Support for AWS SSO (IAM Identity Center)

[tomsing1]

Please specify whether your issue is about:

• a possible bug
• a question about package functionality
• a suggested code or documentation change, improvement to the code, or feature request

Our organization has recently switched to IAM Identity Center (formerly known as AWS SSO) for for authentication. Users obtain temporary credentials for a configured profile with the aws sso login command, as shown in this example from the AWS docs.

Configuring a named profile to use IAM Identity Center creates a JSON file in the ~/.aws/sso/cache directory (see here). I believe all AWS SDKs can use this this for authentication now, as an alternative to the traditional key / secret key combination.

Because credentials are not automatically added to the ~/.aws/.credentials file, the use_credentials() function is currently not aware of them, I think. As a workaround, I currently use the aws-export-credentials tool to update the .credentials file.

It would be great to support authentication with temporary credentials in aws.signature!