chore: 添加虚拟环境到仓库

- 添加 backend_service/venv 虚拟环境
- 包含所有Python依赖包
- 注意：虚拟环境约393MB，包含12655个文件

backend_service/venv/lib/python3.13/site-packages/google/oauth2/sts.py

@@ -0,0 +1,176 @@
+# Copyright 2020 Google LLC
+#
+# 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.
+
+"""OAuth 2.0 Token Exchange Spec.
+
+This module defines a token exchange utility based on the `OAuth 2.0 Token
+Exchange`_ spec. This will be mainly used to exchange external credentials
+for GCP access tokens in workload identity pools to access Google APIs.
+
+The implementation will support various types of client authentication as
+allowed in the spec.
+
+A deviation on the spec will be for additional Google specific options that
+cannot be easily mapped to parameters defined in the RFC.
+
+The returned dictionary response will be based on the `rfc8693 section 2.2.1`_
+spec JSON response.
+
+.. _OAuth 2.0 Token Exchange: https://tools.ietf.org/html/rfc8693
+.. _rfc8693 section 2.2.1: https://tools.ietf.org/html/rfc8693#section-2.2.1
+"""
+
+import http.client as http_client
+import json
+import urllib
+
+from google.oauth2 import utils
+
+
+_URLENCODED_HEADERS = {"Content-Type": "application/x-www-form-urlencoded"}
+
+
+class Client(utils.OAuthClientAuthHandler):
+    """Implements the OAuth 2.0 token exchange spec based on
+    https://tools.ietf.org/html/rfc8693.
+    """
+
+    def __init__(self, token_exchange_endpoint, client_authentication=None):
+        """Initializes an STS client instance.
+
+        Args:
+            token_exchange_endpoint (str): The token exchange endpoint.
+            client_authentication (Optional(google.oauth2.oauth2_utils.ClientAuthentication)):
+                The optional OAuth client authentication credentials if available.
+        """
+        super(Client, self).__init__(client_authentication)
+        self._token_exchange_endpoint = token_exchange_endpoint
+
+    def _make_request(self, request, headers, request_body):
+        # Initialize request headers.
+        request_headers = _URLENCODED_HEADERS.copy()
+
+        # Inject additional headers.
+        if headers:
+            for k, v in dict(headers).items():
+                request_headers[k] = v
+
+        # Apply OAuth client authentication.
+        self.apply_client_authentication_options(request_headers, request_body)
+
+        # Execute request.
+        response = request(
+            url=self._token_exchange_endpoint,
+            method="POST",
+            headers=request_headers,
+            body=urllib.parse.urlencode(request_body).encode("utf-8"),
+        )
+
+        response_body = (
+            response.data.decode("utf-8")
+            if hasattr(response.data, "decode")
+            else response.data
+        )
+
+        # If non-200 response received, translate to OAuthError exception.
+        if response.status != http_client.OK:
+            utils.handle_error_response(response_body)
+
+        response_data = json.loads(response_body)
+
+        # Return successful response.
+        return response_data
+
+    def exchange_token(
+        self,
+        request,
+        grant_type,
+        subject_token,
+        subject_token_type,
+        resource=None,
+        audience=None,
+        scopes=None,
+        requested_token_type=None,
+        actor_token=None,
+        actor_token_type=None,
+        additional_options=None,
+        additional_headers=None,
+    ):
+        """Exchanges the provided token for another type of token based on the
+        rfc8693 spec.
+
+        Args:
+            request (google.auth.transport.Request): A callable used to make
+                HTTP requests.
+            grant_type (str): The OAuth 2.0 token exchange grant type.
+            subject_token (str): The OAuth 2.0 token exchange subject token.
+            subject_token_type (str): The OAuth 2.0 token exchange subject token type.
+            resource (Optional[str]): The optional OAuth 2.0 token exchange resource field.
+            audience (Optional[str]): The optional OAuth 2.0 token exchange audience field.
+            scopes (Optional[Sequence[str]]): The optional list of scopes to use.
+            requested_token_type (Optional[str]): The optional OAuth 2.0 token exchange requested
+                token type.
+            actor_token (Optional[str]): The optional OAuth 2.0 token exchange actor token.
+            actor_token_type (Optional[str]): The optional OAuth 2.0 token exchange actor token type.
+            additional_options (Optional[Mapping[str, str]]): The optional additional
+                non-standard Google specific options.
+            additional_headers (Optional[Mapping[str, str]]): The optional additional
+                headers to pass to the token exchange endpoint.
+
+        Returns:
+            Mapping[str, str]: The token exchange JSON-decoded response data containing
+                the requested token and its expiration time.
+
+        Raises:
+            google.auth.exceptions.OAuthError: If the token endpoint returned
+                an error.
+        """
+        # Initialize request body.
+        request_body = {
+            "grant_type": grant_type,
+            "resource": resource,
+            "audience": audience,
+            "scope": " ".join(scopes or []),
+            "requested_token_type": requested_token_type,
+            "subject_token": subject_token,
+            "subject_token_type": subject_token_type,
+            "actor_token": actor_token,
+            "actor_token_type": actor_token_type,
+            "options": None,
+        }
+        # Add additional non-standard options.
+        if additional_options:
+            request_body["options"] = urllib.parse.quote(json.dumps(additional_options))
+        # Remove empty fields in request body.
+        for k, v in dict(request_body).items():
+            if v is None or v == "":
+                del request_body[k]
+
+        return self._make_request(request, additional_headers, request_body)
+
+    def refresh_token(self, request, refresh_token):
+        """Exchanges a refresh token for an access token based on the
+        RFC6749 spec.
+
+        Args:
+            request (google.auth.transport.Request): A callable used to make
+                HTTP requests.
+            subject_token (str): The OAuth 2.0 refresh token.
+        """
+
+        return self._make_request(
+            request,
+            None,
+            {"grant_type": "refresh_token", "refresh_token": refresh_token},
+        )