python3 -m venv .venv
source .venv/bin/activate
pip3 install -r requirements.txt
clang-format -i pam_2fa.c
Compile client.py using
pyinstaller -F client.py
Run the client binary and enter your registration details
Once your phone numbered is entered, you will receive a code to confirm your registration to your phone number
Once you confirm the registration a file located in your home directory will be created under $HOME/.2fa
Compile the PAM module using the build script build.sh or put the pre-compiled binary into /lib/security
Now edit the /etc/pam.d/common-auth configuration and add a line after the last auth required module that you can see and write
auth required pam_2fa.so
Editing the common-auth configuration will make it ask for a 2fa code every time any authentication is required, if you would like to do this only in specific scenarios, you should add this auth required line in the appropriate configuration
Most common scenario would be to add it in /etc/pam.d/gdm-password
If you are using Ubuntu, this would make it that 2fa is only required on login via the Gnome Display Manager
Once that is done, try to login and observe the required 2fa code for authentication
Log into a root user as the GSM module requires elevated permissions to access the physical GSM device
Activate the virtual environment as root
Launch the api python3 run.py main