RE: lsm truly "generic" allowing complete choice? Clean? Simple? I don't think so.

From: LA Walsh (
Date: Wed Feb 12 2003 - 02:13:55 EST

> -----Original Message-----
> From: Russell Coker
> I think that most people who want to use LSM and similar
> systems don't want to
> re-write any significant portion of their applications.

	I would agree -- that is true for _most_ people.
> People who want 
> serious security and are prepared to re-write applications 
> will probably want 
> a high-assurance kernel and won't use Linux.
	Why rewrite?  My security policy is burned into a ROM as 
well as all my files -- and all files are set to 777, how many 
applications am I going to need to port to fit on an embedded 

Why shouldn't I be able to config the kernel at compile time to include the basest of functionality, I put in a terminal program, maybe, a copy of a video and audio player, device drivers for a dvd/cdrom, an ethernet interface and maybe a custom remote/LCD display. Where do I need or want UIDs' or want checks for 'execute' access? If I call 'exec', its because it's burned into the ROM that way and I don't care about 'execute' bits.

Maybe I'd be able to configure out paging support as well...Think of linux in your toaster with a cute penguin on the side... You load your pre-sliced bread into the bread dispenser, and then right after you finish the morning coffee (started brewing when you turned off the alarm for the last time, or maybe earlier) and finish the slashdot morning news, you click the toast icon on your kitchen desktop and the bread dispenser drops the bread into the toaster.

Now how many of those home-appliance IP's will need security controls? Hopefully about as many people need security on their appliances now -- you have a locked door parameter and an isolated internal net...if you need security for your appliances -- someone has already broken into your house. That's not good. You don't design every appliance, range, fridge and stereo with DAC security controls -- they are assumed safe behind your front door.

Now what cheap OS can we put on those appliances? What's 'free' these days and is adaptable as a chameleon (I hope). Certainly no dinosaur OS's, that's for sure.

> For all the machines I run (hand-held, laptop, embedded > server, desktop, and > server) I plan to keep Unix permissions whether I need them > or not. Removing > them breaks too much compatability at the moment. Maybe if > someone else gets > a few thousand Linux machines running without any Unix > permissions and fixes > a lot of the bugs I'll consider it. --- It's not *for* you...a no-security machine wouldn't be useful as a general purpose machine. You'd have something akin to has readonly/system/hidden...something less than DOS 1.0 since it even had those.

The idea was 'completely generic' to support implementation of any of the security policies/models -- including those that require audit. Audit isn't just for 'audit' can be very useful in IDS and to a small extent, verification.

The points needed for audit, possibly with some augmentation might also allow for performance statistics on the level Win2k/NT has. I have to believe that the combined talent of linux programmers has to exceed that of MS. Creativity and control are opposite forces -- the more of one you have, the less of the other. But MS has some software that does quite well in benchmarks -- at least giving linux a run-for the money. I think one of the reasons why is instrumenting and performance figures that are tied into every kernel. You know when the disk is your bottle neck, or your memory, you know how many programs are spilling. You don't have to setup a special kernel or write extra software. It's all built-in. Of course in the linux world, it'd be a build-time config, but if done right, I'd leave it on all the time (I'd expect < 1% performance impact in typical cases).


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This archive was generated by hypermail 2b29 : Sat Feb 15 2003 - 22:00:38 EST