[$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
@@ skipping 13 matching lines @@
 const {checkWhitelisted} = require("whitelisting");
 const {FilterNotifier} = require("filterNotifier");
 const devtools = require("devtools");
 
 const {typeMap} = RegExpFilter;
 
 browser.webRequest.onHeadersReceived.addListener(details =>
 {
   let url = new URL(details.url);
   let urlString = stringifyURL(url);
-  let parentFrame = details.parentFrameId != -1 &&

[Sebastian Noack, 2018/03/19 22:25:12]

Nit: ext.getFrame(details.tabId, -1) just returns undefined, rendering this
check redundant.

[kzar, 2018/03/20 09:02:31]

Done.

-                      ext.getFrame(details.tabId, details.parentFrameId);
+  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)
   {
     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);

[Sebastian Noack, 2018/03/19 22:25:12]

checkWhitelisted() returns a filter object (or null).
Both, in lib/requestBlocker.js and lib/popupBlocker.js,
we turn it into a boolean (using !!), before passing the value to matchesAny().

[kzar, 2018/03/20 09:02:31]

Done.

+    let specificOnly = !!checkWhitelisted(page, frame, typeMap.GENERICBLOCK);
     if (specificOnly)
     {
       cspMatch = defaultMatcher.matchesAny(urlString, typeMap.CSP, hostname,
                                            thirdParty, null, specificOnly);
       if (!cspMatch)
         return;
     }
 
     devtools.logRequest(page, urlString, "CSP", hostname, thirdParty, null,
                         specificOnly, cspMatch);
+    FilterNotifier.emit("filter.hitCount", cspMatch, 0, 0, page);
 
     if (cspMatch instanceof WhitelistFilter)
       return;
 
-    FilterNotifier.emit("filter.hitCount", cspMatch, 0, 0, page);

[Sebastian Noack, 2018/03/19 22:25:12]

This seems inconsistent. For requests, we emit filter.hitCount also if a
whitelisting filter matched. For reference, it seems that for popups we don't
emit filter.hitCount at all, but IMO this is a bug.

[kzar, 2018/03/20 09:02:31]

Done.

     details.responseHeaders.push({
       name: "Content-Security-Policy",
       value: cspMatch.csp
     });
 
     return {responseHeaders: details.responseHeaders};
   }
 }, {
   urls: ["http://*/*", "https://*/*"],
   types: ["main_frame", "sub_frame"]
 }, ["blocking", "responseHeaders"]);