Topic: Computer

Hardware, software & hacks

TLS with Let’s Encrypt

From now on I use TLS certificates by Let’s Encrypt for all my services (web, e-mail, XMPP etc.).

This is not a classic certification authority (CA) but an initiative which was originally founded by Mozilla, the EFF and the University of Michigan and is now provided by the Internet Security Research Group (ISRG). The goal of Let’s Encrypt is it to provide encryption everywhere by offering the required certificates for free. Since April 2016 Let’s Encrypt is not beta any longer but officially in operation.

To use Let’s Encrypt a client is required which renews the certificates via the “ACME” protocol on a regular basis as the certificates are only valid for three months. For this I use the shell script getssl with which you can automate the process very easy. This script will be executed with a cron job once a day to check the age of certificates and renew them. It will also tell the affected services to reload their configuration or restart the affected services if required.

Vintage Computing Festival Berlin 2016

In October 2016 I participated the Vintage Computing Festival Berlin ( for the first time – with my old Atari 1040STe which still works fine even after 20 years. This is especially impressive for the harddisc.

Atari 1040 STe on the VCFB 2016

There I showed how I developed my alternative desktop “Thing” and I explained the programs which I used for that (PureC, Interface, Everest and others).

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Vulnerabilities in the server of TeamSpeak 3

On multiple vulnerabilities in the server of TeamSpeak 3, version 3.0.13 are documented. This topic was also discussed on in the community of TeamSpeak and an updated version of the server had been released which fixed the vulnerabilities.

Unfortunately that updated caused other problems. If and when a new version will be released is not known at the moment.

As a short term workaround you should block the access to the port for “ServerQuery” (TCP 10011).

The second life of an old notebook

A while ago a wrote about living in Berlin soon. Due to the job I will only be at home at the weekends for the first months and don’t have access to my PC during the week. Technically my old netbook still works even after about seven years – but with its small display and the slow CPU it is barely more than a compromise solution while traveling. A regular notebook would make much more sense.

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Control AV receivers by Pioneer over the network

Pioneer VSX-529Pioneer offers a number of AV receivers with network connection which can be controlled using an app for Android or iOS, as for example the VSX-529, VSX-921, VSX-1021. The complete list can be found in the description of the apps for the receivers, like iControlAV2 or iControlAV5.

Raymond Julin found out that the interface used for these apps can be accessed very easily using telnet since the protocol is quite simple.

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