host.js

   1 document.title = "Strapp.io Host"
   2 const conf = {"iceServers": [{ "urls": "stun:stun.1.google.com:19302" }] }
   3 const clients = new Map([])
   4 const iceCandidates = []
   5 let dataChannel
   6
   7
   8 /* TODO: duplicate in both client.js and host.jhs */
   9 function getPublicKey() {
  10   return new Promise( (resolve, reject) => {
  11     /* Check local storage for public key */
  12     if (!window.localStorage.getItem('public-key')) {
  13       console.log('public key is undefined')
  14       /* If doesn't exist, generate public and private key pair, store in
  15       local storage */
  16       crypto.subtle.generateKey(
  17         { name:'RSA-OAEP',
  18         modulusLength: 2048,
  19         publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
  20         hash: {name: "SHA-256"}
  21       },
  22       true,
  23       ['encrypt', 'decrypt']
  24     ).then((keyPair) => {
  25       /* TODO: Do we need to store the private key as well? */
  26       crypto.subtle.exportKey('jwk', keyPair.publicKey)
  27       .then((exportedKey) => {
  28         window.localStorage.setItem('publicKey', exportedKey)
  29         console.log('public key is' + window.localStorage.getItem('publicKey'))
  30         resolve(exportedKey)
  31       })
  32
  33     })
  34   }
  35   else {
  36     resolve(window.localStorage.getItem('publicKey'))
  37     }
  38   })
  39 }
  40
  41 function handleNewClientConnection(offer) {
  42   /* New Client Connection*/
  43   hpc = new RTCPeerConnection(conf)
  44   //console.log(offer)
  45   clients.set(offer.pubKey, hpc)
  46   hpc.setRemoteDescription(offer.sdp)
  47   .then(() => {
  48     hpc.createAnswer().then((answer) => {
  49       return hpc.setLocalDescription(answer)
  50     })
  51     .then(() => {
  52       getPublicKey().then((hpk) => {
  53         hpc.onicecandidate = (event) => {
  54           if (event.candidate) {
  55             console.log('Host: Allocating ice candidate for client')
  56             iceCandidates.push(JSON.stringify({
  57               cmd: "< ice pubKey",
  58               ice: event.candidate,
  59               hostPubKey: hpk.n, /* TODO: do we need to send this? */
  60               clientPubKey: offer.pubKey,
  61               iceState: "a"
  62             }))
  63           }
  64           else {
  65             console.log('Host: Finished sending ICE candidates')
  66             console.log(hpc)
  67           }
  68         }
  69         console.log('Host: Sending answer to Client')
  70         wsock.send(JSON.stringify({
  71           cmd: '< sdp pubKey',
  72           sdp: hpc.localDescription,
  73           hostPubKey: hpk.n,
  74           clientPubKey: offer.pubKey
  75         }))
  76         hpc.ondatachannel = (evt) => {
  77           dataChannel = evt.channel
  78           console.log(evt)
  79           dataChannel.onmessage = (msg) => {
  80             console.log(msg.data)
  81           }
  82           dataChannel.onopen = () => {
  83             dataChannel.send(`Hi ${offer.pubKey} -host`)
  84           }
  85         }
  86         hpc.oniceconnectionstatechange = () => {
  87           console.log('iceConnectionState = ' + hpc.iceConnectionState)
  88         }
  89       })
  90     }).catch((err) => {
  91       console.log(`error in host answer ${err}`)
  92     })
  93   })
  94
  95 }
  96
  97 function handleNewIceSubmission(msg) {
  98   console.log('Host: Adding new ice candidate')
  99   const hpc = clients.get(msg.pubKey)
 100   let candidate = new RTCIceCandidate(msg.ice)
 101   hpc.addIceCandidate(candidate)
 102 }
 103
 104 function handleIceRequest(msg) {
 105   console.log('Host: Handling ice candidate request')
 106   console.log(iceCandidates)
 107   const hpc = clients.get(msg.pubKey)
 108   const iceCandidate = iceCandidates.pop()
 109   if (iceCandidate !== undefined) {
 110     wsock.send(iceCandidate)
 111   } else {
 112     if (hpc.iceGatheringState.localeCompare('gathering') === 0) {
 113       wsock.send(`{"cmd" : "< ice pubKey", "clientPubKey":"${msg.pubKey}", "iceState": "g"}`)
 114     }
 115     else if (hpc.iceGatheringState.localeCompare('complete') === 0) {
 116       wsock.send(`{"cmd" : "< ice pubKey", "clientPubKey":"${msg.pubKey}", "iceState": "c"}`)
 117     }
 118
 119   }
 120
 121 }
 122 if ("WebSocket" in window) {
 123   document.addEventListener('DOMContentLoaded', (event) => {
 124     wsock = new WebSocket(`${_strapp_protocol}://${window.location.hostname}:${_strapp_port}`)
 125     wsock.onopen = () => {
 126       console.log(`Strapped to ${_strapp_protocol}://${window.location.hostname}:${_strapp_port}`)
 127     }
 128
 129     wsock.onmessage = (serverMsg) => {
 130       /* msg is either offer or ice candidate or ice candidate request*/
 131
 132       /* What if data null? */
 133       let msg = JSON.parse(serverMsg.data)
 134
 135       const clientID = msg.pubKey
 136
 137       /* TODO: redo this trash */
 138       if (clients.has(clientID)) {
 139         if (msg.ice) {
 140           handleNewIceSubmission(msg)
 141         } else if (msg.sdp) {
 142           //handleRepeatedOffer
 143         } else {
 144           handleIceRequest(msg)
 145         }
 146       }
 147       else {
 148         if (msg.ice) {
 149           console.log('Host: Client that doesnt exist is sending ice submissions')
 150         } else if (msg.sdp) {
 151           handleNewClientConnection(msg)
 152         } else {
 153           console.log('Host: Client that doesnt exist is sending ice requests')
 154         }
 155       }
 156     }
 157   })
 158 }
 159 else {
 160   document.addEventListener('DOMContentLoaded', () => {
 161     document.body.innerHTML = 'Websockets not supported in your browser'
 162   })
 163 }