nRF52840 bonded devices

RE: nRF52840 bonded devices

Kenneth — Wed, 25 Nov 2020 17:15:27 GMT

In BLE it is not configurable (PASSKEY_LENGTH must be 6). So maybe Android discard the last 2-digits?

case BLE_GAP_EVT_PASSKEY_DISPLAY:
{
    char passkey[PASSKEY_LENGTH + 1];
    memcpy(passkey, p_ble_evt->evt.gap_evt.params.passkey_display.passkey, PASSKEY_LENGTH);
    passkey[PASSKEY_LENGTH] = 0;

    NRF_LOG_INFO("Passkey: %s", nrf_log_push(passkey));
} break;

Best regards,
Kenneth

RE: nRF52840 bonded devices

Dani — Wed, 25 Nov 2020 16:59:10 GMT

I'll go back to 6 digit?

Is this code internally used for authentication? Could the 8-digit passkey be the reason of my problem with Apple? (It works fine with Android...)

Dani

RE: nRF52840 bonded devices

Kenneth — Wed, 25 Nov 2020 16:31:47 GMT

8-digit passkey? It should be 6 digit in BLE.

Best regards,
Kenneth

RE: nRF52840 bonded devices

Dani — Wed, 25 Nov 2020 08:22:17 GMT

Hi,

Here you have the sniffer trace in following situation:

My device was advertising and using nRF Connect (ioS) I have been able to connect and receive some data. When I want to write into a characteristic, I'm prompted for the passkey: when entering it, it is always impossible and device disconnects... (This happens at item 3359 in trace and LL_TERMINATE_IND is received)

Hope to solve this.devzone.nordicsemi.com/.../IoS_5F00_pairing_5F00_problem.pcapng

RE: nRF52840 bonded devices

Dani — Tue, 24 Nov 2020 17:01:19 GMT

Hi Kenneth,

I've sniffer already working, but what information do you need to be catched?

As I'm using a 8-digit passkey, I have entered this passkey into Wireshark passkey field. This is right?

I'm deeping a bit more into this application, but meanwhile, if you can detail the information that is useful for you, it will be great!!!

All the best,

Dani.

RE: nRF52840 bonded devices

Kenneth — Tue, 24 Nov 2020 12:56:59 GMT

Are you able to make an on-air sniffer log using nrf sniffer?
https://www.nordicsemi.com/Software-and-tools/Development-Tools/nRF-Sniffer-for-Bluetooth-LE
https://infocenter.nordicsemi.com/topic/ug_sniffer_ble/UG/sniffer_ble/intro.html

Best regards,
Kenneth

RE: nRF52840 bonded devices

Dani — Mon, 23 Nov 2020 08:13:58 GMT

Do you have any other suggestion regarding IoS fucntionality?

I've followed gls example, and everything seems to match but I continue having the same problem when being requested for the passkey: impossible to connect!!

Dani

RE: nRF52840 bonded devices

Dani — Thu, 19 Nov 2020 13:38:38 GMT

OK. Thank you. I'll implement it...

And what about my last comment:: IoS connection and PM_EVT_CONN_SEC_FAILED? Debugging I've seen that reported error (p_evt.params.conn_sec_failed.error) is 0x0088

RE: nRF52840 bonded devices

Kenneth — Thu, 19 Nov 2020 10:42:37 GMT

[quote user="dtarrago"]I suppose you mean to call pm_peer_count() in while() loop (main). And in what regards call to pm_peer_ranks_get and pm_peer_delete: which is the best place to implement them? In the same while loop or inside a certain event in pm_evt_handler? And, it is necessary to call pm_peer_rang_highest() when the event PM_EVT_BONDED_PEER_CONNECTED is given?[/quote]

I would suggest to only call pm_peer_count() in the beginning of main() and on disconnect event. If pm_peer_count() > N, then call pm_peer_ranks_get() to get the 'p_lowest_ranked_peer' and delete it by calling pm_peer_delete(lowest_ranked_peer). There is no need to call pm_peer_rang_highest() from the application, it will already be handled by peer manager if you have enabled PM_PEER_RANKS_ENABLED in sdk_config.h and running pm_handler_flash_clean().

