Any Update on Save Decrypting?

Discussion in '3DS - Flashcards & Custom Firmwares' started by drfsupercenter, Apr 15, 2013.

Apr 15, 2013
  1. drfsupercenter
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    Member drfsupercenter Flash Cart Aficionado

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    Last stuff I saw about the topic was over a year old... and at the time, Mario Kart 7 saves still couldn't be decrypted.

    Is this still the case? It's hard to believe that nobody has worked on it at all in a year, especially now that MK7 is available in the eShop.

    I actually just ran into a weird problem, which I am not sure how to fix. A friend of mine sent me his physical copy of MK7 (I got rid of mine when I got it as a download) - he had completed it 100% and had a ton of coins... what I was going to do was backup the save file using the R4i Save Dongle, use the physical to download program that Nintendo FINALLY put out, then restore his save so we're both happy.

    But apparently as a result of the save dumper freezing up on me, it screwed up the save file. It says it's corrupted, I've tried restoring it a few times and still get that message.

    So now I fear there is no way to get his game back without starting from scratch... unless somebody has decrypted those saves, in which case I can just use one off games-engine.
     
  2. how_do_i_do_that

    Member how_do_i_do_that Blue Wizard is about to die.

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    The 3DS firmware can alter the size of the save data used by the game to a point. This is to accommodate newer games with larger save sizes. Allowing for all games to use the same save call function in the 3DS.

    One side of the problem is when you either play a game with that uses the larger save size or you update your 3DS firmware, it will automatically update all games used afterward to the new save size. I found out my zelda backup saves basically went corrupt after an system update when I tried to upload an old perfect 100% master run save.

    The other side of the problem is that the save dumper has predefined save sizes of games hardcoded into the program. Dumping saves after the 3DS game has been updated by the system means you will be missing data in the save dump.


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    The thing about the 3DS game eeprom is that it is a 8 MB of storage, while the game save data only takes up about a few KB or 1 to 2 MB of space at the most currently (Etrian Odyssey 4 uses at a minimum of 1MB for a save). This can be expanded at anytime due to a new game that uses the new save size or a 3DS update. It makes the NDS adaptor plus useless as well unless you can rewrite the code to dynamically resize future save dumps.

    Not all games will make the 3DS system use the same size if it already exceeds the minimum save size set by nintendo. Like Etrian Odyssey 4 doesn't make the system to force a 1MB save size on a game like zelda or bubble bobble. I'm still guessing how much of this done through updates etc.
     
  3. drfsupercenter
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    Member drfsupercenter Flash Cart Aficionado

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    Well, not really sure what happened with MK7 - but as a test, once it erased the save data, I did a time trial and let it save my best time, then dumped that save. It's a 512KB save file. This is with the newest 3DS update. I then restored the old one, which shows as corrupted and wipes the save data, then restored my new one and it works fine, still has the same best time.

    So apparently the R4i adapter WILL work for MK7 saves, assuming you're putting them back on the same cartridge. The problem is putting them on a DIFFERENT cartridge.
     
  4. how_do_i_do_that

    Member how_do_i_do_that Blue Wizard is about to die.

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    If your still on an old 3DS firmware, the save dump has to be de-XOR'ed decrypted and XOR'ed with the target MK7 cart. You can't transfer saves from one cart to another directly.

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    Downloaded games on a SD DON'T use XOR encryption for saves. Making your attempt at copying a failed attempt regardless of anything about the saves I tell you.
     
  5. drfsupercenter
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    Member drfsupercenter Flash Cart Aficionado

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    Yes, I know they have to be decrypted and re-encrypted.

    What I'm asking is if that's possible.

    As far as the download goes... Nintendo has that tool now to convert your retail saves to download saves, which is precisely what I am trying to do. Since my friend had 100% completed his game, I was hoping to just use his save for mine, you see? But for some reason the dumping process screwed up the save and made it show as corrupted.

    For download games on the SD, the saves are still encrypted though, aren't they? Just with a unique identifier so that you can't share them with people - similar to what the cartridges use I thought. Or am I wrong?
     
  6. how_do_i_do_that

    Member how_do_i_do_that Blue Wizard is about to die.

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    It is not the same encryption. That would be a phat NO when your dealing with downloaded games and real carts of the same game.
     
  7. drfsupercenter
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    Member drfsupercenter Flash Cart Aficionado

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    Can you swap saves with someone else who have the same downloaded game? As in, is there a way to decrypt and re-encrypt those?

    Anyway, I think you're missing my point here. Nintendo has a tool now that lets you transfer saves from your real cart to the download version. IT does the conversion for you. All I need is the ability to put *a* save back on this physical MK7 cart so I can use that tool. You see? So what I'm asking is if there is a way to use someone else's save yet on a physical cart.
     
  8. how_do_i_do_that

    Member how_do_i_do_that Blue Wizard is about to die.

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    Unless the R4i Save Dongle supports the new save size your 3DS is using, your only going to be dumping a partial save (meaning it will be corrupt every time you try and dump it).

    You would have to have dumped the save PRIOR to you sticking the MK7 cart into your 3DS to transfer the save. There is little guarantee that restoring the pre save size change will overwrite the post save size data change on a real cart, as in what I talked about with my zelda saves in my first post.

    You were likely screwed the moment you went and stuck that MK7 cart of your friend in your 3DS.



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    If you haven't figured out by now, Nintendo doesn't like people sharing ANYTHING if it wasn't authorized by them in a prescribe manner that they dictate. Game save data being one of them.
     
  9. drfsupercenter
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    Member drfsupercenter Flash Cart Aficionado

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    Um... like I said, it works just fine... it gives me a 512KB save file - and I can confirm that it DOES do it right. If I put a save I downloaded from the saves website on, it will show as corrupted and erase the save data. I can then restore the new save I dumped that has time trial data and it shows up just fine. I haven't used the tool yet.

    All I need to know is if I can decrypt a save made from another retail MK7 cartridge and re-encrypt it for my friend's.
     
  10. how_do_i_do_that

    Member how_do_i_do_that Blue Wizard is about to die.

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    restoring a prior save to the same cart doesn't need decryption.
     
  11. drfsupercenter
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    Member drfsupercenter Flash Cart Aficionado

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    Right. Except that for some reason his 100% save got screwed up when dumping so I don't have a valid save file. I need to decrypt one from ANOTHER cart to put on his.
     
  12. how_do_i_do_that

    Member how_do_i_do_that Blue Wizard is about to die.

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    I gave the answer via every situation so you come to your own conclusion on the matter but you haven't summed it up for yourself.

    NO VALID SAVE DUMP = YOUR SCREWED.


    Anymore simpler, it will be in binary.




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    The comment about game save size changing seems to apply to certain games with DLC, likely to adjust for any data the game didn't want saved to the SD. And the zelda issue of mine is due to me writing to the wrong copy of my game.
     

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