Search Results: "zed"

12 November 2017

Russ Allbery: Review: Night Moves

Review: Night Moves, by Pat Green
Publisher: Aquarius
Copyright: 2014
ISBN: 0-9909741-1-1
Format: Kindle
Pages: 159
In the fall of 2012, Pat Green was a preacher of a failing church, out of a job, divorced for six months, and feeling like a failure at every part of his life. He was living in a relative's house and desperately needed work and his father had been a taxi driver. So he got a job as a 6pm to 6am taxi driver in his home town of Joliet, Illinois. That job fundamentally changed his understanding of the people who live in the night, how their lives work, and what it means to try to help them. This is nonfiction: a collection of short anecdotes about life as a cab driver and the people who have gotten a ride in Green's cab. They're mostly five or six pages long, just a short story or window into someone's life. I ran across Pat Green's writing by following a sidebar link from a post on Patheos (probably from Love, Joy, Feminism, although I no longer remember). Green has an ongoing blog on Patheos about raising his transgender son (who appears in this collection as a lesbian daughter; he wasn't out yet as transgender when this was published), which is both a good sample of his writing and occasionally has excerpts from this book. Green's previous writing experience, as mentioned at several points in this collection, was newspaper columns in the local paper. It shows: these essays have the succinct, focused, and bite-sized property of a good newspaper article (or blog post). The writing is a little rough, particularly the remembered dialogue that occasionally falls into the awkward valley between dramatic, constructed fictional dialogue and realistic, in-the-moment speech. But the stories are honest and heartfelt and have the self-reflective genuineness of good preaching paired with a solid sense of narrative. Green tries to observe and report first, both the other person and his own reactions, and only then try to draw more general conclusions. This book is also very hard to read. It's not a sugar-coated view of people who live in the night of a city, nor is it constructed to produce happy endings. The people who Green primarily writes about are poor, or alone, or struggling. The story that got me to buy this book, about taking a teenage girl to a secret liaison that turned out to be secret because her liaison was another girl, is heartwarming but also one of the most optimistic stories here. A lot of people die or just disappear after being regular riders for some time. A lot of people are desperate and don't have any realistic way out. Some people, quite memorably, think they have a way out, and that way out closes on them. The subtitle of this book is "An Ex-Preacher's Journey to Hell in a Taxi" and (if you followed the link above) you'll see that Green is writing in the Patheos nonreligious section. The other theme of this collection is the church and its effect on the lives of people who are trying to make a life on the outskirts of society. That effect is either complete obliviousness or an active attempt to make their lives even worse. Green lays out the optimism that he felt early in the job, the hope that he could help someone the way a pastor would, guide her to resources, and how it went horribly wrong when those resources turned out to not be interested in helping her at all. And those stories repeat, and repeat. It's a book that makes it very clear that the actual practice of Christianity in the United States is not about helping poor or marginalized people, but there are certainly plenty of Christian resources for judging, hurting people, closing doors, and forcing abused people back into abusive situations, all in the name of God. I do hope some Christians read this and wince very hard. (And lest the progressive Christians get too smug, one of the stories says almost as brutal things about liberal ministries as the stories of conservative ones.) I came away feeling even more convinced by the merits of charities that just give money directly to poor people. No paternalism, no assuming that rich people know what they need, no well-meaning intermediary organizations with endless rules, just resources delivered directly to the people who most need resources. Ideally done by the government and called universal basic income. Short of constructing a functional government that builds working public infrastructure, and as a supplement even if one has such a government (since infrastructure can't provide everything), it feels like the most moral choice. Individual people may still stay mired in awful situations, but at least that isn't compounded by other people taking their autonomy away and dictating life to them in complete ignorance. This is a fairly short and inexpensive book. I found it very much worth reading, and may end up following Green's blog as well. There are moments of joy and moments of human connection, and the details of the day-to-day worries and work style of a taxi driver (in this case, one who drives a company car) are pretty interesting. (Green does skip over some parts for various reasons, such as a lot of the routine fares and most of the stories of violence, but does mention what he's skipping over.) But it's also a brutal book, because so many people are hurting and there isn't much Green can do about it except bear witness and respect them as people in a way that religion doesn't. Recommended, but brace yourself. Rating: 8 out of 10

8 November 2017

Dirk Eddelbuettel: RQuantLib 0.4.4: Several smaller updates

A shiny new (mostly-but-not-completely maintenance) release of RQuantLib, now at version 0.4.4, arrived on CRAN overnight, and will get to Debian shortly. This is the first release in over a year, and it it contains (mostly) a small number of fixes throughout. It also includes the update to the new DateVector and DatetimeVector classes which become the default with the upcoming Rcpp 0.12.14 release (just like this week's RcppQuantuccia release). One piece of new code is due to Fran ois Cocquemas who added support for discrete dividends to both European and American options. See below for the complete set of changes reported in the NEWS file. As with release 0.4.3 a little over a year ago, we will not have new Windows binaries from CRAN as I apparently have insufficient powers of persuasion to get CRAN to update their QuantLib libraries. So we need a volunteer. If someone could please build a binary package for Windows from the 0.4.4 sources, I would be happy to once again host it on the GHRR drat repo. Please contact me directly if you can help. Changes are listed below:

Changes in RQuantLib version 0.4.4 (2017-11-07)
  • Changes in RQuantLib code:
    • Equity options can now be analyzed via discrete dividends through two vectors of dividend dates and values (Francois Cocquemas in #73 fixing #72)
    • Some package and dependency information was updated in files DESCRIPTION and NAMESPACE.
    • The new Date(time)Vector classes introduced with Rcpp 0.12.8 are now used when available.
    • Minor corrections were applied to BKTree, to vanilla options for the case of intraday time stamps, to the SabrSwaption documentation, and to bond utilities for the most recent QuantLib release.

Courtesy of CRANberries, there is also a diffstat report for the this release. As always, more detailed information is on the RQuantLib page. Questions, comments etc should go to the rquantlib-devel mailing list off the R-Forge page. Issue tickets can be filed at the GitHub repo.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

7 November 2017

Rog rio Brito: Some activities of the day

Yesterday, I printed the first draft of the first chapter when my little boy was here and he was impressed with this strange object called a "printer". Before I printed what I needed, I fired up LibreOffice and chose the biggest font size that was available and let him type his first name by himself. He was quicker than I thought with a keyboard. After seeing me print his first name, he was jumping up and down with joy of having created something and even showed grandma and grandpa what he had done. He, then, wanted more and I taught him how to use that backspace key, what it meant and he wanted to type his full name. I let him and taught him that there is a key called space that he should type every time he wants to start a new word and, in the end, he typed his first two names. To my surprise, he memorized the icon with the printer (which I must say that I have to hunt every time, since it seems so similar to the adjacent ones!) and pressed this new key called "Enter". When he pressed, he wasn't expecting the printer on his right to start making noises and printing his name. He was so excited and it was so nice to see his reaction full of joy to get a job done! I am thinking of getting a spare computer, building it with him and for him, so that he can call it his computer every time he comes to see daddy. As a serendipitous situation, Packt Publishing offered yesterday their title "Python Projects for Kids". Unfortunately, he does not yet know how to read, but I guess that the right age is coming soon, which is a good thing to make him be educated "the right way" (that is, with the best support, teaching and patience that I can give him). Anyway, I printed the first draft of the first chapter and today I have to turn it in. As I write this, I am downloading a virtual machine from Microsoft to try to install Java on it. Let me see if it works. I have none of the virtualization options used, tough the closest seems to be virtualbox. Let me cross my fingers. In other news, I updated some of the tags of very old posts of this blog, and I am seriously thinking about switching from [ikiwiki][0] to another blog platform. It is slow, very slow on my system with the repositories that I have, especially on my armel system. Some non-interpreted system would be best, but I don't know if such a thing even exists. But the killer problem is that it doesn't support easily the typing of Mathematics (even though a 3rd party plugin for MathJax exists). On the other hand, I just received an answer on twitter from @telegram and it was nice:
Hello, Telegram supports bold and italic. You can type **bold** and __italic__. On mobile, you can also highlight text for this as well.
It is nice that this works with telegram-desktop too. Besides that, I filed some bugs on Debian's BTS, responded to some issues on my projects on GitHub (I'm slowly getting back on maintaining things) and file wishlist bugs on some other projects. Oh, and I grabbed a copy of "Wonder woman" ("Mulher Maravilha") and "Despicable Me 3" ("Meu Malvado Favorito 3") dubbed in Brazilian Portuguese for my son. I have to convert the audio from AAC-LC in 6 channels to AC3 or to stereo. Otherwise, my TVs have problem with the videos (one refuses to play the entire file and another plays the audio with sounds of hiccups). Edit: After converting the VirtualBox image taken from Microsoft, I could easily use qemu/kvm to create screenshots of the installation of Java. The command that I used (for future reference) is: qemu-system-x86_64 -enable-kvm -m 4096 -smp 2 -net nic,model=e1000 -net user -soundhw ac97 -drive index=0,media=disk,cache=unsafe,file=win7.qcow2 Edit: Fixed some typos.

