Andreas Happe: Everything

Low-hanging Security/Privacy for the Lazy 2016!

Keeping a good security and privacy is tough work. There’s always a trade-off between effort and achieved security. In this blog post I’ll mention small things that a ``normal’’ person should be able to perform — that still increase the overall security of that user’s data. <!– more –> Choose your Liege Bruce Schneier talks about the comeback of feudal security: you choose your liege lord and depend upon him for providing security.

February 25, 2016 in

OSCP: Check!

I have just received my OSCP exam success notification. This is a penetration-testing certification by Offensive Security with focus on hands-on-training.<!– more –> You get an eBook and a week’s worth of video lectures with guided exercises; access to a virtual lab with approximately 55 machines that you should gain full control over and will finish with an 24 hour exam in which you are supposed to root five target machines.

February 7, 2016 in life security

Network Concurrency Problem

A project I’m involved with has a traditional distributed client-server architecture: multiple servers are interconnected, clients connect to one more servers. In this use-case we’re expecting around four to seven servers with long-running connections between them and approx. a dozen clients with short-lived connections to the server. Initially I had used plain Java networking but during 2013 I’ve switched over to netty.io as a communication layer. Benefits were more agile networking code, better concurrency, etc.

November 13, 2015 in development tech

pathogen vs vundle

Pathogen was the first vim plugin management system that I’ve known of. The contender is Vundle which seems to be inspired in it’s configuration syntax (and name) by Ruby’s Bundler. So let’s compare those two. Pathogen Pathogen’s workings are quite easy to grasp: each plugin is a directory within “~/.vim/bundle/”; pathogen traverses through the plugin list and includes each one of them. Let’s see a sample directory: 1 2 3 4 5 6 7 [~/.

February 18, 2015 in tech linux vim

Capybara for automating Pen-Tests

After a successful penetration test a re-test is performed. The common approach is that the customer fixes the code and I perform the necessary steps to confirm that that initial security breach was closed. Sometimes it takes the customer a couple of tries to achieve that. Most security problems (XSS, CSRF, SQLi) can easily be automated tested, but I had problems automating server-side authentication and authorization problems. The test would have to emulate multiple parallel user sessions.

September 9, 2014 in linux security rails tech

Migrating to Middleman

My blog has a history of migrations. It started as wordpress, then was converted Octopress. After Octopress was missing update-love and jekyll started to be actively maintained again it switched over to jekyll. And now, it finally is based upon Middleman. Sorry for any inconvinient bugs or layout errors that will happen during the migration. Why have I switched to middleman? as I’m a RoR devleoper it seems better suited for me.

September 9, 2014 in linux rails tech

Review: Penetration Testing with BackBox

Full-disclosure: I was asked by PacktPublishing to provide a review of Penetration Testing with BackBox by Stefan Umit Uygur. They offered me a free copy of the ebook; otherwise I have not been compensated by any means for this review. The book aims to be an introduction to penetration-testing for experienced Unix/Linux users or administrators (seems like there are Linux users that aren’t administrators by now). After reading the book I believe that the assumed use-case is an administrator that wants to gain some insight into the tools that might be used against his server.

September 9, 2014 in security

Using a (host) reverse-proxy together with LXC application servers

The basic idea is to move application servers into LXC containers while keeping the HTTP server part (which is also responsible for hosting static files) on the host system. Normally an incoming request would be handled by an HTTP server on the host as well as by an HTTP server on the virtualized client: 1 browser -> http server(host) -> http server (guest) -> app-server (guest) I’m configuring the host HTTP server to directly communicate with the app worker, thus:

April 25, 2014 in tech linux virtualization

How to convert an KVM image into a LXC container

KVM was an improvement over Xen for me. Still for many use-cases a LXC are a more performance, light-weight alternative – which also seems to be en vougue nowadays. Through switching to LXC I’ve reduced my overall memory usage a bit – the main benefit is, that processes within an LXC container are separated processes within the host system. This should allow the host system to manage memory (think cache, buffers, swap, etc.

April 7, 2014 in tech linux virtualization

How to use virt-install to install new virtual machines within libvirt/kvm

I’ve been using KVM and virt-install to manage virtual machines on one of my servers, this post shows how to use virt-install. According to the package management system I’m having the following packages installed: 1 2 3 4 5 6 7 8 9 root@edgewalker ~ # dpkg -l | grep virt ii libvirt-bin 1.1.1-0ubuntu8.1 amd64 programs for the libvirt library ii libvirt0 1.1.1-0ubuntu8.1 amd64 library for interfacing with different virtualization systems ii munin-libvirt-plugins 0.

March 22, 2014 in tech linux virtualization