// SecretBoxOpen opens the authenticated cypher text produced by SecretBox and returns the original
// message plain text. The cypher text is authenticated prior to decryption to ensure it has not
// been modified from the original. The messageOut buffer must be the same size as the cypherText
// buffer and will be padded with SecretBoxZeroBytes() worth of leading zero bytes.
//
// Returns: 0 on success, non-zero on failure
func SecretBoxOpen(messageOut, cypherText, nonce, key []byte) int {
checkSize(messageOut, len(cypherText), "message output")
checkSize(nonce, SecretBoxNonceBytes(), "nonce")
checkSize(key, SecretBoxKeyBytes(), "key")
return int(C.crypto_secretbox_open(
(*C.uchar)(&messageOut[0]),
(*C.uchar)(&cypherText[0]), (C.ulonglong)(len(cypherText)),
(*C.uchar)(&nonce[0]),
(*C.uchar)(&key[0])))
}
func CryptoSecretBoxOpen(c []byte, n []byte, k []byte) ([]byte, int) {
support.CheckSize(n, CryptoSecretBoxNonceBytes(), "nonce")
support.CheckSize(k, CryptoSecretBoxKeyBytes(), "key")
m := make([]byte, len(c)-CryptoSecretBoxMacBytes())
exit := int(C.crypto_secretbox_open(
(*C.uchar)(&m[0]),
(*C.uchar)(&c[0]),
(C.ulonglong)(len(c)),
(*C.uchar)(&n[0]),
(*C.uchar)(&k[0])))
return m, exit
}