X-Git-Url: http://pere.pagekite.me/gitweb/homepage.git/blobdiff_plain/b6b6575e368fa0e8d3ac34a3a09aa1e21132be0e..6621ff349d531b5887d38da305c6d1fde095b36d:/blog/index.html diff --git a/blog/index.html b/blog/index.html index 7cee2eb902..de9f6e58b0 100644 --- a/blog/index.html +++ b/blog/index.html @@ -20,83 +20,42 @@
-
Some notes on fault tolerant storage systems
-
1st November 2017
-

If you care about how fault tolerant your storage is, you might -find these articles and papers interesting. They have formed how I -think of when designing a storage system.

- - - -

Several of these research papers are based on data collected from -hundred thousands or millions of disk, and their findings are eye -opening. The short story is simply do not implicitly trust RAID or -redundant storage systems. Details matter. And unfortunately there -are few options on Linux addressing all the identified issues. Both -ZFS and Btrfs are doing a fairly good job, but have legal and -practical issues on their own. I wonder how cluster file systems like -Ceph do in this regard. After, all the old saying, you know you have -a distributed system when the crash of a compyter you have never heard -of stops you from getting any work done. The same holds true if fault -tolerance do not work.

- -

Just remember, in the end, it do not matter how redundant, or how -fault tolerant your storage is, if you do not continuously monitor its -status to detect and replace failed disks.

+
Time for an official MIME type for patches?
+
1st November 2018
+

As part of my involvement in +the Nikita +archive API project, I've been importing a fairly large lump of +emails into a test instance of the archive to see how well this would +go. I picked a subset of my +notmuch email database, all public emails sent to me via +@lists.debian.org, giving me a set of around 216 000 emails to import. +In the process, I had a look at the various attachments included in +these emails, to figure out what to do with attachments, and noticed +that one of the most common attachment formats do not have +an +official MIME type registered with IANA/IETF. The output from +diff, ie the input for patch, is on the top 10 list of formats +included in these emails. At the moment people seem to use either +text/x-patch or text/x-diff, but neither is officially registered. It +would be better if one official MIME type were registered and used +everywhere.

+ +

To try to get one official MIME type for these files, I've brought +up the topic on +the +media-types mailing list. If you are interested in discussion +which MIME type to use as the official for patch files, or involved in +making software using a MIME type for patches, perhaps you would like +to join the discussion?

+ +

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, raid, sysadmin. + Tags: debian, english, standard.
@@ -104,46 +63,79 @@ status to detect and replace failed disks.

-
Web services for writing academic LaTeX papers as a team
-
31st October 2017
-

I was surprised today to learn that a friend in academia did not -know there are easily available web services available for writing -LaTeX documents as a team. I thought it was common knowledge, but to -make sure at least my readers are aware of it, I would like to mention -these useful services for writing LaTeX documents. Some of them even -provide a WYSIWYG editor to ease writing even further.

- -

There are two commercial services available, -ShareLaTeX and -Overleaf. They are very easy to -use. Just start a new document, select which publisher to write for -(ie which LaTeX style to use), and start writing. Note, these two -have announced their intention to join forces, so soon it will only be -one joint service. I've used both for different documents, and they -work just fine. While -ShareLaTeX is free -software, while the latter is not. According to a -announcement from Overleaf, they plan to keep the ShareLaTeX code -base maintained as free software.

- -But these two are not the only alternatives. -Fidus Writer is another free -software solution with the -source available on github. I have not used it myself. Several -others can be found on the nice -alterntiveTo -web service. - -

If you like Google Docs or Etherpad, but would like to write -documents in LaTeX, you should check out these services. You can even -host your own, if you want to. :)

- +
Measuring the speaker frequency response using the AUDMES free software GUI - nice free software
+
22nd October 2018
+

+ +

My current home stereo is a patchwork of various pieces I got on +flee markeds over the years. It is amazing what kind of equipment +show up there. I've been wondering for a while if it was possible to +measure how well this equipment is working together, and decided to +see how far I could get using free software. After trawling the web I +came across an article from DIY Audio and Video on +Speaker +Testing and Analysis describing how to test speakers, and it listing +several software options, among them +AUDio MEasurement +System (AUDMES). It is the only free software system I could find +focusing on measuring speakers and audio frequency response. In the +process I also found an interesting article from NOVO on +Understanding +Speaker Specifications and Frequency Response and an article from +ecoustics on +Understanding +Speaker Frequency Response, with a lot of information on what to +look for and how to interpret the graphs. Armed with this knowledge, +I set out to measure the state of my speakers.

+ +

The first hurdle was that AUDMES hadn't seen a commit for 10 years +and did not build with current compilers and libraries. I got in +touch with its author, who no longer was spending time on the program +but gave me write access to the subversion repository on Sourceforge. +The end result is that now the code build on Linux and is capable of +saving and loading the collected frequency response data in CSV +format. The application is quite nice and flexible, and I was able to +select the input and output audio interfaces independently. This made +it possible to use a USB mixer as the input source, while sending +output via my laptop headphone connection. I lacked the hardware and +cabling to figure out a different way to get independent cabling to +speakers and microphone.

+ +

Using this setup I could see how a large range of high frequencies +apparently were not making it out of my speakers. The picture show +the frequency response measurement of one of the speakers. Note the +frequency lines seem to be slightly misaligned, compared to the CSV +output from the program. I can not hear several of these are high +frequencies, according to measurement from +Free Hearing Test +Software, an freeware system to measure your hearing (still +looking for a free software alternative), so I do not know if they are +coming out out the speakers. I thus do not quite know how to figure +out if the missing frequencies is a problem with the microphone, the +amplifier or the speakers, but I managed to rule out the audio card in my +PC by measuring my Bose noise canceling headset using its own +microphone. This setup was able to see the high frequency tones, so +the problem with my stereo had to be in the amplifier or speakers.

