Shakiba Moshiri shakibamoshiri

Install FIO on Ubuntu/Debian:

sudo apt update
sudo apt install -y fio lshw

Install FIO on Fedora:

How to tunnel SSH over SSL/TLS

laptop ssh -> laptop stunnel -> evil network -> internet -> your server -> your server ssh

Server (your shell server/home box/work box/whatever)

Sets up a stunnel process listening externally on port 2443/tcp, forwards to localhost 22/tcp

Install stunnel, e.g. yum install stunnel
Install server config snippet to /etc/stunnel/stunnel.conf

OpenVPN and browser specific network routing with ip netns

Create network bridge

A network bridge allows us to have a virtual router that we can plug multiple network interfaces into. The IP address is assigned to the bridge rather than the individual network interface.

Create the bridge device, br0 :

ANSI Escape Sequences

Standard escape codes are prefixed with Escape:

Ctrl-Key: ^[
Octal: \033
Unicode: \u001b
Hexadecimal: \x1B
Decimal: 27

Wireguard and iptables restrictions for multiple users

If you don't know what Wireguard is, well, you should. It's fast, easy to setup and highly configurable. We will configure Wireguard for multiple users with various restrictions using iptables.

Assumptions

This should fit most setups (not mine though 😉)

	#!/bin/bash
	# A script to limit the outgoing bandwidth of the consensus and execution layers by port
	# We do this because the highest cost for running a node in AWS is the outgoing bandwidth

	# Define your ports and their corresponding rate limits
	declare -A ports=([30303]="500kbit" [9000]="1mbit")

	# Define arbitrary class IDs for each port
	declare -A class_ids=([30303]=1 [9000]=2)

	##TCP FLAGS##

	Unskilled Attackers Pester Real Security Folks
	==============================================
	TCPDUMP FLAGS
	Unskilled = URG = (Not Displayed in Flag Field, Displayed elsewhere)
	Attackers = ACK = (Not Displayed in Flag Field, Displayed elsewhere)
	Pester = PSH = [P] (Push Data)
	Real = RST = [R] (Reset Connection)
	Security = SYN = [S] (Start Connection)

	# https://www.percona.com/blog/2008/11/07/poor-mans-query-logging/

	tcpdump -i eth0 -s 0 -l -w - dst port 3306 \| strings \| perl -e '
	while(<>) { chomp; next if /^[^ ]+[ ]*$/;
	if(/^(SELECT\|UPDATE\|DELETE\|INSERT\|SET\|COMMIT\|ROLLBACK\|CREATE\|DROP\|ALTER)/i) {
	if (defined $q) { print "$q\n"; }
	$q=$_;
	} else {
	$_ =~ s/^[ \t]+//; $q.=" $_";
	}

	# install netctl
	sudo pacman -S netctl --noconfirm

	# check network card name
	ip link

	### Config Static IP Address ###
	# Card Name : eth0
	sudo cp /etc/netctl/examples/ethernet-static /etc/netctl/eth0

	#!/bin/bash

	## Create the response FIFO
	rm -f response
	mkfifo response

	function handle_GET_home() {
	RESPONSE=$(cat home.html \| \
	sed "s/{{$COOKIE_NAME}}/$COOKIE_VALUE/")
	}