6 November 2017

Jonathan Dowland: Coil

Peter Christopherson and Jhonn Balance, from [Santa Sangre](https://santasangremagazine.wordpress.com/2014/11/16/the-angelic-conversation-in-remembrance-of-coil/) Peter Christopherson and Jhonn Balance, from Santa Sangre
A friend asked me to suggest five tracks by Coil that gave an introduction to their work. Trying to summarize Coil in 5 tracks is tough. I think it's probably impossible to fairly summarize Coil with any subset of their music, for two reasons. Firstly, their music was the output of their work but I don't think is really the whole of the work itself. There's a real mystique around them. They were deeply interested in arcania, old magic, Aleister Crowley, scatology; they were both openly and happily gay and their work sometimes explored their experiences in various related underground scenes and sub-cultures; they lost friends to HIV/AIDS and that had a profound impact on them. They had a big influence on some people who discovered them who were exploring their own sexualities at the time and might have felt excluded from mainstream society. They frequently explored drugs, meditation and other ways to try to expand and open their minds; occultism. They were also fiercely anti-commercial, their stuff was released in limited quantities across a multitude of different music labels, often under different names, and often paired with odd physical objects, runes, vials of blood, etc. Later fascinations included paganism and moon worship. I read somewhere that they literally cursed one of their albums. Secondly, part of their "signature" was the lack of any consistency in their work, or to put it another way, their style over time varied enormously. I'm also not necessarily well-versed in all their stuff, I'm part way on this journey myself... but these are tracks which stand out at least from the subset I've listened to. Both original/core members of Coil have passed away and the legal status of their catalogue is in a state of limbo. Some of these songs are available on currently-in-print releases, but all such releases are under dispute by some associate or other.

1. Heaven's Blade Like (probably) a lot of Coil songs, this one exists in multiple forms, with some dispute about which are canonical, which are officially sanctioned, etc. the video linked above actually contains 5 different versions, but I've linked to a time offset to the 4th: "Heaven's Blade (Backwards)". This version was the last to come to light with the recent release of "Backwards", an album originally prepared in the 90s at Trent Reznor's Nothing Studios in New Orleans, but not finished or released. The circumstances around its present-day release, as well as who did what to it and what manipulation may have been performed to the audio a long time after the two core members had passed, is a current topic in fan circles. Despite that, this is my preferred version. You can choose to investigate the others, or not, at your own discretion.

2. how to destroy angels (ritual music for the accumulation of male sexual energy) A few years ago, "guidopaparazzi", a user at the Echoing the Sound music message board attempted to listen to every Coil release ever made and document the process. He didn't do it chronologically, leaving the EPs until near the end, which is when he tackled this one (which was the first release by Coil, and was the inspiration behind the naming of Trent Reznor's one-time side project "How To Destroy Angels"). Guido seemed to think this was some kind of elaborate joke. Personally I think it's a serious piece and there's something to it but this just goes to show, different people can take things in entirely different ways. Here's Guido's review, and you can find the rest of his reviews linked from that one if you wish. https://archive.org/details/Coil-HowToDestroyAngels1984

3. Red Birds Will Fly Out Of The East And Destroy Paris In A Night Both "Musick To Play In The Dark" volumes (one and two) are generally regarded as amongst the most accessible entry points to the Coil discography. This is my choice of cut from volume 1. For some reason this reminds me a little of some of the background music from the game "Unreal Tournament". I haven't played that in at least 15 years. I should go back and see if I can figure out why it does. The whole EP is worth a listen, especially at night. https://archive.org/details/CoilMusickToPlayInTheDarkVol1/Coil+-+Musick+To+Play+In+The+Dark+Vol+1+-+2+Red+Birds+Will+Fly+Out+Of+The+East+And+Destroy+Paris+In+A+Night.flac

4. Things Happen It's tricky to pick a track from either "Love's Secret Domain" or "Horse Rotorvator"; there are other choices which I think are better known and loved than this one but it's one that haunted me after I first heard it for one reason or another, so here it is.

5. The Anal Staircase Track 1 from Horse Rotorvator. What the heck is a Horse Rotorvator anyway? I think it was supposed to have been a lucid nightmare experienced by the vocalist Jhonn Balance. So here they wrote a song about anal sex. No messing about, no allusion particularly, but why should there be? https://archive.org/details/CoilHorseRotorvator2001Remaster/Coil+-+Horse+Rotorvator+%5B2001+remaster%5D+-+01+The+Anal+Staircase.flac

Bonus 6th: 7-Methoxy-B-Carboline (Telepathine) From the drone album "Time Machines", which has just been re-issued by DIAS records, who describe it as "authorized". Each track is titled by the specific combination of compounds that inspired its composition, supposedly. Or, perhaps it's a "recommended dosing" for listening along. https://archive.org/details/TimeMachines-TimeMachines

Post-script If those piqued your interest, there's some decent words and a list of album suggestions in this Vinyl Factory article. Finally, if you can track them down, Stuart Maconie had two radio shows about Coil on his "Freak Zone" programme. The main show discusses the release of "Backwards", including an interview with collaborator Danny Hyde, who was the main person behind the recent re-issue. The shorter show is entitled John Doran uncoils Coil. Guest John Doran from The Quietus discusses the group and their history interspersed with Coil tracks and tracks from their contemporaries. Interestingly they chose a completely different set of 5 tracks to me.

John Goerzen: The Yellow House Phone Company (Featuring Asterisk and an 11-year-old)

Well Jacob, do you think we should set up our own pretend phone company in the house? We can DO THAT? Yes! Then yes. Yes! YES YES YESYESYESYES YES! Let s do it, dad! Not long ago, my parents had dug up the old phone I used back in the day. We still have a landline, and Jacob was having fun discovering how an analog phone works. I told him about the special number he could call to get the time and temperature read out to him. He discovered what happens if you call your own number and hang up. He figured out how to play Mary Had a Little Lamb using touchtone keys (after a slightly concerned lecture from me setting out some rules to make sure his musical dialing wouldn t result in any, well, dialing.) He was hooked. So I thought that taking it to the next level would be a good thing for a rainy day. I have run Asterisk before, though I had unfortunately gotten rid of most of my equipment some time back. But I found a great deal on a Cisco 186 ATA (Analog Telephone Adapter). It has two FXS lines (FXS ports simulate the phone company, and provide dialtone and ring voltage to a connected phone), and of course hooks up to the LAN. We plugged that in, and Jacob was amazed to see its web interface come up. I had to figure out how to configure it (unfortunately, it uses SCCP rather than SIP, and figuring out Asterisk s chan_skinny took some doing, but we got there.) I set up voicemail. He loved it. He promptly figured out how to record his own greetings. We set up a second phone on the other line, so he could call between them. The cordless phones in our house support SIP, so I configured one of them as a third line. He spent a long time leaving himself messages. IMG_3465 Pretty soon we both started having ideas. I set up extension 777, where he could call for the time. Then he wanted a way to get the weather forecast. Well, weather-util generates a text-based report. With it, a little sed and grep tweaking, the espeak TTS engine, and a little help from sox, I had a shell script worked up that would read back a forecast whenever he called a certain extension. He was super excited! That s great, dad! Can it also read weather alerts too? Sure! weather-util has a nice option just for that. Both boys cackled as the system tried to read out the NWS header (their timestamps like 201711031258 started with two hundred one billion ) Then I found an online source for streaming NOAA Weather Radio feeds Jacob enjoys listening to weather radio and I set up another extension he could call to listen to that. More delight! But it really took off when I asked him, Would you like to record your own menu? You mean those things where it says press 1 or 2 for this or that? Yes. WE CAN DO THAT? Oh yes! YES, LET S DO IT RIGHT NOW! So he recorded a menu, then came and hovered by me while I hacked up extensions.conf, then eagerly went back to the phone to try it. Oh the excitement of hearing hisown voice, and finding that it worked! Pretty soon he was designing sub-menus ( OK Dad, so we ll set it up so people can press 2 for the weather, and then choose if they want weather radio or the weather report. I m recording that now. Got it? ) He has informed me that next Saturday we will build an intercom system like we have at school. I m going to have to have some ideas on how to tie Squeezebox in with Asterisk to make that happen, I think. Maybe this will do.

