Hi,
There is no such method to protect services from being discovered, but
this is "by design" as per Bluetooth Core spec [1]. As you said, you
can just protect access on characteristic level by combining
BLE_GATT_CHR_F_XXX_ENC (requires encryption, allows unauthenticated
key) and BLE_GATT_CHR_F_XXX_AUTHEN (requires encryption and
authenticated key) flags.
[1] Core 5.0, Vol 3, Part G, Section 8.1: "The list of services and
characteristics that a device supports is not considered private or
confidential information, and therefore the Service and Characteristic
Discovery procedures shall always be permitted."
Best,
Andrzej
On Tue, Jul 10, 2018 at 10:06 AM Amr Bekhit <amrbek...@gmail.com> wrote:
>
> I've experimented some more. If I declare a characteristic with the
> BLE_GATT_CHR_F_XXX_ENC flags, then accessing that characteristic
> prompts me for a pin code, and if I connect from a previously bonded
> profile, then no pin is requested (as expected). So this seems to work
> fine, in that I can pin code-protect certain characteristics of a
> service and require a pin to access them. However, is it possible to
> pin code-protect connections from the advertising stage? Because at
> the moment, any device can connect to and query the services and
> characteristics of the end device.
>
> Amr
> On Tue, 10 Jul 2018 at 10:12, Amr Bekhit <amrbek...@gmail.com> wrote:
> >
> > Hi Andrzej,
> >
> > Thank you - that does indeed work.
> >
> > I have another question. Bonding now works (i.e. using the nRF52
> > Connect app on Android, I connect to the advertising end device and
> > then bond with it to save the credentials), however I would also like
> > to configure the end device so that it requires a pin when connecting
> > to the advertising device. How would this be realised using Nimble?
> >
> > Thanks
> >
> > Amr
> > On Tue, 10 Jul 2018 at 00:50, Andrzej Kaczmarek
> > <andrzej.kaczma...@codecoup.pl> wrote:
> > >
> > > Hi,
> > >
> > > You code looks ok. However, I noticed strange thing when testing with
> > > Android phone on my side: pairing fails if specified passkey has less
> > > than 6 digits (i.e. <100000). This does not seem to be issue in NimBLE
> > > since the same happens when trying to pair Android with BlueZ while
> > > pairing between NimBLE and BlueZ works just fine. Looks like some
> > > issue in Android LE SC implementation tbh...
> > >
> > > So please try with 6 digits passkey (i.e. >=100000) and it should work.
> > >
> > > Best,
> > > Andrzej
> > >
> > >
> > > On Mon, Jul 9, 2018 at 12:08 PM Amr Bekhit <amrbek...@gmail.com> wrote:
> > > >
> > > > Hi Andrzej,
> > > >
> > > > Below is my GAP event callback function and the console output when I
> > > > attempt to bond with my device (I'm using the Nordic nRF Connect app
> > > > on my phone to interact with the device):
> > > >
> > > > static int bleprph_gap_event(struct ble_gap_event *event, void *arg) {
> > > > int rc = 0;
> > > >
> > > > switch(event->type) {
> > > > case BLE_GAP_EVENT_CONNECT:
> > > > console_printf("Connected\n");
> > > > break;
> > > >
> > > > case BLE_GAP_EVENT_DISCONNECT:
> > > > console_printf("Disconnected\n");
> > > > ble_advertise();
> > > > break;
> > > >
> > > > case BLE_GAP_EVENT_CONN_UPDATE:
> > > > console_printf("Connection updated\n");
> > > > break;
> > > >
> > > > case BLE_GAP_EVENT_CONN_UPDATE_REQ:
> > > > console_printf("Connection update requested\n");
> > > > break;
> > > >
> > > > case BLE_GAP_EVENT_PASSKEY_ACTION: {
> > > > console_printf("Passkey Request. Action: %d, Numcmp: %lu\n",
> > > > event->passkey.params.action,
> > > > event->passkey.params.numcmp);
> > > >
> > > > if (event->passkey.params.action == BLE_SM_IOACT_DISP) {
> > > > struct ble_sm_io pk;
> > > > pk.action = event->passkey.params.action;
> > > > pk.passkey = 4539;
> > > > rc = ble_sm_inject_io(event->passkey.conn_handle, &pk);
> > > > console_printf("ble_sm_inject_io result: %d\n", rc);
> > > > }
> > > > break;
> > > > }
> > > >
> > > > default:
> > > > console_printf("GAP Event: %i\n", event->type);
> > > > }
> > > >
> > > > return rc;
> > > > }
> > > >
> > > > 001039 Passkey Request. Action: 3, Numcmp: 0
> > > > 001040 ble_sm_inject_io result: 0
> > > > 001639 GAP Event: 10
> > > > 002037 Connection updated
> > > > 002037 Disconnected
> > > >
> > > > On the phone, I get requested for a pin number and I enter 4539. After
> > > > that, the end device just disconnects from the bluetooth.
