Christian Haschek's blog

a blog about security projects teaching programming and other stuff

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Let's Encrypt wildcard certificates - the easy way

Oct 1st, 2023

Using DNS standalone - No credentials needed and working with every DNS provider

SSH based comment system

Jul 28th, 2023

because input fields are too easy

ZFS over iSCSI storage in Proxmox

Jul 4th, 2023

all the power of ZFS without needing large disks in your nodes

Simple Raspberry Pi powered SMS Gateway

Dec 6th, 2021

make your projects send SMS with a simple REST API

How I heat my home by mining crypto currencies

Feb 23rd, 2021

and cutting my electricity bill in half in the process

The perfect file server

Oct 31st, 2020

Use all your disks for storage by booting a USB RAM disk

Stopping phishing campaigns with bash

Aug 13th, 2020

how to poison phishing sites with fake data

The encrypted homelab

Jun 17th, 2020

creating the most secure homelab there is

The A1 Telekom Austria Hack

Jun 8th, 2020

they came in through the web shells

Threat vector: Legacy static websites

Aug 1st, 2019

Surely old HTTP-only sites can't be vulnerable if not updated for 5 years, right?

App controlled garden irrigation system for less than 20 Bucks

Jun 16th, 2019

put those Raspberry Pis you have laying around to a good use

I scanned the whole country of Austria and this is what I've found

Feb 8th, 2019

IP cameras, printers, industrial controls to name a few..

The curious case of the Raspberry Pi in the network closet

Jan 16th, 2019

how we found, analyzed (with the help of Reddit) and in the end caught the culprit of a malicious device in our network

Build your own datacenter with PXE and Alpine

Jan 13th, 2019

Who needs docker when you can run old laptops as blade servers

Teaching in minecraft

Jan 10th, 2019

logic gates have never looked so good

Making a smart meter out of a dumb one for 4 $

Oct 19th, 2018

and displaying it on an awesome dashboard

So you have been scammed

Aug 31st, 2018

a small guide on how to strike back and be a bad scamee

How to fight child pornography with a Raspberry Pi and deep learning

Jun 17th, 2018

Finding illegal content with just 10 Watts of power

Reverse engineering your mobile banking app

Apr 5th, 2018

to make a PHP script that automates checking your balances

Raspberry Pi + Deep Learning home security system

Mar 27th, 2018

From start to finish

Raspberry Pi controlled cactus lamp

Jan 3rd, 2018

adding power to a cheap lamp

Teaching your fish tank LEDs new tricks

Sep 9th, 2017

for just a few bucks and you can even make some virtual clouds

API Heaven ICO

Aug 16th, 2017

finally an ICO for an existing product

Making an awesome dashboard for your crypto currencies in 3 steps

Aug 3rd, 2017

using InfluxDB, Grafana and PHP

How to defend your website with ZIP bombs

Jul 5th, 2017

the good old methods still work today

Creating the safest ETH paper wallet with a Raspberry Pi

Jun 22nd, 2017

with a printer and without an internet connection

Accepting Ethereum payments without external services

Jun 9th, 2017

You don't need to pay for merchant systems

DIY vertical hydroponic system

Apr 23rd, 2017

grow vegetables in small spaces

Making a simple Raspberry Pi Bitcoin/Ethereum trading bot

Apr 17th, 2017

with rocket.chat and Slack status reporting

Is Guetzli useful in production?

Mar 24th, 2017

It's much better than google promised - 51% smaller images

Finding bombs in the forest

Oct 25th, 2016

treasure hunters make it easy to find them

How a scammer stole 500$ from me and in the end begged me not to tell his parents

Sep 8th, 2016

Thank god not all scammers are professionals

Forget Pay2Win - the time has come for Learn2Win

Jun 4th, 2016

how to reward players in any game for academic achievements

My door sends me chat messages

Apr 24th, 2016

Raspberry Pi powered door sensor and Rocket.Chat bot with some neat info

DIY cloud lamp for fun and profit

Feb 17th, 2016

ok, just for fun.. no profit involved

Letting students mod school computers

Jan 22nd, 2016

with some amazing results

How to visualize RADIUS connections

Jan 15th, 2016

by parsing Windows Server log files

Raspberry Pi controlled power sockets

Dec 27th, 2015

it's as easy as it sounds

My company just turned 10 and it was quite a ride

Nov 14th, 2015

also: about the time Thomas Schranz and I almost invented Dropbox

That (not so) awesome time the police raided my home

Nov 8th, 2015

lesson learned: Don't click on links random people send you

Water cooled NAS made from spare parts

Sep 21st, 2015

with Macguyverish solutions for common problems

DIY: Cheap wall mounted, water cooled PC for 51$

Sep 10th, 2015

with LED backlight and and all the good stuff

Let's analyze over twenty thousand proxies

Jul 4th, 2015

It won't get much better

Analyzing 443 free proxies - Only 21% are not shady

Jun 21st, 2015

what about the other 79%?

What would happen if you'd embed a remote JPEG with a HTTP link but the remote server is forcing HTTPS?

Jun 20th, 2015

Neue Reifeprüfung analyzed

Jun 4th, 2015

The simple way to get a good grade

Repairing a closed loop CPU water cooler with aquarium tubing

Mar 29th, 2015

air bubbles... those f***ing air bubbles

Raspberry Pi 2 wireless temperature box

Mar 16th, 2015

The π² + wifi + 1wire sensor = pure awesomeness

Chromebooks for Work & Classrooms

Jan 2nd, 2015

are they worth it?

Announcing: Socialcube LITE

Dec 28th, 2014

My proof-of-concept evolved to a intuitive platform which is free for every educational institution

Why hackits are the first thing I teach new classes

Dec 9th, 2014

they represent everything I love about computer science

My XP-based grading system

Dec 6th, 2014

a modern approach to grading in the year 2014

Raspberry Pi controlled LEDs

Aug 22nd, 2014

to visualize the up-state of my servers

IKEA Server Rack

Jul 24th, 2014

nope, not a lack rack

DIY hydroponic pot for ~36€

May 6th, 2014

Easy to build and awesome for your plants

Temperature visualization

Feb 11th, 2014

from 6 months of data

Raspberry Pi temperature monitor

Jul 28th, 2013

with a nice graph and live updates

Why are free proxies free?

May 29th, 2013

because it's an easy way to infect thousands of users and collect their data

My door sends me emails

Feb 26th, 2013

Simple and cheap Raspberry Pi burglar alarm

HTML5 heat spreading simulation

Apr 8th, 2012

with a simple JS algorithm

hackthissite.org ascii code picture challenge

Jan 9th, 2012

PHP script that filters moods from twitter

Jan 8th, 2012

..how depressed is the web?