Checking Debian Linux user password without logging into system

Checking Debian Linux user password without logging into system

Problem

Imagine situation when you need to check a user's password without logging into system and any traces of action. I had this situation when I was able:

1. can execute sudo command;
2. I needed to check password of root user from my machine. Also, I was not interested of  password change for root user.

 Note: you can check password for any user of your system.

Building Python 3.6 on Raspberry Pi 3 from sources (clean Debian)

Building Python 3.6 on Raspberry Pi 3 from sources (clean Debian)

 

1. Problem

By default clean Debian installation contains Python version 2.7.9 on my Debian (Raspbian GNU/Linux 8 (jessie)"). But we want more! We need Python 3.X, this tutorial shows you how to install Python version 3.6.0 .

Warning! Newer versions of Debian for Raspbery Pi have SSH disabled, so you need enable it by creating empty file with name ssh (Yes, just three letters. Yes, without extension) in /boot section of SD-card. This section also visible under Windows, so you will have no problems to do this.

Note: This is updated version of my previous tutorial Building Python 3.5 on Raspberry Pi 2 (Raspbian) which fixes issues with TLS/SSL support of compiled Python.

ACT LED Heartbeat for Raspberry Pi

All models of Raspberry Pi have ACT led. ACT led ON when SD card in use and OFF otherwise. 

Except of Raspberry Pi Zero, this devices uses opposite rules - ACT led is always ON and OFF only when SD card in use. This is useful because Raspberry Pi do not have PWD led and you can't understand is it powered on or not.

I like to tune ACT led to be in heartbeat mode, in this mode ACT led blinks twice than pause and again. This is useful because you can understand that device not just powered but also Linux kernel active. 

All that you need just add one line to config.txt file located in /boot partition of SD card.

Note: /boot partition have FAT fs, so you can do all operations directly from Windows OS just by editing text file.

From Linux (Raspbian for example) you need execute
$ sudo nano /boot/config.txt

Then navigate to the end of file and add line:

dtparam=act_led_trigger=heartbeat

That's all. After reboot your ACT led will act in heartbeat mode.

Enjoy!

Raspberry Pi Zero USB dongle (use SSH over USB cable like over Ethernet)

Raspberry Pi Zero USB dongle (use SSH over USB cable like over Ethernet)

About post

Imagine, if you will be able to use SSH (or even VNC) connection to your Raspberry Pi Zero using only USB cable without any hardware modifications. Amazing, isn't it?

You can find other instructions on Youtube requires hardware modification, but you can do this without soldering and so on.

All you need to follow these instructions.

Connecting to your Raspberry Pi without monitor, keyboard and mouse. Quick start.

Connecting to your Raspberry Pi without monitor, keyboard and mouse. Quick start.

 About article

Imagine if you want your own Linux server for debugging and testing purpose. Of course you can buy VPS, but this is can be a little bit expensive for some cases. In this case you can use just Raspberry Pi which able to run Apache, Nginx, PostgreSQL.

So you need your RPi + PSU (Power Supply Unit) and RTC (preferred). 

But you need to configure your RPi, so you need keyboard, monitor, mouse, HDMI adapters and so on. Right? Wrong! Your do not need anything except RPi + PSU + RTC (optional).

Qt wrappers for codec2 library

Qt wrappers for codec2 library

About

As I wrote in previous post I was amazed by codec2 (w:codec2) library for speech encoding. You can find more documentation about how to build codec2 library on Windows in my previous post:

Building codec2 for Windows using Cmake and MinGW

You can find more information about codec2 on home page of codec2 here:

http://www.rowetel.com/?page_id=452

Next I want to write wrappers for Qt and test this library with my speech.  See below and you will find more.

Building codec2 for Windows using Cmake and MinGW

Building codec2 for Windows using Cmake and MinGW

I want to build and use codec2 library in my Qt application for Windows. Codec2 is incredible library for speech processing it can encode speech from 3200 up to 700 bit/s. Amazing! Let's play with it!

So I need to do:

1. build codec2 for Windows
2. write Qt wrappers for codec2 library;
3. write application able to use codec2 with QAudio sub-system. 

This post will explain how to do first step - build codec2 for windows using CMake and MinGW

Raspberry Pi (Raspbian): installing VeraCrypt from binaries. Tutorial

Raspberry Pi (Raspbian): installing VeraCrypt from binaries. Tutorial

As you know TrueCrypt is't supported now. You can easily replace it with VeraCrypt, which can be found here.

Here you can find tutorial how you can install this software to your RPi and how to use it.

IMEI processing in Python

IMEI processing in Python

Today I used one of our systems (made by our command) and entered new device configuration. Our system blocked my input and said me that my input is incorrect.

I was surprised because I forgot about these checking. Then I remembered that few time I made class for IMEI processing.

I hope that it can be useful for someone else. So, you can use in your projects.

9-bit serial communication in Linux (Raspbian) 8M1, 8S1 modes (with sources)

9-bit serial communication in Linux (Raspbian) 8M1, 8S1 modes (with sources)

 Problem

As you know, there is a problem when you use 9-bit serial communication under Linux. Here you can find solution which will help you solve this issue.