# ------------------------------------
# Copyright (c) Microsoft Corporation.
# Licensed under the MIT License.
# ------------------------------------
from typing import Any, Optional, TypeVar, cast
from azure.core.credentials import AccessToken, TokenRequestOptions, AccessTokenInfo, SupportsTokenInfo, TokenCredential
from .silent import SilentAuthenticationCredential
from .. import CredentialUnavailableError
from .._constants import DEVELOPER_SIGN_ON_CLIENT_ID
from .._internal import AadClient, AadClientBase
from .._internal.decorators import log_get_token
from .._internal.shared_token_cache import NO_TOKEN, SharedTokenCacheBase
T = TypeVar("T", bound="_SharedTokenCacheCredential")
[docs]
class SharedTokenCacheCredential:
"""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 used when the
local cache contains 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 AuthenticationRecord authentication_record: an authentication record returned by a user credential such as
:class:`DeviceCodeCredential` or :class:`InteractiveBrowserCredential`
: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
"""
def __init__(self, username: Optional[str] = None, **kwargs: Any) -> None:
if "authentication_record" in kwargs:
self._credential: SupportsTokenInfo = SilentAuthenticationCredential(**kwargs)
else:
self._credential = _SharedTokenCacheCredential(username=username, **kwargs)
def __enter__(self) -> "SharedTokenCacheCredential":
self._credential.__enter__() # type: ignore
return self
def __exit__(self, *args: Any) -> None:
self._credential.__exit__(*args) # type: ignore
[docs]
def close(self) -> None:
"""Close the credential's transport session."""
self.__exit__()
[docs]
@log_get_token
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: not used by this credential; any value provided will be ignored.
: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.
"""
return cast(TokenCredential, self._credential).get_token(
*scopes, claims=claims, tenant_id=tenant_id, enable_cae=enable_cae, **kwargs
)
[docs]
@log_get_token
def get_token_info(self, *scopes: str, options: Optional[TokenRequestOptions] = None) -> AccessTokenInfo:
"""Request an access token for `scopes`.
If no access token is cached, attempt to acquire one using a cached refresh token.
This is an alternative to `get_token` to enable certain scenarios that require additional properties
on the token. This method is called automatically by Azure SDK clients.
:param str scopes: desired scope 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 options: A dictionary of options for the token request. Unknown options will be ignored. Optional.
:paramtype options: ~azure.core.credentials.TokenRequestOptions
:rtype: AccessTokenInfo
:return: An AccessTokenInfo instance containing information about the token.
: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.
"""
return cast(SupportsTokenInfo, self._credential).get_token_info(*scopes, options=options)
[docs]
@staticmethod
def supported() -> bool:
"""Whether the shared token cache is supported on the current platform.
:return: True if the shared token cache is supported on the current platform, otherwise False.
:rtype: bool
"""
return SharedTokenCacheBase.supported()
class _SharedTokenCacheCredential(SharedTokenCacheBase):
"""The original SharedTokenCacheCredential, which doesn't use msal.ClientApplication"""
def __enter__(self: T) -> T:
if self._client:
self._client.__enter__() # type: ignore
return self
def __exit__(self, *args):
if self._client:
self._client.__exit__(*args)
def close(self) -> None:
self.__exit__()
def get_token(
self,
*scopes: str,
claims: Optional[str] = None,
tenant_id: Optional[str] = None,
enable_cae: bool = False,
**kwargs: Any,
) -> AccessToken:
options: TokenRequestOptions = {}
if claims:
options["claims"] = claims
if tenant_id:
options["tenant_id"] = tenant_id
options["enable_cae"] = enable_cae
token_info = self._get_token_base(*scopes, options=options, base_method_name="get_token", **kwargs)
return AccessToken(token_info.token, token_info.expires_on)
def get_token_info(self, *scopes: str, options: Optional[TokenRequestOptions] = None) -> AccessTokenInfo:
return self._get_token_base(*scopes, options=options, base_method_name="get_token_info")
def _get_token_base(
self,
*scopes: str,
options: Optional[TokenRequestOptions] = None,
base_method_name: str = "get_token_info",
**kwargs: Any,
) -> AccessTokenInfo:
if not scopes:
raise ValueError(f"'{base_method_name}' requires at least one scope")
if not self._client_initialized:
self._initialize_client()
options = options or {}
claims = options.get("claims")
tenant_id = options.get("tenant_id")
is_cae = options.get("enable_cae", False)
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 = cast(AadClient, self._client).obtain_token_by_refresh_token(
scopes, refresh_token, claims=claims, tenant_id=tenant_id, enable_cae=is_cae, **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)