+ <div class="entry">
+ <div class="title">
+ <a href="http://people.skolelinux.org/pere/blog/Debian_Edu_interview__Roger_Marsal.html">Debian Edu interview: Roger Marsal</a>
+ </div>
+ <div class="date">
+ 30th March 2014
+ </div>
+ <div class="body">
+ <p><a href="http://www.skolelinux.org/">Debian Edu / Skolelinux</a>
+keep gaining new users. Some weeks ago, a person showed up on IRC,
+<a href="irc://irc.debian.org/#debian-edu">#debian-edu</a>, with a
+wish to contribute, and I managed to get a interview with this great
+contributor Roger Marsal to learn more about his background.</p>
+
+<p><strong>Who are you, and how do you spend your days?</strong></p>
+
+<p>My name is Roger Marsal, I'm 27 years old (1986 generation) and I
+live in Barcelona, Spain. I've got a strong business background and I
+work as a patrimony manager and as a real estate agent. Additionally,
+I've co-founded a British based tech company that is nowadays on the
+last development phase of a new social networking concept.</p>
+
+<p>I'm a Linux enthusiast that started its journey with Ubuntu four years
+ago and have recently switched to Debian seeking rock solid stability
+and as a necessary step to gain expertise.</p>
+
+<p>In a nutshell, I spend my days working and learning as much as I
+can to face both my job, entrepreneur project and feed my Linux
+hunger.</p>
+
+<p><strong>How did you get in contact with the Skolelinux / Debian Edu
+project?</strong></p>
+
+<p>I discovered the <a href="http://www.ltsp.org/">LTSP</a> advantages
+with "Ubuntu 12.04 alternate install" and after a year of use I
+started looking for an alternative. Even though I highly value and
+respect the Ubuntu project, I thought it was necessary for me to
+change to a more robust and stable alternative. As far as I was using
+Debian on my personal laptop I thought it would be fine to install
+Debian and configure an LTSP server myself. Surprised, I discovered
+that the Debian project also supported a kind of Edubuntu equivalent,
+and after having some pain I obtained a Debian Edu network up and
+running. I just loved it.</p>
+
+<p><strong>What do you see as the advantages of Skolelinux / Debian
+Edu?</strong></p>
+
+<p>I found a main advantage in that, once you know "the tips and
+tricks", a new installation just works out of the box. It's the most
+complete alternative I've found to create an LTSP network. All the
+other distributions seems to be made of plastic, Debian Edu seems to
+be made of steel.</p>
+
+<p><strong>What do you see as the disadvantages of Skolelinux / Debian
+Edu?</strong></p>
+
+<p>I found two main disadvantages.</p>
+
+<p>I'm not an expert but I've got notions and I had to spent a considerable
+amount of time trying to bring up a standard network topology. I'm quite
+stubborn and I just worked until I did but I'm sure many people with few
+resources (not big schools, but academies for example) would have switched
+or dropped.</p>
+
+<p>It's amazing how such a complex system like Debian Edu has achieved
+this out-of-the-box state. Even though tweaking without breaking gets
+more difficult, as more factors have to be considered. This can
+discourage many people too.</p>
+
+<p><strong>Which free software do you use daily?</strong></p>
+
+<p>I use Debian, Firefox, Okular, Inkscape, LibreOffice and
+Virtualbox.</p>
+
+
+<p><strong>Which strategy do you believe is the right one to use to
+get schools to use free software?</strong></p>
+
+<p>I don't think there is a need for a particular strategy. The free
+attribute in both "freedom" and "no price" meanings is what will
+really bring free software to schools. In my experience I can think of
+the <a href="http://www.r-project.org/">"R" statistical language</a>; a
+few years a ago was an extremely nerd tool for university people.
+Today it's being increasingly used to teach statistics at many
+different level of studies. I believe free and open software will
+increasingly gain popularity, but I'm sure schools will be one of the
+first scenarios where this will happen.</p>
+
+ </div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/intervju">intervju</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
+ <div class="entry">
+ <div class="title">
+ <a href="http://people.skolelinux.org/pere/blog/Dokumentaren_om_Datalagringsdirektivet_sendes_endelig_p__NRK.html">Dokumentaren om Datalagringsdirektivet sendes endelig på NRK</a>
+ </div>
+ <div class="date">
+ 26th March 2014
+ </div>
+ <div class="body">
+ <p><a href="http://www.nuug.no/">Foreningen NUUG</a> melder i natt at
+NRK nå har bestemt seg for
+<a href="http://www.nuug.no/news/NRK_viser_filmen_om_Datalagringsdirektivet_f_rste_gang_2014_03_31.shtml">når
+den norske dokumentarfilmen om datalagringsdirektivet skal
+sendes</a> (se <a href="http://www.imdb.com/title/tt2832844/">IMDB</a>
+for detaljer om filmen) . Første visning blir på NRK2 mandag
+2014-03-31 kl. 19:50, og deretter visninger onsdag 2014-04-02
+kl. 12:30, fredag 2014-04-04 kl. 19:40 og søndag 2014-04-06 kl. 15:10.
