<atom:link href="http://people.skolelinux.org/pere/blog/index.rss" rel="self" type="application/rss+xml" />
<item>
- <title>syslog-trusted-timestamp - chain of trusted timestamps for your syslog</title>
- <link>http://people.skolelinux.org/pere/blog/syslog_trusted_timestamp___chain_of_trusted_timestamps_for_your_syslog.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/syslog_trusted_timestamp___chain_of_trusted_timestamps_for_your_syslog.html</guid>
- <pubDate>Sat, 2 Apr 2016 09:50:00 +0200</pubDate>
- <description><p>Two years ago, I had
-<a href="http://people.skolelinux.org/pere/blog/Public_Trusted_Timestamping_services_for_everyone.html">a
-look at trusted timestamping options available</a>, and among
-other things noted a still open
-<a href="https://bugs.debian.org/742553">bug in the tsget script</a>
-included in openssl that made it harder than necessary to use openssl
-as a trusted timestamping client. A few days ago I was told
-<a href="https:/www.difi.no/">the Norwegian government office DIFI</a> is
-close to releasing their own trusted timestamp service, and in the
-process I was happy to learn about a replacement for the tsget script
-using only curl:</p>
-
-<p><pre>
-openssl ts -query -data "/etc/shells" -cert -sha256 -no_nonce \
- | curl -s -H "Content-Type: application/timestamp-query" \
- --data-binary "@-" http://zeitstempel.dfn.de > etc-shells.tsr
-openssl ts -reply -text -in etc-shells.tsr
-</pre></p>
-
-<p>This produces a binary timestamp file (etc-shells.tsr) which can be
-used to verify that the content of the file /etc/shell with the
-calculated sha256 hash existed at the point in time when the request
-was made. The last command extract the content of the etc-shells.tsr
-in human readable form. The idea behind such timestamp is to be able
-to prove using cryptography that the content of a file have not
-changed since the file was stamped.</p>
-
-<p>To verify that the file on disk match the public key signature in
-the timestamp file, run the following commands. It make sure you have
-the required certificate for the trusted timestamp service available
-and use it to compare the file content with the timestamp. In
-production, one should of course use a better method to verify the
-service certificate.</p>
-
-<p><pre>
-wget -O ca-cert.txt https://pki.pca.dfn.de/global-services-ca/pub/cacert/chain.txt
-openssl ts -verify -data /etc/shells -in etc-shells.tsr -CAfile ca-cert.txt -text
-</pre></p>
-
-<p>Wikipedia have a lot more information about
-<a href="https://en.wikipedia.org/wiki/Trusted_timestamping">trusted
-Timestamping</a> and
-<a href="https://en.wikipedia.org/wiki/Linked_timestamping">linked
-timestamping</a>, and there are several trusted timestamping services
-around, both as commercial services and as free and public services.
-Among the latter is
-<a href="https://www.pki.dfn.de/zeitstempeldienst/">the
-zeitstempel.dfn.de service</a> mentioned above and
-<a href="https://freetsa.org/">freetsa.org service</a> linked to from the
-wikipedia web site. I believe the DIFI service should show up on
-https://tsa.difi.no, but it is not available to the public at the
-moment. I hope this will change when it is into production. The
-<a href="https://tools.ietf.org/html/rfc3161">RFC 3161</a> trusted
-timestamping protocol standard is even implemented in LibreOffice,
-Microsoft Office and Adobe Acrobat, making it possible to verify when
-a document was created.</p>
-
-<p>I would find it useful to be able to use such trusted timestamp
-service to make it possible to verify that my stored syslog files have
-not been tampered with. This is not a new idea. I found one example
-implemented on the Endian network appliances where
-<a href="http://help.endian.com/entries/21518508-Enabling-Timestamping-on-log-files-">the
-configuration of such feature was described in 2012</a>.</p>
-
-<p>But I could not find any free implementation of such feature when I
-searched, so I decided to try to
-<a href="https://github.com/petterreinholdtsen/syslog-trusted-timestamp">build
-a prototype named syslog-trusted-timestamp</a>. My idea is to
-generate a timestamp of the old log files after they are rotated, and
-store the timestamp in the new log file just after rotation. This
-will form a chain that would make it possible to see if any old log
-files are tampered with. But syslog is bad at handling kilobytes of
-binary data, so I decided to base64 encode the timestamp and add an ID
-and line sequence numbers to the base64 data to make it possible to
-reassemble the timestamp file again. To use it, simply run it like
-this:
-
-<p><pre>
-syslog-trusted-timestamp /path/to/list-of-log-files
-</pre></p>
-
-<p>This will send a timestamp from one or more timestamp services (not
-yet decided nor implemented) for each listed file to the syslog using
-logger(1). To verify the timestamp, the same program is used with the
---verify option:</p>
-
-<p><pre>
-syslog-trusted-timestamp --verify /path/to/log-file /path/to/log-with-timestamp
-</pre></p>
-
-<p>The verification step is not yet well designed. The current
-implementation depend on the file path being unique and unchanging,
-and this is not a solid assumption. It also uses process number as
-timestamp ID, and this is bound to create ID collisions. I hope to
-have time to come up with a better way to handle timestamp IDs and
-verification later.</p>
-
-<p>Please check out
-<a href="https://github.com/petterreinholdtsen/syslog-trusted-timestamp">the
-prototype for syslog-trusted-timestamp on github</a> and send
-suggestions and improvement, or let me know if there already exist a
-similar system for timestamping logs already to allow me to join
-forces with others with the same interest.</p>
-
-<p>As usual, if you use Bitcoin and want to show your support of my
-activities, please send Bitcoin donations to my address
-<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
+ <title>First draft Norwegian Bokmål edition of The Debian Administrator's Handbook now public</title>
+ <link>http://people.skolelinux.org/pere/blog/First_draft_Norwegian_Bokm_l_edition_of_The_Debian_Administrator_s_Handbook_now_public.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/First_draft_Norwegian_Bokm_l_edition_of_The_Debian_Administrator_s_Handbook_now_public.html</guid>
+ <pubDate>Tue, 30 Aug 2016 10:10:00 +0200</pubDate>
+ <description><p>In April we
+<a href="http://people.skolelinux.org/pere/blog/Lets_make_a_Norwegian_Bokm_l_edition_of_The_Debian_Administrator_s_Handbook.html">started
+to work</a> on a Norwegian Bokmål edition of the "open access" book on
+how to set up and administrate a Debian system. Today I am happy to
+report that the first draft is now publicly available. You can find
+it on <a href="https://debian-handbook.info/get/">get the Debian
+Administrator's Handbook page</a> (under Other languages). The first
+eight chapters have a first draft translation, and we are working on
+proofreading the content. If you want to help out, please start
+contributing using
+<a href="https://hosted.weblate.org/projects/debian-handbook/">the
+hosted weblate project page</a>, and get in touch using
+<a href="http://lists.alioth.debian.org/mailman/listinfo/debian-handbook-translators">the
+translators mailing list</a>. Please also check out
+<a href="https://debian-handbook.info/contribute/">the instructions for
+contributors</a>. A good way to contribute is to proofread the text
+and update weblate if you find errors.</p>
+
+<p>Our goal is still to make the Norwegian book available on paper as well as
+electronic form.</p>
</description>
</item>
<item>
- <title>Full battery stats collector is now available in Debian</title>
- <link>http://people.skolelinux.org/pere/blog/Full_battery_stats_collector_is_now_available_in_Debian.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Full_battery_stats_collector_is_now_available_in_Debian.html</guid>
- <pubDate>Wed, 23 Mar 2016 22:10:00 +0100</pubDate>
- <description><p>Since this morning, the battery-stats package in Debian include an
-extended collector that will collect the complete battery history for
-later processing and graphing. The original collector store the
-battery level as percentage of last full level, while the new
-collector also record battery vendor, model, serial number, design
-full level, last full level and current battery level. This make it
-possible to predict the lifetime of the battery as well as visualise
-the energy flow when the battery is charging or discharging.</p>
-
-<p>The new tools are available in <tt>/usr/share/battery-stats/</tt>
-in the version 0.5.1 package in unstable. Get the new battery level graph
-and lifetime prediction by running:
-
-<p><pre>
-/usr/share/battery-stats/battery-stats-graph /var/log/battery-stats.csv
-</pre></p>
-
-<p>Or select the 'Battery Level Graph' from your application menu.</p>
-
-<p>The flow in/out of the battery can be seen by running (no menu
-entry yet):</p>
-
-<p><pre>
-/usr/share/battery-stats/battery-stats-graph-flow
-</pre></p>
-
-<p>I'm not quite happy with the way the data is visualised, at least
-when there are few data points. The graphs look a bit better with a
-few years of data.</p>
-
-<p>A while back one important feature I use in the battery stats
-collector broke in Debian. The scripts in
-<tt>/usr/lib/pm-utils/power.d/</tt> were no longer executed. I
-suspect it happened when Jessie started using systemd, but I do not
-know. The issue is reported as
-<a href="https://bugs.debian.org/818649">bug #818649</a> against
-pm-utils. I managed to work around it by adding an udev rule to call
-the collector script every time the power connector is connected and
-disconnected. With this fix in place it was finally time to make a
-new release of the package, and get it into Debian.</p>
-
-<p>If you are interested in how your laptop battery is doing, please
-check out the
-<a href="https://tracker.debian.org/pkg/battery-stats">battery-stats</a>
-in Debian unstable, or rebuild it on Jessie to get it working on
-Debian stable. :) The upstream source is available from
-<a href="https://github.com/petterreinholdtsen/battery-stats">github</a>.
