[Pkg-cups-devel] Bug#616718: cups: Attempting to add a printer gives a forbidden error

[Brian Potkin]

Hello Jonathan,

You wrote:

> so presumably I ought to add myself to group lpadmin.  But in any
> event, the inability to get back to step 2 (the dialog box allowing
> me to choose a username and password) is puzzling.

If you repeated your first two steps but in step 3 gave an incorrect
user/password combination the dialogue box is offered again. What I
think is happening is a two stage process.

First it needs to be determined if you are a user on the machine. I
expect PAM is involved and CUPS is quite happy to reply on what it is
told. The box is re-offered if PAM doesn't like the credentials and CUPS
lets it get on with its job.

Once the user is authenticated the second stage is for CUPS to sort out
whether you are entitled to add printers. Being a member of the lpadmin
group would be one test. If you are not the 'Forbidden' sign is put up.

Now you try again. The first stage is not repeated because PAM is to be
trusted and would get upset if CUPS kept querying its decisions. Which
is why you do not get the dialogue box back. CUPS already knows your
status regarding group membership so just keeps pointing to the sign it
displayed previously. Get a new cookie and it will reconsider.

>From the information given #616718 is almost certainly not a bug.

Cheers,

Brian.