Stefan Midjich stemid

Signing VirtualBox Kernel Modules

These are the steps I followed enable VirtualBox on my laptop without disabling UEFI Secure Boot. They're nearly identical to the process described on [Øyvind Stegard's blog][blog], save for a few key details. The images here are borrowed from the [Systemtap UEFI Secure Boot Wiki][systemtap].

Install the VirtualBox package (this might be different for your platform).

src='https://download.virtualbox.org/virtualbox/rpm/fedora/virtualbox.repo'

Install to Debian Buster
All of services needed to run Mastodon instance (tor, postgresql, redis, nginx) will be installed to the same server.

Install packages

# apt install postgresql redis nodejs npm ruby tor ffmpeg imagemagick git \
  nginx wget bundler protobuf-compiler iptables-persistent ncurses-term vim \
  gcc g++ make patch ruby-dev libprotobuf-dev libidn11-dev libpq-dev libicu-dev libxml2-dev libxslt1-dev

Dual GPG Yubikey Setup

If you follow this guide you will end up with an offline and online Yubikey. Use your online Yubikey for everyday life, signing/encryption etc. Offline key for signing keys for web-of-trust and replace lost online keys.

Awesome tools with PGP keys:

mozilla/sops dead-simple local encryption of sensitive files
popass.pw password manager for you and your team stored in git

Offline Yubikey

Hello software developers,

Please check your code to ensure you're not making one of the following mistakes related to cryptography.

I. General Mistakes

Writing your own home-grown cryptography primitives (For example: Mifare Classic)
- Exception: For the sake of learning, but don't deploy it in production.
Using a fast hash function (e.g. MD5, SHA256) for storing passwords. Use bcrypt instead.
Not using a cryptographically secure random number generator

	#!/usr/bin/env python

	import math
	import sys
	from moviepy.editor import AudioClip, VideoFileClip, concatenate_videoclips



	# Get average RGB of part of a frame. Frame is H * W * 3 (rgb)
	# Assumes x1 < x2, y1 < y2

	#include <time.h> // Robert Nystrom
	#include <stdio.h> // @munificentbob
	#include <stdlib.h> // for Ginny
	#define r return // 2008-2019
	#define l(a, b, c, d) for (i y=a;y\
	<b; y++) for (int x = c; x < d; x++)
	typedef int i;const i H=40;const i W
	=80;i m[40][80];i g(i x){r rand()%x;
	}void cave(i s){i w=g(10)+5;i h=g(6)
	+3;i t=g(W-w-2)+1;i u=g(H-h-2)+1;l(u

	#!/usr/bin/env python

	import tkinter as tk
	import math
	import re
	from collections import ChainMap

	Nrows = 5
	Ncols = 5

	" :[range]SortGroup[!] [n\|f\|o\|b\|x] /{pattern}/
	" e.g. :SortGroup /^header/
	" e.g. :SortGroup n /^header/
	" See :h :sort for details

	function! s:sort_by_header(bang, pat) range
	let pat = a:pat
	let opts = ""
	if pat =~ '^\s*[nfxbo]\s'
	let opts = matchstr(pat, '^\s*\zs[nfxbo]')

	import sys, marshal, functools, subprocess

	child_script = """
	import marshal, sys, types;
	fn, args, kwargs = marshal.load(sys.stdin)
	marshal.dump(
	types.FunctionType(fn, globals())(args, *kwargs),
	sys.stdout)
	"""

	#!/bin/bash

	gdb -p "$1" -batch -ex 'set {short}$rip = 0x050f' -ex 'set $rax=231' -ex 'set $rdi=0' -ex 'cont'