[BRLTTY] What shall we do with bluetooth passkeys?

[Stéphane Doyon]

On Thu, 16 Nov 2006, Dave Mielke wrote:

>> is there actually any way to change the PIN on a Brailliant to something other
>> than 1234?
>
> If a braille display uses a standard PIN then that's an argument for brltty
> being able to respond to the PIN prompt automatically.

Yes. I'd actually like to know though: can I change it? Does anyone know?

>> Are there any other bluetooth displays out there, and do they allow changing
>> the PIN?
>
> There are models for which the PIN is determined by applying a function to the
> serial number.

Apparently I can change the "BT name", which defaults to the serial 
number, but not the PIN.

>> cause otherwise, it's not a big secret :-) and we can set it without
>> asking the user.
>
> We certainly can. Do we want to grow brltty, though, by building support for it
> into the core or is a general command ultimately the better path to take? We

Depends. How much code are we talking about here? We already mount the 
usbfs for example.

OK I glanced at the passkey-agent.c thingy. It's 300 lines.

I agree that a stand-alone agent might be otherwise useful. And I see what 
seems to be considerable dbus connection and registration boilerplate code 
in passkey-agent.c, which we might not want to maintain inside BRLTTY. If 
that boilerplate code could be factored out, say into a lib, there might 
not be much left.

OTOH, there would still have to be some integration with BRLTTY for 
convenience:
-BRLTTY knows the bluetooth address, and it's a pain to set that up in
two places,
-some displays have a constant passkey.
-ease of setup...

Options might be to have BRLTTY call out to an independent utility, or 
make the utility into a library...

> could, of course, do both, i.e. build the support into brltty and also plead
> with the Bluetooth people for a general command.

We should ask them to include it. We could distribute it with BRLTTY in 
the meantime, for convenience, as a separate utility.

>> Another vaguely related observation: the security implications of putting
>> the PIN on a file are more or less comparable to securing the API key.
>
> Yes, but that's not exactly what I said. I asked if putting the PIN within a
> general file like brltty.conf is a good idea. There's a difference between
> storing the PIN in a general file like that and storing it in a separate file
> which can have more strict access controls applied to it. Also, you don't
> necessarily want to risk your PIN showing up on your screen just because you
> want to make other changes to, or show something in, the main configuration
> file.

Yes, that's what I meant. It should be read from a separate file. Sorry 
for being hasty with my comment. The security aspect doesn't seem to me to 
be a factor in deciding whether or not to support this directly.

-- 
Stéphane Doyon
<s.doyon at videotron.ca>
http://pages.infinit.net/sdoyon/