Search Results: "wart"

22 February 2017

Antoine Beaupr : The case against password hashers

In previous articles, we have looked at how to generate passwords and did a review of various password managers. There is, however, a third way of managing passwords other than remembering them or encrypting them in a "vault", which is what I call "password hashing". A password hasher generates site-specific passwords from a single master password using a cryptographic hash function. It thus allows a user to have a unique and secure password for every site they use while requiring no storage; they need only to remember a single password. You may know these as "deterministic or stateless password managers" but I find the "password manager" phrase to be confusing because a hasher doesn't actually store any passwords. I do not think password hashers represent a good security tradeoff so I generally do not recommend their use, unless you really do not have access to reliable storage that you can access readily. In this article, I use the word "password" for a random string used to unlock things, but "token" to represent a generated random string that the user doesn't need to remember. The input to a password hasher is a password with some site-specific context and the output from a password hasher is a token.

What is a password hasher? A password hasher uses the master password and a label (generally the host name) to generate the site-specific password. To change the generated password, the user can modify the label, for example by appending a number. Some password hashers also have different settings to generate tokens of different lengths or compositions (symbols or not, etc.) to accommodate different site-specific password policies. The whole concept of password hashers relies on the concept of one-way cryptographic hash functions or key derivation functions that take an arbitrary input string (say a password) and generate a unique token, from which it is impossible to guess the original input string. Password hashers are generally written as JavaScript bookmarklets or browser plugins and have been around for over a decade. The biggest advantage of password hashers is that you only need to remember a single password. You do not need to carry around a password manager vault: there's no "state" (other than site-specific settings, which can be easily guessed). A password hasher named Master Password makes a compelling case against traditional password managers in its documentation:
It's as though the implicit assumptions are that everybody backs all of their stuff up to at least two different devices and backups in the cloud in at least two separate countries. Well, people don't always have perfect backups. In fact, they usually don't have any.
It goes on to argue that, when you lose your password: "You lose everything. You lose your own identity." The stateless nature of password hashers also means you do not need to use cloud services to synchronize your passwords, as there is (generally, more on that later) no state to carry around. This means, for example, that the list of accounts that you have access to is only stored in your head, and not in some online database that could be hacked without your knowledge. The downside of this is, of course, that attackers do not actually need to have access to your password hasher to start cracking it: they can try to guess your master key without ever stealing anything from you other than a single token you used to log into some random web site. Password hashers also necessarily generate unique passwords for every site you use them on. While you can also do this with password managers, it is not an enforced decision. With hashers, you get distinct and strong passwords for every site with no effort.

The problem with password hashers If hashers are so great, why would you use a password manager? Programs like LessPass and Master Password seem to have strong crypto that is well implemented, so why isn't everyone using those tools? Password hashing, as a general concept, actually has serious problems: since the hashing outputs are constantly compromised (they are sent in password forms to various possibly hostile sites), it's theoretically possible to derive the master password and then break all the generated tokens in one shot. The use of stronger key derivation functions (like PBKDF2, scrypt, or HMAC) or seeds (like a profile-specific secret) makes those attacks much harder, especially if the seed is long enough to make brute-force attacks infeasible. (Unfortunately, in the case of Password Hasher Plus, the seed is derived from Math.random() calls, which are not considered cryptographically secure.) Basically, as stated by Julian Morrison in this discussion:
A password is now ciphertext, not a block of line noise. Every time you transmit it, you are giving away potential clues of use to an attacker. [...] You only have one password for all the sites, really, underneath, and it's your secret key. If it's broken, it's now a skeleton-key [...]
Newer implementations like LessPass and Master Password fix this by using reasonable key derivation algorithms (PBKDF2 and scrypt, respectively) that are more resistant to offline cracking attacks, but who knows how long those will hold? To give a concrete example, if you would like to use the new winner of the password hashing competition (Argon2) in your password manager, you can patch the program (or wait for an update) and re-encrypt your database. With a password hasher, it's not so easy: changing the algorithm means logging in to every site you visited and changing the password. As someone who used a password hasher for a few years, I can tell you this is really impractical: you quickly end up with hundreds of passwords. The LessPass developers tried to facilitate this, but they ended up mostly giving up. Which brings us to the question of state. A lot of those tools claim to work "without a server" or as being "stateless" and while those claims are partly true, hashers are way more usable (and more secure, with profile secrets) when they do keep some sort of state. For example, Password Hasher Plus records, in your browser profile, which site you visited and which settings were used on each site, which makes it easier to comply with weird password policies. But then that state needs to be backed up and synchronized across multiple devices, which led LessPass to offer a service (which you can also self-host) to keep those settings online. At this point, a key benefit of the password hasher approach (not keeping state) just disappears and you might as well use a password manager. Another issue with password hashers is choosing the right one from the start, because changing software generally means changing the algorithm, and therefore changing passwords everywhere. If there was a well-established program that was be recognized as a solid cryptographic solution by the community, I would feel more confident. But what I have seen is that there are a lot of different implementations each with its own warts and flaws; because changing is so painful, I can't actually use any of those alternatives. All of the password hashers I have reviewed have severe security versus usability tradeoffs. For example, LessPass has what seems to be a sound cryptographic implementation, but using it requires you to click on the icon, fill in the fields, click generate, and then copy the password into the field, which means at least four or five actions per password. The venerable Password Hasher is much easier to use, but it makes you type the master password directly in the site's password form, so hostile sites can simply use JavaScript to sniff the master password while it is typed. While there are workarounds implemented in Password Hasher Plus (the profile-specific secret), both tools are more or less abandoned now. The Password Hasher homepage, linked from the extension page, is now a 404. Password Hasher Plus hasn't seen a release in over a year and there is no space for collaborating on the software the homepage is simply the author's Google+ page with no information on the project. I couldn't actually find the source online and had to download the Chrome extension by hand to review the source code. Software abandonment is a serious issue for every project out there, but I would argue that it is especially severe for password hashers. Furthermore, I have had difficulty using password hashers in unified login environments like Wikipedia's or StackExchange's single-sign-on systems. Because they allow you to log in with the same password on multiple sites, you need to choose (and remember) what label you used when signing in. Did I sign in on stackoverflow.com? Or was it stackexchange.com? Also, as mentioned in the previous article about password managers, web-based password managers have serious security flaws. Since more than a few password hashers are implemented using bookmarklets, they bring all of those serious vulnerabilities with them, which can range from account name to master password disclosures. Finally, some of the password hashers use dubious crypto primitives that were valid and interesting a decade ago, but are really showing their age now. Stanford's pwdhash uses MD5, which is considered "cryptographically broken and unsuitable for further use". We have seen partial key recovery attacks against MD5 already and while those do not allow an attacker to recover the full master password yet (especially not with HMAC-MD5), I would not recommend anyone use MD5 in anything at this point, especially if changing that algorithm later is hard. Some hashers (like Password Hasher and Password Plus) use a a single round of SHA-1 to derive a token from a password; WPA2 (standardized in 2004) uses 4096 iterations of HMAC-SHA1. A recent US National Institute of Standards and Technology (NIST) report also recommends "at least 10,000 iterations of the hash function".

Conclusion Forced to suggest a password hasher, I would probably point to LessPass or Master Password, depending on the platform of the person asking. But, for now, I have determined that the security drawbacks of password hashers are not acceptable and I do not recommend them. It makes my password management recommendation shorter anyway: "remember a few carefully generated passwords and shove everything else in a password manager". [Many thanks to Daniel Kahn Gillmor for the thorough reviews provided for the password articles.]
Note: this article first appeared in the Linux Weekly News. Also, details of my research into password hashers are available in the password hashers history article.

31 December 2016

Jonathan McDowell: IMDB Top 250: Complete. Sort of.

Back in 2010, inspired by Juliet, I set about doing 101 things in 1001 days. I had various levels of success, but one of the things I did complete was the aim of watching half of the IMDB Top 250. I didn t stop at that point, but continued to work through it at a much slower pace until I realised that through the Queen s library I had access to quite a few DVDs of things I was missing, and that it was perfectly possible to complete the list by the end of 2016. So I did. I should point out that I didn t set out to watch the list because I m some massive film buff. It was more a mixture of watching things that I wouldn t otherwise choose to, and also watching things I knew were providing cultural underpinnings to films I had already watched and enjoyed. That said, people have asked for some sort of write up when I was done. So here are some random observations, which are almost certainly not what they were looking for.

My favourite film is not in the Top 250 First question anyone asks is What s your favourite film? . That depends a lot on what I m in the mood for really, but fairly consistently my answer is The Hunt for Red October. This has never been in the Top 250 that I ve noticed. Which either says a lot about my taste in films, or the Top 250, or both. Das Boot was in the list and I would highly recommend it (but then I like all submarine movies it seems).

The Shawshank Redemption is overrated I can t recall a time when The Shawshank Redemption was not top of the list. It s a good film, and I ve watched it many times, but I don t think it s good enough to justify its seemingly unbroken run. I don t have a suggestion for a replacement, however.

