Gabriel Moura gabrielmoura

tmux cheat sheet

(C-x means ctrl+x, M-x means alt+x)

Prefix key

The default prefix is C-b. If you (or your muscle memory) prefer C-a, you need to add this to ~/.tmux.conf:

remap prefix to Control + a

How to mount a qcow2 disk image

This is a quick guide to mounting a qcow2 disk images on your host server. This is useful to reset passwords, edit files, or recover something without the virtual machine running.

Step 1 - Enable NBD on the Host

modprobe nbd max_part=8

If you're not familiar: What is fail2ban? fail2ban is an awesome linux service/monitor that scans log files (e.g. auth.log for SSH) for potentially malicious behavior. Once fail2ban is tripped it will ban users for a specified duration by adding rules to Iptables. If you're unfamiliar with fail2ban Chris Fidao has a wonderful (& free!) series about security including setting up fail2ban here.

Recently Laravel released a new feature in 5.1 to throttle authentication attempts by simply adding a trait to your authentication controller. The Laravel throttle trait uses the inputted username, and IP address to throttle attempts. I love seeing this added to a framework out of the box, but what about some of our other apps not built on Laravel? Like a WordPress login? Or even an open API etc.? Ultimately,

Exporting your 2FA tokens from Authy to transfer them into another 2FA application

IMPORTANT - Update regarding deprecation of Authy desktop apps

Past August 2024, Authy stopped supported the desktop version of their apps:
See Authy is shutting down its desktop app | The 2FA app Authy will only be available on Android and iOS starting in August for details.

And indeed, after a while, Authy changed something in their backend which now prevents the old desktop app from logging in. If you are already logged in, then you are in luck, and you can follow the instructions below to export your tokens.

If you are not logged in anymore, but can find a backup of the necessary files, then restore those files, and re-install Authy 2.2.3 following the instructions below, and it should work as expected.

Arch Linux ARM 64 on Raspberry Pi 3 B+ With Full Disk Encryption And SSH Unlock: 2018 Edition

There are multiple ways to get a full disk encrypted arch linux system on raspberry. In this tutorial, we will install a 64-bit arch linux armv8 system, using dropbear as ssh server for remote pre-boot unlocking of the root filesystem. However, it will still be possible to unlock and use the pi as usual, with a keyboard and monitor. We will also create an unencrypted partition in the installation process, usable as a rescue system.

Differences to the 32-bit arch linux arm version:

probably better performance
can run 64-bit software
comes without the proprietary video-driver blobs

	/**
	* Método para gerar CNPJ válido, com máscara ou não
	* @example cnpjRandom(0)
	* para retornar CNPJ sem máscar
	* @param int $mascara
	* @return string
	*/
	public static function cnpjRandom($mascara = "1") {
	$n1 = rand(0, 9);
	$n2 = rand(0, 9);

	var keyhex = "8479768f48481eeb9c8304ce0a58481eeb9c8304ce0a5e3cb5e3cb58479768f4"; //length 32

	var blockSize = 16;

	function encryptAES(input) {
	try {
	var iv = require('crypto').randomBytes(16);
	//console.info('iv',iv);
	var data = new Buffer(input).toString('binary');
	//console.info('data',data);

	# jan/29/2018 22: 4:17 by RouterOS 6.41
	#
	/interface list
	add name=public comment="public network"
	add name=local comment="local network"
	add name=guest comment="guest network"

	# Change the interfaces below to your own
	/interface list member
	add list=public interface=ether1

	pkgname=duolingo
	pkgver=0.3.1
	pkgrel=1
	pkgdesc="Unofficial release of Duolingo for Linux / Learn languages by playing a game. It's 100% free, fun, and scientifically proven to work."
	url="https://www.duolingo.com/"
	arch=('x86_64')
	license=('custom')
	install=duolingo.install
	source=("https://github.com/mikethedj4/duolingo-linux/raw/master/${pkgname}-linux.tar.gz"
	"duolingo.desktop")


	#user nobody;
	worker_processes 4;

	#error_log logs/error.log;
	#error_log logs/error.log notice;
	#error_log logs/error.log info;

	#pid logs/nginx.pid;