return Allowed( 'Allowed: view name %r in context %r (no permission defined)' % (name, context) ) return view.__permitted__(context, request)
class PermitsResult(int): def __new__(cls, s, *args): """ Create a new instance. :param fmt: A format string explaining the reason for denial. :param args: Arguments are stored and used with the format string to generate the ``msg``. """ inst = int.__new__(cls, cls.boolval) inst.s = s inst.args = args return inst @property def msg(self): """ A string indicating why the result was generated.""" return self.s % self.args def __str__(self): return self.msg def __repr__(self): return '<%s instance at %s with msg %r>' % ( self.__class__.__name__, id(self), self.msg, )
[docs]class Denied(PermitsResult): """ An instance of ``Denied`` is returned when a security-related API or other :app:`Pyramid` code denies an action unrelated to an ACL check. It evaluates equal to all boolean false types. It has an attribute named ``msg`` describing the circumstances for the deny. """ boolval = 0
[docs]class Allowed(PermitsResult): """ An instance of ``Allowed`` is returned when a security-related API or other :app:`Pyramid` code allows an action unrelated to an ACL check. It evaluates equal to all boolean true types. It has an attribute named ``msg`` describing the circumstances for the allow. """ boolval = 1
class ACLPermitsResult(PermitsResult): def __new__(cls, ace, acl, permission, principals, context): """ Create a new instance. :param ace: The :term:`ACE` that matched, triggering the result. :param acl: The :term:`ACL` containing ``ace``. :param permission: The required :term:`permission`. :param principals: The list of :term:`principals <principal>` provided. :param context: The :term:`context` providing the :term:`lineage` searched. """ fmt = ( '%s permission %r via ACE %r in ACL %r on context %r for ' 'principals %r' ) inst = PermitsResult.__new__( cls, fmt, cls.__name__, permission, ace, acl, context, principals ) inst.permission = permission inst.ace = ace inst.acl = acl inst.principals = principals inst.context = context return inst
[docs]class ACLDenied(ACLPermitsResult, Denied): """ An instance of ``ACLDenied`` is a specialization of :class:`pyramid.security.Denied` that represents that a security check made explicitly against ACL was denied. It evaluates equal to all boolean false types. It also has the following attributes: ``acl``, ``ace``, ``permission``, ``principals``, and ``context``. These attributes indicate the security values involved in the request. Its ``__str__`` method prints a summary of these attributes for debugging purposes. The same summary is available as the ``msg`` attribute. """
[docs]class ACLAllowed(ACLPermitsResult, Allowed): """ An instance of ``ACLAllowed`` is a specialization of :class:`pyramid.security.Allowed` that represents that a security check made explicitly against ACL was allowed. It evaluates equal to all boolean true types. It also has the following attributes: ``acl``, ``ace``, ``permission``, ``principals``, and ``context``. These attributes indicate the security values involved in the request. Its ``__str__`` method prints a summary of these attributes for debugging purposes. The same summary is available as the ``msg`` attribute. """
class AuthenticationAPIMixin(object): @property def authenticated_userid(self): """ Return the userid of the currently authenticated user or ``None`` if there is no :term:`authentication policy` in effect or there is no currently authenticated user. .. versionadded:: 1.5 """ policy = _get_authentication_policy(self) if policy is None: return None return policy.authenticated_userid(self) @property def unauthenticated_userid(self): """ Return an object which represents the *claimed* (not verified) user id of the credentials present in the request. ``None`` if there is no :term:`authentication policy` in effect or there is no user data associated with the current request. This differs from :attr:`~pyramid.request.Request.authenticated_userid`, because the effective authentication policy will not ensure that a record associated with the userid exists in persistent storage. .. versionadded:: 1.5 """ policy = _get_authentication_policy(self) if policy is None: return None return policy.unauthenticated_userid(self) @property def effective_principals(self): """ Return the list of 'effective' :term:`principal` identifiers for the ``request``. If no :term:`authentication policy` is in effect, this will return a one-element list containing the :data:`pyramid.security.Everyone` principal. .. versionadded:: 1.5 """ policy = _get_authentication_policy(self) if policy is None: return [Everyone] return policy.effective_principals(self) class AuthorizationAPIMixin(object): def has_permission(self, permission, context=None): """ Given a permission and an optional context, returns an instance of :data:`pyramid.security.Allowed` if the permission is granted to this request with the provided context, or the context already associated with the request. Otherwise, returns an instance of :data:`pyramid.security.Denied`. This method delegates to the current authentication and authorization policies. Returns :data:`pyramid.security.Allowed` unconditionally if no authentication policy has been registered for this request. If ``context`` is not supplied or is supplied as ``None``, the context used is the ``request.context`` attribute. :param permission: Does this request have the given permission? :type permission: str :param context: A resource object or ``None`` :type context: object :returns: Either :class:`pyramid.security.Allowed` or :class:`pyramid.security.Denied`. .. versionadded:: 1.5 """ if context is None: context = self.context reg = _get_registry(self) authn_policy = reg.queryUtility(IAuthenticationPolicy) if authn_policy is None: return Allowed('No authentication policy in use.') authz_policy = reg.queryUtility(IAuthorizationPolicy) if authz_policy is None: raise ValueError( 'Authentication policy registered without ' 'authorization policy' ) # should never happen principals = authn_policy.effective_principals(self) return authz_policy.permits(context, principals, permission)