PIN for Login

Windows 10 added a new “PIN” login method, which is an optional login method instead of an Internet based password through Microsoft or a Domain password through Active Directory. Here is a web page explaining some of the technology (don’t watch the YouTube video) [1]. There are three issues here, whether a PIN is any […]


The Wayland protocol [1] is designed to be more secure than X, when X was designed there wasn’t much thought given to the possibility of programs with different access levels displaying on the same desktop. The Xephyr nested X server [2] is good for running an entire session from a remote untrusted host on a […]

Some Ideas for Debian Security Improvements

Debian security is pretty good, but there’s always scope for improvement. Here are some ideas that I think could be used to improve things.

A security “wizard”, basically a set of scripts with support for plugins that will investigate your system and look for things that can be improved. It could give suggestions on LSMs […]

Servers and Lockdown

OS security features and server class systems are things that surely belong together. If a program is important enough to buy expensive servers to run it then it’s important enough that you want to have all the OS security features enabled. For such an important program you will also want to have all possible monitoring […]

More EVM

This is another post about EVM/IMA which has it’s main purpose providing useful web search results for problems. However if reading it on a planet feed inspires someone to play with EVM/IMA then that’s good too, it’s interesting technology.

When using EVM/IMA in the Linux kernel if dmesg has errors like “op=appraise_data cause=missing-HMAC” the “missing-HMAC” […]

IMA/EVM Certificates

I’ve been experimenting with IMA/EVM. Here is the Sourceforge page for the upstream project [1]. The aim of that project is to check hashes and maybe public key signatures on files before performing read/exec type operations on them. It can be used as the next logical step from booting a signed kernel with TPM. I […]


I’ve just setup the Yama LSM module on some of my Linux systems. Yama controls ptrace which is the debugging and tracing API for Unix systems. The aim is to prevent a compromised process from using ptrace to compromise other processes and cause more damage. In most cases a process which can ptrace another process […]

Deleted Mapped Files

On a Linux system if you upgrade a shared object that is in use any programs that have it mapped will list it as “(deleted)” in the /proc/PID/maps file for the process in question. When you have a system tracking the stable branch of a distribution it’s expected that most times a shared object is […]

Passwords Used by Daemons

There’s a lot of advice about how to create and manage user passwords, and some of it is even good. But there doesn’t seem to be much advice about passwords for daemons, scripts, and other system processes.

I’m writing this post with some rough ideas about the topic, please let me know if you have […]

BTRFS and SE Linux

I’ve had problems with systems running SE Linux on BTRFS losing the XATTRs used for storing the SE Linux file labels after a power outage.

Here is the link to the patch that fixes this [1]. Thanks to Hans van Kranenburg and Holger Hoffstätte for the information about this patch which was already included in […]