You managed to get access to the KittyCorp encryption system code! But it seems like it requires some sort of keycode in order to access the catnip storage.
Thankfully, you managed to find a test file with both an input and an output! How handy! Maybe you can use this to find the key?
By: User9684
Handout:
Flag: irisctf{s0m371m3s_bY735_4r3n7_wh47_y0u_3xp3c7}