Hacking Question Resign USER.bin using HacDiskMount?

[Advanced User]

I decrypted the USER.bin from the emummc of my defective Switch using HacDiskMount and Bis Key 3.
So I can now mount and browse it. As an experiment, I'd like to resign the decrypted USER.bin with the Bis Key 3 of a new Switch, so I can inject it into the new emummc. It would be great if this worked, because then I wouldn't need to reinstall any games and I would keep my saves.

Does anyone know how?

 

[Hayato213]

No, NAND backup and Bis_key are console specific, you can't use one key with another console.

 

[Advanced User]

I wish to resign the decrypted bin with the keys of the NEW console.

Is it really that hard to understand? It's decrypted now. No more encryption.
I now would like to re-encrypt it, but not with the old bis key 3, but with one from a new Switch.

Next I would create an emunand backup of said new switch, delete the USER directory and replace it with the one encrypted with the new key.

 

[ZachyCatGames]

You can, but there's really no point and it wouldn't accomplish what you want.
Saves are signed with device unique keys and you'd have to reinstall everything anyway because that content wouldn't be in your app records and content db, and you wouldn't have etickets for that content.

 

[Advanced User]

Thank you for your explanation, I was afraid there'd be a database, too.
But from what I've read, it seems at least possible to extract saves and transfer them to a new Switch?
https://gbatemp.net/threads/extract-save-from-nand-backup.514261/#post-8299285

And this post (you also posted in that thread) https://gbatemp.net/threads/importi...h-with-backup-nand.523551/page-2#post-8615479

Unfortunately no detailed explanation.

 

[ZachyCatGames]

Thank you for your explanation, I was afraid there'd be a database, too.
But from what I've read, it seems at least possible to extract saves and transfer them to a new Switch?
https://gbatemp.net/threads/extract-save-from-nand-backup.514261/#post-8299285

And this post (you also posted in that thread) https://gbatemp.net/threads/importi...h-with-backup-nand.523551/page-2#post-8615479

Unfortunately no detailed explanation.

You can, yeah, but it requires a bit of work. You can resign them with hactoolnet, but I'm unsure if that'd "just work". Or you could extract all the saves, figure out what each save is for, and restore them with whatever save manager.

 

[Advanced User]

I'm quite sure it wouldn't work to just resign them the way they are and simply paste them into the new save folder, because like the games the saves wouldn't be in the database. Since there's no automated tool to identify them, it would be a crazy amount of work to find out which is which and then to convert them to Checkpoint's format one by one, so I won't be doing this.
I do have a Checkpoint backup of everything from a few months ago, and Checkpoint saves of my most recently played games, so I'm not losing a huge amount.
Before my old Switch became defective, I didn't look into this; I incorrectly assumed there'd be simple methods to extract and transfer saves from one emuMMC to the other by now.
The lesson here: Back up all your saves occasionally. Shame that Checkpoint isn't getting updated anymore (yes, I know someone created a fork that works on firmware 12.x, which is what I am using). Guess I'll check out JKSV next.

Have a great day!