[$csp4 adblockpluschrome] Issue 5241 - Add support for Content Security Policy filters

lib/csp.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 "use strict";
 
 const {defaultMatcher} = require("matcher");
-const {BlockingFilter,
-       RegExpFilter,
-       WhitelistFilter} = require("filterClasses");
-const {getDecodedHostname, stringifyURL} = require("url");
+const {RegExpFilter, WhitelistFilter} = require("filterClasses");
+const {extractHostFromFrame, getDecodedHostname,
+       isThirdParty, stringifyURL} = require("url");
 const {checkWhitelisted} = require("whitelisting");
 const {FilterNotifier} = require("filterNotifier");
 const devtools = require("devtools");
 
 const {typeMap} = RegExpFilter;
 
 browser.webRequest.onHeadersReceived.addListener(details =>
 {
-  // Chrome seems to sometimes give the response type of "xmlhttprequest"
-  // instead of "main_frame", but when it does the tabId is always -1 and
-  // the URL matches the initiator's URL[1].
-  // Chrome also seems to not normalise the initiator URL[2].
-  // [1] - https://bugs.chromium.org/p/chromium/issues/detail?id=805649
-  // [2] - https://bugs.chromium.org/p/chromium/issues/detail?id=821042
-  if (details.type == "xmlhttprequest" &&
-      (details.tabId > -1 || details.initiator &&
-       details.url != new URL(details.initiator).toString()))
-  {
-    return;
-  }
+  let url = new URL(details.url);
+  let urlString = stringifyURL(url);
+  let parentFrame = ext.getFrame(details.tabId, details.parentFrameId);
+  let hostname = extractHostFromFrame(parentFrame) || getDecodedHostname(url);
+  let thirdParty = isThirdParty(url, hostname);
 
-  // To avoid an extra matchesAny for the common case let's assume no
-  // $genericblock filters apply when searching for a matching $csp filter,
-  // we can double check later if necessary.
-  let specificOnly = false;
-
-  let url = new URL(details.url);
-  let hostname = getDecodedHostname(url);
-  let cspMatch = defaultMatcher.matchesAny(details.url, typeMap.CSP, hostname,
-                                           false, null, specificOnly);
-  let page = null;
-
+  let cspMatch = defaultMatcher.matchesAny(urlString, typeMap.CSP, hostname,
+                                           thirdParty, null, false);
   if (cspMatch)
   {
-    if (details.tabId > -1)
+    let page = new ext.Page({id: details.tabId, url: details.url});
+    let frame = ext.getFrame(details.tabId, details.frameId);
+
+    if (checkWhitelisted(page, frame))
+      return;
+
+    // To avoid an extra matchesAny for the common case we assumed no
+    // $genericblock filters applied when searching for a matching $csp filter.
+    // We must now pay the price by first checking for a $genericblock filter
+    // and if necessary that our $csp filter is specific.
+    let specificOnly = !!checkWhitelisted(page, frame, typeMap.GENERICBLOCK);
+    if (specificOnly)
     {
-      page = new ext.Page({id: details.tabId, url: details.url});
-
-      if (cspMatch instanceof WhitelistFilter)
-      {
-        if (devtools)
-        {
-          devtools.logWhitelistedDocument(page, details.url, typeMap.CSP,
-                                          hostname, cspMatch);
-        }
+      cspMatch = defaultMatcher.matchesAny(urlString, typeMap.CSP, hostname,
+                                           thirdParty, null, specificOnly);
+      if (!cspMatch)
         return;
-      }
-
-      let frame = ext.getFrame(details.tabId, details.frameId);
-
-      if (checkWhitelisted(page, frame, typeMap.DOCUMENT | typeMap.CSP))
-        return;
-
-      // We pay the price now for skipping the specificOnly check earlier, we
-      // must check again for a CSP filter, this time making sure it's specific.
-      specificOnly = !!checkWhitelisted(page, frame, typeMap.GENERICBLOCK);
-      if (specificOnly)
-      {
-        cspMatch = defaultMatcher.matchesAny(details.url, typeMap.CSP, hostname,
-                                             false, null, specificOnly);
-        if (!(cspMatch instanceof BlockingFilter))
-          return;
-      }
-
-      FilterNotifier.emit("filter.hitCount", cspMatch, 0, 0, page);
-    }
-    // If we don't know the associated tab we'll have to check that if the URL
-    // is whitelisted manually. Things like $sitekey whitelisting and filter hit
-    // logging won't work, but it's the best we can do.
-    else if (cspMatch instanceof WhitelistFilter ||
-             defaultMatcher.whitelist.matchesAny(stringifyURL(url),
-                                                 typeMap.DOCUMENT | typeMap.CSP,
-                                                 hostname))
-    {
-      return;
     }
 
-    if (devtools)
-    {
-      devtools.logRequest(page, details.url, "CSP", hostname,
-                          false, null, specificOnly, cspMatch);
-    }
+    devtools.logRequest(page, urlString, "CSP", hostname, thirdParty, null,
+                        specificOnly, cspMatch);
+    FilterNotifier.emit("filter.hitCount", cspMatch, 0, 0, page);
+
+    if (cspMatch instanceof WhitelistFilter)
+      return;
 
     details.responseHeaders.push({
       name: "Content-Security-Policy",
       value: cspMatch.csp
     });
 
     return {responseHeaders: details.responseHeaders};
   }
 }, {
   urls: ["http://*/*", "https://*/*"],
-  types: ["main_frame", "sub_frame", "xmlhttprequest"]
+  types: ["main_frame", "sub_frame"]
 }, ["blocking", "responseHeaders"]);