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             iceCandidates.push(JSON.stringify({
  56               cmd: '< ice pubKey',
  57               ice: event.candidate,
  58               hostPubKey: hpk.n, /* TODO: do we need to send this? */
  59               clientPubKey: offer.pubKey,
  60               iceCandidateAvailable: true
  61             }))
  62           }
  63           else {
  64             console.log('Host: Finished sending ICE candidates')
  65           }
  66         }
  67         console.log('Host: Sending answer to Client')
  68         wsock.send(JSON.stringify({
  69           cmd: '< sdp pubKey',
  70           sdp: hpc.localDescription,
  71           hostPubKey: hpk.n,
  72           clientPubKey: offer.pubKey
  73         }))
  74         hpc.ondatachannel = (evt) => {
  75           dataChannel = evt.channel
  76           console.log(evt)
  77           dataChannel.onmessage = (msg) => {
  78             console.log(msg.data)
  79           }
  80           dataChannel.send('Hi from the host')
  81         }
  82         hpc.oniceconnectionstatechange = () => {
  83           console.log('iceConnectionState = ' + hpc.iceConnectionState)
  84         }
  85       })
  86     }).catch((err) => {
  87       console.log(`error in host answer ${err}`)
  88     })
  89   })
  90
  91
  92
  93 }
  94
  95 function handleNewIceSubmission(msg) {
  96   console.log('Host: Adding new ice candidate')
  97   const hpc = clients.get(msg.pubKey)
  98   let candidate = new RTCIceCandidate(msg.ice)
  99   hpc.addIceCandidate(candidate)
 100 }
 101
 102 function handleIceRequest(msg) {
 103   console.log('Host: Sending ice candidate to client')
 104   const hpc = clients.get(msg)
 105   const iceCandidates = iceCandidates.pop()
 106   if (iceCandidate !== undefined) {
 107     wsock.send(iceCandidate)
 108   } else {
 109     wsock.send('no ice candidates')
 110   }
 111
 112 }
 113 if ("WebSocket" in window) {
 114   document.addEventListener('DOMContentLoaded', (event) => {
 115     wsock = new WebSocket(`${_strapp_protocol}://${window.location.hostname}:${_strapp_port}`)
 116     wsock.onopen = () => {
 117       console.log(`Strapped to ${_strapp_protocol}://${window.location.hostname}:${_strapp_port}`)
 118     }
 119
 120     wsock.onmessage = (serverMsg) => {
 121       /* msg is either offer or ice candidate or ice candidate request*/
 122
 123
 124       let msg = JSON.parse(serverMsg.data)
 125
 126       const clientID = msg.pubKey || msg
 127
 128       /* TODO: redo this trash */
 129       if (clients.has(clientID)) {
 130         if (msg.ice) {
 131           handleNewIceSubmission(msg)
 132         } else if (msg.sdp) {
 133           //handleRepeatedOffer
 134         } else {
 135           handleIceRequest(msg)
 136         }
 137       }
 138       else {
 139         if (msg.ice) {
 140           console.log('Host: Client that doesnt exist is sending ice submissions')
 141         } else if (msg.sdp) {
 142           handleNewClientConnection(msg)
 143         } else {
 144           console.log('Host: Client that doesnt exist is sending ice requests')
 145         }
 146       }
 147     }
 148   })
 149 }
 150 else {
 151   document.addEventListener('DOMContentLoaded', () => {
 152     document.body.innerHTML = 'Websockets not supported in your browser'
 153   })
 154 }