mac.Write(iv)
		sealingKey := mac.Sum(nil)

		var block cipher.Block
		block, err = aes.NewCipher(sealingKey)
		if err != nil {
			return DEK{}, err
		}
		aead, err = cipher.NewGCM(block)
		if err != nil {
			return DEK{}, err
		}
	case algorithmChaCha20Poly1305:
		var sealingKey []byte
		sealingKey, err = chacha20.HChaCha20(kms.key, iv)
		if err != nil {
			return DEK{}, err

pkg container/list, method (*List) MoveAfter(*Element, *Element)
pkg container/list, method (*List) MoveBefore(*Element, *Element)
pkg crypto, type PublicKey interface {}
pkg crypto/cipher, func NewGCM(Block) (AEAD, error)
pkg crypto/cipher, type AEAD interface { NonceSize, Open, Overhead, Seal }
pkg crypto/cipher, type AEAD interface, NonceSize() int