-As always, patches are very welcome.</p>
+ <title>Coz can help you find bottlenecks in multi-threaded software - nice free software</title>
+ <link>http://people.skolelinux.org/pere/blog/Coz_can_help_you_find_bottlenecks_in_multi_threaded_software___nice_free_software.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Coz_can_help_you_find_bottlenecks_in_multi_threaded_software___nice_free_software.html</guid>
+ <pubDate>Thu, 11 Aug 2016 12:00:00 +0200</pubDate>
+ <description><p>This summer, I read a great article
+"<a href="https://www.usenix.org/publications/login/summer2016/curtsinger">coz:
+This Is the Profiler You're Looking For</a>" in USENIX ;login: about
+how to profile multi-threaded programs. It presented a system for
+profiling software by running experiences in the running program,
+testing how run time performance is affected by "speeding up" parts of
+the code to various degrees compared to a normal run. It does this by
+slowing down parallel threads while the "faster up" code is running
+and measure how this affect processing time. The processing time is
+measured using probes inserted into the code, either using progress
+counters (COZ_PROGRESS) or as latency meters (COZ_BEGIN/COZ_END). It
+can also measure unmodified code by measuring complete the program
+runtime and running the program several times instead.</p>
+
+<p>The project and presentation was so inspiring that I would like to
+get the system into Debian. I
+<a href="https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=830708">created
+a WNPP request for it</a> and contacted upstream to try to make the
+system ready for Debian by sending patches. The build process need to
+be changed a bit to avoid running 'git clone' to get dependencies, and
+to include the JavaScript web page used to visualize the collected
+profiling information included in the source package.
+But I expect that should work out fairly soon.</p>
+
+<p>The way the system work is fairly simple. To run an coz experiment
+on a binary with debug symbols available, start the program like this:
+
+<p><blockquote><pre>
+coz run --- program-to-run
+</pre></blockquote></p>
+
+<p>This will create a text file profile.coz with the instrumentation
+information. To show what part of the code affect the performance
+most, use a web browser and either point it to
+<a href="http://plasma-umass.github.io/coz/">http://plasma-umass.github.io/coz/</a>
+or use the copy from git (in the gh-pages branch). Check out this web
+site to have a look at several example profiling runs and get an idea what the end result from the profile runs look like. To make the
+profiling more useful you include &lt;coz.h&gt; and insert the
+COZ_PROGRESS or COZ_BEGIN and COZ_END at appropriate places in the
+code, rebuild and run the profiler. This allow coz to do more
+targeted experiments.</p>
+
+<p>A video published by ACM
+<a href="https://www.youtube.com/watch?v=jE0V-p1odPg">presenting the
+Coz profiler</a> is available from Youtube. There is also a paper
+from the 25th Symposium on Operating Systems Principles available
+titled
+<a href="https://www.usenix.org/conference/atc16/technical-sessions/presentation/curtsinger">Coz:
+finding code that counts with causal profiling</a>.</p>
+
+<p><a href="https://github.com/plasma-umass/coz">The source code</a>
+for Coz is available from github. It will only build with clang
+because it uses a
+<a href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55606">C++
+feature missing in GCC</a>, but I've submitted
+<a href="https://github.com/plasma-umass/coz/pull/67">a patch to solve
+it</a> and hope it will be included in the upstream source soon.</p>
+
+<p>Please get in touch if you, like me, would like to see this piece
+of software in Debian. I would very much like some help with the
+packaging effort, as I lack the in depth knowledge on how to package
+C++ libraries.</p>
</description>
</item>
<item>
- <title>UsingQR - "Electronic" paper invoices using JSON and QR codes</title>
- <link>http://people.skolelinux.org/pere/blog/UsingQR____Electronic__paper_invoices_using_JSON_and_QR_codes.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/UsingQR____Electronic__paper_invoices_using_JSON_and_QR_codes.html</guid>
- <pubDate>Sat, 19 Mar 2016 09:40:00 +0100</pubDate>
- <description><p>Back in 2013 I proposed
-<a href="http://people.skolelinux.org/pere/blog/_Electronic__paper_invoices___using_vCard_in_a_QR_code.html">a
-way to make paper and PDF invoices easier to process electronically by
-adding a QR code with the key information about the invoice</a>. I
-suggested using vCard field definition, to get some standard format
-for name and address, but any format would work. I did not do
-anything about the proposal, but hoped someone one day would make
-something like it. It would make it possible to efficiently send
-machine readable invoices directly between seller and buyer.</p>
-
-<p>This was the background when I came across a proposal and
-specification from the web based accounting and invoicing supplier
-<a href="http://www.visma.com/">Visma</a> in Sweden called
-<a href="http://usingqr.com/">UsingQR</a>. Their PDF invoices contain
-a QR code with the key information of the invoice in JSON format.
