Skip to main content

Feed aggregator

Happy GPL Birthday VLC!

Linux Journal - mer, 02/10/2016 - 15:10

The ever-popular VLC turned 15 a few days ago--that's 15 years since the project was GPLed and released to the world. If we were pedants, we might point out that the project actually came into existence in 1996, but that was a different lifetime. more>>

Catégories: Linux News

Unikernels, Docker, and Why You Should Care

Linux Journal - mar, 02/09/2016 - 13:35

Docker's recent acquisition of Unikernel Systems has sent pulses racing in the microservice world. At the same time, many people have no clue what to make of it, so here's a quick explanation of why this move is a good thing. more>>

Catégories: Linux News

Non-Linux FOSS: Snk

Linux Journal - lun, 02/08/2016 - 13:24

I'm apparently in a silly-game mood this month, because I stumbled across an open-source project I couldn't keep all to myself: Snk. If you remember the classic game of snake, Snk is the same concept, but smaller, harder and with music. more>>

Catégories: Linux News

diff -u: What's New in Kernel Development

Linux Journal - ven, 02/05/2016 - 14:28

The OOM killer is a tough nut to crack. How can a system recover when it's violently thrashing and out of RAM? Once upon a time, you'd just have to reboot. And today, that still might be necessary, but less so, because the OOM killer attempts to identify and stop the process that seems to be causing the hangup. The problem is, it may not choose the right process every time. more>>

Catégories: Linux News

What's New in 3D Printing, Part III: the Software

Linux Journal - jeu, 02/04/2016 - 14:25

This article is the third part of a four-part series that examines some of the changes in 3D printing that have occurred in the past three years since my first articles on the subject. Because this is Linux Journal, instead of discussing the entire 3D printing world, I'm focusing on the sections of the topic most relevant to open source and open hardware. more>>

Catégories: Linux News


Linux Journal - mer, 02/03/2016 - 14:53

My friend and fellow Linux Journalian Kris Occhipinti recently posted a reminder on Facebook for everyone to back up regularly in 2016. Although it's something we already should be doing, if you're not a regular backer-upper, you should start today! more>>

Catégories: Linux News

Giving Silos Their Due

Linux Journal - mar, 02/02/2016 - 14:12

Two things I got way wrong, way back. more>>

Catégories: Linux News

February 2016 Issue of Linux Journal

Linux Journal - lun, 02/01/2016 - 13:39
For the Love of Linux

I love my job. I teach Linux by day and write about Linux at night. It's easy to fall in love with your work when the things you do align with your passions. more>>

Catégories: Linux News

Montréal-Python: Call to Action

Montreal Python - lun, 02/01/2016 - 00:00

Ladies and Gentlemen, we at Montreal Python are super excited for 2016 and we have come up with some great ideas.

In order to turn these ideas into reality, we will need some help. Montreal Python is an open community and collaboration is key to our success. So we are inviting beginners, experts and newcomers to join us at our next organization meeting on Monday February 8th.

Here we will discuss topics about:

  • Annual event / conference
  • Workshops
  • Hackathons / Project nights
  • The future of Montreal Python / elections

Montreal has a pretty exciting Python scene, and thanks to the community that is something we'll maintain for years to come. It is now your chance to come and make things happening.


Monday February 8th at 6pm


Shopify Offices 490 rue de la Gauchetière west


Anyone who want to help or is curious about the Python Community in Montreal

For those that can't attend, don't worry, send us a email with your ideas at

Catégories: External Blogs

My free software activities, January 2016

Anarcat - dim, 01/31/2016 - 17:18
Debian Long Term Support (LTS)

This is my second month working on Debian LTS, started by Raphael Hertzog at Freexian. I think this month has been a little better for me, as I was able to push two "DLA" (Debian LTS Advisories, similar to regular DSAs (Debian Security Advisories) but only applying to LTS releases).

phpMyAdmin and Prosody

I pushed DLAs for phpmyadmin (DLA-406-1) and [prosody (CVE-2016-0756)][]. Both were pretty trivial, but I still had to boot a squeeze VM to test the resulting packages, something that was harder than expected. Still the packages were accepted in squeeze-lts and should work fine.

icu and JDK vulnerabilities

I also spent a good amount of time trying to untangle the mess that java software has become, and in particular the icu vulnerabilities, CVE-2015-4844 and CVE-2016-0494. I ended up being able to backport patches and build packages, not without a significant amount of pain because of how upstream failed to clearly identify which patches did what.

