Hi Iulia, On Thu, Aug 29, 2024 at 9:25 AM Iulia Tanasescu <iulia.tanasescu@xxxxxxx> wrote: > > Currently, the user sets the Broadcast Code as an array of bytes > when prompted from the assistant submenu. However, the Bluetooth > Core Specification requires that, on the UI level, the Broadcast > Code shall be represented as a string (Vol 3, Part C, 3.2.6). Interesting, but we could go one step further can hash the string using bt_crypto_AES-CMAC since that would always generate a 16 bits hash, we actually have done something similar for SIRK on main.conf: https://github.com/bluez/bluez/blob/master/src/main.conf#L268 > This commit makes the Broadcast Code be parsed as a string from > the assistant prompt. The bluetoothctl log below shows a Broadcast > Assistant pushing an encrypted stream to a peer: > > client/bluetoothctl > [bluetooth]# [CHG] Controller 00:60:37:31:7E:3F Pairable: yes > [bluetooth]# AdvertisementMonitor path registered > [bluetooth]# scan on > [bluetooth]# [NEW] Device 00:60:37:31:7E:3F 00-60-37-31-7E-3F > [bluetooth]# connect 00:60:37:31:7E:3F > Attempting to connect to 00:60:37:31:7E:3F > [CHG] Device 00:60:37:31:7E:3F Connected: yes > [00-60-37-31-7E-3F]# Connection successful > [00-60-37-31-7E-3F]# [NEW] Device 19:9A:7A:71:E5:8B 19-9A-7A-71-E5-8B > [00-60-37-31-7E-3F]# [NEW] Assistant > /org/bluez/hci0/src_19_9A_7A_71_E5_8B/dev_00_60_37_31_7E_3F/bis1 > [00-60-37-31-7E-3F]# assistant.push > /org/bluez/hci0/src_19_9A_7A_71_E5_8B/dev_00_60_37_31_7E_3F/bis1 > [Assistant] Enter Metadata (auto/value): a > [Assistant] Enter Broadcast Code (auto/value): Borne House > [00-60-37-31-7E-3F]# [CHG] Assistant > /org/bluez/hci0/src_19_9A_7A_71_E5_8B/dev_00_60_37_31_7E_3F/bis1 > State: pending > [00-60-37-31-7E-3F]# Assistant > /org/bluez/hci0/src_19_9A_7A_71_E5_8B/dev_00_60_37_31_7E_3F/bis1 > pushed > [00-60-37-31-7E-3F]# [CHG] Assistant > /org/bluez/hci0/src_19_9A_7A_71_E5_8B/dev_00_60_37_31_7E_3F/bis1 > State: requesting > [00-60-37-31-7E-3F]# [CHG] Assistant > /org/bluez/hci0/src_19_9A_7A_71_E5_8B/dev_00_60_37_31_7E_3F/bis1 > State: active > > The btmon log below shows the way the Broadcast Code string is converted > into a byte array and sent to the peer via GATT: > > bluetoothd[6013]: < ACL Data TX: Handle 0 flags 0x00 dlen 28 > ATT: Write Command (0x52) len 23 > Handle: 0x0040 Type: Broadcast Audio Scan Control Point (0x2bc7) > Data[21]: 02018be5717a9a1900db5e3a02ffff010100000000 > Opcode: Add Source (0x02) > Source_Address_Type: 1 > Source_Address: 19:9A:7A:71:E5:8B > Source_Adv_SID: 0 > Broadcast_ID: 0x3a5edb > PA_Sync_State: Synchronize to PA - PAST not available > PA_Interval: 0xffff > Num_Subgroups: 1 > Subgroup #0: > BIS_Sync State: 0x00000001 > > ACL Data RX: Handle 0 flags 0x01 dlen 2 > ATT: Handle Multiple Value Notification (0x23) len 24 > Length: 0x0014 > Handle: 0x003a Type: Broadcast Receive State (0x2bc8) > Data[20]: 01018be5717a9a1900db5e3a0201010000000000 > Source_ID: 1 > Source_Address_Type: 1 > Source_Address: 19:9A:7A:71:E5:8B > Source_Adv_SID: 0 > Broadcast_ID: 0x3a5edb > PA_Sync_State: Synchronized to PA > BIG_Encryption: Broadcast_Code required > Num_Subgroups: 1 > Subgroup #0: > BIS_Sync State: 0x00000000 > bluetoothd[6013]: < ACL Data TX: Handle 0 flags 0x00 dlen 25 > ATT: Write Command (0x52) len 20 > Handle: 0x0040 Type: Broadcast Audio Scan Control Point (0x2bc7) > Data[18]: 040142c3b8726e6520486f75736500000000 > Opcode: Set Broadcast_Code (0x04) > Source_ID: 1 > Broadcast_Code[16]: 426f726e6520486f7573650000000000 > > ACL Data RX: Handle 0 flags 0x01 dlen 2 > ATT: Handle Multiple Value Notification (0x23) len 24 > Length: 0x0014 > Handle: 0x003a Type: Broadcast Receive State (0x2bc8) > Data[20]: 01018be5717a9a1900db5e3a0202010100000000 > Source_ID: 1 > Source_Address_Type: 1 > Source_Address: 19:9A:7A:71:E5:8B > Source_Adv_SID: 0 > Broadcast_ID: 0x3a5edb > PA_Sync_State: Synchronized to PA > BIG_Encryption: Decrypting > Num_Subgroups: 1 > Subgroup #0: > BIS_Sync State: 0x00000001 > --- > client/assistant.c | 24 ++++++++++++++---------- > 1 file changed, 14 insertions(+), 10 deletions(-) > > diff --git a/client/assistant.c b/client/assistant.c > index 77fb78329..16e94664a 100644 > --- a/client/assistant.c > +++ b/client/assistant.c > @@ -255,28 +255,32 @@ static void push_reply(DBusMessage *message, void *user_data) > static void assistant_set_bcode_cfg(const char *input, void *user_data) > { > struct assistant_config *cfg = user_data; > - char *endptr; > - uint8_t *bcode = cfg->qos.bcast.bcode; > > if (!strcasecmp(input, "a") || !strcasecmp(input, "auto")) { > - memset(bcode, 0, BCODE_LEN); > + memset(cfg->qos.bcast.bcode, 0, BCODE_LEN); > } else { > - bcode[0] = strtol(input, &endptr, 16); > + if (strlen(input) > BCODE_LEN) { > + bt_shell_printf("Input string too long %s\n", input); > + goto fail; > + } > > - for (uint8_t i = 1; i < BCODE_LEN; i++) > - bcode[i] = strtol(endptr, &endptr, 16); > + memcpy(cfg->qos.bcast.bcode, input, strlen(input)); > } > > if (!g_dbus_proxy_method_call(cfg->proxy, "Push", > push_setup, push_reply, > cfg, NULL)) { > bt_shell_printf("Failed to push assistant\n"); > + goto fail; > + } > > - free(cfg->meta); > - g_free(cfg); > + return; > > - return bt_shell_noninteractive_quit(EXIT_FAILURE); > - } > +fail: > + free(cfg->meta); > + g_free(cfg); > + > + return bt_shell_noninteractive_quit(EXIT_FAILURE); > } > > static void assistant_set_metadata_cfg(const char *input, void *user_data) > -- > 2.39.2 > -- Luiz Augusto von Dentz