-This is the typical content of a QR code following the UsingQR
-specification (based on a real world example, some numbers replaced to
-get a more bogus entry). I've reformatted the JSON to make it easier
-to read. Normally this is all on one long line:</p>
-
-<p><img src="http://people.skolelinux.org/pere/blog/images/2016-03-19-qr-invoice.png" align="right"><pre>
-{
- "vh":500.00,
- "vm":0,
- "vl":0,
- "uqr":1,
- "tp":1,
- "nme":"Din Leverandør",
- "cc":"NO",
- "cid":"997912345 MVA",
- "iref":"12300001",
- "idt":"20151022",
- "ddt":"20151105",
- "due":2500.0000,
- "cur":"NOK",
- "pt":"BBAN",
- "acc":"17202612345",
- "bc":"BIENNOK1",
- "adr":"0313 OSLO"
-}
-</pre></p>
-
-</p>The interpretation of the fields can be found in the
-<a href="http://usingqr.com/wp-content/uploads/2014/06/UsingQR_specification1.pdf">format
-specification</a> (revision 2 from june 2014). The format seem to
-have most of the information needed to handle accounting and payment
-of invoices, at least the fields I have needed so far here in
-Norway.</p>
-
-<p>Unfortunately, the site and document do not mention anything about
-the patent, trademark and copyright status of the format and the
-specification. Because of this, I asked the people behind it back in
-November to clarify. Ann-Christine Savlid (ann-christine.savlid (at)
-visma.com) replied that Visma had not applied for patent or trademark
-protection for this format, and that there were no copyright based
-usage limitations for the format. I urged her to make sure this was
-explicitly written on the web pages and in the specification, but
-unfortunately this has not happened yet. So I guess if there is
-submarine patents, hidden trademarks or a will to sue for copyright
-infringements, those starting to use the UsingQR format might be at
-risk, but if this happen there is some legal defense in the fact that
-the people behind the format claimed it was safe to do so. At least
-with patents, there is always
-<a href="http://www.paperspecs.com/paper-news/beware-the-qr-code-patent-trap/">a
-chance of getting sued...</a></p>
-
-<p>I also asked if they planned to maintain the format in an
-independent standard organization to give others more confidence that
-they would participate in the standardization process on equal terms
-with Visma, but they had no immediate plans for this. Their plan was
-to work with banks to try to get more users of the format, and
-evaluate the way forward if the format proved to be popular. I hope
-they conclude that using an open standard organisation like
-<a href="http://www.ietf.org/">IETF</a> is the correct place to
-maintain such specification.</p>
-
-<p><strong>Update 2016-03-20</strong>: Via Twitter I became aware of
-<a href="https://news.ycombinator.com/item?id=11319492">some comments
-about this blog post</a> that had several useful links and references to
-similar systems. In the Czech republic, the Czech Banking Association
-standard #26, with short name SPAYD, uses QR codes with payment
-information. More information is available from the Wikipedia page on
-<a href="https://en.wikipedia.org/wiki/Short_Payment_Descriptor">Short
-Payment Descriptor</a>. And in Germany, there is a system named
-<a href="http://www.bezahlcode.de/">BezahlCode</a>,
-(<a href="http://www.bezahlcode.de/wp-content/uploads/BezahlCode_TechDok.pdf">specification
-v1.8 2013-12-05 available as PDF</a>), which uses QR codes with
-URL-like formatting using "bank:" as the URI schema/protocol to
-provide the payment information. There is also the
-<a href="http://www.ferd-net.de/front_content.php?idcat=231">ZUGFeRD</a>
-file format that perhaps could be transfered using QR codes, but I am
-not sure if it is done already. Last, in Bolivia there are reports
-that tax information since november 2014 need to be printed in QR
-format on invoices. I have not been able to track down a
-specification for this format, because of my limited language skill
-sets.</p>
+ <title>Sales number for the Free Culture translation, first half of 2016</title>
+ <link>http://people.skolelinux.org/pere/blog/Sales_number_for_the_Free_Culture_translation__first_half_of_2016.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Sales_number_for_the_Free_Culture_translation__first_half_of_2016.html</guid>
+ <pubDate>Fri, 5 Aug 2016 22:45:00 +0200</pubDate>
+ <description><p>As my regular readers probably remember, the last year I published
+a French and Norwegian translation of the classic
+<a href="http://www.free-culture.cc/">Free Culture book</a> by the
+founder of the Creative Commons movement, Lawrence Lessig. A bit less
+known is the fact that due to the way I created the translations,
+using docbook and po4a, I also recreated the English original. And
+because I already had created a new the PDF edition, I published it
+too. The revenue from the books are sent to the Creative Commons
+Corporation. In other words, I do not earn any money from this
+project, I just earn the warm fuzzy feeling that the text is available
+for a wider audience and more people can learn why the Creative
+Commons is needed.</p>
+
+<p>Today, just for fun, I had a look at the sales number over at
+Lulu.com, which take care of payment, printing and shipping. Much to
+my surprise, the English edition is selling better than both the
+French and Norwegian edition, despite the fact that it has been
+available in English since it was first published. In total, 24 paper
+books was sold for USD $19.99 between 2016-01-01 and 2016-07-31:</p>
+
+<table border="0">
+<tr><th>Title / language</th><th>Quantity</th></tr>
+<tr><td><a href="http://www.lulu.com/shop/lawrence-lessig/culture-libre/paperback/product-22645082.html">Culture Libre / French</a></td><td align="right">3</td></tr>
+<tr><td><a href="http://www.lulu.com/shop/lawrence-lessig/fri-kultur/paperback/product-22441576.html">Fri kultur / Norwegian</a></td><td align="right">7</td></tr>
+<tr><td><a href="http://www.lulu.com/shop/lawrence-lessig/free-culture/paperback/product-22440520.html">Free Culture / English</a></td><td align="right">14</td></tr>
+</table>
+
+<p>The books are available both from Lulu.com and from large book
+stores like Amazon and Barnes&Noble. Most revenue, around $10 per
+book, is sent to the Creative Commons project when the book is sold
+directly by Lulu.com. The other channels give less revenue. The
+summary from Lulu tell me 10 books was sold via the Amazon channel, 10
+via Ingram (what is this?) and 4 directly by Lulu. And Lulu.com tells
+me that the revenue sent so far this year is USD $101.42. No idea
+what kind of sales numbers to expect, so I do not know if that is a
+good amount of sales for a 10 year old book or not. But it make me
+happy that the buyers find the book, and I hope they enjoy reading it
+as much as I did.</p>
+
+<p>The ebook edition is available for free from
+<a href="https://github.com/petterreinholdtsen/free-culture-lessig">Github</a>.</p>
+
+<p>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.</p>
</description>
</item>
<item>
- <title>Making battery measurements a little easier in Debian</title>
- <link>http://people.skolelinux.org/pere/blog/Making_battery_measurements_a_little_easier_in_Debian.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Making_battery_measurements_a_little_easier_in_Debian.html</guid>
- <pubDate>Tue, 15 Mar 2016 15:00:00 +0100</pubDate>
- <description><p>Back in September, I blogged about
-<a href="http://people.skolelinux.org/pere/blog/The_life_and_death_of_a_laptop_battery.html">the
-system I wrote to collect statistics about my laptop battery</a>, and
-how it showed the decay and death of this battery (now replaced). I
-created a simple deb package to handle the collection and graphing,
-but did not want to upload it to Debian as there were already
-<a href="https://tracker.debian.org/pkg/battery-stats">a battery-stats
-package in Debian</a> that should do the same thing, and I did not see
-a point of uploading a competing package when battery-stats could be
-fixed instead. I reported a few bugs about its non-function, and
-hoped someone would step in and fix it. But no-one did.</p>
-
-<p>I got tired of waiting a few days ago, and took matters in my own
-hands. The end result is that I am now the new upstream developer of
-battery stats (<a href="https://github.com/petterreinholdtsen/battery-stats">available from github</a>) and part of the team maintaining
-battery-stats in Debian, and the package in Debian unstable is finally
-able to collect battery status using the <tt>/sys/class/power_supply/</tt>
-information provided by the Linux kernel. If you install the
-battery-stats package from unstable now, you will be able to get a
-graph of the current battery fill level, to get some idea about the
-status of the battery. The source package build and work just fine in
-Debian testing and stable (and probably oldstable too, but I have not
-tested). The default graph you get for that system look like this:</p>
-
-<p align="center"><img src="http://people.skolelinux.org/pere/blog/images/2016-03-15-battery-stats-graph-example.png" width="70%" align="center"></p>
-
-<p>My plans for the future is to merge my old scripts into the
-battery-stats package, as my old scripts collected a lot more details
-about the battery. The scripts are merged into the upstream
-battery-stats git repository already, but I am not convinced they work
-yet, as I changed a lot of paths along the way. Will have to test a
-bit more before I make a new release.</p>
-
-<p>I will also consider changing the file format slightly, as I
-suspect the way I combine several values into one field might make it
-impossible to know the type of the value when using it for processing
-and graphing.</p>
-
-<p>If you would like I would like to keep an close eye on your laptop
-battery, check out the battery-stats package in
-<a href="https://tracker.debian.org/pkg/battery-stats">Debian</a> and
-on
-<a href="https://github.com/petterreinholdtsen/battery-stats">github</a>.
-I would love some help to improve the system further.</p>
+ <title>Vitenskapen tar som vanlig feil igjen - relativt feil</title>
+ <link>http://people.skolelinux.org/pere/blog/Vitenskapen_tar_som_vanlig_feil_igjen___relativt_feil.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Vitenskapen_tar_som_vanlig_feil_igjen___relativt_feil.html</guid>
+ <pubDate>Mon, 1 Aug 2016 16:00:00 +0200</pubDate>
+ <description><p>For mange år siden leste jeg en klassisk tekst som gjorde såpass
+inntrykk på meg at jeg husker den fortsatt, flere år senere, og bruker
+argumentene fra den stadig vekk. Teksten var «The Relativity of
+Wrong» som Isaac Asimov publiserte i Skeptical Inquirer i 1989. Den
+gir litt perspektiv rundt formidlingen av vitenskapelige resultater.
+Jeg har hatt lyst til å kunne dele den også med folk som ikke
+behersker engelsk så godt, som barn og noen av mine eldre slektninger,
+og har savnet å ha den tilgjengelig på norsk. For to uker siden tok
+jeg meg sammen og kontaktet Asbjørn Dyrendal i foreningen Skepsis om
+de var interessert i å publisere en norsk utgave på bloggen sin, og da
+han var positiv tok jeg kontakt med Skeptical Inquirer og spurte om
+det var greit for dem. I løpet av noen dager fikk vi tilbakemelding
+fra Barry Karr hos The Skeptical Inquirer som hadde sjekket og fått OK
+fra Robyn Asimov som representerte arvingene i Asmiov-familien og gikk
+igang med oversettingen.</p>
+
+<p>Resultatet, <a href="http://www.skepsis.no/?p=1617">«Relativt
+feil»</a>, ble publisert på skepsis-bloggen for noen minutter siden.
