Search Results: "evo"

1 April 2020

Joey Hess: DIN distractions

My offgrid house has an industrial automation panel. A row of electrical devices, mounted on a metal rail. Many wires neatly extend from it above and below, disappearing into wire gutters. I started building this in February, before covid-19 was impacting us here, when lots of mail orders were no big problem, and getting an unusual 3D-printed DIN rail bracket for a SSD was just a couple clicks. I finished a month later, deep into social isolation and quarentine, scrounging around the house for scrap wire, scavenging screws from unused stuff and cutting them to size, and hoping I would not end up in a "need just one more part that I can't get" situation. It got rather elaborate, and working on it was often a welcome distraction from the news when I couldn't concentrate on my usual work. I'm posting this now because people sometimes tell me they like hearing about my offfgrid stuff, and perhaps you could use a distraction too. The panel has my house's computer on it, as well as both AC and DC power distribution, breakers, and switching. Since the house is offgrid, the panel is designed to let every non-essential power drain be turned off, from my offgrid fridge to the 20 terabytes of offline storage to the inverter and satellite dish, the spring pump for my gravity flow water system, and even the power outlet by the kitchen sink. Saving power is part of why I'm using old-school relays and stuff and not IOT devices, the other reason is of course: IOT devices are horrible dystopian e-waste. I'm taking the utopian Star Trek approach, where I can command "full power to the vacuum cleaner!" Two circuit boards, connected by numerous ribbon cables, and clearly hand-soldered. The smaller board is suspended above the larger. An electrical schematic, of moderate complexity. At the core of the panel, next to the cubietruck arm board, is a custom IO daughterboard. Designed and built by hand to fit into a DIN mount case, it uses every GPIO pin on the cubietruck's main GPIO header. Making this board took 40+ hours, and was about half the project. It got pretty tight in there. This was my first foray into DIN rail mount, and it really is industrial lego -- a whole universe of parts that all fit together and are immensely flexible. Often priced more than seems reasonable for a little bit of plastic and metal, until you look at the spec sheets and the ratings. (Total cost for my panel was $400.) It's odd that it's not more used outside its niche -- I came of age in the Bay Area, surrounded by rack mount equipment, but no DIN mount equipment. Hacking the hardware in a rack is unusual, but DIN invites hacking. Admittedly, this is a second system kind of project, replacing some unsightly shelves full of gear and wires everywhere with something kind of overdone. But should be worth it in the long run as new gear gets clipped into place and it evolves for changing needs. Also, wire gutters, where have you been all my life? A cramped utility room with an entire wall covered with electronic gear, including the DIN rail, which is surrounded by wire gutters Detail of a wire gutter with the cover removed. Numerous large and small wires run along it and exit here and there. Finally, if you'd like to know what everything on the DIN rail is, from left to right: Ground block, 24v DC disconnect, fridge GFI, spare GFI, USB hub switch, computer switch, +24v block, -24v block, IO daughterboard, 1tb SSD, arm board, modem, 3 USB hubs, 5 relays, AC hot block, AC neutral block, DC-DC power converters, humidity sensor. Full width of DIN rail.

30 March 2020

Shirish Agarwal: Covid 19 and the Indian response.

There have been lot of stories about Coronavirus and with it a lot of political blame-game has been happening. The first step that India took of a lockdown is and was a good step but without having a plan as to how especially the poor and the needy and especially the huge migrant population that India has (internal migration) be affected by it. A 2019 World Economic Forum shares the stats. as 139 million people. That is a huge amount of people and there are a variety of both push and pull factors which has displaced these huge number of people. While there have been attempts in the past and probably will continue in future they will be hampered unless we have trust-worthy data which is where there is lots that need to be done. In the recent few years, both the primary and secondary data has generated lot of controversies within India as well as abroad so no point in rehashing all of that. Even the definition of who is a migrant needs to be well-established just as who is a farmer . The simplest lucanae in the later is those who have land are known as farmers but the tenant farmers and their wives are not added as farmers hence the true numbers are never known. Is this an India-specific problem or similar definition issues are there in the rest of the world I don t know.

How our Policies fail to reach the poor and the vulnerable The sad part is most policies in India are made in castles in the air . An interview by the wire shares the conundrum of those who are affected and the policies which are enacted for them (it s a youtube video, sorry)
If one with an open and fresh mind sees the interview it is clear that why there was a huge reverse migration from Indian cities to villages. The poor and marginalized has always seen the Indian state as an extortive force so it doesn t make sense for them to be in the cities. The Prime Minister s annoucement of food for 3 months was a clear indication for the migrant population that for 3 months they will have no work. Faced with such a scenario, the best option for them was to return to their native places. While videos of huge number of migrants were shown of Delhi, this was the scenario of most states and cities, including Pune, my own city . Another interesting point which was made is most of the policies will need the migrants to be back in the villages. Most of these are tied to the accounts which are opened in villages, so even if they want to have the benefits they will have to migrate to villages in order to use them. Of course, everybody in India knows how leaky the administration is. The late Shri Rajiv Gandhi had famously and infamously remarked once how leaky the Public Distribution system and such systems are. It s only 10 paise out of rupee which reaches the poor. And he said this about 30 years ago. There have been numerous reports of both IPS (Indian Police Services) reforms and IAS (Indian Administrative Services) reforms over the years, many of the committee reports have been in public domain and in fact was part of the election manifesto of the ruling party in 2014 but no movement has happened on that part. The only thing which has happened is people from the ruling party have been appointed on various posts which is same as earlier governments. I was discussing with a friend who is a contractor and builder about the construction labour issues which were pointed in the report and if it is true that many a times the migrant labour is not counted. While he shared a number of cases where he knew, a more recent case in public memory was when some labourers died while building Amanora mall which is perhaps one of largest malls in India. There were few accidents while constructing the mall. Apparently, the insurance money which should have gone to the migrant laborer was taken by somebody close to the developers who were building the mall. I have a friend in who lives in Jharkhand who is a labour officer. She has shared with me so many stories of how the labourers are exploited. Keep in mind she has been a labor officer appointed by the state and her salary is paid by the state. So she always has to maintain a balance of ensuring worker s rights and the interests of the state, private entities etc. which are usually in cahoots with the state and it is possible that lot of times the State wins over the worker s rights. Again, as a labour officer, she doesn t have that much power and when she was new to the work, she was often frustrated but as she remarked few months back, she has started taking it easy (routinized) as anyways it wasn t helping her in any good way. Also there have been plenty of cases of labor officers being murdered so its easier to understand why one tries to retain some sanity while doing their job.

The Indian response and the World Response The Indian response has been the lockdown and very limited testing. We seem to be following the pattern of UK and U.S. which had been slow to respond and slow to testing. In the past Kerala showed the way but this time even that is not enough. At the end of the day we need to test, test and test just as shared by the WHO chairman. India is trying to create its own cheap test kits with ICMR approval, for e.g. a firm from my own city Pune MyLab has been given approval. We will know how good or bad they are only after they have been field-tested. For ventilators we have asked Mahindra and Mahindra even though there are companies like Allied Medical and others who have exported to EU and others which the Govt. is still taking time to think through. This is similar to how in UK some companies who are with the Govt. but who have no experience in making ventilators are been given orders while those who have experience and were exporting to Germany and other countries are not been given orders. The playbook is errily similar. In India, we don t have the infrastructure for any new patients, period. Heck only a couple of states have done something proper for the anganwadi workers. In fact, last year there were massive strikes by anganwadi workers all over India but only NDTV showed a bit of it along with some of the news channels from South India. Most mainstream channels chose to ignore it. On the world stage, some of the other countries and how they have responded perhaps need sharing. For e.g. I didn t know that Cuba had so many doctors and the politics between it and Brazil. Or the interesting stats. shared by Andreas Backhaus which seems to show how distributed the issue (age-wise) is rather than just a few groups as has been told in Indian media. What was surprising for me is the 20-29 age group which has not been shared so much in the Indian media which is the bulk of our population. The HBR article also makes a few key points which I hope both the general public and policymakers both in India as well as elsewhere take note of. What is worrying though that people can be infected twice or more as seems to be from Singapore or China and elsewhere. I have read enough of Robin Cook and Michael Crichton books to be aware that viruses can do whatever. They will over time mutate, how things will happen then is anybody s guess. What I found interesting is the world economic forum article which hypothesis that it may be two viruses which got together as well as research paper from journal from poteome research which has recently been published. The biggest myth flying around is that summer will halt or kill the spread which even some of my friends have been victim of . While a part of me wants to believe them, a simple scientific fact has been viruses have probably been around us and evolved over time, just like we have. In fact, there have been cases of people dying due to common cold and other things. Viruses are so prevalent it s unbelivable. What is and was interesting to note is that bat-borne viruses as well as pangolin viruses had been theorized and shared by Chinese researchers going all the way back to 90 s . The problem is even if we killed all the bats in the world, some other virus will take its place for sure. One of the ideas I had, dunno if it s feasible or not that at least in places like Airports, we should have some sort of screenings and a labs working on virology. Of course, this will mean more expenses for flying passengers but for public health and safety maybe it would worth doing so. In any case, virologists should have a field day cataloging various viruses and would make it harder for viruses to spread as fast as this one has. The virus spread also showed a lack of leadership in most of our leaders who didn t react fast enough. While one hopes people do learn from this, I am afraid the whole thing is far from over. These are unprecedented times and hope that all are maintaining social distancing and going out only when needed.

25 March 2020

Raphaël Hertzog: Freexian s report about Debian Long Term Support, February 2020

A Debian LTS logo Like each month, here comes a report about the work of paid contributors to Debian LTS. Individual reports In February, 226 work hours have been dispatched among 14 paid contributors. Their reports are available: Evolution of the situation February began as rather calm month and the fact that more contributors have given back unused hours is an indicator of this calmness and also an indicator that contributing to LTS has become more of a routine now, which is good. In the second half of February Holger Levsen (from LTS) and Salvatore Bonaccorso (from the Debian Security Team) met at SnowCamp in Italy and discussed tensions and possible improvements from and for Debian LTS. The security tracker currently lists 25 packages with a known CVE and the dla-needed.txt file has 21 packages needing an update. Thanks to our sponsors New sponsors are in bold.

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22 March 2020

Sylvestre Ledru: Some clang rebuild results (8.0.1, 9.0.1 & 10rc2)

As part of the LLVM release cycle, I am continuing rebuilding the Debian archive with clang instead of gcc to evaluate potential regressions. Processed results are available on the website: https://clang.debian.net/status.php - Now includes some fancy graphs to show the evolution
Raw logs are published on github: https://github.com/opencollab/clang.debian.net/tree/master/logs Since my last blog post on the subject (August 2017), Clang is more and more present in the tech ecosystem. It is now the compiler used to build Firefox and Chrome upstream binaries on all the supported architectures/operating systems. More architectures are supported, it has a new linker (lld), a new hybrid IR (MLIR), a lot of checkers in clang-tidy, cross-language linking with Rust, etc.

