Added navigator protection

lib/navigator.js

@@ -0,0 +1,116 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+(function(){
+	"use strict";
+	
+	var scope;
+	if ((typeof exports) !== "undefined"){
+		scope = exports;
+	}
+	else {
+		scope = require.register("./navigator", {});
+	}
+	
+	const settings = require("./settings");
+	const logging = require("./logging");
+	
+	scope.allProperties = [
+		"appCodeName", "appName",
+		"appVersion", "buildID", "oscpu", "platform",
+		"product",
+		"productSub", "userAgent", "vendor", "vendorSub"];
+	const original = {};
+	scope.allProperties.forEach(function(property){
+		original[property] = window.navigator[property];
+	});
+	original["real Firefox version"] = window.navigator.userAgent.replace(/^.+Firefox\//, "");
+	
+	let changedValues = {};
+	
+	settings.onloaded(function(){
+		changedValues = settings.navigatorDetails;
+	});
+	settings.on("navigatorDetails", function({newValue}){
+		changedValues = newValue;
+	});
+	
+	
+	function getValue(name, stack = []){
+		if (stack.indexOf(name) !== -1){
+			return "[ERROR: loop in property definition]";
+		}
+		stack.push(name);
+		
+		switch (name){
+			case "original value":
+				return original[stack[stack.length - 2]];
+			case "random":
+				return String.fromCharCode(Math.floor(65 + 85 * Math.random()));
+			default:
+				if (changedValues.hasOwnProperty(name)){
+					return parseString(changedValues[name], stack.slice());
+				}
+				else {
+					return original[name];
+				}
+		}
+	}
+	function parseString(string, stack){
+		return string.replace(/{([a-z[\]_. -]*)}/ig, function(m, name){
+			return getValue(name, stack.slice());
+		});
+	}
+	
+	scope.getNavigatorValue = function getNavigatorValue(name){
+		return getValue(name);
+	};
+	
+	function changeHTTPHeader(details){
+		if (
+			settings.protectNavigator &&
+			(
+				!settings.protectedAPIFeatures.hasOwnProperty("userAgent") ||
+				settings.protectedAPIFeatures.userAgent
+			)
+		){
+			for (var header of details.requestHeaders){
+				if (header.name.toLowerCase() === "user-agent"){
+					header.value = getValue("userAgent");
+				}
+			}
+		}
+		return details;
+	}
+	
+	scope.registerHeaderChange = function(){
+		logging.message("Register HTTP header modification for navigator protection.");
+		if (!browser.webRequest.onBeforeSendHeaders.hasListener(changeHTTPHeader)){
+			browser.webRequest.onBeforeSendHeaders.addListener(
+				changeHTTPHeader,
+				{
+					urls: ["<all_urls>"],
+				},
+				["blocking", "requestHeaders"]);
+		}
+	};
+	scope.unregisterHeaderChange = function(){
+		logging.message("Removing header modification for navigator protection.");
+		browser.webRequest.onBeforeSendHeaders.removeListener(changeHTTPHeader);
+	};
+	scope.init = function (){
+		settings.onloaded(function(){
+			if (!settings.protectNavigator){
+				scope.unregisterHeaderChange();
+			}
+		});
+		settings.on("protectNavigator", function({newValue}){
+			if (newValue){
+				scope.registerHeaderChange();
+			}
+			else {
+				scope.unregisterHeaderChange();
+			}
+		});
+	};
+}());