design2.txt

Node multi-plexes packets to the proper channel.

Each node maintains a set of endpoints.


Endpoint
  ip
  port
  dh_pub
  dh_shared
  blowfish
  id
  map<src_dst,channel> 
  state


Endpoint can be in the following states:

 [0 uninit ] 
    - On Remote DH key (non multiple of 8 message, > 56 bytes)
      - Create DH public key, send it.
      - Goto Known Remote DH Key
    - Anything else
      - Generate Local DH Key
      - Send DH key
      - goto [1]

 [1 Generated Local DH Key]
    - On Remote DH key (non multiple of 8 message, > 56 bytes)
      - Update blowfish
      - Send DH public key
      - Send Auth
      - Goto 2
    - Anything else
      - Send DH key

 [2 Known Remote DH Key]
    - On Remote DH key
      - Update blowfish
      - Send DH public key
      - Send Auth   
    - On Auth 
        - validate
        - update id to ep index
        - send auth response
        - goto 3, authenticated

 [3 Authenticated Identity]
    - On Auth
        - validate
        - if id changed... update id to ep index
        - send auth response
    - On DH Key
        - remove id to ep index (closing all channels)
        - Create DH pub
        - Send DH pub key
        - Send Auth
        - Goto 2 Known Remote DH Key
    - On Decrypt Failure
        - remove id to ep index (closing all channels)
        - Create DH pub key
        - Send DH pub key
        - Goto 1

 [4 Peer Authenticated Our Identity]
    - On Auth
        - validate
        - if id changed... update id to ep index
        - send auth response
    - On DH Key
        - remove id to ep index (closing all channels)
        - Create DH pub
        - Send DH pub key
        - Send Auth
        - Goto 2 Known Remote DH Key
    - On Decrypt Failure
        - remove id to ep index (closing all channels)
        - Create DH pub key
        - Send DH pub key
        - Goto 1

  At all times both clients attempt to