// objects are slightly larger due to encryption overhead.
// Further, it decrypts all single-part SSE-S3 encrypted objects
// and formats ETags of SSE-C / SSE-KMS encrypted objects to
// be AWS S3 compliant.
//
// DecryptETags uses a KMS bulk decryption API, if available, which
// is more efficient than decrypting ETags sequentually.
func DecryptETags(ctx context.Context, k kms.KMS, objects []ObjectInfo) error {