The fact that they (Oracle) did not notify their own upstream (icu) is also a really questionable practice in the free software world, which doesn't come as a surprise coming from Oracle anymore, unfortunately. Even worse, CVE-2016-0494 was actually introduced as part of the fix for CVE-2015-4844. I am not even sure the patches provided actually fix the problem because of course Oracle didn't clearly state what the problem was or how to exploit it.

Still: I did the best I could under the circumstances and built packages which I shared with the debian-lts list in the hope others could test it. I am not much familiar with the icu package or even Java anymore, so I do not feel comfortable uploading those fixes directly right now, especially since I just trust whatever was said on the Redhat and icu bugtrackers. Hopefully someone else can pick this up and confirm I had the right approach.

OpenSSH vulnerabilities

I also worked on CVE-2016-1908 a fairly awkward vulnerability in OpenSSH involving bypassing a security check in the X server that forbids certain clients from looking at keystrokes, selections and more stuff from other clients. The problem is pretty well described in this article. It is, basically, that there are two ways for applications to talk to the X server: "trusted" and "untrusted". If an application is "trusted", they can do all sorts of stuff like manipulate the clipboard, send keystrokes to other applications, sniff keystrokes and so on. This seems fine if you are running local apps (a good example is xdotool to test this) but can be pretty bad once X forwarding comes in play in SSH because then the remote server can use your X credentials to run arbitrary X code in your local X server. In other words, once you forward X, you trust the remote server as being local, more or less.

This is why OpenSSH 3.8 introduced the distinction between -X (untrusted) and -Y (trusted). Unfortunately, after quite a bit of research and work to reproduce the issue (i could not not reproduce the issue!), I realized that Debian has, even since 3.8 has been released (around the "sarge" days!) forcibly defaulted ForwardX11Trusted to yes which makes -X and -Y behave the same way. I described all of this in a post to the LTS list and OpenSSH maintainers and it seems there were good reasons for this back then (-X actually breaks a lot of X clients, for example selecting text will crash xterm), but I still don't quite see why we shouldn't tell people to use -Y consciously if they need to, instead of defaulting to the nasty insecure behavior.

Anyways, this will probably end up being swept under the rug for usability reasons, but just keep in mind that -X can be pretty nasty if you run it against an untrusted server.

Xscreensaver vulnerability

This one was fun. JWZ finally got bitten by his own rants and a pretty embarrassing vulnerability (CVE-2015-8025) that allowed one to crash the login dialog (and unlock the screen) by hot swapping external monitors (!). I worked on trying to reproduce the issue (I couldn't: my HDMI connector stopped working on my laptop, presumably because of a Linux kernel backport) and building the patches provided by the maintainer on wheezy, and pushed debdiffs to the security team which proceeded with the upload.

Other LTS work

I still spend a bit too much time to my taste trying to find work in LTS land. Very often, all the issues are assigned or the ones that remain seem impossible to fix (like the icu vulnerabilities) or packages so big that I am scared to work on it (like eglibc). Still, the last week of work was much better, thanks to the excellent work that Guido Günther has done on the front desk duties this week. My turn is coming up next week and I hope I can do the same for my fellow LTS workers.

Oh, and I tried to reproduce the cpio issue (CVE-2016-2037) and failed, because I didn't know enough about Valgrind. But even then, I don't exactly know where to start to fix that issue. It seems no one does, because this unmaintained package is still not fixed anywhere...

systemd-nspawn adventures

In testing the OpenSSH, phpMyAdmin and prosody issues, I had high hopes that systemd-nspawn would enable me to run an isolated squeeze container reliably. But I had trouble: for some reason, squeeze does not seem to like nspawn at all. First off, it completely refuses to boot it because it doesn't recognize it as an "OS root directory", which, apparently, need the os-release file (in /etc, but it doesn't say that because it would be too easy):

$ sudo systemd-nspawn -b -D /var/cache/pbuilder/squeeze-amd64-vm Directory /home/pbuilder/squeeze-amd64-vm doesn't look like an OS root directory (os-release file is missing). Refusing.

