Authentication Notes

Recently we made a patched version of Flipnote Studio 3D (the EU version), which can be pointed to more or less any URL that we choose.

At the time of writing we simply changed https:// to http:// in an attempt to force authentication with the usual server over plaintext. This fails, however, since it seems that Nintendo's server won't respond to non-SSL requests.

As such, we decided to guess the response on a whim, which seems to have been partially successful.

Flipnote Gallery World

(aka "Nintendo DSi Library" outside of Japan)

User Auth

Initial connection to the FGW server:

A POST request is sent with the following:

Header	Notes
`Ugm-Token`	Likely to be an NNID auth token(?)
`Ugm-ID`	User's Flipnote Studio ID in HEX
`Ugm-ShopID`	Blank, perhaps because the app wasn't released on the EU/US eShop?
`Ugm-MAC`	Console MAC address in HEX
`Ugm-Region`	Region ID, values here
`Ugm-Language`	Language Code - [list of values] (#language-code-values)
`Ugm-Country`	Country Code - list of values (on 3dbrew)
`Ugm-Time`	Console time, format `YYYY/MM/DD hh:mm:ss`

The rest of the header (at least, I think it's the header, I can't really tell where it ends from the dump I'm looking at) is more or less the same as this:

Content-Type: multipart/form-data; boundary=t9Sf4yfjf1RtvDu3AA
Transfer-Encoding: chunked

96
--t9Sf4yfjf1RtvDu3AA
Content-Disposition: form-data; name="miiName"
Content-Type: application/octet-stream
Content-Transfer-Encoding: binary



422
--t9Sf4yfjf1RtvDu3AA
Content-Disposition: form-data; name="miiImage"
Content-Type: application/octet-stream
Content-Transfer-Encoding: binary

GIF89a@@á!˘,@@iH∞†¡É*\»∞°√á#JúH±¢≈ã3j‹»±£«è CäI≤§…ì(S™\…≤•Àó0c úI≥¶Õõ8sÍ‹…≥ßœü@É
J¥®—£Hì*] ¥©”ßP£JùJµ™’´X≥j;

18
--t9Sf4yfjf1RtvDu3AA--

0

There's two interesting things to note about this:

miiName has no content whatsoever, it's blank.
miiImage is a completely transparent 64x64 GIF image.

We assume that these were either patched out for the EU and US releases, or they're simply placeholders because we need to fully connect to the server first. We don't know for now.

(Guessed) Response:

Based on some RAM dump strings that were grouped together, we tried to guess the response on a whim. We seem to have got this at least partially correct since the 3DS makes another request after this:

Header	Notes
`Ugm-ChallengeBlob`	44-character lowercase HEX string
`Ugm-SessionID`	Unique ascii string generated by the server

Second request

After the 3DS received our response, it sent a GET request to the same URL:

Header	Notes
`Ugm-SessionID`	Same session ID as issued by the server
`Ugm-ID`	User's Flipnote Studio ID in HEX
`Ugm-Region`	Region ID, values here
`Ugm-Language`	Language Code - [list of values] (#language-code-values)
`Ugm-Country`	Country Code - list of values (on 3dbrew)
`Ugm-Version`	`3-UsEu` = Latest EU version