Results
Now, about Debian results, we rebuilt using 8.0.1, 9.0.1 and 10.0rc2. Results are pretty similar to what we had with previous versions: between 4 to 5% of packages are failing when gcc is replaced by clang.
Some clang rebuild results (8.0.1, 9.0.1 & 10rc2)

Even if most of the software are still using gcc as compiler, we can see that clang has a positive effect on code quality. With many different kinds of errors and warnings found clang over the years, we noticed a steady decline of the number of errors. For example, the number of incorrect C/C++ main declarations has been decreasing years after years:
Some clang rebuild results (8.0.1, 9.0.1 & 10rc2)

Errors found
The biggest offender is still the qmake changes which doesn't allow the used workaround (replacing /usr/bin/gcc by /usr/bin/clang) - about 250 errors. Most of these packages would probably compile fine with clang. More on the Qt bug tracker. The workaround proposed in the bug isn't applicable for us as we use the dropped-in replacement of the
The second error is still some differences in symbol generation. Unlike gcc, it seems that clang doesn't generate some symbols (or adds some). As a bunch of Debian packages are checking the list of symbols in the library (for ABI management), the build fails on purpose. For example, with libcec, the symbol _ZN10P8PLATFORM14CConditionImplD1Ev@Base 3.1.0 isn't generated anymore. I am not expecting this to be a big deal: the generated libraries probably works most of the time. More on C++ symbol management in Debian.

Current status
As previously said in a blog post, I don't think there is a strong intensive to go away from gcc for most of the Linux distributions. The big reason for BSD was the license (even if the move to the Apache 2 license wasn't received positively by some of them).
While the LLVM/clang ecosystem clearly won the tooling battle, as a C/C++ compiler, gcc is still an excellent compiler which supports more architecture and more languages.
In term of new warnings and checks, as the clang community moved the efforts in clang-tidy (which requires more complex tooling), out of the box, gcc provides a better experience (as example, see the Firefox meta bug to build with -Werror with the default warnings using gcc 9, gcc 10 and clang trunk for example).

Next steps
I see some potential next steps to decrease the number of failure:
  • Workaround the Qt/Qmake issue
  • Fix the objective-c header include issues (echo "#include <objc/objc.h>" > foo.m && clang -c foo.m is currently failing)
  • Identify why clang generates more/less symbols that gcc in the library and try to fix that
  • Rebuild the archive with clang-7 - Seems that I have some data problem

Many thanks to Lucas Nussbaum for the rebuilds.

Sylvestre Ledru: Some clang rebuild results (8.0.1, 9.0.1 & 10rc2)

As part of the LLVM release cycle, I am continuing rebuilding the Debian archive with clang instead of gcc to evaluate potential regressions. Processed results are available on the website: https://clang.debian.net/status.php - Now includes some fancy graphs to show the evolution
Raw logs are published on github: https://github.com/opencollab/clang.debian.net/tree/master/logs Since my last blog post on the subject (August 2017), Clang is more and more present in the tech ecosystem. It is now the compiler used to build Firefox and Chrome upstream binaries on all the supported architectures/operating systems. More architectures are supported, it has a new linker (lld), a new hybrid IR (MLIR), a lot of checkers in clang-tidy, cross-language linking with Rust, etc.

Results
Now, about Debian results, we rebuilt using 8.0.1, 9.0.1 and 10.0rc2. Results are pretty similar to what we had with previous versions: between 4 to 5% of packages are failing when gcc is replaced by clang.
Some clang rebuild results (8.0.1, 9.0.1 &amp; 10rc2)

Even if most of the software are still using gcc as compiler, we can see that clang has a positive effect on code quality. With many different kinds of errors and warnings found clang over the years, we noticed a steady decline of the number of errors. For example, the number of incorrect C/C++ main declarations has been decreasing years after years:
Some clang rebuild results (8.0.1, 9.0.1 &amp; 10rc2)

Errors found
The biggest offender is still the qmake changes which doesn't allow the used workaround (replacing /usr/bin/gcc by /usr/bin/clang) - about 250 errors. Most of these packages would probably compile fine with clang. More on the Qt bug tracker. The workaround proposed in the bug isn't applicable for us as we use the dropped-in replacement of the compiler.
The second error is still some differences in symbol generation. Unlike gcc, it seems that clang doesn't generate some symbols (or adds some). As a bunch of Debian packages are checking the list of symbols in the library (for ABI management), the build fails on purpose. For example, with libcec, the symbol _ZN10P8PLATFORM14CConditionImplD1Ev@Base 3.1.0 isn't generated anymore. I am not expecting this to be a big deal: the generated libraries probably works most of the time. More on C++ symbol management in Debian.
I reported this bug upstream a while back: https://bugs.llvm.org/show_bug.cgi?id=30441

Current status
As previously said in a blog post, I don't think there is a strong intensive to go away from gcc for most of the Linux distributions. The big reason for BSD was the license (even if the move to the Apache 2 license wasn't received positively by some of them).
While the LLVM/clang ecosystem clearly won the tooling battle, as a C/C++ compiler, gcc is still an excellent compiler which supports more architecture and more languages.
In term of new warnings and checks, as the clang community moved the efforts in clang-tidy (which requires more complex tooling), out of the box, gcc provides a better experience (as example, see the Firefox meta bug to build with -Werror with the default warnings using gcc 9, gcc 10 and clang trunk for example).

Next steps
I see some potential next steps to decrease the number of failure:
  • Workaround the Qt/Qmake issue
  • Fix the objective-c header include issues (echo "#include <objc/objc.h>" > foo.m && clang -c foo.m is currently failing)
  • Identify why clang generates more/less symbols that gcc in the library and try to fix that
  • Rebuild the archive with clang-7 - Seems that I have some data problem

Many thanks to Lucas Nussbaum for the rebuilds.

10 March 2020

Enrico Zini: COVID-19 links

COVID-19 #CoronaVirus Infographic Datapack Information is Beautiful
chart covid19 health archive.org
COVID-19 Infographic Datapack, Regularly updated
European Centre for Disease Prevention and Control infographics
COVID-19 Italia - Monitoraggio situazione
Real-time tracking of pathogen evolution
Community sharing resources, verified information, and support initiatives, on COVID-19
Live world statistics on population, government and economics, society and media, environment, food, water, energy and health.
Your friends and colleagues are talking about something called Bayes s Theorem or Bayes s Rule, or something called Bayesian reasoning. They sound really enthusiastic about it, too, so you google and find a web page about Bayes s Theorem and... It s this equation. That s all. Just one equation. The page you found gives a definition of it, but it doesn t say what it is, or why it s useful, or why your friends would be interested in it. It looks like this random statistics thing. Why does a mathematical concept generate this strange enthusiasm in its students? What is the so-called Bayesian Revolution now sweeping through the sciences, which claims to subsume even the experimental method itself as a special case? What is the secret that the adherents of Bayes know? What is the light that they have seen? Soon you will know. Soon you will be one of us. While there are a few existing online explanations of Bayes s Theorem, my experience with trying to introduce people to Bayesian reasoning is that the existing online explanations are too abstract. Bayesian reasoning is very counterintuitive. People do not employ Bayesian reasoning intuitively, find it very difficult to learn Bayesian reasoning when tutored, and rapidly forget Bayesian methods once the tutoring is over. This holds equally true for novice students and highly trained professionals in a field. Bayesian reasoning is apparently one of those things which, like quantum mechanics or the Wason Selection Test, is inherently difficult for humans to grasp with our built-in mental faculties. Or so they claim. Here you will find an attempt to offer an intuitive explanation of Bayesian reasoning an excruciatingly gentle introduction that invokes all the human ways of grasping numbers, from natural frequencies to spatial visualization. The intent is to convey, not abstract rules for manipulating numbers, but what the numbers mean, and why the rules are what they are (and cannot possibly be anything else). When you are finished reading this, you will see Bayesian problems in your dreams.
Continuiamo a lavorare, studiare, socializzare grazie a Jitsi Meet

7 March 2020

Matthias Klumpp: Introducing the MetaInfo Creator

This year s FOSDEM conference was a lot of fun one of the things I always enjoy most about this particular conference (besides having some of the outstanding food you can get in Brussels and meeting with friends from the free software world) is the ability to meet a large range of new people who I wouldn t usually have interacted with, or getting people from different communities together who otherwise would not meet in person as each bigger project has their own conference (for example, the amount of VideoLAN people is much lower at GUADEC and Akademy compared to FOSDEM). It s also really neat to have GNOME and KDE developers within reach at the same place, as I care about both desktops a lot. An unexpected issue This blog post however is not about that. It s about what I learned when talking to people there about AppStream, and the outcome of that. Especially when talking to application authors but also to people who deal with larger software repositories, it became apparent that many app authors don t really want to deal with the extra effort of writing metadata at all. This was a bit of a surprise to me, as I thought that there would be a strong interest for application authors to make their apps look as good as possible in software catalogs. A bit less surprising was the fact that people apparently don t enjoy reading a large specification, reading a long-ish intro guide with lots of dos and don ts or basically reading any longer text at all before being able to create an AppStream MetaInfo/AppData file describing their software. Another common problem seems to be that people don t immediately know what a reverse-DNS ID is, the format AppStream uses for uniquely identifying each software component. So naturally, people either have to read about it again (bah, reading!  ) or make something up, which occasionally is wrong and not the actual component-ID their software component should have. The MetaInfo Creator It was actually suggested to me twice that what people really would like to have is a simple tool to put together a MetaInfo file for their software. Basically a simple form with a few questions which produces the final file. I always considered this a nice to have, but not essential feature, but now I was convinced that this actually has a priority attached to it. So, instead of jumping into my favourite editor and writing a bunch of C code to create this make MetaInfo file form as part of appstreamcli, this time I decided to try what the cool kids are doing and make a web application that runs in your browser and creates all metadata there. So, behold the MetaInfo Creator! If you click this link, you will end up at an Angular-based web application that will let you generate MetaInfo/AppData files for a few component-types simply by answering a set of questions. The intent was to make this tool as easy to use as possible for someone who basically doesn t know anything about AppStream at all. Therefore, the tool will: For the Meson feature, the tool simply can not generate a use this and be done script, as each Meson snippet needs to be adjusted for the individual project. So this option is disabled by default, but when enabled, a few simple Meson snippets will be produced which can be easily adjusted to the project they should be part of. The tool currently does not generate any release information for a MetaInfo file at all, This may be added in future. The initial goal was to have people create any MetaInfo file in the first place, having projects also ship release details would be the icing on the cake. I hope people find this project useful and use it to create better MetaInfo files, so distribution repositories and Flatpak repos look better in software centers. Also, since MetaInfo files can be used to create an inventory of software and to install missing stuff as-needed, having more of them will help to build smarter software managers, create smaller OS base installations and introspect what software bundles are made of easily. I welcome contributions to the MetaInfo Creator! You can find its source code on GitHub. This is my first web application ever, the first time I wrote TypeScript and the first time I used Angular, so I d bet a veteran developer more familiar with these tools will cringe at what I produced. So, scratch that itch and submit a PR!  Also, if you want to create a form for a new component type, please submit a patch as well. C developer s experience notes for Angular, TypeScript, NodeJS This section is just to ramble a bit about random things I found interesting as a developer who mostly works with C/C++ and Python and stepped into the web-application developer s world for the first time. For a project like this, I would usually have gone with my default way of developing something for the web: Creating a Flask-based application in Python. I really love Python and Flask, but of course using them would have meant that all processing would have had to be done on the server. One the one hand I could have used libappstream that way to create the XML, format it and validate it, but on the other hand I would have had to host the Python app on my own server, find a place at Purism/Debian/GNOME/KDE or get it housed at Freedesktop somehow (which would have taken a while to arrange) and I really wanted to have a permanent location for this application immediately. Additionally, I didn t want people to send the details of new unpublished software to my server. TypeScript I must say that I really like TypeScript as a language compared to JavaScript. It is not really revolutionary (I looked into Dart and other ways to compile $stuff to JavaScript first), but it removes just enough JavaScript weirdness to be pleasant to use. At the same time, since TS is a superset of JS, JavaScript code is valid TypeScript code, so you can integrate with existing JS code easily. Picking TS up took me much less than an hour, and most of its features you learn organically when working on a project. The optional type-safety is a blessing and actually helped me a few times to find an issue. It being so close to JS is both a strength and weakness: On the one hand you have all the JS oddities in the language (implicit type conversion is really weird sometimes) and have to basically refrain from using them or count on the linter to spot them, but on the other hand you can immediately use the massive amount of JavaScript code available on the web. Angular The Angular web framework took a few hours to pick up there are a lot of concepts to understand. But ultimately, it s manageable and pretty nice to use. When working at the system level, a lot of complexity is in understanding how the CPU is processing data, managing memory and using the low-level APIs the operating system provides. With the web application stuff, a lot of the complexity for me was in learning about all the moving parts the system is comprised of, what their names are, what they are, and what works with which. And that is not a flat learning curve at all. As C developer, you need to know how the computer works to be efficient, as web developer you need to know a bunch of different tools really well to be productive. One thing I am still a bit puzzled about is the amount of duplicated HTML templates my project has. I haven t found a way to reuse template blocks in multiple components with Angular, like I would with Jinja2. The documentation suggests this feature does not exist, but maybe I simply can t find it or there is a completely different way to achieve the same result. NPM Ecosystem The MetaInfo Creator application ultimately doesn t do much. But according to GitHub, it has 985 (!!!) dependencies in NPM/NodeJS. And that is the bare minimum! I only added one dependency myself to it. I feel really uneasy about this, as I prefer the Python approach of having a rich standard library instead of billions of small modules scattered across the web. If there is a bug in one of the standard library functions, I can submit a patch to Python where some core developer is there to review it. In NodeJS, I imagine fixing some module is much harder. That being said though, using npm is actually pretty nice there is a module available for most things, and adding a new dependency is easy. NPM will also manage all the details of your dependency chain, GitHub will warn about security issues in modules you depend on, etc. So, from a usability perspective, there isn t much to complain about (unlike with Python, where creating or using a module ends up as a fight the system event way too often and the question which random file do I need to create now to achieve what I want? always exists. Fortunately, Poetry made this a bit more pleasant for me recently). So, tl;dr for this section: The web application development excursion was actually a lot of fun, and I may make more of those in future, now that I learned more about how to write web applications. Ultimately though, I enjoy the lower-level software development and backend development a bit more. Summary Check out the MetaInfo Creator and its source code, if you want to create MetaInfo files for a GUI application, console application, addon or service component quickly.

