Added handling of $sitekey exceptions

webrequest.js

Index: webrequest.js
===================================================================
--- a/webrequest.js
+++ b/webrequest.js
@@ -1,16 +1,16 @@
 /*
  * This Source Code is subject to the terms of the Mozilla Public License
  * version 2.0 (the "License"). You can obtain a copy of the License at
  * http://mozilla.org/MPL/2.0/.
  */
 
 chrome.webRequest.onBeforeRequest.addListener(onBeforeRequest, {urls: ["http://*/*", "https://*/*"]}, ["blocking"]);
-chrome.webRequest.onBeforeSendHeaders.addListener(onBeforeSendHeaders, {urls: ["http://*/*", "https://*/*"]}, ["requestHeaders", "blocking"]);
+chrome.webRequest.onHeadersReceived.addListener(onHeadersReceived, {urls: ["http://*/*", "https://*/*"]}, ["responseHeaders"]);
 chrome.tabs.onRemoved.addListener(forgetTab);
 
 var frames = {};
 
 function onBeforeRequest(details)
 {
   if (details.tabId == -1)
     return {};
@@ -41,29 +41,71 @@ function onBeforeRequest(details)
       return {redirectUrl: "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAACklEQVR4nGMAAQAABQABDQottAAAAABJRU5ErkJggg=="};
     else
       return {cancel: true};
   }
   else
     return {};
 }
 
-function onBeforeSendHeaders(details)
+function onHeadersReceived(details)
 {
-  var match = defaultMatcher.matchesAny(details.url, "DONOTTRACK", null, false);
-  if (match && match instanceof BlockingFilter)
+  if (details.tabId == -1)
+    return;
+
+  var type = details.type;
+  if (type != "main_frame" && type != "sub_frame")
+    return;
+
+  var url = getFrameUrl(details.tabId, details.frameId);
+  if (url != details.url)
+    return;
+
+  var key = null;
+  var signature = null;
+  for (var i = 0; i < details.responseHeaders.length; i++)
   {
-    var headers = details.requestHeaders || [];
-    if (!headers.some(function(header) { header.name == "DNT";}))
+    var header = details.responseHeaders[i];
+    if (header.name.toLowerCase() == "x-adblock-key" && header.value)
     {
-      headers.push({name: "DNT", value: "1"});
-      return {requestHeaders: headers};
+      var index = header.value.indexOf("_");
+      if (index >= 0)
+      {
+        var key = header.value.substr(0, index);
+        var signature = header.value.substr(index + 1);
+        break;
+      }
     }
   }
-  return null;
+  if (!key)
+    return;
+
+  var parentUrl = null;
+  if (type == "sub_frame")
+    parentUrl = getFrameUrl(details.tabId, details.parentFrameId);
+  if (!parentUrl)
+    parentUrl = url;
+  var docDomain = extractHostFromURL(parentUrl);
+  var keyMatch = defaultMatcher.matchesByKey(url, key.replace(/=/g, ""), docDomain);
+  if (keyMatch)
+  {
+    // Website specifies a key that we know but is the signature valid?
+    var uri = new URI(url);
+    var host = uri.asciiHost;
+    if (uri.port > 0)
+      host += ":" + uri.port;
+
+    var params = [
+      uri.path.replace(/#.*/, ""),  // REQUEST_URI
+      host,                         // HTTP_HOST
+      window.navigator.userAgent    // HTTP_USER_AGENT
+    ];
+    if (verifySignature(key, signature, params.join("\0")))
+      frames[details.tabId][details.frameId].keyException = true;
+  }
 }
 
 function recordFrame(tabId, frameId, parentFrameId, frameUrl)
 {
   if (!(tabId in frames))
     frames[tabId] = {};
   frames[tabId][frameId] = {url: frameUrl, parent: parentFrameId};
 }
@@ -105,12 +147,14 @@ function checkRequest(type, tabId, url, 
 function isFrameWhitelisted(tabId, frameId, type)
 {
   var parent = frameId;
   while (parent != -1)
   {
     var parentUrl = getFrameUrl(tabId, parent);
     if (parentUrl && isWhitelisted(parentUrl, type))
       return true;
+    if (parentUrl && "keyException" in frames[tabId][frameId])
+      return true;
     parent = getFrameParent(tabId, parent);
   }
   return false;
 }