extmod/modbluetooth: Add _IRQ_ENCRYPTION_UPDATE event.

This allows the application to be notified if any of encrypted,
authenticated and bonded state change, as well as the encryption key size.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

docs/library/ubluetooth.rst

@@ -202,6 +202,9 @@ Event Handling
             elif event == _IRQ_CONNECTION_UPDATE:
                 # The remote device has updated connection parameters.
                 conn_handle, conn_interval, conn_latency, supervision_timeout, status = data
+            elif event == _IRQ_ENCRYPTION_UPDATE:
+                # The encryption state has changed (likely as a result of pairing or bonding).
+                conn_handle, encrypted, authenticated, bonded, key_size = data
 
 The event codes are::
 
@@ -233,6 +236,7 @@ The event codes are::
     _IRQ_L2CAP_RECV = const(25)
     _IRQ_L2CAP_SEND_READY = const(26)
     _IRQ_CONNECTION_UPDATE = const(27)
+    _IRQ_ENCRYPTION_UPDATE = const(28)
 
 For the ``_IRQ_GATTS_READ_REQUEST`` event, the available return codes are::
 

extmod/btstack/modbluetooth_btstack.c

@@ -359,6 +359,35 @@ STATIC void btstack_packet_handler(uint8_t packet_type, uint8_t *packet, uint8_t
         DEBUG_printf("  --> btstack # conns changed\n");
     } else if (event_type == HCI_EVENT_VENDOR_SPECIFIC) {
         DEBUG_printf("  --> hci vendor specific\n");
+    } else if (event_type == SM_EVENT_AUTHORIZATION_RESULT ||
+               event_type == SM_EVENT_PAIRING_COMPLETE ||
+               // event_type == GAP_EVENT_DEDICATED_BONDING_COMPLETED || // No conn_handle
+               event_type == HCI_EVENT_ENCRYPTION_CHANGE) {
+        DEBUG_printf("  --> enc/auth/pair/bond change\n", );
+        #if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
+        uint16_t conn_handle;
+        switch (event_type) {
+            case SM_EVENT_AUTHORIZATION_RESULT:
+                conn_handle = sm_event_authorization_result_get_handle(packet);
+                break;
+            case SM_EVENT_PAIRING_COMPLETE:
+                conn_handle = sm_event_pairing_complete_get_handle(packet);
+                break;
+            case HCI_EVENT_ENCRYPTION_CHANGE:
+                conn_handle = hci_event_encryption_change_get_connection_handle(packet);
+                break;
+            default:
+                return;
+        }
+
+        hci_connection_t *hci_con = hci_connection_for_handle(conn_handle);
+        sm_connection_t *desc = &hci_con->sm_connection;
+        mp_bluetooth_gatts_on_encryption_update(conn_handle,
+            desc->sm_connection_encrypted,
+            desc->sm_connection_authenticated,
+            desc->sm_le_db_index != -1,
+            desc->sm_actual_encryption_key_size);
+        #endif // MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
     } else if (event_type == HCI_EVENT_DISCONNECTION_COMPLETE) {
         DEBUG_printf("  --> hci disconnect complete\n");
         uint16_t conn_handle = hci_event_disconnection_complete_get_connection_handle(packet);

extmod/modbluetooth.c

@@ -1107,6 +1107,13 @@ void mp_bluetooth_gap_on_connection_update(uint16_t conn_handle, uint16_t conn_i
     invoke_irq_handler(MP_BLUETOOTH_IRQ_CONNECTION_UPDATE, args, 5, NULL_U8, 0, NULL_ADDR, NULL_I8, 0, NULL_UUID, NULL_DATA, 0);
 }
 
