core/homeassistant/auth/permissions.py

253 lines
7.5 KiB
Python

"""Permissions for Home Assistant."""
from typing import ( # noqa: F401
cast, Any, Callable, Dict, List, Mapping, Set, Tuple, Union)
import voluptuous as vol
from homeassistant.core import State
CategoryType = Union[Mapping[str, 'CategoryType'], bool, None]
PolicyType = Mapping[str, CategoryType]
# Default policy if group has no policy applied.
DEFAULT_POLICY = {
"entities": True
} # type: PolicyType
CAT_ENTITIES = 'entities'
ENTITY_DOMAINS = 'domains'
ENTITY_ENTITY_IDS = 'entity_ids'
VALUES_SCHEMA = vol.Any(True, vol.Schema({
str: True
}))
ENTITY_POLICY_SCHEMA = vol.Any(True, vol.Schema({
vol.Optional(ENTITY_DOMAINS): VALUES_SCHEMA,
vol.Optional(ENTITY_ENTITY_IDS): VALUES_SCHEMA,
}))
POLICY_SCHEMA = vol.Schema({
vol.Optional(CAT_ENTITIES): ENTITY_POLICY_SCHEMA
})
class AbstractPermissions:
"""Default permissions class."""
def check_entity(self, entity_id: str, *keys: str) -> bool:
"""Test if we can access entity."""
raise NotImplementedError
def filter_states(self, states: List[State]) -> List[State]:
"""Filter a list of states for what the user is allowed to see."""
raise NotImplementedError
class PolicyPermissions(AbstractPermissions):
"""Handle permissions."""
def __init__(self, policy: PolicyType) -> None:
"""Initialize the permission class."""
self._policy = policy
self._compiled = {} # type: Dict[str, Callable[..., bool]]
def check_entity(self, entity_id: str, *keys: str) -> bool:
"""Test if we can access entity."""
func = self._policy_func(CAT_ENTITIES, _compile_entities)
return func(entity_id, keys)
def filter_states(self, states: List[State]) -> List[State]:
"""Filter a list of states for what the user is allowed to see."""
func = self._policy_func(CAT_ENTITIES, _compile_entities)
keys = ('read',)
return [entity for entity in states if func(entity.entity_id, keys)]
def _policy_func(self, category: str,
compile_func: Callable[[CategoryType], Callable]) \
-> Callable[..., bool]:
"""Get a policy function."""
func = self._compiled.get(category)
if func:
return func
func = self._compiled[category] = compile_func(
self._policy.get(category))
return func
def __eq__(self, other: Any) -> bool:
"""Equals check."""
# pylint: disable=protected-access
return (isinstance(other, PolicyPermissions) and
other._policy == self._policy)
class _OwnerPermissions(AbstractPermissions):
"""Owner permissions."""
# pylint: disable=no-self-use
def check_entity(self, entity_id: str, *keys: str) -> bool:
"""Test if we can access entity."""
return True
def filter_states(self, states: List[State]) -> List[State]:
"""Filter a list of states for what the user is allowed to see."""
return states
OwnerPermissions = _OwnerPermissions() # pylint: disable=invalid-name
def _compile_entities(policy: CategoryType) \
-> Callable[[str, Tuple[str]], bool]:
"""Compile policy into a function that tests policy."""
# None, Empty Dict, False
if not policy:
def apply_policy_deny_all(entity_id: str, keys: Tuple[str]) -> bool:
"""Decline all."""
return False
return apply_policy_deny_all
if policy is True:
def apply_policy_allow_all(entity_id: str, keys: Tuple[str]) -> bool:
"""Approve all."""
return True
return apply_policy_allow_all
assert isinstance(policy, dict)
domains = policy.get(ENTITY_DOMAINS)
entity_ids = policy.get(ENTITY_ENTITY_IDS)
funcs = [] # type: List[Callable[[str, Tuple[str]], Union[None, bool]]]
# The order of these functions matter. The more precise are at the top.
# If a function returns None, they cannot handle it.
# If a function returns a boolean, that's the result to return.
# Setting entity_ids to a boolean is final decision for permissions
# So return right away.
if isinstance(entity_ids, bool):
def apply_entity_id_policy(entity_id: str, keys: Tuple[str]) -> bool:
"""Test if allowed entity_id."""
return entity_ids # type: ignore
return apply_entity_id_policy
if entity_ids is not None:
def allowed_entity_id(entity_id: str, keys: Tuple[str]) \
-> Union[None, bool]:
"""Test if allowed entity_id."""
return entity_ids.get(entity_id) # type: ignore
funcs.append(allowed_entity_id)
if isinstance(domains, bool):
def allowed_domain(entity_id: str, keys: Tuple[str]) \
-> Union[None, bool]:
"""Test if allowed domain."""
return domains
funcs.append(allowed_domain)
elif domains is not None:
def allowed_domain(entity_id: str, keys: Tuple[str]) \
-> Union[None, bool]:
"""Test if allowed domain."""
domain = entity_id.split(".", 1)[0]
return domains.get(domain) # type: ignore
funcs.append(allowed_domain)
# Can happen if no valid subcategories specified
if not funcs:
def apply_policy_deny_all_2(entity_id: str, keys: Tuple[str]) -> bool:
"""Decline all."""
return False
return apply_policy_deny_all_2
if len(funcs) == 1:
func = funcs[0]
def apply_policy_func(entity_id: str, keys: Tuple[str]) -> bool:
"""Apply a single policy function."""
return func(entity_id, keys) is True
return apply_policy_func
def apply_policy_funcs(entity_id: str, keys: Tuple[str]) -> bool:
"""Apply several policy functions."""
for func in funcs:
result = func(entity_id, keys)
if result is not None:
return result
return False
return apply_policy_funcs
def merge_policies(policies: List[PolicyType]) -> PolicyType:
"""Merge policies."""
new_policy = {} # type: Dict[str, CategoryType]
seen = set() # type: Set[str]
for policy in policies:
for category in policy:
if category in seen:
continue
seen.add(category)
new_policy[category] = _merge_policies([
policy.get(category) for policy in policies])
cast(PolicyType, new_policy)
return new_policy
def _merge_policies(sources: List[CategoryType]) -> CategoryType:
"""Merge a policy."""
# When merging policies, the most permissive wins.
# This means we order it like this:
# True > Dict > None
#
# True: allow everything
# Dict: specify more granular permissions
# None: no opinion
#
# If there are multiple sources with a dict as policy, we recursively
# merge each key in the source.
policy = None # type: CategoryType
seen = set() # type: Set[str]
for source in sources:
if source is None:
continue
# A source that's True will always win. Shortcut return.
if source is True:
return True
assert isinstance(source, dict)
if policy is None:
policy = {}
assert isinstance(policy, dict)
for key in source:
if key in seen:
continue
seen.add(key)
key_sources = []
for src in sources:
if isinstance(src, dict):
key_sources.append(src.get(key))
policy[key] = _merge_policies(key_sources)
return policy