3 March 2020

Ian Jackson: Let's Encrypt certificate revocation - panic now!

Let's Encrypt have rather quietly announced (sadly, requires discourse JS!) that they are going to revoke a very large number of certificates. These revocations will start "no earlier than" 00:00 UTC tonight (24:00 on the 3rd of March), a little over 9h from now. Affected websites etc. may stop working. I discovered this at about lunchtime UK time today; two of my certs were affected. xenproject.org and linuxfoundation.org are listed as affected and I am trying to get in touch with the hosting provider to get it fixed. One of the domains we in the Xen Project run ourselves, with the help of the contractors who do much of our sysadmin, is affected - and those contractors (who are very competent) didn't know until I told them. tl;dr: If you are responsible for any Let's Encrypt certificates, check it right away and maybe panic now!
edited 2020-03-03 15:35 to fix arithmetic error

comment count unavailable comments

2 March 2020

Petter Reinholdtsen: Nikita version 0.5 released - updated free software archive API server

Today, after many months of development, a new release of Nikita Noark 5 core project was finally announced on the project mailing list. The Nikita free software solution is an implementation of the Norwegian archive standard Noark 5 used by government offices in Norway. These were the changes in version 0.5 since version 0.4, see the email link above for links to a demo site: If free and open standardized archiving API sound interesting to you, please contact us on IRC (#nikita on irc.freenode.net) or email (nikita-noark mailing list). As usual, if you use Bitcoin and want to show your support of my activities, please send Bitcoin donations to my address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

18 November 2017

Matthieu Caneill: MiniDebconf in Toulouse

I attended the MiniDebconf in Toulouse, which was hosted in the larger Capitole du Libre, a free software event with talks, presentation of associations, and a keysigning party. I didn't expect the event to be that big, and I was very impressed by its organization. Cheers to all the volunteers, it has been an amazing week-end! Here's a sum-up of the talks I attended. Du logiciel libre la monnaie libre Speaker: lo s The first talk I attended was, translated to English, "from free software to free money". lo s compared the 4 freedoms of free software with money, and what properties money needs to exhibit in order to be considered free. He then introduced 1, a project of free (as in free speech!) money, started in the region around Toulouse. Contrary to some distributed ledgers such as Bitcoin, 1 isn't based on an hash-based proof-of-work, but rather around a web of trust of people certifying each other, hence limiting the energy consumption required by the network to function. YunoHost Speaker: Jimmy Monin I then attended a presentation of YunoHost. Being an happy user myself, it was very nice to discover the future expected features, and also meet two of the developers. YunoHost is a Debian-based project, aimed at providing all the tools necessary to self-host applications, including email, website, calendar, development tools, and dozens of other packages. Premiers pas dans l'univers de Debian Speaker: Nicolas Dandrimont For the first talk of the MiniDebConf, Nicolas Dandrimont introduced Debian, its philosophy, and how it works with regards to upstreams and downstreams. He gave many details on the teams, the infrastructure, and the internals of Debian. Trusting your computer and system Speaker: Jonas Smedegaard Jonas introduced some security concepts, and how they are abused and often meaningless (to quote his own words, "secure is bullshit"). He described a few projects which lean towards a more secure and open hardware, for both phones and laptops. Automatiser la gestion de configuration de Debian avec Ansible Speaker: J r my Lecour J r my, from Evolix, introduced Ansible, and how they use it to manage hundreds of Debian servers. Ansible is a very powerful tool, and a huge ecosystem, in many ways similar to Puppet or Chef, except it is agent-less, using only ssh connections to communicate with remote machines. Very nice to compare their use of Ansible with mine, since that's the software I use at work for deploying experiments. Making Debian for everybody Speaker: Samuel Thibault Samuel gave a talk about accessibility, and the general availability of the tools in today's operating systems, including Debian. The lesson to take home is that we often don't do enough in this domain, particularly when considering some issues people might have that we don't always think about. Accessibility on computers (and elsewhere) should be the default, and never require complex setups. Retour d'exp rience : mise jour de milliers de terminaux Debian Speaker: Cyril Brulebois Cyril described a problem he was hired for, an update of thousands of Debian servers from wheezy to jessie, which he discovered afterwards was worse than initially thought, since the machines were running the out-of-date squeeze. Since they were not always administered with the best sysadmin practices, they were all exhibiting different configurations and different packages lists, which raised many issues and gave him interesting challenges. They were solved using Ansible, which also had the effect of standardizing their system administration practices. Retour d'exp rience : utilisation de Debian chez Evolix Speaker: Gr gory Colpart Gr gory described Evolix, a company which manages servers for their clients, and how they were inspired by Debian, for both their internal tools and their practices. It is very interesting to see that some of the Debian values can be easily exported for a more open and collaborative business. Lightning talks To close the conference, two lightning talks were presented, describing the switch from Windows XP to Debian in an ecologic association near Toulouse; and how snapshot.debian.org can be used with bisections to find the source of some regressions. Conclusion A big thank you to all the organizers and the associations who contributed to make this event a success. Cheers!

17 November 2017

Rapha&#235;l Hertzog: Freexian s report about Debian Long Term Support, October 2017

A Debian LTS logoLike each month, here comes a report about the work of paid contributors to Debian LTS. Individual reports In October, about 197 work hours have been dispatched among 13 paid contributors. Their reports are available: Evolution of the situation The number of sponsored hours increased slightly to 183 hours per month. With the increasing number of security issues to deal with, and with the number of open issues not really going down, I decided to bump the funding target to what amounts to 1.5 full-time position. The security tracker currently lists 50 packages with a known CVE and the dla-needed.txt file 36 (we re a bit behind in CVE triaging apparently). Thanks to our sponsors New sponsors are in bold.

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12 November 2017

Ben Armstrong: The Joy of Cat Intelligence

As a cat owner, being surprised by cat intelligence delights me. They re not exactly smart like a human, but they are smart in cattish ways. The more I watch them and try to sort out what they re thinking, the more it pleases me to discover they can solve problems and adapt in recognizably intelligent ways, sometimes unique to each individual cat. Each time that happens, it evokes in me affectionate wonder. Today, I had one of those joyful moments. First, you need to understand that some months ago, I thought I had my male cat all figured out with respect to mealtimes. I had been cleaning up after my oafish boy who made a watery mess on the floor from his mother s bowl each morning. I was slightly annoyed, but was mostly curious, and had a hunch. A quick search of the web confirmed it: my cat was left-handed. Not only that, but I learned this is typical for males, whereas females tend to be right-handed. Right away, I knew what I had to do: I adjusted the position of their water bowls relative to their food, swapping them from right to left; the messy morning feedings ceased. I congratulated myself for my cleverness. You see, after the swap, as he hooked the kibbles with his left paw out of the right-hand bowl, they would land immediately on the floor where he could give them chase. The swap caused the messes to cease because before, his left-handed scoops would land the kibbles in the water to the right; he would then have to scoop the kibble out onto the floor, sprinkling water everywhere! Furthermore, the sodden kibble tended to not skitter so much, decreasing his fun. Or so I thought. Clearly, I reasoned, having sated himself on the entire contents of his own bowl, he turned to pilfering his mother s leftovers for some exciting kittenish play. I had evidence to back it up, too: he and his mother both seem to enjoy this game, a regular fixture of their mealtime routines. She, too, is adept at hooking out the kibbles, though mysteriously, without making a mess in her water, whichever way the bowls are oriented. I chalked this up to his general clumsiness of movement vs. her daintiness and precision, something I had observed many times before. Come to think of it, lately, I ve been seeing more mess around his mother s bowl again. Hmm. I don t know why I didn t stop to consider why And then my cat surprised me again. This morning, with Shadow behind my back as I sat at my computer, finishing up his morning meal at his mother s bowl, I thought I heard something odd. Or rather, I didn t hear something. The familiar skitter-skitter sound of kibbles evading capture was missing. So I turned and looked. My dear, devious boy had squished his overgrown body behind his mother s bowls, nudging them ever so slightly askew to fit the small space. Now the bowl orientation was swapped back again. Stunned, I watched him carefully flip out a kibble with his left paw. Plop! Into the water on the right. Concentrating, he fished for it. A miss! He casually licked the water from his paw. Another try. Swoop! Plop, onto the floor. No chase now, just satisfied munching of his somewhat mushy kibble. And then it dawned on me that I had got it somewhat wrong. Yes, he enjoyed Chase the Kibble, like his mom, but I never recognized he had been indulging in a favourite pastime, peculiarly his own I had judged his mealtime messes as accidents, a very human way of thinking about my problem. Little did I know, it was deliberate! His private game was Bobbing for Kibbles. I don t know if it s the altered texture, or dabbling in the bowl, but whatever the reason, due to my meddling, he had been deprived of this pleasure. No worries, a thwarted cat will find a way. And that is the joy of cat intelligence.

