Is the ESP32-S3 cannot support adding random IP addresses from Android phones to the whitelist?

[LusterWong]

Thank you for providing such a powerful library.

I am currently using the ESP32-S3 as a GATT server. I need to limit the connection to a maximum of two specific clients to prevent unauthorized access. My current approach is as follows:

In the onAuthenticationComplete callback, I use NimBLEDevice::whiteListAdd(connInfo.getAddress()) to add the Android phone's address to the whitelist.

Once two phones have been bonded, I enable whitelist filtering for advertising.

The Problem:
After an Android phone disconnects and attempts to reconnect, it fails to establish a connection indefinitely. Does NimBLE support the resolution of Random Addresses?

I am using the latest library version v2.3.9. How can I properly restrict clients when they use Random Resolvable Addresses?

NimBLEDevice::whiteListAdd(connInfo.getAddress());
NimBLEDevice::whiteListAdd(connInfo.getIdAddress());
bool bonded = connInfo.isBonded();
int bonds = NimBLEDevice::getNumBonds();

if(bonds >= MAX_BONDS) {
      NimBLEAdvertising* pAdvertising = NimBLEDevice::getAdvertising();
      pAdvertising->stop();
      pAdvertising->setScanFilter(true, true);
      pAdvertising->start();
      return;
      }

Furthermore, if the whitelist function fails to work, I think it is also possible to determine in the onConnect callback function whether the device making this connection has been bound. Unfortunately, in the onConnect function, for Android phones, connInfo.isBonded() is always equal to false. Only in the onAuthenticationComplete callback function does connInfo.isBonded() have an effect, but the timing for the judgment has been missed.

Thanks.

[h2zero]

Hi @LusterWong, the S3 certainly can do this. I must apologize for the lack of documentation regarding the process as this is quite a common requirement without a simple solution.

• The onConnect callback works the same here as on android, it doesn't know the state of bonding/authentication at this time. I suggest calling NimBLEDevice::startSecurity here and waiting for the onAuthenticationComplete callback.
• Then check the bonded status there and handle it accordingly.
• Next the onIdentity callback will be called which will provide the resolved ID address in NimBLEConnInfo::getIdAddress and this is what you need to use in the whitelist.

[LusterWong]

Hi @LusterWong, the S3 certainly can do this. I must apologize for the lack of documentation regarding the process as this is quite a common requirement without a simple solution.

• The onConnect callback works the same here as on android, it doesn't know the state of bonding/authentication at this time. I suggest calling NimBLEDevice::startSecurity here and waiting for the onAuthenticationComplete callback.
• Then check the bonded status there and handle it accordingly.
• Next the onIdentity callback will be called which will provide the resolved ID address in NimBLEConnInfo::getIdAddress and this is what you need to use in the whitelist.

Thanks for the reply. I previously tried using NimBLEDevice::whiteListAdd(connInfo.getAddress()); within the onAuthenticationComplete or onIdentity callbacks to whitelist the address. However, the Android phone would fail to reconnect after being disconnected for a while.

I’ll try using NimBLEConnInfo::getIdAddress() as you suggested to see if that achieves the goal.