_default uses impersonated_credentials method

Author: nolanleastin

google/auth/_default.py

@@ -484,42 +484,8 @@ def _get_impersonated_service_account_credentials(filename, info, scopes):
     from google.auth import impersonated_credentials
 
     try:
-        source_credentials_info = info.get("source_credentials")
-        source_credentials_type = source_credentials_info.get("type")
-        if source_credentials_type == _AUTHORIZED_USER_TYPE:
-            source_credentials, _ = _get_authorized_user_credentials(
-                filename, source_credentials_info
-            )
-        elif source_credentials_type == _SERVICE_ACCOUNT_TYPE:
-            source_credentials, _ = _get_service_account_credentials(
-                filename, source_credentials_info
-            )
-        elif source_credentials_type == _EXTERNAL_ACCOUNT_AUTHORIZED_USER_TYPE:
-            source_credentials, _ = _get_external_account_authorized_user_credentials(
-                filename, source_credentials_info
-            )
-        else:
-            raise exceptions.InvalidType(
-                "source credential of type {} is not supported.".format(
-                    source_credentials_type
-                )
-            )
-        impersonation_url = info.get("service_account_impersonation_url")
-        start_index = impersonation_url.rfind("/")
-        end_index = impersonation_url.find(":generateAccessToken")
-        if start_index == -1 or end_index == -1 or start_index > end_index:
-            raise exceptions.InvalidValue(
-                "Cannot extract target principal from {}".format(impersonation_url)
-            )
-        target_principal = impersonation_url[start_index + 1 : end_index]
-        delegates = info.get("delegates")
-        quota_project_id = info.get("quota_project_id")
-        credentials = impersonated_credentials.Credentials(
-            source_credentials,
-            target_principal,
-            scopes,
-            delegates,
-            quota_project_id=quota_project_id,
+        credentials = impersonated_credentials.Credentials.from_impersonated_account_info(
+            info, scopes=scopes
         )
     except ValueError as caught_exc:
         msg = "Failed to load impersonated service account credentials from {}".format(

google/auth/impersonated_credentials.py

@@ -424,7 +424,7 @@ def _source_credentials_from_impersonated_account_info(cls, info):
 
         Raises:
             InvalidType: If the source_credentials are not a support impersonation type
-            ValueError: If the info is not in the expected format.
+            ValueError: If the source_credentials info is not in the expected format.
         """
         _AUTHORIZED_USER_TYPE = "authorized_user"
         _SERVICE_ACCOUNT_TYPE = "service_account"