Questions about BLE security settings

[Terutaka Takeuji]

Hello, I'm an engineer living in Japan.

【Development environment】
"PCA10040 (nRF52832)" x 2 (central/peripheral)
"SDK:17.1.0"
"IDE:Segger Embedded Studio for ARM7.10a"

This is a question regarding BLE security settings.

Below are the security measures I would like to implement on the peripheral side.

●Security settings that I want to set
1. When connecting for the first time, allow connections from any central device.

2. For the second and subsequent connections, only the central device connected the first time will be accepted.
　* It does not appear when searching from the central device.

3. Delete connection information only when a specific button is pressed, and accept only the central device when connecting for the first time.

I used "ble_app_hids_keyboard" stored in the SDK of Ver17.1.0 as a reference.
Set up security using “peer manager” + “whitelist”
I ported it to a program I created, but the connection refusal behavior did not work.

When you check the log output from the "ble_app_hids_keyboard" sample program,
I understand that if the following log is output, the connection will be refused from the second generation.

"<info> app: m_whitelist_peer_cnt 1, MAX_PEERS_WLIST 8"
In the program I created, even if I connect from central
The connection could not be refused because the status did not change from "m_whitelist_peer_cnt 0".
I have confirmed that the advertisement signal from the peripheral is received by the central and is working.

Question 1)
Please tell me the conditions under which "m_whitelist_peer_cnt" is counted up in the sample program "ble_app_hids_keyboard".

Question 2)
Please let me know if there is a way to deny connections from the second device onwards using peer manager.
　
Question 3)
It seems possible to make the whitelist work without using a peer manager.
Please tell me the disadvantages (risks) in that case.
*This is the code written in "nrf_dfu_ble.c".

Question 4)
Please tell me the recommended method for implementing the above "security settings that I want to set".
It would be helpful if you could tell me with sample code.

[Hung Bui]

Hi, 

Please clarify, when you tested with the ble_app_his_keyboard, the security feature of the example is what you need, correct ? 
This means you can pair with a central, after that the m_whitelist_peer_cnt will be increased. You can't connect with other centrals. If you want to allow a new central to connect you press button 2 (BTN_ID_WHITELIST_OFF) then the device will advertise openly and allow ne central to connect. 

If that's what you need, then we will need to look into why in your application it didn't work that way. m_whitelist_peer_cnt  should be increased if you do bonding with the central device and the bond information is stored (handled by peer manager automatically). You need to make sure that bonding is enabled (SEC_PARAM_BOND=1)

[Terutaka Takeuji]

Mr. Hung Bui, thank you for your reply.
I apologize for not being able to reply as I have been away for a long time.
I started work yesterday for the first time in a while, but the problem is still not resolved.

I understand the confirmation contents of the sample program "ble_app_his_keyboard".
I understand that pressing button 2 (BTN_ID_WHITELIST_OFF) to reset will remove the whitelist information.
"SEC_PARAM_BOND=1" was the same in the program I created, so there is no problem.

I asked this question because I wanted to port the whitelist to a program I was creating using "ble_app_his_keyboard" as a reference, but the method using a peer manager required the use of the "ble_advertising.c" module. When I ported this to a program I was writing, the build succeeded, but I found that the functionality I was building was affected.
Therefore, we are considering doing away with dynamic whitelisting using peer managers.

Starting today, I would like to implement a dynamic whitelist without using a peer manager.
I would like to apply a dynamic whitelist using the DFU method using "nrf_dfu_ble.c" as a reference.
However, I am having trouble finding any reference materials even after searching on DevZone and the Internet.
I found multiple tickets asking similar questions to mine, but no proper answers.

question)
Please let me know if there is a sample program that implements a dynamic whitelist on the peripheral side without using a peer manager.
I would like to know what kind of sample programs I can build if I only have DFU samples.

thank you.

[Hung Bui]

Hi 輝隆, 

The problem with doing whitelist as in nrf_dfu_ble.c is that the code doesn't handle the bonding process itself. It only apply whitelisting from the bonding info it gets from the application. There will be quite some work if you want to make 

My suggestion is to try doing whitelisting advertising with peer manager. 

What you need to do is to call pm_whitelist_set() that will set the whitelist. 