2 November 2017

Antoine Beaupr : October 2017 report: LTS, feed2exec beta, pandoc filters, git mediawiki

Debian Long Term Support (LTS) This is my monthly Debian LTS report. This time I worked on the famous KRACK attack, git-annex, golang and the continuous stream of GraphicsMagick security issues.

WPA & KRACK update I spent most of my time this month on the Linux WPA code, to backport it to the old (~2012) wpa_supplicant release. I first published a patchset based on the patches shipped after the embargo for the oldstable/jessie release. After feedback from the list, I also built packages for i386 and ARM. I have also reviewed the WPA protocol to make sure I understood the implications of the changes required to backport the patches. For example, I removed the patches touching the WNM sleep mode code as that was introduced only in the 2.0 release. Chunks of code regarding state tracking were also not backported as they are part of the state tracking code introduced later, in 3ff3323. Finally, I still have concerns about the nonce setup in patch #5. In the last chunk, you'll notice peer->tk is reset, to_set to negotiate a new TK. The other approach I considered was to backport 1380fcbd9f ("TDLS: Do not modify RNonce for an TPK M1 frame with same INonce") but I figured I would play it safe and not introduce further variations. I should note that I share Matthew Green's observations regarding the opacity of the protocol. Normally, network protocols are freely available and security researchers like me can easily review them. In this case, I would have needed to read the opaque 802.11i-2004 pdf which is behind a TOS wall at the IEEE. I ended up reading up on the IEEE_802.11i-2004 Wikipedia article which gives a simpler view of the protocol. But it's a real problem to see such critical protocols developed behind closed doors like this. At Guido's suggestion, I sent the final patch upstream explaining the concerns I had with the patch. I have not, at the time of writing, received any response from upstream about this, unfortunately. I uploaded the fixed packages as DLA 1150-1 on October 31st.

Git-annex The next big chunk on my list was completing the work on git-annex (CVE-2017-12976) that I started in August. It turns out doing the backport was simpler than I expected, even with my rusty experience with Haskell. Type-checking really helps in doing the right thing, especially considering how Joey Hess implemented the fix: by introducing a new type. So I backported the patch from upstream and notified the security team that the jessie and stretch updates would be similarly easy. I shipped the backport to LTS as DLA-1144-1. I also shared the updated packages for jessie (which required a similar backport) and stretch (which didn't) and those Sebastien Delafond published those as DSA 4010-1.

Graphicsmagick Up next was yet another security vulnerability in the Graphicsmagick stack. This involved the usual deep dive into intricate and sometimes just unreasonable C code to try and fit a round tree in a square sinkhole. I'm always unsure about those patches, but the test suite passes, smoke tests show the vulnerability as fixed, and that's pretty much as good as it gets. The announcement (DLA 1154-1) turned out to be a little special because I had previously noticed that the penultimate announcement (DLA 1130-1) was never sent out. So I made a merged announcement to cover both instead of re-sending the original 3 weeks late, which may have been confusing for our users.

Triage & misc We always do a bit of triage even when not on frontdesk duty, so I: I also did smaller bits of work on: The latter reminded me of the concerns I have about the long-term maintainability of the golang ecosystem: because everything is statically linked, an update to a core library (say the SMTP library as in CVE-2017-15042, thankfully not affecting LTS) requires a full rebuild of all packages including the library in all distributions. So what would be a simple update in a shared library system could mean an explosion of work on statically linked infrastructures. This is a lot of work which can definitely be error-prone: as I've seen in other updates, some packages (for example the Ruby interpreter) just bit-rot on their own and eventually fail to build from source. We would also have to investigate all packages to see which one include the library, something which we are not well equipped for at this point. Wheezy was the first release shipping golang packages but at least it's shipping only one... Stretch has shipped with two golang versions (1.7 and 1.8) which will make maintenance ever harder in the long term.
We build our computers the way we build our cities--over time, without a plan, on top of ruins. - Ellen Ullman

Other free software work This month again, I was busy doing some serious yak shaving operations all over the internet, on top of publishing two of my largest LWN articles to date (2017-10-16-strategies-offline-pgp-key-storage and 2017-10-26-comparison-cryptographic-keycards).

feed2exec beta Since I announced this new project last month I have released it as a beta and it entered Debian. I have also wrote useful plugins like the wayback plugin that saves pages on the Wayback machine for eternal archival. The archive plugin can also similarly save pages to the local filesystem. I also added bash completion, expanded unit tests and documentation, fixed default file paths and a bunch of bugs, and refactored the code. Finally, I also started using two external Python libraries instead of rolling my own code: the pyxdg and requests-file libraries, the latter which I packaged in Debian (and fixed a bug in their test suite). The program is working pretty well for me. The only thing I feel is really missing now is a retry/fail mechanism. Right now, it's a little brittle: any network hiccup will yield an error email, which are readable to me but could be confusing to a new user. Strangely enough, I am particularly having trouble with (local!) DNS resolution that I need to look into, but that is probably unrelated with the software itself. Thankfully, the user can disable those with --loglevel=ERROR to silence WARNINGs. Furthermore, some plugins still have some rough edges. For example, The Transmission integration would probably work better as a distinct plugin instead of a simple exec call, because when it adds new torrents, the output is totally cryptic. That plugin could also leverage more feed parameters to save different files in different locations depending on the feed titles, something would be hard to do safely with the exec plugin now. I am keeping a steady flow of releases. I wish there was a way to see how effective I am at reaching out with this project, but unfortunately GitLab doesn't provide usage statistics... And I have received only a few comments on IRC about the project, so maybe I need to reach out more like it says in the fine manual. Always feels strange to have to promote your project like it's some new bubbly soap... Next steps for the project is a final review of the API and release production-ready 1.0.0. I am also thinking of making a small screencast to show the basic capabilities of the software, maybe with asciinema's upcoming audio support?

Pandoc filters As I mentioned earlier, I dove again in Haskell programming when working on the git-annex security update. But I also have a small Haskell program of my own - a Pandoc filter that I use to convert the HTML articles I publish on LWN.net into a Ikiwiki-compatible markdown version. It turns out the script was still missing a bunch of stuff: image sizes, proper table formatting, etc. I also worked hard on automating more bits of the publishing workflow by extracting the time from the article which allowed me to simply extract the full article into an almost final copy just by specifying the article ID. The only thing left is to add tags, and the article is complete. In the process, I learned about new weird Haskell constructs. Take this code, for example:
-- remove needless blockquote wrapper around some tables
--
-- haskell newbie tips:
--
-- @ is the "at-pattern", allows us to define both a name for the
-- construct and inspect the contents as once
--
--   is the "empty record pattern": it basically means "match the
-- arguments but ignore the args"
cleanBlock (BlockQuote t@[Table  ]) = t
Here the idea is to remove <blockquote> elements needlessly wrapping a <table>. I can't specify the Table type on its own, because then I couldn't address the table as a whole, only its parts. I could reconstruct the whole table bits by bits, but it wasn't as clean. The other pattern was how to, at last, address multiple string elements, which was difficult because Pandoc treats spaces specially:
cleanBlock (Plain (Strong (Str "Notifications":Space:Str "for":Space:Str "all":Space:Str "responses":_):_)) = []
The last bit that drove me crazy was the date parsing:
-- the "GAByline" div has a date, use it to generate the ikiwiki dates
--
-- this is distinct from cleanBlock because we do not want to have to
-- deal with time there: it is only here we need it, and we need to
-- pass it in here because we do not want to mess with IO (time is I/O
-- in haskell) all across the function hierarchy
cleanDates :: ZonedTime -> Block -> [Block]
-- this mouthful is just the way the data comes in from
-- LWN/Pandoc. there could be a cleaner way to represent this,
-- possibly with a record, but this is complicated and obscure enough.
cleanDates time (Div (_, [cls], _)
                 [Para [Str month, Space, Str day, Space, Str year], Para _])
    cls == "GAByline" = ikiwikiRawInline (ikiwikiMetaField "date"
                                           (iso8601Format (parseTimeOrError True defaultTimeLocale "%Y-%B-%e,"
                                                           (year ++ "-" ++ month ++ "-" ++ day) :: ZonedTime)))
                        ++ ikiwikiRawInline (ikiwikiMetaField "updated"
                                             (iso8601Format time))
                        ++ [Para []]
-- other elements just pass through
cleanDates time x = [x]
Now that seems just dirty, but it was even worse before. One thing I find difficult in adapting to coding in Haskell is that you need to take the habit of writing smaller functions. The language is really not well adapted to long discourse: it's more about getting small things connected together. Other languages (e.g. Python) discourage this because there's some overhead in calling functions (10 nanoseconds in my tests, but still), whereas functions are a fundamental and important construction in Haskell that are much more heavily optimized. So I constantly need to remind myself to split things up early, otherwise I can't do anything in Haskell. Other languages are more lenient, which does mean my code can be more dirty, but I feel get things done faster then. The oddity of Haskell makes frustrating to work with. It's like doing construction work but you're not allowed to get the floor dirty. When I build stuff, I don't mind things being dirty: I can cleanup afterwards. This is especially critical when you don't actually know how to make things clean in the first place, as Haskell will simply not let you do that at all. And obviously, I fought with Monads, or, more specifically, "I/O" or IO in this case. Turns out that getting the current time is IO in Haskell: indeed, it's not a "pure" function that will always return the same thing. But this means that I would have had to change the signature of all the functions that touched time to include IO. I eventually moved the time initialization up into main so that I had only one IO function and moved that timestamp downwards as simple argument. That way I could keep the rest of the code clean, which seems to be an acceptable pattern. I would of course be happy to get feedback from my Haskell readers (if any) to see how to improve that code. I am always eager to learn.

