client.js

   1 const body = document.createElement('body')
   2 const root = document.createElement('div')
   3 document.title = "Strapp.io Client"
   4 body.appendChild(root)
   5 document.body = body
   6
   7 /*************/
   8 /* UNTESTED */
   9 /************
  10
  11
  12 /* Poll the server. Send get request, wait for timeout, send another request.
  13    Do this until...? Can be used for either reconnecting or waiting for answer*/
  14 function pollServerTimeout(url, data, resolve, reject) {
  15   console.log('Polling server with offer ' + data)
  16   const request = XMLHttpRequest()
  17   request.open('GET', url)
  18   request.setRequestHeader('Content-Type', 'application/json' )
  19   request.onreadystatechange = () => {
  20     if (request.status === 200) {
  21       console.log('recieved answer from host ' + request.response)
  22       resolve(request.response)
  23     }
  24     else if (request.status === 504) {
  25       pollServerTimeout(url, data, resolve, reject)
  26     }
  27     else {
  28       reject('server errored out with ' + request.status)
  29     }
  30   }
  31   request.send(data)
  32 }
  33
  34 /* TODO: Possible to pass resolve/reject to functions? */
  35 function pollServer(url, clientPubKey, func) {
  36   return new Promise((resolve, reject) => {
  37     func(url, clientPubKey, resolve, reject )
  38   })
  39 }
  40 /* If https connection, should be already defined. If not https,*/
  41 function getPublicKey() {
  42   /* Check local storage for public key */
  43   if (window.localStorage.getItem('public-key') === undefined) {
  44     /* If doesn't exist, generate public and private key pair, store in
  45     local storage */
  46     crypto.subtle.generateKey({name:'RSA-OAEP', length: 192}, true, ['encrypt', 'decrypt'])
  47       .then((keyPair) => {
  48         /* TODO: Do we need to store the private key as well? */
  49         window.localStorage.setItem('public-key', keyPair.type.public.toString())
  50       })
  51   }
  52     console.log(window.localStorage.getItem('public-key'))
  53     return window.localStorage.getItem('public-key')
  54 }
  55
  56 /* Create, set, and get client Offer. Poll server for host answer.
  57    Set host answer as client remoteDescription */
  58 const cpc = new RTCPeerConnection()
  59 cpc.createOffer().then((offer) => {
  60   console.log('creating offer which is ' + offer)
  61   return cpc.setLocalDescription(offer)
  62 }).then(() => {
  63   console.log('sessionDescriptionInit = ' + cpc.localDescription)
  64   const cpk = getPublicKey()
  65   let offer = {
  66     cmd: '> sdp pubKey'
  67     sdp: cpc.localDescription,
  68     pubKey: cpk
  69   }
  70   /* Poll for answer */
  71   return pollServer(window.location, offer, pollServerTimeout)
  72 }).then((answer) => {
  73   /* TODO: Extract sdp from answer ?*/
  74   console.log(answer)
  75   /* State machine to parse answer */
  76   cpc.setRemoteDescription(answer.sdp)
  77 })