29 October 2017

Russ Allbery: Review: Why We Sleep

Review: Why We Sleep, by Matthew Walker
Publisher: Scribner
Copyright: October 2017
ISBN: 1-5011-4433-2
Format: Kindle
Pages: 341
The world is full of theories, and corresponding books, about things that will make you healthier or prevent disease. Nearly all of them are scams, either intentional or created through the placebo effect and the human tendency to see patterns that don't exist. The rare ones that aren't have a certain pattern: they're grounded in our best understanding of biology, align with what our body wants to do anyway, have been thoroughly studied using proper testing methodology, and don't make money for powerful corporations. I'm fairly sure this is one of those rare ones that isn't a scam. And, if so, it's rather important and worth your attention. Matthew Walker is a professor of neuroscience and biology at the University of California at Berkeley, where he's the founder of the Center for Human Sleep Science. He's not a doctor; he started medical training, but (as he says in the book) found himself more attracted to questions than answers. He's a professional academic researcher who has been studying sleep for decades. This book is a combination of summary of the current state of knowledge of academic sleep research and a plea: get more sleep, because we're literally killing ourselves with the lack of it. Walker opens the book with a discussion of the mechanisms of sleep: how we biologically fall asleep and why, how this has changed over time, and how it changes with age. Along with that, he defines sleep: the REM and NREM sleep cycle that you may have already heard of, how it manifests itself in most people, and where dreams fit in. The second part then discusses what happens when you sleep, with a focus on what goes wrong when you don't. (Spoiler: A lot. Study after study, all cited and footnoted, has found connections between sleep and just about every aspect of mental and physical health.) The third part does the same for dreams, fitting them into the picture along with a scientific discussion of just what's going on during dreams. The fourth and final part tackles the problem: why don't we get enough sleep, and what can we do about it? I will warn in advance that this book will make you paranoid about your sleeping patterns. Walker has the missionary zeal of an academic who has sunk his teeth into something really important that society needs to take into account and will try to drown you in data, analysis, analogies, and sheer earnestness until you will believe him. He wants you to get at least seven, and preferably eight, hours of sleep a night. Every night, with as little variation as you can manage. Everyone, even if you think you're someone who doesn't need as much sleep (you're probably not). There's a ton of science here, a great popularization of a whole field of research, but this is also a book that's trying to get you to do something. Normally, that sort of book raises my shields. I'm not much of a believer in any book of the general genre of "most people are doing this basic part of life wrong, and should do it my way instead." But the hallmarks of good science are here: very widespread medical consensus, no corporate interest or obvious path to profit, and lots of studies (footnoted here, with some discussions of methodology although not the statistical details, which will require looking up the underlying studies and careful caveats where studies indicate correlation but may not find causes). And Walker makes the very telling point early in the book that nearly every form of life on the planet sleeps in one way or another (defined as a daily recurring period of time during which it doesn't respond to outside stimulus), which is a strong indicator of universal necessity. Given the vulnerability and loss of useful hours that come with sleep, one would expect some species to find an evolutionary path away from it if it were dispensable. But except for extremely short-lived species, we've never found a living creature that didn't sleep. Walker's argument for duration is also backed up by repeated studies on human capability before and after various quantities of sleep, and on studies of the sleep phases in various parts of the night. Study after study used six hours as the cutoff point and showed substantial deterioration in physical and mental capabilities even after only one night of short sleeping. (Reducing sleep to four hours is nearly catastrophic.) And, more worrisomely, that degradation is still measurable after "catching up" on sleep on subsequent nights. Sleeping in on weekends doesn't appear to fully compensate for the damage done by short-sleeping during the week. When Walker gets into the biological reasons for sleep, one starts to understand why it's so important. I think the part I found the most fascinating was the detailed analysis of what the brain is doing while you sleep. It's not inactive at all, even outside of REM sleep. Walker and other sleep researchers have done intriguing experiments showing how different parts of the sleep cycle transfer memories from short to long term storage, transfer physical skills into subconscious parts of the brain, discard short term memories that the conscious brain has tagged as being unwanted, and free up space for new knowledge acquisition. REM sleep appears to attempt to connect otherwise unrelated memories and bits of knowledge, inverting how association normally works in the brain, thus providing some concrete explanation for sleep's role in creativity. And (this research is fairly new), deep NREM sleep causes temporary physical changes in the brain that appear to be involved in flushing metabolic waste products away, including the plaque involved in Alzheimer's. The last part of the book is probably the most concretely useful: what can one practically do to get more sleep? There is quite a lot that's proven effective, but Walker starts with something else: sleeping pills. Here, you can almost see the lines drawn by a lawyer around what Walker should say. He stresses that he's not a medical doctor while laying out study after study that all point in the same direction: sleeping pills are a highly dangerous medical fraud that will shorten your lifespan for negligible benefit in helping you fall asleep, while limiting your brain's ability to enter true sleep. They're sedation, sedation is not sleep, and the four billion dollar sleeping pill market is literally making everything worse. The good news is there is an effective treatment for insomnia that works for many people; the better news is that it's completely free (although Walker does suggest some degree of medical supervision for serious insomnia so that some parts of it can be tailored to you). He walks through CBT-I (cognitive behavior therapy for insomnia), which is now the medically recommended primary treatment for insomnia, and takes apart the pieces to show how they line up with the results of sleep research studies. Alongside that are recommendations for improving sleep for people who don't have clinical insomnia but who aren't regularly getting the recommended amount of sleep. There are a lot of interesting bits here (and he of course talks about blue LED light and its relationship to melatonin cycles), but I think the most interesting for me was that you have to lower your core body temperature by a couple of degrees (Fahrenheit) to enter sleep. The temperature of your sleeping environment is therefore doubly important: temperature changes are one of the signals your body uses to regulate circadian rhythms (cold being a signal of night), and a colder sleeping area helps you lower your core body temperature so that you can fall asleep. (The average person does best with a sleeping room temperature of 65F, 18C.) There's even more in here: I haven't touched on Walker's attack on the US tendency to push high school start times earlier and earlier in the day (particularly devastating for teenagers, whose circadian rhythms move two hours later in the day than adults before slowly returning to an adult cycle). Or the serious problems of waking to an alarm clock, and the important benefits of the sleep that comes at the end of a full night's cycle. Or the benefits of dreams in dealing with trauma and some theories for how PTSD may interfere with that process. Or the effect of sleep on the immune system. Walker's writing style throughout Why We Sleep is engaging and clear, although sometimes too earnest. He really wants the reader to believe him and to get more sleep, and sometimes that leaks around the edges. One can also see the effort he's putting into not reading too much into research studies, but if there's a flaw in the science here, it's that I think Walker takes a few tentative conclusions a bit too far. (I'm sure these studies have the standard research problem of being frequently done on readily-available grad students rather than representative samples of the population, although the universality of sleep works in science's favor here.) Some of the recitations of research studies can get rather dry, and I once again discovered how boring I find most discussion of dreams, but for a first book written by an academic, this is quite readable. This is one of those books that I want everyone to read mostly so that they can get the information in it, not as much for the enjoyment of reading the book itself. I've been paying closer attention to my own sleep patterns for the last few years, and my personal experience lines up neatly with the book in both techniques to get better sleep and the benefits of that sleep. I'd already reached the point where I was cringing when people talk about regularly going on four or five hours of sleep; this is an entire book full of researched reasons to not do that. (Walker points out that both Reagan and Thatcher, who bragged about not requiring much sleep, developed Alzheimer's, and calls out Trump for making the same brag.) The whole book may not be of interest to everyone, but I think everyone should at least understand why the World Heath Organization recommends eight hours a night and labels shift work a probable carcinogen. And, as Walker points out, we should be teaching some of this stuff in school health classes alongside nutrition and sex education. Alas, Walker can't provide much advice on what I think is the largest robber of sleep: the constant time pressure of modern life, in which an uninterrupted nine hour sleep opportunity feels like an unaffordable luxury. Rating: 9 out of 10

20 October 2017

Rapha&#235;l Hertzog: Freexian s report about Debian Long Term Support, September 2017

A Debian LTS logoLike each month, here comes a report about the work of paid contributors to Debian LTS. Individual reports In August, about 170 work hours have been dispatched among 13 paid contributors. Their reports are available: Evolution of the situation The number of sponsored hours is the same as last month. But we have a new sponsor in the pipe. The security tracker currently lists 52 packages with a known CVE and the dla-needed.txt file 49. The number of packages with open issues decreased slightly compared to last month but we re not yet back to the usual situation. Thanks to our sponsors New sponsors are in bold.

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17 October 2017

Antoine Beaupr : A comparison of cryptographic keycards

An earlier article showed that private key storage is an important problem to solve in any cryptographic system and established keycards as a good way to store private key material offline. But which keycard should we use? This article examines the form factor, openness, and performance of four keycards to try to help readers choose the one that will fit their needs. I have personally been using a YubiKey NEO, since a 2015 announcement on GitHub promoting two-factor authentication. I was also able to hook up my SSH authentication key into the YubiKey's 2048 bit RSA slot. It seemed natural to move the other subkeys onto the keycard, provided that performance was sufficient. The mail client that I use, (Notmuch), blocks when decrypting messages, which could be a serious problems on large email threads from encrypted mailing lists. So I built a test harness and got access to some more keycards: I bought a FST-01 from its creator, Yutaka Niibe, at the last DebConf and Nitrokey donated a Nitrokey Pro. I also bought a YubiKey 4 when I got the NEO. There are of course other keycards out there, but those are the ones I could get my hands on. You'll notice none of those keycards have a physical keypad to enter passwords, so they are all vulnerable to keyloggers that could extract the key's PIN. Keep in mind, however, that even with the PIN, an attacker could only ask the keycard to decrypt or sign material but not extract the key that is protected by the card's firmware.

