Savegames keys

Hello,

Fisrt, sorry for my poor english. It's not my native language.
I have some questions regarding the savegames keys.

I played with segher's tool.
And, I successfully unpacked some savegame files with the following keys:
- sd-key (shared)
- sd-iv (also shared)
- md5-blanker

But, to pack a savegame file, I needed my wii's keys:
- NG-id
- NG-key-id
- NG-mac
- NG-sig
- NG-priv

I wonder how these keys allow to protect data.
I understood that these keys are used to sign the savegame file.
But, I can load in my wii savegames from other wiis. There's even website dedicated to savegames fils sharing.

So, could it be possible to generate these keys ? Put fake mac address, id or key ids ?

What is the goal of using these special keys ?
Why shared keys are not enough ?

Regards,
ShovAge

You can use the segher's tools rip off compiled for windows by me... (FE100 & it's keygrabber)
one is a packer and unpacker for savefiles... the other just grabs the stuff from your savefile and keydump (only ecc key)...
it gets the shared keys used in unpacking from hackmii.com

[wiicrazy.tepetaklak.com]

You can just use the keygrabber and use the segher's tools too...

You don't need to put any fake data into those private stuff (NG files), all you need is already in your wii...

And about the protection...

Mainly, savefiles are encrypted & decrypted using a shared secret (sd-key)
but they get signed by each wii's own private ecc key to prevent tampering of the data... hence savefiles also contains the public ecc key/certificates of the signer wii so they can get verified and loaded by other wiis... other wiis know the shared secret so what they do is decrypt the data and check the signature and if signature matches allow the savegame to be copied...

The most important key in packing savefiles is of course ecc key, it's the private key of your wii used in signing process of the savefile...

Any one of savefile contains all those information in the NG files except the ecc key... you can get your wii's ecc key using bushing's xyzzy application...



Edited 1 time(s). Last edit at 01/10/2009 12:14AM by WiiCrazy.

I know it.
I already used your tool and repack save games.

But you do not answer to my questions ;)
Is my english so poor ?

Quote
ShovAge
I know it.
I already used your tool and repack save games.

But you do not answer to my questions ;)
Is my english so poor ?

Not your english, but in your post it's not evident that you actually accomplished that task...

Actually given the answer in the second phase (edited my post) before even reading this :)

Hi,

Thank you a lot WiiCrazy.
Finally, The answer is obvious,
these NG keys are used to sign the savegame, so it prevent tampering of the data.

I assume that it is possible to generate fake keys.
However, it's more simple to grab these keys with bushing's tool.

Thank you for your answer and your tool.
Thanks to segher too.

PS: I tried to copy a guitar hero savegame from my wii to my sd card. And, it fails.
Do you know if it's a known issue ? If you have no idea, I will investigate on my side.

There is a protection for wiiware & online games & vc games in the system menu... you should use gecko os rebooter function to patch the system menu to remove the protection temporarily... Go to rebooter options, select nocopy patch and press b on wiimote to reboot the system... then you can copy the save..