nRF54L15 enabled L4 connection

RE: nRF54L15 enabled L4 connection

Einar Thorsrud — Mon, 24 Feb 2025 08:35:42 GMT

I am not sure I understand. Can you elaborate?

Not that generally, on BLE security requierements are per characeristic (and separate for read and write). So if you requier a specific security level for some or all of your characteristics, set that as a requierment as shown in my previous post. Also, I want to mention that you can enforce LE Secure pairing if you want, by using CONFIG_BT_SMP_SC_ONLY=y as demonstrated in the Peripheral SC-only sample.

RE: nRF54L15 enabled L4 connection

hiteshk014 — Mon, 24 Feb 2025 07:00:16 GMT

If we remove these authentications from the defined characteristics to enable data transactions in the nRF Connect app (iOS), how will we be able to maintain L4 security during data transfer for our intended purpose

RE: nRF54L15 enabled L4 connection

Einar Thorsrud — Thu, 20 Feb 2025 09:56:31 GMT

Hi Hansraj,

The LBS sample does not requier security on the characteristics, and therefore, iOS will never initiate pairing/bonding for it (for the reasons outlined in my previous post). If you want to pair with the LBS sample using iOS, you need to modify the service. You can do that by modifying nrf/subsys/bluetooth/services/lbs.c as shown in this diff:

diff --git a/subsys/bluetooth/services/lbs.c b/subsys/bluetooth/services/lbs.c
index 2db564e8fa..fbd9724009 100644
--- a/subsys/bluetooth/services/lbs.c
+++ b/subsys/bluetooth/services/lbs.c
@@ -100,18 +100,18 @@ BT_GATT_PRIMARY_SERVICE(BT_UUID_LBS),
 #ifdef CONFIG_BT_LBS_POLL_BUTTON
        BT_GATT_CHARACTERISTIC(BT_UUID_LBS_BUTTON,
                               BT_GATT_CHRC_READ | BT_GATT_CHRC_NOTIFY,
-                              BT_GATT_PERM_READ, read_button, NULL,
+                              BT_GATT_PERM_READ_AUTHEN, read_button, NULL,
                               &button_state),
 #else
        BT_GATT_CHARACTERISTIC(BT_UUID_LBS_BUTTON,
                               BT_GATT_CHRC_READ | BT_GATT_CHRC_NOTIFY,
-                              BT_GATT_PERM_READ, NULL, NULL, NULL),
+                              BT_GATT_PERM_READ_AUTHEN, NULL, NULL, NULL),
 #endif
        BT_GATT_CCC(lbslc_ccc_cfg_changed,
-                   BT_GATT_PERM_READ | BT_GATT_PERM_WRITE),
+               BT_GATT_PERM_READ_AUTHEN | BT_GATT_PERM_WRITE_AUTHEN),
        BT_GATT_CHARACTERISTIC(BT_UUID_LBS_LED,
                               BT_GATT_CHRC_WRITE,
-                              BT_GATT_PERM_WRITE,
+                              BT_GATT_PERM_WRITE_AUTHEN,
                               NULL, write_led, NULL),
 );

With this, when you attemt to for instance read the button state, pairing will be initated (note that LESC will be used, and the pass key will be printed in the UART log).

RE: nRF54L15 enabled L4 connection

Hansraj Gavali — Thu, 20 Feb 2025 09:22:06 GMT

Hi Team,

As per Exercise 1 - Nordic Developer Academy, Hitesh has mentioned in his query that he has followed each step provided in the exercise. We tested the BLE connection with Android and iOS Device. Android bluetooth connection works perfectly as per the exercise using nrf Connect App but when the same thing is tried with iPhone nrf Connect App it gets connected but we are not able to see the pairing alert pop up.

Can you help us to find whether something thing is missed or we haven't considered in the code?

Thank you,

Regards,

Hansraj

RE: nRF54L15 enabled L4 connection

Einar Thorsrud — Wed, 19 Feb 2025 14:22:59 GMT

Hi Hitesh,

Can you elaborate on how you tested and how it did not work? The iOS Bluetooth APIs are quite limited, so there is no way for an iOS app (like nRF Connect for iOS) to initiate pairing/bonding explicitly. However, when attempting to access a characteristic and that is prevented due to permissions, the iOS Bleutooth stack will initiate pairing/bonding. Did that not happen when you tested?

Br,

Einar