Git remote MediaWiki Few people know that there is a MediaWiki remote for Git which allow you to mirror a MediaWiki site as a Git repository. As a disaster recovery mechanism, I have been keeping such a historical backup of the Amateur radio wiki for a while now. This originally started as a homegrown Python script to also convert the contents in Markdown. My theory then was to see if we could switch from Mediawiki to Ikiwiki, but it took so long to implement that I never completed the work. When someone had the weird idea of renaming a page to some impossible long name on the wiki, my script broke. I tried to look at fixing it and then remember I also had a mirror running using the Git remote. It turns out it also broke on the same issue and that got me looking in the remote again. I got lost in a zillion issues, including fixing that specific issue, but I especially looked at the possibility of fetching all namespaces because I realized that the remote fetches only a part of the wiki by default. And that drove me to submit namespace support as a patch to the git mailing list. Finally, the discussion came back to how to actually maintain that contrib: in git core or outside? Finally, it looks like I'll be doing some maintenance that project outside of git, as I was granted access to the GitHub organisation...

Galore Yak Shaving Then there's the usual hodgepodge of fixes and random things I did over the month.
There is no [web extension] only XUL! - Inside joke

1 November 2017

Bernd Zeimetz: Connecting your 3D printer to OctoPrint automatically

Recently I joined the group of 3d printer owners and OctoPrint users. After some days I got annoyed by the fact that so far nobody seems to have thought about automatically connecting a printer to OctoPrint after turning the printer on. If you start OctoPrint after your printer, everything works fine. But here OctoPrint runs 24 7 but I turn off the printer when it is done with printing. My solution of the problem is based on udev and systemd and should work on most recent Linux installations.

James McCoy: Monthly FLOSS activity - 2017/10 edition

Debian subversion vim
libvterm
pangoterm
vim-gnupg
neovim
vim

31 October 2017

Chris Lamb: Free software activities in October 2017

Here is my monthly update covering what I have been doing in the free software world in October 2017 (previous month):
Reproducible builds

Whilst anyone can inspect the source code of free software for malicious flaws, most software is distributed pre-compiled to end users. The motivation behind the Reproducible Builds effort is to allow verification that no flaws have been introduced either maliciously or accidentally during this compilation process by promising identical results are always generated from a given source, thus allowing multiple third-parties to come to a consensus on whether a build was compromised. I have generously been awarded a grant from the Core Infrastructure Initiative to fund my work in this area. This month I:


I also made the following changes to our tooling:
diffoscope

diffoscope is our in-depth and content-aware diff utility that can locate and diagnose reproducibility issues.

  • Improve names in output of "internal" binwalk members. (#877525).
  • Don't crash on malformed md5sums files. (#877473).
  • Omit misleading "any of" prefix when only complaining about a single module on import. [...]
  • Adjust tests as ps2ascii now varies its output on timezone. [...]

strip-nondeterminism

strip-nondeterminism is our tool to remove specific non-deterministic results from a completed build.

  • Clojure considers .class file to be stale if it shares the same timestamp of the .clj. We thus adjust the timestamps of the .clj to always be younger. (#877418).
  • Print a message in --verbose mode if no canonical time was specified. [...]

buildinfo.debian.net

buildinfo.debian.net is my experiment into how to process, store and distribute .buildinfo files after the Debian archive software has processed them.

  • Always show SHA-256 checksums, regardless of the browser viewport size. [...]
  • Add an API endpoint to fetch specific .buildinfo files for a certain package/version/architecture. [...]


Debian My activities as the current Debian Project Leader are covered in my "Bits from the DPL" email to the debian-devel-announce mailing list.
Patches contributed
  • devscripts: Please print the actual arguments debuild makes to Lintian. (#880124)
  • hw-detect: Drop reference to floppy disks; it's almost 2018. (#880122)
  • debci:
    • Use deb.debian.org over http.debian.net. (#879654)
    • Document how to use an alternative mirror. (#879655)

Debian LTS

This month I have been paid to work 18 hours on Debian Long Term Support (LTS). In that time I did the following:
  • "Frontdesk" duties, triaging CVEs, etc.
  • Followed up on a large number of upstream "pings" that have been left dormant.
  • Issued DLA 1121-1 to fix an out-of-bounds read vulnerability in curl where a malicious FTP server could abuse this to prevent clients from interacting with it.
  • Issued DLA 1123-1 for the "Go" programming language where an attacker could generate a MIME request such that the server ran out of file descriptors.
  • Issued DLA 1126-1 for the libxfont font selection and rasterisation library, correcting two vulnerabilities, both involving the library being tricked into reading invalid/random memory.
  • Issued DLA 1134-1 for sdl-image1.2, an image loading library. A maliciously-crafted .xcf file could cause a stack-based buffer overflow resulting in potential code execution.

Uploads
  • python-django:
    • 2.0~beta1-1 New upstream 2.x release.
    • 1.11.6-1 New upstream bugfix release.
  • gunicorn (19.6.0-10+deb9u1) Prepared a release for stable to avoid a runtime dependency on a compiler. (#877722)
  • redis:
    • 4:4.0.2-3:
      • Drop the Debian-specific /etc/redis/redis-server.pre-up.d (etc.) hooks and remove them if unchanged.
      • Include systemd redis-server@.service and redis-sentinel@.service template files to easily run multiple Redis instances. (#877702)
      • Patch redis.conf and sentinel.conf with quilt instead of maintaining our own versions under debian/.
    • 4:4.0.2-4:
      • Add input validity checking to cluster config slot numbers to fix CVE-2017-15047. (#878076)
      • Drop debian/bin/generate-parts now we aren't calling it.
      • Correct Bash-ism in NEWS file.
    • 4:4.0.2-5: Replace the existing patch for CVE-2017-15047 with an upstream-blessed version that covers another case.
  • redisearch (0.21.3-5) Initial release.
  • docbook2man (2.0.0-40) Correct spelling mistakes in binaries and other misc packaging tidying.
  • python-redis (2.10.6-1) New upstream release.
  • bfs (1.1.3-1) New upstream release.

