We had an extremely interesting submission from Ted T'so,, Linux kernel developer, who also has an obvious interest in security, given his work with Kerberos [?] . He wrote in concerning the release by the NSA (Yes, that NSA) of a high security version of Linux. I've included his comments below.
tytso writes: "I recently attended a DARPA workshop which focused on high security open source operating systems. It turns out that parts of the U.S. government are really interested this topic; having an operating system with the necessary high-security features which they need, and for which source code is available, would be a really good thing for them. Among other things, for example, it would mean that they wouldn't have to live in terror about what might happen if Sun, IBM, SGI, et. al decided to pull the plug on Trusted Solaris, Trusted AIX, or Trusted IRIX. And they're serious enough that DARPA's willing to throw money at the problem.
While I was at this workshop, I met some folks from the NSA and they told me about a really neat project that they've been working on, called Security-enhanced Linux. One of the cool things about it is that it separates enforcement and policy. So selinux can easily support many different security policies, from the old (some would say outdated/silly) Multi-Level Secure/Bell-LaPadula model, to Domain-Type enforcement and Rule-Based Access Control models. So if you think that high-security features means the old silly, Secret / Top Secret / CMW bullshit, and needing to make sure that Secret windows don't get expose events from Top Secret windows, think again. A number of folks have found Domain Type Enforcement and Rule-Based Access Control systems very useful for securing Web servers and other real world systems.
The NSA folks just recently got permission to make their stuff available on the Web. It's just a proof of concept, and no doubt a lot of changes will need to made before people will accept integrating it into the kernel, but they have released a working system (both kernel and userspace patches --- RPM's aren't quite ready yet) based on Linux 2.2 and RedHat 6.1. So it's definitely worth a look, and in fact some folks with specialized needs might find it useful, even though it's a prototype.
Of course, the source code is all there, and we're encouraged to look at and audit the code. So paranoiacs who think that the NSA is trying to infiltrate trap doors into the Linux kernels needn't worry. (Besides, it's a different part of the government who's interested in spying on U.S. citizens, and it's much more efficient for them to break into your house, and insert a wiretapping device between your computer and your keyboard as part of a black bag job. :-)
The Web site is http://www.nsa.gov/selinux. I think it's really great that some folks at NSA's Information Assurance Research Office (IARO) have made this contribution to the Linux community. They're really nice folks (even if they can't talk about a lot of what they do at work :-).
P.S. Apparently it's not easy to get stuff published by the NSA, since their entire culture, not surprisingly, is based around not letting stuff out. This Web page went up a few days ago, and then some bureaucrats made the folks in the IARO take it down temporarily, much to their disappointment. At the moment it looks like they've finally crossed all of the bureaucratic t's and dotted all of the bureaucratic i's. But just in case, it might not be a bad idea if someone mirrored the entire tree just in case some flack in some other part of the agency tells them to take it down again...."