I just created that as an empty file (it works: i also tried copying it from a Jessie system and "faking" the data in it, but it's not necessary), and then nspawn accepts booting it. The next problem is that it just hangs there: it seems that the getty programs can't talk to the nspawn console:

$ sudo systemd-nspawn -b -D /var/cache/pbuilder/squeeze-amd64-vm Spawning container squeeze-amd64-vm on /home/pbuilder/squeeze-amd64-vm. Press ^] three times within 1s to kill container. /etc/localtime is not a symlink, not updating container timezone. INIT: version 2.88 booting Using makefile-style concurrent boot in runlevel S. Setting the system clock. Cannot access the Hardware Clock via any known method. Use the --debug option to see the details of our search for an access method. Unable to set System Clock to: Sun Jan 31 15:57:31 UTC 2016 ... (warning). Activating swap...done. Setting the system clock. Cannot access the Hardware Clock via any known method. Use the --debug option to see the details of our search for an access method. Unable to set System Clock to: Sun Jan 31 15:57:31 UTC 2016 ... (warning). Activating lvm and md swap...done. Checking file systems...fsck from util-linux-ng 2.17.2 done. Mounting local filesystems...done. Activating swapfile swap...done. Cleaning up temporary files.... Cleaning up temporary files.... INIT: Entering runlevel: 2 Using makefile-style concurrent boot in runlevel 2. INIT: Id "2" respawning too fast: disabled for 5 minutes INIT: Id "1" respawning too fast: disabled for 5 minutes INIT: Id "3" respawning too fast: disabled for 5 minutes INIT: Id "4" respawning too fast: disabled for 5 minutes INIT: Id "5" respawning too fast: disabled for 5 minutes INIT: Id "6" respawning too fast: disabled for 5 minutes INIT: no more processes left in this runlevel

Note that before the INIT messages show up, quite a bit of time passes, around a minute or two. And then the container is just stuck there: no login prompt, no nothing. Turning off the VM is also difficult:

$ sudo machinectl list MACHINE CONTAINER SERVICE squeeze-amd64-vm container nspawn 1 machines listed. $ sudo machinectl status squeeze-amd64-vm squeeze-amd64-vm Since: dim 2016-01-31 10:57:31 EST; 4min 44s ago Leader: 3983 (init) Service: nspawn; class container Root: /home/pbuilder/squeeze-amd64-vm Address: fe80::ee55:f9ff:fec5:f255 2001:1928:1:9:ee55:f9ff:fec5:f255 fe80::ea9a:8fff:fe6e:f60 2001:1928:1:9:ea9a:8fff:fe6e:f60 Unit: machine-squeeze\x2damd64\x2dvm.scope ├─3983 init [2] └─4204 lua /usr/bin/prosody $ sudo machinectl poweroff squeeze-amd64-vm # does nothing $ sudo machinectl terminate squeeze-amd64-vm # also does nothing $ sudo kill 3983 # does nothing $ sudo kill -9 3983 $

So only the latter kill -9 worked:

Container squeeze-amd64-vm terminated by signal KILL.

Pretty annoying! So I ended up doing all my tests in a chroot, which involved shutting down the web server on my laptop (for phpmyadmin) and removing policy-rc.d to allow the services to start in the chroot. That worked, but I would prefer to run that code in a container. I'd be happy to hear how other maintainers are handling this kind of stuff.

For the OpenSSH vulnerability testing, I also wanted to have a X server running from squeeze, something which I found surprisingly hard. I was not able to figure out how to make [qemu][] boot from a directory (the above chroot), so I turned to the Squeeze live images from the cdimage archive. Qemu, for some reason, was not able to boot those either: I would only get a grey screen. So I ended up installing Virtualbox, which worked perfectly, but I'd love to hear how I could handle this better as well.

Other free software work

As usual, I did tons more stuff on the computer this month. Way more than I should, actually. I am trying to take some time to reflect upon my work and life these days, and the computer is more part of the problem than the solution, so those feel like a vice that I can't get rid of more than an accomplishment. Still, you might be interested to know about those, so here they are.

Ledger timetracking

I am tracking the time I work on various issues through the overwhelming org-mode in Emacs. The rationale I had was that I didn't want to bother writing yet another time tracker, having written at least two before. One is the old phpTimeTracker, the other is a rewrite that never got anywhere, and finally, I had to deal with the formidable kProject during my time at All of those made me totally allergic to project trackers, timetrackers, and reinventing the wheel, so I figured it made sense to use an already existing solution.

Plus, org-mode allows me to track todos in a fairly meaningful way and I can punch into todo items fairly transparently. I also had a hunch I could bridge this with ledger, a lightweight accounting tool I started using recently. I was previously using the heavier Gnucash, almost a decade ago - but I really was seduced by the idea of a commandline tool that stores its data in a flat file that I can checkin to git.

