etbe - Russell Coker

Links March 2022

Anarcat wrote a great blog post about switching from OpenNTP to Chrony which gives a good overview of how NTP works and how accurate the different versions are [1].

Bleeping Computer has an amusing article about criminals who copied a lot of data from NVidia servers including specs of their latest products [2], they are threatening to release all the data if NVidia doesn’t stop crippling their GPUs to make them unsuitable for crypto currency mining. I don’t support these criminals, but I think NVidia should allow people who buy hardware to use their property as they choose. If cryptocurrency miners buy all the NVidia products then NVidia still makes the sales, they could even auction them to make more money.

NPR has a disturbing article about the way execution by lethal injection works in the US [3]. It seems that most people die in an extremely unpleasant way. It makes the North Korean execution by anti-aircraft gun seem civilised.

The DirtyPipe vulnerability is the latest serious security issue in the Linux kernel [4]. The report of how it was discovered is very interesting and should be read by all sysadmins. SE Linux will not save you from this as the vulnerability allows writing to read-only files like /etc/passwd.

Politico has an insightful analysis of Putin, it’s not good news he wants to conquer all territory that had ever been part of a Russian empire at any time in history [5].

The Guardian has an informative article about the EU’s attempts to debunk Russian propaganda about Covid19 [6]. Fortunately the sanctions are reducing Russia’s ability to do such things now.

The Guardian has in interesting article about a project to use literary analysis to predict wars [7]. Funded by the German military but funding was cut after it was proven to work.

The Fact Act is a proposal by David Brin for political changes in the US to involve scientists and statisticians in an official advisory role in the legislative process [8], it’s an idea with a lot of potential.

Technology Review has an interesting interview with the leader of the NSA’s Research Directorate [9].

In 2008 the EFF posted a long and informative article about the RIAA’s war against music fans [10]. I had followed a lot of the news about this when it was happening, but I still learnt some things from this article that I hadn’t known at the time. Also considering past legal battles in the context of the current situation is useful. As an aside all the music I want to listen to is now on YouTube and youtube-dl works really well for me.

The 1952 edition of Psychiatry: Journal of Interpersonal Relations has an interesting article On Cooling the Mark Out [11] which starts about how criminal gangs engaged in fraud try to make their victims come to terms with the loss in a way that doesn’t involve the police. But it goes on to cover ways of dealing with loss of status in general. The layout is hacky with words broken by hyphens in the middle of lines as it appears to have been scanned from paper, converted to MS-Word, and from there to PDF. But it’s worth it.

The Internet Heist by Cory Doctorow is an insightful series of 3 articles about the MPAA (MAFIAA) attempts to take over all TV distribution in the US [12].

Wired has an interesting exerpt from the book “Spies, Lies, and Algorithms: The History and Future of American Intelligence”, by Amy B. Zegart [13]. Interesting summary of the “open source intelligence” systems (which have nothing to do with “open source” as free software). But it would be interesting to have an “open source” intelligence organisation along similar lines to “open source” software. The guy who tracks billionaire’s private jets is an example of this.

Feedburner Seems to be Dying

Many years ago Feedburner was a useful service. It proxied the RSS feed of your blog and gave you analytics of what happened with it. Now feeds using Feedburner randomly give HTTP error 404s. The Feedburner Twitter account is inactive and recommends that people Tweet at Google instead. It seems that Google wants to get rid of the service and random 404s probably aren’t a high priority for them.

I’ve just gone through the config for Planet Linux Australia [1] and changed as many Feedburner URLs as possible to direct feed URLs. I did this by loading the Feedburner feed, getting the URL for the site, and then guessing the feed URL (usually just appending “/feed” to the domain name).

I recommend that everyone abandon Feedburner, it’s not reliable enough to use and doesn’t seem to have any active support.

[1] https://planet.luv.asn.au/

Hangouts Replacement

Google is currently in the process of killing Hangouts. Last year Hangouts was quite a nice IM system with integrated video chat and voice calling. Now they have decided to kill it and replace it with “Google Chat” and “Google Meet” both of which are integrated with the Gmail app on Android. To start getting people off the old platform they have disabled video and audio chats with more than 2 people in Hangouts. To do a video call you have to use Meet which has a worse user interface and isn’t integrated with text chat, so if in a text discussion someone says “let’s have a video call” you have to open a new app. Meet also doesn’t appear to have a facility to notify group members that someone has joined a group call so it’s required that Chat (or something else) is used to tell people they can join Meet.

Many of my relatives use Hangouts because they are forced to have it installed on their Android phones and because it worked quite well. Now it doesn’t work well and will soon be going away. So another option is needed.

