Messages in this thread | | | Date | Tue, 3 Apr 2007 16:03:07 +0000 | From | Pavel Machek <> | Subject | Re: [PATCH resend][CRYPTO]: RSA algorithm patch |
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Hi!
> >>The best environment to deploy such functionality is > >>in updating by remote, > >>executable code (programs, libs and modules) on > >>embedded devices running > >>Linux, that have some form of kernel physical > >>security, so one can't > > > >How would that physical security look like? Would it > >include DMA > >protection? > > > >For example to do any useful form of graphics you need > >user controllable DMA, which can normally touch > >everything. > >There are various other similar "backdoors" for root. > > > >I'm somewhat sceptical because all kernels will need > >access > >to the direct mapping to operate and there are also > >various > >interfaces that can be as root (ab)used to change it. > > > >And when you can do that they can change function > >pointers > >and jump to arbitary code or change the kernel page > >tables > >and map arbitary code. > > > >Disallowing all this would probably end up with a quite > >useless kernel. > > > > > >>There are already some systems that implement and > >>utilize such functionality that > >>use windows platforms, and other Linux distros that > >>use userland > > > >Yes, at least the Vista variant was just broken. And > >its designers spent > >a lot of effort on it, but it didn't help. > > > Please read the thread i gave you for some details for > things you ask > > Have in thought that we mostly talk here about embedded > devices > that run Linux in a very restricted environment where > only specific > applications are allowed to exist and run, there are no > user logons > and these applications need to be updated by remote once > in a while > over public networks. These applications need not be > tampered with
What kind of applications are we talking about here? I'd like to hack hardware I own.
Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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