+ +

Anyway, to try to role out one factor I ended up picking up a new +set of speakers at a flee marked, and these work a lot better than the +old speakers, so I guess the microphone and amplifier is OK. If you +need to measure your own speakers, check out AUDMES. If more people +get involved, perhaps the project could become good enough to +include in Debian? And if +you know of some other free software to measure speakers and amplifier +performance, please let me know. I am aware of the freeware option +REW, but I want something +that can be developed also when the vendor looses interest.

+ +

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. + Tags: english, nice free software.
@@ -151,288 +143,67 @@ host your own, if you want to. :)

-
Locating IMDB IDs of movies in the Internet Archive using Wikidata
-
25th October 2017
-

Recently, I needed to automatically check the copyright status of a -set of The Internet Movie database -(IMDB) entries, to figure out which one of the movies they refer -to can be freely distributed on the Internet. This proved to be -harder than it sounds. IMDB for sure list movies without any -copyright protection, where the copyright protection has expired or -where the movie is lisenced using a permissive license like one from -Creative Commons. These are mixed with copyright protected movies, -and there seem to be no way to separate these classes of movies using -the information in IMDB.

- -

First I tried to look up entries manually in IMDB, -Wikipedia and -The Internet Archive, to get a -feel how to do this. It is hard to know for sure using these sources, -but it should be possible to be reasonable confident a movie is "out -of copyright" with a few hours work per movie. As I needed to check -almost 20,000 entries, this approach was not sustainable. I simply -can not work around the clock for about 6 years to check this data -set.

- -

I asked the people behind The Internet Archive if they could -introduce a new metadata field in their metadata XML for IMDB ID, but -was told that they leave it completely to the uploaders to update the -metadata. Some of the metadata entries had IMDB links in the -description, but I found no way to download all metadata files in bulk -to locate those ones and put that approach aside.

- -

In the process I noticed several Wikipedia articles about movies -had links to both IMDB and The Internet Archive, and it occured to me -that I could use the Wikipedia RDF data set to locate entries with -both, to at least get a lower bound on the number of movies on The -Internet Archive with a IMDB ID. This is useful based on the -assumption that movies distributed by The Internet Archive can be -legally distributed on the Internet. With some help from the RDF -community (thank you DanC), I was able to come up with this query to -pass to the SPARQL interface on -Wikidata: - -

-SELECT ?work ?imdb ?ia ?when ?label
-WHERE
-{
-  ?work wdt:P31/wdt:P279* wd:Q11424.
-  ?work wdt:P345 ?imdb.
-  ?work wdt:P724 ?ia.
-  OPTIONAL {
-        ?work wdt:P577 ?when.
-        ?work rdfs:label ?label.
-        FILTER(LANG(?label) = "en").
-  }
-}
-

- -

If I understand the query right, for every film entry anywhere in -Wikpedia, it will return the IMDB ID and The Internet Archive ID, and -when the movie was released and its English title, if either or both -of the latter two are available. At the moment the result set contain -2338 entries. Of course, it depend on volunteers including both -correct IMDB and The Internet Archive IDs in the wikipedia articles -for the movie. It should be noted that the result will include -duplicates if the movie have entries in several languages. There are -some bogus entries, either because The Internet Archive ID contain a -typo or because the movie is not available from The Internet Archive. -I did not verify the IMDB IDs, as I am unsure how to do that -automatically.

- -

I wrote a small python script to extract the data set from Wikidata -and check if the XML metadata for the movie is available from The -Internet Archive, and after around 1.5 hour it produced a list of 2097 -free movies and their IMDB ID. In total, 171 entries in Wikidata lack -the refered Internet Archive entry. I assume the 70 "disappearing" -entries (ie 2338-2097-171) are duplicate entries.

- -

This is not too bad, given that The Internet Archive report to -contain 5331 -feature films at the moment, but it also mean more than 3000 -movies are missing on Wikipedia or are missing the pair of references -on Wikipedia.

- -

I was curious about the distribution by release year, and made a -little graph to show how the amount of free movies is spread over the -years:

- -

- -

I expect the relative distribution of the remaining 3000 movies to -be similar.

- -

If you want to help, and want to ensure Wikipedia can be used to -cross reference The Internet Archive and The Internet Movie Database, -please make sure entries like this are listed under the "External -links" heading on the Wikipedia article for the movie:

+
Web browser integration of VLC with Bittorrent support
+
21st October 2018
+

Bittorrent is as far as I know, currently the most efficient way to +distribute content on the Internet. It is used all by all sorts of +content providers, from national TV stations like +NRK, Linux distributors like +Debian and +Ubuntu, and of course the +Internet archive. + +

Almost a month ago +a new +package adding Bittorrent support to VLC became available in +Debian testing and unstable. To test it, simply install it like +this:

-* {{Internet Archive film|id=FightingLady}}
-* {{IMDb title|id=0036823|title=The Fighting Lady}}
+apt install vlc-plugin-bittorrent

-

Please verify the links on the final page, to make sure you did not -introduce a typo.

