// SecretBox takes a message buffer, a random nonce, and a key and writes the encrypted, authenticated
// cypher text into the cypherTextOut buffer. The message buffer must have SecretBoxZeroBytes() worth
// of zero-padding at the start of it. The key may be reused across messages, but the nonce must be
// used only once for a given key. \
//
// Returns: 0 on success, non-zero on failure.
func SecretBox(cypherTextOut, message, nonce, key []byte) int {
checkSize(cypherTextOut, len(message), "cypher text output")
checkSize(nonce, SecretBoxNonceBytes(), "nonce")
checkSize(key, SecretBoxKeyBytes(), "key")
return int(C.crypto_secretbox(
(*C.uchar)(&cypherTextOut[0]),
(*C.uchar)(&message[0]), (C.ulonglong)(len(message)),
(*C.uchar)(&nonce[0]),
(*C.uchar)(&key[0])))
}
func CryptoSecretBox(m []byte, n []byte, k []byte) ([]byte, int) {
support.CheckSize(n, CryptoSecretBoxNonceBytes(), "nonce")
support.CheckSize(k, CryptoSecretBoxKeyBytes(), "key")
c := make([]byte, len(m)+CryptoSecretBoxMacBytes())
exit := int(C.crypto_secretbox(
(*C.uchar)(&c[0]),
(*C.uchar)(&m[0]),
(C.ulonglong)(len(m)),
(*C.uchar)(&n[0]),
(*C.uchar)(&k[0])))
return c, exit
}