Setting a static pin to allow pairing

Setting a static pin to allow pairing

[Roy Sigurd Karlsbakk]

Hi all

I'm trying to setup a raspberry pi as a bluetooth host allowing pairing fro=
m a phone, but with a predefined pincode, and I can't find any docs on how =
to do this. I find some on how to do this interactively, but then, this isn=
't meant to be used like that, more like a "blackbox". I've tried to google=
 this quite a bit and reading the docs, but I can't find much. Any idea how=
 to do this?

Also, what I'm trying to end up with, is allowing the pi to place a call th=
rough the phone over bluetooth. I haven't managed to find much docs on this=
 either. Bluetooth on linux is quite a new experience (although I've used L=
inux for >20 years), so thanks for any help

Vennlig hilsen

roy
--
Roy Sigurd Karlsbakk
(+47) 98013356
http://blogg.karlsbakk.net/
GPG Public key: http://karlsbakk.net/roysigurdkarlsbakk.pubkey.txt
--
Hi=C3=B0 g=C3=B3=C3=B0a skaltu =C3=AD stein h=C3=B6ggva, hi=C3=B0 illa =C3=
=AD snj=C3=B3 rita.

Re: Setting a static pin to allow pairing

[Bastien Nocera]

On Mon, 2017-12-18 at 11:28 +0100, Roy Sigurd Karlsbakk wrote:
> Hi all
> 
> I'm trying to setup a raspberry pi as a bluetooth host allowing
> pairing from a phone, but with a predefined pincode, and I can't find
> any docs on how to do this. I find some on how to do this
> interactively, but then, this isn't meant to be used like that, more
> like a "blackbox". I've tried to google this quite a bit and reading
> the docs, but I can't find much. Any idea how to do this?

You can use bluez-tools:
https://github.com/khvzak/bluez-tools

(it's packaged for Debian as well, make sure you have a new enough
version to avoid crashes)

This is an example use:
https://github.com/hadess/CHIP-bluetooth-speaker/blob/master/setup.sh#L73

Cheers

Re: Setting a static pin to allow pairing

[Luiz Augusto von Dentz]

Hi Roy,

On Mon, Dec 18, 2017 at 8:28 AM, Roy Sigurd Karlsbakk <roy@karlsbakk.net> w=
rote:
> Hi all
>
> I'm trying to setup a raspberry pi as a bluetooth host allowing pairing f=
rom a phone, but with a predefined pincode, and I can't find any docs on ho=
w to do this. I find some on how to do this interactively, but then, this i=
sn't meant to be used like that, more like a "blackbox". I've tried to goog=
le this quite a bit and reading the docs, but I can't find much. Any idea h=
ow to do this?

With SSP, introduced in Bluetooth 2.1, there is no longer a need to
have predefined pincode. In case that you don't have any means to
confirm you should be able to use "NoInputNoOutput", you can check how
this is done in bluetoothctl:

https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/client/main.c#n1049

> Also, what I'm trying to end up with, is allowing the pi to place a call =
through the phone over bluetooth. I haven't managed to find much docs on th=
is either. Bluetooth on linux is quite a new experience (although I've used=
 Linux for >20 years), so thanks for any help

You will need a telephony stack such as oFono to do that:
https://github.com/intgr/ofono/blob/master/doc/hfp-overview.txt

In case you are using PulseAudio here is how to setup:
https://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/User/Blu=
etooth/#index5h2

>
> Vennlig hilsen
>
> roy
> --
> Roy Sigurd Karlsbakk
> (+47) 98013356
> http://blogg.karlsbakk.net/
> GPG Public key: http://karlsbakk.net/roysigurdkarlsbakk.pubkey.txt
> --
> Hi=C3=B0 g=C3=B3=C3=B0a skaltu =C3=AD stein h=C3=B6ggva, hi=C3=B0 illa =
=C3=AD snj=C3=B3 rita.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth=
" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



--=20
Luiz Augusto von Dentz

Re: Setting a static pin to allow pairing

[Luiz Augusto von Dentz]

