PGD shenanigans

[doctorgoat]

I'm working on something for Elminage Gothic for PSP.

It uses script files for almost everything, and the scripts between the PC US version and PSP JP version are in the same format.

However, I'm only able to decode PGD files. I can't re-encrypt them.

This would be slightly helpful, but the disc already includes all the unencrypted PGD files.

So what I need to do is modify the decrypted files and re-insert them, but it's not possible to just replace the PGD files with unencrypted copies or modify them in their encrypted state. There also isn't a data install feature.

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[noname120]

Which tool did you use in order to decrypt it?

PPSSPP contains valuable information about this encryption: https://github.com/hrydgard/ppsspp/blob ... k/amctrl.c
You can use the function int sceDrmBBCipherInit(CIPHER_KEY *ckey, int type, int mode, u8 *header_key, u8 *version_key, u32 seed); with the parameter mode = 1 in order to encrypt it.


Another way is to patch the executable of the game so that it loads the unencrypted content.

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[Hykem]

Take a look at this: https://github.com/Hykem/sign_np/blob/master/pgd.c
You can write a small application using those routines. It's being used in "sign_np" for PGD decryption and encryption.

[doctorgoat]

PPSSPP decrypts, but JPCSP decrypts and dumps the key and dumps both the pre and post encryption files.

The PGDs are also in both encrypted and decrypted forms on the disc for some weird reason. I wasn't sure the decrypted ones were identical until I checked that. I have no diea why they're leaving those on.

edit:
at least, I THINK it's the key.

an example of one: ms0:/tmp/PGDfile.raw 11fa997106f6de3a4eb291bf0d31b1c9

[doctorgoat]

Okay, I'm almost entirely sure this isn't even feasible.

So, what's a good way that I can get a game to load a decrypted PGD file? NPloader hasn't worked, and npdecrypter doesn't recognize the PGD files being loaded at all.

[Hykem]

You can re-encrypt PGD files with the code I've linked to. You need to write your own program for that, since there's no standalone tool for PGD encryption/decryption. Just get the key with JPCSP and send it to "encrypt_pgd".

[doctorgoat]

It turns out I didn't need to! I have my hands on a way to get stuff to work now.

I just need to figure out how to properly import some files now. The file format I have to work with now is called mps2, and injecting things is a bit odd.

http://i.imgur.com/ndCjVy9.png

here's items.csv injected