How wrong I was! First off, ledger can't read org files out of the box. It's weird, but you need to convert those files into timeclock.el formatted files, which, oddly enough, is a completely different file format, and completely different timetracker. Interestingly, it's a very interesting format. An example:

i 1970-01-01 12:00:00 project test 4h o 1970-01-01 16:00:00

... which makes it possible to write a timetracker with two simple shell aliases:

export TIMELOG=$HOME/.timelog alias ti="echo i `date '+%Y-%m-%d %H:%M:%S'` \$* >>$TIMELOG" alias to="echo o `date '+%Y-%m-%d %H:%M:%S'` >>$TIMELOG"

How's that for simplicity!

So you use John Wiegley's org2tc (or my fork which adds a few improvements) to convert from org to timeclock.el. From there on, a bunch of tools can do reporting on those files, the most interesting being obviously ledger itself, as it can read those files natively (although hledger has trouble including them). So far so good: I can do time tracking very easily and report on my time now!

Now, to turn this into bills and actual accounting, well... it's really much more complicated. To make a long story short, it works, but I really had to pull my hair out and ended up making yet another git repository to demonstrate how that could work. I am now stuck at the actual step of generating bills more automatically, which seems to be a total pain. Previous examples and documentation I found were limited and while I feel that some people are actively doing this, they still have to reveal their magic sauce in a meaningful way. I was told on IRC no one actually achieved converting timeclock.el entries directly into bills...


I have done a small patch to the rom collection browser to turn off an annoying "OK" dialog that would block import of ROMs. This actually was way more involved than expected, considering the size of the patch: I had to export the project to Github since the original repository at Google Code is now archived, just like all Google Code repositories. I hope someone will pick it up from there


I have finally got my small patch for SNI support in Sopel! It turns out they are phasing out their own web module in favor of Requests, something that was refused last year. It seems the Sopel developers finally saw the interest in avoiding the maintenance cost of their own complete HTTP library... in an IRC bot.

Working on this patch, I filed a bug in requests which was promptly fixed.

Feed2tweet and spigot

I already mentioned how I linked this blog to Twitter through the use of feed2tweet. Since then, part of my pull requests and issues were merged and others are still pending.

In the meantime, I figured it would make sense to also post to This turned out to be surprisingly more difficult - the only bridge available would not work very well for me. I also filed a bunch of issues in the hope things would stabilize, but so far I have not made this work properly.

It seems to me that all of this stuff is really just reinventing the wheel. There are pretty neat IM libraries out there, one that is actively developed is libturpial, used in the Turpial client. It currently only supports and Twitter, but if support is implemented, it would all of the above problems at once...


Did I mention how awesome the git-mediawiki remote is? It allows me to clone Mediawiki wikis and transparently read and write to them using usual git commands! I use it to keep a mirror of the amateur radio wiki site, for example, as it makes no sense to me to not have this site available offline. I was trying to mirror Wikivoyage and it would block at 500 pages, so I made a patch to support larger wikis.

Borg resignation

Finally, it is with great sadness that I announce that I have left the Borg backup project. It seems that my views of release and project management are irreconcilable with those of the maintainer of the Attic fork. Those looking for more details and explanations are welcome to look in the issue tracker for the various discussions regarding i18n, the support timeframe and compatibility policy, or to contact me personally.

Catégories: External Blogs

Controversy at the Linux Foundation

Linux Journal - jeu, 01/28/2016 - 15:38

Linux has seen more than its fair share of controversy through the years. And, that's not so surprising. For one thing, the operating system flies in the teeth of deeply entrenched multinational companies. The fact that it stands for users instead of vested interests has drawn more than a little ire as well. more>>

Catégories: Linux News

Don't Burn Your Android Yet

Linux Journal - mar, 01/26/2016 - 13:53

A few days ago, security firm Perception Point released the details of a zero-day exploit in the Linux kernel, which has sparked a wave of panic as the report indicated that millions of Android devices are vulnerable. more>>

Catégories: Linux News

Internet in Cuba

Anarcat - lun, 01/25/2016 - 14:50

A lot has been written about the Internet in Cuba over the years. I have read a few articles, from New York Times' happy support for Google's invasion of Cuba to RSF's dramatic and fairly outdated report about censorship in Cuba. Having written before about Internet censorship in Tunisia, I was curious to see if I could get a feel of what it is like over there, now that a new Castro is in power and the Obama administration has started restoring diplomatic ties with Cuba. With those political changes coming signifying the end of an embargo that has been called genocidal by the Cuban government, it is surprisingly difficult to get fresh information about the current state of affairs.