- -

Here is the complete list, if you want to correct the 171 -identified Wikipedia entries with broken links to The Internet -Archive: Q1140317, -Q458656, -Q458656, -Q470560, -Q743340, -Q822580, -Q480696, -Q128761, -Q1307059, -Q1335091, -Q1537166, -Q1438334, -Q1479751, -Q1497200, -Q1498122, -Q865973, -Q834269, -Q841781, -Q841781, -Q1548193, -Q499031, -Q1564769, -Q1585239, -Q1585569, -Q1624236, -Q4796595, -Q4853469, -Q4873046, -Q915016, -Q4660396, -Q4677708, -Q4738449, -Q4756096, -Q4766785, -Q880357, -Q882066, -Q882066, -Q204191, -Q204191, -Q1194170, -Q940014, -Q946863, -Q172837, -Q573077, -Q1219005, -Q1219599, -Q1643798, -Q1656352, -Q1659549, -Q1660007, -Q1698154, -Q1737980, -Q1877284, -Q1199354, -Q1199354, -Q1199451, -Q1211871, -Q1212179, -Q1238382, -Q4906454, -Q320219, -Q1148649, -Q645094, -Q5050350, -Q5166548, -Q2677926, -Q2698139, -Q2707305, -Q2740725, -Q2024780, -Q2117418, -Q2138984, -Q1127992, -Q1058087, -Q1070484, -Q1080080, -Q1090813, -Q1251918, -Q1254110, -Q1257070, -Q1257079, -Q1197410, -Q1198423, -Q706951, -Q723239, -Q2079261, -Q1171364, -Q617858, -Q5166611, -Q5166611, -Q324513, -Q374172, -Q7533269, -Q970386, -Q976849, -Q7458614, -Q5347416, -Q5460005, -Q5463392, -Q3038555, -Q5288458, -Q2346516, -Q5183645, -Q5185497, -Q5216127, -Q5223127, -Q5261159, -Q1300759, -Q5521241, -Q7733434, -Q7736264, -Q7737032, -Q7882671, -Q7719427, -Q7719444, -Q7722575, -Q2629763, -Q2640346, -Q2649671, -Q7703851, -Q7747041, -Q6544949, -Q6672759, -Q2445896, -Q12124891, -Q3127044, -Q2511262, -Q2517672, -Q2543165, -Q426628, -Q426628, -Q12126890, -Q13359969, -Q13359969, -Q2294295, -Q2294295, -Q2559509, -Q2559912, -Q7760469, -Q6703974, -Q4744, -Q7766962, -Q7768516, -Q7769205, -Q7769988, -Q2946945, -Q3212086, -Q3212086, -Q18218448, -Q18218448, -Q18218448, -Q6909175, -Q7405709, -Q7416149, -Q7239952, -Q7317332, -Q7783674, -Q7783704, -Q7857590, -Q3372526, -Q3372642, -Q3372816, -Q3372909, -Q7959649, -Q7977485, -Q7992684, -Q3817966, -Q3821852, -Q3420907, -Q3429733, -Q774474

+

Since the plugin was made available for the first time in Debian, +several improvements have been made to it. In version 2.2-4, now +available in both testing and unstable, a desktop file is provided to +teach browsers to start VLC when the user click on torrent files or +magnet links. The last part is thanks to me finally understanding +what the strange x-scheme-handler style MIME types in desktop files +are used for. By adding x-scheme-handler/magnet to the MimeType entry +in the desktop file, at least the browsers Firefox and Chromium will +suggest to start VLC when selecting a magnet URI on a web page. The +end result is that now, with the plugin installed in Buster and Sid, +one can visit any +Internet +Archive page with movies using a web browser and click on the +torrent link to start streaming the movie.

+ +

Note, there is still some misfeatures in the plugin. One is the +fact that it will hang and +block VLC +from exiting until the torrent streaming starts. Another is the +fact that it +will pick +and play a random file in a multi file torrent. This is not +always the video file you want. Combined with the first it can be a +bit hard to get the video streaming going. But when it work, it seem +to do a good job.

+ +

For the Debian packaging, I would love to find a good way to test +if the plugin work with VLC using autopkgtest. I tried, but do not +know enough of the inner workings of VLC to get it working. For now +the autopkgtest script is only checking if the .so file was +successfully loaded by VLC. If you have any suggestions, please +submit a patch to the Debian bug tracking system.

+ +

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, opphavsrett. + Tags: english, verkidetfri, video.
@@ -440,26 +211,80 @@ Archive: Q1140317,
-
A one-way wall on the border?
-
14th October 2017
-

I find it fascinating how many of the people being locked inside -the proposed border wall between USA and Mexico support the idea. The -proposal to keep Mexicans out reminds me of -the -propaganda twist from the East Germany government calling the wall -the “Antifascist Bulwark” after erecting the Berlin Wall, claiming -that the wall was erected to keep enemies from creeping into East -Germany, while it was obvious to the people locked inside it that it -was erected to keep the people from escaping.

- -

Do the people in USA supporting this wall really believe it is a -one way wall, only keeping people on the outside from getting in, -while not keeping people in the inside from getting out?

+
Release 0.2 of free software archive system Nikita announced
+
18th October 2018
+

This morning, the new release of the +Nikita +Noark 5 core project was +announced +on the project mailing list. The free software solution is an +implementation of the Norwegian archive standard Noark 5 used by +government offices in Norway. These were the changes in version 0.2 +since version 0.1.1 (from NEWS.md): + +

    +
  • Fix typos in REL names
    • +
  • Tidy up error message reporting
    • +
  • Fix issue where we used Integer.valueOf(), not Integer.getInteger()
    • +
  • Change some String handling to StringBuffer
    • +
  • Fix error reporting
    • +
  • Code tidy-up
    • +
  • Fix issue using static non-synchronized SimpleDateFormat to avoid + race conditions
    • +
  • Fix problem where deserialisers were treating integers as strings
    • +
  • Update methods to make them null-safe
    • +
  • Fix many issues reported by coverity
    • +
  • Improve equals(), compareTo() and hash() in domain model
    • +
  • Improvements to the domain model for metadata classes
    • +
  • Fix CORS issues when downloading document
    • +
  • Implementation of case-handling with registryEntry and document upload
    • +
  • Better support in Javascript for OPTIONS
    • +
  • Adding concept description of mail integration
    • +
  • Improve setting of default values for GET on ny-journalpost
    • +
  • Better handling of required values during deserialisation
    • +
  • Changed tilknyttetDato (M620) from date to dateTime
    • +
  • Corrected some opprettetDato (M600) (de)serialisation errors.
    • +
  • Improve parse error reporting.
    • +
  • Started on OData search and filtering.
    • +
  • Added Contributor Covenant Code of Conduct to project.
    • +
  • Moved repository and project from Github to Gitlab.
    • +
  • Restructured repository, moved code into src/ and web/.
    • +
  • Updated code to use Spring Boot version 2.
    • +
  • Added support for OAuth2 authentication.
    • +
  • Fixed several bugs discovered by Coverity.
    • +
  • Corrected handling of date/datetime fields.
    • +
  • Improved error reporting when rejecting during deserializatoin.
    • +
  • Adjusted default values provided for ny-arkivdel, ny-mappe, + ny-saksmappe, ny-journalpost and ny-dokumentbeskrivelse.
    • +
  • Several fixes for korrespondansepart*.
    • +
  • Updated web GUI: +
      +
    • Now handle both file upload and download.
      • +
    • Uses new OAuth2 authentication for login.
      • +
    • Forms now fetches default values from API using GET.
      • +
    • Added RFC 822 (email), TIFF and JPEG to list of possible file formats.
      • +
    • +
+ +

The changes and improvements are extensive. Running diffstat on +the changes between git tab 0.1.1 and 0.2 show 1098 files changed, +108666 insertions(+), 54066 deletions(-).

