Jan Schaumann
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jschauma.mstdn.social.ap.brid.gy
Jan Schaumann
@jschauma.mstdn.social.ap.brid.gy
54 followers 5 following 260 posts
Vell, I'm just zis guy, you know?

[bridged from https://mstdn.social/@jschauma on the fediverse by https://fed.brid.gy/ ]
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jschauma.mstdn.social.ap.brid.gy
Amazon S3 now supports TLS 1.3 hybrid post-quantum key exchange:

https://docs.aws.amazon.com/AmazonS3/latest/userguide/UsingEncryptionInTransit.PQ-TLS.html

Note again that Amazon supports both X25519MLKEM768 _and_ SecP256r1MLKEM768.

#tls #PQC
$ </dev/null openssl s_client -curves X25519MLKEM768:X25519 \ > -connect s3.amazonaws.com:443 2>/dev/null | egrep "(Key|group)" Negotiated TLS1.3 group: X25519MLKEM768 $ $ </dev/null openssl s_client -curves SecP256r1MLKEM768:X25519MLKEM768:X25519 \ > -connect s3.amazonaws.com:443 2>/dev/null | egrep "(Key|group)" Negotiated TLS1.3 group: SecP256r1MLKEM768 $
November 23, 2025 at 4:59 PM
jschauma.mstdn.social.ap.brid.gy
Good news!: Gandi now supports HTTPS DNS records! 🎉

Bad news: Adding HTTPS DNS records breaks your auths. 🤦‍♂️
November 22, 2025 at 9:52 PM
jschauma.mstdn.social.ap.brid.gy
🎉 56 years ago today, "the first permanent ARPANET link was established between the IMP at UCLA and the IMP at the Stanford Research Institute. By 12/5 1969, the initial four-node network was established."

https://en.wikipedia.org/wiki/ARPANET

From there, it's […]

[Original post on mstdn.social]
November 21, 2025 at 5:53 PM
jschauma.mstdn.social.ap.brid.gy
Advanced Programming in the Unix Environment

Week 12: syslog(3)

In this video lecture, we take a look at the standard Unix central logging facility, syslogd(8), and the syslog(3) library function. We show examples of system logs and how to separate messages by […]

[Original post on mstdn.social]
November 19, 2025 at 9:03 PM
jschauma.mstdn.social.ap.brid.gy
Cloudflare outage root cause: not checking the return value of a function that may fail. In C, that would be calling something on NULL and segfaulting; in Rust it's calling a function on an Err val and panic.

thread fl2_worker_thread panicked: called Result […]

[Original post on mstdn.social]
November 19, 2025 at 3:02 AM
jschauma.mstdn.social.ap.brid.gy
I just wasted a good 20 minutes trying to remember and find that stupid Scumbag Steve meme pic, but I think you'll agree that was time well spent. #shitposting
They're the same picture meme: Top picture: two photos, one of Scumbag Steve, one of Sam Altman; caption "corporate needs you to find the differences between this picture and this picture" Bottom picture: Pam Beesly from The Office saying "they're the same picture"
November 14, 2025 at 7:10 PM
jschauma.mstdn.social.ap.brid.gy
"Always comment your code!"

...

🤦
// IP address to bind IP net.IP // Port to listen on Port int // Log output writer LogWriter io.Writer // Enable caching EnableCache bool // Cache storage location CacheLocation string
November 12, 2025 at 8:33 PM
jschauma.mstdn.social.ap.brid.gy
TIL: the Hoatzin

Contemporary flying dinosaur. Entirely folivorous, effectively a ruminant (complete with methane belches), shitty at flying, loud and stinky, and the chicks have claws like an archaeopteryx.

Birds, man. Bird is the word.
Photo of a hoatzin
October 31, 2025 at 3:30 PM
jschauma.mstdn.social.ap.brid.gy
Me when "hackers" ask for a reward for reporting a vulnerability of "weak SSH ciphers" on a hostname that resolves to 127.0.0.1.
Screengrab: Tommy Lee Jones from "No Country for Old Men" looking over his reading glasses, newspaper in hand.
October 29, 2025 at 1:54 PM
jschauma.mstdn.social.ap.brid.gy
Sage advice. (Steps 1-3 are optional, but highly recommended.)
How to avoid stress at work: 1. Start with your favorite coffee beans. 2. Brew. 3. Savor the first sip. 4. Don’t go to work.
October 27, 2025 at 5:43 PM
jschauma.mstdn.social.ap.brid.gy
Advanced Programming in the Unix Environment

Week 7: Signals

In this video lecture, we look at Unix signals, simple, asynchronous event notifications. We run through a number of examples to illustrate how signals are delivered, can be ignored, caught, handled […]

[Original post on mstdn.social]
A lecture slide entitled "Signals summarized" containing a drawing in demotivational poster style: one crudely drawn person stabs another with a sword. Underneath: "Shit happens. And most of the time it sucks."
October 27, 2025 at 1:23 PM
jschauma.mstdn.social.ap.brid.gy
Advanced Programming in the Unix Environment

