Re: Hypothetical design question

[Fernando Schapachnik <fernando () mecon gov ar>]

En un mensaje anterior, Nick Lothian escribió:
> > The problem with "restricting malicious things" is that the 
> > same action can
> > be veiwed as desirable or malicious, depending on intent.  
> > Intent is an
> > intangible.  Computing systems tend to deal poorly with intangibles.
> >
> > If I type 'rm -fr /', my intention is to prepare a machine 
> > for a new OS
> > load, prior to a reformat.  If an intruder types 'rm -fr /', 
> > his intentions
> > are *likely* (can't say for sure without directly asking the 
> > intruder!) to
> > be somewhat more malicious.
> >
> > The OS has no way of determining who the "real" user is and 
> > which intention
> > is desirable and which isn't.  If you try to enumerate a list of
> > "potentially malicious code" that shouldn't be run from 
> > Application X you'll
> > be at it for the rest of your life; a never-ending, 
> > never-winning battle.
> > :-(

People interested in such approaches might want to take a look at tool developed
by Niels Provos: SysTrace. In short, you make a "recording" run of the tool to
capture what system calls it performs. Then the tool is forbidden to make any
other. It even takes account of parameters:
http://www.citi.umich.edu/u/provos/systrace/


Regards.

Fernando.