EVOLUTION-MANAGER

Edit File: impersonated_credentials.py

# Copyright 2018 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. """Google Cloud Impersonated credentials. This module provides authentication for applications where local credentials impersonates a remote service account using `IAM Credentials API`_. This class can be used to impersonate a service account as long as the original Credential object has the "Service Account Token Creator" role on the target service account. .. _IAM Credentials API: https://cloud.google.com/iam/credentials/reference/rest/ """ import base64 import copy from datetime import datetime import json import six from six.moves import http_client from google.auth import _helpers from google.auth import credentials from google.auth import exceptions from google.auth import jwt from google.auth.transport.requests import AuthorizedSession _DEFAULT_TOKEN_LIFETIME_SECS = 3600 # 1 hour in seconds _IAM_SCOPE = ["https://www.googleapis.com/auth/iam"] _IAM_ENDPOINT = ( "https://iamcredentials.googleapis.com/v1/projects/-" + "/serviceAccounts/{}:generateAccessToken" ) _IAM_SIGN_ENDPOINT = ( "https://iamcredentials.googleapis.com/v1/projects/-" + "/serviceAccounts/{}:signBlob" ) _IAM_IDTOKEN_ENDPOINT = ( "https://iamcredentials.googleapis.com/v1/" + "projects/-/serviceAccounts/{}:generateIdToken" ) _REFRESH_ERROR = "Unable to acquire impersonated credentials" _DEFAULT_TOKEN_LIFETIME_SECS = 3600 # 1 hour in seconds _DEFAULT_TOKEN_URI = "https://oauth2.googleapis.com/token" def _make_iam_token_request( request, principal, headers, body, iam_endpoint_override=None ): """Makes a request to the Google Cloud IAM service for an access token. Args: request (Request): The Request object to use. principal (str): The principal to request an access token for. headers (Mapping[str, str]): Map of headers to transmit. body (Mapping[str, str]): JSON Payload body for the iamcredentials API call. iam_endpoint_override (Optiona[str]): The full IAM endpoint override with the target_principal embedded. This is useful when supporting impersonation with regional endpoints. Raises: google.auth.exceptions.TransportError: Raised if there is an underlying HTTP connection error google.auth.exceptions.RefreshError: Raised if the impersonated credentials are not available. Common reasons are `iamcredentials.googleapis.com` is not enabled or the `Service Account Token Creator` is not assigned """ iam_endpoint = iam_endpoint_override or _IAM_ENDPOINT.format(principal) body = json.dumps(body).encode("utf-8") response = request(url=iam_endpoint, method="POST", headers=headers, body=body) # support both string and bytes type response.data response_body = ( response.data.decode("utf-8") if hasattr(response.data, "decode") else response.data ) if response.status != http_client.OK: exceptions.RefreshError(_REFRESH_ERROR, response_body) try: token_response = json.loads(response_body) token = token_response["accessToken"] expiry = datetime.strptime(token_response["expireTime"], "%Y-%m-%dT%H:%M:%SZ") return token, expiry except (KeyError, ValueError) as caught_exc: new_exc = exceptions.RefreshError( "{}: No access token or invalid expiration in response.".format( _REFRESH_ERROR ), response_body, ) six.raise_from(new_exc, caught_exc) class Credentials(credentials.CredentialsWithQuotaProject, credentials.Signing): """This module defines impersonated credentials which are essentially impersonated identities. Impersonated Credentials allows credentials issued to a user or service account to impersonate another. The target service account must grant the originating credential principal the `Service Account Token Creator`_ IAM role: For more information about Token Creator IAM role and IAMCredentials API, see `Creating Short-Lived Service Account Credentials`_. .. _Service Account Token Creator: https://cloud.google.com/iam/docs/service-accounts#the_service_account_token_creator_role .. _Creating Short-Lived Service Account Credentials: https://cloud.google.com/iam/docs/creating-short-lived-service-account-credentials Usage: First grant source_credentials the `Service Account Token Creator` role on the target account to impersonate. In this example, the service account represented by svc_account.json has the token creator role on `impersonated-account@_project_.iam.gserviceaccount.com`. Enable the IAMCredentials API on the source project: `gcloud services enable iamcredentials.googleapis.com`. Initialize a source credential which does not have access to list bucket:: from google.oauth2 import service_account target_scopes = [ 'https://www.googleapis.com/auth/devstorage.read_only'] source_credentials = ( service_account.Credentials.from_service_account_file( '/path/to/svc_account.json', scopes=target_scopes)) Now use the source credentials to acquire credentials to impersonate another service account:: from google.auth import impersonated_credentials target_credentials = impersonated_credentials.Credentials( source_credentials=source_credentials, target_principal='impersonated-account@_project_.iam.gserviceaccount.com', target_scopes = target_scopes, lifetime=500) Resource access is granted:: client = storage.Client(credentials=target_credentials) buckets = client.list_buckets(project='your_project') for bucket in buckets: print(bucket.name) """ def __init__( self, source_credentials, target_principal, target_scopes, delegates=None, lifetime=_DEFAULT_TOKEN_LIFETIME_SECS, quota_project_id=None, iam_endpoint_override=None, ): """ Args: source_credentials (google.auth.Credentials): The source credential used as to acquire the impersonated credentials. target_principal (str): The service account to impersonate. target_scopes (Sequence[str]): Scopes to request during the authorization grant. delegates (Sequence[str]): The chained list of delegates required to grant the final access_token. If set, the sequence of identities must have "Service Account Token Creator" capability granted to the prceeding identity. For example, if set to [serviceAccountB, serviceAccountC], the source_credential must have the Token Creator role on serviceAccountB. serviceAccountB must have the Token Creator on serviceAccountC. Finally, C must have Token Creator on target_principal. If left unset, source_credential must have that role on target_principal. lifetime (int): Number of seconds the delegated credential should be valid for (upto 3600). quota_project_id (Optional[str]): The project ID used for quota and billing. This project may be different from the project used to create the credentials. iam_endpoint_override (Optiona[str]): The full IAM endpoint override with the target_principal embedded. This is useful when supporting impersonation with regional endpoints. """ super(Credentials, self).