Search Results: "xam"

22 August 2022

Simon Josefsson: Static network config with Debian Cloud images

I self-host some services on virtual machines (VMs), and I m currently using Debian 11.x as the host machine relying on the libvirt infrastructure to manage QEMU/KVM machines. While everything has worked fine for years (including on Debian 10.x), there has always been one issue causing a one-minute delay every time I install a new VM: the default images run a DHCP client that never succeeds in my environment. I never found out a way to disable DHCP in the image, and none of the documented ways through cloud-init that I have tried worked. A couple of days ago, after reading the AlmaLinux wiki I found a solution that works with Debian. The following commands creates a Debian VM with static network configuration without the annoying one-minute DHCP delay. The three essential cloud-init keywords are the NoCloud meta-data parameters dsmode:local, static network-interfaces setting combined with the user-data bootcmd keyword. I m using a Raptor CS Talos II ppc64el machine, so replace the image link with a genericcloud amd64 image if you are using x86.
wget https://cloud.debian.org/images/cloud/bullseye/latest/debian-11-generic-ppc64el.qcow2
cp debian-11-generic-ppc64el.qcow2 foo.qcow2
cat>meta-data
dsmode: local
network-interfaces:  
 iface enp0s1 inet static
 address 192.168.98.14/24
 gateway 192.168.98.12
^D
cat>user-data
#cloud-config
fqdn: foo.mydomain
manage_etc_hosts: true
disable_root: false
ssh_pwauth: false
ssh_authorized_keys:
- ssh-ed25519 AAAA...
timezone: Europe/Stockholm
bootcmd:
- rm -f /run/network/interfaces.d/enp0s1
- ifup enp0s1
^D
virt-install --name foo --import --os-variant debian10 --disk foo.qcow2 --cloud-init meta-data=meta-data,user-data=user-data
Unfortunately virt-install from Debian 11 does not support the cloud-init network-config parameter, so if you want to use a version 2 network configuration with cloud-init (to specify IPv6 addresses, for example) you need to replace the final virt-install command with the following.
cat>network_config_static.cfg
version: 2
 ethernets:
  enp0s1:
   dhcp4: false
   addresses: [ 192.168.98.14/24, fc00::14/7 ]
   gateway4: 192.168.98.12
   gateway6: fc00::12
   nameservers:
    addresses: [ 192.168.98.12, fc00::12 ]
^D
cloud-localds -v -m local --network-config=network_config_static.cfg seed.iso user-data
virt-install --name foo --import --os-variant debian10 --disk foo.qcow2 --disk seed.iso,readonly=on --noreboot
virsh start foo
virsh detach-disk foo vdb --config
virsh console foo
There are still some warnings like the following, but it does not seem to cause any problem: [FAILED] Failed to start Initial cloud-init job (pre-networking). Finally, if you do not want the cloud-init tools installed in your VMs, I found the following set of additional user-data commands helpful. Cloud-init will not be enabled on first boot and a cron job will be added that purges some unwanted packages.
runcmd:
- touch /etc/cloud/cloud-init.disabled
- apt-get update && apt-get dist-upgrade -uy && apt-get autoremove --yes --purge && printf '#!/bin/sh\n  rm /etc/cloud/cloud-init.disabled /etc/cloud/cloud.cfg.d/01_debian_cloud.cfg && apt-get purge --yes cloud-init cloud-guest-utils cloud-initramfs-growroot genisoimage isc-dhcp-client && apt-get autoremove --yes --purge && rm -f /etc/cron.hourly/cloud-cleanup && shutdown --reboot +1;   2>&1   logger -t cloud-cleanup\n' > /etc/cron.hourly/cloud-cleanup && chmod +x /etc/cron.hourly/cloud-cleanup && reboot &
The production script I m using is a bit more complicated, but can be downloaded as vello-vm. Happy hacking!

16 August 2022

Bits from Debian: Debian turns 29!

Alt Happy Birthday Debian by Juliette Taka - click to enlarge Today is Debian's 29th anniversary. We recently wrote about some ideas to celebrate the DebianDay, and several events have been planned in more than 14 locations. You can join the party or organise something yourselves too! Today is also an opportunity for you to start or resume your contributions to Debian. For example, you can have a look at our list of Debian Teams, install the how-can-i-help package and see if there is a bug in any of the software that you use that you can help to fix, start designing your artwork candidate for the next release, contribute small tips on how to install Debian on your machines to our wiki pages https://wiki.debian.org/InstallingDebianOn/, or put a Debian live image in an USB memory and give it to some person near you, who still didn't discover Debian. Our favorite operating system is the result of all the work we do together. Thanks to everybody who has contributed in these 29 years, and happy birthday Debian!

15 August 2022

John Goerzen: The Joy of Easy Personal Radio: FRS, GMRS, and Motorola DLR/DTR

Most of us carry cell phones with us almost everywhere we go. So much so that we often forget not just the usefulness, but even the joy, of having our own radios. For instance: From my own experience, as a person and a family that enjoys visiting wilderness areas, having radio communication is great. I have also heard from others that they re also very useful on cruise ships (I ve never been on one so I can t attest to that). There is also a sheer satisfaction in not needing anybody else s infrastructure, not paying any sort of monthly fee, and setting up the radios ourselves.

How these services fit in This article is primarily about handheld radios that can be used by anybody. I laid out some of their advantages above. Before continuing, I should point out some of the other services you may consider:
  • Cell phones, obviously. Due to the impressive infrastructure you pay for each month (many towers in high locations), in areas of cell coverage, you have this ability to connect to so many other phones around the world. With radios like discussed here, your range will likely a few miles.
  • Amateur Radio has often been a decade or more ahead of what you see in these easy personal radio devices. You can unquestionably get amateur radio devices with many more features and better performance. However, generally speaking, each person that transmits on an amateur radio band must be licensed. Getting an amateur radio license isn t difficult, but it does involve passing a test and some time studying for the exam. So it isn t something you can count on random friends or family members being able to do. That said, I have resources on Getting Started With Amateur Radio and it s not as hard as you might think! There are also a lot of reasons to use amateur radio if you want to go down that path.
  • Satellite messengers such as the Garmin Inreach or Zoleo can send SMS-like messages across anywhere in the globe with a clear view of the sky. They also often have SOS features. While these are useful safety equipment, it can take many minutes for a message to be sent and received it s not like an interactive SMS conversation and there are places where local radios will have better signal. Notably, satellite messengers are almost useless indoors and can have trouble in areas without a clear view of the sky, such as dense forests, valleys, etc.
  • My earlier Roundup of secure messengers with off-the-grid capabilities (distributed/mesh messengers) highlighted a number of other options as well, for text-only communication. For instance:
    • For very short-range service, Briar can form a mesh over Bluetooth from cell phones or over Tor, if Internet access is available.
    • Dedicated short message services Mesh Networks like Meshtastic or Beartooth have no voice capability, but share GPS locations and short text messages over their own local mesh. Generally they need to pair to a cell phone (even if that phone has no cell service) for most functionality.
  • Yggdrasil can do something similar over ad-hoc Wifi, but it is a lower-level protocol and you d need some sort of messaging to run atop it.
This article is primarily about the USA, though these concepts, if not the specific implementation, apply many other areas as well.

The landscape of easy personal radios The oldest personal radio service in the US is Citizens Band (CB). Because it uses a lower frequency band than others, handheld radios are larger, heavier, and less efficient. It is mostly used in vehicles or other installations where size isn t an issue. The FRS/GMRS services mostly share a set of frequencies. The Family Radio Service is unlicensed (you don t have to get a license to use it) and radios are plentiful and cheap. When you get a blister pack or little radios for maybe $50 for a pair or less, they re probably FRS. FRS was expanded by the FCC in 2017, and now most FRS channels can run up to 2 watts of power (with channels 8-14 still limited to 0.5W). FRS radios are pretty much always handheld. GMRS runs on mostly the same frequencies as FRS. GMRS lets you run up to 5W on some channels, up to 50W on others, and operate repeaters. GMRS also permits limited occasional digital data bursts; three manufacturers currently use this to exchange GPS data or text messages. To use GMRS, you must purchase a GMRS license; it costs $35 for a person and their immediate family and is good for 10 years. No exam is required. GMRS radios can transmit on FRS frequencies using the GMRS authorization. The extra power of GMRS gets you extra distance. While only the best handheld GMRS radios can put out 5W of power, some mobile (car) or home radios can put out the full 50W, and use more capable exterior antennas too. There is also the MURS band, which offers very few channels and also very few devices. It is not in wide use, probably for good reason. Finally, some radios use some other unlicensed bands. The Motorola DTR and DLR series I will talk about operate in the 900MHz ISM band. Regulations there limit them to a maximum power of 1W, but as you will see, due to some other optimizations, their range is often quite similar to a 5W GMRS handheld. All of these radios share something in common: your radio can either transmit, or receive, but not both simultaneously. They all have a PTT (push-to-talk) button that you push and hold while you are transmitting, and at all other times, they act as receivers. You ll learn that doubling is a thing where 2 or more people attempt to transmit at the same time. To listeners, the result is often garbled. To the transmitters, they may not even be aware they did it since, after all, they were transmitting. Usually it will be clear pretty quickly as people don t get responses or responses say it was garbled. Only the digital Motorola DLR/DTR series detects and prevents this situation.

FRS and GMRS radios As mentioned, the FRS/GMRS radios are generally the most popular, and quite inexpensive. Those that can emit 2W will have pretty decent range; 5W even better (assuming a decent antenna), though the 5W ones will require a GMRS license. For the most part, there isn t much that differentiates one FRS radio from another, or (with a few more exceptions) one GMRS handheld from another. Do not believe the manufacturers claims of 50 mile range or whatever; more on range below. FRS and GMRS radios use FM. GMRS radios are permitted to use a wider bandwidth than FRS radios, but in general, FRS and GMRS users can communicate with each other from any brand of radio to any other brand of radio, assuming they are using basic voice services. Some FRS and GMRS radios can receive the NOAA weather radio. That s nice for wilderness use. Nicer ones can monitor it for alert tones, even when you re tuned to a different channel. The very nicest on this as far as I know, only the Garmin Rino series will receive and process SAME codes to only trigger alerts for your specific location. GMRS (but not FRS) also permits 1-second digital data bursts at periodic intervals. There are now three radio series that take advantage of this: the Garmin Rino, the Motorola T800, and BTech GMRS-PRO. Garmin s radios are among the priciest of GMRS handhelds out there; the top-of-the-line Rino will set you back $650. The cheapest is $350, but does not contain a replaceable battery, which should be an instant rejection of a device like this. So, for $550, you can get the middle-of-the-road Rino. It features a sophisticated GPS system with Garmin trail maps and such, plus a 5W GMRS radio with GPS data sharing and a very limited (13-character) text messaging system. It does have a Bluetooth link to a cell phone, which can provide a link to trail maps and the like, and limited functionality for the radio. The Rino is also large and heavy (due to its large map-capable screen). Many consider it to be somewhat dated technology; for instance, other ways to have offline maps now exist (such as my Garmin Fenix 6 Pro, which has those maps on a watch!). It is bulky enough to likely be left at home in many situations. The Motorola T800 doesn t have much to talk about compared to the other two. Both of those platforms are a number of years old. The newest entrant in this space, from budget radio maker Baofeng, is the BTech GMRS-PRO, which came out just a couple of weeks ago. Its screen, though lacking built-in maps, does still have a GPS digital link similar to Garmin s, and can show you a heading and distance to other GMRS-PRO users. It too is a 5W unit, and has a ton of advanced features that are rare in GMRS: ability to pair a Bluetooth headset to it directly (though the Garmin Rino supports Bluetooth, it doesn t support this), ability to use the phone app as a speaker/mic for the radio, longer text messages than the Garmin Rino, etc. The GMRS-PRO sold out within a few days of its announcement, and I am presently waiting for mine to arrive to review. At $140 and with a more modern radio implementation, for people that don t need the trail maps and the like, it makes a compelling alternative to Garmin for outdoor use. Garmin documents when GPS beacons are sent out: generally, when you begin a transmission, or when another radio asks for your position. I couldn t find similar documentation from Motorola or BTech, but I believe FCC regulations mean that the picture would be similar with them. In other words, none of these devices is continuously, automatically, transmitting position updates. However, you can request a position update from another radio. It should be noted that, while voice communication is compatible across FRS/GMRS, data communication is not. Garmin, Motorola, and BTech all have different data protocols that are incompatible with radios from other manufacturers. FRS/GMRS radios often advertise privacy codes. These do nothing to protect your privacy; see more under the privacy section below.

