llama-stack-mirror/llama_stack/distribution/access_control/access_control.py
Gordon Sim 96cd51a0c8 Changes to access rule conditions:
* change from access_attributes to owner on dynamically created resources
 * define simpler string based conditions for more intuitive restriction
2025-06-03 19:51:58 +01:00

109 lines
3.1 KiB
Python

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the terms described in the LICENSE file in
# the root directory of this source tree.
from typing import Any
from llama_stack.distribution.datatypes import User
from .conditions import (
Condition,
ProtectedResource,
parse_conditions,
)
from .datatypes import (
AccessRule,
Action,
Scope,
)
def matches_resource(resource_scope: str, actual_resource: str) -> bool:
if resource_scope == actual_resource:
return True
return resource_scope.endswith("::*") and actual_resource.startswith(resource_scope[:-1])
def matches_scope(
scope: Scope,
action: Action,
resource: str,
user: str | None,
) -> bool:
if scope.resource and not matches_resource(scope.resource, resource):
return False
if scope.principal and scope.principal != user:
return False
return action in scope.actions
def as_list(obj: Any) -> list[Any]:
if isinstance(obj, list):
return obj
return [obj]
def matches_conditions(
conditions: list[Condition],
resource: ProtectedResource,
user: User,
) -> bool:
for condition in conditions:
# must match all conditions
if not condition.matches(resource, user):
return False
return True
def default_policy() -> list[AccessRule]:
# for backwards compatibility, if no rules are provided, assume
# full access subject to previous attribute matching rules
return [
AccessRule(
permit=Scope(actions=list(Action)),
when=["user in owners " + name for name in ["roles", "teams", "projects", "namespaces"]],
),
]
def is_action_allowed(
policy: list[AccessRule],
action: Action,
resource: ProtectedResource,
user: User | None,
) -> bool:
# If user is not set, assume authentication is not enabled
if not user:
return True
if not len(policy):
policy = default_policy()
qualified_resource_id = resource.type + "::" + resource.identifier
for rule in policy:
if rule.forbid and matches_scope(rule.forbid, action, qualified_resource_id, user.principal):
if rule.when:
if matches_conditions(parse_conditions(as_list(rule.when)), resource, user):
return False
elif rule.unless:
if not matches_conditions(parse_conditions(as_list(rule.unless)), resource, user):
return False
else:
return False
elif rule.permit and matches_scope(rule.permit, action, qualified_resource_id, user.principal):
if rule.when:
if matches_conditions(parse_conditions(as_list(rule.when)), resource, user):
return True
elif rule.unless:
if not matches_conditions(parse_conditions(as_list(rule.unless)), resource, user):
return True
else:
return True
# assume access is denied unless we find a rule that permits access
return False
class AccessDeniedError(RuntimeError):
pass