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Good times. I was the developer at Microsoft who designed the Xbox 360 hardware security, wrote all the boot loaders, and the hypervisor code. Note to self: yo
by dinartem 2y ago
Good times. I was the developer at Microsoft who designed the Xbox 360 hardware security, wrote all the boot loaders, and the hypervisor code.
Note to self: you should have added random delays before and after making the POST code visible on the external pins.
- spencerflem 2y agoCongratulations, haven't had a reason to mess with it myself, but I've heard it described online as the most secure piece of consumer hardware before or since
- liamwire 2y agoI have a hard time believing the ‘since’ part of that description. Intuition suggests the latest iPhone would take that crown each year.
- spencerflem 2y agoMisremembered, it was saying it was the most secure code Microsoft has written, not anyone From the excellent: https://icode4.coffee/?p=954 https://icode4.coffee/?p=954
- walterbell 2y ago> the latest iPhone would take that crown each year Apple continuously patches zero-day kernel exploits against the latest iOS and hardware, https://support.apple.com/en-us/100100 https://support.apple.com/en-us/100100
- anyfoo 2y agoThat is far from the only thing that would be relevant for such a metric. (For one thing, you also have to ask which kernel.)
- walterbell 2y agoiPhone and iPad devices have been breached by zero-days for years, unlike Xbox One.
- anyfoo 2y agoStill simplistic. "Breached" can mean a number of things, and the incentives here are very different.
- walterbell 2y agoBreached = remote control of device, bypass all vendor and owner security policy, and exfiltration of non-public data.
- anyfoo 2y agoAnd that was achieved?
- walterbell 2y agoMultiple times via iOS zero days. One example, https://www.theguardian.com/technology/2024/dec/20/whatsapp-pegasus-spyware-nso-group-hacking https://www.theguardian.com/technology/2024/dec/20/whatsapp-... > NSO Group Technologies, was accused in a lawsuit by Meta’s messaging app of infecting and surveilling the phones of 1,400 people over a two-week period in May 2019 via its notorious Pegasus software. The judge.. found the company had violated state and federal US hacking laws.. was used to infiltrate not only WhatsApp but also iPhones to extract pictures, emails and texts.. victims of the hack identified by Meta were senior government officials, journalists, human rights activists, political dissidents and diplomats.
- anyfoo 2y ago5 years ago, by state level actors. How many state level actors are trying to breach the Xbox? Your original statement was “there are kernel vulnerabilities being fixed, therefore iPhones are less secure than the Xbox one”. It’s just not that simple. I can’t make any assessment about which of those are more secure without a serious look, but this isn’t it.
- StrauXX 2y agoSure, but there are many more people looking at iPhone security than at Xboxes. The incentives, both monetary and otherwise, are much greater with iPhones than they ever were with consoles.
- SteveNuts 2y agoI'm curious how it fares against a modern iPhone or similar, has that ever been compared?
- saagarjha 2y agoiPhone has a fairly different threat model (and is more valuable to attack).
- jsheard 2y agoI think you might be mixing up the Xbox 360 with the Xbox One, the former was ultimately compromised in several ways, but the latter's security has held up extremely well for 11 years and counting. The Xbox One and its successor are easily the most secure consoles ever made. Obligatory: https://www.youtube.com/watch?v=U7VwtOrwceo https://www.youtube.com/watch?v=U7VwtOrwceo
- spencerflem 2y agoFound it! I misremembered, it was making a slightly different claim "The Xbox 360 hypervisor is probably the most secure piece of code Microsoft has ever written." from the excellent article Tony Hawk's Pro Strcpy https://icode4.coffee/?p=954 https://icode4.coffee/?p=954
- landr0id 2y agoThe Xbox 360 was overall a very, very secure device. While we don't know exactly how the folks who discovered the hypervisor syscall handler bug were able to get plaintext, it's theorized that it came from development kit and SDK leaks. With an SDK and dev kit someone could dump boot loaders and the HV. Otherwise on a retail console you can't do much. The hard drives are not encrypted but all content that can possibly contain code / save data is signed. Save data cannot contain code but introduces scripting engine / save parsing attack surface, but you can't modify it without first dumping keys from a retail console. To dump keys from a retail console you have to get code exec in the hypervisor. To attack the hypervisor you have be able to dump the hypervisor to audit it. To dump the hypervisor you have to be able to read its contents or dump it from flash. The flash is encrypted with a per-console key (and I don't think you can sniff the bus?) and RAM is encrypted. Realistically if it weren't for the original syscall handler bug and dev kits getting into researcher's hands, the Xbox 360 may have never been hacked.
- markus_zhang 2y agoStupid question, is the reason that people cannot simply dump the ROM as they do with say routers is that the rom is encrypted? But if they have the SDK they can decrypt it?
- notavalleyman 2y agoWhat are the reasons for why Microsoft wanted to lock down consoles to only run signed code? As a games console manufacturer, what are the business reasons for doing so? Thanks
- treyd 2y agoThey sell the consoles at a loss, so if you could port your own games to the consoles instead of buying the games that they could take a royalty from then they lose money. It doesn't have to be an effective circumvention to trigger the DMCA making it illegal.
