applications: nrf5340_audio: Automatic SIRK generation

- Generate SIRK based on username when using buildprog
- OCT-3666

Signed-off-by: Alexander Svensen <alexander.svensen@nordicsemi.no>
(cherry picked from commit 9947f48)

Author: alexsven

applications/nrf5340_audio/doc/building.rst

@@ -68,6 +68,9 @@ When preparing the JSON file, update the following fields:
 * ``location`` - This field is valid only for headsets.
   It sets the location on which the headset is meant to work, especially when using the :ref:`default CIS transport mode configuration <nrf53_audio_transport_mode_configuration>`.
   For more information, see :ref:`nrf53_audio_app_configuration_headset_location`.
+* ``sirk`` - This field sets the SIRK for the device set, which is used in the unicast applications.
+  The SIRK must be 16 characters long and cannot be the default SIRK defined in the Kconfig file (``NRF5340_TWS_DEMO``).
+  If the default SIRK is used, the script will raise an error and stop building.
 
 .. _nrf53_audio_app_building_script_running:
 

applications/nrf5340_audio/tools/buildprog/buildprog.py

@@ -53,6 +53,8 @@
 TARGET_RELEASE_FOLDER = "build_release"
 TARGET_DEBUG_FOLDER = "build_debug"
 
+DEFAULT_SIRK = "NRF5340_TWS_DEMO"
+
 MAX_USER_NAME_LEN = 248 - len('\0')
 
 
@@ -99,7 +101,7 @@ def __print_dev_conf(device_list):
 
 
 def __build_cmd_get(core: Core, device: AudioDevice, build: BuildType,
-                    pristine, options):
+                    pristine, options, sirk=""):
 
     build_cmd = (f"west build {TARGET_AUDIO_FOLDER} "
                  f"-b {TARGET_BOARD_NRF5340_AUDIO_DK_APP_NAME} "
@@ -143,6 +145,14 @@ def __build_cmd_get(core: Core, device: AudioDevice, build: BuildType,
     else:
         if device == AudioDevice.headset:
             overlay_flag = f" -DEXTRA_CONF_FILE={UNICAST_SERVER_OVERLAY}"
+
+            if sirk == DEFAULT_SIRK:
+                raise ValueError("Default SIRK is not allowed. Please set a custom SIRK in the JSON file.")
+
+            if len(sirk) != 16:
+                raise ValueError("SIRK must be 16 characters long")
+
+            device_flag += " -DCONFIG_BT_SET_IDENTITY_RESOLVING_KEY=\\\"" + sirk + "\\\""
         else:
             overlay_flag = f" -DEXTRA_CONF_FILE={UNICAST_CLIENT_OVERLAY}"
 
@@ -156,13 +166,14 @@ def __build_cmd_get(core: Core, device: AudioDevice, build: BuildType,
     return build_cmd, dest_folder, device_flag, release_flag, overlay_flag
 
 
-def __build_module(build_config, options):
+def __build_module(build_config, options, sirk=""):
     build_cmd, dest_folder, device_flag, release_flag, overlay_flag = __build_cmd_get(
         build_config.core,
         build_config.device,
         build_config.build,
         build_config.pristine,
         options,
+        sirk,
     )
     west_str = f"{build_cmd} -d {dest_folder} "
 
@@ -196,10 +207,10 @@ def __find_snr():
 def __populate_hex_paths(dev, options):
     """Poplulate hex paths where relevant"""
 
-    _, temp_dest_folder, _, _, _ = __build_cmd_get(Core.app, dev.nrf5340_audio_dk_dev, options.build, options.pristine, options)
+    _, temp_dest_folder, _, _, _ = __build_cmd_get(Core.app, dev.nrf5340_audio_dk_dev, options.build, options.pristine, options, dev.sirk)
     dev.hex_path_app = temp_dest_folder / "nrf5340_audio/zephyr/zephyr.hex"
 
-    _, temp_dest_folder, _, _, _ = __build_cmd_get(Core.net, dev.nrf5340_audio_dk_dev, options.build, options.pristine, options)
+    _, temp_dest_folder, _, _, _ = __build_cmd_get(Core.net, dev.nrf5340_audio_dk_dev, options.build, options.pristine, options, dev.sirk)
     dev.hex_path_net = temp_dest_folder / "ipc_radio/zephyr/zephyr.hex"
 
 
@@ -350,7 +361,17 @@ def __main():
     # Then run git update-index --skip-worktree FILENAME to avoid changes
     # being pushed
     with AUDIO_KIT_SERIAL_NUMBERS_JSON.open() as f:
-        dev_arr = json.load(f)
+        json_data = json.load(f)
+
+    # Extract SIRK and devices from the new JSON structure
+    if "devices" in json_data:
+        dev_arr = json_data["devices"]
+        sirk = json_data.get("sirk", "")
+    else:
+        # Fallback for old format (array at root level)
+        dev_arr = json_data
+        sirk = DEFAULT_SIRK
+
     device_list = []
     for dev in dev_arr:
         if AudioDevice[dev["nrf5340_audio_dk_dev"]] == AudioDevice.headset:
@@ -387,6 +408,7 @@ def __main():
             snr_connected=(dev["nrf5340_audio_dk_snr"] in boards_snr_connected),
             recover_on_fail=options.recover_on_fail,
             nrf5340_audio_dk_dev=AudioDevice[dev["nrf5340_audio_dk_dev"]],
+            sirk=sirk,
             cores=cores,
             devices=devices,
             _only_reboot=options.only_reboot,
@@ -431,7 +453,7 @@ def __main():
                     )
 
         for build_cfg in build_configs:
-            __build_module(build_cfg, options)
+            __build_module(build_cfg, options, sirk)
 
     # Build step finished
     # Program step start

applications/nrf5340_audio/tools/buildprog/nrf5340_audio_dk_devices.json

@@ -1,17 +1,26 @@
-[
- {
-        "nrf5340_audio_dk_snr": 1000,
-        "nrf5340_audio_dk_dev": "headset",
-        "location": ["FRONT_LEFT"]
- },
- {
-        "nrf5340_audio_dk_snr": 1000,
-        "nrf5340_audio_dk_dev": "gateway",
-        "location": ["NA"]
- },
- {
-        "nrf5340_audio_dk_snr": 1000,
-        "nrf5340_audio_dk_dev": "headset",
-        "location": ["FRONT_RIGHT"]
- }
-]
+{
+       "sirk": "NRF5340_TWS_DEMO",
+       "devices": [
+              {
+                     "nrf5340_audio_dk_snr": 1000,
+                     "nrf5340_audio_dk_dev": "headset",
+                     "location": [
+                            "FRONT_LEFT"
+                     ]
+              },
+              {
+                     "nrf5340_audio_dk_snr": 1000,
+                     "nrf5340_audio_dk_dev": "gateway",
+                     "location": [
+                            "NA"
+                     ]
+              },
+              {
+                     "nrf5340_audio_dk_snr": 1000,
+                     "nrf5340_audio_dk_dev": "headset",
+                     "location": [
+                            "FRONT_RIGHT"
+                     ]
+              }
+       ]
+}

applications/nrf5340_audio/tools/buildprog/nrf5340_audio_dk_devices.py

@@ -105,6 +105,8 @@ class DeviceConf:
     cores: InitVar[list[Core]]
     devices: InitVar[list[AudioDevice]]
     _only_reboot: InitVar[SelectFlags]
+    sirk: str = ""  # SIRK for the device set
+
     # Post init variables
     only_reboot: SelectFlags = field(init=False, default=SelectFlags.NOT)
     hex_path_app: Path = field(init=False, default=None)