hello everyone! first post here :D

im somewhat new to reverse engineering xiot firmware binaries, so please forgive my ignorance as i learn.

ive been working on this one embedded linux binary, but ive been having trouble. using binwalk, it cant seem to fully decompile it, only return a .lzo file. based on entropy analysis of given lzo file, it appears encrypted with partial plaintext for bootloader (high entropy/low variance, please correct me if im wrong). im not sure how exactly to go about decryption or further analysis. i thought maybe xor encryption algorithm, so i tested the binary against all possible xor encryption keys, with no results.

https://files.catbox.moe/cnre9d.bin

if anyone has the time to help out, pls do so!! ive linked a copy of the binary, if you make progress, pls let me know what you did so i can learn from it too.

thank you! ^^

I was not able to download your firmware completely (Catbox seems to be having problems today) but I can give you some tips anyway.

Step 1: It's unlikely that you've encountered a very unique hardware that has no existing tooling or documentation. Also a lot of hardware is made by the same OEM manufacturer in China and just sold under different brand names. So, use Google. Seriously. :) First few kilobytes of your firmware contain plenty of interesting and unique strings. Search for each one separately, or some combination of them. You're basically looking for the information about your hardware - CPU and system board manufacturer, addon boards, sensor information, and so on. You'll be amazed how much information a single search can provide.

You could also search for the hardware make/model (which unfortunately you didn't tell us) or FCC ID.

Step 2: Once you know the basic hardware information, use Google again. Look for tools and SDKs for the specific manufacturer/CPU. Use Google Translate to browse Chinese and Russian sites - they are a goldmine when it comes to hardware hacking and documentation. You should be able to find this github project. too. I didn't run the tool but a quick look at the source code tells me it should unpack your firmware with little to no modifications.

Step 3: Load the unpacked firmware in Ghidra/IDA and start the actual reverse engineering process. :)