PAM Setup sudo apt install libpam0g-dev Compile gcc -fPIC -fno-stack-protector -c pam.c Add to dir with pam modules sudo ld -x --shared -o /lib/x86_64-linux-gnu/security/pam.so pam.o Update file /etc/pam.d/login # Standard Un*x authentication @include common-auth auth required pam.so