Petter Reinholdtsen

Entries from June 2019.

Jami/Ring, finally functioning peer to peer communication client
19th June 2019

Some years ago, in 2016, I wrote for the first time about the Ring peer to peer messaging system. It would provide messaging without any central server coordinating the system and without requiring all users to register a phone number or own a mobile phone. Back then, I could not get it to work, and put it aside until it had seen more development. A few days ago I decided to give it another try, and am happy to report that this time I am able to not only send and receive messages, but also place audio and video calls. But only if UDP is not blocked into your network.

The Ring system changed name earlier this year to Jami. I tried doing web search for 'ring' when I discovered it for the first time, and can only applaud this change as it is impossible to find something called Ring among the noise of other uses of that word. Now you can search for 'jami' and this client and the Jami system is the first hit at least on duckduckgo.

Jami will by default encrypt messages as well as audio and video calls, and try to send them directly between the communicating parties if possible. If this proves impossible (for example if both ends are behind NAT), it will use a central SIP TURN server maintained by the Jami project. Jami can also be a normal SIP client. If the SIP server is unencrypted, the audio and video calls will also be unencrypted. This is as far as I know the only case where Jami will do anything without encryption.

Jami is available for several platforms: Linux, Windows, MacOSX, Android, iOS, and Android TV. It is included in Debian already. Jami also work for those using F-Droid without any Google connections, while Signal do not. The protocol is described in the Ring project wiki. The system uses a distributed hash table (DHT) system (similar to BitTorrent) running over UDP. On one of the networks I use, I discovered Jami failed to work. I tracked this down to the fact that incoming UDP packages going to ports 1-49999 were blocked, and the DHT would pick a random port and end up in the low range most of the time. After talking to the developers, I solved this by enabling the dhtproxy in the settings, thus using TCP to talk to a central DHT proxy instead of peering directly with others. I've been told the developers are working on allowing DHT to use TCP to avoid this problem. I also ran into a problem when trying to talk to the version of Ring included in Debian Stable (Stretch). Apparently the protocol changed between beta2 and the current version, making these clients incompatible. Hopefully the protocol will not be made incompatible in the future.

It is worth noting that while looking at Jami and its features, I came across another communication platform I have not tested yet. The Tox protocol and family of Tox clients. It might become the topic of a future blog post.

As usual, if you use Bitcoin and want to show your support of my activities, please send Bitcoin donations to my address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

Tags: debian, english, sikkerhet, surveillance.
More sales number for my Free Culture paper editions (2019-edition)
11th June 2019

The first book I published, Free Culture by Lawrence Lessig, is still selling a few copies. Not a lot, but enough to have contributed slightly over $500 to the Creative Commons Corporation so far. All the profit is sent there. Most books are still sold via Amazon (83 copies), with Ingram second (49) and Lulu (12) and Machette (7) as minor channels. Bying directly from Lulu bring the largest cut to Creative Commons. The English Edition sold 80 copies so far, the French 59 copies, and Norwegian only 8 copies. Nothing impressive, but nice to see the work we put down is still being appreciated. The ebook edition is available for free from Github.

Title / language Quantity
2016 jan-jun 2016 jul-dec 2017 jan-jun 2017 jul-dec 2018 jan-jun 2018 jul-dec 2019 jan-may
Culture Libre / French 3 6 19 11 7 6 7
Fri kultur / Norwegian 7 1 0 0 0 0 0
Free Culture / English 14 27 16 9 3 7 3
Total 24 34 35 20 10 13 10

It is fun to see the French edition being more popular than the English one.

If you would like to translate and publish the book in your native language, I would be happy to help make it happen. Please get in touch.

Tags: docbook, english, freeculture.
Official MIME type "text/vnd.sosi" for SOSI map data
4th June 2019

Just 15 days ago, I mentioned my submission to IANA to register an official MIME type for the SOSI vector map format. This morning, just an hour ago, I was notified that the MIME type "text/vnd.sosi" is registered for this format. In addition to this registration, my file(1) patch for a pattern matching rule for SOSI files has been accepted into the official source of that program (pending a new release), and I've been told by the team behind PRONOM that the SOSI format will be included in the next release of PRONOM, which they plan to release this summer around July.

I am very happy to see all of this fall into place, for use by the Noark 5 Tjenestegrensesnitt implementations.

As usual, if you use Bitcoin and want to show your support of my activities, please send Bitcoin donations to my address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

Tags: english, kart, noark5, standard.
The space rover coquine, or how I ended up on the dark side of the moon
2nd June 2019

A while back a college and friend from Debian and the Skolelinux / Debian Edu project approached me, asking if I knew someone that might be interested in helping out with a technology project he was running as a teacher at L'├ęcole franco-danoise - the Danish-French school and kindergarden. The kids were building robots, rovers. The story behind it is to build a rover for use on the dark side of the moon, and remote control it. As travel cost was a bit high for the final destination, and they wanted to test the concept first, he was looking for volunteers to host a rover for the kids to control in a foreign country. I ended up volunteering as a host, and last week the rover arrived. It took a while to arrive after it was built and shipped, because of customs confusion. Luckily we were able fix it quickly with help from my colleges at work.

This is what it looked like when the rover arrived. Note the cute eyes looking up on me from the wrapping

Once the robot arrived, we needed to track down batteries and figure out how to build custom firmware for it with the appropriate wifi settings. I asked a friend if I could get two 18650 batteries from his pile of Tesla batteries (he had them from the wrack of a crashed Tesla), so now the rover is running on Tesla batteries.

Building the rover firmware proved a bit harder, as the code did not work out of the box with the Arduino IDE package in Debian Buster. I suspect this is due to a unsolved license problem with arduino blocking Debian from upgrading to the latest version. In the end we gave up debugging why the IDE failed to find the required libraries, and ended up using the Arduino Makefile from the arduino-mk Debian package instead. Unfortunately the camera library is missing from the Arduino environment in Debian, so we disabled the camera support for the first firmware build, to get something up and running. With this reduced firmware, the robot could be controlled via the controller server, driving around and measuring distance using its internal acoustic sensor.

Next, With some help from my friend in Denmark, which checked in the camera library into the gitlab repository for me to use, we were able to build a new and more complete version of the firmware, and the robot is now up and running. This is what the "commander" web page look like after taking a measurement and a snapshot:

If you want to learn more about this project, you can check out the The Dark Side Challenge Hackaday web pages.

As usual, if you use Bitcoin and want to show your support of my activities, please send Bitcoin donations to my address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

Tags: english, robot.

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