The only thing the ble_advertising module does to enable and disable whitelist is to set or not set the flag BLE_GAP_ADV_FP_FILTER_CONNREQ. The ble_advertising module doesn't populate the whitelist itself. It's the peer manager does the job. You can take a look at line 328 in ble_advertising.c: 

 if (use_whitelist(p_advertising))
    {
        p_adv_params->filter_policy = BLE_GAP_ADV_FP_FILTER_CONNREQ;

        // Set correct flags.
        ret = flags_set(p_advertising, BLE_GAP_ADV_FLAG_BR_EDR_NOT_SUPPORTED);
        VERIFY_SUCCESS(ret);

        p_advertising->adv_evt = BLE_ADV_EVT_FAST_WHITELIST;
    }

So what you need to do is to call whitelist_set() as in main.c in keyboard example. Then use the flag BLE_GAP_ADV_FP_FILTER_CONNREQ instead of BLE_GAP_ADV_FP_ANY for the adv_params.filter_policy when you do advertising. 

[Terutaka Takeuji]

Mr. Hung Bui, thank you for your valuable information.
From this information, I interpreted that it can be operated with a combination of peer manager and whitelist without using "ble_advertising.c".

I started the porting work immediately and the build was successful, but when I checked it with the terminal software, an error occurred.

[Porting work details]
1. Ported the function of the sample code “ble_app_hids_keyboard”
①static void whitelist_set(pm_peer_id_list_skip_t skip)
②static void pm_evt_handler(pm_evt_t const * p_evt)
③static void peer_manager_init(void)

2. Add "peer_manager_init();" to main function

3. Set parameters for "peer_manager_init"
#define SEC_PARAM_BOND 1
#define SEC_PARAM_MITM 0
#define SEC_PARAM_LESC 0
#define SEC_PARAM_KEYPRESS 0
#define SEC_PARAM_IO_CAPABILITIES BLE_GAP_IO_CAPS_NONE
#define SEC_PARAM_OOB 0
#define SEC_PARAM_MIN_KEY_SIZE 7
#define SEC_PARAM_MAX_KEY_SIZE 16

sec_param.bond = SEC_PARAM_BOND;
sec_param.mitm = SEC_PARAM_MITM;
sec_param.lesc = SEC_PARAM_LESC;
sec_param.keypress = SEC_PARAM_KEYPRESS;
sec_param.io_caps = SEC_PARAM_IO_CAPABILITIES;
sec_param.oob = SEC_PARAM_OOB;
sec_param.min_key_size = SEC_PARAM_MIN_KEY_SIZE;
sec_param.max_key_size = SEC_PARAM_MAX_KEY_SIZE;
sec_param.kdist_own.enc = 1;
sec_param.kdist_own.id = 1;
sec_param.kdist_peer.enc = 1;
sec_param.kdist_peer.id = 1;

4. Change filter policy
In the static void advertising_init(void) function
　adv_params.filter_policy = BLE_GAP_ADV_FP_ANY;
↓
　adv_params.filter_policy = BLE_GAP_ADV_FP_FILTER_CONNREQ;

5. Calling whitelist_set
static void advertising_start(void)
{
    ret_code_t err_code;

    whitelist_set(PM_PEER_ID_LIST_SKIP_NO_ID_ADDR);

    err_code = sd_ble_gap_adv_start(m_adv_handle, APP_BLE_CONN_CFG_TAG);
    APP_ERROR_CHECK(err_code);
}

[Terminal software output log]
●filter_policy BLE_GAP_ADV_FP_ANY Normal operation
<info> app_timer: RTC: initialized.
<info> app: Valve Control System started.
<info> app: m_whitelist_peer_cnt 0, MAX_PEERS_WLIST 8
<info> app: Connected
<info> app: Disconnected
<info> app: m_whitelist_peer_cnt 0, MAX_PEERS_WLIST 8

●filter_policy BLE_GAP_ADV_FP_FILTER_CONNREQ Abnormal operation
<info> app_timer: RTC: initialized.
<error> app: Fatal error
<warning> app: System reset

question)
adv_params.filter_policy = BLE_GAP_ADV_FP_FILTER_CONNREQ;
In the above case, <error> app: Fatal error will occur and the app will not be able to operate.
Please tell me how to deal with this issue.
Also, if there are any mistakes in the porting method, please let me know.

reference)
When I checked the behavior of the peer manager by step execution without using "static void pm_evt_handler(pm_evt_t const * p_evt)", I found the following situation.
It did not fit into "case PM_EVT_CONN_SEC_SUCCEEDED:".
Confirm that "case PM_EVT_PEER_DATA_UPDATE_SUCCEEDED:" is entered.

