Lech Perczak Leo-PL

The purpose of this document is to get you familiar with the concepts and command line tools involved with connecting to the internet using modern 4G LTE modems on both Debian/Ubuntu and OpenWRT.

This writeup is based on my experiences with the Sierra Wireless AirPrime MC7455 modem and a Calyx (Sprint) SIM card, but it should apply to most modern 4G LTE modems.

High level overview

These are the steps required:

Physically connect antennas

1. Install tools and config IPXE

# Install compiler and dependencies
sudo apt-get install -y git gcc make liblzma-dev

# Grab the source code
git clone https://github.com/ipxe/ipxe.git
cd ipxe/src

# Enable NFS support

Keepass file format explained

I’m currently working (I’m just at the beginning, and I’m quite slow) on a personal project that will use Keepass files (kdb and kdbx).
I tried to find some documentation about .kdb and .kdbx format, but I didn’t find anything, even in the Keepass official website. I you want to know how these file formats are structured, you must read Keepass’s source code. So I wrote this article that explains how Keepass file format are structured, maybe it will help someone.

	#!/bin/bash

	function wait_for_host() {
	local host=${1}
	local port=${2}
	local count=${3}
	local tries=0
	TIMEOUT_SEC=1

	while (( ${tries} < ${count} )); do

	#!/usr/bin/python3

	# script created for reading SMS messages from 3G modem connected to PC
	# 1) it looks for modem
	# 2) reads all SMS messages from modem
	# 3) prints all found SMS messages to stdout only if total messages count
	# greater than SMS_STORE_COUNT (default is 3)
	# 4) save all but SMS_STORE_COUNT messages to txt files and
	# delete them from modem

	# All possible descrypt hashes of the password 'admin', using all possible salts.
	# From https://github.com/roycewilliams/kens-salty-rainbow
	# If you find a device that always uses one of these, let me know.
	..xpoEyRReGzk
	./nlIXYriZaB2
	.08iPeaCLti3E
	.1fH80ykoJAyI
	.23PstrXfk7Nw
	.37vRhjo4ZP66
	.4nTonCOGSWyU

	#!/bin/bash
	USER=""
	SERVER_HOST=""
	SERVER_PORT="22"
	REMOTE_PORT="22"
	LOCAL_PORT="1234"

	IDENTITY=$(mktemp)
	KNOWN_HOSTS=$(mktemp)

	#!/bin/sh
	USB_GPIO=21
	DELAY=1

	gpio_value="/sys/class/gpio/gpio${USB_GPIO}/value"
	echo 0 > ${gpio_value}
	sleep ${DELAY}
	echo 1 > ${gpio_value}

	#!/bin/bash
	DATE=`date -Idate`
	USER="root"
	HOSTS=("<host1>" ... "<hostn>")

	commit_single_host_to_git ()
	{
	local host=${1}

	local backup_filename="backup-${host}-${DATE}.tar.gz"