+ +

If free and open standardized archiving API sound interesting to +you, please contact us on IRC +(#nikita on +irc.freenode.net) or email +(nikita-noark +mailing list).

+ +

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. + Tags: english, nuug, offentlig innsyn, standard.
@@ -467,48 +292,111 @@ while not keeping people in the inside from getting out?

-
Generating 3D prints in Debian using Cura and Slic3r(-prusa)
-
9th October 2017
-

At my nearby maker space, -Sonen, I heard the story that it -was easier to generate gcode files for theyr 3D printers (Ultimake 2+) -on Windows and MacOS X than Linux, because the software involved had -to be manually compiled and set up on Linux while premade packages -worked out of the box on Windows and MacOS X. I found this annoying, -as the software involved, -Cura, is free software -and should be trivial to get up and running on Linux if someone took -the time to package it for the relevant distributions. I even found -a request for adding into -Debian from 2013, which had seem some activity over the years but -never resulted in the software showing up in Debian. So a few days -ago I offered my help to try to improve the situation.

- -

Now I am very happy to see that all the packages required by a -working Cura in Debian are uploaded into Debian and waiting in the NEW -queue for the ftpmasters to have a look. You can track the progress -on -the -status page for the 3D printer team.

- -

The uploaded packages are a bit behind upstream, and was uploaded -now to get slots in the NEW -queue while we work up updating the packages to the latest -upstream version.

- -

On a related note, two competitors for Cura, which I found harder -to use and was unable to configure correctly for Ultimaker 2+ in the -short time I spent on it, are already in Debian. If you are looking -for 3D printer "slicers" and want something already available in -Debian, check out -slic3r and -slic3r-prusa. -The latter is a fork of the former.

+
Fetching trusted timestamps using the rfc3161ng python module
+
8th October 2018
+

I have earlier covered the basics of trusted timestamping using the +'openssl ts' client. See blog post for +2014, +2016 +and +2017 +for those stories. But some times I want to integrate the timestamping +in other code, and recently I needed to integrate it into Python. +After searching a bit, I found +the +rfc3161 library which seemed like a good fit, but I soon +discovered it only worked for python version 2, and I needed something +that work with python version 3. Luckily I next came across +the rfc3161ng library, +a fork of the original rfc3161 library. Not only is it working with +python 3, it have fixed a few of the bugs in the original library, and +it has an active maintainer. I decided to wrap it up and make it +available in +Debian, and a few days ago it entered Debian unstable and testing.

+ +

Using the library is fairly straight forward. The only slightly +problematic step is to fetch the required certificates to verify the +timestamp. For some services it is straight forward, while for others +I have not yet figured out how to do it. Here is a small standalone +code example based on of the integration tests in the library code:

+ +
+#!/usr/bin/python3
+
+"""
+
+Python 3 script demonstrating how to use the rfc3161ng module to
+get trusted timestamps.
+
+The license of this code is the same as the license of the rfc3161ng
+library, ie MIT/BSD.
+
+"""
+
+import os
+import pyasn1.codec.der
+import rfc3161ng
+import subprocess
+import tempfile
+import urllib.request
+
+def store(f, data):
+    f.write(data)
+    f.flush()
+    f.seek(0)
+
+def fetch(url, f=None):
+    response = urllib.request.urlopen(url)
+    data = response.read()
+    if f:
+        store(f, data)
+    return data
+
+def main():
+    with tempfile.NamedTemporaryFile() as cert_f,\
+    	 tempfile.NamedTemporaryFile() as ca_f,\
+    	 tempfile.NamedTemporaryFile() as msg_f,\
+    	 tempfile.NamedTemporaryFile() as tsr_f:
+
+        # First fetch certificates used by service
+        certificate_data = fetch('https://freetsa.org/files/tsa.crt', cert_f)
+        ca_data_data = fetch('https://freetsa.org/files/cacert.pem', ca_f)
+
+        # Then timestamp the message
+        timestamper = \
+            rfc3161ng.RemoteTimestamper('http://freetsa.org/tsr',
+                                        certificate=certificate_data)
+        data = b"Python forever!\n"
+        tsr = timestamper(data=data, return_tsr=True)
+
+        # Finally, convert message and response to something 'openssl ts' can verify
+        store(msg_f, data)
+        store(tsr_f, pyasn1.codec.der.encoder.encode(tsr))
+        args = ["openssl", "ts", "-verify",
+                "-data", msg_f.name,
+	        "-in", tsr_f.name,
+		"-CAfile", ca_f.name,
+                "-untrusted", cert_f.name]
+        subprocess.check_call(args)
+
+if '__main__' == __name__:
+   main()
+
+ +

The code fetches the required certificates, store them as temporary +files, timestamp a simple message, store the message and timestamp to +disk and ask 'openssl ts' to verify the timestamp. A timestamp is +around 1.5 kiB in size, and should be fairly easy to store for future +use.

+ +

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

- Tags: 3d-printer, debian, english. + Tags: english, sikkerhet.
@@ -516,30 +404,68 @@ The latter is a fork of the former.

