Christian Hascheks blog

You should self-host your mail server - maybe even at home - because spam is a solved problem

If you have spent a few days online in self-hosting or [data-so..

The ultimate Raspberry Pi gitops cluster - Booting and auto provisioning a Docker Swarm cluster with PXE and enjoying zero-downtime deployments from a single git repository

Ever since the first Raspberry Pi came out I wanted to create some kind of cluster with them. The fi..

Sending Emails to my 3-year-old - How I'm using email and timecapsules as a fun legacy for my son to find

In 2020 just in between two lockdowns, my wife gave birth to our son Linus . I'm not going to des..

Let's Encrypt wildcard certificates - the easy way - Using DNS standalone - No credentials needed and working with every DNS provider

Let's Encrypt is one of these services that seemed impossible just a few years ago. The first certif..

SSH based comment system - because input fields are too easy

This blog is now 11 years old and I've been thinking about a comment system for some time. I don't w..

ZFS over iSCSI storage in Proxmox - all the power of ZFS without needing large disks in your nodes

For almost a year now I have been using Proxmox as my main hypervisor in my homelab. When the electr..

Simple Raspberry Pi powered SMS Gateway - make your projects send SMS with a simple REST API

Sometimes one needs to send a few SMS. Doesn't matter if it's because you have a [homelab]( https://w ..

Build your own datacenter with PXE and Alpine - Who needs docker when you can run old laptops as blade servers

I have recently developed a slight obsession over Alpine Linux . Everyone..

How I heat my home by mining crypto currencies - and cutting my electricity bill in half in the process

After building my own smart meter using 4$ in parts I started chec..

The perfect file server - Use all your disks for storage by booting a USB RAM disk

If you've ever thought of building a file server, you probably had one or more of these thoughts ..

Stopping phishing campaigns with bash - how to poison phishing sites with fake data

A few days ago my wife got a text message that was obviously a bad phishing attempt ![It says: Our ..

The encrypted homelab - creating the most secure homelab there is

If you are a homelabber or are in charge of a bunch of physical..

The A1 Telekom Austria Hack - they came in through the web shells

On the 3rd of February 2020 I received an encrypted email on 3 of my email addresses from a person c..

App controlled garden irrigation system for less than 20 Bucks - put those Raspberry Pis you have laying around to a good use

I was looking for a method to keep the plants happy without spending too much money on irrigation sy..

Threat vector: Legacy static websites - Surely old HTTP-only sites can't be vulnerable if not updated for 5 years, right?

A few weeks ago something happened that wouldn't change how a small company in Vienna thinks about s..

I scanned the whole country of Austria and this is what I've found - IP cameras, printers, industrial controls to name a few..

Disclaimer: This article is the result of a few weeks of research. I did report the most..

The curious case of the Raspberry Pi in the network closet - how we found, analyzed (with the help of Reddit) and in the end caught the culprit of a malicious device in our network

Last week I got a message from my dad (who works with me at a client) with an image attached. ![Mes..

Teaching in minecraft - logic gates have never looked so good

edit Since I had so much success with my XP based grading system I thought I'd try to use actual gam..

Making a smart meter out of a dumb one for 4 $ - and displaying it on an awesome dashboard

As a geek who has a few servers and other devices at home I can't stop thinking about my power outpu..

So you have been scammed - a small guide on how to strike back and be a bad scamee

So you have been scammed It's okay, it happened to the best and even large companies aren't bul..

How to fight child pornography with a Raspberry Pi and deep learning - Finding illegal content with just 10 Watts of power

The thing about the internet is, if you give people an open platform, the scum will follow. Analy..

Reverse engineering your mobile banking app - to make a PHP script that automates checking your balances

Our Austrian banks (seemingly) hate developers as they don't give you an API to check banking statem..

Raspberry Pi + Deep Learning home security system - From start to finish

Raspberry Pi controlled cactus lamp - adding power to a cheap lamp

This christmas I got this LED cactus lamp that seems to be in every store now. Since it's so light a..