__init__() self._source_credentials = copy.copy(source_credentials) # Service account source credentials must have the _IAM_SCOPE # added to refresh correctly. User credentials cannot have # their original scopes modified. if isinstance(self._source_credentials, credentials.Scoped): self._source_credentials = self._source_credentials.with_scopes(_IAM_SCOPE) self._target_principal = target_principal self._target_scopes = target_scopes self._delegates = delegates self._lifetime = lifetime self.token = None self.expiry = _helpers.utcnow() self._quota_project_id = quota_project_id self._iam_endpoint_override = iam_endpoint_override @_helpers.copy_docstring(credentials.Credentials) def refresh(self, request): self._update_token(request) def _update_token(self, request): """Updates credentials with a new access_token representing the impersonated account. Args: request (google.auth.transport.requests.Request): Request object to use for refreshing credentials. """ # Refresh our source credentials if it is not valid. if not self._source_credentials.valid: self._source_credentials.refresh(request) body = { "delegates": self._delegates, "scope": self._target_scopes, "lifetime": str(self._lifetime) + "s", } headers = {"Content-Type": "application/json"} # Apply the source credentials authentication info. self._source_credentials.apply(headers) self.token, self.expiry = _make_iam_token_request( request=request, principal=self._target_principal, headers=headers, body=body, iam_endpoint_override=self._iam_endpoint_override, ) def sign_bytes(self, message): iam_sign_endpoint = _IAM_SIGN_ENDPOINT.format(self._target_principal) body = { "payload": base64.b64encode(message).decode("utf-8"), "delegates": self._delegates, } headers = {"Content-Type": "application/json"} authed_session = AuthorizedSession(self._source_credentials) response = authed_session.post( url=iam_sign_endpoint, headers=headers, json=body ) return base64.b64decode(response.json()["signedBlob"]) @property def signer_email(self): return self._target_principal @property def service_account_email(self): return self._target_principal @property def signer(self): return self @_helpers.copy_docstring(credentials.CredentialsWithQuotaProject) def with_quota_project(self, quota_project_id): return self.__class__( self._source_credentials, target_principal=self._target_principal, target_scopes=self._target_scopes, delegates=self._delegates, lifetime=self._lifetime, quota_project_id=quota_project_id, iam_endpoint_override=self._iam_endpoint_override, ) class IDTokenCredentials(credentials.CredentialsWithQuotaProject): """Open ID Connect ID Token-based service account credentials. """ def __init__( self, target_credentials, target_audience=None, include_email=False, quota_project_id=None, ): """ Args: target_credentials (google.auth.Credentials): The target credential used as to acquire the id tokens for. target_audience (string): Audience to issue the token for. include_email (bool): Include email in IdToken quota_project_id (Optional[str]): The project ID used for quota and billing. """ super(IDTokenCredentials, self).__init__() if not isinstance(target_credentials, Credentials): raise exceptions.GoogleAuthError( "Provided Credential must be " "impersonated_credentials" ) self._target_credentials = target_credentials self._target_audience = target_audience self._include_email = include_email self._quota_project_id = quota_project_id def from_credentials(self, target_credentials, target_audience=None): return self.__class__( target_credentials=self._target_credentials, target_audience=target_audience, include_email=self._include_email, quota_project_id=self._quota_project_id, ) def with_target_audience(self, target_audience): return self.__class__( target_credentials=self._target_credentials, target_audience=target_audience, include_email=self._include_email, quota_project_id=self._quota_project_id, ) def with_include_email(self, include_email): return self.__class__( target_credentials=self._target_credentials, target_audience=self._target_audience, include_email=include_email, quota_project_id=self._quota_project_id, ) @_helpers.copy_docstring(credentials.CredentialsWithQuotaProject) def with_quota_project(self, quota_project_id): return self.__class__( target_credentials=self._target_credentials, target_audience=self._target_audience, include_email=self._include_email, quota_project_id=quota_project_id, ) @_helpers.copy_docstring(credentials.Credentials) def refresh(self, request): iam_sign_endpoint = _IAM_IDTOKEN_ENDPOINT.format( self._target_credentials.signer_email ) body = { "audience": self._target_audience, "delegates": self._target_credentials._delegates, "includeEmail": self._include_email, } headers = {"Content-Type": "application/json"} authed_session = AuthorizedSession( self._target_credentials._source_credentials, auth_request=request ) response = authed_session.post( url=iam_sign_endpoint, headers=headers, data=json.dumps(body).encode("utf-8"), ) id_token = response.json()["token"] self.token = id_token self.expiry = datetime.fromtimestamp(jwt.decode(id_token, verify=False)["exp"])