[HN Gopher] Hardware Security Exploit Research - Xbox 360
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       Hardware Security Exploit Research - Xbox 360
        
       Author : nazgulsenpai
       Score  : 60 points
       Date   : 2024-12-19 20:26 UTC (2 hours ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | Lammy wrote:
       | > So - here is a hopefully informative write up of my Journey to
       | figuring out how these guys were running unsigned code in 2011 on
       | a XBOX 360
       | 
       | > XBOX 360 Security defeated - 2011
       | 
       | I realize this post is more about hardware security than software
       | security, but if the benchmark is unsigned code execution then
       | the author should at least mention the 2007 (King Kong shader
       | exploit) and 2009 (SMC hack -- same root flaw but executed
       | automatically at boot) methods of achieving the same:
       | 
       | - https://github.com/Free60Project/wiki/blob/master/docs/Hacks...
       | 
       | - https://github.com/Free60Project/wiki/blob/master/docs/Hacks...
        
         | PaulHoule wrote:
         | Back in the day I really liked my 360 whereas my ONE seems like
         | a mistake.
        
       | dinartem wrote:
       | 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 wrote:
         | Congratulations, 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
        
           | SteveNuts wrote:
           | I'm curious how it fares against a modern iPhone or similar,
           | has that ever been compared?
        
           | liamwire wrote:
           | I have a hard time believing the 'since' part of that
           | description. Intuition suggests the latest iPhone would take
           | that crown each year.
        
           | jsheard wrote:
           | I 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
        
         | notavalleyman wrote:
         | What 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 wrote:
           | They 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 wrote:
           | A 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.
        
           | nemothekid wrote:
           | Limiting piracy is the ongoing reason, but there is also the
           | historical reason of the Video game crash of 1983 which led
           | to Nintendo's Seal of Quality.
           | 
           | Essentially as the platform owner, you want to ensure games
           | sold for the platform "just work", and if you have a bunch of
           | third parties running bad software, consumers would lose
           | faith in the platform altogether.
        
           | brokenmachine wrote:
           | They are rent seekers.
        
         | vlovich123 wrote:
         | I 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 wrote:
           | I 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 wrote:
         | Can you speak to some of the harder or more interesting
         | challenges you faced during that time?
        
           | dinartem wrote:
           | One 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.
        
             | fragmede wrote:
             | damn, that's bad ass. did that simulator run on a Windows
             | system or was it something more esoteric?
        
             | bananaboy wrote:
             | Amazing! Thanks for sharing! What sort of things are you
             | working on now?
        
             | kridsdale1 wrote:
             | This is the coolest HN post I've read in months.
             | 
             | Cheers.
        
       | kaoD wrote:
       | > Note - Newer revisions of XBOX 360 has no access to CLK and you
       | must use Matrix oscillator
       | 
       | If there's no CLK line on the mobo, does this mean newer X360s
       | have everything that might be clocked (I assume at least CPU, GPU
       | and V/RAM?) in a single chip, SoC-like?
        
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       (page generated 2024-12-19 23:00 UTC)