# ------------------------------------
# Copyright (c) Microsoft Corporation.
# Licensed under the MIT License.
# ------------------------------------
from typing import Any, Optional
from azure.core.credentials import AccessToken
from ..._internal.aad_client import AadClientBase
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
[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 a Microsoft Entra 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: a Microsoft Entra 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) -> "SharedTokenCacheCredential":
if self._client:
await self._client.__aenter__() # type: ignore
return self
[docs] async def close(self) -> None:
"""Close the credential's transport session."""
if self._client:
await self._client.__aexit__() # type: ignore
[docs] @log_get_token_async
async def get_token(
self,
*scopes: str,
claims: Optional[str] = None,
tenant_id: Optional[str] = None,
enable_cae: bool = False,
**kwargs: Any
) -> AccessToken:
"""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.
For more information about scopes, see
https://learn.microsoft.com/entra/identity-platform/scopes-oidc.
:keyword str claims: additional claims required in the token, such as those returned in a resource provider's
claims challenge following an authorization failure.
:keyword str tenant_id: optional tenant to include in the token request.
:keyword bool enable_cae: indicates whether to enable Continuous Access Evaluation (CAE) for the requested
token. Defaults to False.
:return: An access token with the desired scopes.
:rtype: ~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 Microsoft Entra ID is available as the error's
``response`` attribute.
"""
if not scopes:
raise ValueError("'get_token' requires at least one scope")
if not self._client_initialized:
self._initialize_client()
is_cae = enable_cae
token_cache = self._cae_cache if is_cae else self._cache
# Try to load the cache if it is None.
if not token_cache:
token_cache = self._initialize_cache(is_cae=is_cae)
# If the cache is still None, raise an error.
if not token_cache:
raise CredentialUnavailableError(message="Shared token cache unavailable")
account = self._get_account(self._username, self._tenant_id, is_cae=is_cae)
token = self._get_cached_access_token(scopes, account, is_cae=is_cae)
if token:
return token
# try each refresh token, returning the first access token acquired
for refresh_token in self._get_refresh_tokens(account, is_cae=is_cae):
token = await self._client.obtain_token_by_refresh_token(
scopes, refresh_token, claims=claims, tenant_id=tenant_id, **kwargs
)
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)