Refactor ClientSecretCredential to use AadClient

sdk/identity/azure-identity/azure/identity/_credentials/client_secret.py

@@ -2,8 +2,7 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 # ------------------------------------
-from .._authn_client import AuthnClient
-from .._base import ClientSecretCredentialBase
+from .._internal import AadClient, ClientSecretCredentialBase
 
 try:
     from typing import TYPE_CHECKING
@@ -28,12 +27,7 @@ class ClientSecretCredential(ClientSecretCredentialBase):
           defines authorities for other clouds.
     """
 
-    def __init__(self, tenant_id, client_id, client_secret, **kwargs):
-        # type: (str, str, str, **Any) -> None
-        super(ClientSecretCredential, self).__init__(tenant_id, client_id, client_secret, **kwargs)
-        self._client = AuthnClient(tenant=tenant_id, **kwargs)
-
-    def get_token(self, *scopes, **kwargs):  # pylint:disable=unused-argument
+    def get_token(self, *scopes, **kwargs):
         # type: (*str, **Any) -> AccessToken
         """Request an access token for `scopes`.
 
@@ -48,8 +42,10 @@ def get_token(self, *scopes, **kwargs):  # pylint:disable=unused-argument
         if not scopes:
             raise ValueError("'get_token' requires at least one scope")
 
-        token = self._client.get_cached_token(scopes)
+        token = self._client.get_cached_access_token(scopes)
         if not token:
-            data = dict(self._form_data, scope=" ".join(scopes))
-            token = self._client.request_token(scopes, form_data=data)
+            token = self._client.obtain_token_by_client_secret(scopes, self._secret, **kwargs)
         return token
+
+    def _get_auth_client(self, tenant_id, client_id, **kwargs):
+        return AadClient(tenant_id, client_id, **kwargs)

sdk/identity/azure-identity/azure/identity/_internal/__init__.py

@@ -35,6 +35,7 @@ def get_default_authority():
 from .auth_code_redirect_handler import AuthCodeRedirectServer
 from .aadclient_certificate import AadClientCertificate
 from .certificate_credential_base import CertificateCredentialBase
+from .client_secret_credential_base import ClientSecretCredentialBase
 from .exception_wrapper import wrap_exceptions
 from .msal_credentials import ConfidentialClientCredential, InteractiveCredential, PublicClientCredential
 from .msal_transport_adapter import MsalTransportAdapter, MsalTransportResponse
@@ -60,6 +61,7 @@ def _scopes_to_resource(*scopes):
     "AuthCodeRedirectServer",
     "AadClientCertificate",
     "CertificateCredentialBase",
+    "ClientSecretCredentialBase",
     "ConfidentialClientCredential",
     "get_default_authority",
     "InteractiveCredential",

sdk/identity/azure-identity/azure/identity/_internal/aad_client.py

@@ -33,7 +33,7 @@
 
 class AadClient(AadClientBase):
     def obtain_token_by_authorization_code(self, scopes, code, redirect_uri, client_secret=None, **kwargs):
-        # type: (str, str, Sequence[str], Optional[str], **Any) -> AccessToken
+        # type: (Sequence[str], str, str, Optional[str], **Any) -> AccessToken
         request = self._get_auth_code_request(
             scopes=scopes, code=code, redirect_uri=redirect_uri, client_secret=client_secret
         )
@@ -50,8 +50,16 @@ def obtain_token_by_client_certificate(self, scopes, certificate, **kwargs):
         content = ContentDecodePolicy.deserialize_from_http_generics(response.http_response)
         return self._process_response(response=content, scopes=scopes, now=now)
 
+    def obtain_token_by_client_secret(self, scopes, secret, **kwargs):
+        # type: (Sequence[str], str, **Any) -> AccessToken
+        request = self._get_client_secret_request(scopes, secret)
+        now = int(time.time())
+        response = self._pipeline.run(request, stream=False, **kwargs)
+        content = ContentDecodePolicy.deserialize_from_http_generics(response.http_response)
+        return self._process_response(response=content, scopes=scopes, now=now)
+
     def obtain_token_by_refresh_token(self, scopes, refresh_token, **kwargs):
-        # type: (str, Sequence[str], **Any) -> AccessToken
+        # type: (Sequence[str], str, **Any) -> AccessToken
         request = self._get_refresh_token_request(scopes, refresh_token)
         now = int(time.time())
         response = self._pipeline.run(request, stream=False, **kwargs)

sdk/identity/azure-identity/azure/identity/_internal/aad_client_base.py

@@ -71,6 +71,10 @@ def obtain_token_by_authorization_code(self, scopes, code, redirect_uri, client_
     def obtain_token_by_client_certificate(self, scopes, certificate, **kwargs):
         pass
 
