Sighax for dummies: An FAQ for the rest of us.

Discussion in '3DS - Homebrew Development and Emulators' started by icefire82G, Apr 25, 2017.

  1. icefire82G
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    icefire82G The Sighax FAQ Guy

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    7/22/17: Thread is temporarily dead. I'm in the process of a new writeup, but since Life™ is a bitch, it's not going to be for a while. I haven't forgot about this, I've just been busy. Thanks for your patience!

    5/29/17: Just a quick FYI for people who are just tuning in: B9S is the SAME THING as Sighax. Derek's installer and B9S are just different implementations of Sighax. Also, updates are coming Soon™.


    We're all in one of a few boats right now. You're either one of the people who accidentally updated to 11.4 without custom firmware, a developer who wants even more power, a pirate who wants to get their hands on all of the games on all of the platforms, or a complete newbie who just wants to impress their friends.

    So you've come to GBATemp's 3DS Homebrew forum, and you see some stuff about this "sighax" thing, and open up a thread to find technical jargon way above your head (unless you're a dev, of course). After looking around, you probably have found very little that's in the "user friendly" side of this exploit. Well, worry no more! Because Sighax for Dummies is here to try and answer all your questions!

    Remember to check back on this post frequently for updates, as I'll try to be as efficient with updating this post and answering questions as I can.

    1. So what the heck is a sighax?
    Sighax is an exploit discovered by derrek, where he used a dumped copy of the bootrom in order to have every custom firmware be read as valid during the verification part of the 3DS power-on sequence.

    2. Woah woah, slow down. Tell me what this "bootrom" is!
    A bootrom is a piece of code burned into the system-on-chip, a little circuit that integrates all the necessary hardware for an electronic device to run. In the case of the 3DS, it has the processor, the bootrom, and a few other electrical things that, for this thread, don't matter too much. The bootrom is a teeny tiny piece of code stored in a tiny rom chip in the SoC that provides some basic encryption keys that validate the NAND, and other system components, and then allows for the 3DS to turn on.

    3. Why would we need to mess with that?
    At first, it was so we could get at one of the encryption keys used to decrypt 3DS games, but while trying to get this key, we managed to find the bug that allows us to use the sighax exploit on pretty much any 3DS family system, allowing us to run any custom firmware as if it were made by Nintendo themselves.

    4. So what can we do with it?
    It can do pretty much anything a9lh can do (including the "true firmwares" everybody's on about), but can be installed with dsiware hax or a hardmod, which is easier than having to downgrade to 2.1.0 in order to grab the console-unique keys from the OTP, as well as being fix-proof by any system updates. Additionally, if you're of the developing type, the execution environment will be cleaner for you too.

    5. Does that mean my 3DS is safe to update?
    Technically, yes! Since Sighax is out now, you'll be able to install it on 11.4 and up! Go ahead and update, friendo, you're in the clear. Just remember, you'll need a second 3DS with CFW already AND a copy of one of the dsiware games listed on the Holy Guide (3ds.guide), in order to fully be able to install sighax. Or, if you already have a9lh, dsiwarehax, or a hardmod on the system you want to sighax, you can just use those to directly install sighax! Ain't that neat!

    If you're still on 11.3 or below, and you don't own a dsiware hackable game, and you still want sighax, just go ahead and install a9lh through soundhax or some other homebrew entry point, and then upgrade to boot9strap after that. It saves time AND effort!

    6. When do we get it then?
    It's here now! Check 3ds.guide for instructions on how to install sighax with an already implemented a9lh setup (upgrading to b9strap), or without that (the normal guide)!

    7. Why won't we get the bootrom?
    Previously, it's because that would be illegal, because the bootrom is copyrighted code, and unleashing it upon the internet is a pretty major crime. Now, sighax will allow you to dump your own bootrom! You probably won't need it, unless you're gonna do a bit of tinkering, especially since all the necessary keys are just out there on the internet now. Happy hunting!

    8. So what now?
    You get out there, and you get sighax now! Because pretty much everything from this point onward will require it, and it's better to get it early than later.

    So that's about it for what you need to know about sighax. If you want to know anything else, you should ask about it on the discussion thread, hedge's stream, or even here, and somebody will probably answer it.

    changelog
     
    Last edited by icefire82G, Jul 22, 2017


  2. icefire82G
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    icefire82G The Sighax FAQ Guy

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    SIGHAX PROBLEMS? LOOK NO FURTHER THAN HERE!

    Updating Luma bricked me! Why?

    That's cause the newest update for Luma doesn't have any a9lh payloads anymore! You'd have to have updated to sighax before updating for it to actually work. If you redownload 7.0.5 and put it back at the root of the SD card, and you should be good to go!

    WIL SIGHAX BRIK MY DS???????

    Short answer: Nah, you should be fine.

    Long Answer

    More will surely come soon, as problems arise...
     
    Last edited by icefire82G, Jun 26, 2017
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  3. maorninja

    maorninja GBAtemp Fan

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    Why don't you ask the OP of the Sighax discussion page to put this in his page?
     
  4. Quantumcat

    Quantumcat Dead and alive

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    Don't we already have a thread for this?
     
  5. maorninja

    maorninja GBAtemp Fan

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    No, the other thread is for discussion, while this is a FAQ.
     
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  6. icefire82G
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    icefire82G The Sighax FAQ Guy

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    That's a lot more of a discussion thread kind of thing, and the FAQ/information on that is pretty hard to understand, especially if you're new to this sort of thing and are wondering what the heck's going on.
     
  7. Quantumcat

    Quantumcat Dead and alive

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    There is a FAQ in the OP.
     