The list is constantly changing I say I ve completed the Top 250, but that s working from a snapshot I took back in 2010. Today the site is telling me I ve watched 215 of the current list. Last night it was 214 and I haven t watched anything in between. Some of those are films released since 2010 (in particular new releases often enter high and then fall out of the list over a month or two), but the current list has films as old as 1928 (The Passion of Joan of Arc) that weren t there back in 2010. So keeping up to date is not simply a matter of watching new releases.

The best way to watch the list is terrestrial TV There were various methods I used to watch the list. Some I d seen in the cinema when they came out (or was able to catch that way anyway - the QFT showed Duck Soup, for example). Netflix and Amazon Video had some films, but overall a very disappointing percentage. The QUB Library, as previously mentioned, had a good number of DVDs on the list (especially the older things). I ended up buying a few (Dial M for Murder on 3D Bluray was well worth it; it s beautifully shot and unobtrusively 3D), borrowed a few from friends and ended up finishing off the list by a Lovefilm one month free trial. The single best source, however, was UK terrestrial TV. Over the past 6 years Freeview (the free-to-air service here) had the highest percentage of the list available. Of course this requires some degree of organisation to make sure you don t miss things.

Films I enjoyed Not necessarily my favourite, but things I wouldn t have necessarily watched and was pleasantly surprised by. No particular order, and I m leaving out a lot of films I really enjoyed but would have got around to watching anyway.
  • Clint Eastwood films - Gran Torino and Million Dollar Baby were both excellent but neither would have appealed to me at first glance. I hated Unforgiven though.
  • Jimmy Stewart. I m not a fan of It s a Wonderful Life (which I d already watched because it s Lister s favourite film), but Harvey is obviously the basis of lots of imaginary friend movies and Rear Window explained a Simpsons episode (there were a lot of Simpsons episodes explained by watching the list).
  • Spaghetti Westerns. I wouldn t have thought they were my thing, but I really enjoyed the Sergio Leone films (A Fistful of Dollars etc.). You can see where Tarantino gets a lot of his inspiration.
  • Foreign language films. I wouldn t normally seek these out. And in general it seems I cannot get on with Italian films (except Life is Beautiful), but Amores Perros, Amelie and Ikiru were all better than expected.
  • Kind Hearts and Coronets. For some reason I didn t watch this until almost the end; I think the title always put me off. Turned out to be very enjoyable.

Films I didn t enjoy I m sure these mark me out as not being a film buff, but there are various things I would have turned off if I d caught them by accident rather than setting out to watch them. I ve kept the full list available, if you re curious.

30 December 2016

Chris Lamb: My favourite books of 2016

Whilst I managed to read almost sixty books in 2016 here are ten of my favourites in no particular order. Disappointments this year include Stewart Lee's Content Provider (nothing like his stand-up), Christopher Hitchens' And Yet (his best essays are already published) and Heinlein's Stranger in a Strange Land (great exposition, bizarre conclusion). The worst book I finished, by far, was Mark Edward's Follow You Home.





https://images-eu.ssl-images-amazon.com/images/P/B010EAQLV2.01._PC__.jpg Animal QC Gary Bell, QC Subtitled My Preposterous Life, this rags-to-riches story about a working-class boy turned eminent lawyer would be highly readable as a dry and factual account but I am compelled to include it here for its extremely entertaining style of writing. Full of unsurprising quotes that take one unaware: would you really expect a now-Queen's Counsel to "heartily suggest that if you find yourself suffering from dysentery in foreign climes you do not medicate it with lobster thermidor and a bottle of Ecuadorian red?" A real good yarn.
https://images-eu.ssl-images-amazon.com/images/P/B0196HJ6OS.01._PC__.jpg So You've Been Publically Shamed Jon Ronson The author was initially recommended to me by Brad but I believe I started out with the wrong book. In fact, I even had my doubts about this one, prematurely judging from the title that it was merely cashing-in on a fairly recent internet phenomenon like his more recent shallow take on Trump and the alt-Right but in the end I read Publically Shamed thrice in quick succession. I would particularly endorse the audiobook version: Ronson's deadpan drawl suits his writing perfectly.
https://images-eu.ssl-images-amazon.com/images/P/B00IX49OS4.01._PC__.jpg The Obstacle is the Way Ryan Holiday Whilst everyone else appears to be obligated to include Ryan's recent Ego is the Enemy in their Best of 2016 lists I was actually taken by his earlier "introduction by stealth" to stoic philosophy. Certainly not your typical self-help book, this is "a manual to turn to in troubling times". Returning to this work at least three times over the year even splashing out on the audiobook at some point I feel like I learned a great deal, although it is now difficult to pinpoint exactly what. Perhaps another read in 2017 is thus in order
https://images-eu.ssl-images-amazon.com/images/P/071563335X.01._PC__.jpg Layer Cake J.J. Connolly To judge a book in comparison to the film is to do both a disservice, but reading the book of Layer Cake really underscored just how well the film played to the strengths of that medium. All of the aspects that would not have worked had been carefully excised from the screenplay, ironically leaving more rewarding "layers" for readers attempting the book. A parallel adaption here might be No Country for Old Men - I would love to read (or write) a comparative essay between these two adaptions although McCarthy's novel is certainly the superior source material.
https://images-eu.ssl-images-amazon.com/images/P/B00G1SRB6Q.01._PC__.jpg Lying Sam Harris I've absorbed a lot of Sam Harris's uvre this year in the form of his books but moreover via his compelling podcast. I'm especially fond of Waking Up on spirituality without religion and would rank that as my favourite work of his. Lying is a comparatively short read, more of a long essay in fact, where he argues that we can radically simplify our lives by merely telling the truth in situations where others invariably lie. Whilst it would take a brave soul to adopt his approach his case is superlatively well-argued and a delight to read.
https://images-eu.ssl-images-amazon.com/images/P/0140442103.01._PC__.jpg Letters from a Stoic Seneca

Great pleasure is to be found not only in keeping up an old and established friendship but also in beginning and building up a new one. Reading this in a beautifully svelte hardback, I tackled a randomly-chosen letter per day rather than attempting to read it cover-to-cover. Breaking with a life-long tradition, I even decided to highlight sections in pen so I could return to them at ease. I hope it's not too hackneyed to claim I gained a lot from "building up" a relationship with this book. Alas, it is one of those books that is too easy to recommend given that it might make one appear wise and learned, but if you find yourself in a slump, either in life or in your reading habits, it certainly has my approval.


https://images-eu.ssl-images-amazon.com/images/P/B00BHD3TIE.01._PC__.jpg Solo: A James Bond Novel William Boyd I must have read all of the canonical Fleming novels as a teenager and Solo really rewards anyone who has done so. It would certainly punish anyone expecting a Goldeneye or at least be a little too foreign to be enjoyed. Indeed, its really a pastiche of these originals, both in terms of the time period, general tone (Bond is more somber; more vulnerable) and in various obsessions of Fleming's writing, such as the overly-detailed description of the gambling and dining tables. In this universe, 007's restaurant expenses probably contributed signifcantly to the downfall of the British Empire, let alone his waistline. Bond flicking through a ornithological book at one point was a cute touch
https://images-eu.ssl-images-amazon.com/images/P/B019MMUA8S.01._PC__.jpg The Subtle Art of Not Giving A F*ck Mark Manson Certainly a wildcard to include here and not without its problems, The Subtle Art is a curious manifesto on how to approach life. Whilst Manson expouses an age-old philosophy of grounding yourself and ignoring the accumulation of flatscreen TVs, etc. he manages to do so in a fresh and provocative "21st-centry gonzo" style. Highly entertaining, at one point the author posits an alternative superhero ("Disappointment Panda") that dishes out unsolicited and uncomfortable truths to strangers before simply walking away: "You know, if you make more money, that s not going to make your kids love you," or: "What you consider friendship is really just your constant attempts to impress people." Ouch.
https://images-eu.ssl-images-amazon.com/images/P/B004ZLS5RK.01._PC__.jpg The Fourth Protocol Frederick Forsyth I have a crystal-clear memory from my childhood of watching a single scene from a film in the dead of night: Pierce Brosnan sets a nuclear device to detonate after he can get away but a double-crossing accomplice surreptitiously brings the timetable forward in order that the bomb also disposes of him Anyway, at some point whilst reading The Fourth Protocol it dawned on me that this was that book. I might thus be giving the book more credit due to this highly satisfying connection but I think it stands alone as a superlative political page-turner and is still approachable outside the machinations of the Cold War.
https://images-eu.ssl-images-amazon.com/images/P/B003IDMUSG.01._PC__.jpg The Partner John Grisham After indulging in a bit too much non-fiction and an aborted attempt at The Ministry of Fear, I turned to a few so-called lower-brow writers such as Jeffrey Archer, etc. However, it was The Partner that turned out to be a real page-turner for somewhat undefinable reasons. Alas, it appears the rest of the author's output is unfortunately in the same vein (laywers, etc.) so I am hesitant to immediately begin others but judging from various lists online I am glad I approached this one first.
https://images-eu.ssl-images-amazon.com/images/P/B00D3J2QKC.01._PC__.jpg Shogun: The First Novel of the Asian saga James Clavell Despite its length, I simply couldn't resist returning to Shogun this year although it did fatigue me to the point that I have still yet to commence on its sequel, Tai-Pan. Like any good musical composition, one is always rewarded by returning to a book and I took great delight in uncovering more symbolism throughout (such as noticing that one of the first words Blackthorne learns in Japanese is "truth") but also really savouring the tragic arcs that run throughout the novel, some beautiful phrases ("The day seemed to lose its warmth ") and its wistful themes of inevitability and karma.

