AVL AES Key Handling

sequenceDiagram

	participant Dev as "Device"
        participant Dev_TCP as "Device TCP Session"
        participant D2S_TCP as "D2Sphere TCP Session"
        participant D2S_DB as "D2Sphere Database"
        participant D2S_API as "D2SPhere REST API"
	 
	autonumber
	... create D2Sphere TCP conncetion ...
	Dev -> Dev_TCP : create TCP session
	Dev_TCP -> D2S_TCP : sent Login plain (contains uuid/IMEI and used enryption mode)
	Dev_TCP <- Dev : load AES key from TPM key store to AES module
	Dev_TCP <- Dev_TCP : start using enryption
	Dev_TCP <- Dev_TCP : parse Login, mode, uuid
	Dev_TCP <- D2S_DB : load AES key for uuid
	D2S_TCP <- D2S_TCP : start using enryption
	Dev_TCP <-> D2S_TCP : excahnge data
	Dev_TCP <-> D2S_TCP : excahnge data
	
	... key change via REST API ...
	Dev_TCP <-> D2S_TCP : excahnge data
	Dev_TCP <-> D2S_TCP : excahnge data
	D2S_TCP <- D2S_API: keychange request with new key
	Dev_TCP <- D2S_TCP : sent new Key
	Dev <- Dev_TCP : store new key in TPM key store
	D2S_TCP <- Dev_TCP : sent ACK / OK:ERROR
	Dev_TCP <- Dev_TCP : use new Key
	D2S_TCP <- D2S_TCP : receive ACK / OK
	D2S_DB <- D2S_TCP : store new Key
	D2S_TCP -> D2S_API : respond API request
	D2S_TCP <- D2S_TCP : use new key
	Dev_TCP <-> D2S_TCP : excahnge data with new Key
	Dev_TCP <-> D2S_TCP : excahnge data with new Key