FTP Team

As a Debian FTP assistant I ACCEPTed 103 packages: amcheck, argagg, binutils, blockui, bro-pkg, chkservice, citus, django-axes, docker-containerd, doctest, dtkwidget, duktape, feed2exec, fontforge, fonttools, gcc-8, gcc-8-cross, generator-scripting-language, gitgraph.js, haskell-uri-encode, hoel, iniparser, its, jquery-areyousure, kodi, libcatmandu-mods-perl, libcatmandu-template-perl, libcatmandu-xml-perl, libcatmandu-xsd-perl, libcode-tidyall-plugin-sortlines-naturally-perl, libgdamm5.0, libinfinity, libmods-record-perl, libreoffice-dictionaries, libset-intervaltree-perl, libsodium, linux, linux-grsec, ltsp-manager, lxqt-themes, mailman3-core, measurement-kit, mini-buildd, musescore, node-babel, node-babel-eslint, node-babel-loader, node-babel-plugin-add-module-exports, node-babel-plugin-transform-define, node-gulp-newer, node-regenerate-unicode-properties, node-regexpu-core, node-regjsparser, node-unicode-data, node-unicode-loose-match, openjdk-9, orafce, pgaudit, pgsql-ogr-fdw, pk4, postgresql-mysql-fdw, powa-archivist, python-azure-devtools, python-colormap, python-darkslide, python-dotenv, python-karborclient, python-logfury, python-lupa, python-marshmallow, python-murano-pkg-check, python-octaviaclient, python-pathspec, python-pgpy, python-pydub, python-randomize, python-sabyenc, python-searchlightclient, python-stestr, python-subunit2sql, python-twitter, python-utils, python-wsgilog, r-cran-bindr, r-cran-desc, r-cran-hms, r-cran-readstata13, r-cran-rprojroot, r-cran-wikidatar, r-cran-wikipedir, r-cran-wikitaxa, repmgr, requests-file, resteasy3.0, sdl-kitchensink, stardicter, systemd-el, thunderbird, tomcat8.0, uwsgi-plugin-luajit, uwsgi-plugin-mongo, uwsgi-plugin-php & uwsgi-plugin-v8. I additionally filed 3 RC bugs against packages that had incomplete debian/copyright files against: fonttools, generator-scripting-language & libsodium.

30 October 2017

Norbert Preining: Inconsistent version numbers in subversion

Update 2017-10-31: The developers of Subversion were a bit surprised, but it turned out to be a genuine bug. The bug has been fixed the same day. The TeX Live project uses Subversion as its main repository. Reasons for that there are many, see my blog post on svn and git. But today I realized that subversion is broken, badly broken, because one can easily end up with inconsistent version numbers. To understand why this is a problem, I restart from the already linked blog: Our packages have revision numbers based on the latest change revision of all the contained files. Since subversion has a linear history and central repository, this guarantees that in contrast to version numbers provided by authors the revision numbers are strictly increasing . Well, it turned out that this assumption was wrong. Because it is easy to trick subversion to have wrong revision numbers for files. Consider the following flow: In our case we have files listing other packages, and they are getting moved around at times. In this case one package was moved from one collection to another and back. Now, if user A does svn up between revision A+n and A+n+m, then the final revision in his checkout of file xxx will be A+n+m. But a user B that does NOT do svn up between A+n and A+n+m will end up with a final revision of A for file xxx in his checkout. And boooom, revisions are different, although the files are in sync with the server. I cannot grasp what the developers of subversion thought about here, but I consider it deeply broken by design. One more reason the rewrite all our distribution scripts to work with git instead of subversion.

26 October 2017

Russ Allbery: Review: Waypoint Kangaroo

Review: Waypoint Kangaroo, by Curtis C. Chen
Series: Kangaroo #1
Publisher: Thomas Dunne
Copyright: June 2016
ISBN: 1-250-08179-3
Format: Kindle
Pages: 312
Disclaimer: Curtis was a classmate of mine at Stanford and part of the same social circle. That was a surprisingly long time ago. Kangaroo is a spy (and, for this book, you should think James Bond). Agency training, fake identities, lots of gadgets, grumpy yet ridiculously competent support staff... the typical package. But Kangaroo also has a special power, which is the entire reason he ended up in the position he has. He's apparently the only person in the world who can open the pocket: a hole into another dimension, which can function as infinite storage and quite a bit more. Waypoint Kangaroo opens with the tail end of a mission and Kangaroo in action, as an introduction to Kangaroo's first-person narrative voice, job, and the capabilities of the pocket. But the real story starts when Kangaroo is sent on vacation. The office is being audited, Kangaroo hasn't had time off basically ever, and his boss insists on a trip to Mars on the space equivalent of a cruise ship. No work. An expense account. Just relax and have fun. Kangaroo isn't sure he knows how to not work. Or how to avoid boredom when trying hard to not work. It leads to probably ill-advised decisions like falling in love at first glance with the chief engineer, or going on entirely unauthorized spacewalks in the middle of the night. It's very lucky for him that the captain of this commercial cruise ship appears to also work for his agency. And it's good for his inability to stop working that there's a murder on board. For a first novel, this is refreshingly free of a lot of first novel problems. It's lean, well-structured, easy to follow, moves right along, and doesn't feel over-stuffed with exposition or world-building. There's an interplanetary war in the past background, and of course a lot of loving description of the precise mechanics of the pocket and the tricks with momentum and retrieval Kangaroo can do with it, but the book never falls into too much explanation. And the plot is satisfyingly twisty. It's an action story plot, to be clear: don't expect deep puzzles or complex deduction. But there are enough players and hidden motives to keep things interesting. The downside is that I didn't like Kangaroo very much. He's a bit of an ass. Some of this goes with the spy novel territory, and some of it is good (if occasionally grating) characterization. Kangaroo doesn't know how to turn off the part of his brain that makes everything a mission. But his flippant, know-it-all attitude got on my nerves after a book full of first-person narration, and while (full credit to Curtis here) the romance in this book is clearly consensual and stays well away from the creepy romances so common in spy stories, the love-at-first sight bits and some of Kangaroo's awkward reactions provoked more eye-rolling than enjoyment. A lot of this is just personal taste, but that's the peril of books told with first-person narration. The reader has to really like the protagonist to spend a whole book in their head. If that relationship doesn't click, the supporting characters have a harder time salvaging the experience. Waypoint Kangaroo avoids the problem of too many loving descriptions of guns, partly because it's a spy novel and instead has loving descriptions of spy equipment in a future that supports implanted devices. I think there was a smidgen too much of this, but it was within genre conventions and spy stuff is more interesting than guns. But (and I admit that this is probably idiosyncratic), it also had way too many loving descriptions of alcohol and one drunk scene. I don't care to ever read another book with a drunk protagonist (particularly first-person), and I care considerably less about alcohol than I do about spy equipment or guns. That said, I still liked this well enough that I'll probably buy the sequel. (No cliffhangers; Waypoint Kangaroo is a complete story. But this is a character who could easily support a long episodic series.) The pocket is a neat gimmick, the world background is at least mildly interesting, and some of the supporting characters were excellent. (Particularly the security chief and the engineer.) I might even warm to Kangaroo over time if subsequent stories stay more on his creative fast-talking rather than his drinking and awkward romances. I don't think this is quite good enough for me to recommend it, but if you're in the mood for a light and fast-moving first-person Bond-style story with science fiction trappings, it does deliver. Rating: 6 out of 10

23 October 2017

Patrick Schoenfeld: Testing javascript in a dockerized rails application with rspec-rails

The other day I wanted to add support for tests of javascript functionality in a (dockerized) rails application using rspec-rails. Since rails 5.1 includes system tests with niceties like automatically taking a screenshot on failed tests, I hoped for a way to benefit from this
features without changing to another test framework. Lucky me only recently the authors of rspec-rails added support for so-called system specs. There is not much documentation so far (but there are a lot of useful information in the corresponding bug report #1838 and a friendly guy named Thomas Walpole (@twalpole) is helpfully answering to questions in that issue. To make things a little bit more complicated: the application in question is usually running in a docker container and thus the tests of the application are also run in a docker container. I didn t want to change this, so here is what it took me to get this running. Overview Let s see what we want to achieve exactly: From a technical point of view, we will have the application under test (AUT) and the tests in one container (let s call it: web) and we will need another container running a javascript-capable browser (let s call it browser). Thus we need the tests to drive a remote running browser (at least when running in a docker environment) which needs to access the application under a different address than usually. Namely an address reachable by the chrome-container, since it will not be reachable via 127.0.0.1 as is (rightfully) assumed by default. If we want Warden authentication stubbing to work (as we do, since our application uses Devise) and transactional fixtures as well (e.g. rails handling database cleanup between tests without database_cleaner gem) we also need to ensure that the application server is being started by the tests and the tests are actually run against that server. Otherwise we might run into problems. Getting the containers ready Assuming you already have a container setup (and are using docker-compose like we do) there is not that much to change on the docker front. Basically you need to add a new service called chrome and point it to an appropriate image and add a link to it in your existing web-container. I ve decided to use standalone-chrome for the browser part, for which there are docker images provided by the selenium project (they also have images for other browsers). Kudos for that.
...
services:
  chrome:
    image: selenium/standalone-chrome
   
  web:
   