+Jeg anbefaler deg på det varmeste å lese denne teksten og dele den med
+dine venner.</p>
+
+<p>For å håndtere oversettelsen og sikre at original og oversettelse
+var i sync brukte vi git, po4a, GNU make og Transifex. Det hele
+fungerte utmerket og gjorde det enkelt å dele tekstene og jobbe sammen
+om finpuss på formuleringene. Hadde hosted.weblate.org latt meg
+opprette nye prosjekter selv i stedet for å måtte kontakte
+administratoren der, så hadde jeg brukt weblate i stedet.</p>
</description>
</item>
<item>
- <title>Creating, updating and checking debian/copyright semi-automatically</title>
- <link>http://people.skolelinux.org/pere/blog/Creating__updating_and_checking_debian_copyright_semi_automatically.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Creating__updating_and_checking_debian_copyright_semi_automatically.html</guid>
- <pubDate>Fri, 19 Feb 2016 15:00:00 +0100</pubDate>
- <description><p>Making packages for Debian requires quite a lot of attention to
-details. And one of the details is the content of the
-debian/copyright file, which should list all relevant licenses used by
-the code in the package in question, preferably in
-<a href="https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/">machine
-readable DEP5 format</a>.</p>
-
-<p>For large packages with lots of contributors it is hard to write
-and update this file manually, and if you get some detail wrong, the
-package is normally rejected by the ftpmasters. So getting it right
-the first time around get the package into Debian faster, and save
-both you and the ftpmasters some work.. Today, while trying to figure
-out what was wrong with
-<a href="https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=686447">the
-zfsonlinux copyright file</a>, I decided to spend some time on
-figuring out the options for doing this job automatically, or at least
-semi-automatically.</p>
-
-<p>Lucikly, there are at least two tools available for generating the
-file based on the code in the source package,
-<tt><a href="https://tracker.debian.org/pkg/debmake">debmake</a></tt>
-and <tt><a href="https://tracker.debian.org/pkg/cme">cme</a></tt>. I'm
-not sure which one of them came first, but both seem to be able to
-create a sensible draft file. As far as I can tell, none of them can
-be trusted to get the result just right, so the content need to be
-polished a bit before the file is OK to upload. I found the debmake
-option in
-<a href="http://goofying-with-debian.blogspot.com/2014/07/debmake-checking-source-against-dep-5.html">a
-blog posts from 2014</a>.
-
-<p>To generate using debmake, use the -cc option:
+ <title>Techno TV broadcasting live across Norway and the Internet (#debconf16, #nuug) on @frikanalen</title>
+ <link>http://people.skolelinux.org/pere/blog/Techno_TV_broadcasting_live_across_Norway_and_the_Internet___debconf16___nuug__on__frikanalen.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Techno_TV_broadcasting_live_across_Norway_and_the_Internet___debconf16___nuug__on__frikanalen.html</guid>
+ <pubDate>Mon, 1 Aug 2016 10:30:00 +0200</pubDate>
+ <description><p>Did you know there is a TV channel broadcasting talks from DebConf
+16 across an entire country? Or that there is a TV channel
+broadcasting talks by or about
+<a href="http://beta.frikanalen.no/video/625529/">Linus Torvalds</a>,
+<a href="http://beta.frikanalen.no/video/625599/">Tor</a>,
+<a href="http://beta.frikanalen.no/video/624019/">OpenID</A>,
+<a href="http://beta.frikanalen.no/video/625624/">Common Lisp</a>,
+<a href="http://beta.frikanalen.no/video/625446/">Civic Tech</a>,
+<a href="http://beta.frikanalen.no/video/625090/">EFF founder John Barlow</a>,
+<a href="http://beta.frikanalen.no/video/625432/">how to make 3D
+printer electronics</a> and many more fascinating topics? It works
+using only free software (all of it
+<a href="http://github.com/Frikanalen">available from Github</a>), and
+is administrated using a web browser and a web API.</p>
+
+<p>The TV channel is the Norwegian open channel
+<a href="http://www.frikanalen.no/">Frikanalen</a>, and I am involved
+via <a href="https://www.nuug.no/">the NUUG member association</a> in
+running and developing the software for the channel. The channel is
+organised as a member organisation where its members can upload and
+broadcast what they want (think of it as Youtube for national
+broadcasting television). Individuals can broadcast too. The time
+slots are handled on a first come, first serve basis. Because the
+channel have almost no viewers and very few active members, we can
+experiment with TV technology without too much flack when we make
+mistakes. And thanks to the few active members, most of the slots on
+the schedule are free. I see this as an opportunity to spread
+knowledge about technology and free software, and have a script I run
+regularly to fill up all the open slots the next few days with
+technology related video. The end result is a channel I like to
+describe as Techno TV - filled with interesting talks and
+presentations.</p>
+
+<p>It is available on channel 50 on the Norwegian national digital TV
+network (RiksTV). It is also available as a multicast stream on
+Uninett. And finally, it is available as
+<a href="http://beta.frikanalen.no/">a WebM unicast stream</a> from
+Frikanalen and NUUG. Check it out. :)</p>
+</description>
+ </item>
+
+ <item>
+ <title>Unlocking HTC Desire HD on Linux using unruu and fastboot</title>
+ <link>http://people.skolelinux.org/pere/blog/Unlocking_HTC_Desire_HD_on_Linux_using_unruu_and_fastboot.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Unlocking_HTC_Desire_HD_on_Linux_using_unruu_and_fastboot.html</guid>
+ <pubDate>Thu, 7 Jul 2016 11:30:00 +0200</pubDate>
+ <description><p>Yesterday, I tried to unlock a HTC Desire HD phone, and it proved
+to be a slight challenge. Here is the recipe if I ever need to do it
+again. It all started by me wanting to try the recipe to set up
+<a href="https://blog.torproject.org/blog/mission-impossible-hardening-android-security-and-privacy">an
+hardened Android installation</a> from the Tor project blog on a
+device I had access to. It is a old mobile phone with a broken
+microphone The initial idea had been to just
+<a href="http://wiki.cyanogenmod.org/w/Install_CM_for_ace">install
+CyanogenMod on it</a>, but did not quite find time to start on it
+until a few days ago.</p>
+
+<p>The unlock process is supposed to be simple: (1) Boot into the boot
+loader (press volume down and power at the same time), (2) select
+'fastboot' before (3) connecting the device via USB to a Linux
+machine, (4) request the device identifier token by running 'fastboot
+oem get_identifier_token', (5) request the device unlocking key using
+the <a href="http://www.htcdev.com/bootloader/">HTC developer web
+site</a> and unlock the phone using the key file emailed to you.</p>
+
+<p>Unfortunately, this only work fi you have hboot version 2.00.0029
+or newer, and the device I was working on had 2.00.0027. This
+apparently can be easily fixed by downloading a Windows program and
+running it on your Windows machine, if you accept the terms Microsoft
+require you to accept to use Windows - which I do not. So I had to
+come up with a different approach. I got a lot of help from AndyCap
+on #nuug, and would not have been able to get this working without
+him.</p>
+
+<p>First I needed to extract the hboot firmware from
+<a href="http://www.htcdev.com/ruu/PD9810000_Ace_Sense30_S_hboot_2.00.0029.exe">the
+windows binary for HTC Desire HD</a> downloaded as 'the RUU' from HTC.
+For this there is is <a href="https://github.com/kmdm/unruu/">a github
+project named unruu</a> using libunshield. The unshield tool did not
+recognise the file format, but unruu worked and extracted rom.zip,
+containing the new hboot firmware and a text file describing which
+devices it would work for.</p>
+
+<p>Next, I needed to get the new firmware into the device. For this I
+followed some instructions
+<a href="http://www.htc1guru.com/2013/09/new-ruu-zips-posted/">available
+from HTC1Guru.com</a>, and ran these commands as root on a Linux
+machine with Debian testing:</p>
<p><pre>
-debmake -cc > debian/copyright
+adb reboot-bootloader
+fastboot oem rebootRUU
+fastboot flash zip rom.zip
+fastboot flash zip rom.zip
+fastboot reboot
</pre></p>
-<p>Note there are some problems with python and non-ASCII names, so
-this might not be the best option.</p>
+<p>The flash command apparently need to be done twice to take effect,
+as the first is just preparations and the second one do the flashing.