I’m considering Matrix as a replacement. Matrix has a good feature set and is being worked on a lot. The video conferencing is through a connection to a Jitsi server and is well integrated giving functionality more like Hangouts than Chat/Meet.

For the LUV Matrix server the URL https://luv.asn.au/.well-known/matrix/client has the following contents:

{
  "m.homeserver": {
    "base_url": "https://luv.asn.au"
  }
  "jitsi": {
    "preferredDomain": "jitsi.perthchat.org"
  }
  "im.vector.riot.jitsi": {
    "preferredDomain": "jitsi.perthchat.org"
  }
}

This specifies the Jitsi server to be used for chats started from that Matrix server. The PerthChat.org people seem to be leading the way for self hosted Matrix in Australia. Note that other people shouldn’t link to their Jitsi server without discussing it with them first. I only included real data because it’s published on the web so there’s no point in keeping it secret.

The Flounder free software users’ group [1] uses Matrix a lot. We will probably discuss Matrix at the next meeting on Saturday.

There is also Element Call [2] which is apparently more integrated with Matrix (and also newer and possibly buggier). Jitsi works and we can change to a different service easily enough at a later time.

Reading Glasses

About 4 years ago at a routine eye check the optometrist recommended that I get reading glasses. Apparently I’m old enough that my eyes are losing their ability to focus at different distances to having different glasses for close and remote objects (EG reading and driving) is necessary for good vision.

The optometrist asked me the distance that I use for reading and I indicated a distance that is good for books and phones (about 20cm). So I got a pair of glasses that worked well for that but didn’t work well for the vast majority of my close work which is computer monitors. I found that I could use my reading glasses with my laptop when lying in bed if I had the laptop on my chest with the keyboard touching my chin, which is a reasonable position for watching TV but not for much else.

About 2 years ago I had another eye check which determined that the glasses for long distance were good and got reading glasses designed for objects about 80cm away which worked well for monitors and were usable for watching TV.

Recently I accidentally broke my newer pair of reading glasses and discovered that the older pair now works for distances of about a meter. So it appears that I have become significantly more long sighted over the last 4 years.

Wayland

The Wayland protocol [1] is designed to be more secure than X, when X was designed there wasn’t much thought given to the possibility of programs with different access levels displaying on the same desktop. The Xephyr nested X server [2] is good for running an entire session from a remote untrusted host on a local display but isn’t suitable for multiple applications in the same session.

GNOME supported Wayland by default in Debian since the Bullseye release and for KDE support you can install the plasma-workspace-wayland which gives you an option for the session type of KDE Plasma Wayland when you login. For systems which don’t use the KDE Plasma workspace but which have some KDE apps you should install the package qtwayland5 to allow the KDE apps to use the Wayland protocol. See the KDE page of the Debian Wiki [3] for more information.

The Debian Wiki page on Wayland has more useful information [4]. Apparently you have to use gdm instead of sddm to get Wayland for the login prompt.

To get screen sharing working on Wayland (and also to get a system that doesn’t give out error messages) you need to install the pipewire package (see the Pipewire project page for more information [6]).

Daniel Stone gave a great LCA talk about Wayland in 2013 [5].

I have just converted two of my systems to Wayland. It’s pretty uneventful, things seem to work the same way as before. It might be theoretically faster but in practice Xorg was fast enough that there’s not much possibility to appear faster. My aim is to work on Linux desktop security to try and get process isolation similar to what Android does on the PC desktop and on Debian based phones such as the Librem 5. Allowing some protection against graphics based attacks is only the first step towards that goal, but it’s an important step. More blog posts on related topics will follow.

Update: One thing I forgot to mention is that MAC systems need policy changes for Wayland. There are direct changes (allowing background daemons for GPU access to talk to a Wayland server running in a user context instead of an X server in a system context) and indirect changes (having the display server and window manager merged).

More About the Librem 5

I concluded my previous post about the Purism Librem 5 [1] with the phone working as a Debian/GNOME system with SSH access over the LAN. Before I published that post I managed to render it unbootable, making a new computer unbootable on the first day of owning it isn’t uncommon for me. In this case I tried to get SE Linux running on it and changing the kernel commandline parameter “security=apparmor” to “security=selinux” caused it to fail the checksum on kernel parameters and halt the boot. That seems to require a fresh install, it seems possible that I could setup my Librem5 to boot a recovery image from a SD card in such situations but that doesn’t seem to be well documented and I didn’t have any important data to lose. If I do figure out how to recover data by booting from a micro SD card I’ll document it.

