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.pfs/.pk files found in Vita games?

Posted: Sat Feb 20, 2016 12:43 am
by ShrineFox
So I've dumped about 8 retail Vita games now using Mr. Gas's pfs encryption bypass method.
Normally, I've found that most pfs-encrypted content is decrypted when the game runs.

However, this particular game is an oddity. I've uploaded the dumped files from Soul Sacrifice Delta,
and the file that seems to contain most of the game's content (archive.pk) is still encrypted.
However, in the same directory, obviously related to this file, are archive.pfs and archive.pkh.
Image
I'm assuming that the .pfs file might be the key to undoing the encryption of the .pk, perhaps
in a similar fashion to how xorpads work on 3ds roms.

Personally I'm not interested in the contents of this archive file, but I know people who are.
More importantly, I was hoping if anyone was to analyze the .pfs file, we might be closer to understanding
PFS encryption.

Re: .pfs/.pk files found in Vita games?

Posted: Sat Feb 20, 2016 3:15 am
by Malachi
ShrineFox wrote:I've uploaded the dumped files from Soul Sacrifice Delta here,
I'm just as excited as the next person about all these vita game dumps and encryptions, but you can't post a link to a "dumped" game. It's against forum rules.

Not trying to rain on this thread or derail it, just giving you the courtesy before a mod steps in. I hope you can find a solution to this interesting topic.

Re: .pfs/.pk files found in Vita games?

Posted: Sat Feb 20, 2016 4:58 am
by ShrineFox
Alright, I'll remove the link for now, I guess if anyone wants the files they can PM me. I'm just not sure how anyone can study the files without first obtaining them but I understand, thanks for looking out for me

Re: .pfs/.pk files found in Vita games?

Posted: Sat Feb 20, 2016 8:17 am
by nyx
The .pfs file seems to contain the file list for the encrypted archive (which I assume is the pk file). What does the pkh look like?

The key should be in there somewhere, though it could also in the main executable. Or maybe the system allows for mounting encrypted archives separately. If either is true you're out of luck.

Re: .pfs/.pk files found in Vita games?

Posted: Sat Feb 20, 2016 5:13 pm
by ShrineFox
The pkh files look more similar to the pfs files than the pk files. Lots of 0x00 bytes that seem to be padding things somehow, but the main difference is that there's nothing legible in the .pkh. It also seems to have a header.

I'm no good at reverse engineering though so forgive me if I'm wrong.
All I know is considering it's related to a file that's pfs encrypted, seems too much of a coincidence for it not to be related to the encryption somehow.

Re: .pfs/.pk files found in Vita games?

Posted: Mon Feb 22, 2016 6:57 pm
by hoodlum47
My suggestion is to pose this question to the people in either the Xentax forums or the Zenhax forums. They specialize in reverse engineering game files, so your more likely to find a solution there.

Re: .pfs/.pk files found in Vita games?

Posted: Fri Feb 26, 2016 10:15 pm
by ShrineFox
A friend of mine has already figured it out, I'm afraid that the relation to the psvita encryption was a false alarm. It's merely compressed, and the .pfs in this case likely stands for "pack file system," assuming "pk" is "pack."

The giveaway would have been the lack of a variable header considering all the pk files start out with the same bytes.
Looks like there's no more need to look into this, sorry guys

Re: .pfs/.pk files found in Vita games?

Posted: Fri Sep 09, 2016 5:57 am
by g.a.u
anyway to repack them after extract .pk by this tool ?
http://rgbacrt.seesaa.net/article/437742154.html