softdenchi protection Topic is solved

[myloch]

Hi guys, I'm new here (but a veteran in the gaming/abandonware world). Leeching and lurking here for quite some time, I'm amazed by your site, I decided to join.

I need your help.

I found some interesting (rare) japanese games but they are plagued by this silly drm (time trial and then they die).
For example, I have an installer for the game Exit (by Taito, pc version released only in japan).
This game is no longer available and supported, any idea how to circumvent this drm? I'd like to play it.

Apparently this is a common drm in the far east, I saw cracked exes for other games in some manga/anime forums. The game creates a temp main.bin file while running trial mode in the game directory: filesize is similar to the exe, unwrapped exe maybe? Renaming it to exe and running it does nothing though.

Anyone with free time and skills wanna take the challenge?
Feel free to PM me if you have time and knowledge, for any info or file.

[Scaryfun]

aboard! Maybe basetta can pass on that game to Aclair to see if it can be cracked.

[myloch]

A list of the more interesting games:

Tactical Chess (a chess game similar to Microsoft's Chess Titans)
My aquarium/Tropical fish in touch (aquarium simulations)
Let's go! In Kominato Tetsumichi/Let's cheer the Choshi electric railway!/Let's play in the model railway!
Truly Golf (a kawaii-style golf game) (http://www.4gamer.net/patch/demo/meccha ... golf.shtml) <-- demo
Crazystone - game of go
The Master of Billiards 3D (billiard with manga style characters)
Bass Fishing Championship tournament
Exit (http://en.wikipedia.org/wiki/Exit_(video_game))

Example for tests:

Code: Select all

https://www.sendspace.com/file/ybhnvk

[Golem_x86]

Hello everyone. Since this appears to be the only English page discussing SoftDenchi Wrapper (and fairly recently too), I'll give you guys some of the information I have.

I have reverse engineered the portion of the wrapper that matters, and have made an unwrapper that should be able to unwrap versions 1 through 7. But before I present that, here's what I think about SoftDenchi. Quite frankly, the wrapper system is very weak. I don't know if Paltiosoft is underestimating people, or if they're incompetent, but the wrapper presents little challenge to anyone wishing to unwrap, especially if they've already gotten a valid activation key. The wrapper's protection is encrypting a portion of the protected EXE's code, but the amount is so small it's almost meaningless. In the v7 sample I have 32 bytes are encrypted starting at the entry point. If you know about reverse engineering, you will know that the entry point typically contains the runtime initializer, and this code is similar between many executables using that runtime. So it's possible to just find another EXE with similar code, copy it over, fix a few offsets, and you're done. Exit, from above, is v6, and only had 16 bytes encrypted. There is no anti-dump, so you can just run the game, dump process, and copy over the unprotected bytes. Not only that, but the wrapper uses a publicly available PRNG implementation, and using that to perform XOR encryption. (It's a good thing they did that, because it meant less work for me. I wonder what the period on the PRNG is.) The wrapper has no support for in-memory patching of EXEs with TLS nor relocations. And you can practically skip all of its licensing checks by jumping past those instructions (and it'll decrypt and launch the game, with enough time for you to do a memory dump). Overall, it's just braindead and rather pathetic. You don't even need a code to decrypt it. If this is what company that made "the #1 DRM system used in Japan" can come up with, I think it is rather insulting to the Japanese.

OK, enough technical details. I know you want the unwrapper. So find it here:
Unwrapper + source code: http://www72.zippyshare.com/v/3lDaTxF5/file.html
Update June 2, 2015: Changed output file name encoding to default.

To use, just drag and drop the protected EXE on to the unwrapper EXE, and it'll do its work. You may see a (EXE name)_unwrapped.exe file which will be the unwrapped version, or nothing, if they don't use an embedded EXE. Check the unwrapper's output for details.

If you encounter any EXE that doesn't unwrap properly, send them my way and I'll take a look for you.

[basetta]

Very nice writeup! You're good at this.

[myloch]

New japanese drm found in some recent uploads: the name is Buddy drm. Didn't know about it, maybe it's as strong as SoftDenchi

[douggle]

Hey Golem any chance you can reupload that wrapper please?

[Golem_x86]

Reuploaded.

[oldman]

myloch , i thought you've been here for ages.
Maybe it's because i've seen your name for a long time at other places .
edit:
I just saw the date at the top ,Doh!.

[Emofruit]

Tried using the latest version of golems tool with a game protected by softdenchi released this week. It seems like it doesn't work despite the binary having the code sdw7 in it. If possible I would like some help from golem in modifying code since his post seems to suggest v7 is crackable.

[myloch]

Please someone can share the latest build (june 2, 2015) released by Golem_x86 back in the day?

I totally missed that.

[Scaryfun]

Someone asked me a couple weeks back and luckily I had downloaded it -

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[Negative]

thx for reuploaded

[tempacc987654]

thanks!

[hunnydop]

thanks