This is a simple setup guide to enabling Two Factor Authentication (2FA) on Linux SSH login. I this article I wont go deep into setup and issues that I have faced when implementing this. First thing is first Update your system first. I have used Ubuntu 20.04 and it is always up to date. To enable 2FA you need to install google authenticator modules sudo apt install libpam-google-authenticator Configuration for PAM and SSHD Add the the following line to /etc/pam.d/sshd and After adding this line please restart the sshd services. auth required pam_google_authenticator.so Go to /etc/ssh/sshd_config and check if the following line exist. Default value will be "no" so change it to "yes" to activate. ChallengeResponseAuthentication yes Configuration for Authenticator In the terminal run google authenticator command It will ask few things to acknowledge by user. Details you can see from the below video. Once this part is done you are ready to use the 2FA in ubuntu. T...
Long time back i have posted on regarding a voltmeter. I know it took long time to complete it. But this completion is quit modified from my older design. I used an PIC16F88 which has 7 ADC channels .Keke i used only one at the moment. But have many thoughts for an upgrade sometime later. Everyone will think how this fella works. How it works? The circuit was design for two different parts. One is Analog side and other one is Digital side. Analog side does all the voltage conversion part for the micro controller. This was done by an LM358 which is an Operational amplifier, otherwise known as Op-Amp. Huge value of voltage will damage the micro controller. The input voltage for Micro controller should not exceed 5V so this part is handle by the analog circuit. Next is digital part which is the micro controller part which does all computing and display the result. This circuit is complicated for a newbie cause i used shift registers to handle the 7 segment displays. Micro controller outpu...