Search Results: "ron"

27 January 2023

Matthew Garrett: Further adventures in Apple PKCS#11 land

After my previous efforts, I wrote up a PKCS#11 module of my own that had no odd restrictions about using non-RSA keys and I tested it. And things looked much better - ssh successfully obtained the key, negotiated with the server to determine that it was present in authorized_keys, and then went to actually do the key verification step. At which point things went wrong - the Sign() method in my PKCS#11 module was never called, and a strange
debug1: identity_sign: sshkey_sign: error in libcrypto
sign_and_send_pubkey: signing failed for ECDSA "testkey": error in libcrypto"

error appeared in the ssh output. Odd. libcrypto was originally part of OpenSSL, but Apple ship the LibreSSL fork. Apple don't include the LibreSSL source in their public source repo, but do include OpenSSH. I grabbed the OpenSSH source and jumped through a whole bunch of hoops to make it build (it uses the macosx.internal SDK, which isn't publicly available, so I had to cobble together a bunch of headers from various places), and also installed upstream LibreSSL with a version number matching what Apple shipped. And everything worked - I logged into the server using a hardware-backed key.

Was the difference in OpenSSH or in LibreSSL? Telling my OpenSSH to use the system libcrypto resulted in the same failure, so it seemed pretty clear this was an issue with the Apple version of the library. The way all this works is that when OpenSSH has a challenge to sign, it calls ECDSA_do_sign(). This then calls ECDSA_do_sign_ex(), which in turn follows a function pointer to the actual signature method. By default this is a software implementation that expects to have the private key available, but you can also register your own callback that will be used instead. The OpenSSH PKCS#11 code does this by calling EC_KEY_set_method(), and as a result calling ECDSA_do_sign() ends up calling back into the PKCS#11 code that then calls into the module that communicates with the hardware and everything works.

Except it doesn't under macOS. Running under a debugger and setting a breakpoint on EC_do_sign(), I saw that we went down a code path with a function called ECDSA_do_sign_new(). This doesn't appear in any of the public source code, so seems to be an Apple-specific patch. I pushed Apple's libcrypto into Ghidra and looked at ECDSA_do_sign() and found something that approximates this:
nid = EC_GROUP_get_curve_name(curve);
if (nid == NID_X9_62_prime256v1)  
  return ECDSA_do_sign_new(dgst,dgst_len,eckey);
 
return ECDSA_do_sign_ex(dgst,dgst_len,NULL,NULL,eckey);
What this means is that if you ask ECDSA_do_sign() to sign something on a Mac, and if the key in question corresponds to the NIST P256 elliptic curve type, it goes down the ECDSA_do_sign_new() path and never calls the registered callback. This is the only key type supported by the Apple Secure Enclave, so I assume it's special-cased to do something with that. Unfortunately the consequence is that it's impossible to use a PKCS#11 module that uses Secure Enclave keys with the shipped version of OpenSSH under macOS. For now I'm working around this with an SSH agent built using Go's agent module, forwarding most requests through to the default session agent but appending hardware-backed keys and implementing signing with them, which is probably what I should have done in the first place.

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26 January 2023

Matt Brown: Goals for 2023

This is the second of a two-part post covering my goals for 2023. See the first part to understand the vision, mission and strategy driving these goals. I want to thank my friend Nat, and Will Larson whose annual reviews I ve always enjoyed reading for inspiring me to write these posts. I ve found the process articulating my motivations and goals very useful to clarify my thoughts and create tangible next steps. I m grateful for that in and of itself, but I also hope that by publishing this you too might find it interesting, and the additional public accountability it creates will be a positive encouragement to me.

2023 Goals My focus for 2023 is to bootstrap a business that I can use to build software that solves real problems (see the strategy from the previous post for more details on this). I m going to track this via three goals:
  1. Execute a series of successful consulting engagements, building a reputation for myself and leaving happy customers willing to provide testimonials that support a pipeline of future opportunities.
  2. Grow my product development skill set by taking several ideas to MVP stage with customer feedback received, and launch at least one product which generates revenue and has growth potential.
  3. Develop and maintain a broad professional network.

Consulting Based on my background and experience, I plan to target my consulting across three areas:
  1. Leadership - building and growing operationally focused software teams following SRE/devops principles. A typical engagement may involve helping a client establish a brand new SRE/devops practice, or to strengthen and mature the existing practices used to build and operate reliable software in their team(s).
  2. Architecture - applying deep technical expertise to the design of large software systems, particularly focusing on their reliability and operability. A typical engagement may involve design input and decision making support for key aspects of a new system, providing external review and analysis to improve an existing system, or delivering actionable, tactical next steps during or immediately after a reliability crisis.
  3. Technology Strategy - translating high-level business needs into a technical roadmap that provides understandable explanations of the value software can deliver in that context, and the iterative series of appropriately sized projects required to realise it. A typical customer for this would be a small to medium sized business outside of the software industry with a desire to use software in a transformative way to improve their business but who does not employ the necessary in-house expertise to lead that transition.

Product Development There are three, currently extremely high level, product ideas that I m excited to explore:
  1. Improve co-ordination of electricity resources to accelerate the electrification of NZ s energy demand and the transition to zero carbon grid. NZ has huge potential to be a world-leader in decarbonising energy use through electrification, but requires a massive transition to realise the benefits. Many of the challenges to that transition involve coordination of an order of magnitude more distributed energy resources (DER) in a much more dynamic and software-oriented manner than the electricity industry is traditionally experienced with. The concept of improving DER coordination is not novel, but our grid has unique characteristics that mean we re likely to need to build localised solutions. There is a strong match between my experience with large, high-reliability distributed software systems, and this need. With renewed motivation in the industry for rapid progress and many conversations and consultations still in their early stages this a very compelling space to explore with the intent of developing a more detailed product opportunity to pursue.
  2. Reduce agricultural emissions by making high performance farm management, including effortless compliance reporting, straightforward, fun and effective for busy farmers. NZ s commitments to reduce agricultural emissions (our largest single sector) place increased compliance and reporting burdens on busy farmers who don t want to report the same data multiple times to different regulators and authorities. In tandem, rising business costs and constraints drive a need for continuous improvements in efficiency, performance and farm management processes in order to remain profitable. This in turn drives increases in complexity and the volume of data that farmers must work with. Many industry organisations and associated software developers offer existing products aimed at addressing aspects of these problems, but anecdotal feedback indicates these are poorly integrated, piecemeal solutions that are often frustrating to use - a burden rather than a source of continuous improvement. It looks like there could be an opportunity for a delightful, comprehensive farm management and reporting system to disrupt the industry and help farmers run more profitable and sustainable farms while also reducing compliance costs and effort.
  3. Lower sickness rates and improve cognitive performance by enabling every indoor space to benefit from continuous ventilation monitoring and reporting. Indoor air quality is important in reducing disease transmission risk and promoting optimal cognitive performance, but despite the current pandemic temporarily raising its profile, a focus on indoor air quality generally remains under the radar for most people. One factor contributing to this is the lack of widely available systems for continuously monitoring and reporting on air quality. I built https://co2mon.nz/ to help address this problem in my children s school during 2022. I see potential to further grow this business through marketing and raising awareness of the value of ventilation monitoring in all indoor environments.
In addition to these mission aligned product ideas, I m also interested in exploring the creation of small to medium sized SaaS applications that deliver useful value by serving the needs of a specialised or niche business or industry. Even when not directly linked to the overall mission, the development and operation of products of this type can support the strategy. Each application adds direct revenue and also contributes to achieving better economies of scale in the many backend processes and infrastructure required to deliver secure, reliable and performant software systems.

Developing my professional network To help make this goal more actionable and measurable I will track 3 sub goals:
  1. To build a professional relationship with at least 30 new people this year, meaning that we ve met and had a decent conversation at least a couple of times and keep in touch at least every few months in some form.
  2. To publish a piece of writing on this site at least once a week, and for many of those to generate interesting conversations and feedback. I ll use this as an opportunity to explore product ideas, highlight my consulting expertise and generally contribute interesting technical content into the world.
  3. To support the growth of my local technical community by volunteering my experience and knowledge with others through activities such as mentoring, conference talks and similar.

Next Steps Over the coming weeks I ll write more about each of these topics - you can use the box in the sidebar (or on the front page, if you re on a phone) to be notified when I post new writing (there s also an RSS feed here, for the geeks). I d love to have your feedback and engagement on these goals too - please drop me an email with your thoughts or even book a meeting - it won t be a distraction to me, you ll be helping me meet my goal of developing and maintaining my network :)

Louis-Philippe V ronneau: Montreal Subway Foot Traffic Data, 2022 edition

For the fourth year in a row, I've asked Soci t de Transport de Montr al, Montreal's transit agency, for the foot traffic data of Montreal's subway. By clicking on a subway station, you'll be redirected to a graph of the station's foot traffic. Licences

Shirish Agarwal: Minidebconf Tamilnadu 2023, Tinnitus, Cooking, Books and Series.