This article aims to fill that gap in clarifying how the internet works in Cuba, what kind of censorship mechanisms are in place and how to work around them. It also digs more technically into the network architecture and performance. It is published in the hope of providing both Cubans and the rest of the world with a better understanding of their network and, if possible, Cubans ways to access the internet more cheaply or without censorship.

"Censorship" and workarounds

Unfortunately, I have been connected to the internet only through the the Varadero airport and the WiFi of a "full included" resort near Jibacoa. I have to come to assume that this network is likely to be on a segregated, uncensored internet while the rest of the country suffers the wrath of the Internet censorship in Cuba I have seen documented elsewhere.

Through my research, I couldn't find any sort of direct censorship. The Netalyzr tool couldn't find anything significantly wrong with the connection, other than the obvious performance problems related both to the overloaded uplinks of the Cuban internet. I ran an incomplete OONI probe as well, and it seems there was no obvious censorship detected there as well, at least according to folks in the helpful #ooni IRC channel. Tor also works fine, and could be a great way to avoid the global surveillance system described later in this article.

Nevertheless, it still remains to be seen how the internet is censored in the "real" Cuban internet, outside of the tourist designated areas - hopefully future visitors or locals can expand on this using the tools mentioned above, using the regular internet.

Usual care should be taken when using any workaround tools, mentioned in this post or not, as different regimes over the world have accused, detained, tortured and killed sometimes for the mere fact of using or distributing circumvention tools. For example, a Russian developer was arrested and detained in 2001 by United States' FBI for exposing vulnerabilities in the Adobe e-books copy protection mechanisms. Similarly, people distributing Tor and other tools have been arrested during the period prior to the revolution in Tunisia.

The Cuban captive portal

There is, however, a more pernicious and yet very obvious censorship mechanism at work in Cuba: to get access to the internet, you have to go through what seems to be a state-wide captive portal, which I have seen both at the hotel and the airport. It is presumably deployed at all levels of the internet access points.

To get credentials through that portal, you need a username and password which you get by buying a Nauta card. Those cards cost 2$CUC and get you an hour of basically unlimited internet access. That may not seem like a lot for a rich northern hotel party-goer, but for Cubans, it's a lot of money, given that the average monthly salary is around 20$CUC. The system is also pretty annoying to use, because it means you do not get continuous network access: every hour, you need to input a new card, which will obviously make streaming movies and other online activities annoying. It also makes hosting servers basically impossible.

So while Cuba does not have, like China or Iran, a "great firewall", there is definitely a big restriction to going online in Cuba. Indeed, it seems to be how the government ensures that Cubans do not foment too much dissent online: keep the internet slow and inaccessible, and you won't get too many Arab spring / blogger revolutions.

Bypassing the Cuban captive portal

The good news is that it is perfectly possible for Cubans (or at least for a tourist like me with resources outside of the country) to bypass the captive portal. Like many poorly implemented portals, the portal allows DNS traffic to go through, which makes it possible to access the global network for free by using a tool like iodine which tunnels IP traffic over DNS requests.

Of course, the bandwidth and reliability of the connection you get through such a portal is pretty bad. I have regularly seen 80% packet loss and over two minutes of latency:

--- ping statistics --- 163 packets transmitted, 31 received, 80% packet loss, time 162391ms rtt min/avg/max/mdev = 133.700/2669.535/64188.027/11257.336 ms, pipe 65

Still, it allowed me to login to my home server through SSH using Mosh to workaround the reliability issues.

Every once in a while, mosh would get stuck and keep on trying to send packets to probe the server, which would clog the connection even more. So I regularly had to restart the whole stack using these commands:

killall iodine # stop DNS tunnel nmcli n off # turn off wifi to change MAC address macchanger -A wlan0 # change MAC address nmcli n on # turn wifi back on sleep 3 # wait for wifi to settle iodine-client-start # restart DNS tunnel

The Koumbit Wiki has good instructions on how to setup a DNS tunnel. I am wondering if such a public service could be of use for Cubans, although I am not sure how it could be deployed only for Cubans, and what kind of traffic it could support... The fact is that iodine does require a server to operate, and that server must be run on the outside of the censored perimeter, something that Cubans may not be able to afford in the first place.

