Hacking Switch Private Key?

[haplesscheese]

I was trying to fuzz a .jpg for fun (to load via a microSD card to the Switch) when I found a "private" file on the card's Nintendo/Contents/ directory after the Switch configured it for storage use. On further examination, the file's contents are exactly 16 bytes long, and when viewed in hexadecimal format, appear as a unique and random string of characters - a private key, perhaps? Well, if the string is modified whatsoever, the Switch will alert the user with "This microSD card is being used by another Nintendo Switch console or was used on this console before it was formatted." This key indeed appears to be a unique identifier that is not hardware-based, with the purpose of preventing the sharing of images between Nintendo Switch microSD cards.

Now, I have two questions:
1. Is this key merely generated for the purpose of extended storage?
2. There are two files that appear in the Nintendo/save/ directory that, if modified, yield the same warning as before. Are these more checks? If so, then simply changing your friend's private key will not allow them to import images to your Switch. Only time will tell. One of them appears to be over 20 MB.

I am on firmware v4.1.0.

 

[yardie]

Do you really think Nintendo would be that careless with the private key?

Come on...

 

[isoboy]

You found the cup of christ.

 

[haplesscheese]

Do you really think Nintendo would be that careless with the private key?

Come on...

I would not think so, but I have seen how careless some companies have been (e.g. Apple and the original iPhone) when security had not been the top priority. At any rate, it is a countermeasure to prevent the sharing of microSD cards.

 

[Fishaman P]

Could be a hash of the console's unique identifier. But if that were the case, neither knowledge of what it is used for nor the value itself would be of any use to you whatsoever.

 

[smileyhead]

Interesting. I doubt those 16 bytes are the only security measure, though. Only time (and testing... lots of testing) will tell.

 

[haplesscheese]

Interesting. I doubt those 16 bytes are the only security measure, though. Only time (and testing... lots of testing) will tell.

My bad! I wrote the section on swapping private keys to view images before I discovered the other checks in the Nintendo/saves/ folder.