First up is Minidebconf Tamilnadu 2023 that would be held on 28-29 January 2023. You can find rest of the details here. I do hope we get to see/hear some good stuff from the Minidebconf. Best of luck to all those who are applying.

Tinnitus During the lock-down of March 2020, I became aware of noise in ears and subsequently major hearing loss. It took me quite a while to know that Tinnitus happens to both those who have hearing loss as well as not. I keep running into threads like this and as shared by someone nobody knows what really causes it. I did try some of the apps (an app. called Resound on Android) that is supposed to tackle Tinnitus but it hasn t helped much. There is this but at least for me, right now pretty speculative. Also this, and again highly speculative.

Cooking After mum passed away, I haven t cooked anything. This used to give me pleasure but now just doesn t feel right. Cooking is something you enjoy when you are doing for somebody else and not just for yourself, at least that s how I feel and with that the curiosity to know more recipes. I do wanna buy a wok at sometime but when, how I just don t know.

Books Have been reading books quite a bit. And due to that had to again revisit and understand ISBN. Perhaps I might have shared it before. It really is something, the history of ISBN. And that co-relates with the book I read, Raising Steam by Terry Pratchett. Raising Steam is the 40th Book in the Discworld Series and it basically romanticizes and reminisces how the idea of an engine was born, and then a steam engine and how actually Railways started. There has been a lot of history and experiences from the early years of Steam Railway that have been taken and transplanted into the book. Also how Railways is and can be successful if only it is invested wisely and maintenance is done. This is only where imagination and reality come apart as maintenance isn t done and then you have issues. While this is and was in the UK, similar situation exists in India and many other places around the world and doesn t matter whether it is private or public. Exceptions are German, French but then that maybe due to Labor movements that happened and were successful unlike in other places. I could go on but then it will become a different article in itself. Suffice to say there is much to learn and you need serious people to look after it. Both in UK and India we lack that. And not just in Railways but Civil Aviation too, but again that is a story in itself.

Web-series Apart from books, have been seeing web-series that Willow is a good one that I enjoyed even though I hadn t seen the earlier movie. While there has been a flurry of movies and web-series both due to end of year and beginning of 2023 and yet have tried to be a bit partial on what I wanna watch or not. If it has crime, fantasy, drama then usually I like it. For e.g. I saw Blackout and pretty much was engrossed in what will happen next. It also does lead you to ask questions about centralization vs de-centralization for both power and other utilities and does make a case for communities to have their utilities apart from the grid as a fallback. How do we do over decades or centuries about it is a different question perhaps altogether. There were two books that kinda stood out for me, the first was Ian Rankin s Naming of the Dead . The book is about a cynical John Rebus, a man after my own heart. I am probably going to buy a few more of his series. In a way it also tells you why UK is the way it is right now. Another book that I liked was Shades of Grey by Jasper Fforde. This is one of the books that Mum would have clearly liked. It is pretty unusual while at the same time very close to 1984 and other such dystopian novels. The main trope of the book is what color you can see and how much you can see. The main character is somebody who can see Red, around the age of 20. One of the interesting aspects of the book is de-facting which closely resembles the Post-Truth world where alternative facts can be made out of air and they don t need any scientific evidence to back them up. In Jasper s world, they don t care about how things work and most of the technology is banned and curiosity is considered harmful and those who show that are murdered one way or the other. Interestingly, the author has just last year decided to start book 2 in the 3 book series that is supposed to be. This also tells why the U.S. is such a precarious situation in a way. A part of it is also due to the media which is in hands of chosen few, the same goes for UK and India, almost an oligopoly.

The Great Escape This is also a book but also about experiences of people, not in 19th-20th century but today that tells you slavery is alive and well and human-trafficking as well. This piece from NPR tells you about an MNC and Indian workers. What I found interesting is that there barely is an mention of the Indian Embassy that is supposed to help Indian people. I do know for a fact that the embassies of India has seen a drastic shortage of both people and materials even since the new Govt. came in place that was nine years ago. Incidentally, BBC shared about the Gujarat riots 2002 and that has been censored in India. They keep quiet about the UK Govt. who did find out that the Chief Minister was directly responsible for the killings and in facts his number 2, Amit Shah had shared that we would do 2002 again in the election cycle barely a month ago. But sadly, no hate speech FIR or any action was taken against Mr. Shah. There have been attempts by people to showcase the documentary. For e.g. JNU tried it and the rowdies from ABVP (arm of BJP) created violence. Even the questions that has been asked by the Wire, GOI will not acknowledge them. Interestingly, all India s edtechs have taken a beating in the last 6-8 months including the biggest BJYU s. Sharing a story from 2021 where things were best and today all of them are at bottom. In fact, the public has been wary as the prices of the courses has kept on increasing and most case studies have been found to be fake. Also the general outlook on jobs and growth has been pessimistic. In fact, most companies have been shedding jobs truckloads, most in the I.T. sector but other sectors as well. Hospitality and other related sectors have taken a huge beating, part of it post-pandemic, part of it Govt s refusal to either spend money or do any positive policies for either infrastructure, education, medical, you name it, they think private sector has all the answers which has been proven to be wrong again and again. I did not want to end on a discordant note but things are the way they are

B lint R czey: How to speed up your next build 5-20x with Firebuild?

Firebuild logo
TL;DR: Just prefix your build command (or any command) with firebuild:
firebuild <build command>
OK, but how does it work? Firebuild intercepts all processes started by the command to cache their outputs. Next time when the command or any of its descendant commands is executed with the same parameters, inputs and environment, the outputs are replayed (the command is shortcut) from the cache instead of running the command again. This is similar to how ccache and other compiler-specific caches work, but firebuild can shortcut any deterministic command, not only a specific list of compilers. Since the inputs of each command is determined at run time firebuild does not need a maintained complete dependency graph in the source like Bazel. It can work with any build system that does not implement its own caching mechanism. Determinism of commands is detected at run-time by preloading libfirebuild.so and interposing standard library calls and syscalls. If the command and all its descendants inputs are available when the command starts and all outputs can be calculated from the inputs then the command can be shortcut, otherwise it will be executed again. The interception comes with a 5-10% overhead, but rebuilds can be 5-20 times, or even faster depending on the changes between the builds. Can I try it? It is already available in Debian Unstable and Testing, Ubuntu s development release and the latest stable version is back-ported to supported Ubuntu releases via a PPA. How can I analyze my builds with firebuild? Firebuild can generate an HTML report showing each command s contribution to the build time. Below are the before and after reports of json4s, a Scala project. The command call graphs (lower ones) show that java (scalac) took 99% of the original build. Since the scalac invocations are shortcut (cutting the second build s time to less than 2% of the first one) they don t even show up in the accelerated second build s call graph. What s left to be executed again in the second run are env, perl, make and a few simple commands. The upper graphs are the process trees, with expandable nodes (in blue) also showing which command invocations were shortcut (green). Clicking on a node shows details of the command and the reason if it was not shortcut. Could I accelerate my project more? Firebuild works best for builds with CPU-intensive processes and comes with defaults to not cache very quick commands, such as sh, grep, sed, etc., because caching those would take cache space and shortcutting them may not speed up the build that much. They can still be shortcut with their parent command. Firebuild s strength is that it can find shortcutting points in the process tree automatically, e.g. from sh -c 'bash -c "sh -c echo Hello World!"' bash would be shortcut, but none of the sh commands would be cached. In typical builds there are many such commands from the skip_cache list. Caching those commands with firebuild -o 'processes.skip_cache = []' can improve acceleration and make the reports smaller. Firebuild also supports several debug flags and -d proc helps finding reasons for not shortcutting some commands:
...
FIREBUILD: Command "/usr/bin/make" can't be short-cut due to: Executable set to be not shortcut,  ExecedProcess 1329.2, running, "make -f debian/rules build", fds=[ FileFD fd=0  FileOFD ...
FIREBUILD: Command "/usr/bin/sort" can't be short-cut due to: Process read from inherited fd ,  ExecedProcess 4161.1, running, "sort", fds=[ FileFD fd=0  FileOFD ...
FIREBUILD: Command "/usr/bin/find" can't be short-cut due to: fstatfs() family operating on fds is not supported,  ExecedProcess 1360.1, running, "find -mindepth 1 ...
...
make, ninja and other incremental build tool binaries are not shortcut because they compare the timestamp of files, but they are fast at least and every build step they perform can still be shortcut. Ideally the slower build steps that could not be shortcut can be re-implemented in ways that can be shortcut by avoiding tools performing unsupported operations. I hope those tools help speeding up your build with very little effort, but if not and you find something to fix or improve in firebuild itself, please report it or just leave a feedback! Happy speeding, but not on public roads!

