diff options
Diffstat (limited to 'google/oauth2/id_token.py')
| -rw-r--r-- | google/oauth2/id_token.py | 89 |
1 files changed, 45 insertions, 44 deletions
diff --git a/google/oauth2/id_token.py b/google/oauth2/id_token.py index 5fbb6a1..540ccd1 100644 --- a/google/oauth2/id_token.py +++ b/google/oauth2/id_token.py @@ -179,13 +179,14 @@ def verify_firebase_token(id_token, request, audience=None): def fetch_id_token(request, audience): """Fetch the ID Token from the current environment. - This function acquires ID token from the environment in the following order: + This function acquires ID token from the environment in the following order. + See https://google.aip.dev/auth/4110. - 1. If the application is running in Compute Engine, App Engine or Cloud Run, - then the ID token are obtained from the metadata server. - 2. If the environment variable ``GOOGLE_APPLICATION_CREDENTIALS`` is set + 1. If the environment variable ``GOOGLE_APPLICATION_CREDENTIALS`` is set to the path of a valid service account JSON file, then ID token is acquired using this service account credentials. + 2. If the application is running in Compute Engine, App Engine or Cloud Run, + then the ID token are obtained from the metadata server. 3. If metadata server doesn't exist and no valid service account credentials are found, :class:`~google.auth.exceptions.DefaultCredentialsError` will be raised. @@ -213,51 +214,51 @@ def fetch_id_token(request, audience): If metadata server doesn't exist and no valid service account credentials are found. """ - # 1. First try to fetch ID token from metada server if it exists. The code - # works for GAE and Cloud Run metadata server as well. - try: - from google.auth import compute_engine - - credentials = compute_engine.IDTokenCredentials( - request, audience, use_metadata_identity_endpoint=True - ) - credentials.refresh(request) - return credentials.token - except (ImportError, exceptions.TransportError, exceptions.RefreshError): - pass - - # 2. Try to use service account credentials to get ID token. - - # Try to get credentials from the GOOGLE_APPLICATION_CREDENTIALS environment + # 1. Try to get credentials from the GOOGLE_APPLICATION_CREDENTIALS environment # variable. credentials_filename = os.environ.get(environment_vars.CREDENTIALS) - if not ( - credentials_filename - and os.path.exists(credentials_filename) - and os.path.isfile(credentials_filename) - ): - raise exceptions.DefaultCredentialsError( - "Neither metadata server or valid service account credentials are found." - ) + if credentials_filename: + if not ( + os.path.exists(credentials_filename) + and os.path.isfile(credentials_filename) + ): + raise exceptions.DefaultCredentialsError( + "GOOGLE_APPLICATION_CREDENTIALS path is either not found or invalid." + ) - try: - with open(credentials_filename, "r") as f: - info = json.load(f) - credentials_content = ( - (info.get("type") == "service_account") and info or None + try: + with open(credentials_filename, "r") as f: + from google.oauth2 import service_account + + info = json.load(f) + if info.get("type") == "service_account": + credentials = service_account.IDTokenCredentials.from_service_account_info( + info, target_audience=audience + ) + credentials.refresh(request) + return credentials.token + except ValueError as caught_exc: + new_exc = exceptions.DefaultCredentialsError( + "GOOGLE_APPLICATION_CREDENTIALS is not valid service account credentials.", + caught_exc, ) + six.raise_from(new_exc, caught_exc) - from google.oauth2 import service_account + # 2. Try to fetch ID token from metada server if it exists. The code works for GAE and + # Cloud Run metadata server as well. + try: + from google.auth import compute_engine + from google.auth.compute_engine import _metadata - credentials = service_account.IDTokenCredentials.from_service_account_info( - credentials_content, target_audience=audience + if _metadata.ping(request): + credentials = compute_engine.IDTokenCredentials( + request, audience, use_metadata_identity_endpoint=True ) - except ValueError as caught_exc: - new_exc = exceptions.DefaultCredentialsError( - "Neither metadata server or valid service account credentials are found.", - caught_exc, - ) - six.raise_from(new_exc, caught_exc) + credentials.refresh(request) + return credentials.token + except (ImportError, exceptions.TransportError): + pass - credentials.refresh(request) - return credentials.token + raise exceptions.DefaultCredentialsError( + "Neither metadata server or valid service account credentials are found." + ) |