    links:
      - chrome
The link ensures that the chrome instance is available before we run the tests and that the the web-container is able to resolve the name of this container. Unfortunately this is not true for the other way round, so we need some magic in our test code to find out the ip-address of the web-container. More to this later. Other than that, you probably want to configure a volume for you to be able to access the screenshots, which get saved to tmp/screenshots
in the application directory. Preparing the application for running system tests There is a bit more to do on the application side. The steps are roughly:
  1. Add necessary depends / version constraints
  2. Register a driver for the remote chrome
  3. Configure capybara to use the appropriate host for your tests (and your configured driver)
  4. Add actual tests with type: :system and js: true
Let s walk them through. Add necessary depends What we need is the following: The required features are already part of 3.7.0, but this version is the version I used and it contains a bugfix, which may or may not be relevant. One comment about the rails version: for the tests to properly work it s viable to have puma use certain settings. In rails 5.1.4 (the version released, at time of writing this) uses the settings from config/puma.rb which most likely collides with the necessary settings. You can ensure these settings yourself or use rails from branch 5-1-stable which includes this change. I decided for the latter and pinned my Gemfile to the then current commit. Register a driver for the remote chrome To register the required driver, you ll have to add some lines to your rails_helper.rb:
if ENV['DOCKER']
  selenium_url =
      "http://chrome:4444/wd/hub"
  Capybara.register_driver :selenium_remote do  app 
    Capybara::Selenium::Driver.new(app,
         :url => selenium_url, :browser => :remote, desired_capabilities: :chrome )
  end
end
Note that I added those lines conditionally (since I still want to be able to use a local chrome via chromedriver) if an environment variable DOCKER is set. We defined that environment variable in our Dockerfile and thus you might need to adapt this to your case. Also note that the selenium_url is hard-coded. You could very well take a different approach, e.g. using an externally specified SELENIUM_URL, but ultimately the requirement is that the driver needs to know that the chrome instance is running on host chrome, port 4444 (the containers default). Configure capybara to use the appropriate host and driver The next step is to ensure that javascript-requiring system tests are actually run with the given driver and use the right host. To achieve that we need to add a before-hook to the corresponding tests or we can configure rspec accordingly to always include such a hook by modifying the rspec-configuration in rails_helper.rb like this:
RSpec.configure do  config 
  ...
  config.before(:each, type: :system, js: true) do
    if ENV['DOCKER']
      driven_by :selenium_remote
      ip = Socket.ip_address_list.detect addr  addr.ipv4_private?  .ip_address
      host! "http://# ip :# Capybara.server_port "
    else
      driven_by :headless_chrome
    end
  end
Note the part with the ip-address: it tries to find an IPv4 private address for the web-container (the container running the tests) to ensure the chrome-container uses this address to access the application. The Capybara.server_port is important here, since it will correspond to the puma instance launched by the tests. That heuristic (first ipv4 private address) works for us at the moment, but it might not work for you. It is basically a workaround to the fact that I couldn t get web resolvable for the chrome container which may be fixable on the docker side, but I was to lazy to further investigate that. If you change it: Just make sure the host! method uses an URI pointing to an address of the web-container that is reachable to the chrome-container. Define tests with type: :system and js: true Last but certainly not least, you need actual tests of the required type and with or without js: true. This can be achieved by creating tests files starting like this:
RSpec.feature "Foobar", type: :system, js: true do
Since the new rspec-style system tests are based around the feature-specs which used to be around previously, the rest of the tests is exactly like it is described for feature specs. Run the tests To run the tests a commandline like the following should do: docker-compose run web rspec It won t make a big noise about running the tests against chrome, unless something fails. In that case you ll see a message telling you where the screenshot has been placed. Troubleshooting Below I add some hints about problems I ve seen during configuring that: Test failing, screenshot shows login screen In that case puma might be configured wrongly or you are not using transactional fixtures. See the hints above about the rails version to use which also includes some pointers to helpful explanations. Note that rspec-rails by default does not output the puma startup output as it clutters the tests. For debugging purposes it might be helpful to change that by adding the following line to your tests:
ActionDispatch::SystemTesting::Server.silence_puma = false
Error message: Unable to find chromedriver This indicates that your driver is not configured properly, because the default for system tests is to be driven_by selenium, which tries to spawn an own chrome instance and is suitable for non-dockerized tests. Check if your tests are marked as js: true (if you followed the instructions above) and that you properly added the before-hook to your rspec-configuration. Collisions with VCR If you happen to have tests that make use of the vcr gem you might see it complaining about not knowing what to do with the requests between the driver and the chrome instance. You can fix this, by telling VCR to ignore that requests, by adding a line where you configured VCR:
VCR.configure do  config 
# required so we don't collide with capybara tests
config.ignore_hosts 'chrome'
...

Russ Allbery: Review: Algorithms to Live By

Review: Algorithms to Live By, by Brian Christian & Tom Griffiths
Publisher: Henry Holt and Company
Copyright: April 2016
ISBN: 1-62779-037-3
Format: Kindle
Pages: 255
Another read for the work book club. This was my favorite to date, apart from the books I recommended myself. One of the foundations of computer science as a field of study is research into algorithms: how do we solve problems efficiently using computer programs? This is a largely mathematical field, but it's often less about ideal or theoretical solutions and more about making the most efficient use of limited resources and arriving at an adequate, if not perfect, answer. Many of these problems are either day-to-day human problems or are closely related to them; after all, the purpose of computer science is to solve practical problems with computers. The question asked by Algorithms to Live By is "can we reverse this?": can we learn lessons from computer science's approach to problems that would help us make day-to-day decisions? There's a lot of interesting material in the eleven chapters of this book, but there's also an amusing theme: humans are already very good at this. Many chapters start with an examination of algorithms and mathematical analysis of problems, dive into a discussion of how we can use those results to make better decisions, then talk about studies of the decisions humans actually make... and discover that humans are already applying ad hoc versions of the best algorithms we've come up with, given the constraints of typical life situations. It tends to undermine the stated goal of the book. Thankfully, it in no way undermines interesting discussion of general classes of problems, how computer science has tackled them, and what we've learned about the mathematical and technical shapes of those problems. There's a bit less self-help utility here than I think the authors had intended, but lots of food for thought. (That said, it's worth considering whether this congruence is less because humans are already good at this and more because our algorithms are designed from human intuition. Maybe our best algorithms just reflect human thinking. In some cases we've checked our solutions against mathematical ideals, but in other cases they're still just our best guesses to date.) This is the sort of a book where a chapter listing is an important part of the review. The areas of algorithms discussed here are optimal stopping, explore/exploit decisions (when to go with the best thing you've found and when to look for something better), sorting, caching, scheduling, Bayes's rule (and prediction in general), overfitting when building models, relaxation (solving an easier problem than your actual problem), randomized algorithms, a collection of networking algorithms, and finally game theory. Each of these has useful insights and thought-provoking discussion of how these sometimes-theoretical concepts map surprisingly well onto daily problems. The book concludes with a discussion of "computational kindness": an encouragement to reduce the required computation and complexity penalty for both yourself and the people you interact with. If you have a computer science background (as I do), many of these will be familiar concepts, and you might be dubious that a popularization would tell you much that's new. Give this book a shot, though; the analogies are less stretched than you might fear, and the authors are both careful and smart about how they apply these principles. This book passes with flying colors a key sanity check: the chapters on topics that I know well or have thought about a lot make few or no obvious errors and say useful and important things. For example, the scheduling chapter, which unsurprisingly is about time management, surpasses more than half of the time management literature by jumping straight to the heart of most time management problems: if you're going to do everything on a list, it rarely matters the order in which you do it, so the hardest scheduling problems are about deciding what not to do rather than deciding order. The point in the book where the authors won my heart completely was in the chapter on Bayes's rule. Much of the chapter is about Bayesian priors, and how one's knowledge of past events is a vital part of analysis of future probabilities. The authors then discuss the (in)famous marshmallow experiment, in which children are given one marshmallow and told that if they refrain from eating it until the researcher returns, they'll get two marshmallows. Refraining from eating the marshmallow (delayed gratification, in the psychological literature) was found to be associated with better life outcomes years down the road. This experiment has been used and abused for years for all sorts of propaganda about how trading immediate pleasure for future gains leads to a successful life, and how failure in life is because of inability to delay gratification. More evil analyses have (of course) tied that capability to ethnicity, with predictably racist results. I have kind of a thing about the marshmallow experiment. It's a topic that reliably sends me off into angry rants. Algorithms to Live By is the only book I have ever read to mention the marshmallow experiment and then apply the analysis that I find far more convincing. This is not a test of innate capability in the children; it's a test of their Bayesian priors. When does it make perfect sense to eat the marshmallow immediately instead of waiting for a reward? When their past experience tells them that adults are unreliable, can't be trusted, disappear for unpredictable lengths of time, and lie. And, even better, the authors supported this analysis with both a follow-up study I hadn't heard of before and with the observation that some children would wait for some time and then "give in." This makes perfect sense if they were subconsciously using a Bayesian model with poor priors. This is a great book. It may try a bit too hard in places (applicability of the math of optimal stopping to everyday life is more contingent and strained than I think the authors want to admit), and some of this will be familiar if you've studied algorithms. But the writing is clear, succinct, and very well-edited. No part of the book outlives its welcome; the discussion moves right along. If you find yourself going "I know all this already," you'll still probably encounter a new concept or neat explanation in a few more pages. And sometimes the authors make connections that never would have occurred to me but feel right in retrospect, such as relating exponential backoff in networking protocols to choosing punishments in the criminal justice system. Or the realization that our modern communication world is not constantly connected, it's constantly buffered, and many of us are suffering from the characteristic signs of buffer bloat. I don't think you have to be a CS major, or know much about math, to read this book. There is a lot of mathematical details in the end notes if you want to dive in, but the main text is almost always readable and clear, at least so far as I could tell (as someone who was a CS major and has taken a lot of math, so a grain of salt may be indicated). And it still has a lot to offer even if you've studied algorithms for years. The more I read of this book, the more I liked it. Definitely recommended if you like reading this sort of analysis of life. Rating: 9 out of 10

