host.js

   1 document.title = "Strapp.io Host"
   2
   3
   4 const conf = {"iceServers": [{ "urls": "stun:stun.1.google.com:19302" }] }
   5 const clients = new Map([])
   6 const iceCandidates = []
   7 let dataChannel
   8 let screenStream /* TODO: Remove if can access localStreams */
   9 let tracks = []
  10
  11
  12 /* TODO: duplicate in both client.js and host.jhs */
  13 function getPublicKey() {
  14   return new Promise( (resolve, reject) => {
  15     /* Check local storage for public key */
  16     if (!window.localStorage.getItem('public-key')) {
  17       console.log('public key is undefined')
  18       /* If doesn't exist, generate public and private key pair, store in
  19       local storage */
  20       crypto.subtle.generateKey(
  21         { name:'RSA-OAEP',
  22         modulusLength: 2048,
  23         publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
  24         hash: {name: "SHA-256"}
  25       },
  26       true,
  27       ['encrypt', 'decrypt']
  28     ).then((keyPair) => {
  29       /* TODO: Do we need to store the private key as well? */
  30       crypto.subtle.exportKey('jwk', keyPair.publicKey)
  31       .then((exportedKey) => {
  32         window.localStorage.setItem('publicKey', exportedKey)
  33         console.log('public key is' + window.localStorage.getItem('publicKey'))
  34         resolve(exportedKey)
  35       })
  36
  37     })
  38   }
  39   else {
  40     resolve(window.localStorage.getItem('publicKey'))
  41     }
  42   })
  43 }
  44
  45 function handleNewClientConnection(offer) {
  46   /* New Client Connection*/
  47   hpc = new RTCPeerConnection(conf)
  48   //console.log(offer)
  49   clients.set(offer.pubKey, hpc)
  50   hpc.setRemoteDescription(offer.sdp)
  51   .then(() => {
  52     hpc.createAnswer().then((answer) => {
  53       return hpc.setLocalDescription(answer)
  54     })
  55     .then(() => {
  56       getPublicKey().then((hpk) => {
  57         hpc['hpk'] = hpk
  58         hpc.onicecandidate = (event) => {
  59           if (event.candidate) {
  60             console.log('Host: Allocating ice candidate for client')
  61             iceCandidates.push(JSON.stringify({
  62               cmd: "< ice pubKey",
  63               ice: event.candidate,
  64               hostPubKey: hpk.n, /* TODO: do we need to send this? */
  65               clientPubKey: offer.pubKey,
  66               iceState: "a"
  67             }))
  68           }
  69           else {
  70             console.log('Host: Finished sending ICE candidates')
  71           }
  72         }
  73         console.log('Host: Sending answer to Client ')
  74         wsock.send(JSON.stringify({
  75           cmd: '< sdp pubKey',
  76           sdp: hpc.localDescription,
  77           hostPubKey: hpk.n,
  78           clientPubKey: offer.pubKey
  79         }))
  80
  81
  82       })
  83     }).catch((err) => {
  84       console.log(`error in host answer ${err}`)
  85     })
  86   })
  87   hpc.oniceconnectionstatechange = () => {
  88     console.log('iceConnectionState = ' + hpc.iceConnectionState)
  89   }
  90   hpc.ondatachannel = (evt) => {
  91     dataChannel = evt.channel
  92     dataChannel.onmessage = (msg) => {
  93       let clientMessage = JSON.parse(msg.data)
  94       console.log(clientMessage)
  95       hpc.setRemoteDescription(clientMessage.sdp).then(() => {
  96         console.log('should be streaming now')
  97       })
  98     }
  99     dataChannel.onopen = () => {
 100       screenStream.getTracks().forEach( (track) => {
 101         hpc.addTrack(track, screenStream)
 102       })
 103       console.log(hpc.getSenders())
 104       /* Create offer */
 105       hpc.createOffer().then((offer) => {
