Bluetooth: keys: Extend keys flags with OOB flag

Adds flag indicating the pairing that was completed using OOB method.
The flag is needed for checking 128bit entropy pairing required by LE
Audio services.

Signed-off-by: Mariusz Skamra <mariusz.skamra@codecoup.pl>

subsys/bluetooth/host/keys.h

@@ -30,6 +30,7 @@ enum {
 	BT_KEYS_DEBUG           = BIT(1),
 	/* Bit 2 and 3 might accidentally exist in old stored keys */
 	BT_KEYS_SC              = BIT(4),
+	BT_KEYS_OOB             = BIT(5),
 };
 
 struct bt_ltk {

subsys/bluetooth/host/smp.c

@@ -5803,16 +5803,19 @@ void bt_smp_update_keys(struct bt_conn *conn)
 	 * security level upon encryption
 	 */
 	switch (smp->method) {
+	case LE_SC_OOB:
+	case LEGACY_OOB:
+		conn->le.keys->flags |= BT_KEYS_OOB;
+		/* fallthrough */
 	case PASSKEY_DISPLAY:
 	case PASSKEY_INPUT:
 	case PASSKEY_CONFIRM:
-	case LE_SC_OOB:
-	case LEGACY_OOB:
 		conn->le.keys->flags |= BT_KEYS_AUTHENTICATED;
 		break;
 	case JUST_WORKS:
 	default:
 		/* unauthenticated key, clear it */
+		conn->le.keys->flags &= ~BT_KEYS_OOB;
 		conn->le.keys->flags &= ~BT_KEYS_AUTHENTICATED;
 		break;
 	}