grandmaster
Veteran
The initial attack he chose was based on reading the security docs, as he wrote here.
How would this help on writeable memory like stack, doesnt really help if module X` code is untouched if its never called. Once you got a foot in the system its definitely possible to compromise it, got nothing to do with being stupid its rather almost impossible to write invincible systems.Is that something you know or you presume? It would be incredibly stupid on Sony's side not to do run time verification of the code. The xbox360 does memory hashes to prevent code injection/replacement. I assume the PS3 has a similar system.
Invincible systems, no. But robust product lines, yes. It should be possible to design systems where a crack to an individual system does not lead to a wholesale crack that allows any device to be readily compromised. Ultimately if there are per-chip keys that need to be cracked, preferably using a proprietary encryption so you can't just throw processing power at it, it'll take that however long to crack each individual console.How would this help on writeable memory like stack, doesnt really help if module X` code is untouched if its never called. Once you got a foot in the system its definitely possible to compromise it, got nothing to do with being stupid its rather almost impossible to write invincible systems.
Its not feasible to write something like the XMB or GameOS as just seperate modules. There needs to be much communication and you cant route everything through isolated SPUs (for performance reasons and development time). Actually since you can start the XMB while games are running I dont think there is ever more than one SPU isolated and most of it just runs on the PPU.Invincible systems, no. But robust product lines, yes. It should be possible to design systems where a crack to an individual system does not lead to a wholesale crack that allows any device to be readily compromised. Ultimately if there are per-chip keys that need to be cracked, preferably using a proprietary encryption so you can't just throw processing power at it, it'll take that however long to crack each individual console.
I dont see how the security of the GameOS should be a indicator of the security of Cell. The whole point is that you dont get access to the lowest level so security can be renewed instead of leaving the door open.In a way, Cell needs this attack. If it fends it off, the interest in Cell as a secure platform for big business and government should increase considerably. It's also an important test-case for future security designs. Should the defenses fail, lessons will be learnt for the next generation of 'secure' platform.
How would this help on writeable memory like stack, doesnt really help if module X` code is untouched if its never called.
Once you got a foot in the system its definitely possible to compromise it, got nothing to do with being stupid its rather almost impossible to write invincible systems.
And AFAIK the xbox360 gets hacked again and again... what does this tell you about the runtime checks?
And no, Im no Sony Insider or anything like that, I just dont believe there is alot authentification at runtime. The point of isolation is to use relatively small programms which are tested thoroughly against attacks, and which itself are pretty much restricted in what they can access. Most of the XMB wont fall into that category, but the point is that even if the GameOS is breached and cant be trusted you can still start an isolated SPU (kinda like a seperate OS itself) but its secure only aslong its function doesnt depends on the GameOS in any way (like flashing a firmware update).
Actually since you can start the XMB while games are running I dont think there is ever more than one SPU isolated and most of it just runs on the PPU.
And something like runtime checks only work on unmodifiable data which means you cant use relocation and dynamic linking aswell if you want the hashes for the code and data-sections to match.
I dont see how the security of the GameOS should be a indicator of the security of Cell. The whole point is that you dont get access to the lowest level so security can be renewed instead of leaving the door open.
sigh... Im talking about function pointers and return addresses. You can protect the code / readonly data with hashes (and that only if you dont do anything that touches it like linking/relocating). You cant protect the state of a programm with cryptographic hashes.I doubt they allow you to execute code on the stack pages. That's about the first thing I would disable and has been standard practice in modern OSs for years.
And whatever method the hacker used, he claims R/W access to system memory, doesnt matter how he got there. Now MS does their runtime checks trying to detect modifications, but AFAIK those get patched up some time after MS modifies them.As per the IBM paper the Cell's security is based on the assumption that even the HV might get compromised. The 360 was attacked on two fronts: unsigned shaders that can write anywhere in memory and custom drive firmware. The private keys have never been extracted AFAIK. Those attacks I mentioned cannot be used on the PS3 due to drive firmware encryption and memory layout differences.
Im just assuming its real, likely if the hacks going public it will be patched so theres a reason to keep it under wraps.I will believe this guy's claims when he posts the technical aspects of the hack. I too can make a picture of an open PS3 and some FPGAs and claim to have broken it.
