def generate_ecc_signing_key(algorithm):
    """Returns an ECC signing key.

    :param algorithm: Algorithm object which determines what signature to generate
    :type algorithm: aws_encryption_sdk.identifiers.Algorithm
    :returns: Generated signing key
    :raises NotSupportedError: if signing algorithm is not supported on this platform
    """
    try:
        verify_interface(ec.EllipticCurve, algorithm.signing_algorithm_info)
        return ec.generate_private_key(curve=algorithm.signing_algorithm_info(), backend=default_backend())
    except InterfaceNotImplemented:
        raise NotSupportedError("Unsupported signing algorithm info")
Returns an ECC signing key.

    :param algorithm: Algorithm object which determines what signature to generate
    :type algorithm: aws_encryption_sdk.identifiers.Algorithm
    :returns: Generated signing key
    :raises NotSupportedError: if signing algorithm is not supported on this platform