extmod/modbluetooth: Add support for passkey authentication.

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

3 files changed, 71 insertions, 0 deletions

diff --git a/extmod/modbluetooth.c b/extmod/modbluetooth.c
index ba5333e70..caaf872e7 100644
--- a/extmod/modbluetooth.c
+++ b/extmod/modbluetooth.c
@@ -689,6 +689,14 @@ STATIC mp_obj_t bluetooth_ble_gap_pair(mp_obj_t self_in, mp_obj_t conn_handle_in
     return bluetooth_handle_errno(mp_bluetooth_gap_pair(conn_handle));
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(bluetooth_ble_gap_pair_obj, bluetooth_ble_gap_pair);
+
+STATIC mp_obj_t bluetooth_ble_gap_passkey(size_t n_args, const mp_obj_t *args) {
+    uint16_t conn_handle = mp_obj_get_int(args[1]);
+    uint8_t action = mp_obj_get_int(args[2]);
+    mp_int_t passkey = mp_obj_get_int(args[3]);
+    return bluetooth_handle_errno(mp_bluetooth_gap_passkey(conn_handle, action, passkey));
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bluetooth_ble_gap_passkey_obj, 4, 4, bluetooth_ble_gap_passkey);
 #endif // MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
 
 // ----------------------------------------------------------------------------
@@ -894,6 +902,7 @@ STATIC const mp_rom_map_elem_t bluetooth_ble_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_gap_disconnect), MP_ROM_PTR(&bluetooth_ble_gap_disconnect_obj) },
     #if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
     { MP_ROM_QSTR(MP_QSTR_gap_pair), MP_ROM_PTR(&bluetooth_ble_gap_pair_obj) },
+    { MP_ROM_QSTR(MP_QSTR_gap_passkey), MP_ROM_PTR(&bluetooth_ble_gap_passkey_obj) },
     #endif
     // GATT Server (i.e. peripheral/advertiser role)
     { MP_ROM_QSTR(MP_QSTR_gatts_register_services), MP_ROM_PTR(&bluetooth_ble_gatts_register_services_obj) },
@@ -1167,6 +1176,11 @@ bool mp_bluetooth_gap_on_set_secret(uint8_t type, const uint8_t *key, size_t key
     mp_obj_t result = invoke_irq_handler(MP_BLUETOOTH_IRQ_SET_SECRET, args, 1, 0, NULL_ADDR, NULL_UUID, data, data_len, 2);
     return mp_obj_is_true(result);
 }
+
+void mp_bluetooth_gap_on_passkey_action(uint16_t conn_handle, uint8_t action, mp_int_t passkey) {
+    mp_int_t args[] = { conn_handle, action, passkey };
+    invoke_irq_handler(MP_BLUETOOTH_IRQ_PASSKEY_ACTION, args, 2, 1, NULL_ADDR, NULL_UUID, NULL_DATA, NULL_DATA_LEN, 0);
+}
 #endif // MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
 
 void mp_bluetooth_gatts_on_write(uint16_t conn_handle, uint16_t value_handle) {
diff --git a/extmod/modbluetooth.h b/extmod/modbluetooth.h
index d79b7f56b..f14033de3 100644
--- a/extmod/modbluetooth.h
+++ b/extmod/modbluetooth.h
@@ -148,6 +148,7 @@
 #define MP_BLUETOOTH_IRQ_ENCRYPTION_UPDATE              (28)
 #define MP_BLUETOOTH_IRQ_GET_SECRET                     (29)
 #define MP_BLUETOOTH_IRQ_SET_SECRET                     (30)
+#define MP_BLUETOOTH_IRQ_PASSKEY_ACTION                 (31)
 
 #define MP_BLUETOOTH_ADDRESS_MODE_PUBLIC (0)
 #define MP_BLUETOOTH_ADDRESS_MODE_RANDOM (1)
@@ -167,6 +168,12 @@
 #define MP_BLUETOOTH_PASSKEY_ACTION_DISPLAY             (3)
 #define MP_BLUETOOTH_PASSKEY_ACTION_NUMERIC_COMPARISON  (4)
 
+// These match NimBLE BLE_SM_IOACT_.
+#define MP_BLUETOOTH_PASSKEY_ACTION_NONE                (0)
+#define MP_BLUETOOTH_PASSKEY_ACTION_INPUT               (2)
+#define MP_BLUETOOTH_PASSKEY_ACTION_DISPLAY             (3)
+#define MP_BLUETOOTH_PASSKEY_ACTION_NUMERIC_COMPARISON  (4)
+
 /*
 These aren't included in the module for space reasons, but can be used
 in your Python code if necessary.
@@ -202,6 +209,7 @@ _IRQ_CONNECTION_UPDATE = const(27)
 _IRQ_ENCRYPTION_UPDATE = const(28)
 _IRQ_GET_SECRET = const(29)
 _IRQ_SET_SECRET = const(30)
+_IRQ_PASSKEY_ACTION = const(31)
 
