}

	prefix := fmt.Sprintf("%s %s:", signV2Algorithm, cred.AccessKey)
	if !strings.HasPrefix(v2Auth, prefix) {
		return ErrSignatureDoesNotMatch
	}
	v2Auth = v2Auth[len(prefix):]
	expectedAuth := signatureV2(cred, r.Method, encodedResource, strings.Join(unescapedQueries, "&"), r.Header)
	if !compareSignatureV2(v2Auth, expectedAuth) {
		return ErrSignatureDoesNotMatch
	}
	return ErrNone
}