olbat

Crypto Notes Week 1

The first half of the course will be about sym. enc. and the second half will be about public key enc.

Introduction and Prereqs

What is cryptography?

The core of cryptography is about:

• establishing a secret key between two parties

olbat

// https://developers.cloudflare.com/workers/about/ 
// https://tutorial.cloudflareworkers.com
//
// A Service Worker which adds Security Headers.
// Checks:
//     https://securityheaders.io/
//     https://observatory.mozilla.org/
//     https://csp-evaluator.withgoogle.com/
//     https://hstspreload.org/
//     https://www.ssllabs.com/ssltest/

olbat

#!/bin/bash
set -euo pipefail

BLOCKLIST_URL='https://list.iblocklist.com/?list=bt_level1&fileformat=p2p&archiveformat=gz'
BLOCKLIST_FILE=/var/packages/DownloadStation/etc/download/blocklists/level1

echo "Clean old blocklist"
rm -f $(dirname $BLOCKLIST_FILE)/*

echo "Download new blocklist"

olbat

Create SSH tunnels using systemd units

Table of contents

• Overview
• Setup the SSH agent systemd unit
• Setup the SSH-tunnel systemd unit
• Create tunnels using systemd services
• Examples
• Create a tunnel to a web server on a machine that's only accessible by SSH