+The adb command is just to get to the boot loader menu, so turning the
+device on while holding volume down and the power button should work
+too.</p>
-<p>The cme option is based on a config parsing library, and I found
-this approach in
-<a href="https://ddumont.wordpress.com/2015/04/05/improving-creation-of-debian-copyright-file/">a
-blog post from 2015</a>. To generate using cme, use the 'update
-dpkg-copyright' option:
+<p>With the new hboot version in place I could start following the
+instructions on the HTC developer web site. I got the device token
+like this:</p>
<p><pre>
-cme update dpkg-copyright
-</pre></p>
-
-<p>This will create or update debian/copyright. The cme tool seem to
-handle UTF-8 names better than debmake.</p>
+fastboot oem get_identifier_token 2>&1 | sed 's/(bootloader) //'
+</pre>
-<p>When the copyright file is created, I would also like some help to
-check if the file is correct. For this I found two good options,
-<tt>debmake -k</tt> and <tt>license-reconcile</tt>. The former seem
-to focus on license types and file matching, and is able to detect
-ineffective blocks in the copyright file. The latter reports missing
-copyright holders and years, but was confused by inconsistent license
-names (like CDDL vs. CDDL-1.0). I suspect it is good to use both and
-fix all issues reported by them before uploading. But I do not know
-if the tools and the ftpmasters agree on what is important to fix in a
-copyright file, so the package might still be rejected.</p>
-
-<p>The devscripts tool <tt>licensecheck</tt> deserve mentioning. It
-will read through the source and try to find all copyright statements.
-It is not comparing the result to the content of debian/copyright, but
-can be useful when verifying the content of the copyright file.</p>
-
-<p>Are you aware of better tools in Debian to create and update
-debian/copyright file. Please let me know, or blog about it on
-planet.debian.org.</p>
-
-<p>As usual, if you use Bitcoin and want to show your support of my
-activities, please send Bitcoin donations to my address
-<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
-
-<p><strong>Update 2016-02-20</strong>: I got a tip from Mike Gabriel
-on how to use licensecheck and cdbs to create a draft copyright file
+<p>And once I got the unlock code via email, I could use it like
+this:</p>
<p><pre>
-licensecheck --copyright -r `find * -type f` | \
- /usr/lib/cdbs/licensecheck2dep5 > debian/copyright.auto
+fastboot flash unlocktoken Unlock_code.bin
</pre></p>
-<p>He mentioned that he normally check the generated file into the
-version control system to make it easier to discover license and
-copyright changes in the upstream source. I will try to do the same
-with my packages in the future.</p>
-
-<p><strong>Update 2016-02-21</strong>: The cme author recommended
-against using -quiet for new users, so I removed it from the proposed
-command line.</p>
+<p>And with that final step in place, the phone was unlocked and I
+could start stuffing the software of my own choosing into the device.
+So far I only inserted a replacement recovery image to wipe the phone
+before I start. We will see what happen next. Perhaps I should
+install <a href="https://www.debian.org/">Debian</a> on it. :)</p>
</description>
</item>
<item>
- <title>Using appstream in Debian to locate packages with firmware and mime type support</title>
- <link>http://people.skolelinux.org/pere/blog/Using_appstream_in_Debian_to_locate_packages_with_firmware_and_mime_type_support.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Using_appstream_in_Debian_to_locate_packages_with_firmware_and_mime_type_support.html</guid>
- <pubDate>Thu, 4 Feb 2016 16:40:00 +0100</pubDate>
- <description><p>The <a href="https://wiki.debian.org/DEP-11">appstream system</a>
-is taking shape in Debian, and one provided feature is a very
-convenient way to tell you which package to install to make a given
-firmware file available when the kernel is looking for it. This can
-be done using apt-file too, but that is for someone else to blog
-about. :)</p>
-
-<p>Here is a small recipe to find the package with a given firmware
-file, in this example I am looking for ctfw-3.2.3.0.bin, randomly
-picked from the set of firmware announced using appstream in Debian
-unstable. In general you would be looking for the firmware requested
-by the kernel during kernel module loading. To find the package
-providing the example file, do like this:</p>
-
-<blockquote><pre>
-% apt install appstream
-[...]
-% apt update
-[...]
-% appstreamcli what-provides firmware:runtime ctfw-3.2.3.0.bin | \
- awk '/Package:/ {print $2}'
-firmware-qlogic
-%
-</pre></blockquote>
-
-<p>See <a href="https://wiki.debian.org/AppStream/Guidelines">the
-appstream wiki</a> page to learn how to embed the package metadata in
-a way appstream can use.</p>
-
-<p>This same approach can be used to find any package supporting a
-given MIME type. This is very useful when you get a file you do not
-know how to handle. First find the mime type using <tt>file
---mime-type</tt>, and next look up the package providing support for
-it. Lets say you got an SVG file. Its MIME type is image/svg+xml,
-and you can find all packages handling this type like this:</p>
-
-<blockquote><pre>
-% apt install appstream
-[...]
-% apt update
-[...]
-% appstreamcli what-provides mimetype image/svg+xml | \
- awk '/Package:/ {print $2}'
-bkchem
-phototonic
-inkscape
-shutter
-tetzle
-geeqie
-xia
-pinta
-gthumb
-karbon
-comix
-mirage
-viewnior
-postr
-ristretto
-kolourpaint4
-eog
-eom
-gimagereader
-midori
-%
-</pre></blockquote>
-
-<p>I believe the MIME types are fetched from the desktop file for
-packages providing appstream metadata.</p>
-</description>
- </item>
-
- <item>
- <title>Creepy, visualise geotagged social media information - nice free software</title>
- <link>http://people.skolelinux.org/pere/blog/Creepy__visualise_geotagged_social_media_information___nice_free_software.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Creepy__visualise_geotagged_social_media_information___nice_free_software.html</guid>
- <pubDate>Sun, 24 Jan 2016 10:50:00 +0100</pubDate>
- <description><p>Most people seem not to realise that every time they walk around
-with the computerised radio beacon known as a mobile phone their
-position is tracked by the phone company and often stored for a long
-time (like every time a SMS is received or sent). And if their
-computerised radio beacon is capable of running programs (often called
-mobile apps) downloaded from the Internet, these programs are often
-also capable of tracking their location (if the app requested access
-during installation). And when these programs send out information to
-central collection points, the location is often included, unless
-extra care is taken to not send the location. The provided
-information is used by several entities, for good and bad (what is
-good and bad, depend on your point of view). What is certain, is that
-the private sphere and the right to free movement is challenged and
-perhaps even eradicated for those announcing their location this way,
-when they share their whereabouts with private and public
-entities.</p>
-
-<p align="center"><img width="70%" src="http://people.skolelinux.org/pere/blog/images/2016-01-24-nice-creepy-desktop-window.png"></p>
-
-<p>The phone company logs provide a register of locations to check out
-when one want to figure out what the tracked person was doing. It is
-unavailable for most of us, but provided to selected government
-officials, company staff, those illegally buying information from
-unfaithful servants and crackers stealing the information. But the
-public information can be collected and analysed, and a free software
-tool to do so is called
-<a href="http://www.geocreepy.com/">Creepy or Cree.py</a>. I
-discovered it when I read
-<a href="http://www.aftenposten.no/kultur/Slik-kan-du-bli-overvaket-pa-Twitter-og-Instagram-uten-a-ane-det-7787884.html">an
-article about Creepy</a> in the Norwegian newspaper Aftenposten i
-November 2014, and decided to check if it was available in Debian.
