#123093 - Stylpe - Sun Mar 25, 2007 2:23 am
So, I had this crazy idea the other day: An application that can transfer files to other flash carts!
Some of the functionality I imagined:
-Download Play functionality to share the app itself (would need several versions of the app file on your cart patched with different DLDI patches)
-Direct remote text file viewing
-A share mode and a leech mode, where in share mode the app announces its presence to DSes nearby in leech mode, and those then browse and request files, and the app will queue up the requests and send them as fast as it can in order of request
-In share mode: an auto and manual mode, where manual mode lets you allow or deny every request, while auto mode allows all requests. Maybe also a Read-Only mode.
The seed for the idea was that I wanted to play CV:PoR with a friend the other day, but I'd forgotten to put the rom on my cart =( and of course, Download play wouldn't work. And I thought, what if I could just copy it from him?
So I thought I'd ask two questions here first:
Has anyone already made something like this?
And if not, would anyone like to help me make it? I know a fair bit of C and C++ coding, and have gotten a few test apps running on the DS, but I don't know much about DS specific development yet. Particularly the Download Play feature, don't even know if that's possible (hence the "crazy" part of crazy idea :P). I know there is at least one FTP app for the DS, so excepting Download Play it ought to be possible.
I'm thankful I found this forum though, seems like there are a lot of nice people here if I need help or have questions =) I have a few other crazy ideas I might post about later, one which I call the Portable Orchestra...
#123096 - tepples - Sun Mar 25, 2007 2:56 am
| Stylpe wrote: |
| The seed for the idea was that I wanted to play CV:PoR with a friend the other day, but I'd forgotten to put the rom on my cart |
Say what?
| Quote: |
| I don't know much about DS specific development yet. Particularly the Download Play feature, don't even know if that's possible (hence the "crazy" part of crazy idea :P). |
First go to Wikipedia to look up "digital signature".
_________________
-- Where is he?
-- Who?
-- You know, the human.
-- I think he moved to Tilwick.
#123097 - Lynx - Sun Mar 25, 2007 3:00 am
And when your done reading that, how about you read the rules?
_________________
NDS Homebrew Roms & Reviews
#123101 - felix123 - Sun Mar 25, 2007 3:35 am
Two problems no one managed to solve yet:
1. Download play
2. Adhoc mode
Maybe you are the one.
_________________
Nintendo DS homebrew on Wikipedia
#123103 - dantheman - Sun Mar 25, 2007 4:07 am
Theoretically, if you are near a Wifi access point, couldn't you start DSFTP on the host DS and use the wget command in DSLinux on the receiving one? I've never used wget, but apparently it allows FTP downloads within DSLinux.
#123105 - Stylpe - Sun Mar 25, 2007 4:19 am
Er, the rom I mentioned is a backup of course. That is, I didn't back it up myself, but I DO own it. It's just more practical to bring one cart instead of ten, plus I get to have homebrew, books and music.
The WP article on digital signatures has a lot of info, what were you trying to tell me, tepples?
And what rule in particular did you refer to, Lynx? I did read the post in this section, and it didn't say no talking about roms. So I figured I didn't have to be that specific and careful about it. I'll remember it for later though, if that's what you were referring to.
felix123: I suppose this stops the idea dead in its tracks =P I thought Adhoc mode had been figured out. Think I could get it to work by requiring a wireless access point? I'll have to look up some info on how the DS's network capabilities
#123109 - dantheman - Sun Mar 25, 2007 4:33 am
Yeah, we don't really talk about "backups" at GBAdev.
Tepples was trying to tell you that even if ad-hoc was correctly figured out, the DS would reject the download, since everything that goes through Download Play must be RSA signed, and since we don't have the key to sign it, the download won't be accepted. You can get around this by having a flashed DS on the receiving end though, as that removes the RSA signature check. There has been one demo of an application that transfers files via Download Play, but it's limited and requires a flashed receiving DS. Check a few pages back in the DS dev section for a thread about a WMB client for the DS, and work your way backwards from the last page to find the most recent download. It doesn't transfer the files to a homebrew device, only to the RAM of the receiving DS, after which point the program is launched.
#123182 - HyperHacker - Sun Mar 25, 2007 11:54 pm
| Stylpe wrote: |
| Download Play functionality to share the app itself (would need several versions of the app file on your cart patched with different DLDI patches) |
Or just the patches themselves, to be applied on the fly.
_________________
I'm a PSP hacker now, but I still <3 DS.
#123214 - thegamefreak0134 - Mon Mar 26, 2007 7:56 am
[offtopic] Couldn't one simply "borrow" the signature of another game, and use that? (Say a DS download station demo or something.) Or does the signature check the entire program being sent? (In which case, how long until someone figures out this key?) [/offtopic]
I will be honest here. I own MarioKartDS, the game, I purchaced at walmart. I will send you a picture of it to prove it. As it is not possible to patch a real cart to my knowledge, and I wanted to be able to play the offline tracks online, I downloaded (OMG!) the same exact version I had already bought, applied the patch, and went on my happy way. I see no problem with this, although I totally abolish the idea of downloading such images that one does not own, or even the idea of being able to transfer one ROM to another cart. As such, I do mean to inform you that such practices should not be discussed further here. We realize that there are legitimate uses for such things, but all too often more illegal purposes are in mind, and the last thing we need is a lawsuit because our tool allowed it.
However, (that having been said) I do like the idea of a file-sharing program. Also, I remember hearing that a member of the community was working on an ad-hoc mode for the DS, although I don't quite remember who that was. My memory is not as good as it used to be. Oh, and my memory is not as good as it used to be.
You know, if one could set the DS itself up as an access point... o.O It's bound to be possible, linux can turn regular wireless cards into access-point mode with the right software I believe.
I'm through ranting now, someone else rant for a while.
-thegamefreak0134
_________________
What if the hokey-pokey really is what it's all about?
[url=http:/www.darknovagames.com/index.php?action=recruit&clanid=1]Support Zeta on DarkNova![/url]
#123219 - HyperHacker - Mon Mar 26, 2007 8:51 am
Action Replay DS and Nitro Hax provide a means of patching official cards in a sense. There are codes to play the offline tracks online.
You can't "borrow" a digital signature, and the odds of someone cracking the key are slim to none. Basically a signature is a hash of the file, encrypted with a public/private key system like RSA. The trick is you do it backward - swap the public and private keys. Thus, anyone can decrypt the signature to verify that the encrypted hash is correct, but only Nintendo can encrypt the hash. This is the reverse of regular public/private key encryption, where anyone can encrypt but only one can decrypt. In either case, the problem is the same: you need the key to defeat it, and brute-forcing a 2048-bit RSA key is going to take many times the age of the universe.
You can exploit holes, such as modifying any area that's not covered by the signature; this is how WifiMe works. However, there's really only enough space in a Download Play binary that isn't signed to put in a simple WifiMe bootstrap, and the exploit was fixed anyway.
I do wonder if appending data to the end of the binary affects it; if not, you could use the WifiMe exploit and point it to some appended data. However, it still wouldn't work on firmware V4+.
_________________
I'm a PSP hacker now, but I still <3 DS.
#123259 - josath - Mon Mar 26, 2007 5:19 pm
| thegamefreak0134 wrote: |
| As it is not possible to patch a real cart to my knowledge, and I wanted to be able to play the offline tracks online, I downloaded (OMG!) the same exact version I had already bought, |
The first mario kart hack that came out required the original cart & a passme (no backups). I know this, because I used it. It wasn't until later that someone came up with a patch for the rom.