For your reference, I have created a test program where you can check the errors. please confirm.
The error occurs immediately after startup, so you can see it right away in the terminal.

Thank you.

Fullscreen 36087.main.c Download

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/**
 * @brief Blinky Sample Application main file.
 *
 * This file contains the source code for a sample server application using the LED Button service.
 */

#include <stdint.h>
#include <string.h>
#include "nordic_common.h"
#include "nrf.h"
#include "app_error.h"
#include "ble.h"
#include "ble_err.h"
#include "ble_hci.h"
#include "ble_srv_common.h"
#include "ble_advdata.h"
#include "ble_conn_params.h"
#include "nrf_sdh.h"
#include "nrf_sdh_ble.h"
#include "boards.h"
#include "app_timer.h"
#include "app_button.h"
#include "ble_lbs.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_qwr.h"
#include "nrf_pwr_mgmt.h"

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#include "nrf_delay.h"

// white list include -------------------------
#include "peer_manager.h"
#include "peer_manager_handler.h"
// white list include -------------------------

#define ADVERTISING_LED                 BSP_BOARD_LED_0                         /**< Is on when device is advertising. */
#define CONNECTED_LED                   BSP_BOARD_LED_1                         /**< Is on when device has connected. */
#define LEDBUTTON_LED1                  BSP_BOARD_LED_0                         
#define LEDBUTTON_LED2                  BSP_BOARD_LED_1                         
#define LEDBUTTON_LED3                  BSP_BOARD_LED_2                         /**< LED to be toggled with the help of the LED Button Service. */
#define LEDBUTTON_LED4                  BSP_BOARD_LED_3                         /**< LED to be toggled with the help of the LED Button Service. */

static char DEVICE_NAME[15] = "Nordic_0000100";

#define APP_BLE_OBSERVER_PRIO           3                                       /**< Application's BLE observer priority. You shouldn't need to modify this value. */
#define APP_BLE_CONN_CFG_TAG            1                                       /**< A tag identifying the SoftDevice BLE configuration. */

#define APP_ADV_INTERVAL                240                                     /**< The advertising interval (in units of 0.625 ms; this value corresponds to 40 ms). */
#define APP_ADV_DURATION                BLE_GAP_ADV_TIMEOUT_GENERAL_UNLIMITED   /**< The advertising time-out (in units of seconds). When set to 0, we will never time out. */


#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(100, UNIT_1_25_MS)        /**< Minimum acceptable connection interval (0.5 seconds). */
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(200, UNIT_1_25_MS)        /**< Maximum acceptable connection interval (1 second). */
#define SLAVE_LATENCY                   0                                       /**< Slave latency. */
#define CONN_SUP_TIMEOUT                MSEC_TO_UNITS(4000, UNIT_10_MS)         /**< Connection supervisory time-out (4 seconds). */

#define FIRST_CONN_PARAMS_UPDATE_DELAY  APP_TIMER_TICKS(20000)                  /**< Time from initiating event (connect or start of notification) to first time sd_ble_gap_conn_param_update is called (15 seconds). */
#define NEXT_CONN_PARAMS_UPDATE_DELAY   APP_TIMER_TICKS(5000)                   /**< Time between each call to sd_ble_gap_conn_param_update after the first call (5 seconds). */
#define MAX_CONN_PARAMS_UPDATE_COUNT    3                                       /**< Number of attempts before giving up the connection parameter negotiation. */

#define BUTTON_DETECTION_DELAY          APP_TIMER_TICKS(50)                     /**< Delay from a GPIOTE event until a button is reported as pushed (in number of timer ticks). */

#define DEAD_BEEF                       0xDEADBEEF                              /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */

