The Python language server is the mostsubstantial Python program I run on our servers, making it an obvious candidate to try running under PyPyfor a speedup. The last time around ,I optimistically assumed that I would use the Ubuntu packaged versionof PyPy. Unfortunately, all of our login servers are still runningUbuntu 18.04 and 18.04 has no packaged version of PyPy 3 . Since Python 3 is what I use for much ofboth my personal and our work code and you have to

OpenSSH has quite a lot of things involving keys, key types, andkey algorithms, with options to control them and ways to report onthem and so on. It can be confusing when you read manpages for ssh,ssh_config, sshd, and so on (and it has regularly confused me).It turns out that OpenSSH has a great explanation in their OpenSSHLegacy Options documentation,so great that rather than paraphrase it I am just going to quoteit (with some additional commentary):

When an

Back in 2014 I wrote about what I knew about the then-currentdifferent types of SSH keys . Things have changedaround a bit since then, so it's time for an update.

Modern versions of SSH support three different types of public keycryptography for common use; RSA, ECDSA, and Ed25519. Both ECDSAand Ed25519 use elliptic curve cryptography , while RSA is based on integer factorization . SSH once supportedDSA public key cryptography, but

Firefox has a user preferences system, exposed through its 'Settings'or 'Preferences' system (also known as about:preferences) and alsothrough the more low-level configuration editor (aka about:config) .As is mentioned there and covered in somewhat more detail in what information is in your profile ,these configuration settings (and also your preferences settings)are stored in your profile's prefs.js file.

You might think that once you manually set something in about:config,your setting will

We have long had a mix of Ubuntuversions. The short explanation is that most machines users log into (our login servers and compute servers) get upgraded every LTSversion, while other machines that are less accessible only getupgraded every other LTS (the longer version is How we handleUbuntu LTS versions ). Under normal circumstances,this would currently give us a relatively even mix of 20.04 machinesand 18.04 machines. These aren't normal times .

The result of these

OpenSSH 8.6 was recently released, and its release notes have a 'future deprecationnotice' as has every release since OpenSSH 8.2:

Future deprecation notice

It is now possible to perform chosen-prefix attacks against theSHA-1 algorithm for less than USD$50K.

In the SSH protocol, the "ssh-rsa" signature scheme uses the SHA-1hash algorithm in conjunction with the RSA public key algorithm.OpenSSH will disable this signature scheme by default in the nearfuture.

More

One of the areas of cryptography that's always seemed magical tome is symmetric ciphers. I believed that they worked, but it feltamazing that people were able to construct functions that producedrandom-looking output but that could be inverted if and only if youhad the key (and perhaps some other information, like a nonce orIV). I recently read Soatok's Understanding Extended-NonceConstructions ,which set off a sudden understanding of a general, straightforwardway to construct symmetric ciphers (although not all

We run our own primary DNSservers for DNS for our zones, bothforward zones for domains we support and reverse PTR zones for our publicsubnets. For a number of reasons, including that our networklayout means we need split-horizon DNS , we have what Iwould call a semi-stealth DNS master server; it's not listed in ourNS records, but it is listed as the master name server in our SOA records, including (ofcourse) for reverse PTR zones. External people are not

By now, we have been workingfrom home for more than a year due to ongoing world and localevents . I've woundup with complicated and tangled feelings about working from homein general, but some things about the whole experience are veryclear. Back at the start of July of 2020, I wrote about how thework we weren't able to do from home was accumulating . Some of that work has been done in the tenmonths since then, but a lot of it hasn