+    @abc.abstractmethod
+    def obtain_token_by_client_secret(self, scopes, secret, **kwargs):
+        pass
+
     @abc.abstractmethod
     def obtain_token_by_refresh_token(self, scopes, refresh_token, **kwargs):
         pass
@@ -131,6 +135,19 @@ def _get_client_certificate_request(self, scopes, certificate):
         )
         return request
 
+    def _get_client_secret_request(self, scopes, secret):
+        # type: (Sequence[str], str) -> HttpRequest
+        data = {
+            "client_id": self._client_id,
+            "client_secret": secret,
+            "grant_type": "client_credentials",
+            "scope": " ".join(scopes),
+        }
+        request = HttpRequest(
+            "POST", self._token_endpoint, headers={"Content-Type": "application/x-www-form-urlencoded"}, data=data
+        )
+        return request
+
     def _get_jwt_assertion(self, certificate):
         # type: (AadClientCertificate) -> str
         now = int(time.time())

sdk/identity/azure-identity/azure/identity/_base.py → sdk/identity/azure-identity/azure/identity/_internal/client_secret_credential_base.py

@@ -3,34 +3,33 @@
 # Licensed under the MIT License.
 # ------------------------------------
 import abc
+from typing import TYPE_CHECKING
 
 try:
     ABC = abc.ABC
-except AttributeError:  # Python 2.7, abc exists, but not ABC
+except AttributeError:  # Python 2.7
     ABC = abc.ABCMeta("ABC", (object,), {"__slots__": ()})  # type: ignore
 
-try:
-    from typing import TYPE_CHECKING
-except ImportError:
-    TYPE_CHECKING = False
-
 if TYPE_CHECKING:
-    # pylint:disable=unused-import
-    from typing import Any, Optional, Union
-
+    # pylint:disable=unused-import,ungrouped-imports
+    from typing import Any
 
-class ClientSecretCredentialBase(object):
-    """Sans I/O base for client secret credentials"""
 
-    def __init__(self, tenant_id, client_id, secret, **kwargs):  # pylint:disable=unused-argument
+class ClientSecretCredentialBase(ABC):
+    def __init__(self, tenant_id, client_id, client_secret, **kwargs):
         # type: (str, str, str, **Any) -> None
         if not client_id:
             raise ValueError("client_id should be the id of an Azure Active Directory application")
-        if not secret:
+        if not client_secret:
             raise ValueError("secret should be an Azure Active Directory application's client secret")
         if not tenant_id:
             raise ValueError(
                 "tenant_id should be an Azure Active Directory tenant's id (also called its 'directory id')"
             )
-        self._form_data = {"client_id": client_id, "client_secret": secret, "grant_type": "client_credentials"}
-        super(ClientSecretCredentialBase, self).__init__()
+
+        self._client = self._get_auth_client(tenant_id, client_id, **kwargs)
+        self._secret = client_secret
+
+    @abc.abstractmethod
+    def _get_auth_client(self, tenant_id, client_id, **kwargs):
+        pass

sdk/identity/azure-identity/azure/identity/aio/_credentials/client_secret.py

@@ -5,15 +5,15 @@
 from typing import TYPE_CHECKING
 
 from .base import AsyncCredentialBase
-from .._authn_client import AsyncAuthnClient
-from ..._base import ClientSecretCredentialBase
+from .._internal import AadClient
+from ..._internal import ClientSecretCredentialBase
 
 if TYPE_CHECKING:
     from typing import Any
     from azure.core.credentials import AccessToken
 
 
-class ClientSecretCredential(ClientSecretCredentialBase, AsyncCredentialBase):
+class ClientSecretCredential(AsyncCredentialBase, ClientSecretCredentialBase):
     """Authenticates as a service principal using a client ID and client secret.
 