Matt Brown: Vision, Mission and Strategy

This is the first of a two-part post, covering high-level thoughts around my motivations and vision. Make sure to check out the second part for my specific goals for 2023. A new year is upon us! My plan was to be 6 months into the journey of starting a business by this point. I made some very tentative progress towards that goal in 2022, registering a company and starting some consulting work, but on the whole I ve found it much harder than expected to gather the necessary energy to begin that journey in earnest.

Reflection I m excited about the next chapter of my career, so the fact that I ve been struggling to get started has been frustrating. The only upside is that the delay has given me plenty of time to reflect on the last few years and what I can learn from them and draw some lessons to help better manage and sustain my energy going forward.

Purpose A large part of what I ve realised is that I should have left Google years ago. It was a great place to work, and I m incredibly grateful for everything I learned and received during my time there. For years it was my dream job, but my happiness had been declining, and instead of taking the (relatively small) risk of leaving to the unknown, I tried several variations of team and role in the hope of restoring the dream. The reality is that a significant chunk of my motivation and energy comes from being able to link my work back to a bigger purpose that delivers concrete positive impact in the world. I felt that link through Google s mission to make information universally accessible and useful for the first 10-11 years, but for the latter 4-5 years my ability to see that link was tenuous at best and trying to push through the challenges presented without that link providing a reliable source of energy is what drove my unhappiness and led to needing a longer break to recharge. I expect the challenges of starting a business to be even greater than what I experienced at Google, so the lesson I m taking from this is that it s crucial for me to understand what the link between my work and the bigger purpose with concrete positive impact in the world that I m aiming to contribute to is.

Community The second factor that I ve slowly come to realise has been missing from my career in the last few years has been participation in a professional community and a variety of enriching interpersonal relationships. As much as I value and need this type of interaction, fostering and sustaining it unfortunately doesn t come naturally to me. Working remotely since 2016 and then taking a 9 month break out of the industry are not particularly helpful contributors to building and maintaining a wide network either! The lesson here is simply that I m going to need to push past my comfort zone in reaching out and introducing myself to a range of people in order to grow my professional network, and equally I need to be diligent and disciplined in making time to maintain and regularly connect with people whom I respect and find energising to interact with.

Personal Influences Lastly, I ve been reflecting on a set of principles that are important to me. These are not so much new lessons, more confirming to myself what I value moving forward. There are many things I could include here, but to keep it somewhat brief, the key influences on my thinking are:
  • Independence - I can t entirely explain why or where it comes from, but since the start of my professional career (which I consider to be my consulting/freelancing development during high school) I ve understood that I m far more motivated by building and growing my own business than I am by working for someone else. Working for myself has always felt like the default and sensible course - I m excited to get back to that.
  • Openness - Open is better than closed, in terms of software, business model and organisational processes. This continues to be a strong belief and something I want to uphold in my business endeavours. Competition should be based on superior technical quality or service, not artificial constraints or barriers to entry that lock customers and users into a single solution or market. Protocols and networks should be open for wide participation and easily accessible to new entrants and competition.
  • People first - This applies both to how we work with each other - respectfully, valuing diversity and with integrity, and to how we apply technology to our world - with consideration for all stakeholders it may affect and awareness of both the intended and potential unintended impacts.

Framework Using Vision, Mission and Strategy as a planning framework has worked quite well for me when building and growing teams over the years, so I plan to re-use it personally to help organise the above reflections into a hopefully cohesive plan than results in some useful 2023 goals.

Vision Software systems contribute direct and meaningful impact to solving real problems in our world. Each word has a fair bit of meaning behind it for me, so breaking it down a little bit:
  • software systems - excite me because software is eating the world and has significant potential to do good.
  • contribute - Software alone doesn t solve problems, and misapplied can easily make things worse. To contribute software needs to be designed intentionally and evaluated with an awareness of risks it could pose within the complex system that is our modern world.
  • direct and meaningful impact - I m not looking for broad outcomes like improving productivity or communication, which apply generally across many problems. I want to see software applied to solve specific blockers whose removal unlocks significant progress towards solving a problem.
  • real - as opposed to straightforward problems. The types of issue where the acknowledgement of it as a real problem often ends the sentence as it feels too big to tackle. Climate change and pandemic risk are examples of real problems. Decentralising finance or selling more widgets are not.
  • in our world - is mostly filler to round out the sentence nicely, but I do think we should probably sort out the mess we re making on our own planet before trying to colonise anywhere else.

Mission To lead the development and operation of software systems that deliver new opportunities for individuals, businesses and communities to solve the real problems in their community. Again breaking down the intent a little bit:
  • lead - having a meaningful impact on real problems is a big job. I won t succeed as a one man band. It will require building and growing a larger team.
  • development and operation - development is fun and necessary, but I also wanted to highlight that the ongoing operation and integration of those software systems into the broader social and human systems of our world is an equally important and ongoing need.
  • new opportunities - are important to drive and motivate investment in the adoption of technology. Building or operating a system that maintains the status quo is not motivating for me.
  • individuals, businesses and communities - aka everyone! But each of these groups (as examples, not specific) will have diverse roles, needs and interactions with the software which must be considered to ensure the system achieves the desired contribution and impact.
  • their community - refines the ambition from the vision to an achievable scope of action within which to execute the mission. We won t solve our problems by targeting one big global fix, but if we each participate in solving the problems in our community, collectively it will make a difference.

Strategy Build a sustainable business that provides a home and infrastructure to support a continuous cycle of development, validation and growth of software systems fulfilling the mission and vision above.
  • Accumulate meaningful impact via a portfolio of systems rather than one big bet.
  • Focus on opportunities that promote the decarbonisation of our economy (the most pressing problem our society faces), but not at the expense of ignoring compelling opportunities to contribute impact to other real problems also.
  • Favour the marathon over the sprint - while being first can be fun and convey benefits, it s often the fast-followers who learn from the initial mistakes and deliver lasting change and broader impact.
In keeping with the final bullet point, I aim to evaluate the strategy against a long-term view of success. What excites me about it is that it has the potential to provide structure and clarity for my work while also enabling many future paths - from operating a portfolio of micro-SaaS products that each solve real problems for a specific niche or community, or diving deep into a single compelling opportunity for a year or two, joining with others to partner on shared ventures or some combination of all three and other variations in between.

Your Thoughts I consider this a first draft, which I intend to revise and evolve further over the next 6-12 months. I don t plan major changes to the intent or underlying ideas, but finding the best words to express and convey that intent clearly is not something I expect to get right on the first take. I d love to have your feedback and engagement as I move forward with this strategy - please use the box in the sidebar (or on the front page, if you re on a phone) to be notified when I post new writing, drop me an email with your thoughts or even book a meeting to say hi and discuss something in detail.

Goals for 2023 Next up - check out part two of this post to see my goals for 2023.

Dirk Eddelbuettel: RcppTOML 0.2.1 on CRAN: Small Build Fix for Some Arches

Two weeks after the release of RcppTOML 0.2.0 and the switch to toml++, we have a quick bugfix release 0.2.1. TOML is a file format that is most suitable for configurations, as it is meant to be edited by humans but read by computers. It emphasizes strong readability for humans while at the same time supporting strong typing as well as immediate and clear error reports. On small typos you get parse errors, rather than silently corrupted garbage. Much preferable to any and all of XML, JSON or YAML though sadly these may be too ubiquitous now. TOML is frequently being used with the projects such as the Hugo static blog compiler, or the Cargo system of Crates (aka packages ) for the Rust language. Some architectures, aarch64 included, got confused over float16 which is of course a tiny two-byte type nobody should need. After consulting with Mark we concluded to (at least for now) simply override this excluding the use of float16 . The short summary of changes follows.

Changes in version 0.2.1 (2023-01-25)
  • Explicitly set -DTOML_ENABLE_FLOAT16=0 to permit compilation on some architectures stumbling of the type.

Courtesy of my CRANberries, there is a diffstat report for this release. More information is on the RcppTOML page page. Please use the GitHub issue tracker for issues and bugreports. If you like this or other open-source work I do, you can sponsor me at GitHub.

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

22 January 2023

Dirk Eddelbuettel: Rcpp 1.0.10 on CRAN: Regular Update

rcpp logo The Rcpp team is thrilled to announce the newest release 1.0.10 of the Rcpp package which is hitting CRAN now and will go to Debian shortly. Windows and macOS builds should appear at CRAN in the next few days, as will builds in different Linux distribution and of course at r2u. The release was prepared a few days ago, but given the widespread use at CRAN it took a few days to be processed. As always, our sincere thanks to the CRAN maintainers Uwe Ligges and Kurt Hornik. This release continues with the six-months cycle started with release 1.0.5 in July 2020. As a reminder, we do of course make interim snapshot dev or rc releases available via the Rcpp drat repo and strongly encourage their use and testing I run my systems with these versions which tend to work just as well, and are also fully tested against all reverse-dependencies. Rcpp has become the most popular way of enhancing R with C or C++ code. Right now, around 2623 packages on CRAN depend on Rcpp for making analytical code go faster and further, along with 252 in BioConductor. On CRAN, 13.7% of all packages depend (directly) on CRAN, and 58.7% of all compiled packages do. From the cloud mirror of CRAN (which is but a subset of all CRAN downloads), Rcpp has been downloaded 67.1 million times. This release is incremental as usual, preserving existing capabilities faithfully while smoothing our corners and / or extending slightly. Of particular note is the now fully-enabled use of the unwind protection making some operations a little faster by default; special thanks to I aki for spearheading this. Kevin and I also polished a few other bugs off as detailed below. The full list of details follows.