Form factor The Nitrokey Pro, YubiKey NEO (worn out), YubiKey 4, and FST-01 The four keycards have similar form factors: they all connect to a standard USB port, although both YubiKey keycards have a capacitive button by which the user triggers two-factor authentication and the YubiKey 4 can also require a button press to confirm private key use. The YubiKeys feel sturdier than the other two. The NEO has withstood two years of punishment in my pockets along with the rest of my "real" keyring and there is only minimal wear on the keycard in the picture. It's also thinner so it fits well on the keyring. The FST-01 stands out from the other two with its minimal design. Out of the box, the FST-01 comes without a case, so the circuitry is exposed. This is deliberate: one of its goals is to be as transparent as possible, both in terms of software and hardware design and you definitely get that feeling at the physical level. Unfortunately, that does mean it feels more brittle than other models: I wouldn't carry it in my pocket all the time, although there is a case that may protect the key a little better, but it does not provide an easy way to hook it into a keyring. In the group picture above, the FST-01 is the pink plastic thing, which is a rubbery casing I received along with the device when I got it. Notice how the USB connectors of the YubiKeys differ from the other two: while the FST-01 and the Nitrokey have standard USB connectors, the YubiKey has only a "half-connector", which is what makes it thinner than the other two. The "Nano" form factor takes this even further and almost disappears in the USB port. Unfortunately, this arrangement means the YubiKey NEO often comes loose and falls out of the USB port, especially when connected to a laptop. On my workstation, however, it usually stays put even with my whole keyring hanging off of it. I suspect this adds more strain to the host's USB port but that's a tradeoff I've lived with without any noticeable wear so far. Finally, the NEO has this peculiar feature of supporting NFC for certain operations, as LWN previously covered, but I haven't used that feature yet. The Nitrokey Pro looks like a normal USB key, in contrast with the other two devices. It does feel a little brittle when compared with the YubiKey, although only time will tell how much of a beating it can take. It has a small ring in the case so it is possible to carry it directly on your keyring, but I would be worried the cap would come off eventually. Nitrokey devices are also two times thicker than the Yubico models which makes them less convenient to carry around on keyrings.

Open and closed designs The FST-01 is as open as hardware comes, down to the PCB design available as KiCad files in this Git repository. The software running on the card is the Gnuk firmware that implements the OpenPGP card protocol, but you can also get it with firmware implementing a true random number generator (TRNG) called NeuG (pronounced "noisy"); the device is programmable through a standard Serial Wire Debug (SWD) port. The Nitrokey Start model also runs the Gnuk firmware. However, the Nitrokey website announces only ECC and RSA 2048-bit support for the Start, while the FST-01 also supports RSA-4096. Nitrokey's founder Jan Suhr, in a private email, explained that this is because "Gnuk doesn't support RSA-3072 or larger at a reasonable speed". Its devices (the Pro, Start, and HSM models) use a similar chip to the FST-01: the STM32F103 microcontroller. Nitrokey Pro with STM32F103TBU6 MCU Nitrokey also publishes its hardware designs, on GitHub, which shows the Pro is basically a fork of the FST-01, according to the ChangeLog. I opened the case to confirm it was using the STM MCU, something I should warn you against; I broke one of the pins holding it together when opening it so now it's even more fragile. But at least, I was able to confirm it was built using the STM32F103TBU6 MCU, like the FST-01. Nitrokey back side But this is where the comparison ends: on the back side, we find a SIM card reader that holds the OpenPGP card that, in turn, holds the private key material and does the cryptographic operations. So, in effect, the Nitrokey Pro is really a evolution of the original OpenPGP card readers. Nitrokey confirmed the OpenPGP card featured in the Pro is the same as the one shipped by the Free Software Foundation Europe (FSFE): the BasicCard built by ZeitControl. Those cards, however, are covered by NDAs and the firmware is only partially open source. This makes the Nitrokey Pro less open than the FST-01, but that's an inevitable tradeoff when choosing a design based on the OpenPGP cards, which Suhr described to me as "pretty proprietary". There are other keycards out there, however, for example the SLJ52GDL150-150k smartcard suggested by Debian developer Yves-Alexis Perez, which he prefers as it is certified by French and German authorities. In that blog post, he also said he was experimenting with the GPL-licensed OpenPGP applet implemented by the French ANSSI. But the YubiKey devices are even further away in the closed-design direction. Both the hardware designs and firmware are proprietary. The YubiKey NEO, for example, cannot be upgraded at all, even though it is based on an open firmware. According to Yubico's FAQ, this is due to "best security practices": "There is a 'no upgrade' policy for our devices since nothing, including malware, can write to the firmware." I find this decision questionable in a context where security updates are often more important than trying to design a bulletproof design, which may simply be impossible. And the YubiKey NEO did suffer from critical security issue that allowed attackers to bypass the PIN protection on the card, which raises the question of the actual protection of the private key material on those cards. According to Niibe, "some OpenPGP cards store the private key unencrypted. It is a common attitude for many smartcard implementations", which was confirmed by Suhr: "the private key is protected by hardware mechanisms which prevent its extraction and misuse". He is referring to the use of tamper resistance. After that security issue, there was no other option for YubiKey NEO users than to get a new keycard (for free, thankfully) from Yubico, which also meant discarding the private key material on the key. For OpenPGP keys, this may mean having to bootstrap the web of trust from scratch if the keycard was responsible for the main certification key. But at least the NEO is running free software based on the OpenPGP card applet and the source is still available on GitHub. The YubiKey 4, on the other hand, is now closed source, which was controversial when the new model was announced last year. It led the main Linux Foundation system administrator, Konstantin Ryabitsev, to withdraw his endorsement of Yubico products. In response, Yubico argued that this approach was essential to the security of its devices, which are now based on "a secure chip, which has built-in countermeasures to mitigate a long list of attacks". In particular, it claims that:
A commercial-grade AVR or ARM controller is unfit to be used in a security product. In most cases, these controllers are easy to attack, from breaking in via a debug/JTAG/TAP port to probing memory contents. Various forms of fault injection and side-channel analysis are possible, sometimes allowing for a complete key recovery in a shockingly short period of time.
While I understand those concerns, they eventually come down to the trust you have in an organization. Not only do we have to trust Yubico, but also hardware manufacturers and designs they have chosen. Every step in the hidden supply chain is then trusted to make correct technical decisions and not introduce any backdoors. History, unfortunately, is not on Yubico's side: Snowden revealed the example of RSA security accepting what renowned cryptographer Bruce Schneier described as a "bribe" from the NSA to weaken its ECC implementation, by using the presumably backdoored Dual_EC_DRBG algorithm. What makes Yubico or its suppliers so different from RSA Security? Remember that RSA Security used to be an adamant opponent to the degradation of encryption standards, campaigning against the Clipper chip in the first crypto wars. Even if we trust the Yubico supply chain, how can we trust a closed design using what basically amounts to security through obscurity? Publicly auditable designs are an important tradition in cryptography, and that principle shouldn't stop when software is frozen into silicon. In fact, a critical vulnerability called ROCA disclosed recently affects closed "smartcards" like the YubiKey 4 and allows full private key recovery from the public key if the key was generated on a vulnerable keycard. When speaking with Ars Technica, the researchers outlined the importance of open designs and questioned the reliability of certification:
Our work highlights the dangers of keeping the design secret and the implementation closed-source, even if both are thoroughly analyzed and certified by experts. The lack of public information causes a delay in the discovery of flaws (and hinders the process of checking for them), thereby increasing the number of already deployed and affected devices at the time of detection.
This issue with open hardware designs seems to be recurring topic of conversation on the Gnuk mailing list. For example, there was a discussion in September 2017 regarding possible hardware vulnerabilities in the STM MCU that would allow extraction of encrypted key material from the key. Niibe referred to a talk presented at the WOOT 17 workshop, where Johannes Obermaier and Stefan Tatschner, from the Fraunhofer Institute, demonstrated attacks against the STMF0 family MCUs. It is still unclear if those attacks also apply to the older STMF1 design used in the FST-01, however. Furthermore, extracted private key material is still protected by user passphrase, but the Gnuk uses a weak key derivation function, so brute-forcing attacks may be possible. Fortunately, there is work in progress to make GnuPG hash the passphrase before sending it to the keycard, which should make such attacks harder if not completely pointless. When asked about the Yubico claims in a private email, Niibe did recognize that "it is true that there are more weak points in general purpose implementations than special implementations". During the last DebConf in Montreal, Niibe explained:
If you don't trust me, you should not buy from me. Source code availability is only a single factor: someone can maliciously replace the firmware to enable advanced attacks.
Niibe recommends to "build the firmware yourself", also saying the design of the FST-01 uses normal hardware that "everyone can replicate". Those advantages are hard to deny for a cryptographic system: using more generic components makes it harder for hostile parties to mount targeted attacks. A counter-argument here is that it can be difficult for a regular user to audit such designs, let alone physically build the device from scratch but, in a mailing list discussion, Debian developer Ian Jackson explained that:
You don't need to be able to validate it personally. The thing spooks most hate is discovery. Backdooring supposedly-free hardware is harder (more costly) because it comes with greater risk of discovery. To put it concretely: if they backdoor all of them, someone (not necessarily you) might notice. (Backdooring only yours involves messing with the shipping arrangements and so on, and supposes that you specifically are of interest.)
Since that, as far as we know, the STM microcontrollers are not backdoored, I would tend to favor those devices instead of proprietary ones, as such a backdoor would be more easily detectable than in a closed design. Even though physical attacks may be possible against those microcontrollers, in the end, if an attacker has physical access to a keycard, I consider the key compromised, even if it has the best chip on the market. In our email exchange, Niibe argued that "when a token is lost, it is better to revoke keys, even if the token is considered secure enough". So like any other device, physical compromise of tokens may mean compromise of the key and should trigger key-revocation procedures.