-
Mangler du en skrue, eller har du en skrue løs?
-
4th October 2017
-
Når jeg holder på med ulike prosjekter, så trenger jeg stadig ulike -skruer. Det siste prosjektet jeg holder på med er å lage -en boks til en -HDMI-touch-skjerm som skal brukes med Raspberry Pi. Boksen settes -sammen med skruer og bolter, og jeg har vært i tvil om hvor jeg kan -få tak i de riktige skruene. Clas Ohlson og Jernia i nærheten har -sjelden hatt det jeg trenger. Men her om dagen fikk jeg et fantastisk -tips for oss som bor i Oslo. -Zachariassen Jernvare AS i -Hegermannsgate -23A på Torshov har et fantastisk utvalg, og åpent mellom 09:00 og -17:00. De selger skruer, muttere, bolter, skiver etc i løs vekt, og -så langt har jeg fått alt jeg har lett etter. De har i tillegg det -meste av annen jernvare, som verktøy, lamper, ledninger, etc. Jeg -håper de har nok kunder til å holde det gående lenge, da dette er en -butikk jeg kommer til å besøke ofte. Butikken er et funn å ha i -nabolaget for oss som liker å bygge litt selv. :)

+
Automatic Google Drive sync using grive in Debian
+
4th October 2018
+

A few days, I rescued a Windows victim over to Debian. To try to +rescue the remains, I helped set up automatic sync with Google Drive. +I did not find any sensible Debian package handling this +automatically, so I rebuild the grive2 source from +the Ubuntu UPD8 PPA to do the +task and added a autostart desktop entry and a small shell script to +run in the background while the user is logged in to do the sync. +Here is a sketch of the setup for future reference.

+ +

I first created ~/googledrive, entered the directory and +ran 'grive -a' to authenticate the machine/user. Next, I +created a autostart hook in ~/.config/autostart/grive.desktop +to start the sync when the user log in:

+ +

+[Desktop Entry]
+Name=Google drive autosync
+Type=Application
+Exec=/home/user/bin/grive-sync
+

+ +

Finally, I wrote the ~/bin/grive-sync script to sync +~/googledrive/ with the files in Google Drive.

+ +

+#!/bin/sh
+set -e
+cd ~/
+cleanup() {
+    if [ "$syncpid" ] ; then
+        kill $syncpid
+    fi
+}
+trap cleanup EXIT INT QUIT
+/usr/lib/grive/grive-sync.sh listen googledrive 2>&1 | sed "s%^%$0:%" &
+syncpdi=$!
+while true; do
+    if ! xhost >/dev/null 2>&1 ; then
+        echo "no DISPLAY, exiting as the user probably logged out"
+        exit 1
+    fi
+    if [ ! -e /run/user/1000/grive-sync.sh_googledrive ] ; then
+        /usr/lib/grive/grive-sync.sh sync googledrive
+    fi
+    sleep 300
+done 2>&1 | sed "s%^%$0:%"
+

+ +

Feel free to use the setup if you want. It can be assumed to be +GNU GPL v2 licensed (or any later version, at your leisure), but I +doubt this code is possible to claim copyright on.

+ +

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

- Tags: norsk. + Tags: debian, english.
@@ -547,64 +473,161 @@ nabolaget for oss som liker å bygge litt selv. :)

-
Visualizing GSM radio chatter using gr-gsm and Hopglass
-
29th September 2017
-

Every mobile phone announce its existence over radio to the nearby -mobile cell towers. And this radio chatter is available for anyone -with a radio receiver capable of receiving them. Details about the -mobile phones with very good accuracy is of course collected by the -phone companies, but this is not the topic of this blog post. The -mobile phone radio chatter make it possible to figure out when a cell -phone is nearby, as it include the SIM card ID (IMSI). By paying -attention over time, one can see when a phone arrive and when it leave -an area. I believe it would be nice to make this information more -available to the general public, to make more people aware of how -their phones are announcing their whereabouts to anyone that care to -listen.

- -

I am very happy to report that we managed to get something -visualizing this information up and running for -Oslo Skaperfestival 2017 -(Oslo Makers Festival) taking place today and tomorrow at Deichmanske -library. The solution is based on the -simple -recipe for listening to GSM chatter I posted a few days ago, and -will show up at the stand of Åpen -Sone from the Computer Science department of the University of -Oslo. The presentation will show the nearby mobile phones (aka -IMSIs) as dots in a web browser graph, with lines to the dot -representing mobile base station it is talking to. It was working in -the lab yesterday, and was moved into place this morning.

- -

We set up a fairly powerful desktop machine using Debian -Buster/Testing with several (five, I believe) RTL2838 DVB-T receivers -connected and visualize the visible cell phone towers using an -English version of -Hopglass. A fairly powerfull machine is needed as the -grgsm_livemon_headless processes from -gr-gsm converting -the radio signal to data packages is quite CPU intensive.

- -

The frequencies to listen to, are identified using a slightly -patched scan-and-livemon (to set the --args values for each receiver), -and the Hopglass data is generated using the -patches -in my meshviewer-output branch. For some reason we could not get -more than four SDRs working. There is also a geographical map trying -to show the location of the base stations, but I believe their -coordinates are hardcoded to some random location in Germany, I -believe. The code should be replaced with code to look up location in -a text file, a sqlite database or one of the online databases -mentioned in -the github -issue for the topic. - -

If this sound interesting, visit the stand at the festival!

+
Valutakrambod - A python and bitcoin love story
+
29th September 2018
+

It would come as no surprise to anyone that I am interested in +bitcoins and virtual currencies. I've been keeping an eye on virtual +currencies for many years, and it is part of the reason a few months +ago, I started writing a python library for collecting currency +exchange rates and trade on virtual currency exchanges. I decided to +name the end result valutakrambod, which perhaps can be translated to +small currency shop.

+ +

The library uses the tornado python library to handle HTTP and +websocket connections, and provide a asynchronous system for +connecting to and tracking several services. The code is available +from +github.

