Arian K. - Retrieving & decrypting all certificates, the entire console PC Miiverse method, debugging Nintendo Network accounts, discovering a ton of other things in Nintendo Network from reverse engineering + most of the hax that can be performed through console Miiverse on PC at a basic level + most of the Miiverse API functions. (the owner of this site aka me)
PF2M/PokemonFan2000Man/Lane - Motivation, getting me started with using web debuggers and therefore started with this entire thing, discovering a lot of functions in the API, coding JS payloads for all methods to make them easier, making this popular, and doing things while I was at school. ;^)
I pwned U!/IPU - Motivation yet again, a lot of motivation + the original inspiration for me to post custom images, for PF2M to create MCIT, and then for this method to come into existence, and also the original development of the SecureInfo_A exploit, which paved the way for a newer serial number changing exploit.
Disclaimer: Please stop calling this the API.
Read the Q&A page for more info.
Part 1: installing the certificate
Afterwards, go to the next step here.
The first thing to do is to obviously get the client certificate working in Chrome. If you aren't already using Google Chrome for this, use it.
First, go to my database of these certs.
Use any 3DS/Wii U certificates you'd like, but I recommend you use Wii U Olive Prod 1.
Whether you're using Mac OS X, Windows, a Linux distro, whatever, you can probably figure out how to install the p12 file on your machine.
It doesn't matter how you install it, you just need it installed. The password is "alpine".
Now, go to Nintendo's ECS endpoint to test the certificate.
If you did everything right and the certificate(s) successfully installed, you should be able to select one of them. Select either CTR Common Prod 1 or Wii U Common Prod 1, it depends on what you have installed. If you've installed any other certificates, that's fine.
If you don't see a box like this, the certificate(s) either didn't install right, or you need to restart your browser (or computer). If you don't see this box, you may have recieved either ERR_SSL_PROTOCOL_ERROR, or the error specified in the image nearly below this. If you did, just follow along, except if you recieved ERR_SSL_PROTOCOL_ERROR, and in that case, the certificate didn't install right.
Afterwards, you may see a screen like this.
If you see this, this doesn't mean anything. Your browser just hasn't accepted Nintendo's server certificate, and it's not really supposed to since Nintendo doesn't use these server certificates anywhere else.
Go ahead and hit "Advanced", and then proceeed. Don't worry, literally nothing will happen.
Afterwards, if everything was successful, you should see the ECommerceSOAP endpoint right here.
If you use any certificates other than the CTR Common/Wii U Common certificates, you will get a 401 message like this. It doesn't matter though, you won't need to access this site, you were still successful.
If you do see these, congratulations.
You will have to follow this exact same process for the other websites I'm going to mention.
Don't be stupid, you will know when you have to select the certificate and proceed.
If you don't want to do this in the future, trust the Nintendo CA - G3 certificate.
Move on to the next step here.