Motorola DLR and DTR series Although they can be used for similar purposes, and I do, these radios are unique from the others in this article in several ways:
  • Their sales and marketing is targeted at businesses rather than consumers
  • They use digital encoding of audio, rather than analog FM or AM
  • They use FHSS (Frequency-Hopping Spread Spectrum) rather than a set frequency
  • They operate on the 900MHz ISM band, rather than a 460MHz UHF band (or a lower band yet for MURS and CB)
  • The DLR series is quite small, smaller than many GMRS radios.
I don t have space to go into a lot of radio theory in this article, but I ll briefly expand on some of this. First, FHSS. A FHSS radio hops from frequency to frequency many times per second, following some preset hopping algorithm that is part of the radio. Although it complicates the radio design, it has some advantages; it tends to allow more users to share a band, and if one particular frequency has a conflict with something else, it will be for a brief fraction of a second and may not even be noticeable. Digital encoding generally increases the quality of the audio, and keeps the quality high even in degraded signal conditions where analog radios would experience static or a quieter voice. However, you also lose that sort of audible feedback that your signal is getting weak. When you get too far away, the digital signal drops off a cliff . Often, either you have a crystal-clear signal or you have no signal at all. Motorola s radios leverage these features to build a unique radio. Not only can you talk to a group, but you can select a particular person to talk to with a private conversation, and so forth. DTR radios can send text messages to each other (but only preset canned ones, not arbitrary ones). Channels are more like configurations; they can include various arbitrary groupings of radios. Deconfliction with other users is established via hopsets rather than frequencies; that is, the algorithm that it uses to hop from frequency to frequency. There is a 4-digit PIN in the DLR radios, and newer DTR radios, that makes privacy very easy to set up and maintain. As far as I am aware, no scanner can monitor DLR/DTR signals. Though they technically aren t encrypted, cracking a DLR/DTR conversation would require cracking Motorola s firmware, and the chances of this happening in your geographical proximity seem vanishingly small. I will write more below on comparing the range of these to GMRS radios, but in a nutshell, it compares well, despite the fact that the 900MHz band restrictions allow Motorola only 1W of power output with these radios. There are three current lines of Motorola DLR/DTR radios:
  • The Motorola DLR1020 and DLR1060 radios. These have no screen; the 1020 has two channels (configurations) while the 1060 supports 6. They are small and compact and great pocketable just work radios.
  • The Motorola DTR600 and DTR700 radios. These are larger, with a larger antenna (that should theoretically provide greater range) and have a small color screen. They support more channels and more features (eg, short messages, etc).
  • The Motorola Curve (aka DLR110). Compared to the DLR1060, it adds limited WiFi capabilities that are primarily useful in certain business environments. See this thread for more. These features are unlikely to be useful in the environments we re talking about here.
These radios are fairly expensive new, but DLRs can be readily found at around $60 on eBay. (DTRs for about $250) They are quite rugged. Be aware when purchasing that some radios sold on eBay may not include a correct battery and charger. (Not necessarily a problem; Motorola batteries are easy to find online, and as with any used battery, the life of a used one may not be great.) For more advanced configuration, the Motorola CPS cable works with both radios (plugs into the charging cradle) and is used with the programming software to configure them in more detail. The older Motorola DTR650, DTR550, and older radios are compatible with the newer DLR and DTR series, if you program the newer ones carefully. The older ones don t support PINs and have a less friendly way of providing privacy, but they do work also. However, for most, I think the newer ones will be friendlier; but if you find a deal on the older ones, hey, why not? This thread on the MyGMRS forums has tons of useful information on the DLR/DTR radios. Check it out for a lot more detail. One interesting feature of these radios is that they are aware if there are conflicting users on the channel, and even if anybody is hearing your transmission. If your transmission is not being heard by at least one radio, you will get an audible (and visual, on the DTR) indication that your transmission failed. One thing that pleasantly surprised me is just how tiny the Motorola DLR is. The whole thing with antenna is like a small candy bar, and thinner. My phone is slightly taller, much wider, and only a little thinner than the Motorola DLR. Seriously, it s more pocketable than most smartphones. The DTR is of a size more commonly associated with radios, though still on the smaller side. Some of the most low-power FRS radios might get down to that size, but to get equivolent range, you need a 5W GMRS unit, which will be much bulkier. Being targeted at business users, the DLR/DTR don t include NOAA weather radio or GPS.

Power These radios tend to be powered by:
  • NiMH rechargable battery packs
  • AA/AAA batteries
  • Lithium Ion batteries
Most of the cheap FRS/GMRS radios have a NiMH rechargable battery pack and a terrible charge controller that will tend to overcharge, and thus prematurely destroy, the NiMH packs. This has long ago happened in my GMRS radios, and now I use Eneloop NiMH AAs in them (charged separately by a proper charger). The BTech, Garmin, and Motorola DLR/DTR radios all use Li-Ion batteries. These have the advantage of being more efficient batteries, though you can t necessarily just swap in AAs in a pinch. Pay attention to your charging options; if you are backpacking, for instance, you may want something that can charge from solar-powered USB or battery banks. The Motorola DLR/DTR radios need to sit in a charging cradle, but the cradle is powered by a Micro USB cable. The BTech GMRS-PRO is charged via USB-C. I don t know about the Garmin Rino or others. Garmin offers an optional AA battery pack for the Rino. BTech doesn t (yet) for the GMRS-PRO, but they do for some other models, and have stated accessories for the GMRS-PRO are coming. I don t have information about the T800. This is not an option for the DLR/DTR.

Meshtastic I ll briefly mention Meshtastic. It uses a low-power LoRa system. It can t handle voice transmissions; only data. On its own, it can transmit and receive automatic GPS updates from other Meshtastic devices, which you can view on its small screen. It forms a mesh, so each node can relay messages for others. It is also the only unit in this roundup that uses true encryption, and its battery lasts about a week more than the a solid day you can expect out of the best of the others here. When paired with a cell phone, Meshtastic can also send and receive short text messages. Meshtastic uses much less power than even the cheapest of the FRS radios discussed here. It can still achieve respectable range because it uses LoRa, which can trade bandwidth for power or range. It can take it a second or two to transmit a 50-character text message. Still, the GMRS or Motorola radios discussed here will have more than double the point-to-point range of a Meshtastic device. And, if you intend to take advantage of the text messaging features, keep in mind that you must now take two electronic devices with you and maintain a charge for them both.

Privacy The privacy picture on these is interesting.

Cell phone privacy Cell phones are difficult for individuals to eavesdrop, but a sophisticated adversary probably could: or an unsophisticated adversary with any manner of malware. Privacy on modern smartphones is a huge area of trouble, and it is safe to say that data brokers and many apps probably know at least your location and contact list, if not also the content of your messages. Though end-to-end encrypted apps such as Signal can certainly help. See Tools for Communicating Offline and in Difficult Circumstances for more details.

GMRS privacy GMRS radios are unencrypted and public. Anyone in range with another GMRS radio, or a scanner, can listen to your conversations even if you have a privacy code set. The privacy code does not actually protect your privacy; rather, it keeps your radio from playing conversations from others using the same channel, for your convenience. However, note the in range limitation. An eavesdropper would generally need to be within a few miles of you.

Motorola DLR/DTR privacy As touched on above, while these also aren t encrypted, as far as I am aware, no tools exist to eavesdrop on DLR/DTR conversations. Change the PIN away from the default 0000, ideally to something that doesn t end in 0 (to pick a different hopset) and you have pretty decent privacy right there. Decent doesn t mean perfect; it is certainly possible that sophisticated adversaries or state agencies could decode DLR/DTR traffic, since it is unencrypted. As a practical matter, though, the lack of consumer equipment that can decode this makes it be, as I say, pretty decent .

Meshtastic Meshtastic uses strong AES encryption. But as messaging features require a paired phone, the privacy implications of a phone also apply here.

Range I tested my best 5W GMRS radios, as well as a Motorola DTR600 talking to a DLR1060. (I also tried two DLR1060s talking to each other; there was no change in rnage.) I took a radio with me in the car, and had another sitting on my table indoors. Those of you familiar with radios will probably recognize that being in a car and being indoors both attenuate (reduce the strength of) the signal significantly. I drove around in a part of Kansas with gentle rolling hills. Both the GMRS and the DLR/DTR had a range of about 2-3 miles. There were times when each was able to pull out a signal when the other was not. The DLR/DTR series was significantly better while the vehicle was in motion. In weaker signal conditions, the GMRS radios were susceptible to significant picket fencing (static caused by variation in the signal strength when passing things like trees), to the point of being inaudible or losing the signal entirely. The DLR/DTR remained perfectly clear there. I was able to find some spots where, while parked, the GMRS radios had a weak but audible signal but the DLR/DTR had none. However, in all those cases, the distance to GMRS dropping out as well was small. Basically, no radios penetrate the ground, and the valleys were a problem for them all. Differences may play out in other ways in other environments as well: for instance, dense urban environments, heavy woods, indoor buildings, etc. GMRS radios can be used with repeaters, or have a rooftop antenna mounted on a car, both of which could significantly extend range and both of which are rare. The DLR/DTR series are said to be exceptionally good at indoor environments; Motorola rates them for penetrating 20 floors, for instance. Reports on MyGMRS forums state that they are able to cover an entire cruise ship, while the metal and concrete in them poses a big problem for GMRS radios. Different outdoor landscapes may favor one or the other also. Some of the cheapest FRS radios max out at about 0.5W or even less. This is probably only a little better than yelling distance in many cases. A lot of manufacturers obscure transmit power and use outlandish claims of range instead; don t believe those. Find the power output. A 2W FRS transmitter will be more credible range-wise, and the 5W GMRS transmitter as I tested better yet. Note that even GMRS radios are restricted to 0.5W on channels 8-14. The Motorola DLR/DTR radio gets about the same range with 1W as a GMRS radio does with 5W. The lower power output allows the DLR to be much smaller and lighter than a 5W GMRS radio for similar performance.