+ +

There are two example clients of the library. One is very simple and +list every updated buy/sell price received from the various services. +This code is started by running bin/btc-rates and call the client code +in valutakrambod/client.py. The simple client look like this:

+ +

+import functools
+import tornado.ioloop
+import valutakrambod
+class SimpleClient(object):
+    def __init__(self):
+        self.services = []
+        self.streams = []
+        pass
+    def newdata(self, service, pair, changed):
+        print("%-15s %s-%s: %8.3f %8.3f" % (
+            service.servicename(),
+            pair[0],
+            pair[1],
+            service.rates[pair]['ask'],
+            service.rates[pair]['bid'])
+        )
+    async def refresh(self, service):
+        await service.fetchRates(service.wantedpairs)
+    def run(self):
+        self.ioloop = tornado.ioloop.IOLoop.current()
+        self.services = valutakrambod.service.knownServices()
+        for e in self.services:
+            service = e()
+            service.subscribe(self.newdata)
+            stream = service.websocket()
+            if stream:
+                self.streams.append(stream)
+            else:
+                # Fetch information from non-streaming services immediately
+                self.ioloop.call_later(len(self.services),
+                                       functools.partial(self.refresh, service))
+                # as well as regularly
+                service.periodicUpdate(60)
+        for stream in self.streams:
+            stream.connect()
+        try:
+            self.ioloop.start()
+        except KeyboardInterrupt:
+            print("Interrupted by keyboard, closing all connections.")
+            pass
+        for stream in self.streams:
+            stream.close()
+

+ +

The library client loops over all known "public" services, +initialises it, subscribes to any updates from the service, checks and +activates websocket streaming if the service provide it, and if no +streaming is supported, fetches information from the service and sets +up a periodic update every 60 seconds. The output from this client +can look like this:

+ +

+Bl3p            BTC-EUR: 5687.110 5653.690
+Bl3p            BTC-EUR: 5687.110 5653.690
+Bl3p            BTC-EUR: 5687.110 5653.690
+Hitbtc          BTC-USD: 6594.560 6593.690
+Hitbtc          BTC-USD: 6594.560 6593.690
+Bl3p            BTC-EUR: 5687.110 5653.690
+Hitbtc          BTC-USD: 6594.570 6593.690
+Bitstamp        EUR-USD:    1.159    1.154
+Hitbtc          BTC-USD: 6594.570 6593.690
+Hitbtc          BTC-USD: 6594.580 6593.690
+Hitbtc          BTC-USD: 6594.580 6593.690
+Hitbtc          BTC-USD: 6594.580 6593.690
+Bl3p            BTC-EUR: 5687.110 5653.690
+Paymium         BTC-EUR: 5680.000 5620.240
+

+ +

The exchange order book is tracked in addition to the best buy/sell +price, for those that need to know the details.

+ +

The other example client is focusing on providing a curses view +with updated buy/sell prices as soon as they are received from the +services. This code is located in bin/btc-rates-curses and activated +by using the '-c' argument. Without the argument the "curses" output +is printed without using curses, which is useful for debugging. The +curses view look like this:

+ +

+           Name Pair   Bid         Ask         Spr    Ftcd    Age
+ BitcoinsNorway BTCEUR   5591.8400   5711.0800   2.1%   16    nan     60
+       Bitfinex BTCEUR   5671.0000   5671.2000   0.0%   16     22     59
+        Bitmynt BTCEUR   5580.8000   5807.5200   3.9%   16     41     60
+         Bitpay BTCEUR   5663.2700         nan   nan%   15    nan     60
+       Bitstamp BTCEUR   5664.8400   5676.5300   0.2%    0      1      1
+           Bl3p BTCEUR   5653.6900   5684.9400   0.5%    0    nan     19
+       Coinbase BTCEUR   5600.8200   5714.9000   2.0%   15    nan    nan
+         Kraken BTCEUR   5670.1000   5670.2000   0.0%   14     17     60
+        Paymium BTCEUR   5620.0600   5680.0000   1.1%    1   7515    nan
+ BitcoinsNorway BTCNOK  52898.9700  54034.6100   2.1%   16    nan     60
+        Bitmynt BTCNOK  52960.3200  54031.1900   2.0%   16     41     60
+         Bitpay BTCNOK  53477.7833         nan   nan%   16    nan     60
+       Coinbase BTCNOK  52990.3500  54063.0600   2.0%   15    nan    nan
+        MiraiEx BTCNOK  52856.5300  54100.6000   2.3%   16    nan    nan
+ BitcoinsNorway BTCUSD   6495.5300   6631.5400   2.1%   16    nan     60
+       Bitfinex BTCUSD   6590.6000   6590.7000   0.0%   16     23     57
+         Bitpay BTCUSD   6564.1300         nan   nan%   15    nan     60
+       Bitstamp BTCUSD   6561.1400   6565.6200   0.1%    0      2      1
+       Coinbase BTCUSD   6504.0600   6635.9700   2.0%   14    nan    117
+         Gemini BTCUSD   6567.1300   6573.0700   0.1%   16     89    nan
+         Hitbtc+BTCUSD   6592.6200   6594.2100   0.0%    0      0      0
+         Kraken BTCUSD   6565.2000   6570.9000   0.1%   15     17     58
+  Exchangerates EURNOK      9.4665      9.4665   0.0%   16 107789    nan
+     Norgesbank EURNOK      9.4665      9.4665   0.0%   16 107789    nan
+       Bitstamp EURUSD      1.1537      1.1593   0.5%    4      5      1
+  Exchangerates EURUSD      1.1576      1.1576   0.0%   16 107789    nan
+ BitcoinsNorway LTCEUR      1.0000     49.0000  98.0%   16    nan    nan
+ BitcoinsNorway LTCNOK    492.4800    503.7500   2.2%   16    nan     60
+ BitcoinsNorway LTCUSD      1.0221     49.0000  97.9%   15    nan    nan
+     Norgesbank USDNOK      8.1777      8.1777   0.0%   16 107789    nan
+

+ +

The code for this client is too complex for a simple blog post, so +you will have to check out the git repository to figure out how it +work. What I can tell is how the three last numbers on each line +should be interpreted. The first is how many seconds ago information +was received from the service. The second is how long ago, according +to the service, the provided information was updated. The last is an +estimate on how often the buy/sell values change.