RE: nRF52840 bonded devices

Dani — Thu, 19 Nov 2020 10:18:16 GMT

In what regards connection with IoS: I have followed the example you have suggested and now IoS is requesting me the passkey. Nevertheless, when I write the passkey, the PM_EVT_CONN_SEC_FAILED event is received. Which can be the reason? For clarification: I'm using a 8-digit passkey.

Dani

RE: nRF52840 bonded devices

Dani — Thu, 19 Nov 2020 07:31:30 GMT

You said "You can for instance in beginning of main() call pm_peer_count() to find the numbers of peer bonded, and if you have more than 5 peers bonded you can call pm_peer_ranks_get() to get the 'p_lowest_ranked_peer' and delete it by calling pm_peer_delete(lowest_ranked_peer)."

I suppose you mean to call pm_peer_count() in while() loop (main). And in what regards call to pm_peer_ranks_get and pm_peer_delete: which is the best place to implement them? In the same while loop or inside a certain event in pm_evt_handler? And, it is necessary to call pm_peer_rang_highest() when the event PM_EVT_BONDED_PEER_CONNECTED is given?

On the other side, I will compare my application with the one you suggested in order to make my application working with IoS devices. I will keep you informed.

Dani

RE: nRF52840 bonded devices

Kenneth — Wed, 18 Nov 2020 18:58:00 GMT

[quote user="dtarrago"]Thank you for the bonding inputs. In what regards this: I'm already calling 'pm_handelr_flash_clean()' in pm_evt_handler. Should it be enough to be sure bonding space will not be full? Should I also call 'pm_handler_flash_clean_on_return' when NRF_ERROR_STORAGE_FULL event is given? And I guess, that using this fucntions, it is not necessary to call pm_peer_delete(), right?[/quote]

It should be sufficient to call pm_handler_flash_clean() in pm_evt_handler(). You can find for instance that pm_handler_flash_clean() will already handle PM_EVT_STORAGE_FULL.

It's not necessary to delete bonds no, but I think it may be a good idea to limit the number of bonds overall (to avoid potentially old peers to connect).

You can for instance in beginning of main() call pm_peer_count() to find the numbers of peer bonded, and if you have more than 5 peers bonded you can call pm_peer_ranks_get() to get the 'p_lowest_ranked_peer' and delete it by calling pm_peer_delete(lowest_ranked_peer).

I do not understand why Apple don't trigger passkey here no, do you have an on-air sniffer log (e.g. nRF Sniffer)? For comparison you may try take a look at the code inside the glucose application example in the SDK. This example implements LESC bonding with passkey. This example can be found in folder \examples\ble_peripheral\ble_app_gls and the documentation from the infocenter is found here.

Kenneth

RE: nRF52840 bonded devices

Dani — Wed, 18 Nov 2020 09:09:50 GMT

Hi Kenneth,

Thank you for the bonding inputs. In what regards this: I'm already calling 'pm_handelr_flash_clean()' in pm_evt_handler. Should it be enough to be sure bonding space will not be full? Should I also call 'pm_handler_flash_clean_on_return' when NRF_ERROR_STORAGE_FULL event is given? And I guess, that using this fucntions, it is not necessary to call pm_peer_delete(), right?

In what regards connection with Apple device: by using nRFConnect app, I'm able to read data that my device is sending without being asked for a passkey. If I want to send some data, then I'm asked for the passkey. But, as in Android, I should be asked for a passkey when connecting to device.

In what regards services and characterisitics: for each service, I have one characteristic to send data (like button example) and another one to received data (like LED example).

In what regards 'button example', when adding the characteristic:

......

ble_gatts_char_md_t char_md;
ble_gatts_attr_md_t cccd_md;
ble_gatts_attr_t attr_char_value;
ble_uuid_t ble_uuid;
ble_gatts_attr_md_t attr_md;

memset(&cccd_md, 0, sizeof(cccd_md));

BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);
//BLE_GAP_CONN_SEC_MODE_SET_ENC_WITH_MITM(&cccd_md.write_perm);

cccd_md.vloc = BLE_GATTS_VLOC_STACK;

memset(&char_md, 0, sizeof(char_md));

char_md.char_props.read = 1;
char_md.char_props.notify = 1;
char_md.p_char_user_desc = NULL;
char_md.p_char_pf = NULL;
char_md.p_user_desc_md = NULL;
char_md.p_cccd_md = &cccd_md;
char_md.p_sccd_md = NULL;

ble_uuid.type = p_lbs->uuid_type;
ble_uuid.uuid = FABRICA_UUID_TX_CHAR;

memset(&attr_md, 0, sizeof(attr_md));

