if err != nil {
			return nil, err
		}
		aead, err = cipher.NewGCM(block)
		if err != nil {
			return nil, err
		}
	case kms.ChaCha20:
		sealingKey, err := chacha20.HChaCha20(s.key, iv)
		if err != nil {
			return nil, err
		}
		aead, err = chacha20poly1305.New(sealingKey)
		if err != nil {
			return nil, err
		}
	default:
		return nil, ErrDecrypt
	}