+ +

If you find this library useful, or would like to improve it, I +would love to hear from you. Note that for some of the services I've +implemented a trading API. It might be 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, personvern, surveillance. + Tags: bitcoin, english.
@@ -612,83 +635,47 @@ issue for the topic.
-
Easier recipe to observe the cell phones around you
-
24th September 2017
-

A little more than a month ago I wrote -how -to observe the SIM card ID (aka IMSI number) of mobile phones talking -to nearby mobile phone base stations using Debian GNU/Linux and a -cheap USB software defined radio, and thus being able to pinpoint -the location of people and equipment (like cars and trains) with an -accuracy of a few kilometer. Since then we have worked to make the -procedure even simpler, and it is now possible to do this without any -manual frequency tuning and without building your own packages.

- -

The gr-gsm -package is now included in Debian testing and unstable, and the -IMSI-catcher code no longer require root access to fetch and decode -the GSM data collected using gr-gsm.

- -

Here is an updated recipe, using packages built by Debian and a git -clone of two python scripts:

- -
    - -
  1. Start with a Debian machine running the Buster version (aka - testing).
    2. - -
  2. Run 'apt install gr-gsm python-numpy python-scipy - python-scapy' as root to install required packages.
    3. - -
  3. Fetch the code decoding GSM packages using 'git clone - github.com/Oros42/IMSI-catcher.git'.
    4. - -
  4. Insert USB software defined radio supported by GNU Radio.
    5. - -
  5. Enter the IMSI-catcher directory and run 'python - scan-and-livemon' to locate the frequency of nearby base - stations and start listening for GSM packages on one of them.
    6. - -
  6. Enter the IMSI-catcher directory and run 'python - simple_IMSI-catcher.py' to display the collected information.
    7. - -
- -

Note, due to a bug somewhere the scan-and-livemon program (actually -its underlying -program grgsm_scanner) do not work with the HackRF radio. It does -work with RTL 8232 and other similar USB radio receivers you can get -very cheaply -(for example -from ebay), so for now the solution is to scan using the RTL radio -and only use HackRF for fetching GSM data.

- -

As far as I can tell, a cell phone only show up on one of the -frequencies at the time, so if you are going to track and count every -cell phone around you, you need to listen to all the frequencies used. -To listen to several frequencies, use the --numrecv argument to -scan-and-livemon to use several receivers. Further, I am not sure if -phones using 3G or 4G will show as talking GSM to base stations, so -this approach might not see all phones around you. I typically see -0-400 IMSI numbers an hour when looking around where I live.

- -

I've tried to run the scanner on a -Raspberry Pi 2 and 3 -running Debian Buster, but the grgsm_livemon_headless process seem -to be too CPU intensive to keep up. When GNU Radio print 'O' to -stdout, I am told there it is caused by a buffer overflow between the -radio and GNU Radio, caused by the program being unable to read the -GSM data fast enough. If you see a stream of 'O's from the terminal -where you started scan-and-livemon, you need a give the process more -CPU power. Perhaps someone are able to optimize the code to a point -where it become possible to set up RPi3 based GSM sniffers? I tried -using Raspbian instead of Debian, but there seem to be something wrong -with GNU Radio on raspbian, causing glibc to abort().

+
VLC in Debian now can do bittorrent streaming
+
24th September 2018
+

Back in February, I got curious to see +if +VLC now supported Bittorrent streaming. It did not, despite the +fact that the idea and code to handle such streaming had been floating +around for years. I did however find +a standalone plugin +for VLC to do it, and half a year later I decided to wrap up the +plugin and get it into Debian. I uploaded it to NEW a few days ago, +and am very happy to report that it +entered +Debian a few hours ago, and should be available in Debian/Unstable +tomorrow, and Debian/Testing in a few days.

+ +

With the vlc-plugin-bittorrent package installed you should be able +to stream videos using a simple call to

+ +

+vlc https://archive.org/download/TheGoat/TheGoat_archive.torrent
+

+ +

It can handle magnet links too. Now if only native vlc had +bittorrent support. Then a lot more would be helping each other to +share public domain and creative commons movies. The plugin need some +stability work with seeking and picking the right file in a torrent +with many files, but is already usable. Please note that the plugin +is not removing downloaded files when vlc is stopped, so it can fill +up your disk if you are not careful. Have fun. :)

+ +

I would love to get help maintaining this package. Get in touch if +you are interested.

+ +

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, personvern, surveillance. + Tags: english, verkidetfri, video.
@@ -696,54 +683,35 @@ with GNU Radio on raspbian, causing glibc to abort().

-
Datalagringsdirektivet kaster skygger over Høyre og Arbeiderpartiet
-
7th September 2017
-

For noen dager siden publiserte Jon Wessel-Aas en bloggpost om -«Konklusjonen om datalagring som -EU-kommisjonen ikke ville at vi skulle få se». Det er en -interessant gjennomgang av EU-domstolens syn på snurpenotovervåkning -av befolkningen, som er klar på at det er i strid med -EU-lovgivingen.

- -

Valgkampen går for fullt i Norge, og om noen få dager er siste -frist for å avgi stemme. En ting er sikkert, Høyre og Arbeiderpartiet -får ikke min stemme -denne -gangen heller. Jeg har ikke glemt at de tvang igjennom loven som -skulle pålegge alle data- og teletjenesteleverandører å overvåke alle -sine kunder. En lov som er vedtatt, og aldri opphevet igjen.

- -

Det er tydelig fra diskusjonen rundt grenseløs digital overvåkning -(eller "Digital Grenseforsvar" som det kalles i Orvellisk nytale) at -hverken Høyre og Arbeiderpartiet har noen prinsipielle sperrer mot å -overvåke hele befolkningen, og diskusjonen så langt tyder på at flere -av de andre partiene heller ikke har det. Mange av -de som stemte -for Datalagringsdirektivet i Stortinget (64 fra Arbeiderpartiet, -25 fra Høyre) er fortsatt aktive og argumenterer fortsatt for å radere -vekk mer av innbyggernes privatsfære.

