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               iceCandidateAvailable: true
  62             }))
  63           }
  64           else {
  65             console.log('Host: Finished sending ICE candidates')
  66           }
  67         }
  68         console.log('Host: Sending answer to Client')
  69         wsock.send(JSON.stringify({
  70           cmd: '< sdp pubKey',
  71           sdp: hpc.localDescription,
  72           hostPubKey: hpk.n,
  73           clientPubKey: offer.pubKey
  74         }))
  75         hpc.ondatachannel = (evt) => {
  76           dataChannel = evt.channel
  77           console.log(evt)
  78           dataChannel.onmessage = (msg) => {
  79             console.log(msg.data)
  80           }
  81           dataChannel.onopen = () => {
  82             dataChannel.send(`Hi ${offer.pubKey} -host`)
  83           }
  84         }
  85         hpc.oniceconnectionstatechange = () => {
  86           console.log('iceConnectionState = ' + hpc.iceConnectionState)
  87         }
  88       })
  89     }).catch((err) => {
  90       console.log(`error in host answer ${err}`)
  91     })
  92   })
  93
  94
  95
  96 }
  97
  98 function handleNewIceSubmission(msg) {
  99   console.log('Host: Adding new ice candidate')
 100   const hpc = clients.get(msg.pubKey)
 101   let candidate = new RTCIceCandidate(msg.ice)
 102   hpc.addIceCandidate(candidate)
 103 }
 104
 105 function handleIceRequest(msg) {
 106   console.log('Host: Handling ice candidate request')
 107   console.log(iceCandidates)
 108   const hpc = clients.get(msg)
 109   const iceCandidate = iceCandidates.pop()
 110   if (iceCandidate !== undefined) {
 111     wsock.send(iceCandidate)
 112   } else {
 113     wsock.send(`{"cmd" : "< ice pubKey", "clientPubKey":"${msg.pubKey}", "iceCandidateAvailable": false}`)
 114   }
 115
 116 }
 117 if ("WebSocket" in window) {
 118   document.addEventListener('DOMContentLoaded', (event) => {
 119     wsock = new WebSocket(`${_strapp_protocol}://${window.location.hostname}:${_strapp_port}`)
 120     wsock.onopen = () => {
 121       console.log(`Strapped to ${_strapp_protocol}://${window.location.hostname}:${_strapp_port}`)
 122     }
 123
 124     wsock.onmessage = (serverMsg) => {
 125       /* msg is either offer or ice candidate or ice candidate request*/
 126
 127       /* What if data null? */
 128       let msg = JSON.parse(serverMsg.data)
 129
 130       const clientID = msg.pubKey
 131
 132       /* TODO: redo this trash */
 133       if (clients.has(clientID)) {
 134         if (msg.ice) {
 135           handleNewIceSubmission(msg)
 136         } else if (msg.sdp) {
 137           //handleRepeatedOffer
 138         } else {
 139           handleIceRequest(msg)
 140         }
 141       }
 142       else {
 143         if (msg.ice) {
 144           console.log('Host: Client that doesnt exist is sending ice submissions')
 145         } else if (msg.sdp) {
 146           handleNewClientConnection(msg)
 147         } else {
 148           console.log('Host: Client that doesnt exist is sending ice requests')
 149         }
 150       }
 151     }
 152   })
 153 }
 154 else {
 155   document.addEventListener('DOMContentLoaded', () => {
 156     document.body.innerHTML = 'Websockets not supported in your browser'
 157   })
 158 }