3 November 2016

Simon Josefsson: Why I don t Use 2048 or 4096 RSA Key Sizes

I have used non-standard RSA key size for maybe 15 years. For example, my old OpenPGP key created in 2002. With non-standard key sizes, I mean a RSA key size that is not 2048 or 4096. I do this when I generate OpenPGP/SSH keys (using GnuPG with a smartcard like this) and PKIX certificates (using GnuTLS or OpenSSL, e.g. for XMPP or for HTTPS). People sometimes ask me why. I haven t seen anyone talk about this, or provide a writeup, that is consistent with my views. So I wanted to write about my motivation, so that it is easy for me to refer to, and hopefully to inspire others to think similarily. Or to provoke discussion and disagreement that s fine, and hopefully I will learn something. Before proceeding, here is some context: When building new things, it is usually better to use the Elliptic Curve technology algorithm Ed25519 instead of RSA. There is also ECDSA which has had a comparatively slow uptake, for a number of reasons that is widely available and is a reasonable choice when Ed25519 is not available. There are also post-quantum algorithms, but they are newer and adopting them today requires a careful cost-benefit analysis. First some background. RSA is an asymmetric public-key scheme, and relies on generating private keys which are the product of distinct prime numbers (typically two). The size of the resulting product, called the modulus n, is usually expressed in bit length and forms the key size. Historically RSA key sizes used to be a couple of hundred bits, then 512 bits settled as a commonly used size. With better understanding of RSA security levels, the common key size evolved into 768, 1024, and later 2048. Today s recommendations (see keylength.com) suggest that 2048 is on the weak side for long-term keys (5+ years), so there has been a trend to jump to 4096. The performance of RSA private-key operations starts to suffer at 4096, and the bandwidth requirements is causing issues in some protocols. Today 2048 and 4096 are the most common choices. My preference for non-2048/4096 RSA key sizes is based on the simple and na ve observation that if I would build a RSA key cracker, there is some likelihood that I would need to optimize the implementation for a particular key size in order to get good performance. Since 2048 and 4096 are dominant today, and 1024 were dominent some years ago, it may be feasible to build optimized versions for these three key sizes. My observation is a conservative decision based on speculation, and speculation on several levels. First I assume that there is an attack on RSA that we don t know about. Then I assume that this attack is not as efficient for some key sizes than others, either on a theoretical level, at implementation level (optimized libraries for certain characteristics), or at an economic/human level (decision to focus on common key sizes). Then I assume that by avoiding the efficient key sizes I can increase the difficulty to a sufficient level. Before analyzing whether those assumptions even remotely may make sense, it is useful to understand what is lost by selecting uncommon key sizes. This is to understand the cost of the trade-off. A significant burden would be if implementations didn t allow selecting unusual key sizes. In my experience, enough common applications support uncommon key sizes, for example GnuPG, OpenSSL, OpenSSH, FireFox, and Chrome. Some applications limit the permitted choices; this appears to be rare, but I have encountered it once. Some environments also restrict permitted choices, for example I have experienced that LetsEncrypt has introduced a requirement for RSA key sizes to be a multiples of 8. I noticed this since I chose a RSA key size of 3925 for my blog and received a certificate from LetsEncrypt in December 2015 however during renewal in 2016 it lead to an error message about the RSA key size. Some commercial CAs that I have used before restrict the RSA key size to one of 1024, 2048 or 4096 only. Some smart-cards also restrict the key sizes, sadly the YubiKey has this limitation. So it is not always possible, but possible often enough for me to be worthwhile. Another cost is that RSA signature operations are slowed down. This is because the exponentiation function is faster than multiplication, and if the bit pattern of the RSA key is a 1 followed by several 0 s, it is quicker to compute. I have not done benchmarks, but I have not experienced that this is a practical problem for me. I don t notice RSA operations in the flurry of all of other operations (network, IO) that is usually involved in my daily life. Deploying this on a large scale may have effects, of course, so benchmarks would be interesting. Back to the speculation that leads me to this choice. The first assumption is that there is an attack on RSA that we don t know about. In my mind, until there are proofs that the currently known attacks (GNFS-based attacks) are the best that can be found, or at least some heuristic argument that we can t do better than the current attacks, the probability for an unknown RSA attack is therefor, as strange as it may sound, 100%. The second assumption is that the unknown attack(s) are not as efficient for some key sizes than others. That statement can also be expressed like this: the cost to mount the attack is higher for some key sizes compared to others. At the implementation level, it seems reasonable to assume that implementing a RSA cracker for arbitrary key sizes could be more difficult and costlier than focusing on particular key sizes. Focusing on some key sizes allows optimization and less complex code. At the mathematical level, the assumption that the attack would be costlier for certain types of RSA key sizes appears dubious. It depends on the kind of algorithm the unknown attack is. For something similar to GNFS attacks, I believe the same algorithm applies equally for a RSA key size of 2048, 2730 and 4096 and that the running time depends mostly on the key size. Other algorithms that could crack RSA, such as some approximation algorithms, does not seem likely to be thwarted by using non-standard RSA key sizes either. I am not a mathematician though. At the economical or human level, it seems reasonable to say that if you can crack 95% of all keys out there (sizes 1024, 2048, 4096) then that is good enough and cracking the last 5% is just diminishing returns of the investment. Here I am making up the 95% number. Currently, I would guess that more than 95% of all RSA key sizes on the Internet are 1024, 2048 or 4096 though. So this aspect holds as long as people behave as they have done. The final assumption is that by using non-standard key sizes I raise the bar sufficiently high to make an attack impossible. To be honest, this scenario appears unlikely. However it might increase the cost somewhat, by a factor or two or five. Which might make someone target a lower hanging fruit instead. Putting my argument together, I have 1) identified some downsides of using non-standard RSA Key sizes and discussed their costs and implications, and 2) mentioned some speculative upsides of using non-standard key sizes. I am not aware of any argument that the odds of my speculation is 0% likely to be true. It appears there is some remote chance, higher than 0%, that my speculation is true. Therefor, my personal conservative approach is to hedge against this unlikely, but still possible, attack scenario by paying the moderate cost to use non-standard RSA key sizes. Of course, the QA engineer in me also likes to break things by not doing what everyone else does, so I end this with an ObXKCD.

12 September 2016

Steve Kemp: If your code accepts URIs as input..

There are many online sites that accept reading input from remote locations. For example a site might try to extract all the text from a webpage, or show you the HTTP-headers a given server sends back in response to a request. If you run such a site you must make sure you validate the schema you're given - also remembering to do that if you're sent any HTTP-redirects.
Really the issue here is a confusion between URL & URI.
The only time I ever communicated with Aaron Swartz was unfortunately after his death, because I didn't make the connection. I randomly stumbled upon the html2text software he put together, which had an online demo containing a form for entering a location. I tried the obvious input:
file:///etc/passwd
The software was vulnerable, read the file, and showed it to me. The site gives errors on all inputs now, so it cannot be used to demonstrate the problem, but on Friday I saw another site on Hacker News with the very same input-issue, and it reminded me that there's a very real class of security problems here. The site in question was http://fuckyeahmarkdown.com/ and allows you to enter a URL to convert to markdown - I found this via the hacker news submission. The following link shows the contents of /etc/hosts, and demonstrates the problem: http://fuckyeahmarkdown.example.com/go/?u=file:///etc/hosts&read=1&preview=1&showframe=0&submit=go The output looked like this:
..
127.0.0.1 localhost
255.255.255.255 broadcasthost
::1 localhost
fe80::1%lo0 localhost
127.0.0.1 stage
127.0.0.1 files
127.0.0.1 brettt..
..
In the actual output of '/etc/passwd' all newlines had been stripped. (Which I now recognize as being an artifact of the markdown processing.) UPDATE: The problem is fixed now.

