performing complex handshake in ble_client on_connect

[kernel-io]

Describe your request

I've got a Dyson Solarcycle lamp which I was trying to control with ESPHome, that led to a rabbit hole where I ended up figuring out that there is an auth handshake which you need to perform before the lamp responds to your commands.

The process is basically

1. generate a derived key based on some static variables.
2. send a bunch of bluetooth messages (chunked because the lamp only accepts 20bytes at a time)
3. receive a response, decrypt it, reencrypt it using the derived key
4. send another bunch of messages to the lamp
5. lamp is ready to use.

Why the uncertainty?

No response

Use cases

I would like to figure out if it's possible / where I would add a multi-step handshake on_connect which uses AES CBC, and HKDF to generate auth keys for the lamp to respond. I'd love to see if anyone has any pointers or examples and has done this before.

What areas might this affect?

No response

Anything else?

No response