BLE_LBS_DEF(m_lbs);                                                             /**< LED Button Service instance. */
NRF_BLE_GATT_DEF(m_gatt);                                                       /**< GATT module instance. */
NRF_BLE_QWR_DEF(m_qwr);                                                         /**< Context for the Queued Write module.*/

static uint16_t m_conn_handle = BLE_CONN_HANDLE_INVALID;                        /**< Handle of the current connection. */
static uint8_t m_adv_handle = BLE_GAP_ADV_SET_HANDLE_NOT_SET;                   /**< Advertising handle used to identify an advertising set. */
static uint8_t m_enc_advdata[BLE_GAP_ADV_SET_DATA_SIZE_MAX];                    /**< Buffer for storing an encoded advertising set. */
static uint8_t m_enc_scan_response_data[BLE_GAP_ADV_SET_DATA_SIZE_MAX];         /**< Buffer for storing an encoded scan data. */

static void advertising_start(void);
static bool LED_status = false;


// WhiteList Define -------------------------------------------------------------

#define SEC_PARAM_BOND                      1                                          /**< Perform bonding. */
#define SEC_PARAM_MITM                      0                                          /**< Man In The Middle protection not required. */
#define SEC_PARAM_LESC                      0                                          /**< LE Secure Connections not enabled. */
#define SEC_PARAM_KEYPRESS                  0                                          /**< Keypress notifications not enabled. */
#define SEC_PARAM_IO_CAPABILITIES           BLE_GAP_IO_CAPS_NONE                       /**< No I/O capabilities. */
#define SEC_PARAM_OOB                       0                                          /**< Out Of Band data not available. */
#define SEC_PARAM_MIN_KEY_SIZE              7                                          /**< Minimum encryption key size. */
#define SEC_PARAM_MAX_KEY_SIZE              16                                         /**< Maximum encryption key size. */

static pm_peer_id_t      m_peer_id;                                 /**< Device reference handle to the current bonded central. */

// WhiteList Define -------------------------------------------------------------

// WhiteList Process -------------------------------------------------------------

static void whitelist_set(pm_peer_id_list_skip_t skip)
{
    pm_peer_id_t peer_ids[BLE_GAP_WHITELIST_ADDR_MAX_COUNT];
    uint32_t     peer_id_count = BLE_GAP_WHITELIST_ADDR_MAX_COUNT;

    ret_code_t err_code = pm_peer_id_list(peer_ids, &peer_id_count, PM_PEER_ID_INVALID, skip);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_INFO("\tm_whitelist_peer_cnt %d, MAX_PEERS_WLIST %d",
                   peer_id_count,
                   BLE_GAP_WHITELIST_ADDR_MAX_COUNT);

    err_code = pm_whitelist_set(peer_ids, peer_id_count);
    APP_ERROR_CHECK(err_code);
}

static void pm_evt_handler(pm_evt_t const * p_evt)
{
    pm_handler_on_pm_evt(p_evt);
    pm_handler_disconnect_on_sec_failure(p_evt);
    pm_handler_flash_clean(p_evt);

    switch (p_evt->evt_id)
    {
        case PM_EVT_CONN_SEC_SUCCEEDED:
            m_peer_id = p_evt->peer_id;
            break;

        case PM_EVT_PEERS_DELETE_SUCCEEDED:
            advertising_start();
            break;

        case PM_EVT_PEER_DATA_UPDATE_SUCCEEDED:
            if (     p_evt->params.peer_data_update_succeeded.flash_changed
                 && (p_evt->params.peer_data_update_succeeded.data_id == PM_PEER_DATA_ID_BONDING))
            {
                NRF_LOG_INFO("New Bond, add the peer to the whitelist if possible");
                // Note: You should check on what kind of white list policy your application should use.

                whitelist_set(PM_PEER_ID_LIST_SKIP_NO_ID_ADDR);
            }
            break;

        default:
            break;
    }
}

static void peer_manager_init(void)
{
    ble_gap_sec_params_t sec_param;
    ret_code_t           err_code;

    err_code = pm_init();
    APP_ERROR_CHECK(err_code);

    memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));