30 May 2016

Daniel Stender: My work for Debian in May

No double posting this time ;-) I've got not so much spare time this month to spend on Debian, but I could work on the following packages: This series of blog postings also includes little introductions of and into new packages in the archive. This month there is: Pyinfra Pyinfra is a new project which is currently still in development state. It has been already pointed out in an interesting German article1, and is now available as package maintained within the Python Applications Team. It's currently a one man production by Nick Barrett, and eagerly developed in the past weeks (we're currently at 0.1~dev24). Pyinfra is a remote server configuration/provisioning/service deployment tool which belongs in the same software category like Puppet or Ansible2. It's for provisioning one or an array of remote servers with software packages and to configure them. Pyinfra runs agentless like Ansible, that means for using it nothing special (like a daemon) has to run on targeted servers. It's written to be used for provisioning POSIX compatible Linux systems and has alternatives when it comes to special features like package managers (e.g. supports apt as well as yum). The documentation could be found in usr/share/doc/pyinfra/html/. Here's a little crash course on how to use Pyinfra: The pyinfra CLI tool is used on the command line like this, deploy scripts, single operations or facts (see below) could be used on a single server or a multitude of remote servers:
$ pyinfra -i <inventory script/single host> <deploy script>
$ pyinfra -i <inventory script/single host> --run <operation>
$ pyinfra -i <inventory script/single host> --facts <fact>
Remote servers which are operated on must provide a working shell and they must be reachable by SSH. For connecting, --port, --user, --password, --key/--key-password and --sudo flags are available, --sudo to gain superuser rights. Root access or sudo rights of course have to be already set up. By the way, localhost could be operated on the same way. Single operations are organized in modules like "apt", "files", "init", "server" etc. With the --run option they could be used individually on servers like follows, e.g. server.user adds a new user on a single targeted system (-v adds verbosity to the pyinfra run):
$ pyinfra -i 192.0.2.10 --run server.user sam --user root --key ~/.ssh/sshkey --key-password 123456 -v
Multiple servers can be grouped in inventories, which hold the targeted hosts and data associated with them, like e.g. an inventory file farm1.py would contain lists like this:
COMPUTE_SERVERS = ['192.0.2.10', '192.0.2.11']
DATABASE_SERVERS = ['192.0.2.20', '192.0.2.21']
Group designators must be all caps. A higher level of grouping are the file names of inventory scripts, thus COMPUTE_SERVERS and DATABASE_SERVERS can be referenced to at the same time by the group designator farm1. Plus, all servers are automatically added to the group all. And, inventory scripts should be stored in the subfolder inventory/ in the project directory. Inventory files then could be used instead of specific IP addresses like this, the single operation then gets performed on all given machines in farm1.py:
$ pyinfra -i inventory/farm1.py  --run server.user sam --user root --key ~/.ssh/sshkey --key-password=123456 -v
Deployment scripts could be used together with group data files in the subfolder group_data/ in the project directory. For example, a group_data/farm1.py designates all servers given in inventory/farm1.py (by the way, all.py designates all servers), and contains the random attribute user_name (attributes must be lowercase), next to authentication data for the whole inventory group:
user_name = 'sam'
ssh_user = 'root'
ssh_key = '~/.ssh/sshkey'
ssh_key_password = '123456'
The random attribute can be picked up by a deployment script using host.data() like follows, user_name could be used again for e.g. server.user(), like this:
from pyinfra import host
from pyinfra.modules import server
server.user(host.data.user_name)
This deploy, the ensemble of inventory file, group data file and deployment script (usually placed top level in the project folder) then could be run that way:
$ pyinfra -i inventory/farm1.py deploy.py
You have guessed it, since deployment scripts are Python scripts they are fully programmable (please regard that Pyinfra is build & runs on Python 3 on Debian), and that's the main advantage point with this piece of software. Quite handy for that come Pyinfra facts, functions which check different things on remote systems and return information as Python data. Like e.g. deb_packages returns a dictionary of installed packages from a remote apt based server:
$ pyinfra -i 192.0.2.10 --fact deb_packages --user root --key ~/.ssh/sshkey --key-password=123456
 
    "192.0.2.10":  
        "libdebconfclient0": "0.192",
        "python-debian": "0.1.27",
        "libavahi-client3": "0.6.31-5",
        "dbus": "1.8.20-0+deb8u1",
        "libustr-1.0-1": "1.0.4-3+b2",
        "sed": "4.2.2-4+b1",
Using facts, Pyinfra reveals its full potential. For example, a deployment script could go like this, linux.distribution() returns a dict containing the installed distribution:
from pyinfra import host
from pyinfra.modules import apt
if host.fact.linux_distribution['name'] == 'Debian':
   apt.packages(packages='gummi', present=True, update=True)
elif host.fact.linux_distribution['name'] == 'CentOS':
   pass
I'll spare more sophisticated examples to keep this introduction simple. Beyond fancy deployment scripts, Pyinfra features an own API by which it could be programmed from the outside, and much more. But maybe that's enough to introduce Pyinfra. That are the usage basics. Pyinfra is a brand new project and it remains to be seen whether the developer can keep on further developing the tool like he does these days. For a private project it's insane to attempt to become a contender for the established "big" free configuration management tools and frameworks, but, if Puppet has become too complex in the meanwhile or not3, I really don't think that's the point here. Pyinfra follows an own approach in being programmable the way which it is. And it's definitely not harm to have it in the toolbox already, not trying to replace nothing. Brainstorm After the first package has been in experimental, the Brainstorm library from Swiss AI research institute IDSIA4 is now available as python3-brainstorm in unstable. Brainstorm is a lean, easy-to-use library for setting up deep learning networks (multiple layered artificial neural networks) for machine learning applications like for image and speech recognition or natural language processing. To set up a working training network for a classifier for handwritten digits like the MNIST dataset (a usual "hello world") just takes a couple of lines, like an example demonstrates. The package is maintained within the Debian Python Modules Team. The Debian package ships a couple of examples in /usr/share/python3-brainstorm/examples (the data/ and examples/ folders of the upstream tarball are combined here). Among them there are5: The current documentation in /usr/share/doc/python3-brainstorm/html/ isn't complete yet (several chapters are under construction), but there's a walkthrough on the CIFAR-10 example. The MNIST example has been extended by Github user pinae, and has been explained in German C't recently6. What are the perspectives for further development? Like Zhou Mo confirmed, there are a couple of deep learning frameworks around having a rather poor outlook since there have been abandoned after being completed as PhD projects. There's really no point for thriving to have them all in Debian, like the ITP of Minerva has been given up partly for this reason, there weren't any commits since 08/2015 (and because cuDNN isn't available and most likely won't). Brainstorm, 0.5 have been released 05/2015, also was a PhD project as IDSIA. It's stated on Github that the project is "under active development", but the rather sparse project page on the other side expresses the "hope the community will help us to further improve Brainstorm". This sentence much often implies that the developers are not actively working on the project. But there are recent commits and it looks that upstream is active and could be reached when there are problems, and that the project is active. So I don't think we're riding a dead horse, here. The downside for Brainstorm in Debian is, it seems that the libraries which are needed for GPU accelerated processing can't be fully provided. Pycuda is available, but scikit-cuda (an additional library which provides wrappers for CUDA features like CUBLAS, CUFFT and CUSOLVER) is not and won't be, because the CULA Dense Toolkit (scikit-cuda also contains wrappers for also that) is not available freely as source. Because of that, a dependency against pycuda, not even as Suggests (it's non-free), has been spared. Without GPU acceleration, Brainstorm computes the matrices on openBLAS using a Cython wrapper on the NumpyHandler, and the PyCudaHandler couldn't be used. openBLAS makes pretty good use of the available hardware (it distributes over all available CPU cores), but it's not yet possible to run Brainstorm full throttle using available floating point devices to reduce training times, which becomes crucial when the projects are getting bigger. Brainstorm belongs to the number of deep learning frameworks already being or becoming available in Debian. Currently there is: I've checked over Microsoft's CNTK, but although it's also set free recently I have my doubts if that could be included. Apparently there are dependencies against non-free software and most likely other issues. So much for a little update on the state of deep learning in Debian, please excuse if my radar misses something.

  1. Tim Sch rmann: "Schlangen l: Automatisiertes Service-Deployment mit Pyinfra". In: IT-Administrator 05/2016, pp. 90-95.
  2. For a comparison of configuration management software like this, see B wetter/Johannsen/Steig: "Baukastensysteme: Konfigurationsmanagement mit Open-Source-Software". In: iX 04/2016, pp. 94-99 (please excuse the prevalence of German articles in the pointers, I've just have them at hand).
  3. On the points of critique on Puppet, see Martin Loschwitz: "David gegen Goliath Zwei Welten treffen aufeinander: Puppet und Ansible". In Linux-Magazin 01/2016, 50-54.
  4. See the interview with IDSIA's deep learning guru J rgen Schmidhuber in German C't 2014/09, p. 148
  5. The examples scripts need some more finetuning. To run the data creation scripts in place the environment variable BRAINSTORM_DATA_DIR could be set, but the trained networks are currently tried to write in place. So please copy the scripts into some workspace if you want to try them out. I'll patch the example scripts to run out-of-the-box, soon.
  6. Johannes Merkert: "Ziffernlerner. Ein k nstliches neuronales Netz selber gebaut". In: C't 2016/06, p. 142-147. Web: http://www.heise.de/ct/ausgabe/2016-6-Ein-kuenstliches-neuronales-Netz-selbst-gebaut-3118857.html.
  7. See Ramon Wartala: "Tiefensch rfe: Deep learning mit NVIDIAs Jetson-TX1-Board und dem Caffe-Framework". In: iX 06/2016, pp. 100-103
  8. https://lists.debian.org/debian-science/2016/03/msg00016.html

10 May 2016

Lars Wirzenius: Qvarn Platform announcement

In March we started a new company, to develop and support the software whose development I led at my previous job. The software is Qvarn, and it's fully free software, licensed under AGPL3+. The company is QvarnLabs (no website yet). Our plan is to earn a living from this, and our hope is to provide software that is actually useful for helping various organisations handle data securely. The first press release about Qvarn was sent out today. We're still setting up the company and getting operational, but a little publicity never hurts. (Even if it is more marketing-speak and self-promotion than I would normally put on my blog.) So this is what I do for a living now.

