if err != nil {
		return nil, err
	}
	stream, err := algorithm.Stream(key.Plaintext)
	if err != nil {
		return nil, err
	}
	nonce := make([]byte, stream.NonceSize())
	if _, err := rand.Read(nonce); err != nil {
		return nil, err
	}

	const (
		MaxMetadataSize = 1 << 20 // max. size of the metadata
		Version         = 1
	)
	var (
		header [5]byte

	}

	stream, err := sio.AES_256_GCM.Stream(key)
	if err != nil {
		return err
	}
	// Zero nonce, we only use each key once, and 32 bytes is plenty.
	nonce := make([]byte, stream.NonceSize())
	encr := stream.DecryptReader(r, nonce, nil)
	_, err = io.Copy(w, encr)
	if err == nil {
		fmt.Println(okMsg)
	}
	return err

// JSON-encoded. Now, ciphertexts are binary-encoded.
// Therefore, there is no MarshalJSON implementation.
func (c *ciphertext) UnmarshalJSON(text []byte) error {
	const (
		IVSize    = 16
		NonceSize = 12

		AES256GCM        = "AES-256-GCM-HMAC-SHA-256"
		CHACHA20POLY1305 = "ChaCha20Poly1305"
	)

	type JSON struct {
		Algorithm string `json:"aead"`
		ID        string `json:"id"`