Geohot's point seems to be that his hack is at such a low level that he can prevent measures like this actually being activated in the first place.
George Hotz said...
lv1 is in ram, i r/w ram...
January 23, 2010 8:23 PM
If they start using lv1ldr for anything I don't like...I'll just kick it out.
Just because it's isolated doesn't mean it keeps running. PPE can say no.
January 24, 2010 12:49 AM
And for GPU access, I think you already have it, just no driver. Hacking doesn't change that,
although reversing lv1 could aid development.
January 24, 2010 12:50 AM
On my system SPE3 is disabled and SPE2 runs security, leaving 6 SPEs for games and otheros.
Theres another fuse register which says which SPEs are actually broken and hard disabled in
manufacture, which mine is. But yea, I bet a percentage of PS3s could get access to all 8.
January 24, 2010 1:25 AM
The SPUs don't actually need to be hacked to do anything with the system. The PPE can kick out
isolated SPUs, so it has the higher level of control. You can just use the SPUs to load things, kick them
out, then patch to your hearts content.
January 24, 2010 2:12 AM
Granted, if we could decrypt the ISO SPUs, things would be a lot easier.
January 24, 2010 2:13 AM
Read your last paragraph in your last comment, and you'll see why I'm right.
You can't expect to know everything and dump every piece of code. This hack is enough for
homebrew, full linux, and even backups.
January 24, 2010 2:17 AM
sigh... Im talking about function pointers and return addresses. You can protect the code / readonly data with hashes (and that only if you dont do anything that touches it like linking/relocating). You cant protect the state of a programm with cryptographic hashes.
And whatever method the hacker used, he claims R/W access to system memory, doesnt matter how he got there. Now MS does their runtime checks trying to detect modifications, but AFAIK those get patched up some time after MS modifies them.
Im just assuming its real, likely if the hacks going public it will be patched so theres a reason to keep it under wraps.
I'm less opposed to piracy on the PS3 as I am on the iPhone. Obviously, it must not hurt the game manufacturers that bad, or they wouldn't continue to release PC versions of games. And if a modchip is required, that will eliminate a huge chunk of would be pirates. If you are willing to open up your system, learn some electronics, and solder, perhaps you deserve free games. I hate the tools who download blackra1n then ask me where their free apps are, and wish Apple had better DRM, which none of the top guys in the iPhone scene would touch.
Who cares about the strength of the encryption? Systems don't get hacked because the designers chose 1024-RSA instead of 2048-RSA, or 128-AES instead of 256-AES. If the system can decrypt it, you can decrypt it.
And yes, your understanding of the hypervisor is correct. If it's working properly, it shouldn't give me access to the resources I want...but thats what the hardware I add is for, to make the system not work so properly at exactly the right time.
January 21, 2010 10:14 AM
Losses due to piracy are incredibly hard to measure. For example, I have 3 Miley Cyrus songs in my iTunes library, but I really don't think she lost any money because of me...
Piracy in the iPhone scene bothers me for a different reason. The people who want cracked apps seem to be the biggest leeches around, who'd never give anything back to the scene and don't appreciate the legit uses for jailbreaks. Also theres a big difference between a $1 app and a $60 game, which is why I think the people are like this...too cheap to spend a dollar.
Thinking about piracy in television, I wouldn't be watching LOST if I couldn't pirate the first two seasons and catch up. So they gained a viewer.
The real reason I'm against piracy on this blog is the DMCA and lawyers though. It's not a moral issue.
January 21, 2010 3:22 PM
The real reason I'm against piracy on this blog is the DMCA and lawyers though. It's not a moral issue.
Obviously, it must not hurt the game manufacturers that bad, or they wouldn't continue to release PC versions of games.
If you are willing to open up your system, learn some electronics, and solder, perhaps you deserve free games
Yeah, he kind of dug a hole for himself and fell into it with that comment. I am all for paying for the games you play, and myself haven't pirated anything since some time in the late 90s (not counting the ~3500 or so arcade ROMs I torrented for use with MAME maybe 5 years ago of course. ...But I deleted all of those long ago now.)Very generous of him to offer up all of his personal wealth and belongings to whoever has the smarts to gain access to them.