# copyright 2003-2010 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb. If not, see <http://www.gnu.org/licenses/>.
"""Security hooks: check permissions to add/delete/update entities according to
the user connected to a session
"""
__docformat__ = "restructuredtext en"
from cubicweb import Unauthorized
from cubicweb.selectors import objectify_selector, lltrace
from cubicweb.server import BEFORE_ADD_RELATIONS, ON_COMMIT_ADD_RELATIONS, hook
def check_entity_attributes(session, entity, editedattrs=None, creation=False):
eid = entity.eid
eschema = entity.e_schema
# ._cw_skip_security_attributes is there to bypass security for attributes
# set by hooks by modifying the entity's dictionnary
dontcheck = entity._cw_skip_security_attributes
if editedattrs is None:
try:
editedattrs = entity.edited_attributes
except AttributeError:
editedattrs = entity # XXX unexpected
for attr in editedattrs:
if attr in dontcheck:
continue
rdef = eschema.rdef(attr)
if rdef.final: # non final relation are checked by other hooks
# add/delete should be equivalent (XXX: unify them into 'update' ?)
if creation and not rdef.permissions.get('update'):
continue
rdef.check_perm(session, 'update', eid=eid)
# don't update dontcheck until everything went fine: see usage in
# after_update_entity, where if we got an Unauthorized at hook time, we will
# retry and commit time
dontcheck |= frozenset(editedattrs)
class _CheckEntityPermissionOp(hook.LateOperation):
def precommit_event(self):
#print 'CheckEntityPermissionOp', self.session.user, self.entity, self.action
session = self.session
for values in session.transaction_data.pop('check_entity_perm_op'):
entity = session.entity_from_eid(values[0])
action = values[1]
entity.cw_check_perm(action)
check_entity_attributes(session, entity, values[2:],
creation=self.creation)
def commit_event(self):
pass
class _CheckRelationPermissionOp(hook.LateOperation):
def precommit_event(self):
session = self.session
for args in session.transaction_data.pop('check_relation_perm_op'):
action, rschema, eidfrom, eidto = args
rdef = rschema.rdef(session.describe(eidfrom)[0],
session.describe(eidto)[0])
rdef.check_perm(session, action, fromeid=eidfrom, toeid=eidto)
def commit_event(self):
pass
@objectify_selector
@lltrace
def write_security_enabled(cls, req, **kwargs):
if req is None or not req.write_security:
return 0
return 1
class SecurityHook(hook.Hook):
__abstract__ = True
category = 'security'
__select__ = hook.Hook.__select__ & write_security_enabled()
class AfterAddEntitySecurityHook(SecurityHook):
__regid__ = 'securityafteraddentity'
events = ('after_add_entity',)
def __call__(self):
hook.set_operation(self._cw, 'check_entity_perm_op',
(self.entity.eid, 'add') + tuple(self.entity.edited_attributes),
_CheckEntityPermissionOp, creation=True)
class AfterUpdateEntitySecurityHook(SecurityHook):
__regid__ = 'securityafterupdateentity'
events = ('after_update_entity',)
def __call__(self):
try:
# check user has permission right now, if not retry at commit time
self.entity.cw_check_perm('update')
check_entity_attributes(self._cw, self.entity)
except Unauthorized:
self.entity._cw_clear_local_perm_cache('update')
# save back editedattrs in case the entity is reedited later in the
# same transaction, which will lead to edited_attributes being
# overwritten
hook.set_operation(self._cw, 'check_entity_perm_op',
(self.entity.eid, 'update') + tuple(self.entity.edited_attributes),
_CheckEntityPermissionOp, creation=False)
class BeforeDelEntitySecurityHook(SecurityHook):
__regid__ = 'securitybeforedelentity'
events = ('before_delete_entity',)
def __call__(self):
self.entity.cw_check_perm('delete')
class BeforeAddRelationSecurityHook(SecurityHook):
__regid__ = 'securitybeforeaddrelation'
events = ('before_add_relation',)
def __call__(self):
if self.rtype in BEFORE_ADD_RELATIONS:
nocheck = self._cw.transaction_data.get('skip-security', ())
if (self.eidfrom, self.rtype, self.eidto) in nocheck:
return
rschema = self._cw.repo.schema[self.rtype]
rdef = rschema.rdef(self._cw.describe(self.eidfrom)[0],
self._cw.describe(self.eidto)[0])
rdef.check_perm(self._cw, 'add', fromeid=self.eidfrom, toeid=self.eidto)
class AfterAddRelationSecurityHook(SecurityHook):
__regid__ = 'securityafteraddrelation'
events = ('after_add_relation',)
def __call__(self):
if not self.rtype in BEFORE_ADD_RELATIONS:
nocheck = self._cw.transaction_data.get('skip-security', ())
if (self.eidfrom, self.rtype, self.eidto) in nocheck:
return
rschema = self._cw.repo.schema[self.rtype]
if self.rtype in ON_COMMIT_ADD_RELATIONS:
hook.set_operation(self._cw, 'check_relation_perm_op',
('add', rschema, self.eidfrom, self.eidto),
_CheckRelationPermissionOp)
else:
rdef = rschema.rdef(self._cw.describe(self.eidfrom)[0],
self._cw.describe(self.eidto)[0])
rdef.check_perm(self._cw, 'add', fromeid=self.eidfrom, toeid=self.eidto)
class BeforeDeleteRelationSecurityHook(SecurityHook):
__regid__ = 'securitybeforedelrelation'
events = ('before_delete_relation',)
def __call__(self):
nocheck = self._cw.transaction_data.get('skip-security', ())
if (self.eidfrom, self.rtype, self.eidto) in nocheck:
return
rschema = self._cw.repo.schema[self.rtype]
rdef = rschema.rdef(self._cw.describe(self.eidfrom)[0],
self._cw.describe(self.eidto)[0])
rdef.check_perm(self._cw, 'delete', fromeid=self.eidfrom, toeid=self.eidto)