Add data encryption support according to the bthome protocol

[junchao98]

hello everyone,

This submission I tested normal in the following cases

1. Encryption of individual sensor data
2. Encrypting multiple sensor data
3. No encryption

[stumpylog]

Awesome, thanks for the contribution. I'll have to pull my sensor package out of its case to test this, so it may take a few more days before I can merge it.

Just glancing through, it makes sense. I do see what looks like some formatting diffs. Could you run the clang formatter (there's format.sh for it)? Thanks!

[Chreece]

@junchao98 if you have time could you port your code to the general ESP32 example to finally have one with encryption?
https://github.com/Chreece/BTHomeV2-ESP32-example
(my programming skills are unfortunately basic)

[junchao98]

@junchao98 if you have time could you port your code to the general ESP32 example to finally have one with encryption? https://github.com/Chreece/BTHomeV2-ESP32-example (my programming skills are unfortunately basic)

No problem, I will submit the code in the near future

[countrysideboy]

@junchao98 if you have time could you port your code to the general ESP32 example to finally have one with encryption? https://github.com/Chreece/BTHomeV2-ESP32-example (my programming skills are unfortunately basic)

No problem, I will submit the code in the near future

Great! Thanks.

[stumpylog]

Testing this change out, I get an abort here:

ESP_ERROR_CHECK failed: esp_err_t 0x102 (ESP_ERR_INVALID_ARG) at 0x40090fb8
file: "./main/task_ble.cpp" line 112
func: void task_ble_entry(void*)
expression: esp_ble_gap_config_adv_data_raw(&advertData[0], dataLength)

Presumably, this is due to the advertisement being 35 bytes, more than the 31 allowed. It should probably check that and warn at least before aborting.

Edit: In fact, it would probably be good to support encryption, but no name, as the encryption adds so many extra bytes

[stumpylog]

Once I changed up the naming to be short enough (exactly 31 bytes), Home Assistant did pick it up as encryption and the bind key worked.

Just a small tweak to try and make it a little more friendly of an error I think, and I can merge it in

[junchao98]

Once I changed up the naming to be short enough (exactly 31 bytes), Home Assistant did pick it up as encryption and the bind key worked.

Just a small tweak to try and make it a little more friendly of an error I think, and I can merge it in

Yes, the esp-idf api has a requirement for maximum data length.

[stumpylog]

I know this looks closed, that's what I get for trying to manage too many remotes. I tweaked the changes a little so it won't abort if too long, and merged in the commits.

[countrysideboy]

@junchao98 if you have time could you port your code to the general ESP32 example to finally have one with encryption? https://github.com/Chreece/BTHomeV2-ESP32-example (my programming skills are unfortunately basic)

No problem, I will submit the code in the near future

I have ported your code to the BTHomeV2-ESP32-example project, thanks for your hard working.