I want to include the following PIN feature which can be used for authentication in Ubuntu 17.10 (both in a terminal session and during the login screen). Once an authentication string is entered, Ubuntu will check to see if it is "equal" to the encrypted password or to the encrypted PIN. It will authenticate. If not, the system will suspend the PIN feature until a successful authentication event has happened.
- Can I write a script that has access to entered authentication strings, at least during the login screen?
- Can I modify the existing Ubuntu scripts? If so, which ones?
- Can I use the underlying password encryption mechanism for my PIN? If not, how can I get started on writing an encryption algorithm to store and recover PINs and passwords?