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 ${url} with`)
  11   console.log(data)
  12   const request = new XMLHttpRequest()
  13   request.open('GET', url, true)
  14   request.setRequestHeader('Content-Type', 'application/json' )
  15   request.setRequestHeader('X-Strapp-Type', JSON.stringify(data))
  16   request.onreadystatechange = () => {
  17     if (request.status === 200) {
  18       console.log(request.response)
  19       resolve(request.response)
  20     }
  21     else if (request.status === 504) {
  22       console.log('timed out, resending')
  23       pollServerTimeout(url, data, resolve, reject)
  24     }
  25     else {
  26       reject('server unhandled response of status ' + request.status)
  27     }
  28   }
  29   console.log(data)
  30   request.send()
  31 }
  32
  33 /* TODO: All this does is wrap a function in a promise */
  34 function pollServer(url, clientPubKey, func) {
  35   return new Promise((resolve, reject) => {
  36     func(url, clientPubKey, resolve, reject )
  37   })
  38 }
  39
  40 /* TODO: duplicate in both client.js and host.js */
  41 function getPublicKey() {
  42   return new Promise( (resolve, reject) => {
  43     /* Check local storage for public key */
  44     if (!window.localStorage.getItem('public-key')) {
  45       console.log('public key is undefined')
  46       /* If doesn't exist, generate public and private key pair, store in
  47       local storage */
  48       crypto.subtle.generateKey(
  49         { name:'RSA-OAEP',
  50           modulusLength: 2048,
  51           publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
  52           hash: {name: "SHA-256"}
  53         },
  54         true,
  55         ['encrypt', 'decrypt']
  56         ).then((keyPair) => {
  57           /* TODO: Do we need to store the private key as well? */
  58           crypto.subtle.exportKey('jwk', keyPair.publicKey)
  59           .then((exportedKey) => {
  60             window.localStorage.setItem('publicKey', exportedKey)
  61             console.log('public key is' + window.localStorage.getItem('publicKey'))
  62             resolve(exportedKey)
  63           })
  64
  65         })
  66     }
  67     else {
  68       resolve(window.localStorage.getItem('publicKey'))
  69     }
  70   })
  71
  72 }
  73
  74 /* Create, set, and get client Offer. Poll server for host answer.
  75    Set host answer as client remoteDescription */
  76 const cpc = new RTCPeerConnection()
  77 console.log('creating offer')
  78 cpc.createOffer().then((offer) => {
  79   return cpc.setLocalDescription(offer)
  80 })
  81   .then(() => {
  82   console.log('sessionDescriptionInit = ' + cpc.localDescription)
  83   getPublicKey().then((cpk) => {
  84     console.log('cpk is' + cpk)
  85     let offer = {
  86       cmd: '> sdp pubKey',
  87       sdp: cpc.localDescription,
  88       pubKey: cpk
  89     }
  90     /* Poll for answer */
  91     return pollServer(window.location, offer, pollServerTimeout)
  92   }).then((answer) => {
  93     //console.log(answer)
  94     /* TODO: State machine to parse answer */
  95     cpc.setRemoteDescription(answer.sdp)
  96   }).catch( (err) => {
  97     console.log('error in sdp handshake: ' + err)
  98   })
  99 })
 100   .catch((err) => {
 101     console.log(err)
 102   })