Re: [9fans] a few Q's regarding cpu/auth server

[John Floren <slawmaster@gmail.com>]

On Wed, Aug 5, 2009 at 11:15 PM, Corey<corey@bitworthy.net> wrote:
> On Wednesday 05 August 2009 19:42:54 Anthony Sorace wrote:
>> > * I hope I don't get beat up on this one (well, I hope I don't get too
>> > beat up on _any_ of these questions...), but it seems strange that
>> > something as important as a cpu/auth server would just go and boot up
>> > right into the hostowner... apparently this a non issue - so what am I
>> > not understanding?
>>
>> philosophy. plan9, like research unix before it, recognizes that if
>> you have physical access to the box, all bets are off anyway.
>>
>
> Well, sounds like a flawed philosophy taken too far.
>
> Flawed, because all bets are not necessarily off with physical access;
> and taken too far, because... dang, what harm is there in providing
> that last means of interference to a hostile?
>
> Cpu/Fs/Auth server says: "If you can touch me, I'm _all_ yours..."
>
> What a fascinatingly... loose... form of security, if you catch my drift.
>
>
>> security consists of locking your door.
>>
>
> ... which means bootes is just a quick hacksaw or boltcutter or
> crowbar away... so why even bother with a locked door?
>
> Security is ultimately about the price/time/effort/skills a potential
> attacker (or vandal) is willing (and able) to put forth in order to overcome
> a system's security measures. A password is amazingly effective for a
> vast number of the most common circumstances encountered in many
> typical environments.
>

I argued this once too, but eventually came around to the Plan 9 way
of thinking. Once you have physical access to the machine, it's yours
anyway. Just boot the Plan 9 CD and mount the fossil or any of the
other possibilities that arise when you are able to physically insert
bootable media into a system and force it to reboot.

If your Linux system is sitting out, oh no, there's a big scary login
prompt! First thing I try is rebooting and adding "single" to the end
of the kernel options. If that doesn't work, I grab a bootable Linux
CD, boot it, and mount your filesystem. Unless you're encrypting the
disk (probability: low), it's all mine now.

I don't remember the procedure, but I'm pretty sure VMS (reputedly one
of the most secure OSes, if not the most secure OS, in use today) has
a similar option for bypassing the console password on boot, and of
course you can always steal the disk and take it elsewhere, mount a
new boot tape, etc.


John
--
"Object-oriented design is the roman numerals of computing" -- Rob Pike