Dmitriy Pertsev pertsevds

Native Secure Enclave backed ssh keys on MacOS

It turns out that MacOS Tahoe can generate and use secure-enclave backed SSH keys! This replaces projects like https://github.com/maxgoedjen/secretive

There is a shared library /usr/lib/ssh-keychain.dylib that traditionally has been used to add smartcard support to ssh by implementing PKCS11Provider interface. However since recently it also implements SecurityKeyProivder which supports loading keys directly from the secure enclave! SecurityKeyProvider is what is normally used to talk to FIDO2 devices (e.g. libfido2 can be used to talk to your Yubikey). However you can now use it to talk to your Secure Enclave instead!

Some hosting providers like scaleway allows to remove the IPv4 from the VPS in order to save 1€/month but doing this will result in losing connectivity to the "IPv4 world".
Or you may have ordered a VPS that only has IPv6 connectivity and you want to access to a resource only accessible from the "IPv4 world".
Here is how to gain your access back to the "IPv4 world".

Change your name servers(s) to DNS64 name servers(s)

Note: You may deploy your own DNS64 & NAT64 server on a separate server by following this tutorial (untested): https://packetpushers.net/nat64-setup-using-tayga/.
Note²: You may find a explanation of what is NAT64 and DNS64 on Wikipedia.

Choose a/multiple DNS64 public server(s) that has/have its own NAT64 public service from this list:

Lifecycle of Supervisors and Processes

Mix.install([
  {:kino, "~> 0.6.2"}
])

This is a free sample from the Elixir Patterns book

Hydrate ETS from DETS using an init GenServer

Mix.install([
  {:kino, "~> 0.6.2"},
  {:telemetry, "~> 1.2.1"}
])

This is a free sample from the Elixir Patterns book

Intro

This note describes how to connect two networks/devices/VMs over public network using Wireguard with Layer 2 support (ARP, IPv6 link-local, etc).

This can also be achieved using SSH and its "tap" tunnel, however, it does not provide the same level of latency and bandwidth as full-blown VPN such as Wireguard.

In addition, this note describes how to tunnel Wireguard over TCP connection. This may be of use if you encounter firewall in-between so, for instance, you can use TCP port 443 only.

	# /etc/udev/rules.d/99-usb-serial.rules
	# udevadm info --attribute-walk -n /dev/ttyUSB0 \|grep serial (can be used to get serial number)
	# udevadm control --reload-rules (reload rules)
	# udevadm trigger (re-add all devices)
	# see https://wiki.archlinux.org/index.php/Bus_pirate
	# for some reason, ATTRS{bInterfaceNumber}=="00" is not working, hence the use of ENV{}

	# single USB/serial adapters
	SUBSYSTEM=="tty", ATTRS{serial}=="A900TUKZ", SYMLINK+="ttyUSB_bub_1"
	SUBSYSTEM=="tty", ATTRS{serial}=="A700fdWb", SYMLINK+="ttyUSB_bub_2"

	{
	description = "A nixos cloudinit base image without nixos-infect";

	inputs = {
	nixpkgs.url = "github:nixos/nixpkgs";
	};

	outputs = { self, nixpkgs }:
	let
	system = "x86_64-linux";

	f().

	Str = fun(X) -> io_lib:format("~p", [X]) end.

	Percent = fun
	(A, 0) -> "100%";
	(A, B) -> [Str(round(100*A/B)), "%"]
	end.

	Get = fun

	#!/usr/bin/env bash
	#Install brew and qemu + cloud init metadata dependencies
	/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
	brew install qemu
	brew install cdrtools

	rm -rf /tmp/ubuntuqemuboot

	#download Ubuntu 20.04 Cloud Image and resize to 30 Gigs
	mkdir -p /tmp/ubuntuqemuboot/images

	#
	# Usage:
	# elixir <this_script_name.exs> 1.7.2
	#
	# The script grabs a Phoenix version and places it
	# under `phoenix/<version>` subfolder. It attempts to call
	# a diff GUI, if there's another version found in `phoenix`.
	# It picks the closest older version, if more than one found.
	#
	# Feel free to modify PhoenixCompareConfig

Dmitriy Pertsev pertsevds

Native Secure Enclave backed ssh keys on MacOS

Change your name servers(s) to DNS64 name servers(s)

Lifecycle of Supervisors and Processes

This is a free sample from the Elixir Patterns book

Hydrate ETS from DETS using an init GenServer

This is a free sample from the Elixir Patterns book

Intro

Objective