google.auth.aws module

AWS Credentials and AWS Signature V4 Request Signer.

This module provides credentials to access Google Cloud resources from Amazon Web Services (AWS) workloads. These credentials are recommended over the use of service account credentials in AWS as they do not involve the management of long-live service account private keys.

AWS Credentials are initialized using external_account arguments which are typically loaded from the external credentials JSON file. Unlike other Credentials that can be initialized with a list of explicit arguments, secrets or credentials, external account clients use the environment and hints/guidelines provided by the external_account JSON file to retrieve credentials and exchange them for Google access tokens.

This module also provides a basic implementation of the AWS Signature Version 4 request signing algorithm.

AWS Credentials use serialized signed requests to the AWS STS GetCallerIdentity API that can be exchanged for Google access tokens via the GCP STS endpoint.

class RequestSigner(region_name)

Bases: object

Implements an AWS request signer based on the AWS Signature Version 4 signing process. https://docs.aws.amazon.com/general/latest/gr/signature-version-4.html

Instantiates an AWS request signer used to compute authenticated signed requests to AWS APIs based on the AWS Signature Version 4 signing process.

Parameters:region_name (str) – The AWS region to use.

get_request_options(aws_security_credentials, url, method, request_payload='', additional_headers={})

Generates the signed request for the provided HTTP request for calling an AWS API. This follows the steps described at: https://docs.aws.amazon.com/general/latest/gr/sigv4_signing.html

Parameters:

• aws_security_credentials (Mapping [ str, str ]) – A dictionary containing the AWS security credentials.
• url (str) – The AWS service URL containing the canonical URI and query string.
• method (str) – The HTTP method used to call this API.
• request_payload (Optional [ str ]) – The optional request payload if available.
• additional_headers (Optional [ Mapping [ str, str ] ]) – The optional additional headers needed for the requested AWS API.

Returns:

The AWS signed request dictionary object.

Return type:

Mapping [ str, str ]

class Credentials(audience, subject_token_type, token_url, credential_source=None, service_account_impersonation_url=None, client_id=None, client_secret=None, quota_project_id=None, scopes=None, default_scopes=None)

Bases: google.auth.external_account.Credentials

AWS external account credentials. This is used to exchange serialized AWS signature v4 signed requests to AWS STS GetCallerIdentity service for Google access tokens.

Instantiates an AWS workload external account credentials object.

Parameters:

• audience (str) – The STS audience field.
• subject_token_type (str) – The subject token type.
• token_url (str) – The STS endpoint URL.
• credential_source (Mapping) – The credential source dictionary used to provide instructions on how to retrieve external credential to be exchanged for Google access tokens.
• service_account_impersonation_url (Optional [ str ]) – The optional service account impersonation getAccessToken URL.
• client_id (Optional [ str ]) – The optional client ID.
• client_secret (Optional [ str ]) – The optional client secret.
• quota_project_id (Optional [ str ]) – The optional quota project ID.
• scopes (Optional [ Sequence [ str ] ]) – Optional scopes to request during the authorization grant.
• default_scopes (Optional [ Sequence [ str ] ]) – Default scopes passed by a Google client library. Use ‘scopes’ for user-defined scopes.

Raises:

• google.auth.exceptions.RefreshError – If an error is encountered during access token retrieval logic.
• ValueError – For invalid parameters.

Note

Typically one of the helper constructors from_file() or from_info() are used instead of calling the constructor directly.

retrieve_subject_token(request)

Retrieves the subject token using the credential_source object. The subject token is a serialized AWS GetCallerIdentity signed request.

The logic is summarized as:

Retrieve the AWS region from the AWS_REGION or AWS_DEFAULT_REGION environment variable or from the AWS metadata server availability-zone if not found in the environment variable.

Check AWS credentials in environment variables. If not found, retrieve from the AWS metadata server security-credentials endpoint.