Overall conclusions Of course, what you use may depend on your needs. I d generally say:
  • For basic use, the high quality, good range, reasonable used price, and very small size of the Motorola DLR would make it a good all-arounder. Give one to each person (or kid) for use at the mall or amusement park, take them with you to concerts and festivals, etc.
  • Between vehicles, the Motorola DLR/DTR have a clear range advantage over the GMRS radios for vehicles in motion, though the GPS features of the more advanced GMRS radios may be more useful here.
  • For wilderness hiking and the like, GMRS radios that have GPS, maps, and NOAA weather radio reception may prove compelling and worth the extra bulk. More flexible power options may also be useful.
  • Low-end FRS radios can be found very cheap; around $20-$30 new for the lowest end, though their low power output and questionable charging circuits may limit their utility where it really counts.
  • If you just can t move away from cell phones, try the Zoleo app, which can provide some radio-like features.
  • A satellite communicator is still good backup safety gear for the wilderness.

Postscript: A final plug for amateur radio My 10-year-old Kenwood TH-D71A already had features none of these others have. For instance, its support for APRS and ability to act as a digipeater for APRS means that TH-D71As can form an automatic mesh between them, each one repeating new GPS positions or text messages to the others. Traditional APRS doesn t perform well in weak signal situations; however, more modern digital systems like D-Star and DMR also support APRS over more modern codecs and provide all sorts of other advantages as well (though not FHSS). My conclusions above assume a person is not going to go the amateur radio route for whatever reason. If you can get those in your group to get their license the technician is all you need a whole world of excellent options opens to you.

Appendix: The Trisquare eXRS Prior to 2012, a small company named Trisquare made a FHSS radio they called the eXRS that operated on the 900MHz band like Motorola s DLR/DTR does. Trisquare aimed at consumers and their radios were cheaper than the Motorola DLR/DTR. However, that is where the similarities end. Trisquare had an analog voice transmission, even though it used FHSS. Also, there is a problem that can arise with FHSS systems: synchronization. The receiver must hop frequencies in exactly the same order at exactly the same time as the sender. Motorola has clearly done a lot of engineering around this, and I have never encountered a synchronization problem in my DLR/DTR testing, not even once. eXRS, on the other hand, had frequent synchronization problems, which manifested themselves in weak signal conditions and sometimes with doubling. When it would happen, everyone would have to be quiet for a minute or two to give all the radios a chance to timeout and reset to the start of the hop sequence. In addition, the eXRS hardware wasn t great, and was susceptible to hardware failure. There are some that still view eXRS as a legendary device and hoard them. You can still find them used on eBay. When eXRS came out in 2007, it was indeed nice technology for the day, ahead of its time in some ways. I used and loved the eXRS radios back then; powerful GMRS wasn t all that common. But compared to today s technology, eXRS has inferior range to both GMRS and Motorola DLR/DTR (from my recollection, about a third to half of what I get with today s GMRS and DLR/DTR), is prone to finicky synchronization issues when signals are weak, and isn t made very robustly. I therefore don t recommend the eBay eXRS units. Don t assume that the eXRS weaknesses extend to Motorola DLR/DTR. The DLR/DTR radios are done well and don t suffer from the same problems. Note: This article has a long-term home on my website, where it may be updated from time to time.

14 August 2022

Russ Allbery: Review: Still Not Safe

Review: Still Not Safe, by Robert L. Wears & Kathleen M. Sutcliffe
Publisher: Oxford University Press
Copyright: November 2019
ISBN: 0-19-027128-0
Format: Kindle
Pages: 232
Still Not Safe is an examination of the recent politics and history of patient safety in medicine. Its conclusions are summarized by the opening paragraph of the preface:
The American moral and social philosopher Eric Hoffer reportedly said that every great cause begins as a movement, becomes a business, and eventually degenerates into a racket. The reform movement to make healthcare safer is clearly a great cause, but patient safety efforts are increasingly following Hoffer's path.
Robert Wears was Professor of Emergency Medicine at the University of Florida specializing in patient safety. Kathleen Sutcliffe is Professor of Medicine and Business at Johns Hopkins. This book is based on research funded by a grant from the Robert Wood Johnson Foundation, for which both Wears and Sutcliffe were primary investigators. (Wears died in 2017, but the acknowledgments imply that at least early drafts of the book existed by that point and it was indeed co-written.) The anchor of the story of patient safety in Still Not Safe is the 1999 report from the Institute of Medicine entitled To Err is Human, to which the authors attribute an explosion of public scrutiny of medical safety. The headline conclusion of that report, which led nightly news programs after its release, was that 44,000 to 120,000 people died each year in the United States due to medical error. This report prompted government legislation, funding for new safety initiatives, a flurry of follow-on reports, and significant public awareness of medical harm. What it did not produce, in the authors' view, is significant improvements in patient safety. The central topic of this book is an analysis of why patient safety efforts have had so little measurable effect. The authors attribute this to three primary causes: an unwillingness to involve safety experts from outside medicine or absorb safety lessons from other disciplines, an obsession with human error that led to profound misunderstandings of the nature of safety, and the misuse of safety concerns as a means to centralize control of medical practice in the hands of physician-administrators. (The term used by the authors is "managerial, scientific-bureaucratic medicine," which is technically accurate but rather awkward.) Biggest complaint first: This book desperately needed examples, case studies, or something to make these ideas concrete. There are essentially none in 230 pages apart from passing mentions of famous cases of medical error that added to public pressure, and a tantalizing but maddeningly nonspecific discussion of the atypically successful effort to radically improve the safety of anesthesia. Apparently anesthesiologists involved safety experts from outside medicine, avoided a focus on human error, turned safety into an engineering problem, and made concrete improvements that had a hugely positive impact on the number of adverse events for patients. Sounds fascinating! Alas, I'm just as much in the dark about what those improvements were as I was when I started reading this book. Apart from a vague mention of some unspecified improvements to anesthesia machines, there are no concrete descriptions whatsoever. I understand that the authors were probably leery of giving too many specific examples of successful safety initiatives since one of their core points is that safety is a mindset and philosophy rather than a replicable set of actions, and copying the actions of another field without understanding their underlying motivations or context within a larger system is doomed to failure. But you have to give the reader something, or the book starts feeling like a flurry of abstract assertions. Much is made here of the drawbacks of a focus on human error, and the superiority of the safety analysis done in other fields that have moved beyond error-centric analysis (and in some cases have largely discarded the word "error" as inherently unhelpful and ambiguous). That leads naturally to showing an analysis of an adverse incident through an error lens and then through a more nuanced safety lens, making the differences concrete for the reader. It was maddening to me that the authors never did this. This book was recommended to me as part of a discussion about safety and reliability in tech and the need to learn from safety practices in other fields. In that context, I didn't find it useful, although surprisingly that's because the thinking in medicine (at least as presented by these authors) seems behind the current thinking in distributed systems. The idea that human error is not a useful model for approaching reliability is standard in large tech companies, nearly all of which use blameless postmortems for exactly that reason. Tech, similar to medicine, does have a tendency to be insular and not look outside the field for good ideas, but the approach to large-scale reliability in tech seems to have avoided the other traps discussed here. (Security is another matter, but security is also adversarial, which creates different problems that I suspect require different tools.) What I did find fascinating in this book, although not directly applicable to my own work, is the way in which a focus on human error becomes a justification for bureaucratic control and therefore a concentration of power in a managerial layer. If the assumption is that medical harm is primarily caused by humans making avoidable mistakes, and therefore the solution is to prevent humans from making mistakes through better training, discipline, or process, this creates organizations that are divided into those who make the rules and those who follow the rules. The long-term result is a practice of medicine in which a small number of experts decide the correct treatment for a given problem, and then all other practitioners are expected to precisely follow that treatment plan to avoid "errors." (The best distributed systems approaches may avoid this problem, but this failure mode seems nearly universal in technical support organizations.) I was startled by how accurate that portrayal of medicine felt. My assumption prior to reading this book was that the modern experience of medicine as an assembly line with patients as widgets was caused by the pressure for higher "productivity" and thus shorter visit times, combined with (in the US) the distorting effects of our broken medical insurance system. After reading this book, I've added a misguided way of thinking about medical error and risk avoidance to that analysis. One of the authors' points (which, as usual, I wish they'd made more concrete with a case study) is that the same thought process that lets a doctor make a correct diagnosis and find a working treatment is the thought process that may lead to an incorrect diagnosis or treatment. There is not a separable state of "mental error" that can be eliminated. Decision-making processes are more complicated and more integrated than that. If you try to prevent "errors" by eliminating flexibility, you also eliminate vital tools for successfully treating patients. The authors are careful to point out that the prior state of medicine in which each doctor was a force to themselves and there was no role for patient safety as a discipline was also bad for safety. Reverting to the state of medicine before the advent of the scientific-bureaucratic error-avoiding culture is also not a solution. But, rather at odds with other popular books about medicine, the authors are highly critical of safety changes focused on human error prevention, such as mandatory checklists. In their view, this is exactly the sort of attempt to blindly copy the machinery of safety in another field (in this case, air travel) without understanding the underlying purpose and system of which it's a part. I am not qualified to judge the sharp dispute over whether there is solid clinical evidence that checklists are helpful (these authors claim there is not; I know other books make different claims, and I suspect it may depend heavily on how the checklist is used). But I found the authors' argument that one has to design systems holistically for safety, not try to patch in safety later by turning certain tasks into rote processes and humans into machines, to be persuasive. I'm not willing to recommend this book given how devoid it is of concrete examples. I was able to fill in some of that because of prior experience with the literature on site reliability engineering, but a reader who wasn't previously familiar with discussions of safety or reliability may find much of this book too abstract to be comprehensible. But I'm not sorry I read it. I hadn't previously thought about the power dynamics of a focus on error, and I think that will be a valuable observation to keep in mind. Rating: 6 out of 10

10 August 2022

Shirish Agarwal: Mum, Samsung Galaxy M-52

Mum I dunno from where to start. While I m not supposed to announce it, mum left this earth a month ago (thirteen days when I started to write this blog post) ago. I am still in part denial, part shock, and morose. Of all the seasons in a year, the rainy season used to be my favorite, now would I ever be able to look and feel other than the emptiness that this season has given me? In some senses, it is and was very ironic, when she became ill about last year, I had promised myself I would be by her side for 5-6 years, not go anywhere either Hillhacks or Debconf or any meetup and I was ok with that. Now that she s no more I have no clue why am I living. What is the purpose, the utility? When she was alive, the utility was understandable. We had an unspoken agreement, I would like after her, and she was supposed to look after me. A part of me self-blames as I am sure, I have done thousands of things wrong otherwise the deal was that she was going to be for another decade. But now that she has left not even halfway, I dunno what to do. I don t have someone to fight with anymore  It s mostly a robotic existence atm. I try to distract myself via movies, web series, the web, books, etc. whatever can take my mind off. From the day she died to date, I have a lower back pain which acts as a reminder. It s been a month, I eat, drink, and am surviving but still feel empty. I do things suggested by extended family but within there is no feeling, just emptiness :(. I have no clue if things will get better and even if I do want the change. I clearly have no idea, so let me share a little about what I know.