Another possible way to save money with the captive portal would be to write something that automates connecting and disconnecting from the portal. You would feed that program a list of credentials and it would connect to the portal only on demand, and disconnect as soon as no traffic goes through. There are details on the implementation of the captive portal below that may help future endeavours in that field.

Private information revealed to the captive portal

It should be mentioned, however, that the captive portal has a significant amount of information on clients, which is a direct threat to the online privacy of Cuban internet users. Of course the unique identifiers issued with the Nauta cards can be correlated with your identity, right from the start. For example, I had to give my room number to get a Nauta card issued.

Then the central portal also knows which access point you are connected to. For example, the central portal I was connected to Wifi_Memories_Jibacoa which, for anyone that cares to research, will give them a location of about 20 square meters where I was located when connected (there is only one access point in the whole hotel).

Finally, the central portal also knows my MAC address, a unique identifier for the computer I am using which also reveals which brand of computer I am using (Mac, Lenovo, etc). While this address can be changed, very few people know that, let alone how.

This led me to question whether I would be allowed back in Cuba (or even allowed out!) after publishing this blog post, as it is obvious that I can be easily identified based on the time this article was published, my name and other details. Hopefully the Cuban government will either not notice or not care, but this can be a tricky situation, obviously. I have heard that Cuban prisons are not the best hangout place in Cuba, to say the least...

Network configuration assessment

This section is more technical and delves more deeply in the Cuban internet to analyze the quality and topology of the network, along with hints as to which hardware and providers are being used to support the Cuban government.

Line quality

The internet is actually not so bad in the hotel. Again, this may be because of the very fact that I am in that hotel, and I get a privileged access to the new fiber line to Venezuela, the ALBA-1 link.

The line speed I get is around 1mbps, according to speedtest, which selected a server from LIME in George Town, Cayman Islands:

[1034]anarcat@angela:cuba$ speedtest Retrieving configuration... Retrieving server list... Testing from Empresa de Telecomunicaciones de Cuba ( Selecting best server based on latency... Hosted by LIME (George Town) [391.78 km]: 317.546 ms Testing download speed........................................ Download: 1.01 Mbits/s Testing upload speed.................................................. Upload: 1.00 Mbits/s

Latency to the rest of the world is of couse slow:

--- ping statistics --- 122 packets transmitted, 120 received, 1,64% packet loss, time 18731,6ms rtt min/avg/max/sdev = 127,457/156,097/725,211/94,688 ms --- ping statistics --- 122 packets transmitted, 121 received, 0,82% packet loss, time 19371,4ms rtt min/avg/max/sdev = 132,517/160,095/724,971/93,273 ms --- ping statistics --- 122 packets transmitted, 120 received, 1,64% packet loss, time 40748,6ms rtt min/avg/max/sdev = 303,035/339,572/965,092/97,503 ms --- ping statistics --- 122 packets transmitted, 72 received, 40,98% packet loss, time 19560,2ms rtt min/avg/max/sdev = 244,266/271,670/594,104/61,933 ms

Interestingly, Koumbit is actually the closest host in the above test. It could be that Canadian hosts are less affected by bandwidth problems compared to US hosts because of the embargo.

Network topology

The various traceroutes show a fairly odd network topology, but that is typical of what I would described as "colonized internet users", which have layers and layers of NAT and obscure routing that keep them from the real internet. Just like large corporations are implementing NAT in a large scale, Cuba seems to have layers and layers of private RFC 1918 IPv4 space. A typical traceroute starts with:

traceroute to (, 30 hops max, 60 byte packets 1 ( 9.724 ms 9.472 ms 9.405 ms 2 ( 16.089 ms 15.612 ms 15.509 ms 3 ( 15.350 ms 15.805 ms 15.358 ms 4 ( 15.286 ms 14.832 ms 14.405 ms 5 ( 13.734 ms 13.685 ms 14.485 ms 6 ( 14.428 ms 11.393 ms 10.977 ms 7 ( 10.738 ms 10.019 ms 10.326 ms 8 ( 108.577 ms 108.449 ms

Let's take this apart line by line:

1 ( 9.724 ms 9.472 ms 9.405 ms

This is my local gateway, probably the hotel's wifi router.

2 ( 16.089 ms 15.612 ms 15.509 ms

This is likely not very far from the local gateway, probably still in Cuba. It in one bit away from the captive portal IP address (see below) so it is very likely related to the captive portal implementation.