BLE_GAP_CONN_SEC_MODE_SET_ENC_WITH_MITM(&attr_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_NO_ACCESS(&attr_md.write_perm);

attr_md.vloc = BLE_GATTS_VLOC_STACK;
attr_md.rd_auth = 0;
attr_md.wr_auth = 0;
attr_md.vlen = 0;

memset(&attr_char_value, 0, sizeof(attr_char_value));

attr_char_value.p_uuid = &ble_uuid;
attr_char_value.p_attr_md = &attr_md;
attr_char_value.init_len = sizeof(u8);
attr_char_value.init_offs = 0;
attr_char_value.max_len = BLE_TAMANY_FABRICA_RX_TX_CHAR;
attr_char_value.p_value = NULL;

return sd_ble_gatts_characteristic_add(p_lbs->service_handle, &char_md,
&attr_char_value,
&p_lbs->tx_char_handles);

....

And in what regards 'LED example':

....

u32 err_code;
ble_gatts_char_md_t char_md;
ble_gatts_attr_t attr_char_value;
ble_uuid_t ble_uuid;
ble_gatts_attr_md_t attr_md;

//Metadata Structure for the Characteristic, which has info about properties available (read, write, notification,...)
memset(&char_md, 0, sizeof(char_md));

char_md.char_props.read = 1;
char_md.char_props.write = 1;
char_md.p_char_user_desc = NULL;
char_md.p_char_pf = NULL;
char_md.p_user_desc_md = NULL;
char_md.p_cccd_md = NULL;
char_md.p_sccd_md = NULL;

ble_uuid.type=p_lbs->uuid_type;
ble_uuid.uuid=FABRICA_UUID_RX_CHAR;

//attr_md: Description of the value attribute
memset(&attr_md, 0, sizeof(attr_md));

BLE_GAP_CONN_SEC_MODE_SET_ENC_WITH_MITM(&attr_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_ENC_WITH_MITM(&attr_md.write_perm);

attr_md.vloc = BLE_GATTS_VLOC_STACK;
attr_md.rd_auth = 0;
attr_md.wr_auth = 0;
attr_md.vlen = 0;

memset(&attr_char_value, 0, sizeof(attr_char_value));

attr_char_value.p_uuid = &ble_uuid;
attr_char_value.p_attr_md = &attr_md;
attr_char_value.init_offs = 0;
attr_char_value.max_len = BLE_TAMANY_FABRICA_RX_TX_CHAR;
attr_char_value.p_value = NULL;

err_code = sd_ble_gatts_characteristic_add(p_lbs->service_handle, &char_md,
&attr_char_value,
&p_lbs->rx_char_handles);
if (err_code != NRF_SUCCESS)
{
return err_code;
}

return NRF_SUCCESS;

....

This is perfectly working on Android. Which is the difference with Apple?

Dani

RE: nRF52840 bonded devices

Kenneth — Tue, 17 Nov 2020 15:04:47 GMT

In general you may find documentation useful:
https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.0.2/group__peer__manager.html

There is no specific limit to the number of bonds that the peer manager can handle. So typically you can call pm_peer_count(), use pm_next_peer_id_get() to for instance call pm_peer_delete() if you exceed the number of bonds you want to support.

For instance to loop through stored bonds you can call the following in a while()-loop:

pm_peer_id_t peer_id;
peer_id = pm_next_peer_id_get(PM_PEER_ID_INVALID);        

while ((peer_id != PM_PEER_ID_INVALID))
{
    // You can delete the bond if you like by calling pm_peer_delete(peer_id)
    
    peer_id = pm_next_peer_id_get(peer_id);
}

Typically you can include pm_handler_flash_clean() in pm_evt_handler(), such that if flash storage is full, it will delete the oldest bond that have not been used.

I do not understand why Apple does not display a pin code, are you sure you have configured characteristics which require MITM security level?