Sorry for not having posted more frequent updates on the current work in progress.
The Lua to TNS converter compatible with OS 3.0.2 was entirely written a few weeks ago, but doesn’t yet produce valid TNS files. I had missed a few steps in the initial description of the conversion algorithm.
The constant Triple-DES keys embedded in the OS are actually used to encrypt a header, which itself includes other Triple-DES keys and an initialization vector, all uniquely generated for each TNS file created. The use of the initialization vector is quite differently than in common block cipher modes of operation. The vector is actually incremented for each 8-byte encryption/decryption step, and xor-ed with the encrypted/decrypted block.
Apparently something is still wrong or missing, but the tool is probably not far from working.
Wait, TI publicly released a month ago (or maybe was forced to release after the leak) a set of converters and documentation for Lua development. So why should we care about another converter? The official tools aren’t command-line based and require cumbersome manual steps for each code&test cycle that any developer would obviously fear. They depend on TI-Nspire Computer Software which requires a license. Many developers who bought the old Clickpad model didn’t get this license now sold with the Touchpads TI-Nspires. And most importantly Ndless 3.0 may depend on such a user tool.
Work on the awaited Ndless 3.0 is frozen as long as I cannot get the Lua converter running. I have recently quite seriously thought about making the maintenance of Ndless and related tools a full-time job, to combine free time and passion and push the project even further. Unfortunately I couldn’t find any realistic revenue model and I’m now resigned to give up on this idea…