3 ( 15.350 ms 15.805 ms 15.358 ms 4 ( 15.286 ms 14.832 ms 14.405 ms 5 ( 13.734 ms 13.685 ms 14.485 ms

All those are withing RFC 1918 space. Interestingly, the Cuban DNS servers resolve one of those private IPs as within Cuban space, on line #4. That line is interesting because it reveals the potential use of MPLS.

6 ( 14.428 ms 11.393 ms 10.977 ms 7 ( 10.738 ms 10.019 ms 10.326 ms

Those two lines are the only ones that actually reveal that the route belongs in Cuba at all. Both IPs are in a tiny (/24, or 256 IP addresses) network allocated to ETECSA, the state telco in Cuba:

inetnum: 200.0.16/24 status: allocated aut-num: N/A owner: EMPRESA DE TELECOMUNICACIONES DE CUBA S.A. (IXP CUBA) ownerid: CU-CUBA-LACNIC responsible: Rafael López Guerra address: Ave. Independencia y 19 Mayo, s/n, address: 10600 - La Habana - CH country: CU phone: +53 7 574242 [] owner-c: JOQ tech-c: JOQ abuse-c: JEM52 inetrev: 200.0.16/24 nserver: NS1.NAP.ETECSA.NET nsstat: 20160123 AA nslastaa: 20160123 nserver: NS2.NAP.ETECSA.NET nsstat: 20160123 AA nslastaa: 20160123 created: 20030512 changed: 20140610

Then the last hop:

8 ( 108.577 ms 108.449 ms 108.257 ms

...interestingly, lands directly in Toronto, in this case going later to Koumbit but that is the first hop that varies according to the destination, hops 1-7 being a common trunk to all external communications. It's also interesting that this shoves a good 90 milliseconds extra in latency, showing that a significant distance and number of equipment crossed. Yet a single hop is crossed, not showing the intermediate step of the Venezuelan link or any other links for that matter. Something obscure is going on there...

Also interesting to note is the traceroute to the redirection host, which is only one hop away:

traceroute to (, 30 hops max, 60 byte packets 1 ( 6.027 ms 5.698 ms 5.596 ms

Even though it is not the gateway:

$ ip route default via dev wlan0 proto static metric 1024 dev wlan0 proto kernel scope link src dev wlan0 scope link metric 1000

This means a very close coordination between the different access points and the captive portal system. Finally, note that there seems to be only three peers to the Cuban internet: Teleglobe, formerly Canadian, now owned by the Indian [[!wiki Tata group]], and Telefónica, the Spanish Telco that colonized most of Latin America's internet, all the way down to Argentina. This is confirmed by my traceroutes, which show traffic to Koumbit going through Tata and Google's going through Telefónica.

Captive portal implementation

The captive portal is (not accessible outside of Cuba) and uses a self-signed certificate. The domain name resolves to in the hotel.

Accessing gives you a status page which allows you to disconnect from the portal. It actually redirects you to That is also a self-signed, but different certificate. That certificate actually reveals the implication of Gemtek which is a "world-leading provider of Wireless Broadband solutions, offering a wide range of solutions from residential to business". It is somewhat unclear if the implication of Gemtek here is deliberate or a misconfiguration on the part of Cuban officials, especially since the certificate is self-signed and was issued in 2002. It could be, however, a trace of the supposed involvement of China in the development of Cuba's networking systems, although Gemtek is based in Taiwan, and not in the China mainland.

That IP, in turn, redirects you to the same portal but in a page that shows you the statistics:

Notice how you see the MAC address of the machine in the URL (randomized, this is not my MAC address), along with the remaining time, session time, client IP and the Wifi access point ESSID. There may be some potential in defrauding the session time there, I haven't tested it directly.

Hitting Actualizar redirects you back to the IP address, which redirects you to the right URL on the portal. The "real" logout is at:

The login is performed against with a referer of:

Again, notice the information revealed to the central portal.

Equipment and providers

I ran Nmap probes against both the captive portal and the redirection host, in the hope of finding out how they were built and if they could reveal the source of the equipment used.

The complete nmap probes are available in nmap, but it seems that the captive portal is running some embedded device. It is confusing because the probe for the captive portal responds as if it was the gateway, which blurs even more the distinction between the hotel's gateway and the captive portal. This raises the distinct possibility that all access points are actually captive portal that authenticate to another central server.

The nmap traces do show three distinct hosts however:

  • the captive portal (,
  • some redirection host (
  • the hotel's gateway (

They do have distinct signatures so the above may be just me misinterpreting traceroute and nmap results. Your comments may help in clarifying the above.