Samsung Galaxy M-52G Just a couple of days before she died, part of our extended family had come and she chose that opportunity to gift me Samsung Galaxy M-52G even though my birthday was 3 months away. Ironically, after I purchased it, the next day, one of the resellers of the phone cut the price from INR 28k to 20k. If a day more, I could have saved another 8k/- but what s done is done  To my mind, the phone is middling yet a solid phone. I had the phone drop accidentally at times but not a single scratch or anything like that. One can look at the specs in greater detail on fccd.io. Before the recent price drop, as I shared it was a mid-range phone so am gonna review it on that basis itself. One of the first things I did is to buy a plastic cover as well as a cover shield even though the original one is meant to work for a year or more. This was simply for added protection and it has served me to date. Even with the additional weight, I can easily use it with one hand. It only becomes problematic when using chatting apps. such as Whatsapp, Telegram, Quicksy and a few others where it comes with Samsung keyboard with the divided/split keyboard. The A.I. for guessing words and sentences are spot-on when you are doing it in English but if you try a mixture of Hinglish (Hindi and English) that becomes a bit of a nightmare. Tryng to each A.I; new words is something of a task. I wish there was an interface in which I could train the A.I. so it could be served for Hinglish words also. I do think it does, but it s too rudimentary as it is to be any useful at least where it is now.

WiFi Direct While my previous phone did use wifi direct but it that ancient android version wasn t wedded to Wifi Direct as this one is. You have essentially two ways to connect to any system outside. One is through Wi-Fi Direct and the more expensive way is through mobile data. One of the strange things I found quite a number of times, that Wifi would lose it pairings. Before we get into it, Wikipedia has a good explanation of what Wifi direct is all about. Apparently, either my phone or my modem loses the pairing, which of the two is the culprit, I really don t know. There are two apps from the Play Store that do help in figuring out what the issue is (although it is limited in what it gives out in info. but still good.) The first one is Wifi Signal Meter and the other one is WifiAnalyzer (open-source). I have found that pairing done through Wifi Signal Meter works better than through Google s own implementation which feels lacking. The whole universe of Android seems to be built on apps and games and many of these can be bought for money, but many of these can also be played using a combination of micro-transactions and ads. For many a game, you cannot play for more than 5 minutes before you either see an ad or wait for something like 2-3 hrs. before you attempt again. Hogwarts Mystery, for e.g., is an example of that. Another one would be Explore Lands . While Hogwarts Mystery is more towards the lore created by J.K.Rowling and you can really get into the thick of things if you know the lore, Explore lands is more into Exploration of areas. In both the games, you are basically looking to gain energy over a period of time, which requires either money or viewing ads or a combination of both Sadly most ads and even Google don t seem to have caught up that I m deaf so most ads do not have subtitles, so more often than not they are useless to me. I have found also that many games share screenshots or videos that have nothing to do with how the game is. So there is quite a bit of misleading going on. I did read that Android had been having issues with connecting with developers after their app. is in the Play Store. Most apps. ask and require a whole lot of permissions that aren t needed by that app.

F-Droid Think Pirate Praveen had introduced me to F-Droid and a whole lot of things have happened in F-Droid, lot more apps. games etc. the look of F-Droid has been pulled back. In fact, I found Neo Store to be a better skin to see F-Droid. I have yet to explore more of F-Droid before sharing any recommendations and spending some time on it. I do find that many of foss apps. do need to work on how we communicate with our users. For e.g. one app. that Praveen had shared with me recently was Quicksy. And while it is better, it uses a double negative while asking permission whether it should or not to use more of the phone s resources. It is an example of that sort of language that we need to be aware of and be better. I know this post is more on the mobile rather than the desktop but that is where I m living currently.

8 August 2022

Ian Jackson: dkim-rotate - rotation and revocation of DKIM signing keys

Background Internet email is becoming more reliant on DKIM, a scheme for having mail servers cryptographically sign emails. The Big Email providers have started silently spambinning messages that lack either DKIM signatures, or SPF. DKIM is arguably less broken than SPF, so I wanted to deploy it. But it has a problem: if done in a naive way, it makes all your emails non-repudiable, forever. This is not really a desirable property - at least, not desirable for you, although it can be nice for someone who (for example) gets hold of leaked messages obtained by hacking mailboxes. This problem was described at some length in Matthew Green s article Ok Google: please publish your DKIM secret keys. Following links from that article does get you to a short script to achieve key rotation but it had a number of problems, and wasn t useable in my context. dkim-rotate So I have written my own software for rotating and revoking DKIM keys: dkim-rotate. I think it is a good solution to this problem, and it ought to be deployable in many contexts (and readily adaptable to those it doesn t already support). Here s the feature list taken from the README: Complications It seems like it should be a simple problem. Keep N keys, and every day (or whatever), generate and start using a new key, and deliberately leak the oldest private key. But, things are more complicated than that. Considerably more complicated, as it turns out. I didn t want the DKIM key rotation software to have to edit the actual DNS zones for each relevant mail domain. That would tightly entangle the mail server administration with the DNS administration, and there are many contexts (including many of mine) where these roles are separated. The solution is to use DNS aliases (CNAME). But, now we need a fixed, relatively small, set of CNAME records for each mail domain. That means a fixed, relatively small set of key identifiers ( selectors in DKIM terminology), which must be used in rotation. We don t want the private keys to be published via the DNS because that makes an ever-growing DNS zone, which isn t great for performance; and, because we want to place barriers in the way of processes which might enumerate the set of keys we use (and the set of keys we have leaked) and keep records of what status each key had when. So we need a separate publication channel - for which a webserver was the obvious answer. We want the private keys to be readily noticeable and findable by someone who is verifying an alleged leaked email dump, but to be hard to enumerate. (One part of the strategy for this is to leave a note about it, with the prospective private key url, in the email headers.) The key rotation operations are more complicated than first appears, too. The short summary, above, neglects to consider the fact that DNS updates have a nonzero propagation time: if you change the DNS, not everyone on the Internet will experience the change immediately. So as well as a timeout for how long it might take an email to be delivered (ie, how long the DKIM signature remains valid), there is also a timeout for how long to wait after updating the DNS, before relying on everyone having got the memo. (This same timeout applies both before starting to sign emails with a new key, and before deliberately compromising a key which has been withdrawn and deadvertised.) Updating the DNS, and the MTA configuration, are fallible operations. So we need to cope with out-of-course situations, where a previous DNS or MTA update failed. In that case, we need to retry the failed update, and not proceed with key rotation. We mustn t start the timer for the key rotation until the update has been implemented. The rotation script will usually be run by cron, but it might be run by hand, and when it is run by hand it ought not to jump the gun and do anything too early (ie, before the relevant timeout has expired). cron jobs don t always run, and don t always run at precisely the right time. (And there s daylight saving time, to consider, too.) So overall, it s not sufficient to drive the system via cron and have it proceed by one unit of rotation on each run. And, hardest of all, I wanted to support post-deployment configuration changes, while continuing to keep the whole the system operational. Otherwise, you have to bake in all the timing parameters right at the beginning and can t change anything ever. So for example, I wanted to be able to change the email and DNS propagation delays, and even the number of selectors to use, without adversely affecting the delivery of already-sent emails, and without having to shut anything down. I think I have solved these problems. The resulting system is one which keeps track of the timing constraints, and the next event which might occur, on a per-key basis. It calculates on each run, which key(s) can be advanced to the next stage of their lifecycle, and performs the appropriate operations. The regular key update schedule is then an emergent property of the config parameters and cron job schedule. (I provide some example config.) Exim Integrating dkim-rotate itself with Exim was fairly easy. The lsearch lookup function can be used to fish information out of a suitable data file maintained by dkim-rotate. But a final awkwardness was getting Exim to make the right DKIM signatures, at the right time. When making a DKIM signature, one must choose a signing authority domain name: who should we claim to be? (This is the SDID in DKIM terms.) A mailserver that handles many different mail domains will be able to make good signatures on behalf of many of them. It seems to me that domain to be the mail domain in the From: header of the email. (The RFC doesn t seem to be clear on what is expected.) Exim doesn t seem to have anything builtin to do that. And, you only want to DKIM-sign emails that are originated locally or from trustworthy sources. You don t want to DKIM-sign messages that you received from the global Internet, and are sending out again (eg because of an email alias or mailing list). In theory if you verify DKIM on all incoming emails, you could avoid being fooled into signing bad emails, but rejecting all non-DKIM-verified email would be a very strong policy decision. Again, Exim doesn t seem to have cooked machinery. The resulting Exim configuration parameters run to 22 lines, and because they re parameters to an existing config item (the smtp transport) they can t even easily be deployed as a drop-in file via Debian s split config Exim configuration scheme. (I don t know if the file written for Exim s use by dkim-rotate would be suitable for other MTAs, but this part of dkim-rotate could easily be extended.) Conclusion I have today released dkim-rotate 0.4, which is the first public release for general use. I have it deployed and working, but it s new so there may well be bugs to work out. If you would like to try it out, you can get it via git from Debian Salsa. (Debian folks can also find it freshly in Debian unstable.)

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6 August 2022

Dirk Eddelbuettel: RcppCCTZ 0.2.11 on CRAN: Updates

A new release 0.2.11 of RcppCCTZ is now on CRAN. RcppCCTZ uses Rcpp to bring CCTZ to R. CCTZ is a C++ library for translating between absolute and civil times using the rules of a time zone. In fact, it is two libraries. One for dealing with civil time: human-readable dates and times, and one for converting between between absolute and civil times via time zones. And while CCTZ is made by Google(rs), it is not an official Google product. The RcppCCTZ page has a few usage examples and details. This package was the first CRAN package to use CCTZ; by now four others packages include its sources too. Not ideal, but beyond our control. This version updates the include headers used in the interface API header thanks to a PR by Jing Lu, updates to upstream changes, and switched r-ci CI to r2u.

Changes in version 0.2.11 (2022-08-06)
  • More specific includes in RcppCCTZ_API.h (Jing Lu in #42 closing #41).
  • Synchronized with upstream CCTZ (Dirk in #43).
  • Switched r-ci to r2u use.

Courtesy of my CRANberries, there is also a diffstat to the previous version. More details are at the RcppCCTZ page; code, issue tickets etc at the GitHub repository. 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.

4 August 2022

Jamie McClelland: Fine tuning Thunderbird's end-to-end encryption

I love that Thunderbird really tackled OpenPGP head on and incorporated it directly into the client. I know it s been a bit rough for some users, but I think it s a good long term investment. And to demonstrate I ll now complain about a minor issue :). I replied to an encrypted message but couldn t send the response using encryption. I got an error message indicating that End-to-end encryption requires resolving certificate issues for and it listed the recipient email address. Screen shot of error message saying: End-to-end encryption requires resolving certificate issues for I spent an enormous amount of time examining the recipient s OpenPGP key. I made sure it was not expired. I made sure it was actually in my Thunderbird key store not just in my OpenPGP keychain. I made sure I had indicated that I trust it enough to use. I re-downloaded it. I eventually gave up and didn t send the email. Then I responded to another encrypted email and it worked. What!?!? I spent more time comparing the recipients before I realized the problem was the sending address, not the recipient address. I have an OpenPGP key that lists several identities. I have a Thunderbird Account that uses the Identities feature to add several from addresses. And, it turns out that in Thunderbird, you need to indicate which OpenPGP key to use for your main account but also for each identity. When you drill down to Manage Identities for your account, you are able to indicate which OpenPGP key you want to use for each identity. Once I indicated that each identity should use my OpenPGP key, the issue was resolved. And here s my Thunderbird bug asking for an error message pointing to the sender address, not the recipient address.