+#if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
+void mp_bluetooth_gatts_on_encryption_update(uint16_t conn_handle, bool encrypted, bool authenticated, bool bonded, uint8_t key_size) {
+    uint8_t args[] = {encrypted, authenticated, bonded, key_size};
+    invoke_irq_handler(MP_BLUETOOTH_IRQ_ENCRYPTION_UPDATE, &conn_handle, 1, args, 4, NULL_ADDR, NULL_I8, 0, NULL_UUID, NULL_DATA, 0);
+}
+#endif // MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
+
 void mp_bluetooth_gatts_on_write(uint16_t conn_handle, uint16_t value_handle) {
     uint16_t args[] = {conn_handle, value_handle};
     invoke_irq_handler(MP_BLUETOOTH_IRQ_GATTS_WRITE, args, 2, NULL_U8, 0, NULL_ADDR, NULL_I8, 0, NULL_UUID, NULL_DATA, 0);

extmod/modbluetooth.h

@@ -145,6 +145,7 @@
 #define MP_BLUETOOTH_IRQ_L2CAP_RECV                     (25)
 #define MP_BLUETOOTH_IRQ_L2CAP_SEND_READY               (26)
 #define MP_BLUETOOTH_IRQ_CONNECTION_UPDATE              (27)
+#define MP_BLUETOOTH_IRQ_ENCRYPTION_UPDATE              (28)
 
 #define MP_BLUETOOTH_ADDRESS_MODE_PUBLIC (0)
 #define MP_BLUETOOTH_ADDRESS_MODE_RANDOM (1)
@@ -182,7 +183,8 @@ _IRQ_L2CAP_CONNECT = const(23)
 _IRQ_L2CAP_DISCONNECT = const(24)
 _IRQ_L2CAP_RECV = const(25)
 _IRQ_L2CAP_SEND_READY = const(26)
-_IRQ_GATTS_CONN_UPDATE = const(27)
+_IRQ_CONNECTION_UPDATE = const(27)
+_IRQ_ENCRYPTION_UPDATE = const(28)
 
 _FLAG_BROADCAST = const(0x0001)
 _FLAG_READ = const(0x0002)
@@ -339,6 +341,11 @@ void mp_bluetooth_gap_on_connected_disconnected(uint8_t event, uint16_t conn_han
 // Call this when any connection parameters have been changed.
 void mp_bluetooth_gap_on_connection_update(uint16_t conn_handle, uint16_t conn_interval, uint16_t conn_latency, uint16_t supervision_timeout, uint16_t status);
 
+#if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
+// Call this when any connection encryption has been changed (e.g. during pairing).
+void mp_bluetooth_gatts_on_encryption_update(uint16_t conn_handle, bool encrypted, bool authenticated, bool bonded, uint8_t key_size);
+#endif
+
 // Call this when a characteristic is written to.
 void mp_bluetooth_gatts_on_write(uint16_t conn_handle, uint16_t value_handle);
 

extmod/nimble/modbluetooth_nimble.c

@@ -316,6 +316,19 @@ STATIC int gap_event_cb(struct ble_gap_event *event, void *arg) {
             }
             break;
         }
+
+        case BLE_GAP_EVENT_ENC_CHANGE: {
+            DEBUG_printf("gap_event_cb: enc change: status=%d\n", event->enc_change.status);
+            #if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
+            struct ble_gap_conn_desc desc;
+            if (ble_gap_conn_find(event->enc_change.conn_handle, &desc) == 0) {
+                mp_bluetooth_gatts_on_encryption_update(event->conn_update.conn_handle,
+                    desc.sec_state.encrypted, desc.sec_state.authenticated,
+                    desc.sec_state.bonded, desc.sec_state.key_size);
+            }
+            #endif
+            break;
+        }
     }
     return 0;
 }
@@ -971,6 +984,17 @@ STATIC int peripheral_gap_event_cb(struct ble_gap_event *event, void *arg) {
             break;
         }
 
+        case BLE_GAP_EVENT_ENC_CHANGE: {
+            DEBUG_printf("peripheral_gap_event_cb: enc change: status=%d\n", event->enc_change.status);
+            #if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
+            if (ble_gap_conn_find(event->enc_change.conn_handle, &desc) == 0) {
+                mp_bluetooth_gatts_on_encryption_update(event->conn_update.conn_handle,
+                    desc.sec_state.encrypted, desc.sec_state.authenticated,
+                    desc.sec_state.bonded, desc.sec_state.key_size);
+            }
+            #endif
+            break;
+        }
         default:
             break;
     }