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!

Lifecycle of Supervisors and Processes

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

This is a free sample from the Elixir Patterns book

An Ubuntu WiFi Secure Captive Portal

Improvements, suggestions & fixes are welcome!

Captive portals can be a pain. Here's an opinionated and no-doubt entirely imperfect guide to setting one up for a WiFi access point on Ubuntu (tested on 20+), utilising Network Manager, DNSMasq, HA Proxy and (optionally) Let's Encrypt for a secure, locally hosted landing page.

_Note: This setup was originally designed for an offline WLAN, providing access to a small number of locally hosted domains ... think the WiFi media portal on a flight or boat. If you are looking to provide internet access behind a captive portal then this guide won't get you all the way there. That said, many routers have this capability built in, as do any number of open source router firmware solutions. So you probably don't need to roll your own. If you'd like to try anyway, Ha Proxy Stick Tables would probably come in handy. Very happy to update the guide with any p

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.

Objective

Set default branch name for new repositories to "main"

git version 2.28+

$ git config --global init.defaultBranch main

git version 2.27 or less

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:

Python installation guide

These are my notes, not a generic solution. They are not meant to work anywhere outside my machines. Update version numbers to whatever are the current ones while you do this.

Install `asdf` and its python plugin, then install Python

asdf lives in https://github.com/asdf-vm/asdf

Follow its installation instructions, which at the moment of writing were:

	#
	# Compare Phoenix releases with additional custom setup to enhance comparison.
	#
	# Usage:
	# elixir <this_script_name.exs> 1.7.2
	# (downloads 1.7.2 and compares with the closest previously downloaded version if available)
	#
	# elixir <this_script_name.exs> 1.7.2 1.7.7
	# (downloads both versions and compares)
	#

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

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

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

	#!/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