Here’s the documentation for reflashing the phone [2], you have to use the “--variant luks” option for the flashing tool to have an encrypted root filesystem (should default to on to match the default shipping configuration). There is an option --skip-cleanup to allow you to use the same image multiple times, but that probably isn’t useful. The image that is available for download today has the latest kernel update that I installed yesterday so it seems that they quickly update the image which makes it convenient to get the latest (dpkg is slow on low power ARM systems). Overall the flash tool is nicely written, does the download and install and instructs you how to get the phone in flashing mode. It is a minor annoyance that the battery has to be removed as part of the flashing process, I will probably end up flashing my phone more often than I want to take the back off the case. A mitigating factor is that the back is well designed and doesn’t appear prone to having it’s plastic tabs breaking off when removed (as has happened to several other phones I’ve owned).

The camera doesn’t seem to work well at this time, all photos have an unusually low brightness. The audio recording also doesn’t work well, speaking clearly into the phone results in quiet recordings.

I updated the Debian Wiki page on Mobile devices [3] to include a link to a page about the Librem5 [4] and to also have a section about applications known to work well on mobile devices. Hopefully other people will make some additions to that as most programs in Debian don’t work well on mobile devices so we need a list of known good applications as well as applications that can be easily changed to work well.

One thing I’ve started looking at is the code for the Geary MUA (the default MUA for the Librem5 and the only one in Debian I know to be suitable for a phone). It needs the Thunderbird style autoconfig and it needs the ability to select which IMAP folders to scan as a common practice is to have some large IMAP folders that aren’t used on mobile devices.

I believe that Android runs each app in a separate UID to prevent them from messing with each other. The configuration on a standard Linux system and on PureOS is to have all apps running with the same permissions, I think this needs to be improved both for phones and for regular Linux systems which will probably benefit more than phones do. I’ll write another blog post about this.

Librem 5 First Impression

I just received the Purism Librem 5 that I paid for years ago (I think it was 2018). The process of getting the basic setup done was typical (choosing keyboard language, connecting to wifi, etc). Then I tried doing things. One thing I did was update to the latest PureOS release which gave me a list of the latest Debian packages installed which is nice.

The first problem I found was the lack of notification when the phone is trying to do something. I’d select to launch an app, nothing would happen, then a few seconds later it would appear. When I go to the PureOS app store and get a list of apps in a category nothing happens for ages (shows a blank list) then it might show actual apps, or it might not. I don’t know what it’s doing, maybe downloading a list of apps, if so it should display how many apps have had their summary data downloaded or how many KB of data have been downloaded so I know if it’s doing something and how long it might take.

Running any of the productivity applications requires a GNOME keyring, I selected a keyring password of a few characters and it gave a warning about having no password (does this mean it took 3 characters to be the same as 0 characters?). Then I couldn’t unlock it later. I tried deleting the key file and creating a new one with a single character password and got the same result. I think that such keyring apps have little benefit, all processes in the session have the same UID and presumable can use ptrace to get data from each other’s memory space. If the keyring program was SETGID and the directory used to store the keyring files was a system directory with execute access only for that group then it might provide some benefit (SETGID means that ptrace is denied). Ptrace is denied for the keyring but relying on a user space prompt for the passphrase to a file that the user can read seems of minimal benefit as a hostile process could read the file and prompt for the passphrase. This is probably more of a Debian issue, and I reproduced the keyring issue with my Debian workstation.

The Librem 5 is a large phone (unusually thick by modern phone standards) and is rumoured to be energy hungry. When I tried charging it from the USB port on my PC (HP ML110 Gen9) the charge level went down. I used the same USB port and USB cable that I use to charge my Huawei Mate 10 Pro every day, so other phones can draw more power from that USB port and cable faster than they use it.

The on-sceen keyboard for the Librem 5 is annoying, it doesn’t have a TAB key and the cursor control keys are unreasonably small. The keyboard used by ConnectBot (the most popular SSH client for Android) is much better, it has it’s own keys for CTRL, ESC, TAB, arrows, HOME, and END in addition to the regular on-screen keyboard. The Librem 5 comes with a terminal app by default which is much more difficult to use than it should be due to the lack of TAB filename completion etc.

The phone has a specified temperature range of 0C to 35C, that’s not great for Australia where even the cooler cities have summer temperatures higher than that. When charging on a fast charger (one that can provide energy faster than the phone uses it) the phone gets quite warm. It feels like more than 10C hotter than the ambient temperature, so I guess I can’t charge it on Monday afternoon when the forecast is 31C! Maybe I should put a USB charger by my fridge with a long enough cable that I can charge a phone that’s inside the fridge, seriously.

