{Core} Workaround empty and multiple scopes provided by old Track 2 SDKs

src/azure-cli-core/azure/cli/core/adal_authentication.py

@@ -68,14 +68,7 @@ def _get_token(self, sdk_resource=None):
     def get_token(self, *scopes, **kwargs):  # pylint:disable=unused-argument
         logger.debug("AdalAuthentication.get_token invoked by Track 2 SDK with scopes=%s", scopes)
 
-        # Deal with an old Track 2 SDK issue where the default credential_scopes is extended with
-        # custom credential_scopes. Instead, credential_scopes should be replaced by custom credential_scopes.
-        # https://github.com/Azure/azure-sdk-for-python/issues/12947
-        # We simply remove the first one if there are multiple scopes provided.
-        if len(scopes) > 1:
-            scopes = scopes[1:]
-
-        _, token, full_token, _ = self._get_token(scopes_to_resource(scopes))
+        _, token, full_token, _ = self._get_token(_try_scopes_to_resource(scopes))
         try:
             return AccessToken(token, int(full_token['expiresIn'] + time.time()))
         except KeyError:  # needed to deal with differing unserialized MSI token payload
@@ -106,7 +99,10 @@ class MSIAuthenticationWrapper(MSIAuthentication):
     # This method is exposed for Azure Core. Add *scopes, **kwargs to fit azure.core requirement
     def get_token(self, *scopes, **kwargs):  # pylint:disable=unused-argument
         logger.debug("MSIAuthenticationWrapper.get_token invoked by Track 2 SDK with scopes=%s", scopes)
-        self.resource = scopes_to_resource(scopes)
+        resource = _try_scopes_to_resource(scopes)
+        if resource:
+            # If available, use resource provided by SDK
+            self.resource = resource
         self.set_token()
         return AccessToken(self.token['access_token'], int(self.token['expires_on']))
 
@@ -135,3 +131,25 @@ def set_token(self):
     def signed_session(self, session=None):
         logger.debug("MSIAuthenticationWrapper.signed_session invoked by Track 1 SDK")
         super().signed_session(session)
+
+
+def _try_scopes_to_resource(scopes):
+    """Wrap scopes_to_resource to workaround some SDK issues."""
+
+    # Track 2 SDKs generated before https://github.com/Azure/autorest.python/pull/239 don't maintain
+    # credential_scopes and call `get_token` with empty scopes.
+    # As a workaround, return None so that the CLI-managed resource is used.
+    if not scopes:
+        logger.debug("No scope is provided by the SDK, use the CLI-managed resource.")
+        return None
+
+    # Track 2 SDKs generated before https://github.com/Azure/autorest.python/pull/745 extend default
+    # credential_scopes with custom credential_scopes. Instead, credential_scopes should be replaced by
+    # custom credential_scopes. https://github.com/Azure/azure-sdk-for-python/issues/12947
+    # As a workaround, remove the first one if there are multiple scopes provided.
+    if len(scopes) > 1:
+        logger.debug("Multiple scopes are provided by the SDK, discarding the first one: %s", scopes[0])
+        return scopes_to_resource(scopes[1:])
+
+    # Exactly only one scope is provided
+    return scopes_to_resource(scopes)

src/azure-cli-core/azure/cli/core/tests/test_adal_authentication.py

@@ -0,0 +1,30 @@
+# --------------------------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for license information.
+# --------------------------------------------------------------------------------------------
+
+# pylint: disable=line-too-long
+import unittest
+from azure.cli.core.adal_authentication import _try_scopes_to_resource
+
+
+class TestUtils(unittest.TestCase):
+
+    def test_try_scopes_to_resource(self):
+        # Test no scopes
+        self.assertIsNone(_try_scopes_to_resource(()))
+        self.assertIsNone(_try_scopes_to_resource([]))
+        self.assertIsNone(_try_scopes_to_resource(None))
+
+        # Test multiple scopes, with the first one discarded
+        resource = _try_scopes_to_resource(("https://management.core.windows.net//.default",
+                                            "https://management.core.chinacloudapi.cn//.default"))
+        self.assertEqual(resource, "https://management.core.chinacloudapi.cn/")
+
+        # Test single scopes (the correct usage)
+        resource = _try_scopes_to_resource(("https://management.core.chinacloudapi.cn//.default",))
+        self.assertEqual(resource, "https://management.core.chinacloudapi.cn/")
+
+
+if __name__ == '__main__':
+    unittest.main()