[$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} = 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 (once normalised).
-  // https://bugs.chromium.org/p/chromium/issues/detail?id=805649

[kzar, 2018/01/26 18:12:37]

This bug is also potentially relevant for our ext/background.js code, I'm going
to look into that next week.

-  if (details.type == "xmlhttprequest" &&
-      (details.tabId > -1 || details.initiator &&
-       details.url != new URL(details.initiator).toString()))
+  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);
+
+  let cspMatch = defaultMatcher.matchesAny(urlString, typeMap.CSP, hostname,
+                                           thirdParty, null, false);
+  if (cspMatch)
   {
-    return;
-  }
+    let page = new ext.Page({id: details.tabId, url: details.url});
+    let frame = ext.getFrame(details.tabId, details.frameId);
 
-  // To avoid an extra matchesAny for the common case let's assume no
-  // $genericblock filters apply when searching for a matching $csp filter,
-  // we double check later when necessary.
-  let specificOnly = false;
+    if (checkWhitelisted(page, frame))
+      return;
 
-  let url = new URL(details.url);
-  let hostname = getDecodedHostname(url);
-  let cspMatch = defaultMatcher.matchesAny(
-    details.url,
-    RegExpFilter.typeMap.CSP,
-    hostname, false, null, specificOnly
-  );
+    // 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)
+    {
+      cspMatch = defaultMatcher.matchesAny(urlString, typeMap.CSP, hostname,
+                                           thirdParty, null, specificOnly);
+      if (!cspMatch)
+        return;
+    }
 
-  if (cspMatch instanceof BlockingFilter)
-  {
-    if (details.tabId > -1)
-    {
-      let page = new ext.Page({id: details.tabId, url: details.url});
-      let frame = ext.getFrame(details.tabId, details.frameId);
+    devtools.logRequest(page, urlString, "CSP", hostname, thirdParty, null,
+                        specificOnly, cspMatch);
+    FilterNotifier.emit("filter.hitCount", cspMatch, 0, 0, page);
 
-      if (checkWhitelisted(page, frame, RegExpFilter.typeMap.DOCUMENT |
-                                          RegExpFilter.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,
-                                        RegExpFilter.typeMap.GENERICBLOCK);
-      if (specificOnly)
-      {
-        cspMatch = defaultMatcher.matchesAny(
-          details.url,
-          RegExpFilter.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 (defaultMatcher.whitelist.matchesAny(stringifyURL(url),
-                                                 RegExpFilter.typeMap.DOCUMENT |
-                                                   RegExpFilter.typeMap.CSP,
-                                                 hostname))
-    {
+    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"]);