Changes in Rcpp release version 1.0.10 (2023-01-12)
  • Changes in Rcpp API:
    • Unwind protection is enabled by default (I aki in #1225). It can be disabled by defining RCPP_NO_UNWIND_PROTECT before including Rcpp.h. RCPP_USE_UNWIND_PROTECT is not checked anymore and has no effect. The associated plugin unwindProtect is therefore deprecated and will be removed in a future release.
    • The 'finalize' method for Rcpp Modules is now eagerly materialized, fixing an issue where errors can occur when Module finalizers are run (Kevin in #1231 closing #1230).
    • Zero-row data.frame objects can receive push_back or push_front (Dirk in #1233 fixing #1232).
    • One remaining sprintf has been replaced by snprintf (Dirk and Kevin in #1236 and #1237).
    • Several conversion warnings found by clang++ have been addressed (Dirk in #1240 and #1241).
  • Changes in Rcpp Attributes:
    • The C++20, C++2b (experimental) and C++23 standards now have plugin support like the other C++ standards (Dirk in #1228).
    • The source path for attributes received one more protection from spaces (Dirk in #1235 addressing #1234).
  • Changes in Rcpp Deployment:
    • Several GitHub Actions have been updated.

Thanks to my CRANberries, you can also look at a diff to the previous release. Questions, comments etc should go to the rcpp-devel mailing list off the R-Forge page. Bugs reports are welcome at the GitHub issue tracker as well (where one can also search among open or closed issues); questions are also welcome under rcpp tag at StackOverflow which also allows searching among the (currently) 2932 previous questions. If you like this or other open-source work I do, you can sponsor me at GitHub.

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

18 January 2023

Jonathan Dowland: Belfast (David Holmes Remix)

This morning s record to start the day is David Holmes s remix of Belfast , by Orbital: the latest cover mount record with Electronic Sound magazine. This, and several other new remixes are available on the recent compilation 30 Something which, despite being yet another comp, I ve found quite compelling.
picture of a vinyl record
An unusual decision by ES: they ve split the remix across both sides, but kept the RPM at 45. I haven t ran the numbers to figure out if they could have fit it on one side at 33, but even if they could perhaps it would be too compromised. Quite a trade-off with splitting the track! Orbital are embarking on a new UK tour soon and play Newcastle in March. They ve got a new album out in February.

Matthew Garrett: PKCS#11. hardware keystores, and Apple frustrations

There's a bunch of ways you can store cryptographic keys. The most obvious is to just stick them on disk, but that has the downside that anyone with access to the system could just steal them and do whatever they wanted with them. At the far end of the scale you have Hardware Security Modules (HSMs), hardware devices that are specially designed to self destruct if you try to take them apart and extract the keys, and which will generate an audit trail of every key operation. In between you have things like smartcards, TPMs, Yubikeys, and other platform secure enclaves - devices that don't allow arbitrary access to keys, but which don't offer the same level of assurance as an actual HSM (and are, as a result, orders of magnitude cheaper).

The problem with all of these hardware approaches is that they have entirely different communication mechanisms. The industry realised this wasn't ideal, and in 1994 RSA released version 1 of the PKCS#11 specification. This defines a C interface with a single entry point - C_GetFunctionList. Applications call this and are given a structure containing function pointers, with each entry corresponding to a PKCS#11 function. The application can then simply call the appropriate function pointer to trigger the desired functionality, such as "Tell me how many keys you have" and "Sign this, please". This is both an example of C not just being a programming language and also of you having to shove a bunch of vendor-supplied code into your security critical tooling, but what could possibly go wrong.

(Linux distros work around this problem by using p11-kit, which is a daemon that speaks d-bus and loads PKCS#11 modules for you. You can either speak to it directly over d-bus, or for apps that only speak PKCS#11 you can load a module that just transports the PKCS#11 commands over d-bus. This moves the weird vendor C code out of process, and also means you can deal with these modules without having to speak the C ABI, so everyone wins)

One of my work tasks at the moment is helping secure SSH keys, ensuring that they're only issued to appropriate machines and can't be stolen afterwards. For Windows and Linux machines we can stick them in the TPM, but Macs don't have a TPM as such. Instead, there's the Secure Enclave - part of the T2 security chip on x86 Macs, and directly integrated into the M-series SoCs. It doesn't have anywhere near as many features as a TPM, let alone an HSM, but it can generate NIST curve elliptic curve keys and sign things with them and that's good enough. Things are made more complicated by Apple only allowing keys to be used by the app that generated them, so it's hard for applications to generate keys on behalf of each other. This can be mitigated by using CryptoTokenKit, an interface that allows apps to present tokens to the systemwide keychain. Although this is intended for allowing a generic interface for access to such tokens (kind of like PKCS#11), an app can generate its own keys in the Secure Enclave and then expose them to other apps via the keychain through CryptoTokenKit.

Of course, applications then need to know how to communicate with the keychain. Browsers mostly do so, and Apple's version of SSH can to an extent. Unfortunately, that extent is "Retrieve passwords to unlock on-disk keys", which doesn't help in our case. PKCS#11 comes to the rescue here! Apple ship a module called ssh-keychain.dylib, a PKCS#11 module that's intended to allow SSH to use keys that are present in the system keychain. Unfortunately it's not super well maintained - it got broken when Big Sur moved all the system libraries into a cache, but got fixed up a few releases later. Unfortunately every time I tested it with our CryptoTokenKit provider (and also when I retried with SecureEnclaveToken to make sure it wasn't just our code being broken), ssh would tell me "provider /usr/lib/ssh-keychain.dylib returned no slots" which is not especially helpful. Finally I realised that it was actually generating more debug output, but it was being sent to the system debug logs rather than the ssh debug output. Well, when I say "more debug output", I mean "Certificate []: algorithm is not supported, ignoring it", which still doesn't tell me all that much. So I stuck it in Ghidra and searched for that string, and the line above it was

iVar2 = __auth_stubs::_objc_msgSend(uVar7,"isEqual:",*(undefined8*)__got::_kSecAttrKeyTypeRSA);

with it immediately failing if the key isn't RSA. Which it isn't, since the Secure Enclave doesn't support RSA. Apple's PKCS#11 module appears incapable of making use of keys generated on Apple's hardware.

There's a couple of ways of dealing with this. The first, which is taken by projects like Secretive, is to implement the SSH agent protocol and have SSH delegate key management to that agent, which can then speak to the keychain. But if you want this to work in all cases you need to implement all the functionality in the existing ssh-agent, and that seems like a bunch of work. The second is to implement a PKCS#11 module, which sounds like less work but probably more mental anguish. I'll figure that out tomorrow.

