# Copyright 2016 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.
"""OAuth 2.0 Credentials.
This module provides credentials based on OAuth 2.0 access and refresh tokens.
These credentials usually access resources on behalf of a user (resource
owner).
Specifically, this is intended to use access tokens acquired using the
`Authorization Code grant`_ and can refresh those tokens using a
optional `refresh token`_.
Obtaining the initial access and refresh token is outside of the scope of this
module. Consult `rfc6749 section 4.1`_ for complete details on the
Authorization Code grant flow.
.. _Authorization Code grant: https://tools.ietf.org/html/rfc6749#section-1.3.1
.. _refresh token: https://tools.ietf.org/html/rfc6749#section-6
.. _rfc6749 section 4.1: https://tools.ietf.org/html/rfc6749#section-4.1
"""
import io
import json
import six
from google.auth import _helpers
from google.auth import credentials
from google.auth import exceptions
from google.oauth2 import _client
# The Google OAuth 2.0 token endpoint. Used for authorized user credentials.
_GOOGLE_OAUTH2_TOKEN_ENDPOINT = "https://oauth2.googleapis.com/token"
[docs]class Credentials(credentials.ReadOnlyScoped, credentials.Credentials):
"""Credentials using OAuth 2.0 access and refresh tokens."""
def __init__(
self,
token,
refresh_token=None,
id_token=None,
token_uri=None,
client_id=None,
client_secret=None,
scopes=None,
):
"""
Args:
token (Optional(str)): The OAuth 2.0 access token. Can be None
if refresh information is provided.
refresh_token (str): The OAuth 2.0 refresh token. If specified,
credentials can be refreshed.
id_token (str): The Open ID Connect ID Token.
token_uri (str): The OAuth 2.0 authorization server's token
endpoint URI. Must be specified for refresh, can be left as
None if the token can not be refreshed.
client_id (str): The OAuth 2.0 client ID. Must be specified for
refresh, can be left as None if the token can not be refreshed.
client_secret(str): The OAuth 2.0 client secret. Must be specified
for refresh, can be left as None if the token can not be
refreshed.
scopes (Sequence[str]): The scopes used to obtain authorization.
This parameter is used by :meth:`has_scopes`. OAuth 2.0
credentials can not request additional scopes after
authorization. The scopes must be derivable from the refresh
token if refresh information is provided (e.g. The refresh
token scopes are a superset of this or contain a wild card
scope like 'https://www.googleapis.com/auth/any-api').
"""
super(Credentials, self).__init__()
self.token = token
self._refresh_token = refresh_token
self._id_token = id_token
self._scopes = scopes
self._token_uri = token_uri
self._client_id = client_id
self._client_secret = client_secret
@property
def refresh_token(self):
"""Optional[str]: The OAuth 2.0 refresh token."""
return self._refresh_token
@property
def token_uri(self):
"""Optional[str]: The OAuth 2.0 authorization server's token endpoint
URI."""
return self._token_uri
@property
def id_token(self):
"""Optional[str]: The Open ID Connect ID Token.
Depending on the authorization server and the scopes requested, this
may be populated when credentials are obtained and updated when
:meth:`refresh` is called. This token is a JWT. It can be verified
and decoded using :func:`google.oauth2.id_token.verify_oauth2_token`.
"""
return self._id_token
@property
def client_id(self):
"""Optional[str]: The OAuth 2.0 client ID."""
return self._client_id
@property
def client_secret(self):
"""Optional[str]: The OAuth 2.0 client secret."""
return self._client_secret
@property
def requires_scopes(self):
"""False: OAuth 2.0 credentials have their scopes set when
the initial token is requested and can not be changed."""
return False
[docs] @_helpers.copy_docstring(credentials.Credentials)
def refresh(self, request):
if (
self._refresh_token is None
or self._token_uri is None
or self._client_id is None
or self._client_secret is None
):
raise exceptions.RefreshError(
"The credentials do not contain the necessary fields need to "
"refresh the access token. You must specify refresh_token, "
"token_uri, client_id, and client_secret."
)
access_token, refresh_token, expiry, grant_response = _client.refresh_grant(
request,
self._token_uri,
self._refresh_token,
self._client_id,
self._client_secret,
self._scopes,
)
self.token = access_token
self.expiry = expiry
self._refresh_token = refresh_token
self._id_token = grant_response.get("id_token")
if self._scopes and "scopes" in grant_response:
requested_scopes = frozenset(self._scopes)
granted_scopes = frozenset(grant_response["scopes"].split())
scopes_requested_but_not_granted = requested_scopes - granted_scopes
if scopes_requested_but_not_granted:
raise exceptions.RefreshError(
"Not all requested scopes were granted by the "
"authorization server, missing scopes {}.".format(
", ".join(scopes_requested_but_not_granted)
)
)
[docs] @classmethod
def from_authorized_user_info(cls, info, scopes=None):
"""Creates a Credentials instance from parsed authorized user info.
Args:
info (Mapping[str, str]): The authorized user info in Google
format.
scopes (Sequence[str]): Optional list of scopes to include in the
credentials.
Returns:
google.oauth2.credentials.Credentials: The constructed
credentials.
Raises:
ValueError: If the info is not in the expected format.
"""
keys_needed = set(("refresh_token", "client_id", "client_secret"))
missing = keys_needed.difference(six.iterkeys(info))
if missing:
raise ValueError(
"Authorized user info was not in the expected format, missing "
"fields {}.".format(", ".join(missing))
)
return cls(
None, # No access token, must be refreshed.
refresh_token=info["refresh_token"],
token_uri=_GOOGLE_OAUTH2_TOKEN_ENDPOINT,
scopes=scopes,
client_id=info["client_id"],
client_secret=info["client_secret"],
)
[docs] @classmethod
def from_authorized_user_file(cls, filename, scopes=None):
"""Creates a Credentials instance from an authorized user json file.
Args:
filename (str): The path to the authorized user json file.
scopes (Sequence[str]): Optional list of scopes to include in the
credentials.
Returns:
google.oauth2.credentials.Credentials: The constructed
credentials.
Raises:
ValueError: If the file is not in the expected format.
"""
with io.open(filename, "r", encoding="utf-8") as json_file:
data = json.load(json_file)
return cls.from_authorized_user_info(data, scopes)