When retrieving AWS credentials from the metadata server security-credentials endpoint, the AWS role needs to be determined by calling the security-credentials endpoint without any argument. Then the credentials can be retrieved via: security-credentials/role_name

Generate the signed request to AWS STS GetCallerIdentity action.

Inject x-goog-cloud-target-resource into header and serialize the signed request. This will be the subject-token to pass to GCP STS.

Parameters:request (google.auth.transport.Request) – A callable used to make HTTP requests. Returns:The retrieved subject token. Return type:str

classmethod from_info(info, **kwargs)

Creates an AWS Credentials instance from parsed external account info.

Parameters:

• info (Mapping [ str, str ]) – The AWS external account info in Google format.
• kwargs – Additional arguments to pass to the constructor.

Returns:

The constructed credentials.

Return type:

google.auth.aws.Credentials

Raises:

ValueError – For invalid parameters.

classmethod from_file(filename, **kwargs)

Creates an AWS Credentials instance from an external account json file.

Parameters:

• filename (str) – The path to the AWS external account json file.
• kwargs – Additional arguments to pass to the constructor.

Returns:

The constructed credentials.

Return type:

google.auth.aws.Credentials

apply(headers, token=None)

Apply the token to the authentication header.

Parameters:

• headers (Mapping) – The HTTP request headers.
• token (Optional [ str ]) – If specified, overrides the current access token.

before_request(request, method, url, headers)

Performs credential-specific before request logic.

Refreshes the credentials if necessary, then calls apply() to apply the token to the authentication header.

Parameters:

• request (google.auth.transport.Request) – The object used to make HTTP requests.
• method (str) – The request’s HTTP method or the RPC method being invoked.
• url (str) – The request’s URI or the RPC service’s URI.
• headers (Mapping) – The request’s headers.

default_scopes

the credentials’ current set of default scopes.

Type:Sequence [ str ]

expired

Checks if the credentials are expired.

Note that credentials can be invalid but not expired because Credentials with expiry set to None is considered to never expire.

get_project_id(request)

Retrieves the project ID corresponding to the workload identity pool.

When not determinable, None is returned.

This is introduced to support the current pattern of using the Auth library:

credentials, project_id = google.auth.default()

The resource may not have permission (resourcemanager.projects.get) to call this API or the required scopes may not be selected: https://cloud.google.com/resource-manager/reference/rest/v1/projects/get#authorization-scopes

Parameters:request (google.auth.transport.Request) – A callable used to make HTTP requests. Returns:

The project ID corresponding to the workload identity pool

if determinable.

Return type:Optional [ str ]

has_scopes(scopes)

Checks if the credentials have the given scopes.

Parameters:scopes (Sequence [ str ]) – The list of scopes to check. Returns:True if the credentials have the given scopes. Return type:bool

project_number

The project number corresponding to the workload identity pool.

Type:Optional [ str ]

quota_project_id

Project to use for quota and billing purposes.

refresh(request)

Refreshes the access token.

Parameters:request (google.auth.transport.Request) – The object used to make HTTP requests. Raises:google.auth.exceptions.RefreshError – If the credentials could not be refreshed.

requires_scopes

Checks if the credentials requires scopes.

Returns:True if there are no scopes set otherwise False. Return type:bool

scopes

the credentials’ current set of scopes.

Type:Sequence [ str ]

valid

Checks the validity of the credentials.

This is True if the credentials have a token and the token is not expired.

with_quota_project(quota_project_id)

Returns a copy of these credentials with a modified quota project.

Parameters:quota_project_id (str) – The project to use for quota and billing purposes Returns:A new credentials instance. Return type:google.oauth2.credentials.Credentials

with_scopes(scopes, default_scopes=None)

Create a copy of these credentials with the specified scopes.

Parameters:scopes (Sequence [ str ]) – The list of scopes to attach to the current credentials. Raises:NotImplementedError – If the credentials’ scopes can not be changed. This can be avoided by checking requires_scopes before calling this method.