Cefsharp 禁用WebRTC的办法

网上没什么方案，最靠谱的方案是使用插件，调用

chrome.privacy.network.webRTCIPHandlingPolicy.set({
            value: 'default_public_interface_only'
          });

改变WebRTC策略。

一般通过WebRTC获取IP的代码如下：

function get_webrtc() {
	//get the IP addresses associated with an account
	function getIPs(callback){
		var ip_dups = {};

		//compatibility for firefox and chrome
		var RTCPeerConnection = window.RTCPeerConnection
			|| window.mozRTCPeerConnection
			|| window.webkitRTCPeerConnection
			|| window.msRTCPeerConnection;


		//bypass naive webrtc blocking using an iframe
		if(!RTCPeerConnection){
			
			// SINGLE IFRAME
			$('body').append('');
			var win = document.getElementById('iframe').contentWindow;
			RTCPeerConnection = win.RTCPeerConnection
				|| win.mozRTCPeerConnection
				|| win.webkitRTCPeerConnection
				|| win.msRTCPeerConnection;

		}

		//minimal requirements for data connection
		var mediaConstraints = {
			optional: [{RtpDataChannels: true}]
		};

		var servers = {iceServers: [{urls: "stun:stun.l.google.com:19302?transport=udp"}]};

		//construct a new RTCPeerConnection
		//var pc = new RTCPeerConnection(servers, mediaConstraints);
		try {
			var pc = new RTCPeerConnection(servers, mediaConstraints);
		} catch (e) {
			return;
		}

		function handleCandidate(candidate){
			//match just the IP address
			var ip_regex = /([0-9]{1,3}(\.[0-9]{1,3}){3})/;
				if(ip_regex.exec(candidate) && ip_regex.exec(candidate).length > 1) {
				var ip_addr = ip_regex.exec(candidate)[1];

				//remove duplicates
				if(ip_dups[ip_addr] === undefined)
					callback(ip_addr);

				ip_dups[ip_addr] = true;
			}
		}

		//listen for candidate events
		//pc.onicecandidate = function(ice){
		
			//console.log('ice.candidate.candidate='+ice.candidate.candidate);

			//skip non-candidate events
			//ice.candidate && handleCandidate(ice.candidate.candidate);
		//};

		//create a bogus data channel
		//pc.createDataChannel("");
		try {
			pc.createDataChannel("bl");
		} catch (k) {}

		try {
			pc.createOffer().then(function(result) {
				pc.setLocalDescription(result);
			});
		}
		catch(e) {
			//create an offer sdp
			pc.createOffer(function(result){
				//trigger the stun server request
				pc.setLocalDescription(result, function(){}, function(){});
			}, function(){});
		}

		//wait for a while to let everything done
		setTimeout(function(){
			//read candidate info from local description
			pc.localDescription.sdp.split('\n').forEach(function(line){
				if(line.indexOf('a=candidate:') === 0) {
					//console.log('line='+line);
					handleCandidate(line);
				}
			});
		}, 1000);
	}


	//insert IP addresses into the page
	getIPs(function(ip){
		//console.log(ip);
		if(!$('#webrtc_loc').length) {
			$('#webrtc').removeClass('disabled').html(
				'
'+dic['loc_ip']+':
' +
				'
'+dic['pub_ip']+':
' +
				'
'
			);
		}
		//local IPs
		if (ip.match(/^(192\.168\.|169\.254\.|10\.|127\.|172\.(1[6-9]|2\d|3[01])\.)/)) {
			$('#webrtc_loc').append('
'+ip+'');
		}
		//assume the rest are public IPs
		else {
			$.getJSON("/ip2loc/?i="+ip, function(data) {
				//console.log(data);
				$('#webrtc_pub').append('
 '+data.ip+' 
 '+data.cn+(data.ci!=null?', '+data.ci:'')+'');
			});
		}
	});
}

由于Cefsharp 添加浏览器插件 挺麻烦，最后想到一招。注入js，修改掉 

var RTCPeerConnection = window.RTCPeerConnection
            || window.mozRTCPeerConnection
            || window.webkitRTCPeerConnection
            || window.msRTCPeerConnection;

这个对象。

即注入脚本，重定义RTCPeerConnection这个对象，让获取ip的代码不能正常运行。

console.log("Disable WebRTC Begin......");
window.RTCPeerConnection = {};
window.webkitRTCPeerConnection = {};
window.msRTCPeerConnection = {};
window.mozRTCPeerConnection = {};
console.log("Disable WebRTC End......");

// 实现ChromiumWebBrowser的FrameLoadStart事件
public event EventHandler FrameLoadStart;

// 实现代码为
void wb_FrameLoadStart(object sender, CefSharp.FrameLoadStartEventArgs e)
        {
            if (AppSetting.FrameLoadStartScript != null && AppSetting.FrameLoadStartScript.Length > 0)
            {
                e.Frame.ExecuteJavaScriptAsync(AppSetting.FrameLoadStartScript);
            }
        }