LCA 2009: Making Linux more secure

Sam Varghese
Friday, 16 January 2009 04:22

Opinion and Analysis

Russell Coker is not a man who sleeps with his computers. But he does come pretty close - two servers are positioned in a little cabinet in his bedroom, one being his server and the other his Security Enhanced Linux "play machine."
The play machine is open to anyone to log in and try to break the security. The root password is out in public - this is one of the many ways in which he engages with the wider FOSS community and a way by which he tried to improve what has become the project to which he devotes a considerable amount of time.

Security Enhanced Linux is a project begun by America's National Security Agency; it comprises a kernel patch to add security features, and patches to applications to allow them to determine the security domain in which to run processes.

To use Russell's own words, "For example, /bin/login selects the domain for user processes according to configuration files and the security policy database."

His interest in SE Linux was piqued after he attended the 2001 Linux symposium in Ottawa and listened to a talk by the NSA's Peter Loscocco. As a Debian developer, he felt it should be part of the distribution and thought it would take him a few months to do the integration.

It took much longer and it has certainly kept him interested. He has ended up making a sterling contribution to the SE Linux project - on the upstream front he has expanded and improved the example policy configuration, enhanced the run_init and spasswd utilities, developed a devfsd module for managing devfs file contexts, implemented improvements to the setfiles program, and extended strace to trace SELinux system calls. (Due to the evolution of SE Linux and Linux in general some parts of his work - such as the devfsd module and spasswd - are now obsolete.)

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