Having switches to disable networking is a good security feature and designing the phone with separate components that can’t interfere with each other is good too. There are reports that software fixes will reduce the electricity use which will alleviate the problems with charging and temperature. Most of my problems are clearly software related and therefore things that I can fix (in theory at least – I don’t have unlimited coding time).

Overall this wasn’t the experience I had hoped for after spending something like $700 and waiting about 4 years (so long that I can’t easily find the records of how long and how much money).

Getting It Working

It seems that the PureOS app store app doesn’t work properly. I can visit the app site and then select an app to install which then launches the app store app to do the install, which failed for every app I tried.

Then I tried going to the terminal and running the following:

sudo bash
apt update
apt install openssh-server netcat

So I should be able to use APT to install everything I want and use the PureOS web site as a guide to what is expected to work on the phone.

As an aside the PureOS apt repository appears to be a mirror or rebuild of the Debian/Bullseye arm64 archive without non-free components that they call Byzanteum.

Then I could ssh to my phone via “ssh purism@purism” (after adding an entry to /etc/hosts with the name purism and a static entry in my DHCP configuration to match) and run “sudo bash” to get root. To be able to login to root directly I had to install a ssh key (root is setup to login without password) and run “usermod --expiredate= root” (empty string for expire date) to have direct root logins.

I put the following in /etc/ssh/sshd_config.d/local.conf to restrict who can login (I added the users I want to the sshusers group). It also uses the ClientAlive checks because having sessions break due to IP address changes is really common with mobile devices and we don’t want disconnected sessions taking up memory forever.

AllowGroups sshusers
PasswordAuthentication no

UseDNS no
ClientAliveInterval 60
ClientAliveCountMax 6

Notifications

The GNOME notification system is used for notifications in the phone UI. So if you install the package libnotify-bin you get a utility notify-send that allows sending notifications from shell scripts.

Final Result

Now it basically works as a Debian workstation with a single-button mouse. So I just need to configure it as I would a Debian system and fix bugs along the way. Presumably any bug fixes I get into Debian will appear in PureOS shortly after the next Debian release.

SAGE (ITPA) Spam

In 2008 I joined SAGE (the System Administrators’ Guild of Australia). It was a professional society for people doing sysadmin work (running computer servers). I quit when I found that the level of clue was lower than hoped and that members used the code of ethics as nothing but a way to score points in online debates. After quitting SAGE kept emailing me and wouldn’t respect my request to be removed from all lists so I had to block their mail server.

SAGE has in recent times changed it’s name to ITPA (Information Technology Professionals Association) and is still sending me email. I’ve just sent yet another unsubscribe request.

How many years of sending unwanted email can be caused by incompetence and when should we assume it’s malice? They have been doing this for over a decade now. Even if it’s incompetence, that’s still damning given that it’s incompetence in the main topic of the organisation.

Here is the ITPA Code of Ethics [1], as you can see there is no reference to spam. The nearest seems to be “I will continue to enlarge my understanding of the social and legal issues that arise in computing environments, and I will communicate that understanding to others when appropriate“. So it’s great that they aren’t breaking their own code of ethics :-# but I’d still like them to stop emailing me.

[1] https://www.itpa.org.au/code-of-ethics/

Mouse and Teflon

I had a problem with my mouse. The slippery plastic bits on the bottom weren’t glued on well and came off, which then gave more friction when moving on the desk. After asking advice on a mailing list the best suggestion was Teflon sticky tape. I bought a few meters of such tape (a lifetime supply for mouse repair) and used an 8cm strip on each side of the bottom of my mouse which made it slippery enough.

Ebay seems like a good place to buy that, most of the offers are well below $20 for a reel of tape including postage. One thing to note is that they also sell non-adhesive teflon tape. I made the mistake of investigating the capabilities of teflon tape then buying the cheapest one on offer which turned out to be “plumber’s tape” which doesn’t have adhesive, fortunately it was well below $10. I now have a lifetime supply of plumber’s tape if I can ever find a use for it.

First Flounder Meeting

Based on a comment from my previous post [1] I have named the new FOSS group for Australia and NZ Flounder. Here is the link to the agenda for the first meeting [2].

I am currently using a DNS name in my own domain for the group, but in the near future I’ll move it to somewhere else under a zone I don’t control. My aim is not to have personal control but to create an organisation for the community. But at the moment I’m just doing things in the fastest way possible, I will setup HTTP redirects when I get a better DNS name.

etbe – Russell Coker

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Links March 2022

Feedburner Seems to be Dying

Hangouts Replacement

Reading Glasses

Wayland

More About the Librem 5

Librem 5 First Impression

Getting It Working

Notifications

Final Result

SAGE (ITPA) Spam

Mouse and Teflon

First Flounder Meeting

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