The development of the open source Qvarn Platform was led by QvarnLabs CEO Kaius H ggblom (left) and CTO Lars Wirzenius. Helsinki, Finland 10.05.2016 With Privacy by Design, integrated Gluu access management and comprehensive support for regulatory data compliance, Qvarn is set to become the Europe-wide platform of choice for managing workforce identities and providing associated value-added services. Construction industry federations in Sweden, Finland and the Baltic States have been using the Qvarn Platform (http://www.qvarn.org) since October 2015 to securely manage the professional digital identities of close to one million construction workers. Developed on behalf of these same federations, Qvarn is now free and open source software; making it a compelling solution for any organization that needs to manage a secure register of workers data. "There is something universal and fundamental at the core of the Qvarn platform. And that s trust," said Qvarn evangelist Kaius H ggblom. "We decided to make it free, open source and include Gluu access management because we wanted all those using Qvarn or contributing to its continued development to have the freedom to work with the platform in whatever way is best for them." Qvarn has been designed to meet the requirements of the European Union s new General Data Protection Regulation (GDPR), enabling organizations that use the platform to ensure their compliance with the new law. Qvarn has also incorporated the principles of Privacy by Design to minimize the disclosure of non-essential personal information and to give people more control over their data. "Today, Qvarn is used by the construction industry as a way to manage the data of employees, many of whom frequently move across borders. In this way the platform helps to combat the grey economy in the building sector, thereby improving quality and safety, while simultaneously protecting the professional identity data of almost a million individuals," said H ggblom. "Qvarn is so flexible and secure that we envision it becoming the preferred platform for the provision of any value-added services with an identity management component, eventually even supporting monetary transactions." Qvarn is a cloud based solution supported to run on both Amazon Web Services (AWS) and OpenStack. In partnership with Gluu, the platform delivers an out-of-the-box solution that uses open and standard protocols to provide powerful yet flexible identity and access management, including mechanisms for appropriate authentication and authorization. "Qvarn's identity management and governance capabilities perfectly compliment the Gluu Server's access management features," said Founder and CEO of Gluu, Michael Schwartz. "Free open source software (FOSS) is essential to the future of identity and access management. And the FOSS development methodology provides the transparency that is needed to foster the strong sense of community upon which a vibrant ecosystem thrives." Qvarn s development team continues to be led by recognized open source developer and platform architect Lars Wirzenius. He has been developing free and open source software for 30 years and is a renowned expert in the Linux environment, with a particular focus on the Debian distribution. Lars works at all levels of software development from writing code to designing system architecture. About the Qvarn Platform: The Qvarn Platform is free and open source software for managing workforce identities. Qvarn is integrated with the Gluu Server s access management features out of the box, using open and standard protocols to provide the platform with a single common digital identity and mechanisms for appropriate authentication and authorization. A cloud based solution, Qvarn is supported to run on both Amazon Web Services (AWS) and OpenStack. Privacy by Design is central to the architecture of Qvarn and the platform has been third party audited to a security level of HIGH. http://www.qvarn.org For more information, please contact:
Andrew Flowers
andrew.flowers@ellisnichol.com
+358 40 161 5668

17 April 2016

Andreas Metzler: balance sheet snowboarding season 2015/16

A very weak season, mainly due to two reasons: Here is the balance sheet:
2005/06 2006/07 2007/08 2008/09 2009/10 2010/11 2011/12 2012/13 2013/14 2014/15 2015/2016
number of (partial) days2517293730302523302417
Dam ls101051016231042994
Diedamskopf1542423134141911312
Warth/Schr cken03041310021
total meters of altitude12463474096219936226774202089203918228588203562274706224909138037
highscore10247m8321m12108m11272m11888m10976m13076m13885m12848m1327811015
# of runs309189503551462449516468597530354

10 April 2016

Russ Allbery: Largish haul

Let's see if I can scrounge through all of my now-organized directories of ebooks and figure out what I haven't recorded here yet. At least the paper books make that relatively easy, since I don't shelve them until I post them. (Yeah, yeah, I should actually make a database.) Hugh Aldersey-Williams Periodic Tales (nonfiction)
Sandra Ulbrich Almazan SF Women A-Z (nonfiction)
Radley Balko Rise of the Warrior Cop (nonfiction)
Peter V. Brett The Warded Man (sff)
Lois McMaster Bujold Gentleman Jole and the Red Queen (sff)
Fred Clark The Anti-Christ Handbook Vol. 2 (nonfiction)
Dave Duncan West of January (sff)
Karl Fogel Producing Open Source Software (nonfiction)
Philip Gourevitch We Wish to Inform You That Tomorrow We Will Be Killed With Our Families (nonfiction)
Andrew Groen Empires of EVE (nonfiction)
John Harris @ Play (nonfiction)
David Hellman & Tevis Thompson Second Quest (graphic novel)
M.C.A. Hogarth Earthrise (sff)
S.L. Huang An Examination of Collegial Dynamics... (sff)
S.L. Huang & Kurt Hunt Up and Coming (sff anthology)
Kameron Hurley Infidel (sff)
Kevin Jackson-Mead & J. Robinson Wheeler IF Theory Reader (nonfiction)
Rosemary Kirstein The Lost Steersman (sff)
Rosemary Kirstein The Language of Power (sff)
Merritt Kopas Videogames for Humans (nonfiction)
Alisa Krasnostein & Alexandra Pierce (ed.) Letters to Tiptree (nonfiction)
Mathew Kumar Exp. Negatives (nonfiction)
Ken Liu The Grace of Kings (sff)
Susan MacGregor The Tattooed Witch (sff)
Helen Marshall Gifts for the One Who Comes After (sff collection)
Jack McDevitt Coming Home (sff)
Seanan McGuire A Red-Rose Chain (sff)
Seanan McGuire Velveteen vs. The Multiverse (sff)
Seanan McGuire The Winter Long (sff)
Marc Miller Agent of the Imperium (sff)
Randal Munroe Thing Explainer (graphic nonfiction)
Marguerite Reed Archangel (sff)
J.K. Rowling Harry Potter: The Complete Collection (sff)
K.J. Russell Tides of Possibility (sff anthology)
Robert J. Sawyer Starplex (sff)
Bruce Schneier Secrets & Lies (nonfiction)
Mike Selinker (ed.) The Kobold Game to Board Game Design (nonfiction)
Douglas Smith Chimerascope (sff collection)
Jonathan Strahan Fearsome Journeys (sff anthology)
Nick Suttner Shadow of the Colossus (nonfiction)
Aaron Swartz The Boy Who Could Change the World (essays)
Caitlin Sweet The Pattern Scars (sff)
John Szczepaniak The Untold History of Japanese Game Developers I (nonfiction)
John Szczepaniak The Untold History of Japanese Game Developers II (nonfiction)
Jeffrey Toobin The Run of His Life (nonfiction)
Hayden Trenholm Blood and Water (sff anthology)
Coen Teulings & Richard Baldwin (ed.) Secular Stagnation (nonfiction)
Ursula Vernon Book of the Wombat 2015 (graphic nonfiction)
Ursula Vernon Digger (graphic novel) Phew, that was a ton of stuff. A bunch of these were from two large StoryBundle bundles, which is a great source of cheap DRM-free ebooks, although still rather hit and miss. There's a lot of just fairly random stuff that's been accumulating for a while, even though I've not had a chance to read very much. Vacation upcoming, which will be a nice time to catch up on reading.

28 March 2016

Joey Hess: type safe multi-OS Propellor

Propellor was recently ported to FreeBSD, by Evan Cofsky. This new feature led me down a two week long rabbit hole to make it type safe. In particular, Propellor needed to be taught that some properties work on Debian, others on FreeBSD, and others on both. The user shouldn't need to worry about making a mistake like this; the type checker should tell them they're asking for something that can't fly.
-- Is this a Debian or a FreeBSD host? I can't remember, let's use both package managers!
host "example.com" $ props
    & aptUpgraded
    & pkgUpgraded
As of propellor 3.0.0 (in git now; to be released soon), the type checker will catch such mistakes. Also, it's really easy to combine two OS-specific properties into a property that supports both OS's:
upgraded = aptUpgraded  pickOS  pkgUpgraded
type level lists and functions The magick making this work is type-level lists. A property has a metatypes list as part of its type. (So called because it's additional types describing the type, and I couldn't find a better name.) This list can contain one or more OS's targeted by the property:
aptUpgraded :: Property (MetaTypes '[ 'Targeting 'OSDebian, 'Targeting 'OSBuntish ])
pkgUpgraded :: Property (MetaTypes '[ 'Targeting 'OSFreeBSD ])
In Haskell type-level lists and other DataKinds are indicated by the ' if you have not seen that before. There are some convenience aliases and type operators, which let the same types be expressed more cleanly:
aptUpgraded :: Property (Debian + Buntish)
pkgUpgraded :: Property FreeBSD
Whenever two properties are combined, their metatypes are combined using a type-level function. Combining aptUpgraded and pkgUpgraded will yield a metatypes that targets no OS's, since they have none in common. So will fail to type check. My implementation of the metatypes lists is hundreds of lines of code, consisting entirely of types and type families. It includes a basic implementation of singletons, and is portable back to ghc 7.6 to support Debian stable. While it takes some contortions to support such an old version of ghc, it's pretty awesome that the ghc in Debian stable supports this stuff. extending beyond targeted OS's Before this change, Propellor's Property type had already been slightly refined, tagging them with HasInfo or NoInfo, as described in making propellor safer with GADTs and type families. I needed to keep that HasInfo in the type of properties. But, it seemed unnecessary verbose to have types like Property NoInfo Debian. Especially if I want to add even more information to Property types later. Property NoInfo Debian NoPortsOpen would be a real mouthful to need to write for every property. Luckily I now have this handy type-level list. So, I can shove more types into it, so Property (HasInfo + Debian) is used where necessary, and Property Debian can be used everywhere else. Since I can add more types to the type-level list, without affecting other properties, I expect to be able to implement type-level port conflict detection next. Should be fairly easy to do without changing the API except for properties that use ports. singletons As shown here, pickOS makes a property that decides which of two properties to use based on the host's OS.
aptUpgraded :: Property DebianLike
aptUpgraded = property "apt upgraded" (apt "upgrade"  requires  apt "update")
pkgUpgraded :: Property FreeBSD
pkgUpgraded = property "pkg upgraded" (pkg "upgrade")
    