+Jeg har sett dokumentaren, og jeg anbefaler enhver å se den selv. Som
+oppvarming mens vi venter anbefaler jeg Bjørn Stærks kronikk i
+Aftenposten fra i går,
+<a href="http://www.aftenposten.no/meninger/kronikker/Autoritar-gjokunge-7514915.html">Autoritær
+gjøkunge</a>, der han gir en grei skisse av hvor ille det står til med
+retten til privatliv og beskyttelsen av demokrati i Norge og resten
+verden, og helt riktig slår fast at det er vi i databransjen som
+sitter med nøkkelen til å gjøre noe med dette. Jeg har involvert meg
+i prosjektene <a href="http://www.dugnadsnett.no/">dugnadsnett.no</a>
+og <a href="https://wiki.debian.org/FreedomBox">FreedomBox</a> for å
+forsøke å gjøre litt selv for å bedre situasjonen, men det er mye
+hardt arbeid fra mange flere enn meg som gjenstår før vi kan sies å ha
+gjenopprettet balansen.</p>
+
+<p>Jeg regner med at nettutgaven dukker opp på
+<a href="http://tv.nrk.no/program/koid75005313/tema-dine-digitale-spor-datalagringsdirektivet">NRKs
+side om filmen om datalagringsdirektivet</a> om fem dager. Hold et
+øye med siden, og tips venner og slekt om at de også bør se den.</p>
+
+ </div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/dld">dld</a>, <a href="http://people.skolelinux.org/pere/blog/tags/freedombox">freedombox</a>, <a href="http://people.skolelinux.org/pere/blog/tags/mesh network">mesh network</a>, <a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk</a>, <a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet</a>, <a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
+ <div class="entry">
+ <div class="title">
+ <a href="http://people.skolelinux.org/pere/blog/Public_Trusted_Timestamping_services_for_everyone.html">Public Trusted Timestamping services for everyone</a>
+ </div>
+ <div class="date">
+ 25th March 2014
+ </div>
+ <div class="body">
+ <p>Did you ever need to store logs or other files in a way that would
+allow it to be used as evidence in court, and needed a way to
+demonstrate without reasonable doubt that the file had not been
+changed since it was created? Or, did you ever need to document that
+a given document was received at some point in time, like some
+archived document or the answer to an exam, and not changed after it
+was received? The problem in these settings is to remove the need to
+trust yourself and your computers, while still being able to prove
+that a file is the same as it was at some given time in the past.</p>
+
+<p>A solution to these problems is to have a trusted third party
+"stamp" the document and verify that at some given time the document
+looked a given way. Such
+<a href="https://en.wikipedia.org/wiki/Notarius">notarius</a> service
+have been around for thousands of years, and its digital equivalent is
+called a
+<a href="http://en.wikipedia.org/wiki/Trusted_timestamping">trusted
+timestamping service</a>. <a href="http://www.ietf.org/">The Internet
+Engineering Task Force</a> standardised how such service could work a
+few years ago as <a href="http://tools.ietf.org/html/rfc3161">RFC
+3161</a>. The mechanism is simple. Create a hash of the file in
+question, send it to a trusted third party which add a time stamp to
+the hash and sign the result with its private key, and send back the
+signed hash + timestamp. Both email, FTP and HTTP can be used to
+request such signature, depending on what is provided by the service
+used. Anyone with the document and the signature can then verify that
+the document matches the signature by creating their own hash and
+checking the signature using the trusted third party public key.
