Method encryptTicket

ticket.go:325–351

(state []byte, ticketKeys []ticketKey)

}

func (c *Config) encryptTicket(state []byte, ticketKeys []ticketKey) ([]byte, error) {
	if len(ticketKeys) == 0 {
		return nil, errors.New("tls: internal error: session ticket keys unavailable")
	}

	encrypted := make([]byte, aes.BlockSize+len(state)+sha256.Size)
	iv := encrypted[:aes.BlockSize]
	ciphertext := encrypted[aes.BlockSize : len(encrypted)-sha256.Size]
	authenticated := encrypted[:len(encrypted)-sha256.Size]
	macBytes := encrypted[len(encrypted)-sha256.Size:]

	if _, err := io.ReadFull(c.rand(), iv); err != nil {
		return nil, err
	}
	key := ticketKeys[0]
	block, err := aes.NewCipher(key.aesKey[:])
	if err != nil {
		return nil, errors.New("tls: failed to create cipher while encrypting ticket: " + err.Error())
	}
	cipher.NewCTR(block, iv).XORKeyStream(ciphertext, state)

	mac := hmac.New(sha256.New, key.hmacKey[:])
	mac.Write(authenticated)
	mac.Sum(macBytes[:0])

	return encrypted, nil
}

// DecryptTicket decrypts a ticket encrypted by [Config.EncryptTicket]. It can
// be used as a [Config.UnwrapSession] implementation.