comment count unavailable comments

Russ Allbery: Review: Forward

Review: Forward, edited by Blake Crouch
Publisher: Amazon Original Stories
Copyright: September 2019
ISBN: 1-5420-9206-X
ISBN: 1-5420-4363-8
ISBN: 1-5420-9357-0
ISBN: 1-5420-0434-9
ISBN: 1-5420-4363-8
ISBN: 1-5420-4425-1
Format: Kindle
Pages: 300
This is another Amazon collection of short fiction, this time mostly at novelette length. (The longer ones might creep into novella.) As before, each one is available separately for purchase or Amazon Prime "borrowing," with separate ISBNs. The sidebar cover is for the first in the sequence. (At some point I need to update my page templates so that I can add multiple covers.) N.K. Jemisin's "Emergency Skin" won the 2020 Hugo Award for Best Novelette, so I wanted to read and review it, but it would be too short for a standalone review. I therefore decided to read the whole collection and review it as an anthology. This was a mistake. Learn from my mistake. The overall theme of the collection is technological advance, rapid change, and the ethical and social question of whether we should slow technology because of social risk. Some of the stories stick to that theme more closely than others. Jemisin's story mostly ignores it, which was probably the right decision. "Ark" by Veronica Roth: A planet-killing asteroid has been on its inexorable way towards Earth for decades. Most of the planet has been evacuated. A small group has stayed behind, cataloging samples and filling two remaining ships with as much biodiversity as they can find with the intent to leave at the last minute. Against that backdrop, two of that team bond over orchids. If you were going "wait, what?" about the successful evacuation of Earth, yeah, me too. No hint is offered as to how this was accomplished. Also, the entirety of humanity abandoned mutual hostility and national borders to cooperate in the face of the incoming disaster, which is, uh, bizarrely optimistic for an otherwise gloomy story. I should be careful about how negative I am about this story because I am sure it will be someone's favorite. I can even write part of the positive review: an elegiac look at loss, choices, and the meaning of a life, a moving look at how people cope with despair. The writing is fine, the story structure works; it's not a bad story. I just found it monumentally depressing, and was not engrossed by the emotionally abused protagonist's unresolved father issues. I can imagine a story around the same facts and plot that I would have liked much better, but all of these people need therapy and better coping mechanisms. I'm also not sure what this had to do with the theme, given that the incoming asteroid is random chance and has nothing to do with technological development. (4) "Summer Frost" by Blake Crouch: The best part of this story is the introductory sequence before the reader knows what's going on, which is full of evocative descriptions. I'm about to spoil what is going on, so if you want to enjoy that untainted by the stupidity of the rest of the plot, skip the rest of this story review. We're going to have a glut of stories about the weird and obsessive form of AI risk invented by the fevered imaginations of the "rationalist" community, aren't we. I don't know why I didn't predict that. It's going to be just as annoying as the glut of cyberpunk novels written by people who don't understand computers. Crouch lost me as soon as the setup is revealed. Even if I believed that a game company would use a deep learning AI still in learning mode to run an NPC (I don't; see Microsoft's Tay for an obvious reason why not), or that such an NPC would spontaneously start testing the boundaries of the game world (this is not how deep learning works), Crouch asks the reader to believe that this AI started as a fully scripted NPC in the prologue with a fixed storyline. In other words, the foundation of the story is that this game company used an AI model capable of becoming a general intelligence for barely more than a cut scene. This is not how anything works. The rest of the story is yet another variation on a science fiction plot so old and threadbare that Isaac Asimov invented the Three Laws of Robotics to avoid telling more versions of it. Crouch's contribution is to dress it up in the terminology of the excessively online. (The middle of the story features a detailed discussion of Roko's basilisk; if you recognize that, you know what you're in for.) Asimov would not have had a lesbian protagonist, so points for progress I guess, but the AI becomes more interesting to the protagonist than her wife and kid because of course it does. There are a few twists and turns along the way, but the destination is the bog-standard hard-takeoff general intelligence scenario. One more pet peeve: Authors, stop trying to illustrate the growth of your AI by having it move from broken to fluent English. English grammar is so much easier than self-awareness or the Turing test that we had programs that could critique your grammar decades before we had believable chatbots. It's going to get grammar right long before the content of the words makes any sense. Also, your AI doesn't sound dumber, your AI sounds like someone whose native language doesn't use pronouns and helper verbs the way that English does, and your decision to use that as a marker for intelligence is, uh, maybe something you should think about. (3) "Emergency Skin" by N.K. Jemisin: The protagonist is a heavily-augmented cyborg from a colony of Earth's diaspora. The founders of that colony fled Earth when it became obvious to them that the planet was dying. They have survived in another star system, but they need a specific piece of technology from the dead remnants of Earth. The protagonist has been sent to retrieve it. The twist is that this story is told in the second-person perspective by the protagonist's ride-along AI, created from a consensus model of the rulers of the colony. We never see directly what the protagonist is doing or thinking, only the AI reaction to it. This is exactly the sort of gimmick that works much better in short fiction than at novel length. Jemisin uses it to create tension between the reader and the narrator, and I thoroughly enjoyed the effect. (As shown in the Broken Earth trilogy, Jemisin is one of the few writers who can use second-person effectively.) I won't spoil the revelation, but it's barbed and biting and vicious and I loved it. Jemisin does deliver the point with a sledgehammer, so be aware of that if you want subtlety in your short fiction, but I prefer the bluntness. (This is part of why I usually don't get along with literary short stories.) The reader of course can't change the direction of the story, but the second-person perspective still provides a hit of vicarious satisfaction. I can see why this won the Hugo; it's worth seeking out. (8) "You Have Arrived at Your Destination" by Amor Towles: Sam and his wife are having a child, and they've decided to provide him with an early boost in life. Vitek is a fertility lab, but more than that, it can do some gene tweaking and adjustment to push a child more towards one personality or another. Sam and his wife have spent hours filling out profiles, and his wife spent hours weeding possible choices down to three. Now, Sam has come to Vitek to pick from the remaining options. Speaking of literary short stories, Towles is the non-SFF writer of this bunch, and it's immediately obvious. The story requires the SFnal premise, but after that this is a character piece. Vitek is an elite, expensive company with a condescending and overly-reductive attitude towards humanity, which is entirely intentional on the author's part. This is the sort of story that gets resolved in an unexpected conversation in a roadside bar, and where most of the conflict happens inside the protagonist's head. I was initially going to complain that Towles does the standard literary thing of leaving off the denouement on the grounds that the reader can figure it out, but when I did a bit of re-reading for this review, I found more of the bones than I had noticed the first time. There's enough subtlety that I had to think for a bit and re-read a passage, but not too much. It's also the most thoughtful treatment of the theme of the collection, the only one that I thought truly wrestled with the weird interactions between technological capability and human foresight. Next to "Emergency Skin," this was the best story of the collection. (7) "The Last Conversation" by Paul Tremblay: A man wakes up in a dark room, in considerable pain, not remembering anything about his life. His only contact with the world at first is a voice: a woman who is helping him recover his strength and his memory. The numbers that head the chapters have significant gaps, representing days left out of the story, as he pieces together what has happened alongside the reader. Tremblay is the horror writer of the collection, so predictably this is the story whose craft I can admire without really liking it. In this case, the horror comes mostly from the pacing of revelation, created by the choice of point of view. (This would be a much different story from the perspective of the woman.) It's well-done, but it has the tendency I've noticed in other horror stories of being a tightly closed system. I see where the connection to the theme is, but it's entirely in the setting, not in the shape of the story. Not my thing, but I can see why it might be someone else's. (5) "Randomize" by Andy Weir: Gah, this was so bad. First, and somewhat expectedly, it's a clunky throwback to a 1950s-style hard SF puzzle story. The writing is atrocious: wooden, awkward, cliched, and full of gratuitous infodumping. The characterization is almost entirely through broad stereotypes; the lone exception is the female character, who at least adds an interesting twist despite being forced to act like an idiot because of the plot. It's a very old-school type of single-twist story, but the ending is completely implausible and falls apart if you breathe on it too hard. Weir is something of a throwback to an earlier era of scientific puzzle stories, though, so maybe one is inclined to give him a break on the writing quality. (I am not; one of the ways in which science fiction has improved is that you can get good scientific puzzles and good writing these days.) But the science is also so bad that I was literally facepalming while reading it. The premise of this story is that quantum computers are commercially available. That will cause a serious problem for Las Vegas casinos, because the generator for keno numbers is vulnerable to quantum algorithms. The solution proposed by the IT person for the casino? A quantum random number generator. (The words "fight quantum with quantum" appear literally in the text if you're wondering how bad the writing is.) You could convince me that an ancient keno system is using a pseudorandom number generator that might be vulnerable to some quantum algorithm and doesn't get reseeded often enough. Fine. And yes, quantum computers can be used to generate high-quality sources of random numbers. But this solution to the problem makes no sense whatsoever. It's like swatting a house fly with a nuclear weapon. Weir says explicitly in the story that all the keno system needs is an external source of high-quality random numbers. The next step is to go to Amazon and buy a hardware random number generator. If you want to splurge, it might cost you $250. Problem solved. Yes, hardware random number generators have various limitations that may cause you problems if you need millions of bits or you need them very quickly, but not for something as dead-simple and with such low entropy requirements as keno numbers! You need a trivial number of bits for each round; even the slowest and most conservative hardware random number generator would be fine. Hell, measure the noise levels on the casino floor. Point a camera at a lava lamp. Or just buy one of the physical ball machines they use for the lottery. This problem is heavily researched, by casinos in particular, and is not significantly changed by the availability of quantum computers, at least for applications such as keno where the generator can be reseeded before each generation. You could maybe argue that this is an excuse for the IT guy to get his hands on a quantum computer, which fits the stereotypes, but that still breaks the story for reasons that would be spoilers. As soon as any other casino thought about this, they'd laugh in the face of the characters. I don't want to make too much of this, since anyone can write one bad story, but this story was dire at every level. I still owe Weir a proper chance at novel length, but I can't say this added to my enthusiasm. (2) Rating: 4 out of 10

Arnaud Rebillout: Build container images in GitLab CI (iptables-legacy at the rescue)

