type tripleDESCipher struct {
	cipher1, cipher2, cipher3 desCipher
}

// NewTripleDESCipher creates and returns a new [cipher.Block].
func NewTripleDESCipher(key []byte) (cipher.Block, error) {
	if len(key) != 24 {
		return nil, KeySizeError(len(key))
	}

	c := new(tripleDESCipher)
	c.cipher1.generateSubkeys(key[:8])
	c.cipher2.generateSubkeys(key[8:16])
	c.cipher3.generateSubkeys(key[16:])
	return c, nil
}

func counterCryptASM(nr int, out, in []byte, counter *[gcmBlockSize]byte, key *uint32)

// NewGCM returns the AES cipher wrapped in Galois Counter Mode. This is only
// called by [crypto/cipher.NewGCM] via the gcmAble interface.
func (c *aesCipherAsm) NewGCM(nonceSize, tagSize int) (cipher.AEAD, error) {
	var h1, h2 uint64
	g := &gcmAsm{cipher: c, ks: c.enc[:c.l], nonceSize: nonceSize, tagSize: tagSize}

	hle := make([]byte, gcmBlockSize)

	for _, cipher := range tls.InsecureCipherSuites() {
		acceptedCiphers[cipher.Name] = cipher.ID
	}
	for _, cipher := range tls.CipherSuites() {
		acceptedCiphers[cipher.Name] = cipher.ID
	}
	return acceptedCiphers
}

// TLSCipherSuites returns a list of cipher suite IDs from the cipher suite names passed.
func TLSCipherSuites(cipherNames []string) ([]uint16, error) {

type aesctr struct {
	block   *aesCipherAsm          // block cipher
	ctr     [2]uint64              // next value of the counter (big endian)
	buffer  []byte                 // buffer for the encrypted counter values
	storage [streamBufferSize]byte // array backing buffer slice
}

// NewCTR returns a Stream which encrypts/decrypts using the AES block
// cipher in counter mode. The length of iv must be the same as [BlockSize].

}

type Sender struct {
	aead cipher.AEAD
	kem  *dhKEM

	sharedSecret []byte

	suiteID []byte

	key            []byte
	baseNonce      []byte
	exporterSecret []byte

	seqNum uint128
}

var aesGCMNew = func(key []byte) (cipher.AEAD, error) {
	block, err := aes.NewCipher(key)
	if err != nil {
		return nil, err
	}
	return cipher.NewGCM(block)
}

// defaultCipherSuitesFIPS are the FIPS-allowed cipher suites.
var defaultCipherSuitesFIPS = []uint16{
	TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
	TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
	TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
	TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
	TLS_RSA_WITH_AES_128_GCM_SHA256,
	TLS_RSA_WITH_AES_256_GCM_SHA384,
}

// defaultCipherSuitesTLS13FIPS are the FIPS-allowed cipher suites for TLS 1.3.

3DES cipher suites were removed from the default list used when
[Config.CipherSuites] is nil. The default can be reverted adding `tls3des=1` to

	iv, nonce := random[:16], random[16:]

	var aead cipher.AEAD
	switch keyType {
	case kms.AES256:
		mac := hmac.New(sha256.New, s.key)
		mac.Write(iv)
		sealingKey := mac.Sum(nil)

		block, err := aes.NewCipher(sealingKey)
		if err != nil {
			return nil, err
		}
		aead, err = cipher.NewGCM(block)
		if err != nil {
			return nil, err
		}
	case kms.ChaCha20:

		"File containing the x509 private key matching --tlsCertFile")
	c.PersistentFlags().StringSliceVar(&serverArgs.ServerOptions.TLSOptions.TLSCipherSuites, "tls-cipher-suites", nil,
		"Comma-separated list of cipher suites for istiod TLS server. "+
			"If omitted, the default Go cipher suites will be used. \n"+
			"Preferred values: "+strings.Join(secureTLSCipherNames(), ", ")+". \n"+

ecdh-sha2-nistp256
ecdh-sha2-nistp384
ecdh-sha2-nistp521
diffie-hellman-group14-sha256
diffie-hellman-group16-sha512
diffie-hellman-group14-sha1
diffie-hellman-group1-sha1
```

`--sftp=cipher-algos=...` specifies the allowed cipher algorithms. 
If unspecified then a sensible default is used.

Valid values: 
```
aes128-ctr
aes192-ctr
aes256-ctr
******@****.***
******@****.***