pmeerw's blog

Sat, 09 Feb 2019

Email security testing, very straightforward, also checks web-server security.

My Email Communications Security Assessment (MECSA), by the European Commission; has postfix setup guide. has a friendly interface and gives suggestions.

posted at: 16:51 | path: /rant | permanent link

Wed, 06 Feb 2019

Linus cares about my DKIM setup :-)

Linus Torvalds points out on LKML that my DKIM setup is broken...

Date: Wed, 6 Feb 2019 08:27:25
From: Linus Torvalds <>
To: Peter Meerwald-Stadler <>
Cc: lkml <>
Subject: Re: [PATCH v3 1/4] staging: iio: ad7780: add gain & filter gpio support


 this email was marked as spam for me (and probably others) because of
this DKIM signature:

   DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple;; s=mail;

where the problem is that when the message goes through the mailing list machinery, the header whitespace will be


posted at: 17:20 | path: /rant | permanent link

Mon, 05 Nov 2018

Installing OpenJDK on Windows

This will probably be my only Windows and my only Java related blog post ever :(

The JDK version 11 is available from Oracle under a non-open-source license (which you probably don't want), and a GPLv2 license version,

For Window, you get a .zip file, but no installer. The following has to be done manually:

  1. Unzip to some directory, e.g. C:\jdk-11.0.1
  2. Set PATH: Control Panel, System, Advanced, Environment Variables. Add C:\jdk-11.0.1\bin to PATH variable.
  3. Set JAVA_HOME under System Variables. Create new variable JAVA_HOME, set value to C:\jdk-11.0.1 (without \bin)
  4. Open RegEdit program. Create keys HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft, HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment. Create string value CurrentVersion and set it to the version to use, see below.
    Windows Registry Editor Version 5.00
    [HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment]
    [HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment\11.0.1]
  5. *facepalm*

posted at: 14:57 | path: /rant | permanent link

Mon, 27 Aug 2018

Lexmark, good and WTF?!

Lexmark puts out security security updates for it's printers, also for my oldish ms415dn model; the latest firmware was released in June 2018 (LW70.TL2.P022) -- that's good, it fixes 10 CVEs (KRACK), updates OpenSSL, and adds SMBv3 support.

Yet the detailed release notes fail to mention that the new firmware also disables 3rd party toner cartridges (resulting in error code 32.46, unsupported cartridge). And Lexmark makes in rather difficult to diagnose the problem and downgrade the firmware, leaving you with a non-functional printer at an inopportune time (a.k.a. weekend) -- WTF?

Here's how to get the printer back:

  1. Find old firmware (not that I recommend Softpedia). Lexmark doesn't seem to offer it anymore, arrgh.
  2. The printer won't accept flashing a firmware downgrade via the web interface, WTF?
  3. Learn that there is a USB recovery mode: press 2,7,8 on power up until 'USB recovery' appears on the small screen next to the panel.
  4. Obtain Lexmark's USB flash utility. It didn't work on Windows 10 for me, at least the DOS (WTF!) tool worked in a virtualized Windows XP running on Ubuntu. Almost zero output from the tool in the shell, but the progress bar on the printer's screen goes up if it works.

All information is there, just a pain-in-the-ass to find. Lexmark, you can do better!

Lexmark, if you disable toner cartridges for whatever reason, say so in the release notes! I might even understand... but stop this foul play; communicate openly.

posted at: 12:31 | path: /rant | permanent link

Wed, 01 Apr 2015

Building OpenCV on Ubuntu 14.04

It's a mess...

cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_TBB=ON -D WITH_V4L=ON D WITH_OPENGL=ON -D WITH_OPENMP=ON -D WITH_IPP_A=ON -D PYTHON_INCLUDE_DIR=-I/usr/include/python2.7 -D PYTHON_INCLUDE_DIR2=-I/usr/include/x86_64-linux-gnu/python2.7 -D PYTHON_LIBRARY=/usr/lib/x86_64-linux-gnu/ ..

posted at: 13:37 | path: /rant | permanent link

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