It's 2023 and these days, building a container image in a CI pipeline should be straightforward. So let's try. For this blog post we'll focus on GitLab SaaS only, that is, gitlab.com, as it's what I use for work and for personal projects. To get started, we just need two files in our Git repository: Here is our Git tree:
$ ls -A
Containerfile  .git  .gitlab-ci.yml
$ cat Containerfile 
FROM debian:stable
RUN  apt-get update
CMD  echo hello world
$ cat .gitlab-ci.yml 
build-container-image:
  stage: build
  image: debian:testing
  before_script:
    - apt-get update
    - apt-get install -y buildah ca-certificates
  script:
    - buildah build -t $CI_REGISTRY_IMAGE .
    - buildah login -u $CI_REGISTRY_USER -p $CI_JOB_TOKEN $CI_REGISTRY
    - buildah push $CI_REGISTRY_IMAGE
A few remarks: Now let's push that. Does the CI pass? No, of course, otherwise I wouldn't be writing this blog post ;) The CI fails at the buildah build command, with a rather cryptic error:
$ buildah build --tag $CI_REGISTRY_IMAGE .
[...]
STEP 2/3: RUN  apt-get update
error running container: did not get container start message from parent: EOF
Error: building at STEP "RUN apt-get update": netavark: code: 4, msg: iptables v1.8.8 (nf_tables): Could not fetch rule set generation id: Invalid argument
The hint here is nf_tables... Back in July 2021, GitLab did a major update of their shared runners infrastructure, and broke nftables support in the process, as it seems. So we have to use iptables instead. Let's fix our .gitlab-ci.yml, which now looks like that:
$ cat .gitlab-ci.yml 
build-container-image:
  stage: build
  image: debian:testing
  before_script:
    - apt-get update
    - apt-get install -y buildah ca-certificates
    -  
      # Switch to iptables legacy, as GitLab CI doesn't support nftables.
      apt-get install -y --no-install-recommends iptables
      update-alternatives --set iptables /usr/sbin/iptables-legacy
  script:
    - buildah build -t $CI_REGISTRY_IMAGE .
    - buildah login -u $CI_REGISTRY_USER -p $CI_JOB_TOKEN $CI_REGISTRY
    - buildah push $CI_REGISTRY_IMAGE
And push again. Does that work? Yes! If you're interested in this issue, feel free to fork https://gitlab.com/arnaudr/gitlab-build-container-image and try it by yourself. It's been more than a year since this change, and I'm surprised that I didn't find much about it on the Internet, neither mentions of the issue, nor of a workaround. Maybe nobody builds container images in GitLab CI, or maybe they do it another way, I don't know. In any case, now it's documented in this blog, hopefully some will find it useful. Happy 2023!

16 January 2023

Gunnar Wolf: Back to Understanding Computers and Cognition

As many of you know, I work at UNAM, Mexico s largest university. My work is split in two parts: My full-time job is to be the systems and network administrator at the Economics Research Institute, and I do some hours of teaching at the Engineering Faculty. At the Institute, my role is academic but although I have tried to frame my works in a way amenable to analysis grounded on the Social Sciences (Construcci n Colaborativa del Conocimiento, Hecho con Creative Commons, Mecanismos de privacidad y anonimato), so far, I have not taken part of academic collaboration with my coworkers Economics is a field very far from my interests, to somehow illustrate it. I was very happy when I was invited to be a part of a Seminar on The Digital Economy in the age of Artificial Intelligence . I talked with the coordinator, and we agreed we have many Economic Science experts but understanding what does Artificial Intelligence mean eludes then, so I will be writing one of the introductory chapters to this analysis. But Hey, I m no expert in Artificial Intelligence. If anything, I could be categorized as an AI-skeptical! Well, at least I might be the closest thing at hand in the Institute So I have been thinking about what I will be writing, and finding and reading material to substantiate what I ll be writing. One of the readings I determined early on I would be going back to is Terry Winograd and Fernando Flores 1986 book, Understanding Computers and Cognition: A New Foundation for Design (oh, were you expecting a link to buy it instead of reading it online?) I first came across this book by mere chance. Back in the last day of year 2000, my friend Ariel invited me and my then-girlfriend to tag along and travel by land to the USA to catch some just-after-Christmas deals in San Antonio. I was not into shopping, but have always enjoyed road trips, so we went together. We went, yes, to the never-ending clothing shops, but we also went to some big libraries And the money I didn t spend at other shops, I spent there. And then some more. There was a little, somewhat oldish book that caught my eye. And I ll be honest: I looked at this book only because it was obviously produced by the LaTeX typesetting system (the basics of which I learnt in 1983, and with which I have written well, basically everything substantial I ve ever done). I remember I read this book with most interest back in that year, and finished it with a Wow, that was a strange trip! And Although I have never done much that could be considered AI-related, this has always been my main reference. But not for explaining what is a perceptron, how is an expert system to ponder the weight of given information, or whether a neural network is convolutional or recurrent, or how to turn from a network trained to recognize feature x into a generational network. No, our book is not technical. Well Not in that sense. This book tackles cognition. But in order to discuss cognition, it must first come to a proper definition of it. And to do so, it has to base itself on philosophy, starting by noting the author s disagreement with what they term as the rationalistic tradition: what we have come to term valid reasoning in Western countries. Their main claim is that the rationalistic tradition cannot properly explain a process as complex as cognition (how much bolder can you be than proposing something like this?). So, this book presents many constructs of Heidggerian origin, aiming to explain what it is understanding and being. In doing so, it follows Humberto Maturana s work. Maturana is also a philosopher, but comes from a background in biology he published works on animal neurophysiology that are also presented here. Writing this, I must ensure you I am not a philosopher, and lack field-specific knowledge to know whether this book is so unique. I know from the onset it does not directly help me to write the chapter I will be writing (but it will surely help me write some important caveats that will make the chapter much more interesting and different to what anybody with a Web browser could write about artificial intelligence). One last note: Although very well written, and notable for bringing hard to grasp concepts to mere technical staff as myself, this is not light, easy reading. I started re-reading this book a couple of weeks ago, and have just finished chapter 5 (page 69). As some reviewers state, this is one of those books you have to go back a paragraph or two over and over. But it is a most enjoyable and interesting reading.

Russ Allbery: Review: The Truth

Review: The Truth, by Terry Pratchett
Series: Discworld #25
Publisher: Harper
Copyright: November 2000
Printing: August 2014
ISBN: 0-06-230736-3
Format: Mass market
Pages: 435
The Truth is the 25th Discworld novel. Some reading order guides group it loosely into an "industrial revolution" sequence following Moving Pictures, but while there are thematic similarities I'll talk about in a moment, there's no real plot continuity. You could arguably start reading Discworld here, although you'd be spoiled for some character developments in the early Watch novels. William de Worde is paid to write a newsletter. That's not precisely what he calls it, and it's not clear whether his patrons know that he publishes it that way. He's paid to report on news of Ankh-Morpork that may be of interest of various rich or influential people who are not in Ankh-Morpork, and he discovered the best way to optimize this was to write a template of the newsletter, bring it to an engraver to make a plate of it, and run off copies for each of his customers, with some minor hand-written customization. It's a comfortable living for the estranged younger son of a wealthy noble. As the story opens, William is dutifully recording the rumor that dwarfs have discovered how to turn lead into gold. The rumor is true, although not in the way that one might initially assume.
The world is made up of four elements: Earth, Air, Fire, and Water. This is a fact well known even to Corporal Nobbs. It's also wrong. There's a fifth element, and generally it's called Surprise. For example, the dwarfs found out how to turn lead into gold by doing it the hard way. The difference between that and the easy way is that the hard way works.
The dwarfs used the lead to make a movable type printing press, which is about to turn William de Worde's small-scale, hand-crafted newsletter into a newspaper. The movable type printing press is not unknown technology. It's banned technology, because the powers that be in Ankh-Morpork know enough to be deeply suspicious of it. The religious establishment doesn't like it because words are too important and powerful to automate. The nobles and the Watch don't like it because cheap words cause problems. And the engraver's guild doesn't like it for obvious reasons. However, Lord Vetinari knows that one cannot apply brakes to a volcano, and commerce with the dwarfs is very important to the city. The dwarfs can continue. At least for now. As in Moving Pictures, most of The Truth is an idiosyncratic speedrun of the social effects of a new technology, this time newspapers. William has no grand plan; he's just an observant man who likes to write, cares a lot about the truth, and accidentally stumbles into editing a newspaper. (This, plus being an estranged son of a rich family, feels very on-point for journalism.) His naive belief is that people want to read true things, since that's what his original patrons wanted. Truth, however, may not be in the top five things people want from a newspaper. This setup requires some narrative force to push it along, which is provided by a plot to depose Vetinari by framing him for murder. The most interesting part of that story is Mr. Pin and Mr. Tulip, the people hired to do the framing and then dispose of the evidence. They're a classic villain type: the brains and the brawn, dangerous, terrifying, and willing to do horrible things to people. But one thing Pratchett excels at is taking a standard character type, turning it a bit sideways, and stuffing in things that one wouldn't think would belong. In this case, that's Mr. Tulip's deep appreciation for, and genius grasp of, fine art. It should not work to have the looming, awful person with anger issues be able to identify the exact heritage of every sculpture and fine piece of goldsmithing, and yet somehow it does. Also as in Moving Pictures (and, in a different way, Soul Music), Pratchett tends to anthropomorphize technology, giving it a life and motivations of its own. In this case, that's William's growing perception of the press as an insatiable maw into which one has to feed words. I'm usually dubious of shifting agency from humans to things when doing social analysis (and there's a lot of social analysis here), but I have to concede that Pratchett captures something deeply true about the experience of feedback loops with an audience. A lot of what Pratchett puts into this book about the problematic relationship between a popular press and the truth is obvious and familiar, but he also makes some subtle points about the way the medium shapes what people expect from it and how people produce content for it that are worthy of Marshall McLuhan. The interactions between William and the Watch were less satisfying. In our world, the US press is, with only rare exceptions, a thoughtless PR organ for police propaganda and the exonerative tense. Pratchett tackles that here... sort of. William vaguely grasps that his job as a reporter may be contrary to the job of the Watch to maintain order, and Vimes's ambivalent feelings towards "solving crimes" push the story in that direction. But this is also Vimes, who is clearly established as one of the good sort and therefore is a bad vehicle for talking about how the police corrupt the press. Pratchett has Vimes and Vetinari tacitly encourage William, which works within the story but takes the pressure off the conflict and leaves William well short of understanding the underlying politics. There's a lot more that could be said about the tension between the press and the authorities, but I think the Discworld setup isn't suitable for it. This is the sort of book that benefits from twenty-four volumes of backstory and practice. Pratchett's Ankh-Morpork cast ticks along like a well-oiled machine, which frees up space that would otherwise have to be spent on establishing secondary characters. The result is a lot of plot and social analysis shoved into a standard-length Discworld novel, and a story that's hard to put down. The balance between humor and plot is just about perfect, the references and allusions aren't overwhelming, and the supporting characters, both new and old, are excellent. We even get a good Death sequence. This is solid, consistent stuff: Discworld as a mature, well-developed setting with plenty of stories left to tell. Followed by Thief of Time in publication order, and later by Monstrous Regiment in the vaguely-connected industrial revolution sequence. Rating: 8 out of 10

