MS-CDP: Connected Devices Platform Protocol
doc
MS-CDP: Connected Devices Platform Protocol Version 3
协议相对简单
connect
兼容：UDP/TCP/Cloud/BLE/RFcomm/Wifi Direct
UDP: device name, device id salt 4-byte, device id hash 4-byte
BLE: salt 4-byte, device hash 24-byte, BLE发现可能是broadcast/multicast
auth
Device Auth: self-signed, system boot时生成 => interesting
User Device Auth，system sign-in时生成 => 放哪呢？！
encryption
clientNonce (64-bit), serverNonce(64-bit)
ecdh 后 hkdf 生成 key (16-byte), iv (16-byte), hmac-key (32-byte)
