RTCIceCandidate no longer returning IP

Question

Just noticed that on Chrome only, RTCIceCandidate no longer returns an IP, but rather an obfuscated address.

RTCIceCandidate 
address: "a5b3ef18-2e66-4e24-91d2-893b93bbc1c1.local"
candidate: "candidate:169888242 1 udp 2113937151 a5b3ef18-2e66-4e24-91d2-893b93bbc1c1.local 47871 typ host generation 0 ufrag 7dHv network-cost 999"
component: "rtp"
foundation: "169888242"
port: 47871
priority: 2113937151
protocol: "udp"
relatedAddress: null
relatedPort: null
sdpMLineIndex: 0
sdpMid: "0"
tcpType: ""
type: "host"
usernameFragment: "7dHv"

Notice the first property of RTCIceCanadate is "address", and "ip" is no longer part of this object.

The following code determines the local IP address of a browser. Still works on MOZ.

function discover()
{
    try{
        //Get Local IP
        window.RTCPeerConnection = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection;   //compatibility for firefox and chrome

        if (pc)
            pc.close();
        
        pc = new RTCPeerConnection({iceServers:[]});   
        pc.onicecandidate = onIceCandidate;   
        pc.createDataChannel("");   
        pc.createOffer(pc.setLocalDescription.bind(pc), noop);   
    
    } catch (e)
    { console.log(e.message);}
}

function noop()
{
}

function onIceCandidate(ice)
{   
    console.log(ice.candidate);

    if(!ice || !ice.candidate || !ice.candidate.candidate)  return;
    
    var my_ip = /([0-9]{1,3}(\.[0-9]{1,3}){3}|[a-f0-9]{1,4}(:[a-f0-9]{1,4}){7})/.exec(ice.candidate.candidate)[1];

    this.onicecandidate = noop;

    ip = my_ip.split(".")[0]+'.'+my_ip.split(".")[1]+'.'+my_ip.split(".")[2];
}

Is WebRTC officially now a fractured standard? MOZ still lists "ip" as a member of RTCIceCandidate, with no mention of the "address" member that Chrome returns.

Is there a way to de-obfusucate the mDNS address back to an ip address without forcing users to mess around with browser settings they don't understand?

Answer 1

I noticed that this was happening, only returning an mDNS address (for more information about the obfuscation, read this great article completely explaining what happened).

However, I did find a new repository that seems to "fix" this (working, but not exposing the private ip, only the public). It can be found here, and the example can be found here.

Answer 2

Chrome is not broken, the WebRTC standard is evolving to prevent sites from collecting local addresses by diverting the WebRTC API. If you used this hack to obtain local addresses, you might need to find another approach.

Here are the corresponding issues for Chromium and Firefox, and the current IETF draft for WebRTC mDNS candidates.