| NimBLE Host Identity Reference |
| ------------------------------ |
| |
| Introduction |
| ~~~~~~~~~~~~ |
| |
| The identity API provides facilities for querying and configuring your device's addresses. BLE's addressing scheme is |
| quite involved; the summary that follows is only a brief introduction. |
| |
| BLE defines four address types: |
| |
| +---------------------------------+---------------------------------------------------------------------------------------------------+-------------+----------------------------------------------+ |
| | Type | Description | Identity? | Configured with | |
| +=================================+===================================================================================================+=============+==============================================+ |
| | Public | Address assigned by manufacturer; the three most significant bytes form the manufacturer's OUI. | Yes | N/A; read from controller at startup. | |
| +---------------------------------+---------------------------------------------------------------------------------------------------+-------------+----------------------------------------------+ |
| | Static random | Randomly generated address. | Yes | *ble_hs_id_set_rnd()* | |
| +---------------------------------+---------------------------------------------------------------------------------------------------+-------------+----------------------------------------------+ |
| | Resolvable private (RPA) | Address randomly generated from an identity address and an identity resolving key (IRK). | No | N/A; generated by controller periodically. | |
| +---------------------------------+---------------------------------------------------------------------------------------------------+-------------+----------------------------------------------+ |
| | Non-resolvable private (NRPA) | Randomly generated address. | No | *ble_hs_id_set_rnd()* | |
| +---------------------------------+---------------------------------------------------------------------------------------------------+-------------+----------------------------------------------+ |
| |
| Identity Addresses |
| ^^^^^^^^^^^^^^^^^^ |
| |
| The third column in the above table indicates the *identity* property of each address type. An identity address never |
| changes, and a device can be identified by one of its unique identity addresses. |
| |
| Non-identity addresses are used by devices supporting BLE privacy. A device using the privacy feature frequently changes |
| its own address to a newly-generated non-identity address. By cycling its address, the device makes it impossible for |
| eavesdroppers to track its location. |
| |
| A device can have up to two identity addresses at once: one public and one static random. As indicated in the above table, |
| the public identity address cannot be configured; the static random identity address can be set by calling *ble_hs_id_set_rnd()*. |
| |
| The address type is selected on a per-GAP-procedure basis. Each time you initiate a GAP procedure, you indicate which |
| address type the device should use for the duration of the procedure. |
| |
| Header |
| ~~~~~~ |
| |
| .. code-block:: cpp |
| |
| #include "host/ble_hs.h" |