authentik/passbook/policies/expression/evaluator.py

72 lines
2.9 KiB
Python

"""passbook expression policy evaluator"""
from typing import List
from django.http import HttpRequest
from structlog import get_logger
from passbook.flows.planner import PLAN_CONTEXT_SSO
from passbook.flows.views import SESSION_KEY_PLAN
from passbook.lib.expression.evaluator import BaseEvaluator
from passbook.lib.utils.http import get_client_ip
from passbook.policies.types import PolicyRequest, PolicyResult
LOGGER = get_logger()
class PolicyEvaluator(BaseEvaluator):
"""Validate and evaluate python-based expressions"""
_messages: List[str]
def __init__(self, policy_name: str):
super().__init__()
self._messages = []
self._context["pb_message"] = self.expr_func_message
self._filename = policy_name
def expr_func_message(self, message: str):
"""Wrapper to append to messages list, which is returned with PolicyResult"""
self._messages.append(message)
def set_policy_request(self, request: PolicyRequest):
"""Update context based on policy request (if http request is given, update that too)"""
# update passbook/policies/expression/templates/policy/expression/form.html
# update docs/policies/expression/index.md
self._context["pb_is_sso_flow"] = request.context.get(PLAN_CONTEXT_SSO, False)
if request.http_request:
self.set_http_request(request.http_request)
self._context["request"] = request
def set_http_request(self, request: HttpRequest):
"""Update context based on http request"""
# update passbook/policies/expression/templates/policy/expression/form.html
# update docs/policies/expression/index.md
self._context["pb_client_ip"] = get_client_ip(request) or "255.255.255.255"
self._context["request"] = request
if SESSION_KEY_PLAN in request.session:
self._context["pb_flow_plan"] = request.session[SESSION_KEY_PLAN]
def evaluate(self, expression_source: str) -> PolicyResult:
"""Parse and evaluate expression. Policy is expected to return a truthy object.
Messages can be added using 'do pb_message()'."""
try:
result = super().evaluate(expression_source)
except (ValueError, SyntaxError) as exc:
return PolicyResult(False, str(exc))
except Exception as exc: # pylint: disable=broad-except
LOGGER.warning("Expression error", exc=exc)
return PolicyResult(False, str(exc))
else:
policy_result = PolicyResult(False)
policy_result.messages = tuple(self._messages)
if result is None:
LOGGER.warning(
"Expression policy returned None",
src=expression_source,
req=self._context,
)
policy_result.passing = False
if result:
policy_result.passing = bool(result)
return policy_result