Julian Andres Klode: APT 1.6 alpha 1 seccomp and more

I just uploaded APT 1.6 alpha 1, introducing a very scary thing: Seccomp sandboxing for methods, the programs downloading files from the internet and decompressing or compressing stuff. With seccomp I reduced the number of system calls these methods can use to 149 from 430. Specifically we excluded most ways of IPC, xattrs, and most importantly, the ability for methods to clone(2), fork(2), or execve(2) (or execveat(2)). Yes, that s right methods can no longer execute programs. This was a real problem, because the http method did in fact execute programs there is this small option called ProxyAutoDetect or Proxy-Auto-Detect where you can specify a script to run for an URL and the script outputs a (list of) proxies. In order to be able to seccomp the http method, I moved the invocation of the script to the parent process. The parent process now executes the script within the sandbox user, but without seccomp (obviously). I tested the code on amd64, ppc64el, s390x, arm64, mipsel, i386, and armhf. I hope it works on all other architectures libseccomp is currently built for in Debian, but I did not check that, so your apt might be broken now if you use powerpc, powerpcspe, armel, mips, mips64el, hhpa, or x32 (I don t think you can even really use x32). Also, apt-transport-https is gone for good now. When installing the new apt release, any installed apt-transport-https package is removed (apt breaks apt-transport-https now, but it also provides it versioned, so any dependencies should still be satisfiable). David also did a few cool bug fixes again, finally teaching apt-key to ignore unsupported GPG key files instead of causing weird errors
Filed under: Uncategorized

18 October 2017

Joey Hess: extending Scuttlebutt with Annah

This post has it all. Flotillas of sailboats, peer-to-peer wikis, games, and de-frogging. But, I need to start by talking about some tech you may not have heard of yet... So, how could these be combined together, and what might the result look like? Well, I could start by posting a Scuttlebutt message that defines what True is. And another Scuttlebutt message defining False. And then, another Scuttlebutt message to define the AND function, which would link to my messages for True and False. Continue this until I've built up enough Annah code to write some almost useful programs. Annah can't do any IO on its own (though it can model IO similarly to how Haskell does), so for programs to be actually useful, there needs to be Scuttlebutt client support. The way typing works in Annah, a program's type can be expressed as a Scuttlebutt link. So a Scuttlebutt client that wants to run Annah programs of a particular type can pick out programs that link to that type, and will know what type of data the program consumes and produces. Here are a few ideas of what could be built, with fairly simple client-side support for different types of Annah programs... This kind of extensibility in a peer-to-peer system is exciting! With these new systems, we can consider lessons from the world wide web and replicate some of the good parts, while avoiding the bad. Javascript has been both good and bad for the web. The extensibility is great, and yet it's a neverending security and privacy nightmare, and it ties web pages ever more tightly to programs hidden away on servers. I believe that Annah combined with Scuttlebutt will comprehensively avoid those problems. Shall we build it?
This exploration was sponsored by Jake Vosloo on Patreon.

17 October 2017

Russ Allbery: Bundle haul

Confession time: I started making these posts (eons ago) because a close friend did as well, and I enjoyed reading them. But the main reason why I continue is because the primary way I have to keep track of the books I've bought and avoid duplicates is, well, grep on these posts. I should come up with a non-bullshit way of doing this, but time to do more elegant things is in short supply, and, well, it's my blog. So I'm boring all of you who read this in various places with my internal bookkeeping. I do try to at least add a bit of commentary. This one will be more tedious than most since it includes five separate Humble Bundles, which increases the volume a lot. (I just realized I'd forgotten to record those purchases from the past several months.) First, the individual books I bought directly: Ilona Andrews Sweep in Peace (sff)
Ilona Andrews One Fell Sweep (sff)
Steven Brust Vallista (sff)
Nicky Drayden The Prey of Gods (sff)
Meg Elison The Book of the Unnamed Midwife (sff)
Pat Green Night Moves (nonfiction)
Ann Leckie Provenance (sff)
Seanan McGuire Once Broken Faith (sff)
Seanan McGuire The Brightest Fell (sff)
K. Arsenault Rivera The Tiger's Daughter (sff)
Matthew Walker Why We Sleep (nonfiction)
Some new books by favorite authors, a few new releases I heard good things about, and two (Night Moves and Why We Sleep) from references in on-line articles that impressed me. The books from security bundles (this is mostly work reading, assuming I'll get to any of it), including a blockchain bundle: Wil Allsop Unauthorised Access (nonfiction)
Ross Anderson Security Engineering (nonfiction)
Chris Anley, et al. The Shellcoder's Handbook (nonfiction)
Conrad Barsky & Chris Wilmer Bitcoin for the Befuddled (nonfiction)
Imran Bashir Mastering Blockchain (nonfiction)
Richard Bejtlich The Practice of Network Security (nonfiction)
Kariappa Bheemaiah The Blockchain Alternative (nonfiction)
Violet Blue Smart Girl's Guide to Privacy (nonfiction)
Richard Caetano Learning Bitcoin (nonfiction)
Nick Cano Game Hacking (nonfiction)
Bruce Dang, et al. Practical Reverse Engineering (nonfiction)
Chris Dannen Introducing Ethereum and Solidity (nonfiction)
Daniel Drescher Blockchain Basics (nonfiction)
Chris Eagle The IDA Pro Book, 2nd Edition (nonfiction)
Nikolay Elenkov Android Security Internals (nonfiction)
Jon Erickson Hacking, 2nd Edition (nonfiction)
Pedro Franco Understanding Bitcoin (nonfiction)
Christopher Hadnagy Social Engineering (nonfiction)
Peter N.M. Hansteen The Book of PF (nonfiction)
Brian Kelly The Bitcoin Big Bang (nonfiction)
David Kennedy, et al. Metasploit (nonfiction)
Manul Laphroaig (ed.) PoC GTFO (nonfiction)
Michael Hale Ligh, et al. The Art of Memory Forensics (nonfiction)
Michael Hale Ligh, et al. Malware Analyst's Cookbook (nonfiction)
Michael W. Lucas Absolute OpenBSD, 2nd Edition (nonfiction)
Bruce Nikkel Practical Forensic Imaging (nonfiction)
Sean-Philip Oriyano CEHv9 (nonfiction)
Kevin D. Mitnick The Art of Deception (nonfiction)
Narayan Prusty Building Blockchain Projects (nonfiction)
Prypto Bitcoin for Dummies (nonfiction)
Chris Sanders Practical Packet Analysis, 3rd Edition (nonfiction)
Bruce Schneier Applied Cryptography (nonfiction)
Adam Shostack Threat Modeling (nonfiction)
Craig Smith The Car Hacker's Handbook (nonfiction)
Dafydd Stuttard & Marcus Pinto The Web Application Hacker's Handbook (nonfiction)
Albert Szmigielski Bitcoin Essentials (nonfiction)
David Thiel iOS Application Security (nonfiction)
Georgia Weidman Penetration Testing (nonfiction)
Finally, the two SF bundles: Buzz Aldrin & John Barnes Encounter with Tiber (sff)
Poul Anderson Orion Shall Rise (sff)
Greg Bear The Forge of God (sff)
Octavia E. Butler Dawn (sff)
William C. Dietz Steelheart (sff)
J.L. Doty A Choice of Treasons (sff)
Harlan Ellison The City on the Edge of Forever (sff)
Toh Enjoe Self-Reference ENGINE (sff)
David Feintuch Midshipman's Hope (sff)
Alan Dean Foster Icerigger (sff)
Alan Dean Foster Mission to Moulokin (sff)
Alan Dean Foster The Deluge Drivers (sff)
Taiyo Fujii Orbital Cloud (sff)
Hideo Furukawa Belka, Why Don't You Bark? (sff)
Haikasoru (ed.) Saiensu Fikushon 2016 (sff anthology)
Joe Haldeman All My Sins Remembered (sff)
Jyouji Hayashi The Ouroboros Wave (sff)
Sergei Lukyanenko The Genome (sff)
Chohei Kambayashi Good Luck, Yukikaze (sff)
Chohei Kambayashi Yukikaze (sff)
Sakyo Komatsu Virus (sff)
Miyuki Miyabe The Book of Heroes (sff)
Kazuki Sakuraba Red Girls (sff)
Robert Silverberg Across a Billion Years (sff)
Allen Steele Orbital Decay (sff)
Bruce Sterling Schismatrix Plus (sff)
Michael Swanwick Vacuum Flowers (sff)
Yoshiki Tanaka Legend of the Galactic Heroes, Volume 1: Dawn (sff)
Yoshiki Tanaka Legend of the Galactic Heroes, Volume 2: Ambition (sff)
Yoshiki Tanaka Legend of the Galactic Heroes, Volume 3: Endurance (sff)
Tow Ubukata Mardock Scramble (sff)
Sayuri Ueda The Cage of Zeus (sff)
Sean Williams & Shane Dix Echoes of Earth (sff)
Hiroshi Yamamoto MM9 (sff)
Timothy Zahn Blackcollar (sff)
Phew. Okay, all caught up, and hopefully won't have to dump something like this again in the near future. Also, more books than I have any actual time to read, but what else is new.