Jamie McClelland: Fine tuning Thunderbird's end-to-end encryption

I love that Thunderbird really tackled OpenPGP head on and incorporated it directly into the client. I know it s been a bit rough for some users, but I think it s a good long term investment. And to demonstrate I ll now complain about a minor issue :). I replied to an encrypted message but couldn t send the response using encryption. I got an error message indicating that End-to-end encryption requires resolving certificate issues for and it listed the recipient email address. “Screen shot of error message saying: End-to-end encryption requires resolving certificate issues for [blacked out email address]” I spent an enormous amount of time examining the recipient s OpenPGP key. I made sure it was not expired. I made sure it was actually in my Thunderbird key store not just in my OpenPGP keychain. I made sure I had indicated that I trust it enough to use. I re-downloaded it. I eventually gave up and didn t send the email. Then I responded to another encrypted email and it worked. What!?!? I spent more time comparing the recipients before I realized the problem was the sending address, not the recipient address. I have an OpenPGP key that lists several identities. I have a Thunderbird Account that uses the Identities feature to add several from addresses. And, it turns out that in Thunderbird, you need to indicate which OpenPGP key to use for your main account but also for each identity. When you drill down to Manage Identities for your account, you are able to indicate which OpenPGP key you want to use for each identity. Once I indicated that each identity should use my OpenPGP key, the issue was resolved. And here s my Thunderbird bug asking for an error message pointing to the sender address, not the recipient address.

Reproducible Builds: Reproducible Builds in July 2022

Welcome to the July 2022 report from the Reproducible Builds project! In our reports we attempt to outline the most relevant things that have been going on in the past month. As a brief introduction, the reproducible builds effort is concerned with ensuring no flaws have been introduced during this compilation process by promising identical results are always generated from a given source, thus allowing multiple third-parties to come to a consensus on whether a build was compromised. As ever, if you are interested in contributing to the project, please visit our Contribute page on our website.

Reproducible Builds summit 2022 Despite several delays, we are pleased to announce that registration is open for our in-person summit this year: November 1st November 3rd
The event will happen in Venice (Italy). We intend to pick a venue reachable via the train station and an international airport. However, the precise venue will depend on the number of attendees. Please see the announcement email for information about how to register.

Is reproducibility practical? Ludovic Court s published an informative blog post this month asking the important question: Is reproducibility practical?:
Our attention was recently caught by a nice slide deck on the methods and tools for reproducible research in the R programming language. Among those, the talk mentions Guix, stating that it is for professional, sensitive applications that require ultimate reproducibility , which is probably a bit overkill for Reproducible Research . While we were flattered to see Guix suggested as good tool for reproducibility, the very notion that there s a kind of reproducibility that is ultimate and, essentially, impractical, is something that left us wondering: What kind of reproducibility do scientists need, if not the ultimate kind? Is reproducibility practical at all, or is it more of a horizon?
The post goes on to outlines the concept of reproducibility, situating examples within the context of the GNU Guix operating system.

diffoscope diffoscope is our in-depth and content-aware diff utility. Not only can it locate and diagnose reproducibility issues, it can provide human-readable diffs from many kinds of binary formats. This month, Chris Lamb prepared and uploaded versions 218, 219 and 220 to Debian, as well as made the following changes:
  • New features:
  • Bug fixes:
    • Fix a regression introduced in version 207 where diffoscope would crash if one directory contained a directory that wasn t in the other. Thanks to Alderico Gallo for the testcase. [ ]
    • Don t traceback if we encounter an invalid Unicode character in Haskell versioning headers. [ ]
  • Output improvements:
  • Codebase improvements:
    • Space out a file a little. [ ]
    • Update various copyright years. [ ]

Mailing list On our mailing list this month:
  • Roland Clobus posted his Eleventh status update about reproducible [Debian] live-build ISO images, noting amongst many other things! that all major desktops build reproducibly with bullseye, bookworm and sid.
  • Santiago Torres-Arias announced a Call for Papers (CfP) for a new SCORED conference, an academic workshop around software supply chain security . As Santiago highlights, this new conference invites reviewers from industry, open source, governement and academia to review the papers [and] I think that this is super important to tackle the supply chain security task .

Upstream patches The Reproducible Builds project attempts to fix as many currently-unreproducible packages as possible. This month, however, we submitted the following patches:

Reprotest reprotest is the Reproducible Builds project s end-user tool to build the same source code twice in widely and deliberate different environments, and checking whether the binaries produced by the builds have any differences. This month, the following changes were made:
  • Holger Levsen:
    • Uploaded version 0.7.21 to Debian unstable as well as mark 0.7.22 development in the repository [ ].
    • Make diffoscope dependency unversioned as the required version is met even in Debian buster. [ ]
    • Revert an accidentally committed hunk. [ ]
  • Mattia Rizzolo:
    • Apply a patch from Nick Rosbrook to not force the tests to run only against Python 3.9. [ ]
    • Run the tests through pybuild in order to run them against all supported Python 3.x versions. [ ]
    • Fix a deprecation warning in the setup.cfg file. [ ]
    • Close a new Debian bug. [ ]

Reproducible builds website A number of changes were made to the Reproducible Builds website and documentation this month, including:
  • Arnout Engelen:
  • Chris Lamb:
    • Correct some grammar. [ ]
  • Holger Levsen:
    • Add talk from FOSDEM 2015 presented by Holger and Lunar. [ ]
    • Show date of presentations if we have them. [ ][ ]
    • Add my presentation from DebConf22 [ ] and from Debian Reunion Hamburg 2022 [ ].
    • Add dhole to the speakers of the DebConf15 talk. [ ]
    • Add raboof s talk Reproducible Builds for Trustworthy Binaries from May Contain Hackers. [ ]
    • Drop some Debian-related suggested ideas which are not really relevant anymore. [ ]
    • Add a link to list of packages with patches ready to be NMUed. [ ]
  • Mattia Rizzolo:
    • Add information about our upcoming event in Venice. [ ][ ][ ][ ]

Testing framework The Reproducible Builds project runs a significant testing framework at tests.reproducible-builds.org, to check packages and other artifacts for reproducibility. This month, Holger Levsen made the following changes:
  • Debian-related changes:
    • Create graphs displaying existing .buildinfo files per each Debian suite/arch. [ ][ ]
    • Fix a typo in the Debian dashboard. [ ][ ]
    • Fix some issues in the pkg-r package set definition. [ ][ ][ ]
    • Improve the builtin-pho HTML output. [ ][ ][ ][ ]
    • Temporarily disable all live builds as our snapshot mirror is offline. [ ]
  • Automated node health checks:
    • Detect dpkg failures. [ ]
    • Detect files with bad UNIX permissions. [ ]
    • Relax a regular expression in order to detect Debian Live image build failures. [ ]
  • Misc changes:
    • Test that FreeBSD virtual machine has been updated to version 13.1. [ ]
    • Add a reminder about powercycling the armhf-architecture mst0X node. [ ]
    • Fix a number of typos. [ ][ ]
    • Update documentation. [ ][ ]
    • Fix Munin monitoring configuration for some nodes. [ ]
    • Fix the static IP address for a node. [ ]
In addition, Vagrant Cascadian updated host keys for the cbxi4pro0 and wbq0 nodes [ ] and, finally, node maintenance was also performed by Mattia Rizzolo [ ] and Holger Levsen [ ][ ][ ].

Contact As ever, if you are interested in contributing to the Reproducible Builds project, please visit our Contribute page on our website. However, you can get in touch with us via:

28 July 2022

Dominique Dumont: How I investigated connection hogs on Kubernetes

Hi My name is Dominhique Dumont, DevOps freelance in Grenoble, France. My goal is to share my experience regarding a production issue that occurred last week where my client complained that the applications was very slow and sometime showed 5xx errors. The production service is hosted on a Kubernetes cluster on Azure and use a MongoDB on ScaleGrid. I reproduced the issue on my side and found that the API calls were randomly failing due to timeouts on server side. The server logs were showing some MongoDB disconnections and reconnections and some time-out on MongoDB connections, but did not give any clue on why some connections to MongoDB server were failing. Since there was not clue in the cluster logs, I looked at ScaleGrid monitoring. There was about 2500 connections on MongoDB: 2022-07-19-scalegrid-connection-leak.png That seemed quite a lot given the low traffic at that time, but not necessarily a problem. Then, I went to the Azure console, and I got the first hint about the origin of the problem: the SNATs were exhausted on some nodes of the clusters. 2022-07-28_no-more-free-snat.png SNATs are involved in connections from the cluster to the outside world, i.e. to our MongoDB server and are quite limited: only 1024 SNAT ports are available per node. This was consistent with the number of used connections on MongoDB. OK, then the number of used connections on MongoDB was a real problem. The next question was: which pods and how many connections ? First I had to filter out the pods that did not use MongoDB. Fortunately, all our pods have labels so I could list all pods using MongoDB:
$ kubectl -n prod get pods -l db=mongo   wc -l
236
Hmm, still quite a lot. Next problem is to check which pod used too many MongoDB connections. Unfortunately, the logs mentioned that a connection to MongoDB was opened, but that did not give a clue on how many were used. Netstat is not installed on the pods, and cannot be installed since the pods are running as root (which is a good idea for security reasons) Then, my Debian Developer experience kicked in and I remembered that /proc file system on Linux gives a lot of information on consumed kernel resources, including resources consumed by each process. The trick is to know the PID of the process using the connections. In our case, Docker files are written in a way so the main process of a pod using NodeJS is 1, so, the command to list the connections of pod is:
$ kubectl -n prod exec redacted-pod-name-69875496f8-8bj4f -- cat /proc/1/net/tcp
  sl  local_address rem_address   st tx_queue rx_queue tr tm->when retrnsmt   uid  timeout inode                                                     
   0: AC00F00A:C9FA C2906714:6989 01 00000000:00000000 02:00000DA9 00000000  1001        0 376439162 2 0000000000000000 21 4 0 10 -1                 
   1: AC00F00A:CA00 C2906714:6989 01 00000000:00000000 02:00000E76 00000000  1001        0 376439811 2 0000000000000000 21 4 0 10 -1                 
   2: AC00F00A:8ED0 C2906714:6989 01 00000000:00000000 02:000004DA 00000000  1001        0 445806350 2 0000000000000000 21 4 30 10 -1                
   3: AC00F00A:CA02 C2906714:6989 01 00000000:00000000 02:000000DD 00000000  1001        0 376439812 2 0000000000000000 21 4 0 10 -1                 
   4: AC00F00A:C9FE C2906714:6989 01 00000000:00000000 02:00000DA9 00000000  1001        0 376439810 2 0000000000000000 21 4 0 10 -1                 
   5: AC00F00A:8760 C2906714:6989 01 00000000:00000000 02:00000810 00000000  1001        0 375803096 2 0000000000000000 21 4 0 10 -1                 
   6: AC00F00A:C9FC C2906714:6989 01 00000000:00000000 02:00000DA9 00000000  1001        0 376439809 2 0000000000000000 21 4 0 10 -1                 
   7: AC00F00A:C56C C2906714:6989 01 00000000:00000000 02:00000DA9 00000000  1001        0 376167298 2 0000000000000000 21 4 0 10 -1                 
   8: AC00F00A:883C C2906714:6989 01 00000000:00000000 02:00000734 00000000  1001        0 375823415 2 0000000000000000 21 4 30 10 -1 
OK, that s less appealing that netstat output. The trick is that rem_address and port are expressed in hexa. A quick calculation confirms the port 0x6989 is indeed port 27017, which is the listening port of MongoDB server. So the number of opened MongoDB connections is given by:
$ kubectl -n prod exec redacted-pod-name-69875496f8-8bj4f -- cat /proc/1/net/tcp   grep :6989   wc -l
9
What s next ? The ideal solution would be to fix the NodeJS code to handle correctly the termination of the connections, but that would have taken too long to develop. So I ve written a small Perl script to: Why restart a deployment instead of simply deleting the gluttonous pods? I wanted to avoid downtime if all pods of a deployment were to be killed. There s no downtime when applying rollout restart command on deployments. This script is now run regularly until the connections issue is fixed for good in NodeJS code. Thanks to this script, there s no need to rush a code modification. All in all, working around this connections issues was made somewhat easier thanks to:

