Demos from pspdemocenter are not working and I identified a place of failure

[branco]

Mabe this is old newz for the active devs , but as I want to explore the emulator I downloaded all the eu/us demos from the pspdemocenter website . And I tried to load all of them and none works at all . From the logger message I identified a place to put a breakpoint in code where to start debugging one of the demos and the failure seems to be at PSP.java line 146 : byte[] inBuf = f.array(); The error is java.lang.UnsupportedOperationException on the ByteBuffer f when .array() is being called . I the dev that created that part of the code can please explain if it is a problem of stuff not being implemented to support the demos or it is about not having knowledge of the encryption used (f should be an object that supports .array() if it would be possible to make the decryption mabe ?) . Also here is the logger output :

0 [GUI] INFO emu - Jpcsp v0.6
191 [GUI] DEBUG hle - Loading HLE firmware up to version 150
217 [GUI] INFO emu - PBP meta data :
BOOTABLE = 1
CATEGORY = MG
DISC_ID = NPEH90001
DISC_VERSION = 1.00
PARENTAL_LEVEL = 5
PSP_SYSTEM_VER = 3.52
REGION = 32768
SHARING_ID = 0
TITLE = Warhammer 40,000: Squad Command
probably homebrew? false
218 [GUI] DEBUG hle - Loading HLE firmware up to version 352
234 [GUI] WARN emu - Encrypted file detected! (~PSP)
235 [GUI] INFO emu - Calling crypto engine for PRX.


Thanks for reading . Also nice job for a 3 year old project you have here .

[branco]

I did some more debugging on this thing and it looks to me at this point that mabe the code is broken in a simple way ? On maingui.java line 137:

ByteBuffer readbuffer = roChannel.map(FileChannel.MapMode.READ_ONLY, 0, (int) roChannel.size());

which obviously creates a readonly buffer . Later on at PSP.java line 146 reference from my first post the same ByteBuffer object now referenced by f tries to use a the method that requires read-write access : .array() . I also checked that with a watch on f.isReadOnly() that returned true :

byte[] inBuf = f.array();

So my problem seems to not related to having a 'bad rom' but on poor implementation .

Also I find the lack of response to my post disturbing . I do not intend to hack on the codebase using complete downloaded roms and there are 37 demos that I have to test stuff so I don't have to download any released game roms of psp games . If anyone is concered with that I may fork the code and create a github or mercurial repository if I ever decide to hack seriously on jpcsp so you will not stop anything .

ps Last paragraph is not meant as a threat but to mabe get an answer . If noone wants to have anything to do with me you can certainly give me an answer that you don't care about anything I may have found out in the limited time I spent debugging .

[BlackDaemon]

Actually these demos - packed ISO inside signed loader (maybe i wrong?), since now possible to sign homebrew - this theme should be actual.

[branco]

Actually these demos - packed ISO inside signed loader (maybe i wrong?), since now possible to sign homebrew - this theme should be actual.

http://www.pspdemocenter.com/ -> downloads -> demos ?!?!?!?!?!?!?!?!?!?!?!?!?!?!? Are these not demos and instead full games that someone would actually charge me money for or hunt me down for downloading ? They don't even let psp hacking stuff go up on their forum .

As I said if noone wants to respond to what I say about the source code I may pack my toys and go somewhere else , but I do belive my point above is actually valid and of interest for the dev(s) doing the crypto/elf module loading stuff .

[BlackDaemon]

branco, i just said about it's (theoretical) structure, it's official demos. For demos Sony uses DRM signing, JPCSP not supports it at this time, but since this DRM signing was hacked...who knows?

[branco]

Weather someone wants to subvert me or not I should definetly get some sleep . I seem to be edgy at the moment . And when I'm edgy funny stuff happens that is not in my favor . I mean at least you answered which is a progress

[Hykem]

@branco: What BlackDaemon means is that those demos are signed by Sony.

Code:

235 [GUI] INFO emu - Calling crypto engine for PRX.

That line means our CryptoEngine found an encrypted game and attempted to decrypted it. But since it's not only encrypted but also DRM signed, the decryption will always return junk, and that's why you end up getting a buffer error.
Currently, I'm still actively investigating the DRM algorithms in order to implement this feature. For instance, PGD encryption also works with the same system and I've already fully reversed it, published in the appropriate thread and implemented in JPCSP.