PINs or passwords for users

[sde1000]

Some sites have an issue with till users just grabbing a wristband or other NFC token and using it, not caring whether it is their own.

We could enable users to set a PIN or password, which the till could check in some circumstances. The best compromise between usability and security that I can think of is to check the PIN or password if the usertoken being used has not been seen for some time. (So, someone ["A"] working and regularly tapping in will not be asked for their PIN; if someone else ["B"] picks up another wristband that is also assigned to "A" and tries to use it, they will be asked for "A"'s PIN.)

Schema changes:

• Add a password column to User
• Add a "last successful login" column to UserToken, to be updated whenever the token is successfully used to access the till (whether the password was requested or not)

Configuration options:

• Do we require users to set a PIN or password if they do not currently have one?
• Should users be asked for their PIN or password?
• How long can a usertoken go without being used successfully before the password is requested again?

We could possibly combine the last two into a single config item; no checks if blank, otherwise it's a length of time.