+There are several commercial services around providing such
+timestamping. A quick search for
+"<a href="https://duckduckgo.com/?q=rfc+3161+service">rfc 3161
+service</a>" pointed me to at least
+<a href="https://www.digistamp.com/technical/how-a-digital-time-stamp-works/">DigiStamp</a>,
+<a href="http://www.quovadisglobal.co.uk/CertificateServices/SigningServices/TimeStamp.aspx">Quo
+Vadis</a>,
+<a href="https://www.globalsign.com/timestamp-service/">Global Sign</a>
+and <a href="http://www.globaltrustfinder.com/TSADefault.aspx">Global
+Trust Finder</a>. The system work as long as the private key of the
+trusted third party is not compromised.</p>
+
+<p>But as far as I can tell, there are very few public trusted
+timestamp services available for everyone. I've been looking for one
+for a while now. But yesterday I found one over at
+<a href="https://www.pki.dfn.de/zeitstempeldienst/">Deutches
+Forschungsnetz</a> mentioned in
+<a href="http://www.d-mueller.de/blog/dealing-with-trusted-timestamps-in-php-rfc-3161/">a
+blog by David Müller</a>. I then found
+<a href="http://www.rz.uni-greifswald.de/support/dfn-pki-zertifikate/zeitstempeldienst.html">a
+good recipe on how to use the service</a> over at the University of
+Greifswald.</p>
+
+<p><a href="http://www.openssl.org/">The OpenSSL library</a> contain
+both server and tools to use and set up your own signing service. See
+the ts(1SSL), tsget(1SSL) manual pages for more details. The
+following shell script demonstrate how to extract a signed timestamp
+for any file on the disk in a Debian environment:</p>
+
+<p><blockquote><pre>
+#!/bin/sh
+set -e
+url="http://zeitstempel.dfn.de"
+caurl="https://pki.pca.dfn.de/global-services-ca/pub/cacert/chain.txt"
+reqfile=$(mktemp -t tmp.XXXXXXXXXX.tsq)
+resfile=$(mktemp -t tmp.XXXXXXXXXX.tsr)
+cafile=chain.txt
+if [ ! -f $cafile ] ; then
+ wget -O $cafile "$caurl"
+fi
+openssl ts -query -data "$1" -cert | tee "$reqfile" \
+ | /usr/lib/ssl/misc/tsget -h "$url" -o "$resfile"
+openssl ts -reply -in "$resfile" -text 1>&2
+openssl ts -verify -data "$1" -in "$resfile" -CAfile "$cafile" 1>&2
+base64 < "$resfile"
+rm "$reqfile" "$resfile"
+</pre></blockquote></p>
+
+<p>The argument to the script is the file to timestamp, and the output
+is a base64 encoded version of the signature to STDOUT and details
+about the signature to STDERR. Note that due to
+<a href="http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=742553">a bug
+in the tsget script</a>, you might need to modify the included script
+and remove the last line. Or just write your own HTTP uploader using
+curl. :) Now you too can prove and verify that files have not been
+changed.</p>
+
+<p>But the Internet need more public trusted timestamp services.
+Perhaps something for <a href="http://www.uninett.no/">Uninett</a> or
+my work place the <a href="http://www.uio.no/">University of Oslo</a>
+to set up?</p>
+
+ </div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
+ <div class="entry">
+ <div class="title">
+ <a href="http://people.skolelinux.org/pere/blog/Video_DVD_reader_library___python_dvdvideo___nice_free_software.html">Video DVD reader library / python-dvdvideo - nice free software</a>
+ </div>
+ <div class="date">
+ 21st March 2014
+ </div>
+ <div class="body">
+ <p>Keeping your DVD collection safe from scratches and curious
+children fingers while still having it available when you want to see a
+movie is not straight forward. My preferred method at the moment is
+to store a full copy of the ISO on a hard drive, and use VLC, Popcorn
+Hour or other useful players to view the resulting file. This way the
+subtitles and bonus material are still available and using the ISO is
+just like inserting the original DVD record in the DVD player.</p>
+
+<p>Earlier I used dd for taking security copies, but it do not handle
+DVDs giving read errors (which are quite a few of them). I've also
+tried using
+<a href="http://people.skolelinux.org/pere/blog/Ripping_problematic_DVDs_using_dvdbackup_and_genisoimage.html">dvdbackup
+and genisoimage</a>, but these days I use the marvellous python library
+and program
+<a href="http://bblank.thinkmo.de/blog/new-software-python-dvdvideo">python-dvdvideo</a>
+written by Bastian Blank. It is
+<a href="http://packages.qa.debian.org/p/python-dvdvideo.html">in Debian
+already</a> and the binary package name is python3-dvdvideo. Instead
+of trying to read every block from the DVD, it parses the file
+structure and figure out which block on the DVD is actually in used,
+and only read those blocks from the DVD. This work surprisingly well,
+and I have been able to almost backup my entire DVD collection using
+this method.</p>
+
+<p>So far, python-dvdvideo have failed on between 10 and
+20 DVDs, which is a small fraction of my collection. The most common
+problem is
+<a href="https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=720831">DVDs
+using UTF-16 instead of UTF-8 characters</a>, which according to
+Bastian is against the DVD specification (and seem to cause some
+players to fail too). A rarer problem is what seem to be inconsistent
+DVD structures, as the python library
+<a href="https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=723079">claim
+there is a overlap between objects</a>. An equally rare problem claim
+<a href="https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=741878">some
+value is out of range</a>. No idea what is going on there. I wish I
+knew enough about the DVD format to fix these, to ensure my movie
+collection will stay with me in the future.</p>
+
+<p>So, if you need to keep your DVDs safe, back them up using
+python-dvdvideo. :)</p>
+
+ </div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia</a>, <a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett</a>, <a href="http://people.skolelinux.org/pere/blog/tags/video">video</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
projects / homepage.git / blobdiff