Teaching your fish tank LEDs new tricks - for just a few bucks and you can even make some virtual clouds

**In this project I'll upgrade a cheap fish tank LED light to be dimmable, controllable via Wifi and..

API Heaven ICO - finally an ICO for an existing product

We have been busy the last year in polishing up an internal tool to a finished product. Meet [API H..

Making an awesome dashboard for your crypto currencies in 3 steps - using InfluxDB, Grafana and PHP

If you have invested in crypto currencies in order to hodl them you might find yourself checking the..

How to defend your website with ZIP bombs - the good old methods still work today

[update] I'm on some list now that I have written an article about some kind of "bomb", ain't I? --..

Creating the safest ETH paper wallet with a Raspberry Pi - with a printer and without an internet connection

Since I got asked the question about safe storage of ETH a lot I thought I'd make a tutorial for..

Accepting Ethereum payments without external services - You don't need to pay for merchant systems

When I first thought about implementing payment via a crypto currency I looked at the available solu..

DIY vertical hydroponic system - grow vegetables in small spaces

I wanted to do this project for years but only recently decided to give it a try. Over the last few ..

Making a simple Raspberry Pi Bitcoin/Ethereum trading bot - with rocket.chat and Slack status reporting

[update] I have extended the bot to be able to trade **E..

Is Guetzli useful in production? - It's much better than google promised - 51% smaller images

[Google recently]( https://research.googleblog.com/2017/03/announcing-guetzli-new-open-source-jpeg.ht ..

My door sends me chat messages - Raspberry Pi powered door sensor and Rocket.Chat bot with some neat info

The result Github repo: [Link]( https://github.com/geek -..

Finding bombs in the forest - treasure hunters make it easy to find them

In the end of WW2, when Vienna was overtaken by allied forces, the Wehrmacht was pushed in the woods..

How a scammer stole 500$ from me and in the end begged me not to tell his parents - Thank god not all scammers are professionals

[Update] If you have been scammed then you might want to read my newer post [So you have been scamme..

Forget Pay2Win - the time has come for Learn2Win - how to reward players in any game for academic achievements

<img class="img-thumbnail" src=" https://www.pictshare.net/200/8bdc5ae944.jpg " style="float:right;" /..

Why hackits are the first thing I teach new classes - they represent everything I love about computer science

[update] I've created a website called 0xf.at which hosts all my hackits. Ev..

My door sends me emails - Simple and cheap Raspberry Pi burglar alarm

[UPDATE] I've rewritten this article for a more modern approach: [My door sends me chat messages](ht..

HTML5 heat spreading simulation - with a simple JS algorithm

I was reading an algorithm book the other day and found a rather interesting section about simulatio..

DIY cloud lamp for fun and profit - ok, just for fun.. no profit involved

NOTE: For maximum fun, activate the [Cloud to butt]( https://chrome.google.com/webstore/detail/cloud -..

DIY hydroponic pot for ~36€ - Easy to build and awesome for your plants

So this is my first non-IT post on my blog and I hope it will help somebody save a few bucks. One o..

Letting students mod school computers - with some amazing results

I posted these photos initially on reddit/imgur and got overwhelmingly good feedback so I thought I'..

How to visualize RADIUS connections - by parsing Windows Server log files

Note: This tutorial is working for Windows Server 2003 to 2012R2 with NPS installed. It's not curren..

My company just turned 10 and it was quite a ride - also: about the time Thomas Schranz and I almost invented Dropbox

Hello readers! This entry will be about my company Haschek Solutions a..

IKEA Server Rack - nope, not a lack rack

I recently moved and had the most geeky problem there is: **Where do I put my servers and the coffe..

Raspberry Pi controlled power sockets - it's as easy as it sounds

Disclaimer: I'm not an electrician and I would not use this proof-of-concept in reallife because it ..

Chromebooks for Work & Classrooms - are they worth it?

When I first heard about Chromebooks a few years ago, I thought the Idea is awesome but I didn't rea..

That (not so) awesome time the police raided my home - lesson learned: Don't click on links random people send you

A few years ago I saw the blooming of new IRC communities. In fact I haven't seen so many people in ..

Water cooled NAS made from spare parts - with Macguyverish solutions for common problems

In this project I will build a water cooled NAS made from [my 51$ water cooling solution]( https://bl ..