ProgProj

[ppmemos]

How To – Linux find Windows 10 OEM product key

To find your original Windows 10 product key from Linux:

Open the terminal application.

You must run the Linux command as the root user.

Type ‘sudo strings /sys/firmware/acpi/tables/MSDM‘ to print Windows 10 or Windows 8 OEM product key

You can also use the acpidump command to get the same information under Linux.

[ppmemos]

22 Linux Networking Commands for Sysadmin

In this article, we will review some of the most used command-line tools and utilities for network management, troubleshooting and debugging in Linux.

[ppmemos]

Using uSD as JTAG connector

Espressif ESP32 also has a JTAG interface, but interestingly it’s shared with the SD card interface, and in ESP32 LyRaT audio development board where both MicroSD card slot and JTAG header are present selection is made by jumpers.

The extract from ESP32 LyRaT schematics above shows IO’s 12, 13, 14 and 15 can present on the SD card and 4-pin JTAG header. Some boards may not come with a JTAG header but may feature a MicroSD card slot, but you don’t have to solder wires to the board to access JTAG, and instead, you could simply use a custom MicroSD card adapter to insert into the MicroSD card socket of the board and access JTAG as explained by cibomahto on Twitter.

Nice little hardware trick! The photo below shows what it looks like when an ESP32 board is connected to a “JTAG debugger” (actually ESP32-Ethernet-Kit development board with FTDI chip). If your board comes with a full-sized SD card socket using a standard MicroSD to SD adapter should work too.

Reading comments on Twitter also informs use ESP32 is not the first platform with this trick, as (some?) Allwinner processors also route JTAG signals via the SD card interface.

[ppmemos]

tcpdump with grep

tcpdump -vvvs 1024 -l -A tcp port 80 | grep -E 'X-Forwarded-For:' --line-buffered | awk '{print $2}; fflush(stdout)' > file

[ppmemos]

How To Set Up and Configure an OpenVPN Server on Ubuntu 20.04 | DigitalOcean

OpenVPN is an open-source Virtual Private Network (VPN) application that lets you create and join a private network securely over the public Internet. In this tutorial you will learn how to install and configure OpenVPN on an Ubuntu 20.04 Focal server

[ppmemos]

Python3 binascii

import binascii coinbase = binascii.a2b_hex(template['coinbasetxn']['data']) extradata = b'my block' # The following can be done better in both Python 2 and Python 3, but this way works with both origLen = ord(coinbase[41:42]) newLen = origLen + len(extradata) coinbase = coinbase[0:41] + chr(newLen).encode('ascii') + coinbase[42:42 + origLen] + extradata + coinbase[42 + origLen:]

[ppmemos]

Is there a way to modulate my voice on the fly?

Install some necessary software:

sudo apt-get install sox libsox-fmt-pulse pavucontrol

Make a null-sink in pulseaudio:

pactl load-module module-null-sink

Start sox recording from the default recording device (default source) and outputing to the the null-sink:

sox -t pulseaudio default -t pulseaudio null pitch -800

(If you don't want to record from the default source, change the above command accordingly.) The -800 in the above command is the desired pitch change, you can modify that value as you want, e.g. -300, +200, +500, etc. . sox also have some other "effects" other than pitch changing which can be applied to the audio, you may want to check those out in man sox.

Start your capturing program (Skype, Teamspeak, etc.).

Start pavucontrol.

While you capturing program is trying to capture it will show up in pavucontrol under the Recording tab. Change its recording source from the default to Monitor of Null Output.

Notes:

You can make pulseaudio load the null-sink automatically, if you edit the /etc/pulse/default.pa file and add the following line to the end of that file:

load-module module-null-sink

The changes you make in pavucontrol will be remembered, so the next time you start you capturing program it will automatically try to record from the null-sink. If this is not OK for you, then just change back the source to the default in pavucontrol when you need.

If you prefer the terminal way: You can set the recording source for your capture program in the terminal (without using pavucontrol), if you launch your program with the PULSE_SOURCE variable set correctly. E.g. to launch skype recording from the monitor source of the null sink:

PULSE_SOURCE=null.monitor skype

Changing the pitch of your voice doesn't give you very good privacy:

If the other end knows you, knows you real voice, then you will have to alter the pitch a lot, so it will be obvious for the other end that you altered your sound. If he wants, he can capture your altered voice and change back the pitch. Or the other end may just ignore/reject your call for obvious reasons.

If the other end doesn't know your real voice, well... In this case there is no real benefit from altering your voice, since they don't even know the real one.

If you are trying to protect against someone intercepting your voice, a man-in-the-middle attack, etc. , then it is very likely that those malicious guys know quite enough to recover your real sound from almost any modification you do on it with such simple softwares.

Also, for all the above cases: When you speak, it is not just the sound of your voice what can identify you, but the way you speak, your accent, the words and phrases you use, etc.

If you want a more secure way for voice communication, you may want to use a text-to-speech engine to turn your typing into voice. That is a much more secure way. (Of course this might not be a possibility if it is not possible to type your messages, e.g. in a multiplayer game.)

Nevertheless, this method gives better privacy then no privacy at all. And it can be also fun to fool some friends with an altered voice.

[ppmemos]

Is there a way to modulate my voice on the fly?

I need a way to modulate my voice on-the-fly (to lower or raise pitch, etc, for privacy) for use in Mumble, TeamSpeak and other such programs. Is there any way to do this under Linux/Ubuntu? I have

[ppmemos]

Lans behind OpenVPN

here is an example of how to have multiple lans behind OpenVPN from ##OpenVPN on freenode.

[ppmemos]

Extend lvm volume

$ pvs  PV         VG        Fmt  Attr PSize    PFree  /dev/sdb1  ubuntu-vg lvm2 a--  <119.24g    0 $ vgextend ubuntu-vg /dev/sdc2 $ lvextend -l +28497 /dev/ubuntu-vg/root $ resize2fs /dev/ubuntu-vg/root

[ppmemos]

pass and gpg2 switch pinentry-program without GUI

sudo update-alternatives --config pinentry  Selection    Path                      Priority   Status ------------------------------------------------------------  0            /usr/bin/pinentry-gnome3   90        auto mode  1            /usr/bin/pinentry-curses   50        manual mode  2            /usr/bin/pinentry-gnome3   90        manual mode * 3            /usr/bin/pinentry-gtk-2    85        manual mode

[ppmemos]

Industrial Quality Control with the Raspberry Pi                      John Davis              the Rhubarb OpenPAC

[ppmemos]

TL;DR Awk crunches massive data; a High Performance Computing (HPC) script calls hundreds of Awk concurrently. Fast and scalable in-memory solution on a fat machine.

[ppmemos]

"Nick Strayer wrote about using AWK and R to parse 25 terabytes of data across multiple cores. Other big data examples are the tantalizingly-titled article by Adam Drake, "Command-line Tools can be 235x Faster than your Hadoop Cluster", and Brendan O'Connor's "Don’t MAWK AWK – the fastest and most elegant big data munging language!""

[ppmemos]

Linux Kernel /etc/sysctl.conf Security Hardening - nixCraft

Linux Kernel /etc/sysctl.conf Security Hardening - Learn about setting the Linux kernel settings to secure Linux networking stack and other part of system.

[nixcraft]

Want description of the Linux/BSD/macOS/Unix filesystem hierarchy?

Try the following command:

man hier

[nixcraft]

How to mount an ISO image/file under Linux - nixCraft

Mount an ISO file in Linux - Explains how to mount an ISO image file under any Linux distribution using loop devices and mount command on the CLI/GUI tools.