Create support for knx-ip secure

[thelsing]

No description provided.

[nanosonde]

Crypto stuff required:

• AES CBC MAC (already there due to data secure)
• PBKDF2-HMAC-SHA256: candidate: https://github.com/monolifed/pbkdf2-hmac-sha256/
• Elliptic curve 25519

[nanosonde]

Two existing implementations:

JS: https://github.com/Supergiovane/node-red-contrib-knx-ultimate/blob/master/KNXEngine/protocol/KNXSecureSessionRequest.js

JAVA: https://github.com/calimero-project/calimero-core/blob/master/src/tuwien/auto/calimero/knxnetip/SecureSessionUdp.java

[nanosonde]

Another implementation in Python: https://github.com/XKNX/xknx/pull/875/files

[farmio]

Hi 👋!
Since there is no support for Tunnelling at all currently, you may be more interested in Secure Routing. You can find a Python implementation here: https://github.com/XKNX/xknx/blob/5fa7f8b8712ef3c9631fc2617fa0a0996bf9656c/xknx/io/ip_secure.py#L388
This doesn't need Elliptic curve or PBKDF2-HMAC-SHA256 iirc 😃

Note: In xknx we don't expect to have a way to permanently store data, so we refrained from storing the latest timer value and just synchronise to other devices on startup.

[nanosonde]

xknx now has data secure support: https://github.com/XKNX/xknx/blob/main/xknx/secure/data_secure.py