def get_http_authentication(private_key: RsaKey, private_key_id: str) -> HTTPSignatureHeaderAuth:
    """
    Get HTTP signature authentication for a request.
    """
    key = private_key.exportKey()
    return HTTPSignatureHeaderAuth(
        headers=["(request-target)", "user-agent", "host", "date"],
        algorithm="rsa-sha256",
        key=key,
        key_id=private_key_id,
    )
Get HTTP signature authentication for a request.