Replace custom blob gRPC API with ByteStream

client/third_party/google/auth/iam.py

Index: client/third_party/google/auth/iam.py
diff --git a/client/third_party/google/auth/iam.py b/client/third_party/google/auth/iam.py
new file mode 100644
index 0000000000000000000000000000000000000000..e091e47f371d6afe7c265c7c23dd67f291f1693b
--- /dev/null
+++ b/client/third_party/google/auth/iam.py
@@ -0,0 +1,102 @@
+# Copyright 2017 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tools for using the Google `Cloud Identity and Access Management (IAM)
+API`_'s auth-related functionality.
+
+.. _Cloud Identity and Access Management (IAM) API:
+    https://cloud.google.com/iam/docs/
+"""
+
+import base64
+import json
+
+from six.moves import http_client
+
+from google.auth import _helpers
+from google.auth import crypt
+from google.auth import exceptions
+
+_IAM_API_ROOT_URI = 'https://iam.googleapis.com/v1'
+_SIGN_BLOB_URI = (
+    _IAM_API_ROOT_URI + '/projects/-/serviceAccounts/{}:signBlob?alt=json')
+
+
+class Signer(crypt.Signer):
+    """Signs messages using the IAM `signBlob API`_.
+
+    This is useful when you need to sign bytes but do not have access to the
+    credential's private key file.
+
+    .. _signBlob API:
+        https://cloud.google.com/iam/reference/rest/v1/projects.serviceAccounts
+        /signBlob
+    """
+
+    def __init__(self, request, credentials, service_account_email):
+        """
+        Args:
+            request (google.auth.transport.Request): The object used to make
+                HTTP requests.
+            credentials (google.auth.credentials.Credentials): The credentials
+                that will be used to authenticate the request to the IAM API.
+                The credentials must have of one the following scopes:
+
+                - https://www.googleapis.com/auth/iam
+                - https://www.googleapis.com/auth/cloud-platform
+            service_account_email (str): The service account email identifying
+                which service account to use to sign bytes. Often, this can
+                be the same as the service account email in the given
+                credentials.
+        """
+        self._request = request
+        self._credentials = credentials
+        self._service_account_email = service_account_email
+
+    def _make_signing_request(self, message):
+        """Makes a request to the API signBlob API."""
+        message = _helpers.to_bytes(message)
+
+        method = 'POST'
+        url = _SIGN_BLOB_URI.format(self._service_account_email)
+        headers = {}
+        body = json.dumps({
+            'bytesToSign': base64.b64encode(message).decode('utf-8'),
+        })
+
+        self._credentials.before_request(self._request, method, url, headers)
+        response = self._request(
+            url=url, method=method, body=body, headers=headers)
+
+        if response.status != http_client.OK:
+            raise exceptions.TransportError(
+                'Error calling the IAM signBytes API: {}'.format(
+                    response.data))
+
+        return json.loads(response.data.decode('utf-8'))
+
+    @property
+    def key_id(self):
+        """Optional[str]: The key ID used to identify this private key.
+
+        .. warning::
+           This is always ``None``. The key ID used by IAM can not
+           be reliably determined ahead of time.
+        """
+        return None
+
+    @_helpers.copy_docstring(crypt.Signer)
+    def sign(self, message):
+        response = self._make_signing_request(message)
+        return base64.b64decode(response['signature'])