category: coding

AWS SES CreateReceiptRule: Unavailable Operation

29 Apr, 2021 - 1 minutes

Trying to set up an AWS SES receipt-rule and get an error InvalidAction: Unavailable Operation?

Automate the boring stuff: New feature branches

Repitition sucks. Repeating the same things manually over and over again. All of this boring, unnecessary manual work needs to be annihilated,

Today: Creating new feature branches

IoT Temperature and Humidity Sensor

25 Jan, 2019 - 7 minutes

This is a walkthrough for setting up a NodeMCU with a Si7021 temperature and humidity sensor as an IOT device.

It will collect sensor information, and continuosly report them to Grafana and MQTT.

Advent Of Code Day 1

1 Dec, 2018 - 1 minutes

Advent of Code has started again - here is a PHP solution to Day 1 - including two code-golfed variants :)

Git commit signing

16 Dec, 2017 - 1 minutes

I've been trying to set up git commit signing, and was treated with the following error:

error: gpg failed to sign the data
fatal: failed to write commit object

Optimizing Alexa lambda functions

30 Jul, 2017 - 2 minutes

A basic NodeJS Alexa fact skill based on the fact template builds to a 4.5 MB deployment package (and that is with best zip compression). This is way too much for code which does just spit out a random string.

automated gitolite backups

27 Jun, 2017 - 1 minutes

Since I run a gitolite server for my private projects, I needed a way to regularly backup these repositories. The following script is run via crontab as the gitolite user, and creates bundled versions of all hosted repositories. Those are then pushed via SMB to a network attached storage.

Shiny new domain

18 Feb, 2017 - 1 minutes
Got myself a shiny new hipster domain. Took the chance to move hosting to AWS, and ditch wordpress in favor of a static generated site by Hugo.

512-Byte Clock

24 Feb, 2013 - 1 minutes
So I coded a tiny little 512-byte program fitting into a bootsector, which displays a big clock. I even managed to squeeze switchable fore- and background colors and a key to toggle 12 vs 24 hour display in there. Now the sector is filled up to the limits, only 1 byte left. That’s 509 Bytes of Code & Data for a functioning clock program + 2 Bytes for the bootsector marker.

Breaking QuickStego

18 Jan, 2013 - 4 minutes

Target: QuickCrypto's QuickStego Version 1.2.0.1

QuickStego is a tool that can hide unencrypted text data in BMP image files.

The first look with PEiD reveals a Visual Basic executable, the crypto analyzer tells us something about CRC32. This may be used as some kind of verification of the data.

Trying the program on some small Bitmap files shows an unchanged file size, but many changed image data bytes, even for a message as short as one char (I used ‚A‘ for the test). The text is thus hidden directly in the pixel data, presumably by LSB method, with some overhead for management.

Real Small Programs Part 2: AsmSfv

29 Feb, 2012 - 2 minutes

The next „real small program“ is a SFV Verifying utility. Its without doubt the smallest one flying around in the interwebz, and also one of the fastest, if not the fastest :) (ironically my quick tests showed its faster than both QuickSfv and RapidSfv hehe)

Real Small Programs: Service Tool

17 Feb, 2012 - 1 minutes

Finally coded something in Assembler again!

A fully functional alternative to Windows Service Manager in only 11kB of uncompressed executable :)

Linux daemon with inode watch

1 Feb, 2012 - 2 minutes

A simple example of a linux daemon watching a directory or file with inode watch. Changes are logged to syslog