 _FLAG_BROADCAST = const(0x0001)
 _FLAG_READ = const(0x0002)
@@ -231,6 +239,11 @@ _IO_CAPABILITY_DISPLAY_YESNO = const(1)
 _IO_CAPABILITY_KEYBOARD_ONLY = const(2)
 _IO_CAPABILITY_NO_INPUT_OUTPUT = const(3)
 _IO_CAPABILITY_KEYBOARD_DISPLAY = const(4)
+
+_PASSKEY_ACTION_NONE = const(0)
+_PASSKEY_ACTION_INPUT = const(2)
+_PASSKEY_ACTION_DISPLAY = const(3)
+_PASSKEY_ACTION_NUMERIC_COMPARISON = const(4)
 */
 
 // bluetooth.UUID type.
@@ -332,6 +345,9 @@ int mp_bluetooth_set_preferred_mtu(uint16_t mtu);
 #if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
 // Initiate pairing on the specified connection.
 int mp_bluetooth_gap_pair(uint16_t conn_handle);
+
+// Respond to a pairing request.
+int mp_bluetooth_gap_passkey(uint16_t conn_handle, uint8_t action, mp_int_t passkey);
 #endif // MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
 
 #if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
@@ -387,8 +403,12 @@ void mp_bluetooth_gatts_on_encryption_update(uint16_t conn_handle, bool encrypte
 // Call this when you need the application to manage persistent key data.
 // For get, if key is NULL, then the implementation must return the index'th matching key. Otherwise it should return a specific key.
 // For set, if value is NULL, then delete.
+// The "type" is stack-specific, but could also be used to implement versioning.
 bool mp_bluetooth_gap_on_get_secret(uint8_t type, uint8_t index, const uint8_t *key, size_t key_len, const uint8_t **value, size_t *value_len);
 bool mp_bluetooth_gap_on_set_secret(uint8_t type, const uint8_t *key, size_t key_len, const uint8_t *value, size_t value_len);
+
+// Call this when a passkey verification needs to be processed.
+void mp_bluetooth_gap_on_passkey_action(uint16_t conn_handle, uint8_t action, mp_int_t passkey);
 #endif // MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
 
 // Call this when a characteristic is written to.
diff --git a/extmod/nimble/modbluetooth_nimble.c b/extmod/nimble/modbluetooth_nimble.c
index 2b273c6bc..ae727086e 100644
--- a/extmod/nimble/modbluetooth_nimble.c
+++ b/extmod/nimble/modbluetooth_nimble.c
@@ -347,6 +347,16 @@ STATIC int gap_event_cb(struct ble_gap_event *event, void *arg) {
             return BLE_GAP_REPEAT_PAIRING_RETRY;
         }
 
+        case BLE_GAP_EVENT_PASSKEY_ACTION: {
+            DEBUG_printf("gap_event_cb: passkey action: conn_handle=%d action=%d num=" UINT_FMT "\n", event->passkey.conn_handle, event->passkey.params.action, (mp_uint_t)event->passkey.params.numcmp);
+
+            #if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
+            mp_bluetooth_gap_on_passkey_action(event->passkey.conn_handle, event->passkey.params.action, event->passkey.params.numcmp);
+            #endif
+
+            return 0;
+        }
+
         default:
             DEBUG_printf("gap_event_cb: unknown type %d\n", event->type);
             break;
@@ -886,6 +896,33 @@ int mp_bluetooth_gap_pair(uint16_t conn_handle) {
     DEBUG_printf("mp_bluetooth_gap_pair: conn_handle=%d\n", conn_handle);
     return ble_hs_err_to_errno(ble_gap_security_initiate(conn_handle));
 }
+
+int mp_bluetooth_gap_passkey(uint16_t conn_handle, uint8_t action, mp_int_t passkey) {
+    struct ble_sm_io io = {0};
+
+    switch (action) {
+        case MP_BLUETOOTH_PASSKEY_ACTION_INPUT: {
+            io.passkey = passkey;
+            break;
+        }
+        case MP_BLUETOOTH_PASSKEY_ACTION_DISPLAY: {
+            io.passkey = passkey;
+            break;
+        }
+        case MP_BLUETOOTH_PASSKEY_ACTION_NUMERIC_COMPARISON: {
+            io.numcmp_accept = passkey != 0;
+            break;
+        }
+        default: {
+            return MP_EINVAL;
+        }
+    }
+
+    io.action = action;
+
+    DEBUG_printf("mp_bluetooth_gap_passkey: injecting IO: conn_handle=%d, action=%d, passkey=" UINT_FMT ", numcmp_accept=%d\n", conn_handle, io.action, (mp_uint_t)io.passkey, io.numcmp_accept);
+    return ble_hs_err_to_errno(ble_sm_inject_io(conn_handle, &io));
+}
 #endif // MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
 
 #if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE