signature/policy_reference_match.go
func parseDockerReferences(s1, s2 string) (reference.Named, reference.Named, error) {
	r1, err := reference.ParseNormalizedNamed(s1)
	if err != nil {
		return nil, nil, err
	}
	r2, err := reference.ParseNormalizedNamed(s2)
	if err != nil {
		return nil, nil, err
	}
	return r1, r2, nil
}
func parseDockerReferences(s1, s2 string) (reference.Named, reference.Named, error) {
	r1, err := reference.ParseNormalizedNamed(s1)
	if err != nil {
		return nil, nil, err
	}
	r2, err := reference.ParseNormalizedNamed(s2)
	if err != nil {
		return nil, nil, err
	}
	return r1, r2, nil
}
// parseDockerReferences converts two reference strings into parsed entities, failing on any error