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Securely Killing Processes

Joey Hess wrote on Debian-devel about the problem of init scripts not doing adequate checks before using the data from a PID file under /var/run to determine which process to kill [1]. Unfortunately that still doesn’t quite solve the problem, there is still the issue of a race condition causing a process to die while […]

Can SE Linux Implement Traditional Unix Users and Groups?

I was asked by email whether SE Linux could implement traditional Unix users and groups.

The Strictly Literal Answer to that Question

The core of the SE Linux access control is the domain-type model where every process has a domain and every object that a process can access (including other processes) has a type. Domains […]

Logging in as Root

Martin Meredith wrote a blog post about logging in as root and the people who so strongly advocate against it [1]. The question is whether you should ssh directly to the root account on a remote server or whether you should ssh to a non-root account and use sudo or su to gain administrative privileges.


UBAC and SE Linux in Debian

A recent development in SE Linux policy is the concept of UBAC (User Based Access Control) which prevents SE Linux users (identitied) from accessing each other’s files.

SE Linux user identities may map 1:1 to Unix users (as was required in the early versions of SE Linux), you might have unique identities for special users […]

Google Chrome and SE Linux

[107108.433300] chrome[12262]: segfault at bbadbeef ip 0000000000fbea18 sp 00007fffcf348100 error 6 in chrome[400000+27ad000]

When I first tried running the Google Chrome web browser [1] on SE Linux it recursively displayed the error message in the above picture, it first displayed the error and then displayed another error while trying to display a web page […]

systemd – a Replacement for init etc

The systemd projecct is an interesting concept for replacing init and related code [1]. There have been a few attempts to replace the old init system, upstart is getting some market share in Linux distributions and Solaris has made some interesting changes too.

But systemd is more radical and offers more benefits. While it’s nice […]

Upgrading a SE Linux system to Debian/Testing (Squeeze)

Upgrade Requirements

Debian/Squeeze (the next release of Debian) will be released some time later this year. Many people are already upgrading test servers, and development systems and workstations that are used to develop code that will be deployed next year. Also there are some significant new features in Squeeze that compel some people to upgrade […]

The Yubikey

Some time ago Yubico were kind enough to send me an evaluation copy of their Yubikey device. I’ve finally got around to reviewing it and making deployment plans for buying some more. Above is a picture of my Yubikey on the keyboard of my Thinkpad T61 for scale. The newer keys apparently have a […]

Types of Security Tokens

The Security Token Wikipedia page doesn’t seem to clearly describe the types of token.

Categories of Security Token

It seems to me that the following categories encompass all security tokens:

Biometric tokens – which seems rather pointless to me. Having a device I control verify my biometric data doesn’t seem to provide a benefit. The […]

Designing a Secure Linux System

The Threat

Bruce Schneier’s blog post about the Mariposa Botnet has an interesting discussion in the comments about how to make a secure system [1]. Note that the threat is considered to be remote attackers, that means viruses and trojan horses – which includes infected files run from USB devices (IE you aren’t safe just […]