  8. icefire82G
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    icefire82G The Sighax FAQ Guy

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  9. Lucar

    Lucar Professional Ferret

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    Close, it's not a chip, it's code that is permanently written into the processor itself. Also, the bootrom does very little in the actual boot process (sets up a few keys and initializes some hardware) and then hands a lot of things over to other things like arm9loader.
     
  10. Quantumcat

    Quantumcat Dead and alive

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    You should probably ask the OP of the main thread to add your content to the FAQ rather than making a whole new thread.
     
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  11. GerbilSoft

    GerbilSoft GBAtemp Addict

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    Please fix this section. Literally the only main advantage to sighax is the ability to install it without OTP (e.g. via DSiWareHax or hardmod). Boot time difference is negligible (on the order of milliseconds). Custom firmware and OS is already possible today, but no one is willing to spend the effort to write a clone of the 3DS OS. (There is a preliminary port of Linux: https://gbatemp.net/threads/release-linux-for-the-3ds.407187/)
     
  12. addi33

    addi33 GBAtemp Advanced Maniac

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  13. icefire82G
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    icefire82G The Sighax FAQ Guy

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    should be fixed now, let me know if anything else is wrong, because I want this to have the most accurate info possible!

    I'm not entirely sure what "OTP" is, but hopefully I should have fixed that section. Thanks for telling me!

    thanks for linking to the writeup, however, i'm still going to try and keep this thread as more of a newbie discussion, as a lot of the stuff that goes on in your thread would be pretty complicated to a newbie (and I should know, because I was in that position once. i'm just a fast learner). though f you have any suggestions as to how i can improve this, i'm all ears! i just don't intend to let this thread die without a fight
     
  14. Quantumcat

    Quantumcat Dead and alive

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    "Newbie" discussion is really going to be the same couple of questions over and over again - there isn't really anything to discuss for newbies. The FAQ is in the OP to answer the common newbie questions, with the discussion for people who know enough to express opinions on it. Newbies won't have anything to discuss if they don't understand what it is.
     
  15. Lucar

    Lucar Professional Ferret

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    Sighax stands for nothing, it's a name on it's own. Also, Sighax itself is not the exploit used to dump the bootrom, it's a exploit within the bootrom's code that allows us to make the 3DS think that any firmware created is signed by nintendo, when in reality, they aren't. Fault Injection was the "exploit" used to help dump the bootrom.

    Originally, it was because we wanted keys that only the bootrom has, such as a certain key (of which I forgot the name right now) that would allow us to decrypt games without the 3DS. But, then, thanks to an FCC document stating that the "security function of the initial program loader" on the 2DS had changed between different models. So, derrek was like "Oh hey, there's probably a bug then" and, well, they found one. Ironically, the bug exists on all 3DS family systems, so whatever Nintendo fixed was not sighax. Also, your last statement is false, even with sighax, there will be a need to escalate to most likely ARM9 kernel for dumping of the bootrom to allow installation.

    You shouldn't be telling people on 11.3 without CFW to update, ever. Tell them to follow 3ds.guide, please.

    As I said above, you're probably going to need to dump the bootrom, so there will be need for privilege escalation of some form. Also, A9LH itself is already unpatchable, so your 'unpatchable point' has no purpose.

    Please, do your reasearch before making a post like this next time, and also a note: If what you're saying is flat out wrong, even if it's easier for newbies to understand, was it worth teaching if afterwards they'll learn that what they were told was wrong?
     
    Last edited by Lucar, Apr 26, 2017 - Reason: damn numbers
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  16. GerbilSoft

    GerbilSoft GBAtemp Addict

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    I said that DSiWareHax and/or hardmod can be used to *install* sighax. What isn't needed is the OTP ROM, which is currently required for A9LH.

    ...have you actually installed A9LH yourself, or even read https://3ds.guide/ ? The OTP ROM is required for A9LH, and is the entire reason why the 2.1 downgrade is needed. (That's what otp.bin is.)
     
  17. addi33

    addi33 GBAtemp Advanced Maniac

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    Your are wrong. SigHax is short for SignatureHax. SigHax is a bootrom exploit that allows us to sign nand images using fake crafted keys. The exploit that is used to dump prot_boot9.bin is not SigHax at all, thats Vector-Glitchhax.

    Please, do your reasearch before making a post like this next time,.
     
  18. icefire82G
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    icefire82G The Sighax FAQ Guy

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    Fixed. I did as much research as I can, but I don't understand too too much of it, which is, again, the whole reason for making this post. People who try to look this up, who are new to custom firmware installation, probably won't understand too much. It's also why I said to check back for updates, because I figured there would be inaccuracies, because again, I don't understand much either. I might as well try to teach to the best of my ability, rather than not teach at all, if it will be able to help somebody understand slightly more.

    I installed it on an o3ds a little while ago, and followed the instructions to a T. When I installed it, I pretty much just carefully did what the guide said, without looking into what each component of it was, mostly because I wanted to get it to work before I tried to understand it, which is pretty much why I joined GBATemp, to understand this, and learn what everything is.
     
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  19. Lucar

    Lucar Professional Ferret

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    You just repeated what I said in different words. And, fine, call sighax whatever you want. :P

    Also, I can't tell if the end part is sarcasm (assuming it is, because it's evident that you copy-pasted it from my post), but I hope you understand I wasn't mad at OP, I'm just frustrated by the fact that people who genuinely want a simple explanation for sighax were going to get incorrect information.

    You OK with that? Good. GOOD. GOOD. *insert badly autotuned mario kart 8 music* please, someone get the reference
     
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  20. hurrz

    hurrz GBAtemp Regular

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    What does OTP mean? It is also mentioned in 3ds.guide but I could not find anything. I would appreciate an answer and thougt this would be the right thread to ask that kind of question.
     
    Last edited by hurrz, May 10, 2017