- Lammy 2y agoA games console provided a platform where they could more effectively argue that “their” works “““needed””” to be protected so they could farm us (people who want to run their own code on hardware they purchased) for digital-jail technologies which would never otherwise have reason to exist. Then those technologies can metastasize fully-formed over to general-purpose computing in a way that's harder to argue against. They learned with Clipper and Palladium that trying to develop jail tech on PC would be vehemently opposed.
- lyu07282 2y agoThe opposition was pointless though, like everything has TPM/IME/etc. nowadays so we lost that war awhile ago. I don't see how consoles helped them win that war though.
- RGamma 2y agoWhen everything is locked down for good I'll go back to physical books. Vaporware games and media are not worth preserving anyway. And the games and media I do have free from prison can entertain me for a very long time. Another possible (even worse) future could be cloudification of everything. Enjoy your thin client. Of course software is bigger than entertainment which might represent a problem. We're increasingly societally locked into this digital shit.
- 2y ago
- vlovich123 2y agoI feel like random delays would make the glitch attack harder but it would still be possible given enough attempts. Seems like the bigger issue is that you can glitch the CPU reset line which corrupts the processing rather than having no effect or resetting the CPU.
- kaoD 2y agoI assume those are probably very hard to fix since (again, I assume, I'm just a hobbyist in the hardware space) that sort of glitch relies on propagation delays (e.g. a short burst triggering some latches but not others, or triggering the latches in some specific synchrony). Can anyone confirm if I'm on the right track with my guess?
- liamwire 2y agoCan you speak to some of the harder or more interesting challenges you faced during that time?
- dinartem 2y agoOne challenge was that while I started working on the Xbox 360 about three years before it would ship, we knew that the custom CPU would not be available until early 2005 (first chips arrived in early February). And there was only supposed to be one hardware spin before final release. So I had no real hardware to test any of the software I was writing, and no other chips (like the Apple G5 we used as alpha kits) had the custom security hardware or boot sequence like the custom chip would have. But I still needed to provide the first stage boot loader which is stored in ROM inside the CPU weeks before first manufacture. I ended up writing a simulator of the CPU (instruction level), to make progress on writing the boot code. Obviously my boot code and hypervisor would run perfectly on my simulator since I wrote both! But IBM had also had a hardware accelerated cycle-accurate simulator that I got to use. I was required to boot the entire Xbox 360 kernel in their simulator before I could release the boot ROM. What takes a few seconds on hardware to boot took over 3 hours in simulation. The POST codes would be displayed every so often to let me know that progress was still being made. The first CPU arrived on a Friday, by Saturday the electrical engineers flew to Austin to help get the chip on the motherboard and make sure FSB and other busses were all working. I arrived on Monday evening with a laptop containing the source code to the kernel, on Tuesday I compiled and flashed various versions, working through the typical bring-up issues. By Wednesday afternoon the kernel was running Quake, including sound output and controller input. Three years of preparation to make my contribution to hardware bring-up as short as possible, since I would bottleneck everyone else in the development team until the CPU booted the kernel.
- dvdbloc 2y agoWhat was the culture like working on this project and back in those days? I’ve always been fascinated by the development of consoles, especially the story of the 360. Any sources you recommend to learn more? I thought the Microsoft documentary on Xbox was the best I’ve found so far.
- jolan 2y agoThe Winchester revision is still considered unhackable afaik. It's crazy how many Xbox 360 revisions there were compared to other consoles.
- saturn8601 2y agoWas it ever explained why? This was an unanswered question I always wondered about from time to time. They must have done something to remove RGH capability?
- jolan 2y agoYes that revision is patched to specifically counter RGH. Microsoft disabled the ability to get the precise timing needed from the CPU and also added more filtering/robustness so the system will reset properly instead of getting into the inconsistent state of the old revisions.
- LPisGood 2y agoI’m surprised this was a task that only took a single developer!
- cbanek 2y agoHaving a single developer allows fewer offices with their windows completely covered with newspaper. Plus, there's one person doing everything, which can be a lot better than two with people who have different ideas of how to make the system work together.
- dhx 2y agoHave you seen Tony Chen's (development lead for Xbox One security) description of the Xbox 360 reset glitch hack at [1] and the effect this (and other console exploits of that time) had on Xbox One development? This is one of my go-to case study videos for the development effort required to architect a computer to resist attackers who have physical access. [1] https://youtu.be/U7VwtOrwceo?t=536 https://youtu.be/U7VwtOrwceo?t=536
- deleted 2y ago[deleted]
- landr0id 2y agoWait until you read Grimdoomer’s (yet to be published) write-up on his recent hypervisor exploit that works on the latest OS: https://x.com/grimdoomer/status/1847497275289063676 https://x.com/grimdoomer/status/1847497275289063676 It’s going to be a doozy
- Dracophoenix 2y agoHow did you feel about teenagers and college students exploiting holes in your work? Were you impressed, disappointed, amused, etc.? Oh and I'd just like to say thank you for your contribution to my childhood/adolescence.