Still, the three devices show up as running Linux, in the two last cases versions between 2.4.21 and 2.4.31. Now, to find out which version of Linux it is running is way more challenging, and it is possible it is just some custom Linux distribution. Indeed, the webserver shows up as G4200.GSI.2.22.0155 and the SSH server is running OpenSSH 3.0.2p1, which is basically prehistoric (2002!) which corroborates the idea that this is some Gemtek embedded device.

The fact that those devices are running 14 years old software should be a concern to the people responsible for those networks. There is, for example, a remote root vulnerability that affects that specific version of OpenSSH, among many other vulnerabilities.

A note on Nauta card's security

Finally, one can note that it is probably trivial to guess card UIDs. All cards i have here start with the prefix 15100, the following digits being 3576 or 4595, presumably depending on the "batch" that was sent to different hotels, which seems to be batches of 1000 cards. You can also correlate the UID with the date at which the card was issued. For example, 15100357XXX cards are all valid until 19/03/2017, and 151004595XXX cards are all valid until 23/03/2017. Here's the list of UIDs I have seen:

151004595313 151004595974 151003576287 151003576105 151003576097

The passwords, on the other hand, do seem fairly random (although my sample size is small). Interestingly, those passwords are also 12 digits long, which is about as strong as a seven-letter password (mixed uppercase and lowercase). If there are no rate-limiting provisions on that captive portal, it could be possible to guess those passwords, since you have free rein on accessing those routers. Depending on the performance of the routers, you could be lucky and find a working password for free...


Clearly, Internet access in Cuba needs to be modernized. We can clearly see that Cuba years behind the rest of the Americas, if only through the percentage of the population with internet access, or download speeds. The existence of a centralized captive portal also enables a huge surveillance potential that should be a concern for any Cuban, or for that matter, anyone wishing to live in a free society.

The answer, however, lies not in the liberalization of commerce and opening the doors to the US companies and their own systems of surveillance. It should be possible, and even desirable for Cubans to establish their own neutral network, a proposal I have made in the past even for here in Québec. This network could be used and improved by Cubans themselves, prioritizing local communities that would establish their own infrastructure according to their own needs. I have been impressed by this article about the El Paquete system - it shows great innovation and initiative from Cubans which are known for engaging in technology in a creative way. This should be leveraged by letting Cubans do what they want with their networks, not telling them what to do.

The best the Googles of this world can do to help Cuba is not to colonize Cuba's technological landscape but to cleanup their own and make their own tools more easily accessible and shareable offline. It is something companies can do right now, something I detailed in a previous article.

Catégories: External Blogs

New Products

Linux Journal - ven, 01/22/2016 - 12:39
Catégories: Linux News

Firefox OS

Linux Journal - jeu, 01/21/2016 - 12:21

In December 2015, Mozilla announced that its ambitious new operating system would not be appearing on any new phones, but the project may still live on as a platform for smart TVs and IoT devices. more>>

Catégories: Linux News

What's New in 3D Printing, Part II: the Hardware

Linux Journal - mer, 01/20/2016 - 15:48

This is the second article in what will be a four-part series on the current state of 3D printing compared to how things were three years ago when I wrote my first series on 3D printing. Of course, this is Linux Journal, so the focus will be on Linux and open-source-specific aspects in 3D printing. I won't dwell much on proprietary products. more>>

Catégories: Linux News

Wine 1.8 Released

Linux Journal - mar, 01/19/2016 - 14:00

The Wine team members released version 1.8 of their project this week. The project has been in constant development since 1993 and reached version 1 only in 2008, so new releases are major events. more>>

Catégories: Linux News

ABINIT for Chemists

Linux Journal - ven, 01/15/2016 - 14:16

The single largest group of users on high-performance computing clusters has to be the chemists. Their CPU-year count is definitely at the very top of the list. Because of this heavy use, several different packages have become standard tools that most computational chemistry researchers use. more>>

Catégories: Linux News

22 Years of Linux Journal on One DVD - Now Available

Linux Journal - ven, 01/15/2016 - 11:37
22 years of Linux Journal on one DVD. Order yours today and receive $10 off!


Catégories: Linux News

Server Hardening

Linux Journal - jeu, 01/14/2016 - 16:55

Server hardening. The very words conjure up images of tempering soft steel into an unbreakable blade, or taking soft clay and firing it in a kiln, producing a hardened vessel that will last many years. Indeed, server hardening is very much like that. more>>

Catégories: Linux News
Syndiquer le contenu