Function scratchstack_aws_signature::get_signing_key_fn

pub fn get_signing_key_fn<F>(f: F) -> GetSigningKeyFn<F>

Wrap an async function taking a signing request and returns a result into a GetSigningKey trait implementation.

The function signature should look like: async fn ..(kind: SigningKeyKind, access_key: String, session_token: Option<String>, request_date: Date<Utc>, region: String, service: String) -> Result<(PrincipalActor, SigningKey), SignatureError>