27 July 2022

Vincent Bernat: ClickHouse SF Bay Area Meetup: Akvorado

Here are the slides I presented for a ClickHouse SF Bay Area Meetup in July 2022, hosted by Altinity. They are about Akvorado, a network flow collector and visualizer, and notably on how it relies on ClickHouse, a column-oriented database.
The meetup was recorded and available on YouTube. Here is the part relevant to my presentation, with subtitles:1
I got a few questions about how to get information from the higher layers, like HTTP. As my use case for Akvorado was at the network edge, my answers were mostly negative. However, as sFlow is extensible, when collecting flows from Linux servers instead, you could embed additional data and they could be exported as well. I also got a question about doing aggregation in a single table. ClickHouse can aggregate automatically data using TTL. My answer for not doing that is partial. There is another reason: the retention periods of the various tables may overlap. For example, the main table keeps data for 15 days, but even in these 15 days, if I do a query on a 12-hour window, it is faster to use the flows_1m0s aggregated table, unless I request something about ports and IP addresses.

  1. To generate the subtitles, I have used Amazon Transcribe, the speech-to-text solution from Amazon AWS. Unfortunately, there is no en-FR language available, which would have been useful for my terrible accent. While the subtitles were 100% accurate when the host, Robert Hodge from Altinity, was speaking, the success rate on my talk was quite lower. I had to rewrite almost all sentences. However, using speech-to-text is still useful to get the timings, as it is also something requiring a lot of work to do manually.

23 July 2022

Wouter Verhelst: Planet Grep now running PtLink

Almost 2 decades ago, Planet Debian was created using the "planetplanet" RSS aggregator. A short while later, I created Planet Grep using the same software. Over the years, the blog aggregator landscape has changed a bit. First of all, planetplanet was abandoned, forked into Planet Venus, and then abandoned again. Second, the world of blogging (aka the "blogosphere") has disappeared much, and the more modern world uses things like "Social Networks", etc, making blogs less relevant these days. A blog aggregator community site is still useful, however, and so I've never taken Planet Grep down, even though over the years the number of blogs that was carried on Planet Grep has been reducing. In the past almost 20 years, I've just run Planet Grep on my personal server, upgrading its Debian release from whichever was the most recent stable release in 2005 to buster, never encountering any problems. That all changed when I did the upgrade to Debian bullseye, however. Planet Venus is a Python 2 application, which was never updated to Python 3. Since Debian bullseye drops support for much of Python 2, focusing only on Python 3 (in accordance with python upstream's policy on the matter), that means I have had to run Planet Venus from inside a VM for a while now, which works as a short-term solution but not as a long-term one. Although there are other implementations of blog aggregation software out there, I wanted to stick with something (mostly) similar. Additionally, I have been wanting to add functionality to it to also pull stuff from Social Networks, where possible (and legal, since some of these have... scary Terms Of Use documents). So, as of today, Planet Grep is no longer powered by Planet Venus, but instead by PtLink. Rather than Python, it was written in Perl (a language with which I am more familiar), and there are plans for me to extend things in ways that have little to do with blog aggregation anymore... There are a few other Planets out there that also use Planet Venus at this point -- Planet Debian and Planet FSFE are two that I'm currently already aware of, but I'm sure there might be more, too. At this point, PtLink is not yet on feature parity with Planet Venus -- as shown by the fact that it can't yet build either Planet Debian or Planet FSFE successfully. But I'm not stopping my development here, and hopefully I'll have something that successfully builds both of those soon, too. As a side note, PtLink is not intended to be bug compatible with Planet Venus. For one example, the configuration for Planet Grep contains an entry for Frederic Descamps, but somehow Planet Venus failed to fetch his feed. With the switch to PtLink, that seems fixed, and now some entries from Frederic seem to appear. I'm not going to be "fixing" that feature... but of course there might be other issues that will appear. If that's the case, let me know. If you're reading this post through Planet Grep, consider this a public service announcement for the possibility (hopefully a remote one) of minor issues.

20 July 2022

Enrico Zini: Deconstruction of the DAM hat

Further reading Talk notes Intro Debian Account Managers Responsibility for official membership What DAM is not Unexpected responsibilities DAM warnings DAM warnings? House rules Interpreting house rules Governance by bullying How about the Community Team? How about DAM? How about the DPL? Concentrating responsibility Empowering developers What needs to happen

19 July 2022

Craig Small: Linux Memory Statistics

Pretty much everyone who has spent some time on a command line in Linux would have looked at the free command. This command provides some overall statistics on the memory and how it is used. Typical output looks something like this:
             total        used        free      shared  buff/cache  available
Mem:      32717924     3101156    26950016      143608     2666752  29011928
Swap:      1000444           0     1000444
Memory sits in the first row after the headers then we have the swap statistics. Most of the numbers are directly fetched from the procfs file /proc/meminfo which are scaled and presented to the user. A good example of a simple stat is total, which is just the MemTotal row located in that file. For the rest of this post, I ll make the rows from /proc/meminfo have an amber background. What is Free, and what is Used? While you could say that the free value is also merely the MemFree row, this is where Linux memory statistics start to get odd. While that value is indeed what is found for MemFree and not a calculated field, it can be misleading. Most people would assume that Free means free to use, with the implication that only this amount of memory is free to use and nothing more. That would also mean the used value is really used by something and nothing else can use it. In the early days of free and Linux statistics in general that was how it looked. Used is a calculated field (there is no MemUsed row) and was, initially, Total - Free. The problem was, Used also included Buffers and Cached values. This meant that it looked like Linux was using a lot of memory for something. If you read old messages before 2002 that are talking about excessive memory use, they quite likely are looking at the values printed by free. The thing was, under memory pressure the kernel could release Buffers and Cached for use. Not all of the storage but some of it so it wasn t all used. To counter this, free showed a row between Memory and Swap with Used having Buffers and Cached removed and Free having the same values added:
             total       used       free     shared    buffers     cached
Mem:      32717924    6063648   26654276          0     313552    2234436
-/+ buffers/cache:    3515660   29202264
Swap:      1000444          0    1000444
You might notice that this older version of free from around 2001 shows buffers and cached separately and there s no available column (we ll get to Available later.) Shared appears as zero because the old row was labelled MemShared and not Shmem which was changed in Linux 2.6 and I m running a system way past that version. It s not ideal, you can say that the amount of free memory is something above 26654276 and below 29202264 KiB but nothing more accurate. buffers and cached are almost never all-used or all-unused so the real figure is not either of those numbers but something in-between. Cached, just not for Caches That appeared to be an uneasy truce within the Linux memory statistics world for a while. By 2014 we realised that there was a problem with Cached. This field used to have the memory used for a cache for files read from storage. While this value still has that component, it was also being used for tmpfs storage and the use of tmpfs went from an interesting idea to being everywhere. Cheaper memory meant larger tmpfs partitions went from a luxury to something everyone was doing. The problem is with large files put into a tmpfs partition the Free would decrease, but so would Cached meaning the free column in the -/+ row would not change much and understate the impact of files in tmpfs. Lucky enough in Linux 2.6.32 the developers added a Shmem row which was the amount of memory used for shmem and tmpfs. Subtracting that value from Cached gave you the real cached value which we call main_cache and very briefly this is what the cached value would show in free. However, this caused further problems because not all Shem can be reclaimed and reused and probably swapped one set of problematic values for another. It did however prompt the Linux kernel community to have a look at the problem. Enter Available There was increasing awareness of the issues with working out how much memory a system has free within the kernel community. It wasn t just the output of free or the percentage values in top, but load balancer or workload placing systems would have their own view of this value. As memory management and use within the Linux kernel evolved, what was or wasn t free changed and all the userland programs were expected somehow to keep up. The kernel developers realised the best place to get an estimate of the memory not used was in the kernel and they created a new memory statistic called Available. That way if how the memory is used or set to be unreclaimable they could change it and userland programs would go along with it. procps has a fallback for this value and it s a pretty complicated setup.
  1. Find the min_free_kybtes setting in sysfs which is the minimum amount of free memory the kernel will handle
  2. Add a 25% to this value (e.g. if it was 4000 make it 5000), this is the low watermark
  3. To find available, start with MemFree and subtract the low watermark
  4. If half of both Inactive(file) and Active(file) values are greater than the low watermark, add that half value otherwise add the sum of the values minus the low watermark
  5. If half of Slab Claimable is greater than the low watermark, add that half value otherwise add Slab Claimable minus the low watermark
  6. If what you get is less than zero, make available zero
  7. Or, just look at Available in /proc/meminfo
For the free program, we added the Available value and the +/- line was removed. The main_cache value was Cached + Slab while Used was calculated as Total - Free - main_cache - Buffers. This was very close to what the Used column in the +/- line used to show. What s on the Slab? The next issue that came across was the use of slabs. At this point, main_cache was Cached + Slab, but Slab consists of reclaimable and unreclaimable components. One part of Slab can be used elsewhere if needed and the other cannot but the procps tools treated them the same. The Used calculation should not subtract SUnreclaim from the Total because it is actually being used. So in 2015 main_cache was changed to be Cached + SReclaimable. This meant that Used memory was calculated as Total - Free - Cached - SReclaimable - Buffers. Revenge of tmpfs and the return of Available The tmpfs impacting Cached was still an issue. If you added a 10MB file into a tmpfs partition, then Free would reduce by 10MB and Cached would increase by 10MB meaning Used stayed unchanged even though 10MB had gone somewhere. It was time to retire the complex calculation of Used. For procps 4.0.1 onwards, Used now means not available . We take the Total memory and subtract the Available memory. This is not a perfect setup but it is probably going to be the best one we have and testing is giving us much more sensible results. It s also easier for people to understand (take the total value you see in free, then subtract the available value). What does that mean for main_cache which is part of the buff/cache value you see? As this value is no longer in the used memory calculation, it is less important. Should it also be reverted to simply Cached without the reclaimable Slabs? The calculated fields In summary, what this means for the calculated fields in procps at least is: Almost everything else, with the exception of some bounds checking, is what you get out of /proc/meminfo which is straight from the kernel.

