Hello.
I’m working on an XTEA implementation and have a few questions about my mode-of-operation functions (cipher block chain). My goal is to be compatible with some of the online XTEA tools I have found; namely, something like this when set to XTEA-CBC. That tool seems to do the heavy lifting server-side, so I can’t see what’s going on, but I’d like to know how it works with keys of any length. XTEA specifies a key length of 128 bits, so maybe this tool hashes your input string to 128b and uses that checksum as the key? Also, I’m trying to figure out where to include my IV (randomly-generated) in the ciphertext, if at all, so that decryption can happen successfully.
I’m attaching my current agent and device files. Oh yeah, and I just learned of squirrel’s “>>>” operator this morning, so I need to go through and replace my bitmask right-shift hacks in the {en,de}cryptblock() functions.
It’s funny that this forum software doesn’t allow us to upload files ending in “.nut”.