How NSA access was built into Windows

Les Mikesell lesmikesell at gmail.com
Sun Jan 21 05:20:30 UTC 2007


David Boles wrote:
>>> Protection? Do you mean does SElinux actually stop unauthorized disk
>>> and file access? Sure it does. At time too well. It stops things that
>>> some people want.
>>>
>>>   
>>>       
>> I mean cases where the standard unix mechanisms failed first, then
>> selinux did
>> something useful.
>>     
>
>
> Now I am confused. What is "standard unix mechanisms"? Please clarify that
> statement for me.
Traditional unix security is very simple.  Every process has a user and 
group id, typically
inherited from its parent process and all access to files and devices 
depends on the
modes set in the inodes and tests applied during the open()  of the 
file/device based
on the relationships of the uid/gid and modes.  It is all very easy to 
understand.

> Nothing 'standard unix mechanisms' that I can think of does
> what SElinux does. Or is supposed to do.
Yes, that is my point.  I'm looking for real cases where someone has 
subverted
a program to gain access to some uid that he should not normally be able to
use, but was prevented from doing damage by the additional selinux
restrictions.   Windows NT  made a lot of claims about being more secure
than unix too and the theories sounded good, but it didn't pan out in 
practice.
I just want to see where this has worked in practice.   I'm not 
convinced yet
that making security concepts less understandable is the way to  make things
more secure or that adding a lot of new and complex code is the way to 
reduce
security flaws. What have you seen that convinces you otherwise?

>  Have you actually looked and found
> out what it is that SElinus does? Or, again, it is supposed to do?
>
>   
My impression is that it imposes additional restrictions based on 
processes.   However
modern distributions assign unique uids to most system processes and 
traditional
file ownership and modes to restrict a subverted process from being able 
to do
much damage to anything except the ones that selinux would also have to
permit for that program's normal operation.

-- 
   Les Mikesell
     lesmikesell at gmail.com




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