GNU Linux and Free, Open Source Software

Here is a list of most of the articles and Howto's I've written about Gnu Linux and other free, open source software. They include tutorials and introductory guides I've written for students, notes for myself so I don't forget stuff and things that I think may be useful for others. In many cases I gained the knowledge from reading and using other peoples blogs and web forum posts - so credit goes to all the original authors. Some of the Howto's below link to the same page (e.g. if the page addresses multiple topics), while a few link direct to my YouTube videos.

Linux: Ubuntu, command line utilities, Bash, servers, ...

• Deploying Your Own Server with DigitalOcean. Instructions from a workshop that had participants deploy a DigitalOcean droplet, setup Apache and MySQL, as well as Tor, PPTP and OpenVPN for privacy. Programs: , apt-get, usermod, mysqladmin, gpg, iptables. 31 Jul 2014
• Multimedia on Linux Command Line. Examples of various command line tools for audio/video processing, screencasting, file downloads and manipulating PDF documents. wget, evince, pdftk, cat, ffprobe, ffmpeg, flac, rec, faac, screencast. 23 Jul 2014
• Aliases, prompts and scripting on Linux command line. Demos of creating command aliases, modifying the shell prompt and beginning to write scripts in Linux. man, apropos, info, alias, source, bash. 23 Jul 2014
• Example of Setting Linux File Permissions. Gives a detailed example of setting permissions in Linux. Programs/Files: adduser, addgroup, ls, chmod, chown, /etc/passwd, /etc/shadow, /etc/group. 5 Jan 2014
• Ubuntu One on a Headless Server. Ubuntu One is Canonical's online file storage service. I setup Ubuntu One to work on a server that doesn't have a GUI. 23 Dec 2011
• Enabling Scroll with Microsoft Natural Ergonomic Keyboard 4000 in Ubuntu Linux. 19 Jul 2011

Virtualisation: VirtualBox, KVM, QEMU, virtnet, ...

• Virtual Networking with VirtualBox. The overview page for all my info about virtnet, which is a set of Bash scripts that I've created to simplify the process of setting up multiple Linux guests in VirtualBox. The guests form a virtual network and allow demonstration and testing of network and security applications. From this page you will find other articles about different tasks of using virtual networks. 19 Sep 2013
• Automatic backup of running KVM virtual machines. Use LVM snapshots and cron to backup a running KVM virtual machine image. Programs: lvm, tar, cron. 7 Jun 2012
• Increasing a KVM virtual machine disk. When running a Ubuntu Linux server is a KVM virtual machine, shows how to increase the disk size for the guest, including changing the partition and extending the LVM phyiscal and logical volumes. Programs: . 19 May 2012
• Running multiple Linux servers as KVM virtual machines. Detail steps to use QEMU/KVM in a Ubuntu Linux host to run multiple Linux guests as virtual machines. Include firewall rules for network address translation and how to setup console access. Programs: . 31 Jul 2011

Networking: iperf, tc, TCP, ...

• Capturing Wireless LAN Packets in Monitor Mode with iw. An update of my original iwconfig instructions for capturing wireless packets; this newer set uses iw. Programs: iw, iwconfig, tcpdump, rfkill. 9 Mar 2015
• Using Multicast on a LAN in Linux. Quick tests of multicast in a LAN using iperf and udpcast. With udpcast you can send files to multiple computers at once. Programs: iperf, udpcast, dd. 9 Mar 2015
• Multiple Instances of iperf in Linux. Includes a simple Bash script for starting multiple iperf instances to automate testing of multiple parallel UDP or TCP data transfers. Programs: iperf, pgrep, pkill. 3 Feb 2013
• Talking to Martians: Communications with Mars Curiosity Rover. 29 Aug 2012
• Flow Control Efficiency Calculator. 31 Aug 2012
• Impact of Bandwidth Delay Product on TCP Throughput. 11 Mar 2012
• Use iperf to measure network performance. A quick start guide showing the basic iperf commands. A video demo is also available with some more details, like both UDP and TCP tests. Programs: iperf, tc. 19 Jan 2011
• Dropping Packets in Ubuntu Linux using tc and iptables. 18 Jan 2011
• Capturing wireless LAN packets on Ubuntu. Shows how to use the command line in Ubuntu to put a wireless interface into monitor mode and then capture packets (including packets from other computers). Also includes steps for monitoring using Kismet. Programs: ifconfig, iwconfig, tcpdump, kismet. 29 Dec 2010
• Stream video across the Internet using VLC. Shows the command line parameters to start VLC as a streaming video server on one computer and then start the VLC client on another. Programs: < var class="cmd">vlc. 3 Jul 2010

