+
−"""Security hooks: check permissions to add/delete/update entities according to
+
−the user connected to a session
+
−
+
−:organization: Logilab
+
−:copyright: 2001-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
+
−:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
+
−:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
+
−"""
+
−__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):
+
−    eid = entity.eid
+
−    eschema = entity.e_schema
+
−    # .skip_security_attributes is there to bypass security for attributes
+
−    # set by hooks by modifying the entity's dictionnary
+
−    dontcheck = entity.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' ?)
+
−            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
+
−        self.entity.check_perm(self.action)
+
−        check_entity_attributes(self.session, self.entity, self.editedattrs)
+
−
+
−    def commit_event(self):
+
−        pass
+
−
+
−
+
−class _CheckRelationPermissionOp(hook.LateOperation):
+
−    def precommit_event(self):
+
−        rdef = self.rschema.rdef(self.session.describe(self.eidfrom)[0],
+
−                                 self.session.describe(self.eidto)[0])
+
−        rdef.check_perm(self.session, self.action,
+
−                        fromeid=self.eidfrom, toeid=self.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):
+
−        _CheckEntityPermissionOp(self._cw, entity=self.entity,
+
−                                 editedattrs=tuple(self.entity.edited_attributes),
+
−                                 action='add')
+
−
+
−
+
−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.check_perm('update')
+
−            check_entity_attributes(self._cw, self.entity)
+
−        except Unauthorized:
+
−            self.entity.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
+
−            _CheckEntityPermissionOp(self._cw, entity=self.entity,
+
−                                     editedattrs=tuple(self.entity.edited_attributes),
+
−                                     action='update')
+
−
+
−
+
−class BeforeDelEntitySecurityHook(SecurityHook):
+
−    __regid__ = 'securitybeforedelentity'
+
−    events = ('before_delete_entity',)
+
−
+
−    def __call__(self):
+
−        self.entity.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:
+
−                _CheckRelationPermissionOp(self._cw, action='add',
+
−                                           rschema=rschema,
+
−                                           eidfrom=self.eidfrom,
+
−                                           eidto=self.eidto)
+
−            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)
+
−