upgraded :: Property UnixLike
upgraded = (aptUpgraded  pickOS  pkgUpgraded)
     describe  "OS upgraded"
Any number of OS's can be chained this way, to build a property that is super-portable out of simple little non-portable properties. This is a sweet combinator! Singletons are types that are inhabited by a single value. This lets the value be inferred from the type, which came in handy in building the pickOS property combinator. Its implementation needs to be able to look at each of the properties at runtime, to compare the OS's they target with the actial OS of the host. That's done by stashing a target list value inside a property. The target list value is inferred from the type of the property, thanks to singletons, and so does not need to be passed in to property. That saves keyboard time and avoids mistakes. is it worth it? It's important to consider whether more complicated types are a net benefit. Of course, opinions vary widely on that question in general! But let's consider it in light of my main goals for Propellor:
  1. Help save the user from pushing a broken configuration to their machines at a time when they're down in the trenches dealing with some urgent problem at 3 am.
  2. Advance the state of the art in configuration management by taking advantage of the state of the art in strongly typed haskell.
This change definitely meets both criteria. But there is a tradeoff; it got a little bit harder to write new propellor properties. Not only do new properties need to have their type set to target appropriate systems, but the more polymorphic code is, the more likely the type checker can't figure out all the types without some help. A simple example of this problem is as follows.
foo :: Property UnixLike
foo = p  requires  bar
  where
    p = property "foo" $ do
        ...
The type checker will complain that "The type variable metatypes1 is ambiguous". Problem is that it can't infer the type of p because many different types could be combined with the bar property and all would yield a Property UnixLike. The solution is simply to add a type signature like p :: Property UnixLike Since this only affects creating new properties, and not combining existing properties (which have known types), it seems like a reasonable tradeoff. things to improve later There are a few warts that I'm willing to live with for now... Currently, Property (HasInfo + Debian) is different than Property (Debian + HasInfo), but they should really be considered to be the same type. That is, I need type-level sets, not lists. While there's a type level sets library for hackage, it still seems to require a specific order of the set items when writing down a type signature. Also, using ensureProperty, which runs one property inside the action of another property, got complicated by the need to pass it a type witness.
foo = Property Debian
foo = property' $ \witness -> do
    ensureProperty witness (aptInstall "foo")
That witness is used to type check that the inner property targets every OS that the outer property targets. I think it might be possible to store the witness in the monad, and have ensureProperty read it, but it might complicate the type of the monad too much, since it would have to be parameterized on the type of the witness. Oh no, I mentioned monads. While type level lists and type functions and generally bending the type checker to my will is all well and good, I know most readers stop reading at "monad". So, I'll stop writing. ;) thanks Thanks to David Miani who answered my first tentative question with a big hunk of example code that got me on the right track. Also to many other people who answered increasingly esoteric Haskell type system questions. Also thanks to the Shuttleworth foundation, which funded this work by way of a Flash Grant.

4 February 2016

Daniel Pocock: Australians stuck abroad and alleged sex crimes

Two Australians have achieved prominence (or notoriety, depending on your perspective) for the difficulty in questioning them about their knowledge of alleged sex crimes. One is Julian Assange, holed up in the embassy of Ecuador in London. He is back in the news again today thanks to a UN panel finding that the UK is effectively detaining him, unlawfully, in the Ecuadorian embassy. The effort made to discredit and pursue Assange and other disruptive technologists, such as Aaron Swartz, has an eerie resemblance to the way the Inquisition hunted witches in the middle ages and beyond. The other Australian stuck abroad is Cardinal George Pell, the most senior figure in the Catholic Church in Australia. The Royal Commission into child sex abuse by priests has heard serious allegations claiming the Cardinal knew about and covered up abuse. This would appear far more sinister than anything Mr Assange is accused of. Like Mr Assange, the Cardinal has been unable to travel to attend questioning in person. News reports suggest he is ill and can't leave Rome, although he is being accommodated in significantly more comfort than Mr Assange. If you had to choose, which would you prefer to leave your child alone with?

14 January 2016

Vincent Sanders: Ampere was the Newton of Electricity.

I think Maxwell was probably right, certainly the unit of current Ampere gives his name to has been a concern of mine recently.

Regular readers may have possibly noticed my unhealthy obsession with single board computers. I have recently rehomed all the systems into my rack which threw up a small issue of powering them all. I had been using an ad-hoc selection of USB wall warts and adapters but this ended up needing nine mains sockets and short of purchasing a very expensive PDU for the rack would have needed a lot of space.

Additionally having nine separate convertors from mains AC to low voltage DC was consuming over 60Watts for 20W of load! The majority of these supplies were simply delivering 5V either via micro USB or DC barrel jack.

Initially I considered using a ten port powered USB hub but this seemed expensive as I was not going to use the data connections, it also had a limit of 5W per port and some of my systems could potentially use more power than that so I decided to build my own supply.

PSU module from ebay
A quick look on ebay revealed that a 150W (30A at 5V) switching supply could be had from a UK vendor for 9.99 which seemed about right. An enclosure, fused and switched IEC inlet, ammeter/voltmeter with shunt and suitable cables were acquired for another 15

Top view of the supply all wired up
A little careful drilling and cutting of the enclosure made openings for the inlets, cables and display. These were then wired together with crimped and insulated spade and ring connectors. I wanted this build to be safe and reliable so care was taken to get the neatest layout I could manage with good separation between the low and high voltage cabling.

Completed supply with all twelve outputs wired up
The result is a neat supply with twelve outputs which i can easily extend to eighteen if needed. I was pleasantly surprised to discover that even with twelve SBC connected generating 20W load the power drawn by the supply was 25W or about 80% efficiency instead of the 33% previously achieved.

The inbuilt meter allows me to easily see the load on the supply which so far has not risen above 5A even at peak draw, despite the cubitruck and BananaPi having spinning rust hard drives attached, so there is plenty of room for my SBC addiction to grow (I already pledged for a Pine64).

Supply installed in the rack with some of the SBC connected
Overall I am pleased with how this turned out and while there are no detailed design files for this project it should be easy to follow if you want to repeat it. One note of caution though, this project has mains wiring and while I am confident in my own capabilities dealing with potentially lethal voltages I cannot be responsible for anyone else so caveat emptor!

5 January 2016

Benjamin Mako Hill: Celebrate Aaron Swartz in Seattle (or Atlanta, Chicago, Dallas, NYC, SF)

I m organizing an event at the University of Washington in Seattle that involves a reading, the screening of a documentary film, and a Q&A about Aaron Swartz. The event coincides with the third anniversary of Aaron s death and the release of a new book of Swartz s writing that I contributed to. aaronsw-tiob_bwcstw The event is free and open the public and details are below:

WHEN: Wednesday, January 13 at 6:30-9:30 p.m.

WHERE: Communications Building (CMU) 120, University of Washington

We invite you to celebrate the life and activism efforts of Aaron Swartz, hosted by UW Communication professor Benjamin Mako Hill. The event is next week and will consist of a short book reading, a screening of a documentary about Aaron s life, and a Q&A with Mako who knew Aaron well details are below. No RSVP required; we hope you can join us.

Aaron Swartz was a programming prodigy, entrepreneur, and information activist who contributed to the core Internet protocol RSS and co-founded Reddit, among other groundbreaking work. However, it was his efforts in social justice and political organizing combined with his aggressive approach to promoting increased access to information that entangled him in a two-year legal nightmare that ended with the taking of his own life at the age of 26.

January 11, 2016 marks the third anniversary of his death. Join us two days later for a reading from a new posthumous collection of Swartz s writing published by New Press, a showing of The Internet s Own Boy (a documentary about his life), and a Q&A with UW Communication professor Benjamin Mako Hill a former roommate and friend of Swartz and a contributor to and co-editor of the first section of the new book. If you re not in Seattle, there are events with similar programs being organized in Atlanta, Chicago, Dallas, New York, and San Francisco. All of these other events will be on Monday January 11 and registration is required for all of them. I will be speaking at the event in San Francisco.