17 July 2022

Russ Allbery: Review: Trang

Review: Trang, by Mary Sisson
Series: Trang #1
Publisher: Mary Sisson
Copyright: 2011
Printing: December 2013
ASIN: B004I6DAQ8
Format: Kindle
Pages: 374
In 2113, a radio mapping satellite near the Titan station disappeared. It then reappeared five days later, apparently damaged and broadcasting a signal that made computers crash. The satellite was immediately sent back to the Space Authority base in Beijing for careful examination, but the techs on the station were able to decode the transmission: a request for the contents of databases. The general manager of the station sent a probe to the same location and it too vanished, returning two days later with a picture of a portal, followed shortly by an alien probe. Five years later, Philippe Trang has been assigned as the first human diplomat to an alien space station in intergalactic space at the nexus of multiple portals. Humans will apparently be the eighth type of intelligent life to send a representative to the station. He'll have a translation system, a security detail, and the groundwork of five years of audiovisual communications with the aliens, including one that was able to learn English. But he'll be the first official diplomatic representative physically there. The current style in SF might lead you to expect a tense thriller full of nearly incomprehensible aliens, unexplained devices, and creepy mysteries. This is not that sort of book. The best comparison point I could think of is James White's Sector General novels, except with a diplomat rather than a doctor. The aliens are moderately strange (not just humans in prosthetic makeup), but are mostly earnest, well-meaning, and welcoming. Trang's security escort is more military than he expects, but that becomes a satisfying negotiation rather than an ongoing problem. There is confusion, misunderstandings, and even violence, but most of it is sorted out by earnest discussion and attempts at mutual understanding. This is, in other words, diplomat competence porn (albeit written by someone who is not a diplomat, so I wouldn't expect too much realism). Trang defuses rather than confronts, patiently sorts through the nuances of a pre-existing complex dynamic between aliens without prematurely picking sides, and has the presence of mind to realize that the special forces troops assigned to him are another culture he needs to approach with the same skills. Most of the book is low-stakes confusion, curiosity, and careful exploration, which could have been boring but wasn't. It helps that Sisson packs a lot of complexity into the station dynamics and reveals it in ways that I found enjoyably unpredictable. Some caveats: This is a self-published first novel (albeit by an experienced reporter and editor) and it shows. The book has a sort of plastic Technicolor feel that I sometimes see in self-published novels, where the details aren't quite deep enough, the writing isn't quite polished, and the dialog isn't quite as tight as I'm used to. It also meanders in a way that few commercial novels do, including slice-of-life moments and small asides that don't go anywhere. This can be either a bug or a feature depending on what you're in the mood for. I found it relaxing and stress-relieving, which is what I was looking for, but you may have a different experience. I will warn that the climax features a sudden escalation of stakes that I don't think was sufficiently signaled by the tone of the writing, and thus felt a bit unreal. Sisson also includes a couple deus ex machina twists that felt a bit predictable and easy, and I didn't find the implied recent history of one of the alien civilizations that believable. The conclusion is therefore not the strongest part of the book; if you're not enjoying the journey, it probably won't get better. But, all that said, this was fun, and I've already bought the second book in the series. It's low-stakes, gentle SF with a core of discovery and exploration rather than social dynamics, and I haven't run across much of that recently. The worst thing in the book is some dream glimpses at a horrific event in Trang's past that's never entirely on camera. It's not as pacifist as James White, but it's close. Recommended, especially if you liked Sector General. White's series is so singular that I previously would have struggled to find a suggestion for someone who wanted more exactly like that (but without the Bewitched-era sexism). Now I have an answer. Score another one for Susan Stepney, who is also how I found Julie Czerneda. Trang is also currently free for Kindle, so you can't beat the price. Followed by Trust. Rating: 8 out of 10

15 July 2022

Steve Kemp: So we come to Lisp

Recently I've been working with simple/trivial scripting languages, and I guess I finally reached a point where I thought "Lisp? Why not". One of the reasons for recent experimentation was thinking about the kind of minimalism that makes implementing a language less work - being able to actually use the language to write itself. FORTH is my recurring example, because implementing it mostly means writing a virtual machine which consists of memory ("cells") along with a pair of stacks, and some primitives for operating upon them. Once you have that groundwork in place you can layer the higher-level constructs (such as "for", "if", etc). Lisp allows a similar approach, albeit with slightly fewer low-level details required, and far less tortuous thinking. Lisp always feels higher-level to me anyway, given the explicit data-types ("list", "string", "number", etc). Here's something that works in my toy lisp:
;; Define a function,  fact , to calculate factorials (recursively).
(define fact (lambda (n)
  (if (<= n 1)
    1
      (* n (fact (- n 1))))))
;; Invoke the factorial function, using apply
(apply (list 1 2 3 4 5 6 7 8 9 10)
  (lambda (x)
    (print "%s! => %s" x (fact x))))
The core language doesn't have helpful functions to filter lists, or build up lists by applying a specified function to each member of a list, but adding them is trivial using the standard car, cdr, and simple recursion. That means you end up writing lots of small functions like this:
(define zero? (lambda (n) (if (= n 0) #t #f)))
(define even? (lambda (n) (if (zero? (% n 2)) #t #f)))
(define odd?  (lambda (n) (! (even? n))))
(define sq    (lambda (x) (* x x)))
Once you have them you can use them in a way that feels simple and natural:
(print "Even numbers from 0-10: %s"
  (filter (nat 11) (lambda (x) (even? x))))
(print "Squared numbers from 0-10: %s"
  (map (nat 11) (lambda (x) (sq x))))
This all feels very sexy and simple, because the implementations of map, apply, filter are all written using the lisp - and they're easy to write. Lisp takes things further than some other "basic" languages because of the (infamous) support for Macros. But even without them writing new useful functions is pretty simple. Where things struggle? I guess I don't actually have a history of using lisp to actually solve problems - although it's great for configuring my editor.. Anyway I guess the journey continues. Having looked at the obvious "minimal core" languages I need to go further afield: I'll make an attempt to look at some of the esoteric programming languages, and see if any of those are fun to experiment with.

13 July 2022

Dirk Eddelbuettel: rfoaas 2.3.2: New upstream accessors

rfoaas greed example FOAAS by now moved to version 2.3.2 in its repo. This releases 2.3.2 of rfoaas catches up, and brings the first release in about two and a half years. This 2.3.2 release of FOAAS brings us six new REST access points: absolutely(), dense(), dumbledore(), lowpoly(), understand(), and yeah(). Along with these new functions, documentation and tests were updated. My CRANberries service provides a diff to the previous CRAN release. Questions, comments etc should go to the GitHub issue tracker. More background information is on the project page as well as on the github repo 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.

Reproducible Builds: Reproducible Builds in June 2022

Welcome to the June 2022 report from the Reproducible Builds project. In these reports, we outline the most important things that we have been up to over the past month. As a quick recap, whilst anyone may inspect the source code of free software for malicious flaws, almost all software is distributed to end users as pre-compiled binaries.

Save the date! Despite several delays, we are pleased to announce dates for our in-person summit this year: November 1st 2022 November 3rd 2022
The event will happen in/around Venice (Italy), and we intend to pick a venue reachable via the train station and an international airport. However, the precise venue will depend on the number of attendees. Please see the announcement mail from Mattia Rizzolo, and do keep an eye on the mailing list for further announcements as it will hopefully include registration instructions.

News David Wheeler filed an issue against the Rust programming language to report that builds are not reproducible because full path to the source code is in the panic and debug strings . Luckily, as one of the responses mentions: the --remap-path-prefix solves this problem and has been used to great effect in build systems that rely on reproducibility (Bazel, Nix) to work at all and that there are efforts to teach cargo about it here .
The Python Security team announced that:
The ctx hosted project on PyPI was taken over via user account compromise and replaced with a malicious project which contained runtime code which collected the content of os.environ.items() when instantiating Ctx objects. The captured environment variables were sent as a base64 encoded query parameter to a Heroku application [ ]
As their announcement later goes onto state, version-pinning using hash-checking mode can prevent this attack, although this does depend on specific installations using this mode, rather than a prevention that can be applied systematically.
Developer vanitasvitae published an interesting and entertaining blog post detailing the blow-by-blow steps of debugging a reproducibility issue in PGPainless, a library which aims to make using OpenPGP in Java projects as simple as possible . Whilst their in-depth research into the internals of the .jar may have been unnecessary given that diffoscope would have identified the, it must be said that there is something to be said with occasionally delving into seemingly low-level details, as well describing any debugging process. Indeed, as vanitasvitae writes:
Yes, this would have spared me from 3h of debugging But I probably would also not have gone onto this little dive into the JAR/ZIP format, so in the end I m not mad.

Kees Cook published a short and practical blog post detailing how he uses reproducibility properties to aid work to replace one-element arrays in the Linux kernel. Kees approach is based on the principle that if a (small) proposed change is considered equivalent by the compiler, then the generated output will be identical but only if no other arbitrary or unrelated changes are introduced. Kees mentions the fantastic diffoscope tool, as well as various kernel-specific build options (eg. KBUILD_BUILD_TIMESTAMP) in order to prepare my build with the known to disrupt code layout options disabled .
Stefano Zacchiroli gave a presentation at GDR S curit Informatique based in part on a paper co-written with Chris Lamb titled Increasing the Integrity of Software Supply Chains. (Tweet)

Debian In Debian in this month, 28 reviews of Debian packages were added, 35 were updated and 27 were removed this month adding to our knowledge about identified issues. Two issue types were added: nondeterministic_checksum_generated_by_coq and nondetermistic_js_output_from_webpack. After Holger Levsen found hundreds of packages in the bookworm distribution that lack .buildinfo files, he uploaded 404 source packages to the archive (with no meaningful source changes). Currently bookworm now shows only 8 packages without .buildinfo files, and those 8 are fixed in unstable and should migrate shortly. By contrast, Debian unstable will always have packages without .buildinfo files, as this is how they come through the NEW queue. However, as these packages were not built on the official build servers (ie. they were uploaded by the maintainer) they will never migrate to Debian testing. In the future, therefore, testing should never have packages without .buildinfo files again. Roland Clobus posted yet another in-depth status report about his progress making the Debian Live images build reproducibly to our mailing list. In this update, Roland mentions that all major desktops build reproducibly with bullseye, bookworm and sid but also goes on to outline the progress made with automated testing of the generated images using openQA.