Security: OpenSSL, DoS, web attacks, ...

• Testing HTTPS and Certificates with Apache, OpenSSL and tcpdump in a Virtual Network. Deploy a virtnet virtual network with VirtualBox, setup a fake website with Apache, and then install a certificate and test/capture HTTPS. Programs: VirtualBox, Apache, openssl, virtnet. 28 Apr 2015
• Using Classical Ciphers with pycipher. Install pycipher to get access to common classical ciphers such as Caesar and Playfair in Python. Programs: pycipher, python, apt-get, pip. 14 Dec 2014
• SQL Injection, CSRF, Cookie Stealing and Other Web Attacks in a Virtual Network. Use a virtnet virtual network to setup some fake PHP-based websites to demonstrate common web application security attacks, including SQL injection, Cross-Site Request Forgery and unvalidated redirects. Programs: mysql, apache2ctl, lynx, ssh, tcpdump. 23 Feb 2014
• Ping Flooding DoS Attack in a Virtual Network. Use a virtnet virtual network to demonstrate a denial of service attack with ping flooding. Programs: ping, tc, sysctl, iptraf, iptables, tcpdump, VBoxManage, apache2ctl, lynx. 21 Jan 2014
• Lecture on RSA Acoustic Cryptanalysis by Genkin, Shamir and Tomer. I gave a lecture to several students on the acoustic cryptanalysis attack on RSA, published by Genkin, Shamir and Tomer. You can view the screencast and download the slides. 27 Dec 2013
• Demo of Symmetric Key Encryption using OpenSSL. Examples of symmetric key encryption using a key and IV in OpenSSL. Programs/Files: openssl, xxd, /dev/urandom. 11 Nov 2013
• Address Spoofing with iptables in Linux. Shows how to use iptables to set a fake source address for IP datagrams sent by a Linux host. Includes a detailed example of using the fake source address to redirect pings. Programs: iptables, ping, tcpdump. 15 Sep 2013
• ARP Spoofing on a Wired LAN. Demonstrates using ettercap and apring to perform a man-in-the-middle attack on a wired LAN. Uses a virtnet virtual network. Programs: ettercap, arping, tcpdump, arp, ifconfig, sysctl, 4 Sep 2013
• Simple Introduction to using OpenSSL on Command Line. Examples of some common cryptographic operations - symmetric key encryption, random number generation, hashs, digital signatures, public key generation - using OpenSSL. Programs/Files: openssl, xxd, /dev/urandom, lsb_release, uname, diff, sed, sha256sum. 31 Jul 2013
• Passwords, Hashes and Rainbow Tables. A detailed write-up of how passwords are stored on computer systems, explaining the need for hashing the password and how using a salt effectively eliminates the ability to use rainbow tables to find a stored password. 14 Feb 2013
• Diffie Hellman Secret Key Exchange using OpenSSL. Demonstrates performing a secret key exchange using Diffie-Hellman with OpenSSL. Programs: openssl, cmp, xxd. 27 Jan 2013
• One Time Pad Example and Brute Force Attacks. 18 Nov 2012
• Classical Ciphers and Frequency Analysis Examples. 18 Nov 2012
• Public Key Encryption and Digital Signatures using OpenSSL. Demo of using OpenSSL to generate RSA public/private key pairs, then using them to encrypt, decrypt, sign and verify messages. Programs: openssl. 7 Apr 2012
• Upgrade to Latest Version of OpenSSL on Ubuntu. If your version of Ubuntu Linux is running an old (but working/secure) version of OpenSSL and you need a newer/latest version, this explains how to download, compile and setup the newer version. Programs: openssl. 7 Mar 2012
• Kismet on Lenovo IdeaPad V470. 29 Sep 2011
• Calculate SHA Hash of Linux Password in Shadow File. 8 Feb 2011
• Key Generation and Encryption Examples using OpenSSL. 22 Jan 2011

Multimedia: ffmpeg, VLC, ImageMagick, Audacity, sox, ...