4 January 2016

Benjamin Mako Hill: The Boy Who Could Change the World: The Writings of Aaron Swartz

The New Press has published a new collection of Aaron Swartz s writing called The Boy Who Could Change the World: The Writings of Aaron Swartz. I worked with Seth Schoen to introduce and help edit the opening section of book that includes Aaron s writings on free culture, access to information and knowledge, and copyright. Seth and I have put our introduction online under an appropriately free license (CC BY-SA). aaronsw_book_coverOver the last week, I ve read the whole book again. I think the book really is a wonderful snapshot of Aaron s thought and personality. It s got bits that make me roll my eyes, bits that make me want to shout in support, and bits that continue to challenge me. It all makes me miss Aaron terribly. I strongly recommend the book. Because the publication is post-humous, it s meant that folks like me are doing media work for the book. In honor of naming the book their progressive pick of the week, Truthout has also published an interview with me about Aaron and the book. Other folks who introduced and/or edited topical sections in the book are David Auerbach (Computers), David Segal (Politics), Cory Doctorow (Media), James Grimmelmann (Books and Culture), and Astra Taylor (Unschool). The book is introduced by Larry Lessig.

2 January 2016

Daniel Pocock: The great life of Ian Murdock and police brutality in context

Tributes: (You can Follow or Tweet about this blog on Twitter) Over the last week, people have been saying a lot about the wonderful life of Ian Murdock and his contributions to Debian and the world of free software. According to one news site, a San Francisco police officer, Grace Gatpandan, has been doing the opposite, starting a PR spin operation, leaking snippets of information about what may have happened during Ian's final 24 hours. Sadly, these things are now starting to be regurgitated without proper scrutiny by the mainstream press (note the erroneous reference to SFGate with link to SFBay.ca, this is British tabloid media at its best). The report talks about somebody (no suggestion that it was even Ian) "trying to break into a residence". Let's translate that from the spin-doctor-speak back to English: it is the silly season, when many people have a couple of extra drinks and do silly things like losing their keys. "a residence", or just their own home perhaps? Maybe some AirBNB guest arriving late to the irritation of annoyed neighbours? Doesn't the choice of words make the motive sound so much more sinister? Nobody knows the full story and nobody knows if this was Ian, so snippets of information like this are inappropriate, especially when somebody is deceased. Did they really mean to leave people with the impression that one of the greatest visionaries of the Linux world was also a cat burglar? That somebody who spent his life giving selflessly and generously for the benefit of the whole world (his legacy is far greater than Steve Jobs, as Debian comes with no strings attached) spends the Christmas weekend taking things from other people's houses in the dark of the night? The report doesn't mention any evidence of a break-in or any charges for breaking-in. If having a few drinks and losing your keys in December is such a sorry state to be in, many of us could potentially be framed in the same terms at some point in our lives. That is one of the reasons I feel so compelled to write this: somebody else could be going through exactly the same experience at the moment you are reading this. Any of us could end up facing an assault as unpleasant as the tweets imply at some point in the future. At least I can console myself that as a privileged white male, the risk to myself is much lower than for those with mental illness, the homeless, transgender, Muslim or black people but as the tweets suggest, it could be any of us. The story reports that officers didn't actually come across Ian breaking in to anything, they encountered him at a nearby street corner. If he had weapons or drugs or he was known to police that would have almost certainly been emphasized. Is it right to rush in and deprive somebody of their liberties without first giving them an opportunity to identify themselves and possibly confirm if they had a reason to be there? The report goes on, "he was belligerent", "he became violent", "banging his head" all by himself. How often do you see intelligent and successful people like Ian Murdock spontaneously harming themselves in that way? Can you find anything like that in any of the 4,390 Ian Murdock videos on YouTube? How much more frequently do you see reports that somebody "banged their head", all by themselves of course, during some encounter with law enforcement? Do police never make mistakes like other human beings? If any person was genuinely trying to spontaneously inflict a head injury on himself, as the police have suggested, why wouldn't the police leave them in the hospital or other suitable care? Do they really think that when people are displaying signs of self-harm, rounding them up and taking them to jail will be in their best interests? Now, I'm not suggesting this started out with some sort of conspiracy. Police may have been at the end of a long shift (and it is a disgrace that many US police are not paid for their overtime) or just had a rough experience with somebody far more sinister. On the other hand, there may have been a mistake, gaps in police training or an inappropriate use of a procedure that is not always justified, like a strip search, that causes profound suffering for many victims. A select number of US police forces have been shamed around the world for a series of incidents of extreme violence in recent times, including the death of Michael Brown in Ferguson, shooting Walter Scott in the back, death of Freddie Gray in Baltimore and the attempts of Chicago's police to run an on-shore version of Guantanamo Bay. Beyond those highly violent incidents, the world has also seen the abuse of Ahmed Mohamed, the Muslim schoolboy arrested for his interest in electronics and in 2013, the suicide of Aaron Swartz which appears to be a direct consequence of the "Justice" department's obsession with him. What have the police learned from all this bad publicity? Are they changing their methods, or just hiring more spin doctors? If that is their response, then doesn't it leave them with a cruel advantage over those people who were deceased? Isn't it standard practice for some police to simply round up anybody who is a bit lost and write up a charge sheet for resisting arrest or assaulting an officer as insurance against questions about their own excessive use of force? When British police executed Jean Charles de Menezes on a crowded tube train and realized they had just done something incredibly outrageous, their PR office went to great lengths to try and protect their image, even photoshopping images of Menezes to make him look more like some other suspect in a wanted poster. To this day, they continue to refer to Menezes as a victim of the terrorists, could they be any more arrogant? While nobody believes the police woke up that morning thinking "let's kill some random guy on the tube", it is clear they made a mistake and like many people (not just police), they immediately prioritized protecting their reputation over protecting the truth. Nobody else knows exactly what Ian was doing and exactly what the police did to him. We may never know. However, any disparaging or irrelevant comments from the police should be viewed with some caution. The horrors of incarceration It would be hard for any of us to understand everything that an innocent person goes through when detained by the police. The recently released movie about The Stanford Prison Experiment may be an interesting place to start, a German version produced in 2001, Das Experiment, is also very highly respected. The United States has the largest prison population in the world and the second-highest per-capita incarceration rate. Many, including some on death row, are actually innocent, in the wrong place at the wrong time, without the funds to hire an attorney. The system, and the police and prison officers who operate it, treat these people as packages on a conveyor belt, without even the most basic human dignity. Whether their encounter lasts for just a few hours or decades, is it any surprise that something dies inside them when they discover this cruel side of American society? Worldwide, there is an increasing trend to make incarceration as degrading as possible. People may be innocent until proven guilty, but this hasn't stopped police in the UK from locking up and strip-searching over 4,500 children in a five year period, would these children go away feeling any different than if they had an encounter with Jimmy Saville or Rolf Harris? One can only wonder what they do to adults. What all this boils down to is that people shouldn't really be incarcerated unless it is clear the danger they pose to society is greater than the danger they may face in a prison. What can people do for Ian and for justice? Now that these unfortunate smears have appeared, it would be great to try and fill the Internet with stories of the great things Ian has done for the world. Write whatever you feel about Ian's work and your own experience of Debian. While the circumstances of the final tweets from his Twitter account are confusing, the tweets appear to be consistent with many other complaints about US law enforcement. Are there positive things that people can do in their community to help reduce the harm? Sending books to prisoners (the UK tried to ban this) can make a difference. Treat them like humans, even if the system doesn't. Recording incidents of police activities can also make a huge difference, such as the video of the shooting of Walter Scott or the UK police making a brutal unprovoked attack on a newspaper vendor. Don't just walk past a situation and assume everything is under control. People making recordings may find themselves in danger, it is recommended to use software that automatically duplicates each recording, preferably to the cloud, so that if the police ask you to delete such evidence, you can let them watch you delete it and still have a copy. Can anybody think of awards that Ian Murdock should be nominated for, either in free software, computing or engineering in general? Some, like the prestigious Queen Elizabeth Prize for Engineering can't be awarded posthumously but others may be within reach. Come and share your ideas on the debian-project mailing list, there are already some here. Best of all, Ian didn't just build software, he built an organization, Debian. Debian's principles have helped to unite many people from otherwise different backgrounds and carry on those principles even when Ian is no longer among us. Find out more, install it on your computer or even look for ways to participate in the project.

