[$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 =>
 {
   let url = new URL(details.url);
   let urlString = stringifyURL(url);
-  let hostname = getDecodedHostname(url);

[Sebastian Noack, 2018/03/14 20:19:42]

This seems inconsistent with the semantics of request blocking, where the
$domain option refers to the hostname of the parent document.

[kzar, 2018/03/15 13:10:13]

Well I suppose with request blocking we are generally blocking a request,
instead of injecting something that will then block child requests (or similar).
I'm not sure what else we can do here, do you have any suggestions?

[Sebastian Noack, 2018/03/15 17:14:25]

I don't see how the difference between blocking requests vs injecting headers,
calls for an inconsistency here. FWIW $popup filters have the same semantics.

We have access to the parentFrameId, and can get the parent frame's URL, to make
the behavior consistent here. So that ||foo.com$csp=...,domain=bar.com, only
injects a CSP on foo.com if embedded in a frame on bar.com.

[kzar, 2018/03/15 18:18:44]

Done, look OK?

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