# Copyright 2014-2015, Tresys Technology, LLC
#
# SPDX-License-Identifier: LGPL-2.1-only
#
import logging
import re
from typing import cast, Iterable, Optional, Pattern, Union
from . import mixins, query
from .descriptors import CriteriaDescriptor, CriteriaSetDescriptor
from .exception import InvalidType, RuleUseError
from .policyrep import AnyRBACRule, RBACRuletype, Role, TypeOrAttr
from .util import match_indirect_regex
class RBACRuleQuery(mixins.MatchObjClass, query.PolicyQuery):
"""
Query the RBAC rules.
Parameter:
policy The policy to query.
Keyword Parameters/Class attributes:
ruletype The list of rule type(s) to match.
source The name of the source role/attribute to match.
source_indirect If true, members of an attribute will be
matched rather than the attribute itself.
source_regex If true, regular expression matching will
be used on the source role/attribute.
Obeys the source_indirect option.
target The name of the target role/attribute to match.
target_indirect If true, members of an attribute will be
matched rather than the attribute itself.
target_regex If true, regular expression matching will
be used on the target role/attribute.
Obeys target_indirect option.
tclass The object class(es) to match.
tclass_regex If true, use a regular expression for
matching the rule's object class.
default The name of the default role to match.
default_regex If true, regular expression matching will
be used on the default role.
"""
ruletype = CriteriaSetDescriptor(enum_class=RBACRuletype)
source = CriteriaDescriptor("source_regex", "lookup_role")
source_regex: bool = False
source_indirect: bool = True
_target: Optional[Union[Pattern, Role, TypeOrAttr]] = None
target_regex: bool = False
target_indirect: bool = True
tclass = CriteriaSetDescriptor("tclass_regex", "lookup_class")
tclass_regex: bool = False
default = CriteriaDescriptor("default_regex", "lookup_role")
default_regex: bool = False
@property
def target(self) -> Optional[Union[Pattern, Role, TypeOrAttr]]:
return self._target
@target.setter
def target(self, value: Optional[Union[str, Role, TypeOrAttr]]) -> None:
if not value:
self._target = None
elif self.target_regex:
self._target = re.compile(value)
else:
try:
self._target = self.policy.lookup_type_or_attr(cast(Union[str, TypeOrAttr], value))
except InvalidType:
self._target = self.policy.lookup_role(cast(Union[str, Role], value))
def __init__(self, policy, **kwargs) -> None:
super(RBACRuleQuery, self).__init__(policy, **kwargs)
self.log = logging.getLogger(__name__)
def results(self) -> Iterable[AnyRBACRule]:
"""Generator which yields all matching RBAC rules."""
self.log.info("Generating RBAC rule results from {0.policy}".format(self))
self.log.debug("Ruletypes: {0.ruletype}".format(self))
self.log.debug("Source: {0.source!r}, indirect: {0.source_indirect}, "
"regex: {0.source_regex}".format(self))
self.log.debug("Target: {0.target!r}, indirect: {0.target_indirect}, "
"regex: {0.target_regex}".format(self))
self._match_object_class_debug(self.log)
self.log.debug("Default: {0.default!r}, regex: {0.default_regex}".format(self))
for rule in self.policy.rbacrules():
#
# Matching on rule type
#
if self.ruletype:
if rule.ruletype not in self.ruletype:
continue
#
# Matching on source role
#
if self.source and not match_indirect_regex(
rule.source,
self.source,
self.source_indirect,
self.source_regex):
continue
#
# Matching on target type (role_transition)/role(allow)
#
if self.target and not match_indirect_regex(
rule.target,
self.target,
self.target_indirect,
self.target_regex):
continue
#
# Matching on object class
#
try:
if not self._match_object_class(rule):
continue
except RuleUseError:
continue
#
# Matching on default role
#
if self.default:
try:
# because default role is always a single
# role, hard-code indirect to True
# so the criteria can be an attribute
if not match_indirect_regex(
rule.default,
self.default,
True,
self.default_regex):
continue
except RuleUseError:
continue
# if we get here, we have matched all available criteria
yield rule
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