# ------------------------------------
# Copyright (c) Microsoft Corporation.
# Licensed under the MIT License.
# ------------------------------------
from typing import TYPE_CHECKING
from ... import CredentialUnavailableError
from ..._constants import DEVELOPER_SIGN_ON_CLIENT_ID
from ..._internal.shared_token_cache import NO_TOKEN, SharedTokenCacheBase
from .._internal import AsyncContextManager
from .._internal.aad_client import AadClient
from .._internal.decorators import log_get_token_async
if TYPE_CHECKING:
from typing import Any
from azure.core.credentials import AccessToken
from ..._internal.aad_client import AadClientBase
[docs]class SharedTokenCacheCredential(SharedTokenCacheBase, AsyncContextManager):
"""Authenticates using tokens in the local cache shared between Microsoft applications.
:param str username:
Username (typically an email address) of the user to authenticate as. This is required because the local cache
may contain tokens for multiple identities.
:keyword str authority: Authority of an Azure Active Directory endpoint, for example 'login.microsoftonline.com',
the authority for Azure Public Cloud (which is the default). :class:`~azure.identity.AzureAuthorityHosts`
defines authorities for other clouds.
:keyword str tenant_id: an Azure Active Directory tenant ID. Used to select an account when the cache contains
tokens for multiple identities.
:keyword cache_persistence_options: configuration for persistent token caching. If not provided, the credential
will use the persistent cache shared by Microsoft development applications
:paramtype cache_persistence_options: ~azure.identity.TokenCachePersistenceOptions
"""
async def __aenter__(self):
if self._client:
await self._client.__aenter__()
return self
[docs] async def close(self):
"""Close the credential's transport session."""
if self._client:
await self._client.__aexit__()
[docs] @log_get_token_async
async def get_token(self, *scopes: str, **kwargs: "Any") -> "AccessToken": # pylint:disable=unused-argument
"""Get an access token for `scopes` from the shared cache.
If no access token is cached, attempt to acquire one using a cached refresh token.
This method is called automatically by Azure SDK clients.
:param str scopes: desired scopes for the access token. This method requires at least one scope.
:rtype: :class:`azure.core.credentials.AccessToken`
:raises ~azure.identity.CredentialUnavailableError: the cache is unavailable or contains insufficient user
information
:raises ~azure.core.exceptions.ClientAuthenticationError: authentication failed. The error's ``message``
attribute gives a reason. Any error response from Azure Active Directory is available as the error's
``response`` attribute.
"""
if not scopes:
raise ValueError("'get_token' requires at least one scope")
if not self._initialized:
self._initialize()
if not self._client:
raise CredentialUnavailableError(message="Shared token cache unavailable")
account = self._get_account(self._username, self._tenant_id)
token = self._get_cached_access_token(scopes, account)
if token:
return token
# try each refresh token, returning the first access token acquired
for refresh_token in self._get_refresh_tokens(account):
token = await self._client.obtain_token_by_refresh_token(scopes, refresh_token)
return token
raise CredentialUnavailableError(message=NO_TOKEN.format(account.get("username")))
def _get_auth_client(self, **kwargs: "Any") -> "AadClientBase":
return AadClient(client_id=DEVELOPER_SIGN_ON_CLIENT_ID, **kwargs)