Hi Bastien,

On Mon, Dec 18, 2017 at 9:09 AM, Bastien Nocera <hadess@hadess.net> wrote:
> On Mon, 2017-12-18 at 11:28 +0100, Roy Sigurd Karlsbakk wrote:
>> Hi all
>>
>> I'm trying to setup a raspberry pi as a bluetooth host allowing
>> pairing from a phone, but with a predefined pincode, and I can't find
>> any docs on how to do this. I find some on how to do this
>> interactively, but then, this isn't meant to be used like that, more
>> like a "blackbox". I've tried to google this quite a bit and reading
>> the docs, but I can't find much. Any idea how to do this?
>
> You can use bluez-tools:
> https://github.com/khvzak/bluez-tools
>
> (it's packaged for Debian as well, make sure you have a new enough
> version to avoid crashes)
>
> This is an example use:
> https://github.com/hadess/CHIP-bluetooth-speaker/blob/master/setup.sh#L73

Thats is rather old, and we did have incorporated a lot of the
features in these tools into bluetoothctl, obexctl, etc.

-- 
Luiz Augusto von Dentz

Re: Setting a static pin to allow pairing

[Bastien Nocera]

On Mon, 2017-12-18 at 14:12 -0200, Luiz Augusto von Dentz wrote:
> Hi Bastien,
> 
> On Mon, Dec 18, 2017 at 9:09 AM, Bastien Nocera <hadess@hadess.net>
> wrote:
> > On Mon, 2017-12-18 at 11:28 +0100, Roy Sigurd Karlsbakk wrote:
> > > Hi all
> > > 
> > > I'm trying to setup a raspberry pi as a bluetooth host allowing
> > > pairing from a phone, but with a predefined pincode, and I can't
> > > find
> > > any docs on how to do this. I find some on how to do this
> > > interactively, but then, this isn't meant to be used like that,
> > > more
> > > like a "blackbox". I've tried to google this quite a bit and
> > > reading
> > > the docs, but I can't find much. Any idea how to do this?
> > 
> > You can use bluez-tools:
> > https://github.com/khvzak/bluez-tools
> > 
> > (it's packaged for Debian as well, make sure you have a new enough
> > version to avoid crashes)
> > 
> > This is an example use:
> > https://github.com/hadess/CHIP-bluetooth-speaker/blob/master/setup.
> > sh#L73
> 
> Thats is rather old,

It's been ported to BlueZ 5, and I did some fixing last year when I
needed the functionality it offers.

>  and we did have incorporated a lot of the
> features in these tools into bluetoothctl, obexctl, etc.

Can you actually run bluetoothctl in non-interactive mode, as a
service?

Re: Setting a static pin to allow pairing

[Roy Sigurd Karlsbakk]

>> I'm trying to setup a raspberry pi as a bluetooth host allowing pairing =
from a
>> phone, but with a predefined pincode, and I can't find any docs on how t=
o do
>> this. I find some on how to do this interactively, but then, this isn't =
meant
>> to be used like that, more like a "blackbox". I've tried to google this =
quite a
>> bit and reading the docs, but I can't find much. Any idea how to do this=
?
>=20
> With SSP, introduced in Bluetooth 2.1, there is no longer a need to
> have predefined pincode. In case that you don't have any means to
> confirm you should be able to use "NoInputNoOutput", you can check how
> this is done in bluetoothctl:

Perhaps I'm overseeing something, but I don't quite understand how SSP will=
 help. I'm more concerned about unauthorized bluetooth clients pairing with=
 this than MITM-attacks. I want pairing to be fairly simple, but I need a w=
ay to identify the client.

Vennlig hilsen

roy
--
Roy Sigurd Karlsbakk
(+47) 98013356
http://blogg.karlsbakk.net/
GPG Public key: http://karlsbakk.net/roysigurdkarlsbakk.pubkey.txt
--
Hi=C3=B0 g=C3=B3=C3=B0a skaltu =C3=AD stein h=C3=B6ggva, hi=C3=B0 illa =C3=
=AD snj=C3=B3 rita.