-The python program was in Debian, but
-<a href="https://tracker.debian.org/pkg/creepy">the version in
-Debian</a> was completely broken and practically unmaintained. I
-uploaded a new version which did not work quite right, but did not
-have time to fix it then. This Christmas I decided to finally try to
-get Creepy operational in Debian. Now a fixed version is available in
-Debian unstable and testing, and almost all Debian specific patches
-are now included
-<a href="https://github.com/jkakavas/creepy">upstream</a>.</p>
-
-<p>The Creepy program visualises geolocation information fetched from
-Twitter, Instagram, Flickr and Google+, and allow one to get a
-complete picture of every social media message posted recently in a
-given area, or track the movement of a given individual across all
-these services. Earlier it was possible to use the search API of at
-least some of these services without identifying oneself, but these
-days it is impossible. This mean that to use Creepy, you need to
-configure it to log in as yourself on these services, and provide
-information to them about your search interests. This should be taken
-into account when using Creepy, as it will also share information
-about yourself with the services.</p>
-
-<p>The picture above show the twitter messages sent from (or at least
-geotagged with a position from) the city centre of Oslo, the capital
-of Norway. One useful way to use Creepy is to first look at
-information tagged with an area of interest, and next look at all the
-information provided by one or more individuals who was in the area.
-I tested it by checking out which celebrity provide their location in
-twitter messages by checkout out who sent twitter messages near a
-Norwegian TV station, and next could track their position over time,
-making it possible to locate their home and work place, among other
-things. A similar technique have been
-<a href="http://www.buzzfeed.com/maxseddon/does-this-soldiers-instagram-account-prove-russia-is-covertl">used
-to locate Russian soldiers in Ukraine</a>, and it is both a powerful
-tool to discover lying governments, and a useful tool to help people
-understand the value of the private information they provide to the
-public.</p>
-
-<p>The package is not trivial to backport to Debian Stable/Jessie, as
-it depend on several python modules currently missing in Jessie (at
-least python-instagram, python-flickrapi and
-python-requests-toolbelt).</p>
-
-<p>(I have uploaded
-<a href="https://screenshots.debian.net/package/creepy">the image to
-screenshots.debian.net</a> and licensed it under the same terms as the
-Creepy program in Debian.)</p>
+ <title>How to use the Signal app if you only have a land line (ie no mobile phone)</title>
+ <link>http://people.skolelinux.org/pere/blog/How_to_use_the_Signal_app_if_you_only_have_a_land_line__ie_no_mobile_phone_.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/How_to_use_the_Signal_app_if_you_only_have_a_land_line__ie_no_mobile_phone_.html</guid>
+ <pubDate>Sun, 3 Jul 2016 14:20:00 +0200</pubDate>
+ <description><p>For a while now, I have wanted to test
+<a href="https://whispersystems.org/">the Signal app</a>, as it is
+said to provide end to end encrypted communication and several of my
+friends and family are already using it. As I by choice do not own a
+mobile phone, this proved to be harder than expected. And I wanted to
+have the source of the client and know that it was the code used on my
+machine. But yesterday I managed to get it working. I used the
+Github source, compared it to the source in
+<a href="https://chrome.google.com/webstore/detail/signal-private-messenger/bikioccmkafdpakkkcpdbppfkghcmihk?hl=en-US">the
+Signal Chrome app</a> available from the Chrome web store, applied
+patches to use the production Signal servers, started the app and
+asked for the hidden "register without a smart phone" form. Here is
+the recipe how I did it.</p>
+
+<p>First, I fetched the Signal desktop source from Github, using
+
+<pre>
+git clone https://github.com/WhisperSystems/Signal-Desktop.git
+</pre>
+
+<p>Next, I patched the source to use the production servers, to be
+able to talk to other Signal users:</p>
+
+<pre>
+cat &lt;&lt;EOF | patch -p0
+diff -ur ./js/background.js userdata/Default/Extensions/bikioccmkafdpakkkcpdbppfkghcmihk/0.15.0_0/js/background.js
+--- ./js/background.js 2016-06-29 13:43:15.630344628 +0200
++++ userdata/Default/Extensions/bikioccmkafdpakkkcpdbppfkghcmihk/0.15.0_0/js/background.js 2016-06-29 14:06:29.530300934 +0200
+@@ -47,8 +47,8 @@
+ });
+ });
+
+- var SERVER_URL = 'https://textsecure-service-staging.whispersystems.org';
+- var ATTACHMENT_SERVER_URL = 'https://whispersystems-textsecure-attachments-staging.s3.amazonaws.com';
++ var SERVER_URL = 'https://textsecure-service-ca.whispersystems.org:4433';
++ var ATTACHMENT_SERVER_URL = 'https://whispersystems-textsecure-attachments.s3.amazonaws.com';
+ var messageReceiver;
+ window.getSocketStatus = function() {
+ if (messageReceiver) {
+diff -ur ./js/expire.js userdata/Default/Extensions/bikioccmkafdpakkkcpdbppfkghcmihk/0.15.0_0/js/expire.js
+--- ./js/expire.js 2016-06-29 13:43:15.630344628 +0200
++++ userdata/Default/Extensions/bikioccmkafdpakkkcpdbppfkghcmihk/0.15.0_0/js/expire.js2016-06-29 14:06:29.530300934 +0200
+@@ -1,6 +1,6 @@
+ ;(function() {
+ 'use strict';
+- var BUILD_EXPIRATION = 0;
++ var BUILD_EXPIRATION = 1474492690000;
+
+ window.extension = window.extension || {};
+
+EOF
+</pre>
+
+<p>The first part is changing the servers, and the second is updating
+an expiration timestamp. This timestamp need to be updated regularly.
+It is set 90 days in the future by the build process (Gruntfile.js).
+The value is seconds since 1970 times 1000, as far as I can tell.</p>
+
+<p>Based on a tip and good help from the #nuug IRC channel, I wrote a
+script to launch Signal in Chromium.</p>
+
+<pre>
+#!/bin/sh
+cd $(dirname $0)
+mkdir -p userdata
+exec chromium \
+ --proxy-server="socks://localhost:9050" \
+ --user-data-dir=`pwd`/userdata --load-and-launch-app=`pwd`
+</pre>
+
+<p> The script start the app and configure Chromium to use the Tor
+SOCKS5 proxy to make sure those controlling the Signal servers (today
+Amazon and Whisper Systems) as well as those listening on the lines
+will have a harder time location my laptop based on the Signal
+connections if they use source IP address.</p>
+
+<p>When the script starts, one need to follow the instructions under
+"Standalone Registration" in the CONTRIBUTING.md file in the git
+repository. I right clicked on the Signal window to get up the
+Chromium debugging tool, visited the 'Console' tab and wrote
+'extension.install("standalone")' on the console prompt to get the
+registration form. Then I entered by land line phone number and
+pressed 'Call'. 5 seconds later the phone rang and a robot voice
+repeated the verification code three times. After entering the number
+into the verification code field in the form, I could start using
+Signal from my laptop.
+
+<p>As far as I can tell, The Signal app will leak who is talking to
+whom and thus who know who to those controlling the central server,
+but such leakage is hard to avoid with a centrally controlled server
+setup. It is something to keep in mind when using Signal - the
+content of your chats are harder to intercept, but the meta data
+exposing your contact network is available to people you do not know.