Algorithms and performance To establish reliable performance results, I wrote a benchmark program naively called crypto-bench that could produce comparable results between the different keys. The program takes each algorithm/keycard combination and runs 1000 decryptions of a 16-byte file (one AES-128 block) using GnuPG, after priming it to get the password cached. I assume the overhead of GnuPG calls to be negligible, as it should be the same across all tokens, so comparisons are possible. AES encryption is constant across all tests as it is always performed on the host and fast enough to be irrelevant in the tests. I used the following:
  • Intel(R) Core(TM) i3-6100U CPU @ 2.30GHz running Debian 9 ("stretch"/stable amd64), using GnuPG 2.1.18-6 (from the stable Debian package)
  • Nitrokey Pro 0.8 (latest firmware)
  • FST-01, running Gnuk version 1.2.5 (latest firmware)
  • YubiKey NEO OpenPGP applet 1.0.10 (not upgradable)
  • YubiKey 4 4.2.6 (not upgradable)
I ran crypto-bench for each keycard, which resulted in the following:
Algorithm Device Mean time (s)
ECDH-Curve25519 CPU 0.036
FST-01 0.135
RSA-2048 CPU 0.016
YubiKey-4 0.162
Nitrokey-Pro 0.610
YubiKey-NEO 0.736
FST-01 1.265
RSA-4096 CPU 0.043
YubiKey-4 0.875
Nitrokey-Pro 3.150
FST-01 8.218
Decryption graph There we see the performance of the four keycards I tested, compared with the same operations done without a keycard: the "CPU" device. That provides the baseline time of GnuPG decrypting the file. The first obvious observation is that using a keycard is slower: in the best scenario (FST-01 + ECC) we see a four-fold slowdown, but in the worst case (also FST-01, but RSA-4096), we see a catastrophic 200-fold slowdown. When I presented the results on the Gnuk mailing list, GnuPG developer Werner Koch confirmed those "numbers are as expected":
With a crypto chip RSA is much faster. By design the Gnuk can't be as fast - it is just a simple MCU. However, using Curve25519 Gnuk is really fast.
And yes, the FST-01 is really fast at doing ECC, but it's also the only keycard that handles ECC in my tests; the Nitrokey Start and Nitrokey HSM should support it as well, but I haven't been able to test those devices. Also note that the YubiKey NEO doesn't support RSA-4096 at all, so we can only compare RSA-2048 across keycards. We should note, however, that ECC is slower than RSA on the CPU, which suggests the Gnuk ECC implementation used by the FST-01 is exceptionally fast. In discussions about improving the performance of the FST-01, Niibe estimated the user tolerance threshold to be "2 seconds decryption time". In a new design using the STM32L432 microcontroller, Aurelien Jarno was able to bring the numbers for RSA-2048 decryption from 1.27s down to 0.65s, and for RSA-4096, from 8.22s down to 3.87s seconds. RSA-4096 is still beyond the two-second threshold, but at least it brings the FST-01 close to the YubiKey NEO and Nitrokey Pro performance levels. We should also underline the superior performance of the YubiKey 4: whatever that thing is doing, it's doing it faster than anyone else. It does RSA-4096 faster than the FST-01 does RSA-2048, and almost as fast as the Nitrokey Pro does RSA-2048. We should also note that the Nitrokey Pro also fails to cross the two-second threshold for RSA-4096 decryption. For me, the FST-01's stellar performance with ECC outshines the other devices. Maybe it says more about the efficiency of the algorithm than the FST-01 or Gnuk's design, but it's definitely an interesting avenue for people who want to deploy those modern algorithms. So, in terms of performance, it is clear that both the YubiKey 4 and the FST-01 take the prize in their own areas (RSA and ECC, respectively).

Conclusion In the above presentation, I have evaluated four cryptographic keycards for use with various OpenPGP operations. What the results show is that the only efficient way of storing a 4096-bit encryption key on a keycard would be to use the YubiKey 4. Unfortunately, I do not feel we should put our trust in such closed designs so I would argue you should either stick with 2048-bit encryption subkeys or keep the keys on disk. Considering that losing such a key would be catastrophic, this might be a good approach anyway. You should also consider switching to ECC encryption: even though it may not be supported everywhere, GnuPG supports having multiple encryption subkeys on a keyring: if one algorithm is unsupported (e.g. GnuPG 1.4 doesn't support ECC), it will fall back to a supported algorithm (e.g. RSA). Do not forget your previously encrypted material doesn't magically re-encrypt itself using your new encryption subkey, however. For authentication and signing keys, speed is not such an issue, so I would warmly recommend either the Nitrokey Pro or Start, or the FST-01, depending on whether you want to start experimenting with ECC algorithms. Availability also seems to be an issue for the FST-01. While you can generally get the device when you meet Niibe in person for a few bucks (I bought mine for around \$30 Canadian), the Seeed online shop says the device is out of stock at the time of this writing, even though Jonathan McDowell said that may be inaccurate in a debian-project discussion. Nevertheless, this issue may make the Nitrokey devices more attractive. When deciding on using the Pro or Start, Suhr offered the following advice:
In practice smart card security has been proven to work well (at least if you use a decent smart card). Therefore the Nitrokey Pro should be used for high security cases. If you don't trust the smart card or if Nitrokey Start is just sufficient for you, you can choose that one. This is why we offer both models.
So far, I have created a signing subkey and moved that and my authentication key to the YubiKey NEO, because it's a device I physically trust to keep itself together in my pockets and I was already using it. It has served me well so far, especially with its extra features like U2F and HOTP support, which I use frequently. Those features are also available on the Nitrokey Pro, so that may be an alternative if I lose the YubiKey. I will probably move my main certification key to the FST-01 and a LUKS-encrypted USB disk, to keep that certification key offline but backed up on two different devices. As for the encryption key, I'll wait for keycard performance to improve, or simply switch my whole keyring to ECC and use the FST-01 or Nitrokey Start for that purpose.
[The author would like to thank Nitrokey for providing hardware for testing.] This article first appeared in the Linux Weekly News.

9 October 2017

Antonio Terceiro: pristine-tar updates

Introduction pristine-tar is a tool that is present in the workflow of a lot of Debian people. I adopted it last year after it has been orphaned by its creator Joey Hess. A little after that Tomasz Buchert joined me and we are now a functional two-person team. pristine-tar goals are to import the content of a pristine upstream tarball into a VCS repository, and being able to later reconstruct that exact same tarball, bit by bit, based on the contents in the VCS, so we don t have to store a full copy of that tarball. This is done by storing a binary delta files which can be used to reconstruct the original tarball from a tarball produced with the contents of the VCS. Ultimately, we want to make sure that the tarball that is uploaded to Debian is exactly the same as the one that has been downloaded from upstream, without having to keep a full copy of it around if all of its contents is already extracted in the VCS anyway. The current state of the art, and perspectives for the future pristine-tar solves a wicked problem, because our ability to reconstruct the original tarball is affected by changes in the behavior of tar and of all of the compression tools (gzip, bzip2, xz) and by what exact options were used when creating the original tarballs. Because of this, pristine-tar currently has a few embedded copies of old versions of compressors to be able to reconstruct tarballs produced by them, and also rely on a ever-evolving patch to tar that is been carried in Debian for a while. So basically keeping pristine-tar working is a game of Whac-A-Mole. Joey provided a good summary of the situation when he orphaned pristine-tar. Going forward, we may need to rely on other ways of ensuring integrity of upstream source code. That could take the form of signed git tags, signed uncompressed tarballs (so that the compression doesn t matter), or maybe even a different system for storing actual tarballs. Debian bug #871806 contains an interesting discussion on this topic. Recent improvements Even if keeping pristine-tar useful in the long term will be hard, too much of Debian work currently relies on it, so we can t just abandon it. Instead, we keep figuring out ways to improve. And I have good news: pristine-tar has recently received updates that improve the situation quite a bit. In order to be able to understand how better we are getting at it, I created a "visualization of the regression test suite results. With the help of data from there, let s look at the improvements made since pristine-tar 1.38, which was the version included in stretch. pristine-tar 1.39: xdelta3 by default. This was the first release made after the stretch release, and made xdelta3 the default delta generator for newly-imported tarballs. Existing tarballs with deltas produced by xdelta are still supported, this only affects new imports. The support for having multiple delta generator was written by Tomasz, and was already there since 1.35, but we decided to only flip the switch after using xdelta3 was supported in a stable release. pristine-tar 1.40: improved compression heuristics pristine-tar uses a few heuristics to produce the smaller delta possible, and this includes trying different compression options. In the release Tomasz included a contribution by Lennart Sorensen to also try the --gnu, which gretly improved the support for rsyncable gzip compressed files. We can see an example of the type of improvement we got in the regression test suite data for delta sizes for faad2_2.6.1.orig.tar.gz: In 1.40, the delta produced from the test tarball faad2_2.6.1.orig.tar.gz went down from 800KB, almost the same size of tarball itself, to 6.8KB pristine-tar 1.41: support for signatures This release saw the addition of support for storage and retrieval of upstream signatures, contributed by Chris Lamb. pristine-tar 1.42: optionally recompressing tarballs I had this idea and wanted to try it out: most of our problems reproducing tarballs come from tarballs produced with old compressors, or from changes in compressor behavior, or from uncommon compression options being used. What if we could just recompress the tarballs before importing then? Yes, this kind of breaks the pristine bit of the whole business, but on the other hand, 1) the contents of the tarball are not affected, and 2) even if the initial tarball is not bit by bit the same that upstream release, at least future uploads of that same upstream version with Debian revisions can be regenerated just fine. In some cases, as the case for the test tarball util-linux_2.30.1.orig.tar.xz, recompressing is what makes it possible to reproduce the tarball (and thus import it with pristine-tar) possible at all: util-linux_2.30.1.orig.tar.xz can only be imported after being recompressed In other cases, if the current heuristics can t produce a reasonably small delta, recompressing makes a huge difference. It s the case for mumble_1.1.8.orig.tar.gz: with recompression, the delta produced from mumble_1.1.8.orig.tar.gz goes from 1.2MB, or 99% of the size to the original tarball, to 14.6KB, 1% of the size of original tarball Recompressing is not enabled by default, and can be enabled by passing the --recompress option. If you are using pristine-tar via a wrapper tool like gbp-buildpackage, you can use the $PRISTINE_TAR environment variable to set options that will affect any pristine-tar invocations. Also, even if you enable recompression, pristine-tar will only try it if the delta generations fails completely, of if the delta produced from the original tarball is too large. You can control what too large means by using the --recompress-threshold-bytes and --recompress-threshold-percent options. See the pristine-tar(1) manual page for details.

5 October 2017

Wouter Verhelst: Patching Firefox

At work, I help maintain a smartcard middleware that is provided to Belgian citizens who want to use their electronic ID card to, e.g., log on to government websites. This middleware is a piece of software that hooks into various browsers and adds a way to access the smartcard in question, through whatever APIs the operating system and the browser in question provide for that purpose. The details of how that is done differ between each browser (and in the case of Google Chrome, for the same browser between different operating systems); but for Firefox (and Google Chrome on free operating systems), this is done by way of a PKCS#11 module. For Firefox 57, mozilla decided to overhaul much of their browser. The changes are large and massive, and in some ways revolutionary. It's no surprise, therefore, that some of the changes break compatibility with older things. One of the areas in which breaking changes were made is in the area of extensions to the browser. Previously, Firefox had various APIs available for extensions; right now, all APIs apart from the WebExtensions API are considered "legacy" and support for them will be removed from Firefox 57 going forward. Since installing a PKCS#11 module manually is a bit complicated, and since the legacy APIs provided a way to do so automatically provided the user would first install an add-on (or provided the installer of the PKCS#11 module sideloads it), most parties who provide a PKCS#11 module for use with Firefox will provide an add-on to automatically install it. Since the alternative involves entering the right values in a dialog box that's hidden away somewhere deep in the preferences screen, the add-on option is much more user friendly. I'm sure you can imagine my dismay when I found out that there was no WebExtensions API to provide the same functionality. So, after asking around a bit, I filed bug 1357391 to get a discussion started. While it took some convincing initially to get people to understand the reasons for wanting such an API, eventually the bug was assigned the "P5" priority -- essentially, a "we understand the need and won't block it, but we don't have the time to implement it. Patches welcome, though" statement. Since having an add-on was something that work really wanted, and since I had the time, I got the go-ahead from management to look into implementing the required code myself. I made it obvious rather quickly that my background in Firefox was fairly limited, though, and so was assigned a mentor to help me through the process. Having been a Debian Developer for the past fifteen years, I do understand how to develop free software. Yet, the experience was different enough that still learned some new things about free software development, which was somewhat unexpected. Unfortunately, the process took much longer than I had hoped, which meant that the patch was not ready by the time Firefox 57 was branched off mozilla's "central" repository. The result of that is that while my patch has been merged into what will eventually become Firefox 58, it looks strongly as though it won't make it into Firefox 57. That's going to cause some severe headaches, which I'm not looking forward to; and while I can certainly understand the reasons for not wanting to grant the exception for the merge into 57, I can't help but feeling like this is a missed opportunity. Anyway, writing code for the massive Open Source project that mozilla is has been a load of fun, and in the process I've learned a lot -- not only about Open Source development in general, but also about this weird little thing that Javascript is. That might actually be useful for this other project that I've got running here. In closing, I'd like to thank Tomislav 'zombie' Jovanovic for mentoring me during the whole process, without whom it would have been doubtful if I would even have been ready by now. Apologies for any procedural mistakes I've made, and good luck in your future endeavours! :-)

