- <title>My own self balancing Lego Segway</title>
- <link>http://people.skolelinux.org/pere/blog/My_own_self_balancing_Lego_Segway.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/My_own_self_balancing_Lego_Segway.html</guid>
- <pubDate>Fri, 4 Nov 2016 10:15:00 +0100</pubDate>
- <description><p>A while back I received a Gyro sensor for the NXT
-<a href="mindstorms.lego.com">Mindstorms</a> controller as a birthday
-present. It had been on my wishlist for a while, because I wanted to
-build a Segway like balancing lego robot. I had already built
-<a href="http://www.nxtprograms.com/NXT2/segway/">a simple balancing
-robot</a> with the kids, using the light/color sensor included in the
-NXT kit as the balance sensor, but it was not working very well. It
-could balance for a while, but was very sensitive to the light
-condition in the room and the reflective properties of the surface and
-would fall over after a short while. I wanted something more robust,
-and had
-<a href="https://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NGY1044">the
-gyro sensor from HiTechnic</a> I believed would solve it on my
-wishlist for some years before it suddenly showed up as a gift from my
-loved ones. :)</p>
-
-<p>Unfortunately I have not had time to sit down and play with it
-since then. But that changed some days ago, when I was searching for
-lego segway information and came across a recipe from HiTechnic for
-building
-<a href="http://www.hitechnic.com/blog/gyro-sensor/htway/">the
-HTWay</a>, a segway like balancing robot. Build instructions and
-<a href="https://www.hitechnic.com/upload/786-HTWayC.nxc">source
-code</a> was included, so it was just a question of putting it all
-together. And thanks to the great work of many Debian developers, the
-compiler needed to build the source for the NXT is already included in
-Debian, so I was read to go in less than an hour. The resulting robot
-do not look very impressive in its simplicity:</p>
-
-<p align="center"><img width="70%" src="http://people.skolelinux.org/pere/blog/images/2016-11-04-lego-htway-robot.jpeg"></p>
-
-<p>Because I lack the infrared sensor used to control the robot in the
-design from HiTechnic, I had to comment out the last task
-(taskControl). I simply placed /* and */ around it get the program
-working without that sensor present. Now it balances just fine until
-the battery status run low:</p>
-
-<p align="center"><video width="70%" controls="true">
- <source src="http://people.skolelinux.org/pere/blog/images/2016-11-04-lego-htway-balancing.ogv" type="video/ogg">
-</video></p>
-
-<p>Now we would like to teach it how to follow a line and take remote
-control instructions using the included Bluetooth receiver in the NXT.</p>
-
-<p>If you, like me, love LEGO and want to make sure we find the tools
-they need to work with LEGO in Debian and all our derivative
-distributions like Ubuntu, check out
-<a href="http://wiki.debian.org/LegoDesigners">the LEGO designers
-project page</a> and join the Debian LEGO team. Personally I own a
-RCX and NXT controller (no EV3), and would like to make sure the
-Debian tools needed to program the systems I own work as they
-should.</p>
-</description>
- </item>
-
- <item>
- <title>Aktivitetsbånd som beskytter privatsfæren</title>
- <link>http://people.skolelinux.org/pere/blog/Aktivitetsb_nd_som_beskytter_privatsf_ren.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Aktivitetsb_nd_som_beskytter_privatsf_ren.html</guid>
- <pubDate>Thu, 3 Nov 2016 09:55:00 +0100</pubDate>
- <description><p>Jeg ble så imponert over
-<a href="https://www.nrk.no/norge/forbrukerradet-mener-aktivitetsarmband-strider-mot-norsk-lov-1.13209079">dagens
-gladnyhet på NRK</a>, om at Forbrukerrådet klager inn vilkårene for
-bruk av aktivitetsbånd fra Fitbit, Garmin, Jawbone og Mio til
-Datatilsynet og forbrukerombudet, at jeg sendte følgende brev til
-forbrukerrådet for å uttrykke min støtte:
-
-<blockquote>
-
-<p>Jeg ble veldig glad over å lese at Forbrukerrådet
-<a href="http://www.forbrukerradet.no/siste-nytt/klager-inn-aktivitetsarmband-for-brudd-pa-norsk-lov/">klager
-inn flere aktivitetsbånd til Datatilsynet for dårlige vilkår</a>. Jeg
-har ønsket meg et aktivitetsbånd som kan måle puls, bevegelse og
-gjerne også andre helserelaterte indikatorer en stund nå. De eneste
-jeg har funnet i salg gjør, som dere også har oppdaget, graverende
-inngrep i privatsfæren og sender informasjonen ut av huset til folk og
-organisasjoner jeg ikke ønsker å dele aktivitets- og helseinformasjon
-med. Jeg ønsker et alternativ som <em>ikke</em> sender informasjon til
-skyen, men derimot bruker
-<a href="http://people.skolelinux.org/pere/blog/Fri_og__pen_standard__slik_Digistan_ser_det.html">en
-fritt og åpent standardisert</a> protokoll (eller i det minste en
-dokumentert protokoll uten patent- og opphavsrettslige
-bruksbegrensinger) til å kommunisere med datautstyr jeg kontrollerer.