    // Security parameters to be used for all security procedures.
    sec_param.bond           = SEC_PARAM_BOND;
    sec_param.mitm           = SEC_PARAM_MITM;
    sec_param.lesc           = SEC_PARAM_LESC;
    sec_param.keypress       = SEC_PARAM_KEYPRESS;
    sec_param.io_caps        = SEC_PARAM_IO_CAPABILITIES;
    sec_param.oob            = SEC_PARAM_OOB;
    sec_param.min_key_size   = SEC_PARAM_MIN_KEY_SIZE;
    sec_param.max_key_size   = SEC_PARAM_MAX_KEY_SIZE;
    sec_param.kdist_own.enc  = 1;
    sec_param.kdist_own.id   = 1;
    sec_param.kdist_peer.enc = 1;
    sec_param.kdist_peer.id  = 1;

    err_code = pm_sec_params_set(&sec_param);
    APP_ERROR_CHECK(err_code);

    err_code = pm_register(pm_evt_handler);
    APP_ERROR_CHECK(err_code);
}

// WhiteList Process -------------------------------------------------------------


/**@brief Struct that contains pointers to the encoded advertising data. */
static ble_gap_adv_data_t m_adv_data =
{
    .adv_data =
    {
        .p_data = m_enc_advdata,
        .len    = BLE_GAP_ADV_SET_DATA_SIZE_MAX
    },
    .scan_rsp_data =
    {
        .p_data = m_enc_scan_response_data,
        .len    = BLE_GAP_ADV_SET_DATA_SIZE_MAX

    }
};




/**@brief Function for assert macro callback.
 *
 * @details This function will be called in case of an assert in the SoftDevice.
 *
 * @warning This handler is an example only and does not fit a final product. You need to analyze
 *          how your product is supposed to react in case of Assert.
 * @warning On assert from the SoftDevice, the system can only recover on reset.
 *
 * @param[in] line_num    Line number of the failing ASSERT call.
 * @param[in] p_file_name File name of the failing ASSERT call.
 */
void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
{
    app_error_handler(DEAD_BEEF, line_num, p_file_name);
}


/**@brief Function for the LEDs initialization.
 *
 * @details Initializes all LEDs used by the application.
 */
static void leds_init(void)
{
    bsp_board_init(BSP_INIT_LEDS);
}


/**@brief Function for the Timer initialization.
 *
 * @details Initializes the timer module.
 */
static void timers_init(void)
{
    // Initialize timer module, making it use the scheduler
    ret_code_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for the GAP initialization.
 *
 * @details This function sets up all the necessary GAP (Generic Access Profile) parameters of the
 *          device including the device name, appearance, and the preferred connection parameters.
 */
static void gap_params_init(void)
{
    ret_code_t              err_code;
    ble_gap_conn_params_t   gap_conn_params;
    ble_gap_conn_sec_mode_t sec_mode;

    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

    err_code = sd_ble_gap_device_name_set(&sec_mode,
                                          (const uint8_t *)DEVICE_NAME,
                                          strlen(DEVICE_NAME));

    APP_ERROR_CHECK(err_code);

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

    gap_conn_params.min_conn_interval = MIN_CONN_INTERVAL;
    gap_conn_params.max_conn_interval = MAX_CONN_INTERVAL;
    gap_conn_params.slave_latency     = SLAVE_LATENCY;
    gap_conn_params.conn_sup_timeout  = CONN_SUP_TIMEOUT;

    err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the GATT module.
 */
static void gatt_init(void)
{
    ret_code_t err_code = nrf_ble_gatt_init(&m_gatt, NULL);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the Advertising functionality.
 *
 * @details Encodes the required advertising data and passes it to the stack.
 *          Also builds a structure to be passed to the stack when starting advertising.
 */
static void advertising_init(void)
{
    ret_code_t    err_code;
    ble_advdata_t advdata;
    ble_advdata_t srdata;

    ble_uuid_t adv_uuids[] = {{LBS_UUID_SERVICE, m_lbs.uuid_type}};

    // Build and set advertising data.
    memset(&advdata, 0, sizeof(advdata));

    advdata.name_type          = BLE_ADVDATA_FULL_NAME;
    advdata.include_appearance = true;
    advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;


    memset(&srdata, 0, sizeof(srdata));
    srdata.uuids_complete.uuid_cnt = sizeof(adv_uuids) / sizeof(adv_uuids[0]);
    srdata.uuids_complete.p_uuids  = adv_uuids;

    err_code = ble_advdata_encode(&advdata, m_adv_data.adv_data.p_data, &m_adv_data.adv_data.len);
    APP_ERROR_CHECK(err_code);

    err_code = ble_advdata_encode(&srdata, m_adv_data.scan_rsp_data.p_data, &m_adv_data.scan_rsp_data.len);
    APP_ERROR_CHECK(err_code);

    ble_gap_adv_params_t adv_params;