3 October 2017

Iain R. Learmonth: Facebook Lies

In the past, I had a Facebook account. Long ago I deleted this account through the procedure outlined on their help pages. In theory, 14 days after I used this process my account would be irrevocably gone. This was all lies. My account was not deleted and yesterday I received an email:
Screenshot of the email I received from Facebook Screenshot of the email I received from Facebook
It took me a moment to figure it out, but what had happened here is someone had logged into my Facebook account using my email address and password. Facebook simply reactivated the account, which had not had its data deleted, as if I had logged in. This was possible because:
  1. Facebook was clinging to the hope that I would like to return
  2. The last time I used Facebook I didn t know what a password manager was and was using the same password for basically everything
When I logged back in, all I needed to provide to prove I was me was my date of birth. Given that old Facebook passwords are readily available from dumps (people think their accounts are gone, so why should they be changing their passwords?) and my date of birth is not secret either, this is not great. I followed the deletion procedure again and in 2 weeks (you can t immediately request deletion apparently) I ll check to see if the account is really gone. I ve updated the password so at least the deletion process can t be interrupted by whoever has that password (probably lots of people - it ll be in a ton of dumps where databases have been hacked). If it s still not gone, I hear you can just post obscene and offensive material until Facebook deletes you. I d rather not have to take that route though. If you re interested to see if you ve turned up in a hacked database dump yourself, I would recommend hibp. Update (2017-10-04): Thanks for all the comments. Sorry I haven t been able to reply to all of them. Discussion around this post occured at Hacker News if you would like to read more there. You can also read about a similar, and more frustrating, case that came up in the HN discussion.

2 October 2017

Antoine Beaupr : My free software activities, September 2017

Debian Long Term Support (LTS) This is my monthly Debian LTS report. I mostly worked on the git, git-annex and ruby packages this month but didn't have time to completely use my allocated hours because I started too late in the month.

Ruby I was hoping someone would pick up the Ruby work I submitted in August, but it seems no one wanted to touch that mess, understandably. Since then, new issues came up, and not only did I have to work on the rubygems and ruby1.9 package, but now the ruby1.8 package also had to get security updates. Yes: it's bad enough that the rubygems code is duplicated in one other package, but wheezy had the misfortune of having two Ruby versions supported. The Ruby 1.9 also failed to build from source because of test suite issues, which I haven't found a clean and easy fix for, so I ended up making test suite failures non-fatal in 1.9, which they were already in 1.8. I did keep a close eye on changes in the test suite output to make sure tests introduced in the security fixes would pass and that I wouldn't introduce new regressions as well. So I published the following advisories:
  • ruby 1.8: DLA-1113-1, fixing CVE-2017-0898 and CVE-2017-10784. 1.8 doesn't seem affected by CVE-2017-14033 as the provided test does not fail (but it does fail in 1.9.1). test suite was, before patch:
    2199 tests, 1672513 assertions, 18 failures, 51 errors
    
    and after patch:
    2200 tests, 1672514 assertions, 18 failures, 51 errors
    
  • rubygems: uploaded the package prepared in August as is in DLA-1112-1, fixing CVE-2017-0899, CVE-2017-0900, CVE-2017-0901. here the test suite passed normally.
  • ruby 1.9: here I used the used 2.2.8 release tarball to generate a patch that would cover all issues and published DLA-1114-1 that fixes the CVEs of the two packages above. the test suite was, before patches:
    10179 tests, 2232711 assertions, 26 failures, 23 errors, 51 skips
    
    and after patches:
    1.9 after patches (B): 10184 tests, 2232771 assertions, 26 failures, 23 errors, 53 skips
    

Git I also quickly issued an advisory (DLA-1120-1) for CVE-2017-14867, an odd issue affecting git in wheezy. The backport was tricky because it wouldn't apply cleanly and the git package had a custom patching system which made it tricky to work on.

Git-annex I did a quick stint on git-annex as well: I was able to reproduce the issue and confirm an approach to fixing the issue in wheezy, although I didn't have time to complete the work before the end of the month.

Other free software work

New project: feed2exec I should probably make a separate blog post about this, but ironically, I don't want to spend too much time writing those reports, so this will be quick. I wrote a new program, called feed2exec. It's basically a combination of feed2imap, rss2email and feed2tweet: it allows you to fetch RSS feeds and send them in a mailbox, but what's special about it, compared to the other programs above, is that it is more generic: you can basically make it do whatever you want on new feed items. I have, for example, replaced my feed2tweet instance with it, using this simple configuration:
[anarcat]
url = https://anarc.at/blog/index.rss
output = feed2exec.plugins.exec
args = tweet "%(title)0.70s %(link)0.70s"
The sample configuration file also has examples to talk with Mastodon, Pump.io and, why not, a torrent server to download torrent files available over RSS feeds. A trivial configuration can also make it work as a crude podcast client. My main motivation to work on this was that it was difficult to extend feed2imap to do what I needed (which was to talk to transmission to download torrent files) and rss2email didn't support my workflow (which is delivering to feed-specific mail folders). Because both projects also seemed abandoned, it seemed like a good idea at the time to start a new one, although the rss2email community has now restarted the project and may produce interesting results. As an experiment, I tracked my time working on this project. It turns out it took about 45 hours to write that software. Considering feed2exec is about 1400 SLOC, that's 30 lines of code per hour. I don't know if that's slow or fast, but it's an interesting metric for future projects. It sure seems slow to me, but we need to keep in mind those 30 lines of code don't include documentation and repeated head banging on the keyboard. For example, I found two issues with the upstream feedparser package which I use to parse feeds which also seems unmaintained, unfortunately. Feed2exec is beta software at this point, but it's working well enough for me and the design is much simpler than the other programs of the kind. The main issue people can expect from it at this point is formatting issues or parse errors on exotic feeds, and noisy error messages on network errors, all of which should be fairly easy to fix in the test suite. I hope it will be useful for the community and, as usual, I welcome contributions, help and suggestions on how to improve the software.

More Python templates As part of the work on feed2exec, I did cleanup a few things in the ecdysis project, mostly to hook tests up in the CI, improve on the advancedConfig logger and cleanup more stuff. While I was there, it turns out that I built a pretty decent basic CI configuration for Python on GitLab. Whereas the previous templates only had a non-working Django example, you should now be able to chose a Python template when you configure CI on GitLab 10 and above, which should hook you up with normal Python setup procedures like setup.py install and setup.py test.

Selfspy I mentioned working on a monitoring tool in my last post, because it was a feature from Workrave missing in SafeEyes. It turns out there is already such a tool called selfspy. I did an extensive review of the software to make sure it wouldn't leak out confidential information out before using it, and it looks, well... kind of okay. It crashed on me at least once so far, which is too bad because then it loses track of the precious activity. I have used it at least once to figure out what the heck I worked on during the day, so it's pretty useful. I particularly used it to backtrack my work on feed2exec as I didn't originally track my time on the project. Unfortunately, selfspy seems unmaintained. I have proposed a maintenance team and hopefully the project maintainer will respond and at least share access so we don't end up in a situation like linkchecker. I also sent a bunch of pull requests to fix some issues like being secure by default and fixing the build. Apart from the crash, the main issue I have found with the software is that it doesn't detect idle time which means certain apps are disproportionatly represented in statistics. There are also some weaknesses in the crypto that should be adressed for people that encrypt their database. Next step is to package selfspy in Debian which should hopefully be simple enough...

Restic documentation security As part of a documentation patch on the Restic backup software, I have improved on my previous Perl script to snoop on process commandline arguments. A common flaw in shell scripts and cron jobs is to pass secret material in the environment (usually safe) but often through commandline arguments (definitely not safe). The challenge, in this peculiar case, was the env binary, but the last time I encountered such an issue was with the Drush commandline tool, which was passing database credentials in clear to the mysql binary. Using my Perl sniffer, I could get to 60 checks per second (or 60Hz). After reimplementing it in Python, this number went up to 160Hz, which still wasn't enough to catch the elusive env command, which is much faster at hiding arguments than MySQL, in large part because it simply does an execve() once the environment is setup. Eventually, I just went crazy and rewrote the whole thing in C which was able to get 700-900Hz and did catch the env command about 10-20% of the time. I could probably have rewritten this by simply walking /proc myself (since this is what all those libraries do in the end) to get better result, but then my point was made. I was able to prove to the restic author the security issues that warranted the warning. It's too bad I need to repeat this again and again, but then my tools are getting better at proving that issue... I suspect it's not the last time I have to deal with this issue and I am happy to think that I can come up with an even more efficient proof of concept tool the next time around.

Ansible 101 After working on documentation last month, I ended up writing my first Ansible playbook this month, converting my tasksel list to a working Ansible configuration. This was a useful exercise: it allow me to find a bunch of packages which have been removed from Debian and provides much better usability than tasksel. For example, it provides a --diff argument that shows which packages are missing from a given setup. I am still unsure about Ansible. Manifests do seem really verbose and I still can't get used to the YAML DSL. I could probably have done the same thing with Puppet and just run puppet apply on the resulting config. But I must admit my bias towards Python is showing here: I can't help but think Puppet is going to be way less accessible with its rewrite in Clojure and C (!)... But then again, I really like Puppet's approach of having generic types like package or service rather than Ansible's clunky apt/yum/dnf/package/win_package types...

Pat and Ham radio After responding (too late) to a request for volunteers to help in Puerto Rico, I realized that my amateur radio skills were somewhat lacking in the "packet" (data transmission in ham jargon) domain, as I wasn't used to operate a Winlink node. Such a node can receive and transmit actual emails over the airwaves, for free, without direct access to the internet, which is very useful in disaster relief efforts. Through summary research, I stumbled upon the new and very promising Pat project which provides one of the first user-friendly Linux-compatible Winlink programs. I provided improvements on the documentation and some questions regarding compatibility issues which are still pending. But my pet issue is the establishment of pat as a normal internet citizen by using standard protocols for receiving and sending email. Not sure how that can be implemented, but we'll see. I am also hoping to upload an official Debian package and hopefully write more about this soon. Stay tuned!

