var aead cipher.AEAD
	switch algorithm {
	case algorithmAESGCM:
		mac := hmac.New(sha256.New, kms.key)
		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

pkg crypto, method (Hash) New() hash.Hash
pkg crypto, method (Hash) Size() int
pkg crypto, type Hash uint
pkg crypto, type PrivateKey interface {}
pkg crypto/aes, const BlockSize ideal-int
pkg crypto/aes, func NewCipher([]uint8) (cipher.Block, error)
pkg crypto/aes, method (KeySizeError) Error() string
pkg crypto/aes, type KeySizeError int
pkg crypto/cipher, func NewCBCDecrypter(Block, []uint8) BlockMode