-Er jo ikke interessert i å betale noen for å tilrøve seg
-personopplysninger fra meg. Desverre har jeg ikke funnet noe
-alternativ så langt.</p>
-
-<p>Det holder ikke å endre på bruksvilkårene for enhetene, slik
-Datatilsynet ofte legger opp til i sin behandling, når de gjør slik
-f.eks. Fitbit (den jeg har sett mest på). Fitbit krypterer
-informasjonen på enheten og sender den kryptert til leverandøren. Det
-gjør det i praksis umulig både å sjekke hva slags informasjon som
-sendes over, og umulig å ta imot informasjonen selv i stedet for
-Fitbit. Uansett hva slags historie som forteller i bruksvilkårene er
-en jo både prisgitt leverandørens godvilje og at de ikke tvinges av
-sitt lands myndigheter til å lyve til sine kunder om hvorvidt
-personopplysninger spres ut over det bruksvilkårene sier. Det er
-veldokumentert hvordan f.eks. USA tvinger selskaper vha. såkalte
-National security letters til å utlevere personopplysninger samtidig
-som de ikke får lov til å fortelle dette til kundene sine.</p>
-
-<p>Stå på, jeg er veldig glade for at dere har sett på saken. Vet
-dere om aktivitetsbånd i salg i dag som ikke tvinger en til å utlevere
-aktivitets- og helseopplysninger med leverandøren?</p>
-
-</blockquote>
-
-<p>Jeg håper en konkurrent som respekterer kundenes privatliv klarer å
-nå opp i markedet, slik at det finnes et reelt alternativ for oss som
-har full tillit til at skyleverandører vil prioritere egen inntjening
-og myndighetspålegg langt foran kundenes rett til privatliv. Jeg har
-ingen tiltro til at Datatilsynet vil kreve noe mer enn at vilkårene
-endres slik at de forklarer eksplisitt i hvor stor grad bruk av
-produktene utraderer privatsfæren til kundene. Det vil nok gjøre de
-innklagede armbåndene «lovlige», men fortsatt tvinge kundene til å
-dele sine personopplysninger med leverandøren.</p>
-</description>
- </item>
-
- <item>
- <title>Experience and updated recipe for using the Signal app without a mobile phone</title>
- <link>http://people.skolelinux.org/pere/blog/Experience_and_updated_recipe_for_using_the_Signal_app_without_a_mobile_phone.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Experience_and_updated_recipe_for_using_the_Signal_app_without_a_mobile_phone.html</guid>
- <pubDate>Mon, 10 Oct 2016 11:30:00 +0200</pubDate>
- <description><p>In July
-<a href="http://people.skolelinux.org/pere/blog/How_to_use_the_Signal_app_if_you_only_have_a_land_line__ie_no_mobile_phone_.html">I
-wrote how to get the Signal Chrome/Chromium app working</a> without
-the ability to receive SMS messages (aka without a cell phone). It is
-time to share some experiences and provide an updated setup.</p>
-
-<p>The Signal app have worked fine for several months now, and I use
-it regularly to chat with my loved ones. I had a major snag at the
-end of my summer vacation, when the the app completely forgot my
-setup, identity and keys. The reason behind this major mess was
-running out of disk space. To avoid that ever happening again I have
-started storing everything in <tt>userdata/</tt> in git, to be able to
-roll back to an earlier version if the files are wiped by mistake. I
-had to use it once after introducing the git backup. When rolling
-back to an earlier version, one need to use the 'reset session' option
-in Signal to get going, and notify the people you talk with about the
-problem. I assume there is some sequence number tracking in the
-protocol to detect rollback attacks. The git repository is rather big
-(674 MiB so far), but I have not tried to figure out if some of the
-content can be added to a .gitignore file due to lack of spare
-time.</p>
-
-<p>I've also hit the 90 days timeout blocking, and noticed that this
-make it impossible to send messages using Signal. I could still
-receive them, but had to patch the code with a new timestamp to send.
-I believe the timeout is added by the developers to force people to
-upgrade to the latest version of the app, even when there is no
-protocol changes, to reduce the version skew among the user base and
-thus try to keep the number of support requests down.</p>
-
-<p>Since my original recipe, the Signal source code changed slightly,
-making the old patch fail to apply cleanly. Below is an updated
-patch, including the shell wrapper I use to start Signal. The
-original version required a new user to locate the JavaScript console
-and call a function from there. I got help from a friend with more
-JavaScript knowledge than me to modify the code to provide a GUI
-button instead. This mean that to get started you just need to run
-the wrapper and click the 'Register without mobile phone' to get going
-now. I've also modified the timeout code to always set it to 90 days
-in the future, to avoid having to patch the code regularly.</p>
-
-<p>So, the updated recipe for Debian Jessie:</p>
+ <title>Simpler recipe on how to make a simple $7 IMSI Catcher using Debian</title>
+ <link>http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html</guid>
+ <pubDate>Wed, 9 Aug 2017 23:59:00 +0200</pubDate>
+ <description><p>On friday, I came across an interesting article in the Norwegian
+web based ICT news magazine digi.no on
+<a href="https://www.digi.no/artikler/sikkerhetsforsker-lagde-enkel-imsi-catcher-for-60-kroner-na-kan-mobiler-kartlegges-av-alle/398588">how
+to collect the IMSI numbers of nearby cell phones</a> using the cheap
+DVB-T software defined radios. The article refered to instructions
+and <a href="https://www.youtube.com/watch?v=UjwgNd_as30">a recipe by
+Keld Norman on Youtube on how to make a simple $7 IMSI Catcher</a>, and I decided to test them out.</p>
+
+<p>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.</p>
+
+<p>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.</p>
+
+<p>The updated and simpler recipe is thus to</p>