CookieRun OvenBreak sequenced music files (.mid) by kookeerawn at 9:17 PM EDT on May 7, 2020
The MIDI files in CookieRun OvenBreak can be playable in-game, but not in the MIDI player. I tried swapping a regular MIDI file (flourish.mid for example) into the game, but the game couldn't play that song.
Maybe the CROB MIDIs are encrypted and they're probably FSB files in disguise in which they contain original MIDI files. Each MIDI file in CROB starts with the number 7. The number 7 might be the first letter of the password.
Can you please help me on decrypting all the MIDI files in CROB?
These are raw MIDI files which are just scrambled using the same pattern for every file. The "7" you mentioned is a scrambled "M" from "MThd". The first 10 bytes (header except delta value) and offsets 14 to 19 (first track header including 2 zeros of track length) are always identical. Those constant bytes can be used to de-XOR a few values but they're not enough to derive a clear scramble pattern.
If the game holds a copy of a complete de-scrambled MIDI file in RAM, it can theoretically be used to generate the scrambling pattern.
Good news on that, actually! https://drive.google.com/drive/folders/1g9Ja2Su3dqyecsndss-k4uJ6vutcoGZy?usp=sharing a while ago, 4 midi files released unencrypted, so we could use these to decrypt the rest of the midis?
Just a tiny experiment: they seem XORed. Results for concordant files (i.e "same" starting bytes, same filesize). This is thanks to you. So, there must be a KEY file somewhere, because KEY does not cover entirety of .MID files.