# UI Web Socket Session Establishment

(1) Web client accesses index.html but is redirected to login page for
    basic authentication.

(2) `MainIndexResource` (protected page, user is now authenticated) requests
    a token to be generated by the `UiTokenService`.

(3) `UiTokenService` generates token, adds it to distributed map as
    entry `{token -> username}`, and returns token to `MainIndexResource`.

(4) `MainIndexResource` embeds username and token in `index.html`.

(5) Web client opens web socket connection (promoted from http). Note that
    the `UiWebSocket` instance is not marked as "authenticated" yet...


(6) `UiWebSocket` sends bootstrap data (list of ONOS cluster node IPs)

(7) Web client sends initial message "uiAuthenticate", along with username
    and authentication token (picked up from `index.html`).

(8) `UiWebsocket` verifies that token is valid via the `UiTokenService`, and
    marks itself as "authenticated".

(9) Subsequent `onMessage()` calls to `UiWebSocket` only proceed if 
    "authenticated" is true.

(10) User logs out of ONOS UI, generates onClose() call.

(11) `UiWebSocket` requests the token be revoked.

(12) `UiTokenService` unmaps the token from the distributed map.


```
 WebClient           MainIndex           UiToken           WebSocket
 ----+----           ----+----           ---+---           ----+----
     |            login* |                  |                  |    * basic
(1)  o------------------>|                  |                  |     auth'n 
     |                   |  issueToken(usr) |                  |
(2)  |                   o----------------->|                  |
     |                   |                  o- map token in    |
(3)  |                   | tkn              |  distrib. map    |
     | index.html(tkn)   |<-----------------o                  |
(4)  |<------------------o                  |                  |
     |                   |                  |           onOpen |
(5)  o-------------------------------------------------------->|
     | bootstrapData     |                  |                  |
(6)  |<--------------------------------------------------------o
     |                   |                  |                  |
     |                   |                  |   onMsg(usr,tkn) |
(7)  o-------------------------------------------------------->|
     |                   |                  | isValid(tkn)     |
(8)  |                   |                  |<-----------------o
     |                   |                  o----------------->| 
     |                   |                  |                  o- mark socket
     |                   |                  |                  |  valid
     |                   |                  |                  |
     |                   |                  |       onMsg(...) |
(9)  o-------------------------------------------------------->|
     |                   |                  |                  o- only processed
     |                   |                  |                  |  if socket valid
     
     :                   :                  :                  :
     
     |                   |                  |          onClose |
(10) o-------------------------------------------------------->|
     |                   |                  | revoke(tkn)      |
(11) |                   |                  |<-----------------o
(12) |                   |                  o- unmap token in  |
     |                   |                  |  distrib. map    |
     |                   |                  |                  |
```