Messages in this thread | | | Date | Wed, 19 Sep 2007 17:46:30 +0530 (IST) | From | Satyam Sharma <> | Subject | Re: NFS4 authentification / fsuid |
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On Wed, 19 Sep 2007, Kyle Moffett wrote: > > On Sep 18, 2007, at 19:44:59, Satyam Sharma wrote: > > > > The whole *point* here is to secure against physical access -- then how can ^^^^^^^^^^^^^^^ > > you assume "barring disassembling the system"? If you're not considering > > attacks such as those, then how _are_ you solving the physical access > > problem in the first place? :-) > > [snip lots of totally irrelevant stuff]
???
What is your point, really?
Let me repeat the situation:
I own a computer (maybe portable one, such as a laptop) that I want to protect from attackers with physical access to my system. You're proposing a scheme that claims to secure it (against attackers with physical access) but assumes: "barring disassembling the system".
Dude, looks like you're selling snake oil here.
> > > Under this setup, tinkering with my BIOS does virtually nothing; the only > > > avenues of attack are strictly of the "Install a hardware keylogger" > > > variety. > > > > Doesn't flashing/replacing your BIOS firmware/chip count as tinkering? Then > > I don't really need a "hardware keylogger", do I ... > > Ok, so you are saying your plan of attack on this system would be: > 1) Steal the laptop such that I don't notice it has been stolen > 2) Open it up > 3) Replace the very-vendor-specific BIOS chip with a reflashed one with > sufficient storage to do all the things the old BIOS could *AND* have enough > storage for an entire replacement kernel binary with a built-in keylogger, as > well as some storage for the logged password > 4) Return the laptop, again such that I don't notice it has been missing > 5) Wait for me to boot and type my password > 6) Somehow recover the laptop *yet* *again* to get the password back off of > it and decrypt the disk
Precisely. Do you think the above attack is "fantastical"?
Wow, you're amazingly naive ... good luck ;-)
[ See, if it's only your kid sister that you want to "protect" your 36GB worth of porn from, then you might as well use Windoze and one of those cute little "folder-locking" tool that we wrote back in 5th grade.
However, if "hapless North Korean spy in Washington" describes you more accurately, then you better be ready for all sorts of attacks -- from exploding cigars [1], to poisoned ballpoint pens [2] :-)
In short, you have no clue what you're talking about, and thankfully I'm not using any security software you had any part in designing :-) ]
> Yes it "can be done", but so can dumping the firmware for an iPod out through > the built-in piezo clicker[1]. USE SOME COMMON SENSE HERE PEOPLE!!! The only > "unbreakable" computer is one always disconnected and off under armed guard in > a bank vault, and even then it's only as secure as the bank in which it is > stored (which get broken into on occasion).
Thanks for repeatedly making *my* point :-)
_You_ are the one who claimed protecting systems from attackers with physical access to be a "fairly simple" problem ... and here you're mentioning how *difficult* it is ...
> I am assuming that if the laptop has sufficiently important data on it to > warrant the above steps then I am also clueful enough to: > (A) Not carry the laptop around unsecured areas,
You might carry it home, might you not? What if your lover/girlfriend/wife is one of them? [3]
> (B) Keep a close enough eye on it and be aware that it's gone by the time > they get to step 2, OR
Hmm, you'd need to be a mutant to keep "close enough eyes" on your stuff while you're sleeping ... or drugged (?)
> (C) Pay somebody to build me a better physical chassis for my laptop
ROTFL ... these "workarounds" above are even more hilarious than your earlier "fairly simple" claim.
> We are talking about *STANDARD* laptop systems with reasonably alert users. > If the user doesn't know how to properly protect the stuff on the laptop then > they probably don't know how to properly protect the other copy in their > heads, either.
Dude, if the data in there is really that important, then better not store it on a computer / disk at all :-)
> Besides, if some government wanted the data on your laptop > that bad they'd just pick you up in the middle of the night and torture your > password out of you.
Surprisingly, you have (somewhat of) a point (!)
> On Sep 18, 2007, at 19:48:16, Satyam Sharma wrote: > > On Fri, 7 Sep 2007, Kyle Moffett wrote: > > > So you can't draw any relationships between "Protect the end-user" with > > > "Protect the device FROM the end-user", the former can be done very > > > reliably to whatever level of risk-reduction you need and the latter can't > > > practically be done at all. > > > > Well, you're the one who called solving the physical access problem "easy" > > here ... :-) > > If your system equates end-user with attacker ^^
"If"? Was there ever any doubt?
Heh, did you even read the thread you just replied to?
We're talking of consoles / hardware sold by commercial companies to users here, where they want explicitly want to prevent the users from being able to hack it. So yes, end user == attacker.
> then you are *screwed* regardless!
Ah, finally you make my point again for me :-)
Thanks for the laughs,
Satyam
[1] } [2] } All real "attacks". History pop quiz: on whom? ;-) [3] } - 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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