Opening a .IOP File

LepEatWorld · 10/30/2019, 04:08

So, I currently tried to open an IOP file but for some reason I cant seem to you know... get it open. I'm able to open it as a Zip, but if I do the file contains 0bites. When I open it with Notepad++ it's kind of encrypted? Not sure at this point. But when I open it with

it shows me the files inside and then it stops and shows me the Zip files instead...

This is an example of the files that should be inside the IOP.

Spoiler

Thanks for the help in advance to whoever can help.

elmarcia · 10/30/2019, 21:51

Quote:

Originally Posted by LepEatWorld

So, I currently tried to open an IOP file but for some reason I cant seem to you know... get it open. I'm able to open it as a Zip, but if I do the file contains 0bites. When I open it with Notepad++ it's kind of encrypted? Not sure at this point. But when I open it with it shows me the files inside and then it stops and shows me the Zip files instead...

This is an example of the files that should be inside the IOP.

Spoiler

config/accessory/bracelet/000_bracelet_buff.ini
config/accessory/bracelet/000_bracelet_buff_accessory.ini
config/accessory/bracelet/000_bracelet_buff_normal.ini
config/accessory/bracelet/000_bracelet_item.ini
config/accessory/bracelet/000_bracelet_skill.ini
config/accessory/necklace/PK config/accessory/necklace/000_necklace_attack.ini
config/accessory/necklace/000_necklace_buff.ini
config/accessory/necklace/000_necklace_buff_accessory.ini
config/accessory/necklace/000_necklace_buff_normal.ini
config/accessory/necklace/000_necklace_item.ini
config/accessory/necklace/000_necklace_skill.ini

Thanks for the help in advance to whoever can help.

Code:

import zlib
import os

f = open("rs.iop","rb")

#zlib header
pkHeader = b"\x50\x4b\x03\x04"

print("Unpacking...")

while True:
    header = f.read(4)
    if header != pkHeader:
        break
    filenamelen = int.from_bytes(f.read(1),byteorder="little")
    #skip bytes
    f.read(0xD)
    filesize = int.from_bytes(f.read(4),byteorder="little")
    #skip bytes
    f.read(8)
    filename = f.read(filenamelen).decode("utf-8")
    if filesize == 0:
        try:
            os.mkdir(filename)
        except:
            pass
    else:
        fo = open(filename,"wb")
        print(filename)
        data = f.read(filesize)
        try:
            decompressed = zlib.decompress(data,-15)
            fo.write(decompressed)
        except:
            #can't uncompress data, write plain
            fo.write(data)
        fo.close()

f.close()

print("Done!")

LepEatWorld · 10/31/2019, 13:01

Thanks for the help, haven’t tested it yet since I havent had time but I’ll check it tomorrow after Halloween �� Thanks again.

elmarcia · 10/31/2019, 15:22

Np, if you need to pack it again will need to figure out unknown bytes, i assume 4 of them is for CRC the file name len is 2bytes not 1 like i said, but used one cause max path is 255. And make a script for the reverse process.