Source code for pyramid.security

from zope.interface import providedBy

from pyramid.interfaces import IAuthenticationPolicy
from pyramid.interfaces import IAuthorizationPolicy
from pyramid.interfaces import ISecuredView
from pyramid.interfaces import 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 ()
    def __contains__(self, other):
        return True
    def __eq__(self, other):
        return isinstance(other, self.__class__)

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

[docs]def has_permission(permission, context, request): """ Provided a permission (a string or unicode object), a context (a :term:`resource` instance) and a request object, return an instance of :data:`pyramid.security.Allowed` if the permission is granted in this context to the user implied by the request. Return an instance of :mod:`pyramid.security.Denied` if this permission is not granted in this context to this user. This function delegates to the current authentication and authorization policies. Return :data:`pyramid.security.Allowed` unconditionally if no authentication policy has been configured in this application.""" try: reg = request.registry except AttributeError: reg = get_current_registry() # b/c 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(request) return authz_policy.permits(context, principals, permission)
[docs]def authenticated_userid(request): """ 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.""" try: reg = request.registry except AttributeError: reg = get_current_registry() # b/c policy = reg.queryUtility(IAuthenticationPolicy) if policy is None: return None return policy.authenticated_userid(request)
[docs]def unauthenticated_userid(request): """ 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 :func:`~pyramid.security.authenticated_userid`, because the effective authentication policy will not ensure that a record associated with the userid exists in persistent storage.""" try: reg = request.registry except AttributeError: reg = get_current_registry() # b/c policy = reg.queryUtility(IAuthenticationPolicy) if policy is None: return None return policy.unauthenticated_userid(request)
[docs]def effective_principals(request): """ Return the list of 'effective' :term:`principal` identifiers for the ``request``. This will include the userid of the currently authenticated user if a user is currently authenticated. If no :term:`authentication policy` is in effect, this will return an empty sequence.""" try: reg = request.registry except AttributeError: reg = get_current_registry() # b/c policy = reg.queryUtility(IAuthenticationPolicy) if policy is None: return [] return policy.effective_principals(request)
[docs]def principals_allowed_by_permission(context, permission): """ Provided a ``context`` (a resource object), and a ``permission`` (a string or unicode object), if a :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``.""" try: reg = request.registry except AttributeError: reg = get_current_registry() # b/c provides = [IViewClassifier] + map(providedBy, (request, context)) view = reg.adapters.lookup(provides, ISecuredView, name=name) if view is None: return Allowed( 'Allowed: view name %r in context %r (no permission defined)' % (name, context)) return view.__permitted__(context, request)
[docs]def remember(request, principal, **kw): """ Return a sequence of header tuples (e.g. ``[('Set-Cookie', 'foo=abc')]``) suitable for 'remembering' a set of credentials implied by the data passed as ``principal`` 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):: from pyramid.security import remember headers = remember(request, 'chrism', password='123', max_age='86400') 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.""" try: reg = request.registry except AttributeError: reg = get_current_registry() # b/c policy = reg.queryUtility(IAuthenticationPolicy) if policy is None: return [] else: return policy.remember(request, principal, **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):: 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.""" try: reg = request.registry except AttributeError: reg = get_current_registry() # b/c policy = reg.queryUtility(IAuthenticationPolicy) if policy is None: return [] else: return policy.forget(request)
class PermitsResult(int): def __new__(cls, s, *args): inst = int.__new__(cls, cls.boolval) inst.s = s inst.args = args return inst @property def msg(self): 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(int): def __new__(cls, ace, acl, permission, principals, context): inst = int.__new__(cls, cls.boolval) inst.permission = permission inst.ace = ace inst.acl = acl inst.principals = principals inst.context = context return inst @property def msg(self): s = ('%s permission %r via ACE %r in ACL %r on context %r for ' 'principals %r') return s % (self.__class__.__name__, self.permission, self.ace, self.acl, self.context, self.principals) 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 ACLDenied(ACLPermitsResult): """ An instance of ``ACLDenied`` represents that a security check made explicitly against ACL was denied. It evaluates equal to all boolean false types. It also has attributes which indicate which acl, ace, permission, principals, and context were 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.""" boolval = 0
[docs]class ACLAllowed(ACLPermitsResult): """ An instance of ``ACLAllowed`` represents that a security check made explicitly against ACL was allowed. It evaluates equal to all boolean true types. It also has attributes which indicate which acl, ace, permission, principals, and context were 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.""" boolval = 1