30 December 2015

Bits from Debian: Debian mourns the passing of Ian Murdock

Ian Murdock With a heavy heart Debian mourns the passing of Ian Murdock, stalwart proponent of Free Open Source Software, Father, Son, and the 'ian' in Debian. Ian started the Debian project in August of 1993, releasing the first versions of Debian later that same year. Debian would go on to become the world's Universal Operating System, running on everything from embedded devices to the space station. Ian's sharp focus was on creating a Distribution and community culture that did the right thing, be it ethically, or technically. Releases went out when they were ready, and the project's staunch stance on Software Freedom are the gold standards in the Free and Open Source world. Ian's devotion to the right thing guided his work, both in Debian and in the subsequent years, always working towards the best possible future. Ian's dream has lived on, the Debian community remains incredibly active, with thousands of developers working untold hours to bring the world a reliable and secure operating system. The thoughts of the Debian Community are with Ian's family in this hard time. His family has asked for privacy during this difficult time and we very much wish to respect that. Within our Debian and the larger Linux community condolences may be sent to in-memoriam-ian@debian.org where they will be kept and archived.

15 November 2015

Manuel A. Fernandez Montecelo: Work on aptitude

Midsummer for me is also known as Noite do Lume Novo (literally New Fire Night ), one of the big calendar events of the year, marking the end of the school year and the beginning of summer. On this day, there are celebrations not very unlike the bonfires in the Guy Fawkes Night in England or Britain [1]. It is a bit different in that it is not a single event for the masses, more of a friends and neighbours thing, and that it lasts for a big chunk of the night (sometimes until morning). Perhaps for some people, or outside bigger towns or cities, Guy Fawkes Night is also celebrated in that way and that's why during the first days of November there are fireworks rocketing and cracking in the neighbourhoods all around. Like many other celebrations around the world involving bonfires, many of them also happening around the summer solstice, it is supposed to be a time of renewal of cycles, purification and keeping the evil spirits away; with rituals to that effect like jumping over the fire when the flames are not high and it is safe enough. So it was fitting that, in the middle of June (almost Midsummer in the northern hemisphere), I learnt that I was about to leave my now-previous job, which is a pretty big signal and precursor for renewal (and it might have something to do with purifying and keeping the evil away as well ;-) ). Whatever... But what does all of this have to do with aptitude or Debian, anyway? For one, it was a question of timing. While looking for a new job (and I am still at it), I had more spare time than usual. DebConf 15 @ Heidelberg was within sight, and for the first time circumstances allowed me to attend this event. It also coincided with the time when I re-gained access to commit to aptitude on the 19th of June. Which means Renewal. End of June was also the time of the announcement of the colossal GCC-5/C++11 ABI transition in Debian, that was scheduled to start on the 1st of August, just before the DebConf. Between 2 and 3 thousand source packages in Debian were affected by this transition, which a few months later is not yet finished (although the most important parts were completed by mid-end September). aptitude itself is written in C++, and depends on several libraries written in C++, like Boost, Xapian and SigC++. All of them had to be compiled with the new C++11 ABI of GCC-5, in unison and in a particular order, for aptitude to continue to work (and for minimal breakage). aptitude and some dependencies did not even compile straight away, so this transition meant that aptitude needed attention just to keep working. Having recently being awarded again with the Aptitude Hat, attending DebConf for the first time and sailing towards the Transition Maelstrom, it was a clear sign that Something Had to Be Done (to avoid the sideways looks and consequent shame at DebConf, if nothing else). Happily (or a bit unhappily for me, but let's pretend...), with the unexpected free time in my hands, I changed the plans that I had before re-gaining the Aptitude Hat (some of them involving Debian, but in other ways maybe I will post about that soon). In July I worked to fix the problems before the transition started, so aptitude would be (mostly) ready, or in the worst case broken only for a few days, while the chain of dependencies was rebuilt. But apart from the changes needed for the new GCC-5, it was decided at the last minute that Boost 1.55 would not be rebuilt with the new ABI, and that the only version with the new ABI would be 1.58 (which caused further breakage in aptitude, was added to experimental only a few days before, and was moved to unstable after the transition had started). Later, in the first days of the transition, aptitude was affected for a few days by breakage in the dependencies, due to not being compiled in sequence according to the transition levels (so with a mix of old and new ABI). With the critical intervention of Axel Beckert (abe / XTaran), things were not so bad as they could have been. He was busy testing and uploading in the critical days when I was enjoying a small holiday on my way to DebConf, with minimal internet access and communicating almost exclusively with him; and he promptly tended the complaints arriving in the Bug Tracking System and asked for rebuilds of the dependencies with the new ABI. He also brought the packaging up to shape, which had decayed a bit in the last few years. Gruesome Challenges But not all was solved yet, more storms were brewing and started to appear in the horizon, in the form of clouds of fire coming from nearby realms. The APT Deities, which had long ago spilled out their secret, inner challenge (just the initial paragraphs), were relentless. Moreover, they were present at Heidelberg in full force, in or close to their home grounds, and they were Marching Decidedly towards Victory: apt BTS Graph, 2015-11-15 In the talk @ DebConf This APT has Super Cow Powers (video available), by David Kalnischkies, they told us about the niceties of apt 1.1 (still in experimental but hopefully coming to unstable soon), and they boasted about getting the lead in our arms race (should I say bugs race?) by a few open bug reports. This act of provocation further escalated the tensions. The fierce competition which had been going on for some time gained new heights. So much so that APT Deities and our team had to sit together in the outdoor areas of the venue and have many a weissbier together, while discussing and fixing bugs. But beneath the calm on the surface, and while pretending to keep good diplomatic relations, I knew that Something Had to Be Done, again. So I could only do one thing jump over the bonfire and Keep the Evil away, be that Keep Evil bugs Away or Keep Evil APT Deities Away from winning the challenge, or both. After returning from DebConf I continued to dedicate time to the project, more than a full time job in some weeks, and this is what happened in the last few months, summarised in another graph, showing the evolution of the BTS for aptitude: aptitude BTS Graph, 2015-11-15 The numbers for apt right now (15th November 2015) are: The numbers for aptitude right now are: The Aftermath As we can see, for the time being I could keep the Evil at bay, both in terms of bugs themselves and re-gaining the lead in the bugs race the Evil APT Deities were thwarted again in their efforts. ... More seriously, as most of you suspected, the graph above is not the whole truth, so I don't want to boast too much. A big part of the reduction in the number of bugs is because of merging duplicates, closing obsolete bugs, applying translations coming from multiple contributors, or simple fixes like typos and useful suggestions needing minor changes. Many of remaining problems are comparatively more difficult or time consuming that the ones addressed so far (except perhaps avoiding the immediate breakage of the transition, that took weeks to solve), and there are many important problems still there, chief among those is aptitude offering very poor solutions to resolve conflicts. Still, even the simplest of the changes takes effort, and triaging hundreds of bugs is not fun at all and mostly a thankless effort althought there is the occasionally kind soul that thanks you for handling a decade-old bug. If being subjected to the rigours of the BTS and reading and solving hundreds of bug reports is not Purification, I don't know what it is. Apart from the triaging, there were 118 bugs closed (or pending) due to changes made in the upstream part or the packaging in the last few months, and there are many changes that are not reflected in bugs closed (like most of the changes needed due to the C++11 ABI transition, bugs and problems fixed that had no report, and general rejuvenation or improvement of some parts of the code). How long this will last, I cannot know. I hope to find a job at some point, which obviously will reduce the time available to work on this. But in the meantime, for all aptitude users: Enjoy the fixes and new features! Notes [1] ^ Some visitors of the recent mini-DebConf @ Cambridge perhaps thought that the fireworks and throngs gathered were in honour of our mighty Universal Operating System, but sadly they were not. They might be, some day. In any case, the reports say that the visitors enjoyed the fireworks.

7 November 2015

Mehdi Dogguy: 3rd annual Aaron Swartz Day, November 7-8

This weekend is organized the Aaron Swartz Day across the world. There are events organized in many cities and video streams available. It is important that we remember Aaron's projects and fights. If you want to know more about Aaron Swartz, you may start by watching the excellent documentary The Internet's Own Boy : The Story of Aaron Swartz. His work was very inspirational and should not be forgotten!

8 October 2015

Petter Reinholdtsen: The Story of Aaron Swartz - Let us all weep!

The movie "The Internet's Own Boy: The Story of Aaron Swartz" is both inspiring and depressing at the same time. The work of Aaron Swartz has inspired me in my work, and I am grateful of all the improvements he was able to initiate or complete. I wish I am able to do as much good in my life as he did in his. Every minute of this 1:45 long movie is inspiring in documenting how much impact a single person can have on improving the society and this world. And it is depressing in documenting how the law enforcement of USA (and other countries) is corrupted to a point where they can push a bright kid to his death for downloading too many scientific articles. Aaron is dead. Let us all weep. The movie is also available on Youtube. I wish there were Norwegian subtitles available, so I could show it to my parents.

Petter Reinholdtsen: The Story of Aron Swartz - Let us all weep!

The movie "The Internet's Own Boy: The Story of Aaron Swartz" is both inspiring and depressing at the same time. The work of Aaron Swartz has inspired me in my work, and I am grateful of all the improvements he was able to initiate or complete. I wish I am able to do as much good in my life as he did in his. Every minute of this 1:45 long movie is inspiring in documenting how much impact a single person can have on improving the society and this world. And it is depressing in documenting how the law enforcement of USA (and other countries) is corrupted to a point where they can push a bright kid to his death for downloading too many scientific articles. Aron is dead. Let us all weep. The movie is also available on Youtube. I wish there were Norwegian subtitles available, so I could show it to my parents.

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