GNU Guix Vagrant Cascadian made a significant number of contributions to GNU Guix: Elsewhere in GNU Guix, Ludovic Court s published a paper in the journal The Art, Science, and Engineering of Programming called Building a Secure Software Supply Chain with GNU Guix:
This paper focuses on one research question: how can [Guix]((https://www.gnu.org/software/guix/) and similar systems allow users to securely update their software? [ ] Our main contribution is a model and tool to authenticate new Git revisions. We further show how, building on Git semantics, we build protections against downgrade attacks and related threats. We explain implementation choices. This work has been deployed in production two years ago, giving us insight on its actual use at scale every day. The Git checkout authentication at its core is applicable beyond the specific use case of Guix, and we think it could benefit to developer teams that use Git.
A full PDF of the text is available.

openSUSE In the world of openSUSE, SUSE announced at SUSECon that they are preparing to meet SLSA level 4. (SLSA (Supply chain Levels for Software Artifacts) is a new industry-led standardisation effort that aims to protect the integrity of the software supply chain.) However, at the time of writing, timestamps within RPM archives are not normalised, so bit-for-bit identical reproducible builds are not possible. Some in-toto provenance files published for SUSE s SLE-15-SP4 as one result of the SLSA level 4 effort. Old binaries are not rebuilt, so only new builds (e.g. maintenance updates) have this metadata added. Lastly, Bernhard M. Wiedemann posted his usual monthly openSUSE reproducible builds status report.

diffoscope diffoscope is our in-depth and content-aware diff utility. Not only can it locate and diagnose reproducibility issues, it can provide human-readable diffs from many kinds of binary formats. This month, Chris Lamb prepared and uploaded versions 215, 216 and 217 to Debian unstable. Chris Lamb also made the following changes:
  • New features:
    • Print profile output if we were called with --profile and we were killed via a TERM signal. This should help in situations where diffoscope is terminated due to some sort of timeout. [ ]
    • Support both PyPDF 1.x and 2.x. [ ]
  • Bug fixes:
    • Also catch IndexError exceptions (in addition to ValueError) when parsing .pyc files. (#1012258)
    • Correct the logic for supporting different versions of the argcomplete module. [ ]
  • Output improvements:
    • Don t leak the (likely-temporary) pathname when comparing PDF documents. [ ]
  • Logging improvements:
    • Update test fixtures for GNU readelf 2.38 (now in Debian unstable). [ ][ ]
    • Be more specific about the minimum required version of readelf (ie. binutils), as it appears that this patch level version change resulted in a change of output, not the minor version. [ ]
    • Use our @skip_unless_tool_is_at_least decorator (NB. at_least) over @skip_if_tool_version_is (NB. is) to fix tests under Debian stable. [ ]
    • Emit a warning if/when we are handling a UNIX TERM signal. [ ]
  • Codebase improvements:
    • Clarify in what situations the main finally block gets called with respect to TERM signal handling. [ ]
    • Clarify control flow in the diffoscope.profiling module. [ ]
    • Correctly package the scripts/ directory. [ ]
In addition, Edward Betts updated a broken link to the RSS on the diffoscope homepage and Vagrant Cascadian updated the diffoscope package in GNU Guix [ ][ ][ ].

Upstream patches The Reproducible Builds project detects, dissects and attempts to fix as many currently-unreproducible packages as possible. We endeavour to send all of our patches upstream where appropriate. This month, we wrote a large number of such patches, including:

Testing framework The Reproducible Builds project runs a significant testing framework at tests.reproducible-builds.org, to check packages and other artifacts for reproducibility. This month, the following changes were made:
  • Holger Levsen:
    • Add a package set for packages that use the R programming language [ ] as well as one for Rust [ ].
    • Improve package set matching for Python [ ] and font-related [ ] packages.
    • Install the lz4, lzop and xz-utils packages on all nodes in order to detect running kernels. [ ]
    • Improve the cleanup mechanisms when testing the reproducibility of Debian Live images. [ ][ ]
    • In the automated node health checks, deprioritise the generic kernel warning . [ ]
  • Roland Clobus (Debian Live image reproducibility):
    • Add various maintenance jobs to the Jenkins view. [ ]
    • Cleanup old workspaces after 24 hours. [ ]
    • Cleanup temporary workspace and resulting directories. [ ]
    • Implement a number of fixes and improvements around publishing files. [ ][ ][ ]
    • Don t attempt to preserve the file timestamps when copying artifacts. [ ]
And finally, node maintenance was also performed by Mattia Rizzolo [ ].

Mailing list and website On our mailing list this month: Lastly, Chris Lamb updated the main Reproducible Builds website and documentation in a number of small ways, but primarily published an interview with Hans-Christoph Steiner of the F-Droid project. Chris Lamb also added a Coffeescript example for parsing and using the SOURCE_DATE_EPOCH environment variable [ ]. In addition, Sebastian Crane very-helpfully updated the screenshot of salsa.debian.org s request access button on the How to join the Salsa group. [ ]

Contact If you are interested in contributing to the Reproducible Builds project, please visit our Contribute page on our website. However, you can get in touch with us via:

12 July 2022

Matthew Garrett: Responsible stewardship of the UEFI secure boot ecosystem

After I mentioned that Lenovo are now shipping laptops that only boot Windows by default, a few people pointed to a Lenovo document that says:

Starting in 2022 for Secured-core PCs it is a Microsoft requirement for the 3rd Party Certificate to be disabled by default.

"Secured-core" is a term used to describe machines that meet a certain set of Microsoft requirements around firmware security, and by and large it's a good thing - devices that meet these requirements are resilient against a whole bunch of potential attacks in the early boot process. But unfortunately the 2022 requirements don't seem to be publicly available, so it's difficult to know what's being asked for and why. But first, some background.

Most x86 UEFI systems that support Secure Boot trust at least two certificate authorities:

1) The Microsoft Windows Production PCA - this is used to sign the bootloader in production Windows builds. Trusting this is sufficient to boot Windows.
2) The Microsoft Corporation UEFI CA - this is used by Microsoft to sign non-Windows UEFI binaries, including built-in drivers for hardware that needs to work in the UEFI environment (such as GPUs and network cards) and bootloaders for non-Windows.

The apparent secured-core requirement for 2022 is that the second of these CAs should not be trusted by default. As a result, drivers or bootloaders signed with this certificate will not run on these systems. This means that, out of the box, these systems will not boot anything other than Windows[1].

Given the association with the secured-core requirements, this is presumably a security decision of some kind. Unfortunately, we have no real idea what this security decision is intended to protect against. The most likely scenario is concerns about the (in)security of binaries signed with the third-party signing key - there are some legitimate concerns here, but I'm going to cover why I don't think they're terribly realistic.

The first point is that, from a boot security perspective, a signed bootloader that will happily boot unsigned code kind of defeats the point. Kaspersky did it anyway. The second is that even a signed bootloader that is intended to only boot signed code may run into issues in the event of security vulnerabilities - the Boothole vulnerabilities are an example of this, covering multiple issues in GRUB that could allow for arbitrary code execution and potential loading of untrusted code.

So we know that signed bootloaders that will (either through accident or design) execute unsigned code exist. The signatures for all the known vulnerable bootloaders have been revoked, but that doesn't mean there won't be other vulnerabilities discovered in future. Configuring systems so that they don't trust the third-party CA means that those signed bootloaders won't be trusted, which means any future vulnerabilities will be irrelevant. This seems like a simple choice?

There's actually a couple of reasons why I don't think it's anywhere near that simple. The first is that whenever a signed object is booted by the firmware, the trusted certificate used to verify that object is measured into PCR 7 in the TPM. If a system previously booted with something signed with the Windows Production CA, and is now suddenly booting with something signed with the third-party UEFI CA, the values in PCR 7 will be different. TPMs support "sealing" a secret - encrypting it with a policy that the TPM will only decrypt it if certain conditions are met. Microsoft make use of this for their default Bitlocker disk encryption mechanism. The disk encryption key is encrypted by the TPM, and associated with a specific PCR 7 value. If the value of PCR 7 doesn't match, the TPM will refuse to decrypt the key, and the machine won't boot. This means that attempting to attack a Windows system that has Bitlocker enabled using a non-Windows bootloader will fail - the system will be unable to obtain the disk unlock key, which is a strong indication to the owner that they're being attacked.

The second is that this is predicated on the idea that removing the third-party bootloaders and drivers removes all the vulnerabilities. In fact, there's been rather a lot of vulnerabilities in the Windows bootloader. A broad enough vulnerability in the Windows bootloader is arguably a lot worse than a vulnerability in a third-party loader, since it won't change the PCR 7 measurements and the system will boot happily. Removing trust in the third-party CA does nothing to protect against this.

The third reason doesn't apply to all systems, but it does to many. System vendors frequently want to ship diagnostic or management utilities that run in the boot environment, but would prefer not to have to go to the trouble of getting them all signed by Microsoft. The simple solution to this is to ship their own certificate and sign all their tooling directly - the secured-core Lenovo I'm looking at currently is an example of this, with a Lenovo signing certificate. While everything signed with the third-party signing certificate goes through some degree of security review, there's no requirement for any vendor tooling to be reviewed at all. Removing the third-party CA does nothing to protect the user against the code that's most likely to contain vulnerabilities.

Obviously I may be missing something here - Microsoft may well have a strong technical justification. But they haven't shared it, and so right now we're left making guesses. And right now, I just don't see a good security argument.

But let's move on from the technical side of things and discuss the broader issue. The reason UEFI Secure Boot is present on most x86 systems is that Microsoft mandated it back in 2012. Microsoft chose to be the only trusted signing authority. Microsoft made the decision to assert that third-party code could be signed and trusted.

We've certainly learned some things since then, and a bunch of things have changed. Third-party bootloaders based on the Shim infrastructure are now reviewed via a community-managed process. We've had a productive coordinated response to the Boothole incident, which also taught us that the existing revocation strategy wasn't going to scale. In response, the community worked with Microsoft to develop a specification for making it easier to handle similar events in future. And it's also worth noting that after the initial Boothole disclosure was made to the GRUB maintainers, they proactively sought out other vulnerabilities in their codebase rather than simply patching what had been reported. The free software community has gone to great lengths to ensure third-party bootloaders are compatible with the security goals of UEFI Secure Boot.

So, to have Microsoft, the self-appointed steward of the UEFI Secure Boot ecosystem, turn round and say that a bunch of binaries that have been reviewed through processes developed in negotiation with Microsoft, implementing technologies designed to make management of revocation easier for Microsoft, and incorporating fixes for vulnerabilities discovered by the developers of those binaries who notified Microsoft of these issues despite having no obligation to do so, and which have then been signed by Microsoft are now considered by Microsoft to be insecure is, uh, kind of impolite? Especially when unreviewed vendor-signed binaries are still considered trustworthy, despite no external review being carried out at all.

If Microsoft had a set of criteria used to determine whether something is considered sufficiently trustworthy, we could determine which of these we fell short on and do something about that. From a technical perspective, Microsoft could set criteria that would allow a subset of third-party binaries that met additional review be trusted without having to trust all third-party binaries[2]. But, instead, this has been a decision made by the steward of this ecosystem without consulting major stakeholders.

If there are legitimate security concerns, let's talk about them and come up with solutions that fix them without doing a significant amount of collateral damage. Don't complain about a vendor blocking your apps and then do the same thing yourself.

[Edit to add: there seems to be some misunderstanding about where this restriction is being imposed. I bought this laptop because I'm interested in investigating the Microsoft Pluton security processor, but Pluton is not involved at all here. The restriction is being imposed by the firmware running on the main CPU, not any sort of functionality implemented on Pluton]

[1] They'll also refuse to run any drivers that are stored in flash on Thunderbolt devices, which means eGPU setups may be more complicated, as will netbooting off Thunderbolt-attached NICs
[2] Use a different leaf cert to sign the new trust tier, add the old leaf cert to dbx unless a config option is set, leave the existing intermediate in db

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