     :param str tenant_id: ID of the service principal's tenant. Also called its 'directory' ID.
@@ -25,10 +25,6 @@ class ClientSecretCredential(ClientSecretCredentialBase, AsyncCredentialBase):
           defines authorities for other clouds.
     """
 
-    def __init__(self, tenant_id: str, client_id: str, client_secret: str, **kwargs: "Any") -> None:
-        super(ClientSecretCredential, self).__init__(tenant_id, client_id, client_secret, **kwargs)
-        self._client = AsyncAuthnClient(tenant=tenant_id, **kwargs)
-
     async def __aenter__(self):
         await self._client.__aenter__()
         return self
@@ -38,7 +34,7 @@ async def close(self):
 
         await self._client.__aexit__()
 
-    async def get_token(self, *scopes: str, **kwargs: "Any") -> "AccessToken":  # pylint:disable=unused-argument
+    async def get_token(self, *scopes: str, **kwargs: "Any") -> "AccessToken":
         """Asynchronously request an access token for `scopes`.
 
         .. note:: This method is called by Azure SDK clients. It isn't intended for use in application code.
@@ -52,8 +48,10 @@ async def get_token(self, *scopes: str, **kwargs: "Any") -> "AccessToken":  # py
         if not scopes:
             raise ValueError("'get_token' requires at least one scope")
 
-        token = self._client.get_cached_token(scopes)
+        token = self._client.get_cached_access_token(scopes)
         if not token:
-            data = dict(self._form_data, scope=" ".join(scopes))
-            token = await self._client.request_token(scopes, form_data=data)
-        return token  # type: ignore
+            token = await self._client.obtain_token_by_client_secret(scopes, self._secret, **kwargs)
+        return token
+
+    def _get_auth_client(self, tenant_id, client_id, **kwargs):
+        return AadClient(tenant_id, client_id, **kwargs)

sdk/identity/azure-identity/azure/identity/aio/_internal/aad_client.py

@@ -67,6 +67,15 @@ async def obtain_token_by_client_certificate(self, scopes, certificate, **kwargs
         content = ContentDecodePolicy.deserialize_from_http_generics(response.http_response)
         return self._process_response(response=content, scopes=scopes, now=now)
 
+    async def obtain_token_by_client_secret(
+        self, scopes: "Sequence[str]", secret: str, **kwargs: "Any"
+    ) -> "AccessToken":
+        request = self._get_client_secret_request(scopes, secret)
+        now = int(time.time())
+        response = await self._pipeline.run(request, **kwargs)
+        content = ContentDecodePolicy.deserialize_from_http_generics(response.http_response)
+        return self._process_response(response=content, scopes=scopes, now=now)
+
     async def obtain_token_by_refresh_token(
         self, scopes: "Sequence[str]", refresh_token: str, **kwargs: "Any"
     ) -> "AccessToken":

sdk/identity/azure-identity/tests/test_aad_client.py

@@ -126,6 +126,30 @@ def send(request, **_):
     assert transport.send.call_count == 1
 
 
+def test_client_secret():
+    tenant_id = "tenant-id"
+    client_id = "client-id"
+    scope = "scope"
+    secret = "refresh-token"
+    access_token = "***"
+
+    def send(request, **_):
+        assert request.data["client_id"] == client_id
+        assert request.data["client_secret"] == secret
+        assert request.data["grant_type"] == "client_credentials"
+        assert request.data["scope"] == scope
+
+        return mock_response(json_payload={"access_token": access_token, "expires_in": 42})
+
+    transport = Mock(send=Mock(wraps=send))
+
+    client = AadClient(tenant_id, client_id, transport=transport)
+    token = client.obtain_token_by_client_secret(scopes=(scope,), secret=secret)
+
+    assert token.token == access_token
+    assert transport.send.call_count == 1
+
+
 def test_refresh_token():
     tenant_id = "tenant-id"
     client_id = "client-id"

sdk/identity/azure-identity/tests/test_aad_client_async.py

@@ -108,6 +108,30 @@ async def send(request, **_):
     assert transport.send.call_count == 1
 
 
+async def test_client_secret():
+    tenant_id = "tenant-id"
+    client_id = "client-id"
+    scope = "scope"
+    secret = "refresh-token"
+    access_token = "***"
+
+    async def send(request, **_):
+        assert request.data["client_id"] == client_id
+        assert request.data["client_secret"] == secret
+        assert request.data["grant_type"] == "client_credentials"
+        assert request.data["scope"] == scope
+
+        return mock_response(json_payload={"access_token": access_token, "expires_in": 42})
+
+    transport = Mock(send=Mock(wraps=send))
+
+    client = AadClient(tenant_id, client_id, transport=transport)
+    token = await client.obtain_token_by_client_secret(scopes=(scope,), secret=secret)
+
+    assert token.token == access_token
+    assert transport.send.call_count == 1
+
+
 async def test_refresh_token():
     tenant_id = "tenant-id"
     client_id = "client-id"