Week 7: Job Control

In this video lecture, we illustrate the concept of job control in the shell, first introduced in the C shell, and allowing you to run multiple tasks from within the same terminal, switching back […]

[Original post on mstdn.social]
Job Control * both background and foreground process groups may report a change in status to the login shell • the foreground process group can perform I/O on the controlling terminal • the controlling terminal can generate signals via keyboard interrupts to send to the foreground process group • the background process group may be able to write to the controlling terminal • the background process group may generate a signal to send to the controlling terminal if it needs to perform I/O • the shell may move process groups into the foreground or background, suspend or continue them • we can send any signal to any process via kill(1)
October 26, 2025 at 3:22 PM
jschauma.mstdn.social.ap.brid.gy
Advanced Programming in the Unix Environment

Week 7: Process Groups and Sessions

Let's take a look at how processes are grouped together and begin to develop an understanding of how a login session relates to the controlling terminal.

https://youtu.be/NfHqGv0PlIw

#apue #Unix #Programming
October 25, 2025 at 4:00 PM
jschauma.mstdn.social.ap.brid.gy
Oh yeah, y’all know what time it is.

https://www.mcsweeneys.net/articles/its-decorative-gourd-season-motherfuckers
A farmer’s market table full of decorative gourds. Blammo!
October 24, 2025 at 6:21 PM
jschauma.mstdn.social.ap.brid.gy
Advanced Programming in the Unix Environment

Week 7: The Login Process

We'll begin our discussion of process relationships, including process groups, sessions, and our first, asynchronous type of inter process communication in the form of signals. To get us […]

[Original post on mstdn.social]
Diagram of relationships of the login process: init -> fork -> multiple inits each exec -> getty getty execs login login execs /bin/sh /bin/sh forks multiple times for each command, then execs each command
October 24, 2025 at 1:49 PM
jschauma.mstdn.social.ap.brid.gy
Congress already said they’re fine with Trump wantonly killing people (>32 so far); the military evidently won’t refuse any orders of this sort. At what point does the international community start to act?

https://www.nytimes.com/live/2025/10/22/us/trump-news
This was the eighth known strike that U.S. Special Operations forces have conducted since Sept. 2, when the military, on President Trump’s orders, began killing people aboard boats believed to be smuggling drugs as if they were enemy combatants in a war rather than criminal suspects. The administration has previously acknowledged seven strikes, which it said have killed 32 people. It has not yet announced the latest strike, which was earlier reported by CBS News.
October 22, 2025 at 5:48 PM
jschauma.mstdn.social.ap.brid.gy
Trump literally demolishing the White House may just be too much symbolism for me.
Picture of a construction crane of some sort demolishing part of the White House.
October 22, 2025 at 2:01 AM
jschauma.mstdn.social.ap.brid.gy
Huh, that's a new one. Fake Cloudflare captcha asking you to please run the osascript from http://185.93 . 89.62/d/xxx33312 to collect and uplaod all your passwords and cookies.
October 20, 2025 at 6:31 PM
jschauma.mstdn.social.ap.brid.gy
I’ve walked about 30 blocks so far and this is still going strong. #nyc dies not abide to bullshit. #nokings
October 18, 2025 at 5:36 PM
jschauma.mstdn.social.ap.brid.gy
Love the vibe of the inflatables. We stand with frog. #nokings #nyc
October 18, 2025 at 5:14 PM
jschauma.mstdn.social.ap.brid.gy
#nokings #fucktrump #fuckICE #nyc
October 18, 2025 at 5:04 PM
jschauma.mstdn.social.ap.brid.gy
Just about the only time I enjoy the crowd in Times Square. #nokings #nyc
October 18, 2025 at 4:53 PM
jschauma.mstdn.social.ap.brid.gy
#nokings #nyc
October 18, 2025 at 4:51 PM
jschauma.mstdn.social.ap.brid.gy
Advanced Programming in the Unix Environment

Week 6: Memory Layout of a Process

Let's talk about the details of a process. We start with a visual representation of a process in memory and create a program that prints out the addresses of different elements of […]

[Original post on mstdn.social]
October 17, 2025 at 12:28 PM
jschauma.mstdn.social.ap.brid.gy
Advanced Programming in the UNIX Environment

Week 4: Links

In this video lecture, we'll take a look at the system calls used to create, remove, and rename both hard- and symbolic links. We'll compare expected output against trivial implementations of the ln(1) […]

[Original post on mstdn.social]
Links -------- You now can implement ln(1), mv(1), and rm(1). The link count (st_nlink) keeps track of how many names for a file exist; if this count is 0 and no process has a file handle open for this file, the data blocks may be released. Renaming a file on the same filesystem is trivial, but renaming across filesystems and between files and directories requires a little bit more work. Symbolic links can link to any file regardless of type, existence, or filesystem / device location.
October 1, 2025 at 9:18 PM