 106         return hpc.setLocalDescription(offer)
 107       }).then( () => {
 108         dataChannel.send(JSON.stringify({
 109           "cmd": "< screen dataChannel",
 110           "sdp": hpc.localDescription,
 111           "pubKey": hpc['hpk'].n
 112         }))
 113       })
 114     }
 115   }
 116   hpc.onnegotiationneeded = () => {
 117     console.log('negotiation needed')
 118   }
 119
 120 }
 121
 122 function handleNewIceSubmission(msg) {
 123   console.log('Host: Adding new ice candidate')
 124   const hpc = clients.get(msg.pubKey)
 125   let candidate = new RTCIceCandidate(msg.ice)
 126   hpc.addIceCandidate(candidate)
 127 }
 128
 129 function handleIceRequest(msg) {
 130   console.log('Host: Handling ice candidate request')
 131   console.log(iceCandidates)
 132   const hpc = clients.get(msg.pubKey)
 133   const iceCandidate = iceCandidates.pop()
 134   if (iceCandidate !== undefined) {
 135     wsock.send(iceCandidate)
 136   } else {
 137     if (hpc.iceGatheringState.localeCompare('gathering') === 0) {
 138       wsock.send(`{"cmd" : "< ice pubKey", "clientPubKey":"${msg.pubKey}", "iceState": "g"}`)
 139     }
 140     else if (hpc.iceGatheringState.localeCompare('complete') === 0) {
 141       wsock.send(`{"cmd" : "< ice pubKey", "clientPubKey":"${msg.pubKey}", "iceState": "c"}`)
 142     }
 143
 144   }
 145
 146 }
 147 if ("WebSocket" in window) {
 148   document.addEventListener('DOMContentLoaded', (event) => {
 149     document.body.innerHTML = '<div>Choose options for client</div> <video autoplay></video>'
 150     navigator.mediaDevices.getUserMedia({
 151         video : { mediaSource: "screen",
 152         width: {max: '1920'},
 153         height: {max: '1080'},
 154         frameRate: {max: '10'}} })
 155     .then(function(mediaStream) {
 156       let video = document.querySelector('video')
 157       screenStream = mediaStream
 158       console.log(mediaStream)
 159       video.srcObject = mediaStream
 160       console.log('Grabbed media')
 161       video.onloadedmetadata = function(e) {
 162         console.log(e)
 163         video.play()
 164       }
 165     })
 166     .catch(function(err) {
 167       document.body.innerHTML = 'Help me help you. Reload the page and allow screen sharing!'
 168       console.log(err);
 169     }); // always check for errors at the end.
 170
 171     wsock = new WebSocket(`${_strapp_protocol}://${window.location.hostname}:${_strapp_port}`)
 172     wsock.onopen = () => {
 173       console.log(`Strapped to ${_strapp_protocol}://${window.location.hostname}:${_strapp_port}`)
 174     }
 175
 176     wsock.onmessage = (serverMsg) => {
 177       /* msg is either offer or ice candidate or ice candidate request*/
 178
 179       /* What if data null? */
 180       let msg = JSON.parse(serverMsg.data)
 181
 182       const clientID = msg.pubKey
 183
 184       /* TODO: redo this trash */
 185       if (clients.has(clientID)) {
 186         if (msg.ice) {
 187           handleNewIceSubmission(msg)
 188         } else if (msg.sdp) {
 189           //handleRepeatedOffer
 190         } else {
 191           handleIceRequest(msg)
 192         }
 193       }
 194       else {
 195         if (msg.ice) {
 196           console.log('Host: Client that doesnt exist is sending ice submissions')
 197         } else if (msg.sdp) {
 198           handleNewClientConnection(msg)
 199         } else {
 200           console.log('Host: Client that doesnt exist is sending ice requests')
 201         }
 202       }
 203     }
 204
 205
 206
 207   })
 208 }
 209 else {
 210   document.addEventListener('DOMContentLoaded', () => {
 211     document.body.innerHTML = 'Websockets not supported in your browser'
 212   })
 213 }