Google does not like self-signed SSL certs

The last few days my feeds were out of date. I manage them with Google’s solution called feedburner, you may have recognized it.

It seems that the developer of this project changed some stuff, anyway, they did not actualize my feeds. The last days (or weeks) I did not had the time to care about, but today I found some minutes.

When I tried to resync my feeds manually I got this nice red error (see also the picture):

There is an issue that must be addressed with your source feed for the feed "binfalse" sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

This is caused by my Apache redirect directive that redirects all visitors looking for an insecure URL at port 80 to my SSL encrypted content at port 443:

<virtualhost *:80>
...
        Redirect / /
...
</virtualhost>

So you see I’m caring about security ;)

This method works for a long time, but now feedburner tries to verify the certs and because of a lack of money I signed my certs by myself. So feedburner denies the access and doesn’t reread my own feeds to update its database. To repair this problem I’m just redirecting my real content and not the feeds, so feedburner is happy and why should I care about the secure connection of feedburner to my site..

Nevertheless it is not my preferred solution.

Inactivity? Not in the slightest...

Before anyone thinks I’m hibernating, I’ve just soo much to do, so there is no time to maintain this blog… Just don’t know what to do first.

This week I had a presentation, topic was “Modeling of Overflow Metabolism in Batch and Fed-Batch Cultures of Escherichia coli”. I also had to submit a study, with the headline “Modeling and evaluation of the dynamic behavior of a fermentation by simulation”, that among others analyzes the dependencies of the ratio of product concentration versus biomass concentration on biological parameters. Additionally this week I finished a work for a friend at the Otto-von-Guericke-Universität Magdeburg. He has to evaluate x-rays taken at a new detector and I developed a tool that does the trick.

As if that were not enough time consuming I’m still working on my project work, next week I have to present it in a research seminar (fortunately in German).

The reason I write this article, tomorrow is the so called Lange Nacht der Wissenschaften (translated by Google: Long Night of Science). Here the different departments of the university are presenting what they are doing, comprehensible for the public. In this event we have also a slot dealing with SUN Spots where I’m presenting some cool stuff I’ve programmed. Planed are a some introductions what Spots are and what they can do, and of course some demos. Among others we are playing with the light sensor and visualize a sunrise and a sunset, we demonstrate how one can regulate a fan depending on the temperature measured with a Spot (to induce a higher temperature a candle is planed, I hope everything will be well and the Spot won’t melt away!). Of course some basic demos are shown, like AirText or the BouncingDemo, and last but not least it is time to play. I have prepared a labyrinth that has to be solved by various people against each other (up to seven people at a time in the same labyrinth, just limited by the number of available Spots), and also I also developed a control system for the game Blobby Volley to navigate the Blobbies with a Spot, maybe you’ve heard about it ;) We also wanted to build a little car to drive around a little bit, but I’m not such engineer so this car isn’t finished…

If you are bored and don’t know what to do tomorrow visit this presentation!! It’s at 8.30 am in room 3.31 at the Von-Seckendorff-Platz 1.

Maybe I publish all the code when there is a little bit time to write some comments and how-to’s.

So you see, I’m very busy at the moment. If anyone has nothing to do, just notify me, I’ll give you something to work on!

Thunderbird to systray

Til version 3 of Thunderbird, or more exactly icedove, I used the add-on New Mail Icon to free the busy space in task list that the Thunderbird process uses even though I have this window very rarely in foreground. But it seems that there is no further development in this project, so this software isn’t compatible to the actual major release…

On my main desktop I thought I have to live with that, but on my notebook screen there is a lack of space, more than ever, so I had to search for an alternative tool. On my way I found a tool (no add-on) called AllTray, it’s available in the Debian/Ubuntu repository. That can dock any window to your tray, so it doesn’t depend on Thunderbird, you can also dock a terminal or your editor or even a complete (Oracle VM) VirtualBox instance.

For my Thunderbird problem it’s a half of the solution, because this tool doesn’t tell me whether there are unread mails. But after some more research I found a real add-on called FireTray that does the desired trick. So more space for other junk ;-)

Serv local printer

I have an old printer, an HP Laserjet 6P. It is very reliable and fast, so no need to buy a new one. But there is a problem (I thought), this printer has no network interface, it is connected with a parallel port to my host. Some minutes ago I racked my head how to use this printer with my notebook. Now I’m wondering how easy it is using cups!!

On the server side (the machine that is connected to the printer) you just have to modify this printer and check the field called “Share This Printer”, and in the administration tab just enable “Share printers connected to this system” and “Allow printing from the Internet”.

On your client you only have to publish your server. To do it for the complete system write the following line in your /etc/cups/client.conf , to set this server only for your local user account write it to your users $HOME/.cups/client.conf :

ServerName SERVER:PORT

You just have to specify the port if your server is not listening on the default port 631.

That’s it! Open a document and try to print! I still cannot believe that it is that easy ;)

Thanks to the cups-team

Need more bandwidth!

Today I got my new notebook, an IdeaPad. I had some concerns about the glare display, never used glare displays but it seems to be no problem and I don’t have a choice, Lenovo doesn’t sell that kind of notebooks without glare displays.

This laptop comes with Windows XP and of course I have to fix this bug ;)

But before I’ll delete the Windows installation and install a proper os the original system has to be backed up (I want to test some things before I decide whether to buy the laptop). So I installed the first release of „Ύπνος“ to my USB flash drive and booted into it. To back up the hard drive I mounted a piece of my main machine’s hard drive via sshfs to the laptop and copied the laptop’s hard drive to the other machine:

root@sidux /tmp % mkdir mount
root@sidux /tmp % sshfs user@192.168.0.55:/backup/lenovo mount/
password: 
root@sidux /tmp % dd if=/dev/sda of=/tmp/mount/neu.ddi ibs=1024k obs=8192

Ok, the notebook’s drive keeps 160 GB and I just have a 99 ct fast ethernet switch, so you can calculate the time I have to wait… That sucks, doesn’t anyone have a gigabit switch lying around? I would prefer Cisco switches ;)

Hopefully the backup will finish today, so I can play a little bit with the laptop and its luxurious 1.280x720 screen resolution on the 10’’ glare display.



Martin Scharm

stuff. just for the records.

Do you like this page?
You can actively support me!