• Live Webcam Streaming using VLC on the Command Line. Examples of using VLC to stream a webcam to other computers. Focusses on video streaming only (although also possible to include microphone audio). Programs: vlc, cvlc. 8 Mar 2015
• Converting Audio to Multiple Formats using ffmpeg or avconv. A Bash shell script I used to demonstrate to students batch conversion of WAV audio to formats such as MP#, AAC, Speex and others. Programs: ffmpeg, Bash. 28 Aug 2013
• Impact of Noise on Sine Wave Compared to Square Wave. 19 Jul 2012
• Using sox and Audacity to Demonstrate Communication Signals. 18 Jul 2012
• Streaming Audio and Video to Galaxy Tab 7.7 from Ubuntu. 2 Jun 2012
• Convert MKV to MP4 in Ubuntu. 2 Jun 2012
• Recording Lectures on Ubuntu using ffmpeg, sox and xdotool. 30 Jun 2011

Petri Nets: CPNTools, Lextools, FSM, ...

• Convert Coloured Petri Net State Space to Finite State Automata using CPNTools, FSM and Lextools. Gives a detailed example of a CPN, its state space, the ML code needed to write the state space to a text file, and how to use FSM/LexTools/GraphViz to obtain a minimised deterministic FSA. Programs: CPN Tools, FSM Library, LexTools, GraphViz. 20 Feb 2012

Document Editing: LaTeX, Emacs, Beamer, Subversion, ...

• LaTeX Class and Template for Quiz, Exam and Thesis at SIIT. Classes, styles and example LaTeX source for creating quizzes, exams and thesis at SIIT. Includes commands to allow creation of both question sheet and answer sheet from single LaTeX source file. 18 May 2014
• LaTeX Source Files for Lecture Notes on Internet and Security. Links to the LaTeX source, as well as PDFs, of many of my lecture notes, as well as other reports. 5 Dec 2013
• Email Notification of SVN Commits. If you are using Subversion (SVN) for file/document management, then this explains how to setup the Subversion server so that it will automatically send an email to selected recipients when someone commits to a SVN repository. 20 Feb 2013
• LaTeX, Subversion and Emacs. 12 Aug 2012
• My Collection of XFig Figures. 15 Jun 2012
• PhD Thesis LaTeX Source. 20 Feb 2012

Education: Moodle, QueXF, ...

• Presenting and Recording Lectures with Ubuntu Linux. Details my setup for recording lectures, including using the Wacom tablet, GIMP for drawings, and different workspaces. Programs: GIMP, xclock, bc, xsetwacom. 14 Dec 2014
• Printable PDF Math Exercises. A collection of math worksheets, primarily covering addition, subtraction, multiplication and division, that can be used for practice in primary school. 7 Sep 2014
• Using queXF in Ubuntu for Automatic Processing of Handwritten Questionnaires, Tests and Surveys. queXF and associated tools allow you to create a PDF suvery which is then printed and filled in by participants. Then the completed surveys are scanned and queXF processes them to extract the data. This article shows how to setup and use queXF in Ubuntu. Programs: wget, mysql, apache2ctl. 9 Sep 2013
• Upgrade to Moodle 2.5: Cannot Login as Guest. How to fix a problem caused when upgrading Moodle and using the old configuration settings (which cause you to not be able to login). Programs: Moodle, mysql. 4 Apr 2013
• Add Multiple Users to Moodle when using PAM Authentication. 26 Jun 2012

Created on Thu, 16 Jan 2014, 8:52pm

Last changed on Thu, 06 Nov 2014, 6:45pm