Dirk Eddelbuettel: RcppArmadillo 0.11.4.3.1 on CRAN: Updates

armadillo image Armadillo is a powerful and expressive C++ template library for linear algebra and scientific computing. It aims towards a good balance between speed and ease of use, has a syntax deliberately close to Matlab, and is useful for algorithm development directly in C++, or quick conversion of research code into production environments. RcppArmadillo integrates this library with the R environment and language and is widely used by (currently) 1034 packages other packages on CRAN, downloaded 27.6 million times (per the partial logs from the cloud mirrors of CRAN), and the CSDA paper (preprint / vignette) by Conrad and myself has been cited 509 times according to Google Scholar. This release brings another upstream bugfix interation 11.4.3, released in accordance with the aimed-for monthly release cadence. We had hoped to move away from suppressing deprecation warnings in this release, and had prepared over two dozen patch sets all well as pull requests as documented in issue #391. However, it turns out that we both missed with one or two needed set of changes as well as two other sets of changes triggering deprecation warnings. So we expanded issue #391, and added issue #402 and prepared another eleven pull requests and patches today. With that we can hopefully remove the suppression of these warnings by an expected late of late April. The full set of changes (since the last CRAN release 0.11.4.2.1) follows.

Changes in RcppArmadillo version 0.11.4.3.1 (2023-01-14)
  • The #define ARMA_IGNORE_DEPRECATED_MARKER remains active to suppress the (upstream) deprecation warnings, see #391 and #402 for details.

Changes in RcppArmadillo version 0.11.4.3.0 (2022-12-28) (GitHub Only)
  • Upgraded to Armadillo release 11.4.3 (Ship of Theseus)
    • fix corner case in pinv() when processing symmetric matrices
  • Protect the undefine of NDEBUG behind additional opt-in define

Courtesy of my CRANberries, there is a diffstat report relative to previous release. More detailed information is on the RcppArmadillo page. Questions, comments etc should go to the rcpp-devel mailing list off the R-Forge page. If you like this or other open-source work I do, you can sponsor me at GitHub.

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

Freexian Collaborators: Monthly report about Debian Long Term Support, December 2022 (by Anton Gladky)

Like each month, have a look at the work funded by Freexian s Debian LTS offering.

Debian LTS contributors In December, 17 contributors have been paid to work on Debian LTS, their reports are available:
  • Abhijith PA did 3.0h (out of 0h assigned and 14.0h from previous period), thus carrying over 11.0h to the next month.
  • Anton Gladky did 8.0h (out of 6.0h assigned and 9.0h from previous period), thus carrying over 7.0h to the next month.
  • Ben Hutchings did 24.0h (out of 9.0h assigned and 15.0h from previous period).
  • Chris Lamb did 18.0h (out of 18.0h assigned).
  • Dominik George did 0.0h (out of 10.0h assigned and 14.0h from previous period), thus carrying over 24.0h to the next month.
  • Emilio Pozuelo Monfort did 8.0h in December, 8.0h in November (out of 1.5h assigned and 49.5h from previous period), thus carrying over 43.0h to the next month.
  • Enrico Zini did 0.0h (out of 0h assigned and 8.0h from previous period), thus carrying over 8.0h to the next month.
  • Guilhem Moulin did 17.5h (out of 20.0h assigned), thus carrying over 2.5h to the next month.
  • Helmut Grohne did 15.0h (out of 15.0h assigned, 2.5h were taken from the extra-budget and worked on).
  • Markus Koschany did 40.0h (out of 40.0h assigned).
  • Ola Lundqvist did 10.0h (out of 7.5h assigned and 8.5h from previous period), thus carrying over 6.0h to the next month.
  • Roberto C. S nchez did 24.5h (out of 20.25h assigned and 11.75h from previous period), thus carrying over 7.5h to the next month.
  • Stefano Rivera did 2.5h (out of 20.5h assigned and 14.5h from previous period), thus carrying over 32.5h to the next month.
  • Sylvain Beucler did 20.5h (out of 37.0h assigned and 22.0h from previous period), thus carrying over 38.5h to the next month.
  • Thorsten Alteholz did 10.0h (out of 14.0h assigned), thus carrying over 4.0h to the next month.
  • Tobias Frost did 16.0h (out of 16.0h assigned).
  • Utkarsh Gupta did 51.5h (out of 42.5h assigned and 9.0h from previous period).

Evolution of the situation In December, we have released 47 DLAs, closing 232 CVEs. In the same year, in total we released 394 DLAs, closing 1450 CVEs. We are constantly growing and seeking new contributors. If you are a Debian Developer and want to join the LTS team, please contact us.

Thanks to our sponsors Sponsors that joined recently are in bold.

14 January 2023

Ian Jackson: SGO (and my) VPN and network access tools - in bookworm

Recently, we managed to get secnet and hippotat into Debian. They are on track to go into Debian bookworm. This completes in Debian the set of VPN/networking tools I (and other Greenend) folks have been using for many years. The Sinister Greenend Organisation s suite of network access tools consists mainly of: secnet secnet is our very mature VPN system. Its basic protocol idea is similar to that in Wireguard, but it s much older. Differences from Wireguard include: secnet was originally written by Stephen Early, starting in 1996 or so. I inherited it some years ago and have been maintaining it since. It s mostly written in C. Hippotat Hippotat is best described by copying the intro from the docs:
Hippotat is a system to allow you to use your normal VPN, ssh, and other applications, even in broken network environments that are only ever tested with web stuff . Packets are parcelled up into HTTP POST requests, resembling form submissions (or JavaScript XMLHttpRequest traffic), and the returned packets arrive via the HTTP response bodies.
It doesn t rely on TLS tunnelling so can work even if the local network is trying to intercept TLS. I recently rewrote Hippotat in Rust. userv ipif userv ipif is one of the userv utilities. It allows safe delegation of network routing to unprivileged users. The delegation is of a specific address range, so different ranges can be delegated to different users, and the authorised user cannot interfere with other traffic. This is used in the default configuration of hippotat packages, so that an ordinary user can start up the hippotat client as needed. On chiark userv-ipif is used to delegate networking to users, including administrators of allied VPN realms. So chiark actually runs at least 4 VPN-ish systems in production: secnet, hippotat, Mark Wooding s Tripe, and still a few links managed by the now-superseded udptunnel system. userv userv ipif is a userv service. That is, it is a facility which uses userv to bridge a privilege boundary. userv is perhaps my most under-appreciated program. userv can be used to straightforwardly bridge (local) privilege boundaries on Unix systems. So for example it can: userv services can be defined by the called user, not only by the system administrator. This allows a user to reconfigure or divert a system-provided default implementation, and even allows users to define and implement ad-hoc services of their own. (Although, the system administrator can override user config.) Acknowledgements Thanks for the help I had in this effort. In particular, thanks to Sean Whitton for encouragement, and the ftpmaster review; and to the Debian Rust Team for their help navigating the complexities of handling Rust packages within the Debian Rust Team workflow.

