[Authentication] Spec review (part 1)

[Eckhart Wörner]

Hi everybody,

last week at the KDE BaWü-Sprint, I had an extensive look at the current draft 
of the spec, and I want to propose several changes:

1) I talked to the D-Bus people and we agreed on that there's no use for 
encryption on D-Bus at all. As soon as you've the possibility to eavesdrop the 
D-Bus communication, you're also able to do a man-in-the-middle attack.
My proposal here is to get rid of encryption completely. This makes 
implementation of client libraries much easier.

2) On the other hand, encryption introduces a lot of ugliness. Secrets are put 
on the bus as byte arrays, at the moment it isn't even specified how 
(decrypted) byte arrays translate to strings afterwards. Getting rid of 
encryption allows to use the D-Bus type system. Two possibilities:
a) secrets are D-Bus variants ("v")
b) overloading for several common types (like "s", "ay" and "a{ss}")

3) Since the spec says that items can be locked / unlocked individually, a 
"Locked" property for the collection makes no sense.

4) There's an artificial separation between items that don't need a Prompt and 
items that do so. I suggest to change this so that as soon as a call *might* 
take some time, a prompt is returned.

5) Unlocking of the secret storage might take some time without ever creating 
a prompt (e.g. hardware needed takes some time to initialize, etc). I suggest 
to rename Prompt to Job.

No diff for those changes yet, there's a part 2 yet to be written.

Eckhart