Norbert Preining: Japanese TeX User Meeting 2017

Last saturday the Japanese TeX User Meeting took place in Fujisawa, Kanagawa. For those who have been at the TUG 2013 in Tokyo you will remember that the Japanese TeX community is quite big and vibrant. On Saturday about 50 users and developers gathered for a set of talks on a variety of topics. The first talk was by Keiichiro Shikano ( ) on using Markup text to generate (La)TeX and HTML. He presented a variety of markup formats, including his own tool xml2tex. The second talk was my Masamichi Hosoda ( ) on reducing the size of PDF files using PDFmark extraction. As a contributor to many projects including Texinfo and LilyPond, Masamichi Hosoda tells us horror stories about multiple font embedding in the manual of LilyPond, the permanent need for adaption to newer Ghostscript versions, and the very recent development in Ghostscript prohibiting the merge of font definitions in PDF files. Next up was Yusuke Terada ( ) on grading exams using TeX. Working through hundreds and hundreds of exams and do the grading is something many of us are used to and I think nobody really enjoys it. Yusuke Terada has combined various tools, including scans, pdf merging using pdfpages, to generate gradable PDF which were then checked on an iPad. On the way he did hit some limits in dvipdfmx on the number of images, but this was obviously only a small bump on the road. Now if that could be automatized as a nice application, it would be a big hit I guess! The forth talk was by Satoshi Yamashita ( ) on the preparation of slides using KETpic. KETpic is a long running project by Setsuo Takato ( ) for the generation of graphics, in particular using Cinderella. KETpic and KETcindy integrates with lots of algebraic and statistical programs (R, Maxima, SciLab, ) and has a long history of development. Currently there are activities to incorporate it into TeX Live. The fifth talk was by Takuto Asakura ( ) on programming TeX using expl3, the main building block of the LaTeX3 project and already adopted by many TeX developers. Takuto Asakura came to fame on this years TUG/BachoTeX 2017 when he won the W. J. Martin Prize for his presentation Implementing bioinformatics algorithms in TeX. I think we can expect great new developments from Takuto! The last talk was by myself on fmtutil and updmap, two of the main management programs in any TeX installation, presenting the changes introduced over the last year, including the most recent release of TeX Live. Details have been posted on my blog, and a lengthy article in TUGboat 38:2, 2017 is available on this topic, too. After the conference about half of the participants joined a social dinner in a nearby Izakaya, followed by a after-dinner beer tasting at a local craft beer place. Thanks to Tatsuyoshi Hamada for the organization. As usual, the Japanese TeX User Meetings are a great opportunity to discuss new features and make new friends. I am always grateful to be part of this very nice community! I am looking forward to the next year s meeting.

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.

16 October 2017

Gustavo Noronha Silva: Who knew we still had low-hanging fruits?

Earlier this month I had the pleasure of attending the Web Engines Hackfest, hosted by Igalia at their offices in A Coru a, and also sponsored by my employer, Collabora, Google and Mozilla. It has grown a lot and we had many new people this year. Fun fact: I am one of the 3 or 4 people who have attended all of the editions of the hackfest since its inception in 2009, when it was called WebKitGTK+ hackfest \o/ 20171002_204405 It was a great get together where I met many friends and made some new ones. Had plenty of discussions, mainly with Antonio Gomes and Google s Robert Kroeger, about the way forward for Chromium on Wayland. We had the opportunity of explaining how we at Collabora cooperated with igalians to implemented and optimise a Wayland nested compositor for WebKit2 to share buffers between processes in an efficient way even on broken drivers. Most of the discussions and some of the work that led to this was done in previous hackfests, by the way! 20171002_193518 The idea seems to have been mostly welcomed, the only concern being that Wayland s interfaces would need to be tested for security (fuzzed). So we may end up going that same route with Chromium for allowing process separation between the UI and GPU (being renamed Viz, currently) processes. On another note, and going back to the title of the post, at Collabora we have recently adopted Mattermost to replace our internal IRC server. Many Collaborans have decided to use Mattermost through an Epiphany Web Application or through a simple Python application that just shows a GTK+ window wrapping a WebKitGTK+ WebView. 20171002_101952 Some people noticed that when the connection was lost Mattermost would take a very long time to notice and reconnect its web sockets were taking a long, long time to timeout, according to our colleague Andrew Shadura. I did some quick searching on the codebase and noticed WebCore has a NetworkStateNotifier interface that it uses to get notified when connection changes. That was not implemented for WebKitGTK+, so it was likely what caused stuff to linger when a connection hiccup happened. Given we have GNetworkMonitor, implementation of the missing interfaces required only 3 lines of actual code (plus the necessary boilerplate)! screenshot-from-2017-10-16-11-13-39 I was surprised to still find such as low hanging fruit in WebKitGTK+, so I decided to look for more. Turns out WebCore also has a notifier for low power situations, which was implemented only by the iOS port, and causes the engine to throttle some timers and avoid some expensive checks it would do in normal situations. This required a few more lines to implement using upower-glib, but not that many either! That was the fun I had during the hackfest in terms of coding. Mostly I had fun just lurking in break out sessions discussing the past, present and future of tech such as WebRTC, Servo, Rust, WebKit, Chromium, WebVR, and more. I also beat a few challengers in Street Fighter 2, as usual. I d like to say thanks to Collabora, Igalia, Google, and Mozilla for sponsoring and attending the hackfest. Thanks to Igalia for hosting and to Collabora for sponsoring my attendance along with two other Collaborans. It was a great hackfest and I m looking forward to the next one! See you in 2018 =)

13 October 2017

Alex Muntada: My Free Software Activities in Jul-Sep 2017

If you read Planet Debian often, you ve probably noticed a trend of Free Software activity reports at the beginning of the month. First, those reports seemed a bit unamusing and lengthy, but since I take the time to read them I ve learnt a lot of things, and now I m amazed at the amount of work that people are doing for Free Software. Indeed, I knew already that many people are doing lots of work. But reading those reports gives you an actual view of how much it is. Then, I decided that I should do the same and write some kind of report since I became a Debian Developer in July. I think it s a nice way to share your work with others and maybe inspire them as it happened to me. So I asked some of the people that have been inspiring me how do they do it. I mean, I was curious to know how they keep track of the work they do and how long it takes to write their reports. It seems that it takes quite some time, it s mostly manual work and usually starts by the end of the month, reviewing their contributions in mailing lists, bug trackers, e-mail folders, etc. Here I am now, writing my first report about my Free Software activities since July and until September 2017. I hope you like it: Happy hacking!

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