Homebrew [Coming Soon] OTPless A9LH installation on N3DS (no 2.1 downgrade)

[dark_samus3]

slightly off topic, but how do you even go about finding your own vulns?

learn to code, then learn low level programming, then learn how to reverse engineer. After all that:
1. Reverse lots and lots of code
2. stare at reversed code
3. investigate areas that look interesting
4. determine if interesting areas are exploitable
5. ???
6. profit (or don't, if it was un-exploitable)

If you understand low level things, you'll likely understand how one might take code down a path it was never intended to have. If you really like, start with some simple buffer overflow tutorials

in this case, I actually didn't need to do any RE, as this just builds off of the arm9loaderhax flaw, and is a rather simple data manipulation

 

[Urbanshadow]

is it really? it only works on already exploitable systems and just makes something currently easy a bit easier.

In terms of difficulty, pwning the arm11 sandbox to grant arm9 control is way harder, but chaining exploits to grab a boot time locked, cryptographic sensible data (otp) in such a beautiful and simple way shreds the whole arm9loader security investments to pieces.

This thing here nullifies any extra effort besides of arm9 control (yeah, that may be not much, but still) to fully pwn the hardware boot process, until it gets patched.

What I was trying to say is that right now, downgrading to 2.1 for N3DS systems (the riskier ones) could become useless.
This narrows the whole a9lh process to just having downgrade access to 9.2 or direct access to arm9 code execution.

And by my understanding, if carefully done could be way safer than a downgrade+update process, even with ctrnand backups.

 

[nooby89]

And on O3DS ?

 

[KunoichiZ]

And on O3DS ?

For the last fucking time, this won't work on a o3DS. Learn to read previous posts in a thread.

 

[nooby89]

Nice.

 

[dark_samus3]

For the last fucking time, this won't work on a o3DS. Learn to read previous posts in a thread.

Or, you know, original post

 

[SciresM]

In terms of difficulty, pwning the arm11 sandbox to grant arm9 control is way harder, but chaining exploits to grab a boot time locked, cryptographic sensible data (otp) in such a beautiful and simple way shreds the whole arm9loader security investments to pieces.

This thing here nullifies any extra effort besides of arm9 control (yeah, that may be not much, but still) to fully pwn the hardware boot process, until it gets patched.

It's not patchable -- Nintendo can't revoke the firmware file they signed, and this works by writing that firmware to NAND.

This will always be possible so long as you have arm9 code execution.

 

[dark_samus3]

It's not patchable -- Nintendo can't revoke the firmware file they signed, and this works by writing that firmware to NAND.

This will always be possible so long as you have arm9 code execution.

They could do some nasty tricks, but it really wouldn't be worth it for them at this point

 

[VinsCool]

I don't even understand why people keep asking for o3ds. It's less likely to brick on 2.1 anyway.

 

[swnny]

Maybe a bit of a noob question, but I'll ask anyway. (its not about o3DS! )
I've being using 9.2 menuhax + emunand for months now on my NEW 3DS and all my installs, saves, etc are on emunand. With this OPTless method/tool I no longer have an excuse to not install A9LH. Question is, would it be possible, and how, to migrate all my stuff from emunand to a9lh'ed sysnand?

 

[linuxares]

Nice work @dark_samus3 ! Props to you and all the people that helped!

To the people that are looking for this, I say as I always said to people that wish to hack their 3DS. Wait for the guide to update!!!!

 

[jimmyleen]

Any version with an arm9 exploit works

it's still only for those on 9.2 or below/those who can downgrade to 9.2.

 

[moghedien]

Question is, would it be possible, and how, to migrate all my stuff from emunand to a9lh'ed sysnand?

https://github.com/Plailect/Guide/wiki/Move-RedNAND

 

[capito27]

They could do some nasty tricks, but it really wouldn't be worth it for them at this point

short of blocking memory access to the landing area of the jump from arm9, they can't really, from the code i read, Key0 is used in place of Key0 (if i read right), which is used to generate other keys, so it would be annoying for them to poison the key and handle the weird cases where people reboot or shutdown mid update, they won't do that then. they won't be preventing to overwrite to firm0/1 from arm9...because that would be kinda stupid and inf not impossible, pretty close to it.
the magic of OTPless a9lh install process, is that at the end it only relies on 3 modifiable things : firm0 partition to be replaced with 10.0 NFirm, secret keysector 1 to be replaced by key in slot 0 (if i read right the code) and to be able to setup arbitrary memory which will survive a reboot.
The first requirement, we can take it for granted, as arm9 kinda has full access to nand memory, so there's that.
the second requirement, as i said earlier, short of poisoning the key we use to trigger the initial otpless jump, they can't do much about
the last requirement, i would be tempted to say that there is no way to change the logic of the mcu reboot to not clear arm9 memory, but they already updated mcu firm in the past, so we never know, but i'd say that if they were to fix otpless, they'd go for 3, as it would be the safer to implement imo.

but do they really wanna go all the way to simply slow down a9lh install ? because they can't really FIX future a9lh install, since the old method is kinda... unpatchable in software only form.

 

[dark_samus3]

short of blocking memory access to the landing area of the jump from arm9, they can't really, from the code i read, Key0 is used in place of Key0 (if i read right), which is used to generate other keys, so it would be annoying for them to poison the key and handle the weird cases where people reboot or shutdown mid update, they won't do that then. they won't be preventing to overwrite to firm0/1 from arm9...because that would be kinda stupid and inf not impossible, pretty close to it.
the magic of OTPless a9lh install process, is that at the end it only relies on 3 modifiable things : firm0 partition to be replaced with 10.0 NFirm, secret keysector 1 to be replaced by key in slot 0 (if i read right the code) and to be able to setup arbitrary memory which will survive a reboot.
The first requirement, we can take it for granted, as arm9 kinda has full access to nand memory, so there's that.
the second requirement, as i said earlier, short of poisoning the key we use to trigger the initial otpless jump, they can't do much about
the last requirement, i would be tempted to say that there is no way to change the logic of the mcu reboot to not clear arm9 memory, but they already updated mcu firm in the past, so we never know, but i'd say that if they were to fix otpless, they'd go for 3, as it would be the safer to implement imo.

but do they really wanna go all the way to simply slow down a9lh install ? because they can't really FIX future a9lh install, since the old method is kinda... unpatchable in software only form.

There's an easy trick they could do. New arm9loader which re-encrypts the secret sector with some encryption mode other than ECB the keys stay the same, OTPless goes away, if you update beyond a certain point, anyways

 

[Clector]

Yes, but I guess they may like to first try to work in patch the DSiWareHaxx Nand dump and restore since that let people downgrade.

 

[PaiiNSteven]

I just bought a DSi cart like two minutes ago. What the fuck.
In all seriousness this is awesome progress! Nice job guys!

 

[Redirr]

Yes, but I guess they may like to first try to work in patch the DSiWareHaxx Nand dump and restore since that let people downgrade.

Hope you guys could use this otp less in 11.0 FW pachted with DSiwarehaxx. So i dont need to downgrade to 9.2 anymore...

Ive been doing some downgrade service here and i bricked a new 3ds downgrading from 11.0 to 9.2.

I didn't try otpless yet. Im very scare at momento. But i wanna try it soom. Hope its envolve to a 11.0 pachted FW for no need to downgrade.

 

[PaiiNSteven]

Will we be able to get the OTP without dging? There was a theory to get it on 9.6 when it loads into the cache, can we do this instead of dging all the way to 2.1?

 

[SciresM]

Will we be able to get the OTP without dging? There was a theory to get it on 9.6 when it loads into the cache, can we do this instead of dging all the way to 2.1?

No.