- -

Når myndighetene demonstrerer sin mistillit til folket, tror jeg -folket selv bør legge litt innsats i å verne sitt privatliv, ved å ta -i bruk ende-til-ende-kryptert kommunikasjon med sine kjente og kjære, -og begrense hvor mye privat informasjon som deles med uvedkommende. -Det er jo ingenting som tyder på at myndighetene kommer til å være vår -privatsfære. -Det -er mange muligheter. Selv har jeg litt sans for -Ring, som er basert på p2p-teknologi -uten sentral kontroll, er fri programvare, og støtter meldinger, tale -og video. Systemet er tilgjengelig ut av boksen fra -Debian og -Ubuntu, og det -finnes pakker for Android, MacOSX og Windows. Foreløpig er det få -brukere med Ring, slik at jeg også bruker -Signal som nettleserutvidelse.

+
Using the Kodi API to play Youtube videos
+
2nd September 2018
+

I continue to explore my Kodi installation, and today I wanted to +tell it to play a youtube URL I received in a chat, without having to +insert search terms using the on-screen keyboard. After searching the +web for API access to the Youtube plugin and testing a bit, I managed +to find a recipe that worked. If you got a kodi instance with its API +available from http://kodihost/jsonrpc, you can try the following to +have check out a nice cover band.

+ +

curl --silent --header 'Content-Type: application/json' \
+  --data-binary '{ "id": 1, "jsonrpc": "2.0", "method": "Player.Open",
+  "params": {"item": { "file":
+  "plugin://plugin.video.youtube/play/?video_id=LuRGVM9O0qg" } } }' \
+  http://projector.local/jsonrpc

+ +

I've extended kodi-stream program to take a video source as its +first argument. It can now handle direct video links, youtube links +and 'desktop' to stream my desktop to Kodi. It is almost like a +Chromecast. :)

+ +

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

- Tags: dld, norsk, personvern, stortinget, surveillance, valg. + Tags: debian, english, kodi, video.
@@ -751,96 +719,19 @@ brukere med Ring, slik at jeg også bruker
-
Simpler recipe on how to make a simple $7 IMSI Catcher using Debian
-
9th August 2017
-

On friday, I came across an interesting article in the Norwegian -web based ICT news magazine digi.no on -how -to collect the IMSI numbers of nearby cell phones using the cheap -DVB-T software defined radios. The article refered to instructions -and a recipe by -Keld Norman on Youtube on how to make a simple $7 IMSI Catcher, and I decided to test them out.

- -

The instructions said to use Ubuntu, install pip using apt (to -bypass apt), use pip to install pybombs (to bypass both apt and pip), -and the ask pybombs to fetch and build everything you need from -scratch. I wanted to see if I could do the same on the most recent -Debian packages, but this did not work because pybombs tried to build -stuff that no longer build with the most recent openssl library or -some other version skew problem. While trying to get this recipe -working, I learned that the apt->pip->pybombs route was a long detour, -and the only piece of software dependency missing in Debian was the -gr-gsm package. I also found out that the lead upstream developer of -gr-gsm (the name stand for GNU Radio GSM) project already had a set of -Debian packages provided in an Ubuntu PPA repository. All I needed to -do was to dget the Debian source package and built it.

- -

The IMSI collector is a python script listening for packages on the -loopback network device and printing to the terminal some specific GSM -packages with IMSI numbers in them. The code is fairly short and easy -to understand. The reason this work is because gr-gsm include a tool -to read GSM data from a software defined radio like a DVB-T USB stick -and other software defined radios, decode them and inject them into a -network device on your Linux machine (using the loopback device by -default). This proved to work just fine, and I've been testing the -collector for a few days now.

- -

The updated and simpler recipe is thus to

- -
    - -
  1. start with a Debian machine running Stretch or newer,
    2. - -
  2. build and install the gr-gsm package available from -http://ppa.launchpad.net/ptrkrysik/gr-gsm/ubuntu/pool/main/g/gr-gsm/,
    3. - -
  3. clone the git repostory from https://github.com/Oros42/IMSI-catcher,
    4. - -
  4. run grgsm_livemon and adjust the frequency until the terminal -where it was started is filled with a stream of text (meaning you -found a GSM station).
    5. - -
  5. go into the IMSI-catcher directory and run 'sudo python simple_IMSI-catcher.py' to extract the IMSI numbers.
    6. - -
- -

To make it even easier in the future to get this sniffer up and -running, I decided to package -the gr-gsm project -for Debian (WNPP -#871055), and the package was uploaded into the NEW queue today. -Luckily the gnuradio maintainer has promised to help me, as I do not -know much about gnuradio stuff yet.

- -

I doubt this "IMSI cacher" is anywhere near as powerfull as -commercial tools like -The -Spy Phone Portable IMSI / IMEI Catcher or the -Harris -Stingray, but I hope the existance of cheap alternatives can make -more people realise how their whereabouts when carrying a cell phone -is easily tracked. Seeing the data flow on the screen, realizing that -I live close to a police station and knowing that the police is also -wearing cell phones, I wonder how hard it would be for criminals to -track the position of the police officers to discover when there are -police near by, or for foreign military forces to track the location -of the Norwegian military forces, or for anyone to track the location -of government officials...

- -

It is worth noting that the data reported by the IMSI-catcher -script mentioned above is only a fraction of the data broadcasted on -the GSM network. It will only collect one frequency at the time, -while a typical phone will be using several frequencies, and not all -phones will be using the frequencies tracked by the grgsm_livemod -program. Also, there is a lot of radio chatter being ignored by the -simple_IMSI-catcher script, which would be collected by extending the -parser code. I wonder if gr-gsm can be set up to listen to more than -one frequency?

+
Software created using taxpayers’ money should be Free Software
+
30th August 2018
+

It might seem obvious that software created using tax money should +be available for everyone to use and improve. Free Software +Foundation Europe recentlystarted a campaign to help get more people +to understand this, and I just signed the petition on +Public Money, Public Code to help +them. I hope you too will do the same.

- Tags: debian, english, personvern, surveillance. + Tags: english, opphavsrett.
@@ -855,6 +746,31 @@ one frequency?

Archive