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 /* Poll the server. Send get request, wait for timeout, send another request.
   8    Do this until...? Can be used for either reconnecting or waiting for answer*/
   9 function pollServerTimeout(url, data, resolve, reject) {
  10   console.log('Polling server with offer ' + data)
  11   const request = new XMLHttpRequest()
  12   request.open('GET', url)
  13   request.setRequestHeader('Content-Type', 'application/json' )
  14   request.setRequestHeader('X-Strapp-Type', 'o' )
  15   request.onreadystatechange = () => {
  16     if (request.status === 200) {
  17       console.log(request.response)
  18       resolve(request.response)
  19     }
  20     else if (request.status === 504) {
  21       console.log('timed out, resending')
  22       pollServerTimeout(url, data, resolve, reject)
  23     }
  24     else {
  25       reject('server unhandled response of status ' + request.status)
  26     }
  27   }
  28   console.log(data)
  29   request.send('data in stufff and stuff in data')
  30 }
  31
  32 /* TODO: All this does is wrap a function in a promise */
  33 function pollServer(url, clientPubKey, func) {
  34   return new Promise((resolve, reject) => {
  35     func(url, clientPubKey, resolve, reject )
  36   })
  37 }
  38
  39 /* TODO: duplicate in both client.js and host.js */
  40 function getPublicKey() {
  41   return new Promise( (resolve, reject) => {
  42     /* Check local storage for public key */
  43     if (!window.localStorage.getItem('public-key')) {
  44       console.log('public key is undefined')
  45       /* If doesn't exist, generate public and private key pair, store in
  46       local storage */
  47       crypto.subtle.generateKey(
  48         { name:'RSA-OAEP',
  49           modulusLength: 2048,
  50           publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
  51           hash: {name: "SHA-256"}
  52         },
  53         true,
  54         ['encrypt', 'decrypt']
  55         ).then((keyPair) => {
  56           /* TODO: Do we need to store the private key as well? */
  57           crypto.subtle.exportKey('jwk', keyPair.publicKey)
  58           .then((exportedKey) => {
  59             window.localStorage.setItem('publicKey', exportedKey)
  60             console.log('public key is' + window.localStorage.getItem('publicKey'))
  61             resolve(exportedKey)
  62           })
  63
  64         })
  65     }
  66     else {
  67       resolve(window.localStorage.getItem('publicKey'))
  68     }
  69   })
  70
  71 }
  72
  73 /* Create, set, and get client Offer. Poll server for host answer.
  74    Set host answer as client remoteDescription */
  75 const cpc = new RTCPeerConnection()
  76 console.log('creating offer')
  77 cpc.createOffer().then((offer) => {
  78   return cpc.setLocalDescription(offer)
  79 }).then(() => {
  80   console.log('sessionDescriptionInit = ' + cpc.localDescription)
  81   getPublicKey().then((cpk) => {
  82     console.log('cpk is' + cpk)
  83     let offer = {
  84       cmd: '> sdp pubKey',
  85       sdp: cpc.localDescription,
  86       pubKey: cpk
  87     }
  88     /* Poll for answer */
  89     return pollServer(window.location, offer, pollServerTimeout)
  90   }).then((answer) => {
  91     //console.log(answer)
  92     /* TODO: State machine to parse answer */
  93     cpc.setRemoteDescription(answer.sdp)
  94   }).catch( (err) => {
  95     console.log('error in sdp handshake: ' + err)
  96   })
  97 })