Posted by gloxkiqcza 4 hours ago
> news sites are overhyping the release/leak/whatever of the rom keyseeds, saying it could be used to fully unlock the ps5. i've already stated on twitter and i'll state it again. rom and seeds alone are NOT enough to pwn a ps5, you either need fuses and nandgroups to complement it
> ... or alternatively, you need to find bugs in the rom that you can use to exploit the ps5. neither of these are easy and require immense work. also, decapping a ps5 apu to retrieve the fuses optically will prove useless to the end user because those fuses are encrypted/xored/obfuscated
Probably could have been avoided if Sony kept the Linux version of the Playstation still alive. Imagine what the (console) world would have looked like, if it was still alive. I never got the chance to even try it myself before it was gone, but I'm sure a lot of the homebrew community's energy could have been redirected towards it instead, hitting two flies with one swath.
The causality here is backwards; Sony removed Other OS support precisely because the first jailbreak (a glitching attack) relied on it.
IMHO, removal of this feature should have triggered Sony having to pay back the amount of taxes cheated.
But it was fun.
> According to The Cybersec Guru, this is an unpatchable problem for Sony, because these keys cannot be changed and are burned directly in the APU.
I'm just speculating at this point, but what could prevent Sony from anticipating this exact situation and burning several keys in the APU? I mean, eFuse is not exactly a new technology. That way, once a key is leaked, Sony could push a firmware update switching the APU to a new key which hasn't been leaked yet.
If keys are recovered using some form of low level hardware attack, as was almost surely the case here, the attacker can usually recover the unused key sets too.
If the chip manufacturing provisioning supply chain is leaky the new keys will probably be disclosed anyway, and if the key custody chain is broken (ie, keys are shared with OEMs or third parties) they will definitely be disclosed anyway.
So if v1 is signed by key A, v2 is signed by key B and invalidates key A; a console that installs v2 wouldn't be able to install v1 after, but that's not a problem for Sony.
But, I'm not sure how many companies would be able to manage their keys properly to ensure that someone with access to key A doesn't have access to key B.
If these are asymmetric key pairs and the device side key was extracted from the device... Switching keys wouldn't help, and it's not a huge deal by itself --- having the device side key doesn't allow you to make a firmware image the device would accept.
So if you’ve blown 4 fuses you can’t do a patch that requires only 2 fuses to have blown, it’s a pretty wild solution.
Edit: it’s actually 22 fuses
[0]: https://www.chromium.org/developers/design-documents/tpm-usa...
> By default, the boot ROM will only consider bootloader entries with a version field that matches the version field of the first entry, and will stop iterating through the entries is a mismatch is found. The intent is to ensure that if some subset of the bootloader entries are upgraded, and hence the version field of their entries is modified, then the boot ROM will only boot the most recent version of the bootloader. This prevents an accidental rollback to an earlier version of the bootloader in the face of boot memory read errors, corruption, or tampering. Observe that this relies on upgraded bootloader entries being placed contiguously at the start of the array.
[0] https://http.download.nvidia.com/tegra-public-appnotes/tegra...
Firmware v2 requires a switch with no more than one fuse blown and blows the first fuse.
If you install v2, you can't install v1.
Nintendo can make 22 firmware releases that disallow rollback.
If your console blows a fuse before Nintendo intends to, you won't be able to install firmware until a firmware is released that will run with that number of fuses blown. And, depending on how things are implemented, you might not be able to run the firmware that you have either.
If there was a breach, I'd expect keys for the PS4 to be leaked as well which would be quite handy. There are soft jailbreaks you can do currently on the PS4, but they're not full on CFW (custom firmware) and don't persist reboots.
This also goes into a bit more detail regarding how these keys are used.
Once PS3 was cracked enough to run game mods, every PS3 GTA freeroam session was overrun with obnoxious cheaters, ruining it for everyone else. (Sorta like the tech industry.)
In most computer tech things, I'm all Linux, OpenWrt, Coreboot, GrapheneOS, etc., but the game console is one thing that that I like being locked down.
Nasty filler to add that to the page.
General question: (I don't know enough about cryptography)
Are these symmetric keys or asymmetric ones? Both allow you to decrypt, but only the former would allow you to make changes to it, whereas the latter would still require you to find an exploit in the next stage. I think?