Using a Common Key (Wii U)

What is a Common Key for?

The common key is a key in hexadecimal that is the main way of decrypting things. Every Wii U has a unique one that can't be changed or modified in any way. It is located in the OTP.bin you are supposed to save once you've made the backup to all your important files.

How come it is that important?

Well, as said before, it is one of the many keys used to decrypt console files. If you find any way to modify it, you're basically locked out with the wrong key to decrypt your console's contents which means you got a hard brick. That can't be recovered. The OTP is a 1024B file that contains all the keys to your Wii U console.

Where is that key located on the motherboard?

The OTP (One Time Programmable key) is located in the SoC (System on a Chip) of the console which somehow is easily replaceable but you can't write to it... Thanks, Nintendo.

Any other things I should be aware of?

In a short way, yes. In a long way, there are multiple other part of the SoC like the SEEPROM, SLC, SLCCMPT and things like that.

In my knowledge, the SLC, SLCCMPT and maybe SEEPROM is writable. There's also the MLC but it is not part of the SoC. It is part of the NAND.

Why would I need this key?

Why? Because, for some tools that don't already have a self extracting tool to get your Common Key when redownloading for exemple, System Files (I'm watching you JNUSTool), it can be useful to have it!

Here's non-exhaustive list of all the software that uses the Common Key:

UWUVCI - Useful for making Wii Virtual Consoles Injects
JNUSTool - Useful for redownloading system files

(yes I only got 2 in mind)

But, I don't know how to extract/get it!

Calm down. There are 3 main ways for you to get the Common Key.

Use GaryOderNicht's tool (Windows only)
Use Acer51's tool (Windows, macOS and Linux)
Manually.

GaryOderNicht's tool

To use GaryOderNicht's tool, when you open the app, you must click on the Open button, go too the location where your OTP.bin is, select or double click it and your Common Key will appear.

Acer_51's tool

To use Acer_51's tool (acer51-doctom on GitHub), it depends on the platform you are on.

Windows

Double click the executable. In an explorer window, drag and drop your OTP.bin into the Command Prompt window. You can also manually enter the path to it. Then, press Enter. Once you are finished, press Ctrl+C to quit. It will NOT automatically copy and paste.

macOS / Linux

To execute it, you must open a Terminal window in the same directory as the executable. Then, you must execute this:

chmod +x commonkey_extractor && ./commonkey_extractor

What does this do? Well, the chmod +x is to make something executable and so that you "own" it. && means to do something after this is done. and ./commonkey_extractor is to execute the common key extractor.

After this, the executable with open. You can drag and drop your OTP.bin and the path will be put. No worries, even with quotes, it will still work. After, you can copy and paste the Common Key and press Ctrl+C to quit.

Manually

Download the hex editor of your choice. Open your OTP.bin with it.

At byte 0E0 or 0xE0, select the first 32 bytes. Spaces do not count. WARNING: You hex editor might select 2 bytes per 2 bytes.

Just a reminder, one letter = one byte.

Copy and paste it and paste it in a notepad window for instance.

And there you go!