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