Random stuff I ended up fixing my Kodi issue by starting it as a standalone systemd service, instead of gdm3, which is now completely disabled on the media box. I simply used the following /etc/systemd/service/kodi.service file:
[Unit]
Description=Kodi Media Center
After=systemd-user-sessions.service network.target sound.target
[Service]
User=xbmc
Group=video
Type=simple
TTYPath=/dev/tty7
StandardInput=tty
ExecStart=/usr/bin/xinit /usr/bin/dbus-launch --exit-with-session /usr/bin/kodi-standalone -- :1 -nolisten tcp vt7
Restart=on-abort
RestartSec=5
[Install]
WantedBy=multi-user.target
The downside of this is that it needs Xorg to run as root, whereas modern Xorg can now run rootless. Not sure how to fix this or where... But if I put needs_root_rights=no in Xwrapper.config, I get the following error in .local/share/xorg/Xorg.1.log:
[  2502.533] (EE) modeset(0): drmSetMaster failed: Permission denied
After fooling around with iPython, I ended up trying the xonsh shell, which is supposed to provide a bash-compatible Python shell environment. Unfortunately, I found it pretty unusable as a shell: it works fine to do Python stuff, but then all my environment and legacy bash configuration files were basically ignored so I couldn't get working quickly. This is too bad because the project looked very promising... Finally, one of my TLS hosts using a Let's Encrypt certificate wasn't renewing properly, and I figured out why. It turns out the ProxyPass command was passing everything to the backend, including the /.well-known requests, which obviously broke ACME verification. The solution was simple enough, disable the proxy for that directory:
ProxyPass /.well-known/ !

Antoine Beaupr : My free software activities, September 2017

Debian Long Term Support (LTS) This is my monthly Debian LTS report. I mostly worked on the git, git-annex and ruby packages this month but didn't have time to completely use my allocated hours because I started too late in the month.

Ruby I was hoping someone would pick up the Ruby work I submitted in August, but it seems no one wanted to touch that mess, understandably. Since then, new issues came up, and not only did I have to work on the rubygems and ruby1.9 package, but now the ruby1.8 package also had to get security updates. Yes: it's bad enough that the rubygems code is duplicated in one other package, but wheezy had the misfortune of having two Ruby versions supported. The Ruby 1.9 also failed to build from source because of test suite issues, which I haven't found a clean and easy fix for, so I ended up making test suite failures non-fatal in 1.9, which they were already in 1.8. I did keep a close eye on changes in the test suite output to make sure tests introduced in the security fixes would pass and that I wouldn't introduce new regressions as well. So I published the following advisories:
  • ruby 1.8: DLA-1113-1, fixing CVE-2017-0898 and CVE-2017-10784. 1.8 doesn't seem affected by CVE-2017-14033 as the provided test does not fail (but it does fail in 1.9.1). test suite was, before patch:
    2199 tests, 1672513 assertions, 18 failures, 51 errors
    
    and after patch:
    2200 tests, 1672514 assertions, 18 failures, 51 errors
    
  • rubygems: uploaded the package prepared in August as is in DLA-1112-1, fixing CVE-2017-0899, CVE-2017-0900, CVE-2017-0901. here the test suite passed normally.
  • ruby 1.9: here I used the used 2.2.8 release tarball to generate a patch that would cover all issues and published DLA-1114-1 that fixes the CVEs of the two packages above. the test suite was, before patches:
    10179 tests, 2232711 assertions, 26 failures, 23 errors, 51 skips
    
    and after patches:
    1.9 after patches (B): 10184 tests, 2232771 assertions, 26 failures, 23 errors, 53 skips
    

Git I also quickly issued an advisory (DLA-1120-1) for CVE-2017-14867, an odd issue affecting git in wheezy. The backport was tricky because it wouldn't apply cleanly and the git package had a custom patching system which made it tricky to work on.

Git-annex I did a quick stint on git-annex as well: I was able to reproduce the issue and confirm an approach to fixing the issue in wheezy, although I didn't have time to complete the work before the end of the month.

Other free software work

New project: feed2exec I should probably make a separate blog post about this, but ironically, I don't want to spend too much time writing those reports, so this will be quick. I wrote a new program, called feed2exec. It's basically a combination of feed2imap, rss2email and feed2tweet: it allows you to fetch RSS feeds and send them in a mailbox, but what's special about it, compared to the other programs above, is that it is more generic: you can basically make it do whatever you want on new feed items. I have, for example, replaced my feed2tweet instance with it, using this simple configuration:
[anarcat]
url = https://anarc.at/blog/index.rss
output = feed2exec.plugins.exec
args = tweet "%(title)0.70s %(link)0.70s"
The sample configuration file also has examples to talk with Mastodon, Pump.io and, why not, a torrent server to download torrent files available over RSS feeds. A trivial configuration can also make it work as a crude podcast client. My main motivation to work on this was that it was difficult to extend feed2imap to do what I needed (which was to talk to transmission to download torrent files) and rss2email didn't support my workflow (which is delivering to feed-specific mail folders). Because both projects also seemed abandoned, it seemed like a good idea at the time to start a new one, although the rss2email community has now restarted the project and may produce interesting results. As an experiment, I tracked my time working on this project. It turns out it took about 45 hours to write that software. Considering feed2exec is about 1400 SLOC, that's 30 lines of code per hour. I don't know if that's slow or fast, but it's an interesting metric for future projects. It sure seems slow to me, but we need to keep in mind those 30 lines of code don't include documentation and repeated head banging on the keyboard. For example, I found two issues with the upstream feedparser package which I use to parse feeds which also seems unmaintained, unfortunately. Feed2exec is beta software at this point, but it's working well enough for me and the design is much simpler than the other programs of the kind. The main issue people can expect from it at this point is formatting issues or parse errors on exotic feeds, and noisy error messages on network errors, all of which should be fairly easy to fix in the test suite. I hope it will be useful for the community and, as usual, I welcome contributions, help and suggestions on how to improve the software.

More Python templates As part of the work on feed2exec, I did cleanup a few things in the ecdysis project, mostly to hook tests up in the CI, improve on the advancedConfig logger and cleanup more stuff. While I was there, it turns out that I built a pretty decent basic CI configuration for Python on GitLab. Whereas the previous templates only had a non-working Django example, you should now be able to chose a Python template when you configure CI on GitLab 10 and above, which should hook you up with normal Python setup procedures like setup.py install and setup.py test.

Selfspy I mentioned working on a monitoring tool in my last post, because it was a feature from Workrave missing in SafeEyes. It turns out there is already such a tool called selfspy. I did an extensive review of the software to make sure it wouldn't leak out confidential information out before using it, and it looks, well... kind of okay. It crashed on me at least once so far, which is too bad because then it loses track of the precious activity. I have used it at least once to figure out what the heck I worked on during the day, so it's pretty useful. I particularly used it to backtrack my work on feed2exec as I didn't originally track my time on the project. Unfortunately, selfspy seems unmaintained. I have proposed a maintenance team and hopefully the project maintainer will respond and at least share access so we don't end up in a situation like linkchecker. I also sent a bunch of pull requests to fix some issues like being secure by default and fixing the build. Apart from the crash, the main issue I have found with the software is that it doesn't detect idle time which means certain apps are disproportionatly represented in statistics. There are also some weaknesses in the crypto that should be adressed for people that encrypt their database. Next step is to package selfspy in Debian which should hopefully be simple enough...

Restic documentation security As part of a documentation patch on the Restic backup software, I have improved on my previous Perl script to snoop on process commandline arguments. A common flaw in shell scripts and cron jobs is to pass secret material in the environment (usually safe) but often through commandline arguments (definitely not safe). The challenge, in this peculiar case, was the env binary, but the last time I encountered such an issue was with the Drush commandline tool, which was passing database credentials in clear to the mysql binary. Using my Perl sniffer, I could get to 60 checks per second (or 60Hz). After reimplementing it in Python, this number went up to 160Hz, which still wasn't enough to catch the elusive env command, which is much faster at hiding arguments than MySQL, in large part because it simply does an execve() once the environment is setup. Eventually, I just went crazy and rewrote the whole thing in C which was able to get 700-900Hz and did catch the env command about 10-20% of the time. I could probably have rewritten this by simply walking /proc myself (since this is what all those libraries do in the end) to get better result, but then my point was made. I was able to prove to the restic author the security issues that warranted the warning. It's too bad I need to repeat this again and again, but then my tools are getting better at proving that issue... I suspect it's not the last time I have to deal with this issue and I am happy to think that I can come up with an even more efficient proof of concept tool the next time around.

Ansible 101 After working on documentation last month, I ended up writing my first Ansible playbook this month, converting my tasksel list to a working Ansible configuration. This was a useful exercise: it allow me to find a bunch of packages which have been removed from Debian and provides much better usability than tasksel. For example, it provides a --diff argument that shows which packages are missing from a given setup. I am still unsure about Ansible. Manifests do seem really verbose and I still can't get used to the YAML DSL. I could probably have done the same thing with Puppet and just run puppet apply on the resulting config. But I must admit my bias towards Python is showing here: I can't help but think Puppet is going to be way less accessible with its rewrite in Clojure and C (!)... But then again, I really like Puppet's approach of having generic types like package or service rather than Ansible's clunky apt/yum/dnf/package/win_package types...

Pat and Ham radio After responding (too late) to a request for volunteers to help in Puerto Rico, I realized that my amateur radio skills were somewhat lacking in the "packet" (data transmission in ham jargon) domain, as I wasn't used to operate a Winlink node. Such a node can receive and transmit actual emails over the airwaves, for free, without direct access to the internet, which is very useful in disaster relief efforts. Through summary research, I stumbled upon the new and very promising Pat project which provides one of the first user-friendly Linux-compatible Winlink programs. I provided improvements on the documentation and some questions regarding compatibility issues which are still pending. But my pet issue is the establishment of pat as a normal internet citizen by using standard protocols for receiving and sending email. Not sure how that can be implemented, but we'll see. I am also hoping to upload an official Debian package and hopefully write more about this soon. Stay tuned!

Random stuff I ended up fixing my Kodi issue by starting it as a standalone systemd service, instead of gdm3, which is now completely disabled on the media box. I simply used the following /etc/systemd/service/kodi.service file:
[Unit]
Description=Kodi Media Center
After=systemd-user-sessions.service network.target sound.target
[Service]
User=xbmc
Group=video
Type=simple
TTYPath=/dev/tty7
StandardInput=tty
ExecStart=/usr/bin/xinit /usr/bin/dbus-launch --exit-with-session /usr/bin/kodi-standalone -- :1 -nolisten tcp vt7
Restart=on-abort
RestartSec=5
[Install]
WantedBy=multi-user.target
The downside of this is that it needs Xorg to run as root, whereas modern Xorg can now run rootless. Not sure how to fix this or where... But if I put needs_root_rights=no in Xwrapper.config, I get the following error in .local/share/xorg/Xorg.1.log:
[  2502.533] (EE) modeset(0): drmSetMaster failed: Permission denied
After fooling around with iPython, I ended up trying the xonsh shell, which is supposed to provide a bash-compatible Python shell environment. Unfortunately, I found it pretty unusable as a shell: it works fine to do Python stuff, but then all my environment and legacy bash configuration files were basically ignored so I couldn't get working quickly. This is too bad because the project looked very promising... Finally, one of my TLS hosts using a Let's Encrypt certificate wasn't renewing properly, and I figured out why. It turns out the ProxyPass command was passing everything to the backend, including the /.well-known requests, which obviously broke ACME verification. The solution was simple enough, disable the proxy for that directory:
ProxyPass /.well-known/ !

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