Resurssiklunssi exploited to decompress RCO images

[qwikrazor87]

If you've used Resurssiklunssi to decompress your RCO files then you probably know that the images in the RCO files are decompressed and recompressed using zlib. Through the normal process of using the mentioned homebrew the RCO is decompressed but the images remain compressed. For a while I've been wanting to look at the uncompressed icon images and I finally found a way to decompress them on my PSP with the mentioned homebrew. In an official RCO, the header, table and data sections are packed separately. After running the RCO through the homebrew the header is left decompressed while the image icons aren't. That's where the idea came to mind. I replaced the header with a compressed icon and changed some values then ran the homebrew and now I have the original uncompressed GIM images. I know that it's illegal to distribute RCO files so I'm not sure if I'm able to distribute the GIM images, so I'll have to wait for one of the moderators word on it. These GIM images can be useful for anyone wanting to use them for CTF themes. I found out that the main icons are in GIM format and the shadow icons are in TGA format. I just wanted to share what I found out. Sorry for the wall of text. >_<

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