Agentless remote monitoring with SNMP and WMI

The previous article “Remote Monitoring System with Minimum Coding” presents an example how to monitor processes on Linux systems using simple bash script and upload result to the remote HTTP server. Linux cron service should schedule script execution on a repetitive basis. The bash script plays role of monitoring agent which collects required information and… Read More »

Raw sockets.

Approximately year ago I wrote an article “Wiresharking TCP Split Handshake Attack“. Normally client/server application written on socket level does not permit to split handshaking. For example TCP client connect function initiates a connection on a socket and performs all 3 handshaking step. Handshaking process is hidden in Transport layer of ISO model. To manipulate… Read More »

Question Mark Environment Variable in Linux

Question Mark Environment Variable is special variable in Linux and other Unix operating systems which contains status (return code) of shell commands or executable. This variable is widely used in scripts to verify exit status of shell command. The value range of question mark environment variable is between 0 and 255. Normally zero value means… Read More »

Decrypting TLS data with Wireshark on Mac

This post is about how decrypt TLS data with Wireshark using session key file. The session key file saves combination of secret keys which web browser used to encrypt or decrypt http traffic. Not all browsers may save session key, as I know only Google Chrome and Firefox permit to do this. The example below… Read More »

cURL without cacert or capath options

The curl as mention in its manual is the tool to transfer data from or to a server, using one of the different application-layer Internet protocol including HTTPS. With HTTPS curl works as CLI browser and supports TLS handshake process. cURL cacert option is used to specify certificate file to verify the peer, capath tells… Read More »

🍒 Cherry-pick in github

I began to use cherry picking to add changes from a commit from one branch and move them onto another branch. Cherry-pick looks promising for transferring the code changes between branches. Everything is simple according to the documentation but a little different in real life. It took me approximately one hour to pick a cherry… Read More »

Create private backup of your web site

Everything may happen, but being wise after the event sometime is not a good choice. On Saturday 28 August 2021 incident happened the data on servers of my Webhosting provider were wiped, some backups were destroyed also on many server machines. You can read more about this here . Most likely it was a Ransom… Read More »

Remote desktop from Mac to Windows and input control matching.

Recently working from home I needed to use remote desktop connection from Mac to Windows computer. Microsoft remote desktop client is available on the App Store. There was no problem with Microsoft Remote Desktop installation on Mac laptop and connection to Windows PC. The main difficulties appeared with using Mac keyboard with Windows applications. Later… Read More »

The GPG_TTY environment variable or github commit problem

I used a lot of different source control systems: SVN, CVS, Rational ClearCase, Perforce Helix, Bitbucket and others. Currently I am on github. Github looks indeed complex, even after Bitbucket which is based on git solution as well. Recently I cloned my repository on new Azure Linux virtual machine, everything was OK until commit step.… Read More »