+So better than many options, but not great. And sadly the usage is
+connected to my land line, thus allowing those controlling the server
+to associate it to my home and person. I would prefer it if only
+those I knew could tell who I was on Signal. There are options
+avoiding such information leakage, but most of my friends are not
+using them, so I am stuck with Signal for now.</p>
</description>
</item>
<item>
- <title>Always download Debian packages using Tor - the simple recipe</title>
- <link>http://people.skolelinux.org/pere/blog/Always_download_Debian_packages_using_Tor___the_simple_recipe.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Always_download_Debian_packages_using_Tor___the_simple_recipe.html</guid>
- <pubDate>Fri, 15 Jan 2016 00:30:00 +0100</pubDate>
- <description><p>During his DebConf15 keynote, Jacob Appelbaum
-<a href="https://summit.debconf.org/debconf15/meeting/331/what-is-to-be-done/">observed
-that those listening on the Internet lines would have good reason to
-believe a computer have a given security hole</a> if it download a
-security fix from a Debian mirror. This is a good reason to always
-use encrypted connections to the Debian mirror, to make sure those
-listening do not know which IP address to attack. In August, Richard
-Hartmann observed that encryption was not enough, when it was possible
-to interfere download size to security patches or the fact that
-download took place shortly after a security fix was released, and
-<a href="http://richardhartmann.de/blog/posts/2015/08/24-Tor-enabled_Debian_mirror/">proposed
-to always use Tor to download packages from the Debian mirror</a>. He
-was not the first to propose this, as the
-<tt><a href="https://tracker.debian.org/pkg/apt-transport-tor">apt-transport-tor</a></tt>
-package by Tim Retout already existed to make it easy to convince apt
-to use <a href="https://www.torproject.org/">Tor</a>, but I was not
-aware of that package when I read the blog post from Richard.</p>
-
-<p>Richard discussed the idea with Peter Palfrader, one of the Debian
-sysadmins, and he set up a Tor hidden service on one of the central
-Debian mirrors using the address vwakviie2ienjx6t.onion, thus making
-it possible to download packages directly between two tor nodes,
-making sure the network traffic always were encrypted.</p>
-
-<p>Here is a short recipe for enabling this on your machine, by
-installing <tt>apt-transport-tor</tt> and replacing http and https
-urls with tor+http and tor+https, and using the hidden service instead
-of the official Debian mirror site. I recommend installing
-<tt>etckeeper</tt> before you start to have a history of the changes
-done in /etc/.</p>
-
-<blockquote><pre>
-apt install apt-transport-tor
-sed -i 's% http://ftp.debian.org/% tor+http://vwakviie2ienjx6t.onion/%' /etc/apt/sources.list
-sed -i 's% http% tor+http%' /etc/apt/sources.list
-</pre></blockquote>
-
-<p>If you have more sources listed in /etc/apt/sources.list.d/, run
-the sed commands for these too. The sed command is assuming your are
-using the ftp.debian.org Debian mirror. Adjust the command (or just
-edit the file manually) to match your mirror.</p>
-
-<p>This work in Debian Jessie and later. Note that tools like
-<tt>apt-file</tt> only recently started using the apt transport
-system, and do not work with these tor+http URLs. For
-<tt>apt-file</tt> you need the version currently in experimental,
-which need a recent apt version currently only in unstable. So if you
-need a working <tt>apt-file</tt>, this is not for you.</p>
-
-<p>Another advantage from this change is that your machine will start
-using Tor regularly and at fairly random intervals (every time you
-update the package lists or upgrade or install a new package), thus
-masking other Tor traffic done from the same machine. Using Tor will
-become normal for the machine in question.</p>
-
-<p>On <a href="https://wiki.debian.org/FreedomBox">Freedombox</a>, APT
-is set up by default to use <tt>apt-transport-tor</tt> when Tor is
-enabled. It would be great if it was the default on any Debian
-system.</p>
+ <title>The new "best" multimedia player in Debian?</title>
+ <link>http://people.skolelinux.org/pere/blog/The_new__best__multimedia_player_in_Debian_.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/The_new__best__multimedia_player_in_Debian_.html</guid>
+ <pubDate>Mon, 6 Jun 2016 12:50:00 +0200</pubDate>
+ <description><p>When I set out a few weeks ago to figure out
+<a href="http://people.skolelinux.org/pere/blog/What_is_the_best_multimedia_player_in_Debian_.html">which
+multimedia player in Debian claimed to support most file formats /
+MIME types</a>, I was a bit surprised how varied the sets of MIME types
+the various players claimed support for. The range was from 55 to 130
+MIME types. I suspect most media formats are supported by all
+players, but this is not really reflected in the MimeTypes values in
+their desktop files. There are probably also some bogus MIME types
+listed, but it is hard to identify which one this is.</p>
+
+<p>Anyway, in the mean time I got in touch with upstream for some of
+the players suggesting to add more MIME types to their desktop files,
+and decided to spend some time myself improving the situation for my
+favorite media player VLC. The fixes for VLC entered Debian unstable
+yesterday. The complete list of MIME types can be seen on the
+<a href="https://wiki.debian.org/DebianMultimedia/PlayerSupport">Multimedia
+player MIME type support status</a> Debian wiki page.</p>
+
+<p>The new "best" multimedia player in Debian? It is VLC, followed by
+totem, parole, kplayer, gnome-mpv, mpv, smplayer, mplayer-gui and
+kmplayer. I am sure some of the other players desktop files support
+several of the formats currently listed as working only with vlc,
+toten and parole.</p>
+
+<p>A sad observation is that only 14 MIME types are listed as
+supported by all the tested multimedia players in Debian in their
+desktop files: audio/mpeg, audio/vnd.rn-realaudio, audio/x-mpegurl,
+audio/x-ms-wma, audio/x-scpls, audio/x-wav, video/mp4, video/mpeg,
+video/quicktime, video/vnd.rn-realvideo, video/x-matroska,
+video/x-ms-asf, video/x-ms-wmv and video/x-msvideo. Personally I find
+it sad that video/ogg and video/webm is not supported by all the media
+players in Debian. As far as I can tell, all of them can handle both
+formats.</p>
</description>
</item>
<item>
- <title>Nedlasting fra NRK, som Matroska med undertekster</title>
- <link>http://people.skolelinux.org/pere/blog/Nedlasting_fra_NRK__som_Matroska_med_undertekster.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Nedlasting_fra_NRK__som_Matroska_med_undertekster.html</guid>
- <pubDate>Sat, 2 Jan 2016 13:50:00 +0100</pubDate>
- <description><p>Det kommer stadig nye løsninger for å ta lagre unna innslag fra NRK
-for å se på det senere. For en stund tilbake kom jeg over et script
-nrkopptak laget av Ingvar Hagelund. Han fjernet riktignok sitt script
-etter forespørsel fra Erik Bolstad i NRK, men noen tok heldigvis og
-gjorde det <a href="https://github.com/liangqi/nrkopptak">tilgjengelig
-via github</a>.</p>
-
-<p>Scriptet kan lagre som MPEG4 eller Matroska, og bake inn
-undertekster i fila på et vis som blant annet VLC forstår. For å
-bruke scriptet, kopier ned git-arkivet og kjør</p>
-
-<p><pre>
-nrkopptak/bin/nrk-opptak k <ahref="https://tv.nrk.no/serie/bmi-turne/MUHH45000115/sesong-1/episode-1">https://tv.nrk.no/serie/bmi-turne/MUHH45000115/sesong-1/episode-1</a>
-</pre></p>
-
-<p>URL-eksemplet er dagens toppsak på tv.nrk.no. Argument 'k' ber
-scriptet laste ned og lagre som Matroska. Det finnes en rekke andre
-muligheter for valg av kvalitet og format.</p>
-
-<p>Jeg foretrekker dette scriptet fremfor youtube-dl, som
-<a href="http://people.skolelinux.org/pere/blog/Hvordan_enkelt_laste_ned_filmer_fra_NRK_med_den__nye__l_sningen.html">
-nevnt i 2014 støtter NRK</a> og en rekke andre videokilder, på grunn
-av at nrkopptak samler undertekster og video i en enkelt fil, hvilket
-gjør håndtering enklere på disk.</p>
+ <title>A program should be able to open its own files on Linux</title>
+ <link>http://people.skolelinux.org/pere/blog/A_program_should_be_able_to_open_its_own_files_on_Linux.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/A_program_should_be_able_to_open_its_own_files_on_Linux.html</guid>
+ <pubDate>Sun, 5 Jun 2016 08:30:00 +0200</pubDate>
+ <description><p>Many years ago, when koffice was fresh and with few users, I
+decided to test its presentation tool when making the slides for a
+talk I was giving for NUUG on Japhar, a free Java virtual machine. I
+wrote the first draft of the slides, saved the result and went to bed
+the day before I would give the talk. The next day I took a plane to
+the location where the meeting should take place, and on the plane I
+started up koffice again to polish the talk a bit, only to discover
+that kpresenter refused to load its own data file. I cursed a bit and
+started making the slides again from memory, to have something to
+present when I arrived. I tested that the saved files could be
+loaded, and the day seemed to be rescued. I continued to polish the
+slides until I suddenly discovered that the saved file could no longer
+be loaded into kpresenter. In the end I had to rewrite the slides
+three times, condensing the content until the talk became shorter and
+shorter. After the talk I was able to pinpoint the problem &ndash;
+kpresenter wrote inline images in a way itself could not understand.
