}
	header[0] = Version
	binary.LittleEndian.PutUint32(header[1:], uint32(len(metadata)))
	buffer.Write(header[:])
	buffer.Write(metadata)

	return io.MultiReader(
		&buffer,
		stream.EncryptReader(plaintext, nonce, nil),
	), nil
}

// Decrypt decrypts the ciphertext using a key managed by the KMS.
// The same context that have been used during encryption must be
// provided.

	return
}

// EncryptSinglePart encrypts an io.Reader which must be the
// body of a single-part PUT request.
func EncryptSinglePart(r io.Reader, key ObjectKey) io.Reader {
	r, err := sio.EncryptReader(r, sio.Config{MinVersion: sio.Version20, Key: key[:], CipherSuites: fips.DARECiphers()})
	if err != nil {
		logger.CriticalIf(context.Background(), errors.New("Unable to encrypt io.Reader using object key"))
	}
	return r

		var nonce [12]byte
		tmp := sha256.Sum256([]byte(fmt.Sprint(uploadID, partID)))
		copy(nonce[:], tmp[:12])

		partEncryptionKey := objectEncryptionKey.DerivePartKey(uint32(partID))
		encReader, err := sio.EncryptReader(reader, sio.Config{
			Key:          partEncryptionKey[:],
			CipherSuites: fips.DARECiphers(),
			Nonce:        &nonce,
		})
		if err != nil {
			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)

	objectEncryptionKey, err := newEncryptMetadata(ctx, kind, keyID, key, bucket, object, metadata, cryptoCtx)
	if err != nil {
		return nil, crypto.ObjectKey{}, err
	}

	reader, err := sio.EncryptReader(content, sio.Config{Key: objectEncryptionKey[:], MinVersion: sio.Version20, CipherSuites: fips.DARECiphers()})
	if err != nil {
		return nil, crypto.ObjectKey{}, crypto.ErrInvalidCustomerKey
	}

}

// SealMD5CurrFn seals md5sum with object encryption key and returns sealed
// md5sum
type SealMD5CurrFn func([]byte) []byte

// PutObjReader is a type that wraps sio.EncryptReader and
// underlying hash.Reader in a struct
type PutObjReader struct {
	*hash.Reader              // actual data stream
	rawReader    *hash.Reader // original data stream
	sealMD5Fn    SealMD5CurrFn
}