    // Set advertising parameters.
    memset(&adv_params, 0, sizeof(adv_params));

    adv_params.primary_phy     = BLE_GAP_PHY_1MBPS;
    adv_params.duration        = APP_ADV_DURATION;
    adv_params.properties.type = BLE_GAP_ADV_TYPE_CONNECTABLE_SCANNABLE_UNDIRECTED;
    adv_params.p_peer_addr     = NULL;
    adv_params.filter_policy   = BLE_GAP_ADV_FP_FILTER_CONNREQ; //whitelist
    //adv_params.filter_policy   = BLE_GAP_ADV_FP_ANY;
    adv_params.interval        = APP_ADV_INTERVAL;

    err_code = sd_ble_gap_adv_set_configure(&m_adv_handle, &m_adv_data, &adv_params);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling Queued Write Module errors.
 *
 * @details A pointer to this function will be passed to each service which may need to inform the
 *          application about an error.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void nrf_qwr_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}

static void led_write_handler(uint16_t conn_handle, ble_lbs_t * p_lbs, uint8_t led_state)
{
    ret_code_t  err_code;
    uint32_t  err_code_S;
    switch (led_state)
    {       
      default:
        break;
    }
}



/**@brief Function for initializing services that will be used by the application.
 */
static void services_init(void)
{
    ret_code_t         err_code;
    ble_lbs_init_t     init     = {0};
    nrf_ble_qwr_init_t qwr_init = {0};

    // Initialize Queued Write Module.
    qwr_init.error_handler = nrf_qwr_error_handler;

    err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init);
    APP_ERROR_CHECK(err_code);

    // Initialize LBS.
    init.led_write_handler = led_write_handler;

    err_code = ble_lbs_init(&m_lbs, &init);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the Connection Parameters Module.
 *
 * @details This function will be called for all events in the Connection Parameters Module that
 *          are passed to the application.
 *
 * @note All this function does is to disconnect. This could have been done by simply
 *       setting the disconnect_on_fail config parameter, but instead we use the event
 *       handler mechanism to demonstrate its use.
 *
 * @param[in] p_evt  Event received from the Connection Parameters Module.
 */
static void on_conn_params_evt(ble_conn_params_evt_t * p_evt)
{
    ret_code_t err_code;

    if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED)
    {
        err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
        APP_ERROR_CHECK(err_code);
    }
}


/**@brief Function for handling a Connection Parameters error.
 *
 * @param[in] nrf_error  Error code containing information about what went wrong.
 */
static void conn_params_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@brief Function for initializing the Connection Parameters module.
 */
static void conn_params_init(void)
{
    ret_code_t             err_code;
    ble_conn_params_init_t cp_init;

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

    cp_init.p_conn_params                  = NULL;
    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
    cp_init.start_on_notify_cccd_handle    = BLE_GATT_HANDLE_INVALID;
    cp_init.disconnect_on_fail             = false;
    cp_init.evt_handler                    = on_conn_params_evt;
    cp_init.error_handler                  = conn_params_error_handler;

    err_code = ble_conn_params_init(&cp_init);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for starting advertising.
 */
static void advertising_start(void)
{
    ret_code_t           err_code;

    whitelist_set(PM_PEER_ID_LIST_SKIP_NO_ID_ADDR); //whitelist

    err_code = sd_ble_gap_adv_start(m_adv_handle, APP_BLE_CONN_CFG_TAG);
    APP_ERROR_CHECK(err_code);
}

static void advertising_stop(void)
{
    ret_code_t           err_code;

    err_code = sd_ble_gap_adv_stop(m_adv_handle);
    APP_ERROR_CHECK(err_code);
}

/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    ret_code_t err_code;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            NRF_LOG_INFO("Connected");
            m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
            err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle);
            APP_ERROR_CHECK(err_code);
            
            if (LED_status == false )
            {
                LED_status = true;
                bsp_board_led_on(LEDBUTTON_LED3);
            }else{
                LED_status = false;
                bsp_board_led_off(LEDBUTTON_LED3);
            }
            