Re: Setting a static pin to allow pairing

[Luiz Augusto von Dentz]

Hi Roy,

On Mon, Dec 18, 2017 at 2:24 PM, Roy Sigurd Karlsbakk <roy@karlsbakk.net> wrote:
>>> I'm trying to setup a raspberry pi as a bluetooth host allowing pairing from a
>>> phone, but with a predefined pincode, and I can't find any docs on how to do
>>> this. I find some on how to do this interactively, but then, this isn't meant
>>> to be used like that, more like a "blackbox". I've tried to google this quite a
>>> bit and reading the docs, but I can't find much. Any idea how to do this?
>>
>> With SSP, introduced in Bluetooth 2.1, there is no longer a need to
>> have predefined pincode. In case that you don't have any means to
>> confirm you should be able to use "NoInputNoOutput", you can check how
>> this is done in bluetoothctl:
>
> Perhaps I'm overseeing something, but I don't quite understand how SSP will help. I'm more concerned about unauthorized bluetooth clients pairing with this than MITM-attacks. I want pairing to be fairly simple, but I need a way to identify the client.

Authorization is a separate concept, usually services will require
certain security level which when not met may cause the pairing
process to kick in, authorization may happen regardless of that if the
device is not trusted. In other words, Paired property tells if the
device if the device has been authenticated and a link-key exists and
Trusted tell if the device can connect without being authorized by the
agent, the 2 properties acts completely independent.

For instance, this is how we handle authorization in bluetoothctl:

https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/client/agent.c#n242

Note that RequestAuthorization is for authorizing a new pairing not a
new connection, which is done by AuthorizeService:

https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc/agent-api.txt#n161
https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc/agent-api.txt#n174

In both cases the device object is given so you can identify who is
pairing/connecting.

-- 
Luiz Augusto von Dentz

Re: Setting a static pin to allow pairing

[Roy Sigurd Karlsbakk]

>>>> I'm trying to setup a raspberry pi as a bluetooth host allowing pairin=
g from a
>>>> phone, but with a predefined pincode, and I can't find any docs on how=
 to do
>>>> this. I find some on how to do this interactively, but then, this isn'=
t meant
>>>> to be used like that, more like a "blackbox". I've tried to google thi=
s quite a
>>>> bit and reading the docs, but I can't find much. Any idea how to do th=
is?
>>>
>>> With SSP, introduced in Bluetooth 2.1, there is no longer a need to
>>> have predefined pincode. In case that you don't have any means to
>>> confirm you should be able to use "NoInputNoOutput", you can check how
>>> this is done in bluetoothctl:
>>
>> Perhaps I'm overseeing something, but I don't quite understand how SSP w=
ill
>> help. I'm more concerned about unauthorized bluetooth clients pairing wi=
th this
>> than MITM-attacks. I want pairing to be fairly simple, but I need a way =
to
>> identify the client.
>=20
> Authorization is a separate concept, usually services will require
> certain security level which when not met may cause the pairing
> process to kick in, authorization may happen regardless of that if the
> device is not trusted. In other words, Paired property tells if the
> device if the device has been authenticated and a link-key exists and
> Trusted tell if the device can connect without being authorized by the
> agent, the 2 properties acts completely independent.
>=20
> For instance, this is how we handle authorization in bluetoothctl:
>=20
> https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/client/agent.c#n2=
42
>=20
> Note that RequestAuthorization is for authorizing a new pairing not a
> new connection, which is done by AuthorizeService:
>=20
> https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc/agent-api.txt=
#n161
> https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc/agent-api.txt=
#n174
>=20
> In both cases the device object is given so you can identify who is
> pairing/connecting.

I see - thanks. This is all pretty new to me. Do you know how I can use blu=
etoothectl or similar tools to script up authorisation with the client with=
out digging deeply into the API?

Vennlig hilsen

roy
--
Roy Sigurd Karlsbakk
(+47) 98013356
http://blogg.karlsbakk.net/
GPG Public key: http://karlsbakk.net/roysigurdkarlsbakk.pubkey.txt
--
Hi=C3=B0 g=C3=B3=C3=B0a skaltu =C3=AD stein h=C3=B6ggva, hi=C3=B0 illa =C3=
=AD snj=C3=B3 rita.