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12 January 2023

Dirk Eddelbuettel: linl 0.0.5 on CRAN: Extended Background Support

A new release of our linl package for writing LaTeX letters with (R)markdown is now on CRAN. linl makes it easy to write letters in markdown, with some extra bells and whistles thanks to some cleverness chiefly by Aaron. This version add extended header and footer placement support thanks to an included copy of wallpaper.sty as added in a nice PR by I aki. As the previous release was well over three years ago, we also enhanced continuous integration in the process. The repository README.md shows some screenshots of input and output files. The NEWS entry follows:

Changes in linl version 0.0.5 (2023-01-11)
  • Several updates to continuous integration and testing
  • Enhanced placment functionality for images in header and footer via wallpaper.sty and new x and y offset variable (I aki Ucar in #30)

Courtesy of CRANberries, there is a comparison to the previous release. More information is on the linl page. For questions or comments use the issue tracker off the GitHub repo. If you like this or other open-source work I do, you can now sponsor me at GitHub.

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

10 January 2023

Dirk Eddelbuettel: RcppTOML 0.2.0: TOML 1.0.0 rewrite with toml++

A few years since the last release in late 2020, the RcppTOML package is now back with a new and shiny CRAN release 0.2.0. It is now based on the wonderful toml++ C++17 library by Mark Gillard and gets us (at long last!) full TOML v1.0.0 compliance for use with R. TOML is a file format that is most suitable for configurations, as it is meant to be edited by humans but read by computers. It emphasizes strong readability for humans while at the same time supporting strong typing as well as immediate and clear error reports. On small typos you get parse errors, rather than silently corrupted garbage. Much preferable to any and all of XML, JSON or YAML though sadly these may be too ubiquitous now. TOML is frequently being used with the projects such as the Hugo static blog compiler, or the Cargo system of Crates (aka packages ) for the Rust language. This package is a rewrite of the internals interfacing the library, and updates the package to using toml++ and C++17. The R interface is unchanged, and a full run of reverse dependencies passed. This involved finding one sole test failure which turned to have been driven by a non-conforming TOML input file which Jianfeng Li kindly fixed at the source making his (extensive) set of tests in package configr pass too. The actual rewrite was mostly done in a one-off repo RcppTomlPlusPlus which can now be considered frozen. The short summary of changes follows.

Changes in version 0.2.0 (2023-01-10)
  • Rewritten in C++17 using toml++ for TOML v1.0.0 compliance
  • Unchanged interface from R, unchanged (and expanded tests)
  • Several small continuous integration upgrades since last release

Courtesy of my CRANberries, there is a diffstat report for this release. More information is on the RcppTOML page page. Please use the GitHub issue tracker for issues and bugreports. If you like this or other open-source work I do, you can sponsor me at GitHub.

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

Matthew Garrett: Integrating Linux with Okta Device Trust

I've written about bearer tokens and how much pain they cause me before, but sadly wishing for a better world doesn't make it happen so I'm making do with what's available. Okta has a feature called Device Trust which allows to you configure access control policies that prevent people obtaining tokens unless they're using a trusted device. This doesn't actually bind the tokens to the hardware in any way, so if a device is compromised or if a user is untrustworthy this doesn't prevent the token ending up on an unmonitored system with no security policies. But it's an incremental improvement, other than the fact that for desktop it's only supported on Windows and MacOS, which really doesn't line up well with my interests.

Obviously there's nothing fundamentally magic about these platforms, so it seemed fairly likely that it would be possible to make this work elsewhere. I spent a while staring at the implementation using Charles Proxy and the Chrome developer tools network tab and had worked out a lot, and then Okta published a paper describing a lot of what I'd just laboriously figured out. But it did also help clear up some points of confusion and clarified some design choices. I'm not going to give a full description of the details (with luck there'll be code shared for that before too long), but here's an outline of how all of this works. Also, to be clear, I'm only going to talk about the desktop support here - mobile is a bunch of related but distinct things that I haven't looked at in detail yet.

Okta's Device Trust (as officially supported) relies on Okta Verify, a local agent. When initially installed, Verify authenticates as the user, obtains a token with a scope that allows it to manage devices, and then registers the user's computer as an additional MFA factor. This involves it generating a JWT that embeds a number of custom claims about the device and its state, including things like the serial number. This JWT is signed with a locally generated (and hardware-backed, using a TPM or Secure Enclave) key, which allows Okta to determine that any future updates from a device claiming the same identity are genuinely from the same device (you could construct an update with a spoofed serial number, but you can't copy the key out of a TPM so you can't sign it appropriately). This is sufficient to get a device registered with Okta, at which point it can be used with Fastpass, Okta's hardware-backed MFA mechanism.

As outlined in the aforementioned deep dive paper, Fastpass is implemented via multiple mechanisms. I'm going to focus on the loopback one, since it's the one that has the strongest security properties. In this mode, Verify listens on one of a list of 10 or so ports on localhost. When you hit the Okta signin widget, choosing Fastpass triggers the widget into hitting each of these ports in turn until it finds one that speaks Fastpass and then submits a challenge to it (along with the URL that's making the request). Verify then constructs a response that includes the challenge and signs it with the hardware-backed key, along with information about whether this was done automatically or whether it included forcing the user to prove their presence. Verify then submits this back to Okta, and if that checks out Okta completes the authentication.

Doing this via loopback from the browser has a bunch of nice properties, primarily around the browser providing information about which site triggered the request. This means the Verify agent can make a decision about whether to submit something there (ie, if a fake login widget requests your creds, the agent will ignore it), and also allows the issued token to be cross-checked against the site that requested it (eg, if g1thub.com requests a token that's valid for github.com, that's a red flag). It's not quite at the same level as a hardware WebAuthn token, but it has many of the anti-phishing properties.

But none of this actually validates the device identity! The entire registration process is up to the client, and clients are in a position to lie. Someone could simply reimplement Verify to lie about, say, a device serial number when registering, and there'd be no proof to the contrary. Thankfully there's another level to this to provide stronger assurances. Okta allows you to provide a CA root[1]. When Okta issues a Fastpass challenge to a device the challenge includes a list of the trusted CAs. If a client has a certificate that chains back to that, it can embed an additional JWT in the auth JWT, this one containing the certificate and signed with the certificate's private key. This binds the CA-issued identity to the Fastpass validation, and causes the device to start appearing as "Managed" in the Okta device management UI. At that point you can configure policy to restrict various apps to managed devices, ensuring that users are only able to get tokens if they're using a device you've previously issued a certificate to.

I've managed to get Linux tooling working with this, though there's still a few drawbacks. The main issue is that the API only allows you to register devices that declare themselves as Windows or MacOS, followed by the login system sniffing browser user agent and only offering Fastpass if you're on one of the officially supported platforms. This can be worked around with an extension that spoofs user agent specifically on the login page, but that's still going to result in devices being logged as a non-Linux OS which makes interpreting the logs more difficult. There's also no ability to choose which bits of device state you log: there's a couple of existing integrations, and otherwise a fixed set of parameters that are reported. It'd be lovely to be able to log arbitrary material and make policy decisions based on that.

This also doesn't help with ChromeOS. There's no real way to automatically launch something that's bound to localhost (you could probably make this work using Crostini but there's no way to launch a Crostini app at login), and access to hardware-backed keys is kind of a complicated topic in ChromeOS for privacy reasons. I haven't tried this yet, but I think using an enterprise force-installed extension and the chrome.enterprise.platformKeys API to obtain a device identity cert and then intercepting requests to the appropriate port range on localhost ought to be enough to do that? But I've literally never written any Javascript so I don't know. Okta supports falling back from the loopback protocol to calling a custom URI scheme, but once you allow that you're also losing a bunch of the phishing protection, so I'd prefer not to take that approach.

Like I said, none of this prevents exfiltration of bearer tokens once they've been issued, and there's still a lot of ecosystem work to do there. But ensuring that tokens can't be issued to unmanaged machines in the first place is still a step forwards, and with luck we'll be able to make use of this on Linux systems without relying on proprietary client-side tooling.

(Time taken to code this implementation: about two days, and under 1000 lines of new code. Time taken to figure out what the fuck to write: rather a lot longer)

[1] There's also support for having Okta issue certificates, but then you're kind of back to the "How do I know this is my device" situation

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