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected");
            m_conn_handle = BLE_CONN_HANDLE_INVALID;
            advertising_start();

            break;
       
        case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
            // Pairing not supported
            err_code = sd_ble_gap_sec_params_reply(m_conn_handle,
                                                   BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP,
                                                   NULL,
                                                   NULL);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_DEBUG("PHY update request.");
            ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
            err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GATTS_EVT_SYS_ATTR_MISSING:
            // No system attributes have been stored.
            err_code = sd_ble_gatts_sys_attr_set(m_conn_handle, NULL, 0, 0);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            NRF_LOG_DEBUG("GATT Client Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_TIMEOUT:
            // Disconnect on GATT Server timeout event.
            NRF_LOG_DEBUG("GATT Server Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupt.
 */
static void ble_stack_init(void)
{
    ret_code_t err_code;

    err_code = nrf_sdh_enable_request();
    APP_ERROR_CHECK(err_code);

    // Configure the BLE stack using the default settings.
    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
    APP_ERROR_CHECK(err_code);

    // Enable BLE stack.
    err_code = nrf_sdh_ble_enable(&ram_start);
    APP_ERROR_CHECK(err_code);

    // Register a handler for BLE events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
}

static void log_init(void)
{
    ret_code_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


/**@brief Function for initializing power management.
 */
static void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the idle state (main loop).
 *
 * @details If there is no pending log operation, then sleep until next the next event occurs.
 */
static void idle_state_handle(void)
{
    if (NRF_LOG_PROCESS() == false)
    {
        nrf_pwr_mgmt_run();
    }
}

static void Nrf_Power_Type_init(void)
{
    sd_power_dcdc_mode_set(NRF_POWER_DCDC_ENABLE);
}

/**@brief Function for application main entry.
 */
int main(void)
{
    ret_code_t err_code;
     
    // Initialize.
    log_init();
    leds_init();
    timers_init();

    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    services_init();
    advertising_init();
    conn_params_init();
    Nrf_Power_Type_init();
    peer_manager_init();

    // Start execution.
    NRF_LOG_INFO("System started.");
    advertising_start();

    // Enter main loop.
    while (true)
    {
        idle_state_handle();
    }
}


/**
 * @}
 */

[Hung Bui]

Hi, 

Please enable DEBUG in the project's setting preprocessor symbol so that we would be able to see where the error occurs. 
By having that we would be able to find in the log at exact which line the assert occurs. 

One option you can try is to modify the ble_app_his_keyboard example to not use the ble_advertising.c to do advertising with whitelist. Instead you call sd_ble_gap_adv_start() directly and check if you can do advertising with whitelist or not. 

But it's important that you would be able to turn on DEBUG so that it's easier to find what could be wrong. 

[Terutaka Takeuji]

Thank you for answering.

Is it safe to assume that the cause of the error is unknown?

When I set a breakpoint, it passed up to line 361, but it seems to have stopped at the error check.
"sd_ble_gap_adv_set_configure" is an SVCALL so I cannot track it further.
I believe there is a problem with the execution of "sd_ble_gap_adv_set_configure" on line 360. Is there a workaround?

Sample code main.c
360: err_code = sd_ble_gap_adv_set_configure(&m_adv_handle, &m_adv_data, &adv_params);
361: APP_ERROR_CHECK(err_code);

>Enable DEBUG in the project's settings preprocessor symbols.
The IDE I am using is "EmbeddedStudio for ARM 7.10a", is there such a setting?

I set breakpoints and debug with the following settings in sdk_config.h.

NRF_LOG_BACKEND_RTT_ENABLED 1
NRF_LOG_DEFAULT_LEVEL 3
NRF_LOG_ENABLED

I'm not familiar with debugging methods.
If there is a better debugging method other than the above method, please let me know.
A website that introduces debugging methods is also fine.

Also, was the work I ported the same as Mr. HungBui's idea?
If I'm wrong, please point it out.

If I have time I will try the suggested changes to 'ble_app_his_keyboard'.

Thank you.

[Hung Bui]

Hi, 

To be able to develop an application you should get familiar with debugging. 

You should add DEBUG here: 

Please check what the err_code returns from the function sd_ble_gap_adv_set_configure() . From that we can find what could be wrong. 

You should use the flag BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE instead of BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE because you are using whitelist. 

Please test that you can do advertising and can do pairing (and reconnection ) with peer manager without whitelist first. 
After you have everything working then you can start implementing whitelisting.