From 7bdbe8291407ed22802b63707fbfe49d09651bf9 Mon Sep 17 00:00:00 2001
From: Lurkars <git@8lh.de>
Date: Sat, 11 Jul 2020 17:33:47 +0200
Subject: [PATCH] fixed scanning (forgot flag, dueto google not sending it)

---
 README.md                 |  6 ++++++
 main/ena-bluetooth-scan.c | 22 ++++++++++++++++++----
 main/ena.c                | 17 ++++++++---------
 main/main.c               | 15 ++++++++-------
 partitions.csv            |  2 +-
 5 files changed, 41 insertions(+), 21 deletions(-)

diff --git a/README.md b/README.md
index 0ee4ff4..84a1461 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,12 @@ recommended
 
 ### Build and Flash
 
+May flash partition table:
+
+```
+idf.py partition_table-flash
+```
+
 Build the project and flash it to the board, then run monitor tool to view serial output:
 
 ```
diff --git a/main/ena-bluetooth-scan.c b/main/ena-bluetooth-scan.c
index 35cf167..ff8f2e8 100644
--- a/main/ena-bluetooth-scan.c
+++ b/main/ena-bluetooth-scan.c
@@ -34,19 +34,33 @@ void ena_bluetooth_scan_event_callback(esp_gap_ble_cb_event_t event, esp_ble_gap
     case ESP_GAP_BLE_SCAN_RESULT_EVT:
         if (p->scan_rst.search_evt == ESP_GAP_SEARCH_INQ_RES_EVT)
         {
-            // check for ENA Service UUID:
-            if (p->scan_rst.ble_adv[0] == 0x3 && p->scan_rst.ble_adv[1] == 0x3 && p->scan_rst.ble_adv[2] == 0x6f && p->scan_rst.ble_adv[3] == 0xfd)
+            if (p->scan_rst.adv_data_len < 28)
+            {
+                // adv_data too short for exposure notification
+                break;
+            }
+
+            int flag_offset = 0;
+            // received payload from Google does not contain flag specified in Bluetooth Specification!? So check for length and then add offset
+            if (p->scan_rst.adv_data_len == 31)
+            {
+                // data contains flag
+                flag_offset = 3;
+            }
+
+            // check for ENA Service UUID: (after flag 0x03 0x03 0x6f 0xfd for ENA service)
+            if (p->scan_rst.ble_adv[0 + flag_offset] == 0x3 && p->scan_rst.ble_adv[1 + flag_offset] == 0x3 && p->scan_rst.ble_adv[2 + flag_offset] == 0x6f && p->scan_rst.ble_adv[3 + flag_offset] == 0xfd)
             {
                 uint8_t rpi[ENA_KEY_LENGTH] = {0};
                 for (int i = 0; i < ENA_KEY_LENGTH; i++)
                 {
-                    rpi[i] = p->scan_rst.ble_adv[8 + i];
+                    rpi[i] = p->scan_rst.ble_adv[i + 8 + flag_offset];
                 }
 
                 uint8_t aem[ENA_AEM_METADATA_LENGTH] = {0};
                 for (int i = 0; i < ENA_AEM_METADATA_LENGTH; i++)
                 {
-                    aem[i] = p->scan_rst.ble_adv[8 + ENA_KEY_LENGTH + i];
+                    aem[i] = p->scan_rst.ble_adv[i + ENA_KEY_LENGTH + 8 + flag_offset];
                 }
 
                 ena_detection((uint32_t)time(NULL), rpi, aem, p->scan_rst.rssi);
diff --git a/main/ena.c b/main/ena.c
index 113e160..65ba6e9 100644
--- a/main/ena.c
+++ b/main/ena.c
@@ -30,27 +30,26 @@ void ena_init(void)
         ESP_ERROR_CHECK(nvs_flash_erase());
         ESP_ERROR_CHECK(nvs_flash_init());
     }
-
     // init BLE
     esp_bt_controller_config_t bt_cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();
     ESP_ERROR_CHECK(esp_bt_controller_init(&bt_cfg));
     ESP_ERROR_CHECK(esp_bt_controller_enable(ESP_BT_MODE_BLE));
+
     ESP_ERROR_CHECK(esp_bluedroid_init());
     ESP_ERROR_CHECK(esp_bluedroid_enable());
 
+    // new bluetooth address nesseccary?
+    uint8_t bt_address[ESP_BD_ADDR_LEN];
+    esp_fill_random(bt_address, ESP_BD_ADDR_LEN);
+    bt_address[0] |= 0xC0;
+
+    ESP_ERROR_CHECK(esp_ble_gap_set_rand_addr(bt_address));
+
     ESP_ERROR_CHECK(esp_ble_tx_power_set(ESP_BLE_PWR_TYPE_DEFAULT, ESP_PWR_LVL_P9));
     ESP_ERROR_CHECK(esp_ble_tx_power_set(ESP_BLE_PWR_TYPE_ADV, ESP_PWR_LVL_P9));
     ESP_ERROR_CHECK(esp_ble_tx_power_set(ESP_BLE_PWR_TYPE_SCAN, ESP_PWR_LVL_P9));
     ESP_ERROR_CHECK(esp_ble_gap_config_local_privacy(true));
 
-    /* nesseccary?
-    // new bluetooth address
-    uint8_t bt_address[ESP_BD_ADDR_LEN];
-    esp_fill_random(bt_address, ESP_BD_ADDR_LEN);
-    bt_address[0] |= 0xC0;
-
-    ESP_ERROR_CHECK(esp_ble_gap_set_rand_addr(bt_address));
-*/
     // init ENA
     ena_crypto_init();
 
diff --git a/main/main.c b/main/main.c
index 4c57fac..2abf6be 100644
--- a/main/main.c
+++ b/main/main.c
@@ -1,14 +1,14 @@
 /**
  * provide bluetooth part of Exposure Notification API v1.2 as defined by Apple/Google
- * 
+ *
  * Source documents:
- * 
+ *
  * https://blog.google/documents/70/Exposure_Notification_-_Bluetooth_Specification_v1.2.2.pdf
- * 
+ *
  * https://covid19-static.cdn-apple.com/applications/covid19/current/static/detection-tracing/pdf/ExposureNotification-BluetoothSpecificationv1.2.pdf
- * 
- * 
- * 
+ *
+ *
+ *
  */
 
 #include <stdio.h>
@@ -31,7 +31,7 @@ void app_main(void)
     settimeofday(&tv, NULL);
 
     esp_log_level_set(ENA_STORAGE_LOG, ESP_LOG_INFO);
-    // ena_storage_erase();
+    ena_storage_erase(); // only needed on first start! TODO automatically check
 
     ena_init();
 
@@ -42,3 +42,4 @@ void app_main(void)
         vTaskDelay(1000 / portTICK_PERIOD_MS);
     }
 }
+
diff --git a/partitions.csv b/partitions.csv
index fc77773..b2d0479 100644
--- a/partitions.csv
+++ b/partitions.csv
@@ -3,4 +3,4 @@
 nvs,      data, nvs,     0x9000,  0x6000,
 phy_init, data, phy,     0xf000,  0x1000,
 factory,  app,  factory, 0x10000, 1M,
-ena,      data, nvs,     0x110000,0x2C0000,
\ No newline at end of file
+ena,      data, 0xFF,     0x110000,0x2C0000,
\ No newline at end of file