+Eventually that bug was fixed and kpresenter ended up being a great
+program to make slides. The point I'm trying to make is that we
+expect a program to be able to load its own data files, and it is
+embarrassing to its developers if it can't.</p>
+
+<p>Did you ever experience a program failing to load its own data
+files from the desktop file browser? It is not a uncommon problem. A
+while back I discovered that the screencast recorder
+gtk-recordmydesktop would save an Ogg Theora video file the KDE file
+browser would refuse to open. No video player claimed to understand
+such file. I tracked down the cause being <tt>file --mime-type</tt>
+returning the application/ogg MIME type, which no video player I had
+installed listed as a MIME type they would understand. I asked for
+<a href="http://bugs.gw.com/view.php?id=382">file to change its
+behavour</a> and use the MIME type video/ogg instead. I also asked
+several video players to add video/ogg to their desktop files, to give
+the file browser an idea what to do about Ogg Theora files. After a
+while, the desktop file browsers in Debian started to handle the
+output from gtk-recordmydesktop properly.</p>
+
+<p>But history repeats itself. A few days ago I tested the music
+system Rosegarden again, and I discovered that the KDE and xfce file
+browsers did not know what to do with the Rosegarden project files
+(*.rg). I've reported <a href="http://bugs.debian.org/825993">the
+rosegarden problem to BTS</a> and a fix is commited to git and will be
+included in the next upload. To increase the chance of me remembering
+how to fix the problem next time some program fail to load its files
+from the file browser, here are some notes on how to fix it.</p>
+
+<p>The file browsers in Debian in general operates on MIME types.
+There are two sources for the MIME type of a given file. The output from
+<tt>file --mime-type</tt> mentioned above, and the content of the
+shared MIME type registry (under /usr/share/mime/). The file MIME
+type is mapped to programs supporting the MIME type, and this
+information is collected from
+<a href="https://www.freedesktop.org/wiki/Specifications/desktop-entry-spec/">the
+desktop files</a> available in /usr/share/applications/. If there is
+one desktop file claiming support for the MIME type of the file, it is
+activated when asking to open a given file. If there are more, one
+can normally select which one to use by right-clicking on the file and
+selecting the wanted one using 'Open with' or similar. In general
+this work well. But it depend on each program picking a good MIME
+type (preferably
+<a href="http://www.iana.org/assignments/media-types/media-types.xhtml">a
+MIME type registered with IANA</a>), file and/or the shared MIME
+registry recognizing the file and the desktop file to list the MIME
+type in its list of supported MIME types.</p>
+
+<p>The <tt>/usr/share/mime/packages/rosegarden.xml</tt> entry for
+<a href="http://www.freedesktop.org/wiki/Specifications/shared-mime-info-spec">the
+Shared MIME database</a> look like this:</p>
+
+<p><blockquote><pre>
+&lt;?xml version="1.0" encoding="UTF-8"?&gt;
+&lt;mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info"&gt;
+ &lt;mime-type type="audio/x-rosegarden"&gt;
+ &lt;sub-class-of type="application/x-gzip"/&gt;
+ &lt;comment&gt;Rosegarden project file&lt;/comment&gt;
+ &lt;glob pattern="*.rg"/&gt;
+ &lt;/mime-type&gt;
+&lt;/mime-info&gt;
+</pre></blockquote></p>
+
+<p>This states that audio/x-rosegarden is a kind of application/x-gzip
+(it is a gzipped XML file). Note, it is much better to use an
+official MIME type registered with IANA than it is to make up ones own
+unofficial ones like the x-rosegarden type used by rosegarden.</p>
+
+<p>The desktop file of the rosegarden program failed to list
+audio/x-rosegarden in its list of supported MIME types, causing the
+file browsers to have no idea what to do with *.rg files:</p>
+
+<p><blockquote><pre>
+% grep Mime /usr/share/applications/rosegarden.desktop
+MimeType=audio/x-rosegarden-composition;audio/x-rosegarden-device;audio/x-rosegarden-project;audio/x-rosegarden-template;audio/midi;
+X-KDE-NativeMimeType=audio/x-rosegarden-composition
+%
+</pre></blockquote></p>
+
+<p>The fix was to add "audio/x-rosegarden;" at the end of the
+MimeType= line.</p>
+
+<p>If you run into a file which fail to open the correct program when
+selected from the file browser, please check out the output from
+<tt>file --mime-type</tt> for the file, ensure the file ending and
+MIME type is registered somewhere under /usr/share/mime/ and check
+that some desktop file under /usr/share/applications/ is claiming
+support for this MIME type. If not, please report a bug to have it
+fixed. :)</p>
</description>
</item>
<item>
- <title>OpenALPR, find car license plates in video streams - nice free software</title>
- <link>http://people.skolelinux.org/pere/blog/OpenALPR__find_car_license_plates_in_video_streams___nice_free_software.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/OpenALPR__find_car_license_plates_in_video_streams___nice_free_software.html</guid>
- <pubDate>Wed, 23 Dec 2015 01:00:00 +0100</pubDate>
- <description><p>When I was a kid, we used to collect "car numbers", as we used to
-call the car license plate numbers in those days. I would write the
-numbers down in my little book and compare notes with the other kids
-to see how many region codes we had seen and if we had seen some
-exotic or special region codes and numbers. It was a fun game to pass
-time, as we kids have plenty of it.</p>
-
-<p>A few days I came across
-<a href="https://github.com/openalpr/openalpr">the OpenALPR
-project</a>, a free software project to automatically discover and
-report license plates in images and video streams, and provide the
-"car numbers" in a machine readable format. I've been looking for
-such system for a while now, because I believe it is a bad idea that the
-<a href="https://en.wikipedia.org/wiki/Automatic_number_plate_recognition">automatic
-number plate recognition</a> tool only is available in the hands of
-the powerful, and want it to be available also for the powerless to
-even the score when it comes to surveillance and sousveillance. I
-discovered the developer
-<a href="https://bugs.debian.org/747509">wanted to get the tool into
-Debian</a>, and as I too wanted it to be in Debian, I volunteered to
-help him get it into shape to get the package uploaded into the Debian
-archive.</p>
-
-<p>Today we finally managed to get the package into shape and uploaded
-it into Debian, where it currently
-<a href="https://ftp-master.debian.org//new/openalpr_2.2.1-1.html">waits
-in the NEW queue</a> for review by the Debian ftpmasters.</p>
-
-<p>I guess you are wondering why on earth such tool would be useful
-for the common folks, ie those not running a large government
-surveillance system? Well, I plan to put it in a computer on my bike
-and in my car, tracking the cars nearby and allowing me to be notified
-when number plates on my watch list are discovered. Another use case
-was suggested by a friend of mine, who wanted to set it up at his home
-to open the car port automatically when it discovered the plate on his
-car. When I mentioned it perhaps was a bit foolhardy to allow anyone
-capable of placing his license plate number of a piece of cardboard to
-open his car port, men replied that it was always unlocked anyway. I
-guess for such use case it make sense. I am sure there are other use
-cases too, for those with imagination and a vision.</p>
-
-<p>If you want to build your own version of the Debian package, check
-out the upstream git source and symlink ./distros/debian to ./debian/
-before running "debuild" to build the source. Or wait a bit until the
-package show up in unstable.</p>
+ <title>Tor - from its creators mouth 11 years ago</title>
+ <link>http://people.skolelinux.org/pere/blog/Tor___from_its_creators_mouth_11_years_ago.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Tor___from_its_creators_mouth_11_years_ago.html</guid>
+ <pubDate>Sat, 28 May 2016 14:20:00 +0200</pubDate>
+ <description><p>A little more than 11 years ago, one of the creators of Tor, and
+the current President of <a href="https://www.torproject.org/">the Tor
+project</a>, Roger Dingledine, gave a talk for the members of the
+<a href="http://www.nuug.no/">Norwegian Unix User group</a> (NUUG). A
+video of the talk was recorded, and today, thanks to the great help
+from David Noble, I finally was able to publish the video of the talk
+on Frikanalen, the Norwegian open channel TV station where NUUG
+currently publishes its talks. You can
+<a href="http://frikanalen.no/se">watch the live stream using a web
+browser</a> with WebM support, or check out the recording on the video
+on demand page for the talk
+"<a href="http://beta.frikanalen.no/video/625599">Tor: Anonymous
+communication for the US Department of Defence...and you.</a>".</p>
+
+<p>Here is the video included for those of you using browsers with
+HTML video and Ogg Theora support:</p>
+
+<p><video width="70%" poster="http://simula.gunkies.org/media/625599/large_thumb/20050421-tor-frikanalen.jpg" controls>
+ <source src="http://simula.gunkies.org/media/625599/theora/20050421-tor-frikanalen.ogv" type="video/ogg"/>
+</video></p>
+
+<p>I guess the gist of the talk can be summarised quite simply: If you
+want to help the military in USA (and everyone else), use Tor. :)</p>
</description>
</item>
projects / homepage.git / blobdiff