public static byte [] DecodeData(byte[] data, int offset, long size)
{
#if MULTI_ENCODING
Encoding enc = GetEncodingOfData(data);
// LogUtil.TraceFormat("data {0} {1} {2} {3} {4} {5}", data[0], data[1], data[2], data[3], data[4], data[5]);
if (enc == Encoding.Unity)
{
return(data);
}
if (size < 2)
{
throw new Exception("BundleEncoder DecodeData invalid size " + size);
}
// FIXME
// Using returned (unsigned char *) as byte [] crashes
// Currently have to copy data for all
byte[] buf = new byte[size - 2];
Array.Copy(data, offset + 2, buf, 0, size - 2);
if (enc == Encoding.Plain)
{
return(buf);
}
else if (enc == Encoding.Rc4)
{
LuaDLL.arc4_decrypt_easy(buf, 0, buf.Length,
LBootApp.BUNDLE_IV, LBootApp.BUNDLE_IV.Length);
return(buf);
}
else if (enc == Encoding.AES_256_CBC)
{
byte[] temp = new byte[LBootApp.BUNDLE_IV.Length];
Array.Copy(LBootApp.BUNDLE_IV, temp, LBootApp.BUNDLE_IV.Length);
LuaDLL.aes_256_cbc_decrypt_easy(buf, buf, 0, buf.Length,
LBootApp.BUNDLE_KEY, LBootApp.BUNDLE_KEY.Length,
temp, temp.Length);
return(buf);
}
else if (enc == Encoding.Chacha20)
{
byte[] outbuf = new byte[buf.Length - 16];
int res = LuaDLL.crypto_secretbox_open_easy(outbuf, buf, buf.Length,
LBootApp.BUNDLE_NONCE, LBootApp.BUNDLE_KEY);
if (res != 0)
{
throw new Exception("BundleEncoder Chacha20 decode return: " + res);
}
return(outbuf);
}
else
{
LogUtil.WarnFormat("invalid encoding of bundle data: {0} {1} (probably not encoded)",
data[0], data[1]);
return(data); // try to read as is
}
#else
return(data);
#endif // MULTI_ENCODING
}
