Yes we can dance around what an exact definition of Linux is... the system Torvalds invented did not have the functionality of which you speak. If you say that root can be removed from the security policy and your average person reading this gose out and gets any of the major flavors of Linux, will they be able to do that? Of course not... Linux being open source can be completely modified... so what then is the functional definition of Linux? I used the one I'd heard most frequently (the kernel as provided by kernel.org), you disagree with this, and I recognized your points as valid exceptions... I still contented that systems like SE Linux are the exception to Linux and not the rule, and therefore constitute individual systems and not Linux as a whole.
How about you tell me what, in your expert opinion defines the Linux operating systems and we can continue the conversation from there?
As I replied to chsh, I am going with accepted definitions... the NCSC and NIST both say Windows NT is a microkernel. This was a paper on the abstracts of operating system security, not on arguing semantics of specific systems, variants of these systems, or anything else of that nature.
I believe its VERY contestable that it remains a microkernel.
I am sorry here Maestr0, but this is incorrect. Trusted Solaris, Trusted IRIX, and HP-VV are completely different operating systems than their untrusted counterparts. They are merely work alikes (that is they can be used for the same tasks, not that they function exactly the same). These systems have modified the architecture to allow for a reference monitor concept, they have their discretionary access policies extended, mandatory access controls added, in fact one of the aspects that is unchanged from their untrusted counterparts is the assurances. Systems like Trusted Solaris are rated at B1, which means no additional assurances over their untrusted counterparts.
Ok, thats just silly. A secure or "trusted" UNIX system (including all the ones above) just means they are on the NSA's EPL (Evaluated Product List) and have been given a indexed rating of the "assurance" level you can expect. This does not make them any less UNIX based or UNIX like. If you are so sure they are not UNIX maybe you can explain to me why all the afore mentioned companies have been paying for their UNIX IP for the last 20 years.
The aforementioned companies still pay for UN*X rights with regard to their standard operating systems (Solaris, IRIX, HP-UX) and for specific technologies in these other systems.
The trusted operating system arena has been an interesting one, frequent attempts to make a security kernel, and then run UN*X on top of that have left many people confused about what exactly the definitions of everything is... again I opted to use what I felt to be the most common and widely accepted definitions as I was in no way wishing to enter a debate based on terminology.
I didn't say it was based on XENIX, I said Secure XENIX, which is a totally different animal, again that is a functional replacement, but very different on the inside. In fact nearly NT's entire security policy (excluding mandatory access controls) is lifted directly from Secure Xenix.
Ugh. VMS was created by Digital and is not UNIX - true. One of the engineers Dave Cutler (also RSX-11) was later hired by MS to design NT - right. However. NT is not based on Xenix (aka UNIX) it was orignally intented to be an extension of the OS/2 api, hence why it was originally named OS/2 3, but after the release of Windows 3.0 they decided to hell with that and to extend the Windows api instead.
No, it isn't productive, nor is it the path I wanted this to take. It was supposed to be an abtract about quantifying operating system security... not comparing and complaining about specific definitions of operating systems. I attempted to use the most widely accepted definitions and I hope the fact that I have clairified this will put an end to such debated points here... otherwise the original subject will be left behind over irrelevant semantics.
I understand your point here but for the sake of discussion, is it productive? Lets say they are linux based or linux like.
Again, these matters would need to be resolved by those talking about the systems in which they are comparing, I merely wished to provide the format in simpler terms, which is used to measure OS security. (The norton system, would be a specific system and not the OS as a whole, and NTSP6 vs SP4 offer the same models, and capabilities, the only difference would be assurances.
I mean is my Windows NT with SP6 still Windows NT? How about SP4? What about the kernel hooks Norton Anti-Virus puts in, still Windows?
You are the one that brought up the EPL's, not me. ;) Besides, redhat and I think suse have already been evaluated against ISO-15408.
Just keep in mind that all your EPL stuff and government auditing and such, takes time and a shitload of money. Who is going to pay for all this for Linux?
Yes it can, but this article wasn't about specific operating systems or their non-production level, extensions. The operating systems I mentioned were simply to clarify a point with something people might be more famialir with and to make some elements a little less abstract by showing their context.
SELinux can be used to introduce Mandatory Access Controls as well as some other security models in Linux and is a good application of some of the subject matter you covered in your tutorial.