Code signing

[SsJVasto]

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Remember GeoHotz the guy who DARED to look at how the PS3 processes its OPCode? From what I gathered, he managed to get the encryption keys for the PS3 and PSP by ingecting bytes 1 by 1, and checking what they look like "decrypted". Well, for the PSP's encryption, Sony couldn't do anything to stop it, we now have signed homebrew and signed CFW. Is there a particular reason why we couldn't just sign our Homebrew code and run it directly on the PSVita? Have the keys changed?

I'm figuring Wololo.Net is the best place to ask such questions...

[m0skit0]

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Remember GeoHotz the guy who DARED to look at how the PS3 processes its OPCode?

Lolwut?

he managed to get the encryption keys for the PS3 and PSP by ingecting bytes 1 by 1

Lolwut?

[SsJVasto]

Remember GeoHotz the guy who DARED to look at how the PS3 processes its OPCode?

Lolwut?

he managed to get the encryption keys for the PS3 and PSP by ingecting bytes 1 by 1

Lolwut?

Lol, that wasn't the point of my post... XD I was more curious about the status of encrypting your executables for PSP/PSVita... The background as to where the keys are found may be bogus, but they do exist, and I was wondering why people weren't using them...

[nisarg_kolhe]

Geohotz didn't find the keys, Mathieulh did! And I donno if the keys are changed or not, but it doesn't matter as Vita's PSP emulator doesn't runs XMB, but directly the game itself, so from where would you launch it? Correct me if I'm wrong...

[SsJVasto]

[...]Vita's PSP emulator doesn't runs XMB, but directly the game itself, so from where would you launch it?

That's what I'm trying to understand. What has changed between the PSP and PSVita, except that it's a different OS that loads the game? If I buy a PSP game, and download it to my PSVita AND my PSP, will they be different files/directories? Are then encoded differently?

I don't have any PSP games on my PSVita, and my previously purchased PSP Games (that I bought since 2006 on my PSP) don't appear on the PSVita's list. The download history only shows games I bought/downloaded on PSVita, and the PS3 doesn't show the games I buy on PSVita, as if it's 2 different systems. All I have are UMD's, which are like 101% useless on a Vita...

[m0skit0]

IIRC, homebrew signing is not valid anymore on 6.60 (which PSV emulates). This is most likely due to a change in some part of the encryption process. I don't think the AES keys proper changed because AFAIK the keys are hardcoded in hardware in PSP (Kirk chip). If they sign the games with a different key, the PSP would not be able to decrypt them.

[SsJVasto]

IIRC, homebrew signing is not valid anymore on 6.60 (which PSV emulates).

IIRC, PRO-CFW is signed and can be executed directly from OFW 6.60, so I'm thinking it's still possible...

If they sign the games with a different key, the PSP would not be able to decrypt them.

What's wandering around my head is this: what if they have 2 versions of PSP games on PSNStore, now? What if the Store detects what console it is, and sends the PSP-encrypted (with the key discovered by Mathieulh) to the PSP, and a second version (with different encryption) to the PSVita. It's a LOT of useless management and I doubt Sony works like that, but maybe they would just to piss hackers off...

[Xian Nox]

The Vita games are encrypted differently, yes, that's why you can't use your PSP games as-is on it.

[jc_gargma]

IIRC, homebrew signing is not valid anymore on 6.60 (which PSV emulates).

IIRC, PRO-CFW is signed and can be executed directly from OFW 6.60, so I'm thinking it's still possible...

No, its not. The fake-np trick was removed on PSP OFW 6.60, not homebrew signing. The PSVita OFW 6.60 has changed the encryption inside the emulator, so doing so doesn't work. Besides, you don't have an XMB in the emulator, where would you run the signed homebrew from?

If they sign the games with a different key, the PSP would not be able to decrypt them.

What's wandering around my head is this: what if they have 2 versions of PSP games on PSNStore, now? What if the Store detects what console it is, and sends the PSP-encrypted (with the key discovered by Mathieulh) to the PSP, and a second version (with different encryption) to the PSVita. It's a LOT of useless management and I doubt Sony works like that, but maybe they would just to piss hackers off...

I'm quite certain this is exactly what is going on. Were they not, my PSPgo games wouldn't work anymore, for lack of the decryption key on the games available. (I can still NPD even newly redownloaded games with from MediaGo, so, its the old key on mine.)
The other other possibility is "on-the-fly" games signing per download, and that would be even more cumbersome server-wise.

[wololo]

Besides, you don't have an XMB in the emulator, where would you run the signed homebrew from?

This.
Before people speak of super low-level encryption stuff, they should think of the most obvious problems, such as this one. You can sign for the PSP as much a you want, it's pointless as long as you don't even have a way to install/run the game (which would require to break the vita's encryption).