Authentication in PreferencePanes
Authentication in PreferencePanes
- Subject: Authentication in PreferencePanes
- From: "Kevin Bohan" <email@hidden>
- Date: Thu, 01 Nov 2001 18:30:05 +0000
Hi,
This is somewhat related to my previous mailing. I have been considering
whether or not I need to add an authentication control to my preference
pane. However, I could not find a document anywhere that defined under what
circumstances a preference pane should include a lock/unlock control, and
under what conditions the control should appear locked or unlocked.
So I did some investigation myself and found some interesting behavior in
the various System pref panes that include lock controls.
The pref panes I looked at were as follows:
1) The "Login Window" tab of the "Login" pref pane.
2) The "Energy Saver" pref pane.
3) The "Startup Disk" pref pane.
4) The "Users" pref pane.
My conclusions are as follows:
a) If I am logged in as an Administrative user then the lock on all these
System pref panes is always unlocked when I first launch the System
Preferences application. This is regardless of the state of the locks when I
last quit the System Preferences app.
b) Although, this is not what I would intuitively expect, if I then lock any
one of these System pref panes, all the other System pref panes are also
locked. They are all linked. Is this by design?
c) For unlocking the reverse happens, in that all pref panes simultaneously
unlock.
d) Even if I lock the lock, I can usually still access the preference file
saved in /Library/Preferences. For example, lock the lock on the Energy
Saver and go to its preferences file at
/Library/Preferences/com.apple.PowerManagement.plist. Use vi or the Property
List Editor to make changes to the file and you have no problem saving the
changes.
Caveats:
If I lock a pref pane, ie all pref panes, all someone has to do is quit the
System Preferences application and open it again to have unlocked access to
the pref panes. This makes the lock a bit pointless, what?
What's the point of the lock when I'm an admin user. Is it to prevent
someone coming up to your machine and making changes while you're logged in.
If that's the case, then it shouldn't be this easy to get around, surely!
e) If I am logged in as a non-administrator whenever I open the System
Preferences all locks are always locked.
f) Again all locks are linked. Locking/unlocking one affects all other
locks.
g) You cannot easily access the /Library/Preference files directly, so no
loophole there.
Is this the way it's supposed to work. If so, then where is this documented.
In either case, I propose that this stuff should be documented, especially
as we can now legitimately write Pref panes. The documentation should cover:
1) Under what circumstances should you include a lock/unlock mechanism.
2) When it should appear locked vs unlocked, if that's something you have to
code for.
I also propose that the lock/unlock control called NIAuthenticationButton
should be made publicly available so that we don't all start implementing
slightly different versions of this, very useful and possibly very common,
control in the context of preference panes.
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