Help extracting files from encrypted 3DNUS .cia

Discussion in '3DS - ROM Hacking, Translations and Utilities' started by ubergeek77, Apr 10, 2015.

  1. ubergeek77
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    ubergeek77 Post editing world champ.

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    This is driving me absolutely nuts.

    All I want to do is extract a few files from the System Menu title, which I have downloaded using both 3DNUS and UpdateCDN (I had hoped one of them would give me a decrypted file). The resulting .CIA file is encrypted, and I can't do much else with it from there. I've used just about every conversion tool and 3DS utility I can get my hands on, but it's apparent I'm not clear on what needs to be done to decrypt this thing. I know this is possible (and arguably quite easy), but this encryption has me stuck against a wall. Normally you would install the .CIA and use SDinfo.py to help you generate the xorpads, but as this is a system file, I cannot use this method. The answer must be simple...right?

    TL;DR Please help me get romfs.bin (or just the files within it) out of an encrypted .CIA (or if there is some easy way to use rxTools to dump this from the system titles on my NAND, that works too).

    Thanks.
     
  2. Arkansaw

    Arkansaw GBAtemp Advanced Fan

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    rxTools is able to dump system titles, but not fully unpack them

    if you get a .app file you might need to get xorpads for the contents within it using the multi decryptor, to further unpack them
     
  3. mid-kid

    mid-kid GBAtemp spamBOT

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    Just a wild guess: install it on any emuNAND, dump the fat16 contents of said NAND, look for the titleID of the System Menu just like you would in the Nintendo 3DS folder of your SD card, and copy the files you find somewhere else. They should be decrypted, as the fat16 partition of the NAND rarely contains encrypted stuff AFAIK (just checked extdata for playcoins though :P).
     
  4. SciresM

    SciresM GBAtemp Advanced Fan

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    You need the decrypted titlekey, which requires installing it and then using one of the several decrypted titlekey dumpers available (there's one in rxTools). But rxTools also has a "Dump system titles from NAND" thing, so that might be more convenient for you.