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Diffstat (limited to 'google/oauth2/_reauth_async.py')
| -rw-r--r-- | google/oauth2/_reauth_async.py | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/google/oauth2/_reauth_async.py b/google/oauth2/_reauth_async.py new file mode 100644 index 0000000..0276ddd --- /dev/null +++ b/google/oauth2/_reauth_async.py @@ -0,0 +1,329 @@ +# Copyright 2021 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. + +"""A module that provides functions for handling rapt authentication. + +Reauth is a process of obtaining additional authentication (such as password, +security token, etc.) while refreshing OAuth 2.0 credentials for a user. + +Credentials that use the Reauth flow must have the reauth scope, +``https://www.googleapis.com/auth/accounts.reauth``. + +This module provides a high-level function for executing the Reauth process, +:func:`refresh_grant`, and lower-level helpers for doing the individual +steps of the reauth process. + +Those steps are: + +1. Obtaining a list of challenges from the reauth server. +2. Running through each challenge and sending the result back to the reauth + server. +3. Refreshing the access token using the returned rapt token. +""" + +import sys + +from six.moves import range + +from google.auth import exceptions +from google.oauth2 import _client +from google.oauth2 import _client_async +from google.oauth2 import challenges +from google.oauth2 import reauth + + +async def _get_challenges( + request, supported_challenge_types, access_token, requested_scopes=None +): + """Does initial request to reauth API to get the challenges. + + Args: + request (google.auth.transport.Request): A callable used to make + HTTP requests. This must be an aiohttp request. + supported_challenge_types (Sequence[str]): list of challenge names + supported by the manager. + access_token (str): Access token with reauth scopes. + requested_scopes (Optional(Sequence[str])): Authorized scopes for the credentials. + + Returns: + dict: The response from the reauth API. + """ + body = {"supportedChallengeTypes": supported_challenge_types} + if requested_scopes: + body["oauthScopesForDomainPolicyLookup"] = requested_scopes + + return await _client_async._token_endpoint_request( + request, + reauth._REAUTH_API + ":start", + body, + access_token=access_token, + use_json=True, + ) + + +async def _send_challenge_result( + request, session_id, challenge_id, client_input, access_token +): + """Attempt to refresh access token by sending next challenge result. + + Args: + request (google.auth.transport.Request): A callable used to make + HTTP requests. This must be an aiohttp request. + session_id (str): session id returned by the initial reauth call. + challenge_id (str): challenge id returned by the initial reauth call. + client_input: dict with a challenge-specific client input. For example: + ``{'credential': password}`` for password challenge. + access_token (str): Access token with reauth scopes. + + Returns: + dict: The response from the reauth API. + """ + body = { + "sessionId": session_id, + "challengeId": challenge_id, + "action": "RESPOND", + "proposalResponse": client_input, + } + + return await _client_async._token_endpoint_request( + request, + reauth._REAUTH_API + "/{}:continue".format(session_id), + body, + access_token=access_token, + use_json=True, + ) + + +async def _run_next_challenge(msg, request, access_token): + """Get the next challenge from msg and run it. + + Args: + msg (dict): Reauth API response body (either from the initial request to + https://reauth.googleapis.com/v2/sessions:start or from sending the + previous challenge response to + https://reauth.googleapis.com/v2/sessions/id:continue) + request (google.auth.transport.Request): A callable used to make + HTTP requests. This must be an aiohttp request. + access_token (str): reauth access token + + Returns: + dict: The response from the reauth API. + + Raises: + google.auth.exceptions.ReauthError: if reauth failed. + """ + for challenge in msg["challenges"]: + if challenge["status"] != "READY": + # Skip non-activated challenges. + continue + c = challenges.AVAILABLE_CHALLENGES.get(challenge["challengeType"], None) + if not c: + raise exceptions.ReauthFailError( + "Unsupported challenge type {0}. Supported types: {1}".format( + challenge["challengeType"], + ",".join(list(challenges.AVAILABLE_CHALLENGES.keys())), + ) + ) + if not c.is_locally_eligible: + raise exceptions.ReauthFailError( + "Challenge {0} is not locally eligible".format( + challenge["challengeType"] + ) + ) + client_input = c.obtain_challenge_input(challenge) + if not client_input: + return None + return await _send_challenge_result( + request, + msg["sessionId"], + challenge["challengeId"], + client_input, + access_token, + ) + return None + + +async def _obtain_rapt(request, access_token, requested_scopes): + """Given an http request method and reauth access token, get rapt token. + + Args: + request (google.auth.transport.Request): A callable used to make + HTTP requests. This must be an aiohttp request. + access_token (str): reauth access token + requested_scopes (Sequence[str]): scopes required by the client application + + Returns: + str: The rapt token. + + Raises: + google.auth.exceptions.ReauthError: if reauth failed + """ + msg = await _get_challenges( + request, + list(challenges.AVAILABLE_CHALLENGES.keys()), + access_token, + requested_scopes, + ) + + if msg["status"] == reauth._AUTHENTICATED: + return msg["encodedProofOfReauthToken"] + + for _ in range(0, reauth.RUN_CHALLENGE_RETRY_LIMIT): + if not ( + msg["status"] == reauth._CHALLENGE_REQUIRED + or msg["status"] == reauth._CHALLENGE_PENDING + ): + raise exceptions.ReauthFailError( + "Reauthentication challenge failed due to API error: {}".format( + msg["status"] + ) + ) + + if not reauth.is_interactive(): + raise exceptions.ReauthFailError( + "Reauthentication challenge could not be answered because you are not" + " in an interactive session." + ) + + msg = await _run_next_challenge(msg, request, access_token) + + if msg["status"] == reauth._AUTHENTICATED: + return msg["encodedProofOfReauthToken"] + + # If we got here it means we didn't get authenticated. + raise exceptions.ReauthFailError("Failed to obtain rapt token.") + + +async def get_rapt_token( + request, client_id, client_secret, refresh_token, token_uri, scopes=None +): + """Given an http request method and refresh_token, get rapt token. + + Args: + request (google.auth.transport.Request): A callable used to make + HTTP requests. This must be an aiohttp request. + client_id (str): client id to get access token for reauth scope. + client_secret (str): client secret for the client_id + refresh_token (str): refresh token to refresh access token + token_uri (str): uri to refresh access token + scopes (Optional(Sequence[str])): scopes required by the client application + + Returns: + str: The rapt token. + Raises: + google.auth.exceptions.RefreshError: If reauth failed. + """ + sys.stderr.write("Reauthentication required.\n") + + # Get access token for reauth. + access_token, _, _, _ = await _client_async.refresh_grant( + request=request, + client_id=client_id, + client_secret=client_secret, + refresh_token=refresh_token, + token_uri=token_uri, + scopes=[reauth._REAUTH_SCOPE], + ) + + # Get rapt token from reauth API. + rapt_token = await _obtain_rapt(request, access_token, requested_scopes=scopes) + + return rapt_token + + +async def refresh_grant( + request, + token_uri, + refresh_token, + client_id, + client_secret, + scopes=None, + rapt_token=None, + enable_reauth_refresh=False, +): + """Implements the reauthentication flow. + + Args: + request (google.auth.transport.Request): A callable used to make + HTTP requests. This must be an aiohttp request. + token_uri (str): The OAuth 2.0 authorizations server's token endpoint + URI. + refresh_token (str): The refresh token to use to get a new access + token. + client_id (str): The OAuth 2.0 application's client ID. + client_secret (str): The Oauth 2.0 appliaction's client secret. + scopes (Optional(Sequence[str])): Scopes to request. If present, all + scopes must be authorized for the refresh token. Useful if refresh + token has a wild card scope (e.g. + 'https://www.googleapis.com/auth/any-api'). + rapt_token (Optional(str)): The rapt token for reauth. + enable_reauth_refresh (Optional[bool]): Whether reauth refresh flow + should be used. The default value is False. This option is for + gcloud only, other users should use the default value. + + Returns: + Tuple[str, Optional[str], Optional[datetime], Mapping[str, str], str]: The + access token, new refresh token, expiration, the additional data + returned by the token endpoint, and the rapt token. + + Raises: + google.auth.exceptions.RefreshError: If the token endpoint returned + an error. + """ + body = { + "grant_type": _client._REFRESH_GRANT_TYPE, + "client_id": client_id, + "client_secret": client_secret, + "refresh_token": refresh_token, + } + if scopes: + body["scope"] = " ".join(scopes) + if rapt_token: + body["rapt"] = rapt_token + + response_status_ok, response_data = await _client_async._token_endpoint_request_no_throw( + request, token_uri, body + ) + if ( + not response_status_ok + and response_data.get("error") == reauth._REAUTH_NEEDED_ERROR + and ( + response_data.get("error_subtype") + == reauth._REAUTH_NEEDED_ERROR_INVALID_RAPT + or response_data.get("error_subtype") + == reauth._REAUTH_NEEDED_ERROR_RAPT_REQUIRED + ) + ): + if not enable_reauth_refresh: + raise exceptions.RefreshError( + "Reauthentication is needed. Please run `gcloud auth login --update-adc` to reauthenticate." + ) + + rapt_token = await get_rapt_token( + request, client_id, client_secret, refresh_token, token_uri, scopes=scopes + ) + body["rapt"] = rapt_token + ( + response_status_ok, + response_data, + ) = await _client_async._token_endpoint_request_no_throw( + request, token_uri, body + ) + + if not response_status_ok: + _client._handle_error_response(response_data) + refresh_response = _client._handle_refresh_grant_response( + response_data, refresh_token + ) + return refresh_response + (rapt_token,) |