mark254's comments

On: A novel channel contention mechanism for improving...

[mark254]

Sounds like Token Ring...

On: F3 – Fight Flash Fraud

[mark254]

Well, with the remaining trust available at this point you might just as well use something cryptographically secure, like encrypted ones, twos, or simple HMACs of the block number.

A too-simple scheme is likely to be detected (and bypassed!) by the firmware a nearly no time.

[jasomill → mark254]

Simpler: fill the drive with random data, hashing as you go, flush the kernel's buffer cache, hash the entire contents of the drive, and compare.

Conceptually,

  # tee /dev/DEVICE </dev/random | sha256sum
  # echo 1 > /proc/sys/vm/drop_caches
  # sha256sum /dev/DEVICE

though I wouldn't expect this exact command sequence to work unless tee's buffer size divides /dev/DEVICE's capacity and tee errors out writing past the end of /dev/DEVICE before writing to stdout.

[blibble → jasomill]

I did exactly this earlier last week

the drive size divided by 4MB, so dd with bs=4M and fixed count

(with oflag=direct you don't even need to drop caches)

[justinclift → jasomill]

Oh, that's a clever way of doing things.

The "write the block #'s to the given block" would help identify where a fraudulent device goes wrong.

But for just checking if a device is storing data 100% correctly then your way would probably be more robust. :)

[justinclift → mark254]

Sure, that's a decent idea too. :)

On: Zwentendorf Nuclear Power Plant: Finished in 1978 ...

[mark254]

HackFu 2021 was held there: https://hackfu.at/

On: Would you use a government-issued ID to prove your...

[mark254]

This is already possible in Austria.

The "eAusweise" app allows people to "prove" others their age without giving away any more data:

https://www.digitalaustria.gv.at/eng/services/eServices/Proo... (German only:) https://www.oesterreich.gv.at/eausweise/haeufige-fragen/haeu...

On: It's 2023, so of course I'm learning Common Lisp

[mark254]

I often use RHEL7-compatible binaries on RHEL8 and Debian (testing) machines, with no problems.

On: Velocity defeats itself – get acceleration instead

[mark254]

Wouldn't a (3-D) cube have eight corners?

And 3 length dimensions plus time gives a hypercube, with 16 corners.

For 11 dimensions, 2048 corners... for 26, 2^26 ;)

[mathgeek → mark254]

Good discussion on this at https://old.reddit.com/r/askmath/comments/10a2xmc/do_corners...

One of the requirements is that you have to clearly define whether your n-dimensional object is a solid.

[inkcapmushroom → mark254]

You should instead try some belly-button logic.

On: An X11 apologist tries Wayland

[mark254]

> By the way, does anyone know of a VNC-like solution that can use MPEG compression?

You want xpra.

On: RDP Clients for Debian: An incomplete review

[mark254]

Try http://xpra.org/ - that's a "gnu screen" for X11, but bandwidth-optimized, can also relay USB, audio, ...

Just to give you an idea: I used it for forwarding a Firefox window across an UMTS connection when sitting in a train. (Long story: 32bit Java required to remote desktop into a client's environment across the Atlantic, ugh.)

[BLKNSLVR → mark254]

I have tried xpra, and it was my go-to option until I tried NoMachine. I did try just forwarding windows, Firefox it was too, but there was some(times) frustrating delays.

I may re-visit, however, as the delays could have been network/environment issues rather than the technology.

On: Lighthouse Map

[mark254]

Even some on the Danube - in the middle of Europe...

On: Don't start with microservices – monoliths are you...

[mark254]

Well, a simple solution is to only have one middleware that uses database connections, and have all other things around it be purely functional. (Though that may mean using their own databases, of course).

[Philip-J-Fry → mark254]

What do you mean by that? What if I have 2 services, each with their own databases, but the action is supposed to be atomic. E.g. there's a foreign key that links the data.

They're both gonna do their own database functions.