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maxvt / hp-p1109w-on-ubuntu-1604.md
Last active February 22, 2019 22:48
Solution for a HP LaserJet P1109w not printing on Ubuntu 16.04 Xenial Xerus

As usual, Linux needs a bit of under-the-hood wrenching to get things working. HP is actually doing Linux support commendably compared to its peers (see hplip). However, in this case a bit of extra grease was needed.

Symptoms: Printer is detected automatically. A test page fails to print. CUPS logs say:

hp[14727]: io/hpmud/musb.c 2095: Invalid usb_open: Permission denied

Solution: Note that this will potentially mess up any HP scanners you have installed. If the P1109 is your only HP device, no problem. I do not claim this to be the correct, the most appropriate, or the

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maxvt / scala-and-elixir-sf-meetup-notes.md
Created June 10, 2016 21:06
Notes on _Scala and Elixir_ - a talk by Jeff Alexander at Erlang&Elixir SF MeetUp (8-Jun-2016)

Notes on Scala and Elixir - a talk by Jeff Alexander at Erlang&Elixir SF MeetUp (8-Jun-2016)

Jeff uses mostly Scala at work, trying out Elixir mostly for personal education.

Both languages are VM based. Scala: everything is a function. Elixir: everything is an expression. Both have tail recursion and pattern matching.

Let's look at performance:

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maxvt / infra-secret-management-overview.md
Last active November 1, 2024 21:34
Infrastructure Secret Management Software Overview

Currently, there is an explosion of tools that aim to manage secrets for automated, cloud native infrastructure management. Daniel Somerfield did some work classifying the various approaches, but (as far as I know) no one has made a recent effort to summarize the various tools.

This is an attempt to give a quick overview of what can be found out there. The list is alphabetical. There will be tools that are missing, and some of the facts might be wrong--I welcome your corrections. For the purpose, I can be reached via @maxvt on Twitter, or just leave me a comment here.

There is a companion feature matrix of various tools. Comments are welcome in the same manner.

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maxvt / writeup-ictf15-temperature.md
Last active August 29, 2015 14:19
UCSB iCTF 2014-2015 writeup - service "temperature"

This is a warmup-level challenge written in Python. The service opens a TCP socket on port 56098 and listens for commands to store or read a temperature reading based on time and location. The data is stored into a single flat file.

Simply interacting with the service over telnet would not work, as the service only attempts to read once and telnet sends a packet per character. The protocol is very easy to reconstruct by reading the source, though, and writing a small client to store and load data takes all of two minutes.

This service was one of the first ones being exploited by many teams.

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maxvt / keybase.md
Created April 4, 2015 02:18
Keybase proof

Keybase proof

I hereby claim:

  • I am maxvt on github.
  • I am maxvt (https://keybase.io/maxvt) on keybase.
  • I have a public key whose fingerprint is DF96 1F5F 85D9 F81C E581 5DA9 B243 60C4 D7E6 ED09

To claim this, I am signing this object:

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maxvt / generate_web_server_certificate.md
Last active August 29, 2015 14:12

How to generate a web server certificate for signing with StartSSL

The authoritative version of this gist will be maintained at http://www.maxvt.net/2014/12/23/web-certificate-startssl.html

A lot of advice on the web is outdated. There are three critical points that might be out of date or wrong:

  • Use 2048 bit key length. 1024 bit length is no longer considered secure, but if your server software is old enough, it might still be the default setting.
  • Use SHA-256 hash. The default is the older SHA1, which is being phased out since it is considered less secure. Apparently, by choosing SHA-256, you will lose compatibility with Windows XP and Windows Server 2003. Hopefully you do not run those anymore and therefore don't care.
  • Create a CSR (certificate signing request), not a self-signed certificate. A lot of advice on self-signed certificates was written when SSL certs were e
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maxvt / apple_tax.md
Last active August 29, 2015 14:09
Apple Tax 2015

This table compares the current compact (13") Retina MacBook Pro to potential alternatives. The current price premium for buying Apple as compared to similarly configured other brands is only 2-6%, compared with 40% in my 2010 calculation.

Discussion follows below. Send in your comments, fixes, and updates--I only do research like this when I'm personally interested, which is about once every few years when I need to update my hardware, but I don't mind quickly integrating fixes for the benefit of all.

Maker, Model CPU RAM Ram tech Display SSD USB Eth Size Wt W Sticker Best Notes
Apple, rMBP 2.8 i5 16 DDR3L 1600 2650x1600, 13" 512 2 No 12.4x8.7x0.7 3.5 3 2248 2062 Education discount
Apple, rMBP 2.8 i5 16 DDR3L 1600 2650x1600, 13