Tag Mandatory Access Control
Secure doesn't mean anything.
No, seriously. I’m not trying to be ironic because the title of my blog is “Brindle on Security”, which I should probably change to something more creative anyway.
During my tenure at Gentoo, running the Hardened Gentoo project, the most common question by far was “How do I secure my system?” Warning, this article may contain some flamebait, avoid it if you can’t resist flaming back 
.
Eventually we gave up and just pointed people to websites, perhaps this post can serve as that page. The answer was “What do you mean ‘secure’ your system?” Security isn’t, and can’t be, a goal by itself. You need to know what exactly you are trying to protect yourself against, your threat model, as it were.
Misunderstanding UNIX security
I just got a comment on my post about path based access control that was fairly startling to me. The more I thought about it, though, the more I thought maybe others shared the beliefs so I’m going to respond to it here. inode-based security has analogous problems to path-based security. Software opens paths, not inodes, so it very much matters what the permissions are for the file at /etc/shadow or /var/data/mydb, regardless of what the inode happens to be.
Secure Networking with SELinux
During the last year quite a bit of effort has gone into improving SELinux’ networking support, thanks to the great SELinux community. While this support is still evolving it will be very beneficial for people to try it out and give feedback so the final result is useful to more users and meets the security needs of a wider audience. As the network support in SELinux continues to evolve (there are already other ideas being discussed for possible inclusion) I’ll try to keep this post updated so that people who find it will have the latest information available.
Don't disable SELinux!
A while back I wrote a post on companies telling their customers to disable SELinux in order to get applications running and why this is a very bad thing. While I don’t see the situation getting better in the near term I did see a blog posting today from an SAP employee about using SELinux with SAP. This made me happy Since I don’t think his blog software uses trackbacks I’ll be contacting him to suggest some changes.
SELinux training
My employer, Tresys Technology, occasionally hosts an SELinux training class, many of which I’ve been the teacher for. The course outline and slides are available for free at http://tresys.com/selinux/selinux-course-outline.html but that isn’t what this post is about. I’ve been asked if I think many people would pay to take an online shorter version of the class if it were around $500. I wasn’t sure how to answer so I decided to ask the people that read my blog what they think.
The Future of SELinux (or how we are going to take over the world)
I’ve been talking to a few people about what SELinux might look like in a few years and the conversations have been fairly stimulating so I’m going to share some of the ideas here.
As you (hopefully) know in my day job I work on the SELinux policy server, which as far as I know, is the most forward looking SELinux project around. Granted all those forward looking goals aren’t published on the site, hopefully we can remedy that at some point.. So alot of this is going to be centered around the policy server, other parts are just on my wishlist.. without further ado lets get started…
On AppArmor
This will be the last thing I write about AppArmor because quite honestly it’s a waste of time to constantly refute people and I’d rather work to make security better for everyone 
.
That said, I taught an SELinux tutorial at LWE San Francisco last week, unfortunately my tutorial wasn’t one of the ones reviewed by the media, what a shame. During the tutorial I was asked about AppArmor, to which I said they could come up after the tutorial to talk about it, I didn’t want to disparage it in front of an audience of 50, I’m a nice guy like that.
Then I saw this article, which has a quite humorous title, which prompted me to go ahead and write up something that I can point to in the future.
SELinux Policy Module Primer
Its been a while since my last post, I apologize but I have a good reason I promise . I’ve been busy working on a series of patches to make the SELinux policy compiler and libraries much more stable and robust and to make optional blocks in the base policy work correctly. While the libraries and compiler are fresh on my mind I thought I’d go ahead and write an article on how the SELinux policy modules work.
Trusted what?
This is a response to an open letter from Darren Moffat to IBM. While this open letter has very little substance and is almost entirely opinion there are some things I’d like to address.
Security Anti-Pattern: Path based access control
For those of you who missed my other Security Anti-Pattern post, an anti-pattern is a commonly reinvented bad solution to a problem. There are many of these in security but one that seems to be occurring quite often these days is path based access control, an access control system that use file paths to refer to objects. To the uninitiated this may seem like a good idea at first, hopefully this blog entry will eradicate such beliefs. Apologies in advance for the length of this post.