Comment 8 for bug 1347010

EntryIsLocked is only updated when the screen is turned off. So if you update your password type, it won't notice until you lock the screen. A bug, but not one that has affected anyone yet.

Thinking about what you'll need to implement this, it's probably better for you to query AccountsService's PasswordMode property for the current user -- if it is 2, they are in swipe mode, 0 for having set a password of some sort. And also the PasswordDisplayHint property on the com.ubuntu.AccountsService.SecurityPrivacy interface for the current user in AccountsService -- this will tell you whether it's a passcode (1) or passphrase (0).

Then you'd need to use PAM to actually authenticate.

Looking back at the description of this bug... Can a user do anything super awful in Terminal that they can't do using the phone in general? Anything that requires sudo will require the user's passcode already.