As you probably know, the United States Government's National Security Agency early this year undertook a project called "Security-Enhanced Linux." There are some, whose tinfoil hats are on a little tight, who immediately assume that this means Linux with all kinds of back doors and things so that the government can spy on you. They avoid the fact that this is all entirely open source stuff, available to anybody and followed and audited by kernel developers. (In my experience, those who most fear this are those in whom the government would have the least interest. If there's a real concern, it's that bad guys could make use of SELinux -- but the government has a front door for those situations: they pull up in black sedans, grab their guns, and, armed with warrants, knock down the front door.)

In fact, what SELinux does is make it impossible for a wayward or misconfigured application to compromise the whole system. Through mandatory access controls, it provides tremendous granularity in security policy, giving applications only the bare minimum permissions needed to perform tasks. There are no SUID programs; nor is there a root user. And that's just the beginning.

It allows, indeed requires, that the system administrator establish a security policy, and at its tightest SELinux is pretty solid -- more so than that you'll find on any out-of-the-box Linux. It is the first and arguably biggest step toward Linux as a trusted system.

SELinux is to a truly secure operating system as Ext3 is to other journaling filesystems -- its design goals include compatibility with existing applications and, for the most part, existing system utilities; those that don't work are patched so that they will.

In short, it's a really good idea, put together by some of the best people in the business. Anyone can download and build it into an existing Linux system. It's designed against Red Hat, but that's little matter for what I have in mind.

Pause a moment and think. Think back a couple of months, before Security was spelled with a capital s. Was there any reason, any reason in the world, why anyone would not have wanted the most secure system possible? No, of course not (but for the few apps that, with the overly broad security policies we have available now, simply would not run on a very tight machine). There having never been a reason for a wide-open box, and now there being greater reason than ever for a box that's really locked down, seems to me that there is wisdom in distributions working toward adiption of SELinux as the standard kernel or at minimum an option at install.

Indeed, in many respects SELinux can be seen as a government grant to defeat Microsoft where it is weakest. It would be plain foolish for distributions not to avail themselves of the help.

The whole thing is open and documented, complete with suggestions of areas where additional work can be done to make the system even more secure. Given the number and variety of projects on which distributions have spent money to little effect, it seems they would jump at one that has slam-dunk merit.

I hope to see the SELinux kernel, further enhanced, in the spring round of distributions. There is good reason for it to become standard.

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