[$csp2 adblockpluscore] Issue 6329 - Add the CSP filter type

lib/filterClasses.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 685 matching lines @@
 });
 
 /**
  * Creates a RegExp filter from its text representation
  * @param {string} text   same as in Filter()
  * @return {Filter}
  */
 RegExpFilter.fromText = function(text)
 {
   let contentType = null;
+  let csp = null;
   let matchCase = null;
   let domains = null;
   let sitekeys = null;
   let thirdParty = null;
   let collapse = null;
   let origText;
 
   let match = (text.indexOf("$") >= 0 ? Filter.optionsRegExp.exec(text) : null);
   if (!match)
   {
     origText = text = text.replace(/\s/g, "");
   }
   else
   {
     text = match.input.substring(0, match.index).replace(/\s/g, "");
-    let options = match[1].replace(/\s/g, "");
+
+    // Strip all whitespace from the options string, except for CSP values which
+    // we only trim.
+    let rawOptions = match[1];
+    let options = "";
+    let offset = 0;
+    let cspMatch;
+    let cspRegexp = /((?:^|,)csp=)([^,]+)/gi;
+    while ((cspMatch = cspRegexp.exec(rawOptions)))
+    {
+      options += rawOptions.substring(offset, cspMatch.index).replace(/\s/g, "");
+      options += cspMatch[1] + cspMatch[2].trim();
+      offset = cspRegexp.lastIndex;
+    }
+    options += rawOptions.substring(offset).replace(/\s/g, "");
+
     origText = text + "$" + options;
 
     for (let option of options.toUpperCase().split(","))
     {
       let value = null;
       let separatorIndex = option.indexOf("=");
       if (separatorIndex >= 0)
       {
         value = option.substr(separatorIndex + 1);
         option = option.substring(0, separatorIndex);
       }
       option = option.replace(/-/, "_");
       if (option in RegExpFilter.typeMap)
       {
         if (contentType == null)
           contentType = 0;
         contentType |= RegExpFilter.typeMap[option];
+
+        if (option == "CSP" && typeof value == "string")
+        {
+          csp = value.toLowerCase();

[Manish Jethani, 2018/02/06 05:54:20]

We could avoid uppercasing and then lowercasing the value here by first only
uppercasing the name part of the option and here deciding if the value should be
uppercase or lowercase.

[kzar, 2018/03/06 15:37:53]

Done.

+          // Quick check to prevent report-uri and report-to directives
+          if (csp.includes("report-"))

[Manish Jethani, 2018/02/06 05:54:20]

Couldn't the value contain "report-" in a different place than the directive
name? e.g. "default-src https://report-generator.example.com". I think this
check should be more specific.

[kzar, 2018/03/06 15:37:53]

Done.

+            return new InvalidFilter(origText, "filter_invalid_csp");
+        }
       }
       else if (option[0] == "~" && option.substr(1) in RegExpFilter.typeMap)
       {
         if (contentType == null)
           ({contentType} = RegExpFilter.prototype);
         contentType &= ~RegExpFilter.typeMap[option.substr(1)];
       }
       else if (option == "MATCH_CASE")
         matchCase = true;
       else if (option == "~MATCH_CASE")
@@ skipping 16 matching lines @@
   }
 
   try
   {
     if (text.indexOf("@@") == 0)
     {
       return new WhitelistFilter(origText, text.substr(2), contentType,
                                  matchCase, domains, thirdParty, sitekeys);
     }
     return new BlockingFilter(origText, text, contentType, matchCase, domains,
-                              thirdParty, sitekeys, collapse);
+                              thirdParty, sitekeys, collapse, csp);
   }
   catch (e)
   {
     return new InvalidFilter(origText, "filter_invalid_regexp");
   }
 };
 
 /**
  * Maps type strings like "SCRIPT" or "OBJECT" to bit masks
  */
 RegExpFilter.typeMap = {
   OTHER: 1,
   SCRIPT: 2,
   IMAGE: 4,
   STYLESHEET: 8,
   OBJECT: 16,
   SUBDOCUMENT: 32,
   DOCUMENT: 64,
   WEBSOCKET: 128,
+  CSP: 512,

[Manish Jethani, 2018/02/06 05:54:20]

Perhaps a good idea to place CSP after WEBRTC?

[kzar, 2018/03/06 15:37:53]

Done.

   WEBRTC: 256,
   XBL: 1,
   PING: 1024,
   XMLHTTPREQUEST: 2048,
   OBJECT_SUBREQUEST: 4096,
   DTD: 1,
   MEDIA: 16384,
   FONT: 32768,
 
   BACKGROUND: 4,    // Backwards compat, same as IMAGE
 
   POPUP: 0x10000000,
   GENERICBLOCK: 0x20000000,
   ELEMHIDE: 0x40000000,
   GENERICHIDE: 0x80000000
 };
 
-// DOCUMENT, ELEMHIDE, POPUP, GENERICHIDE and GENERICBLOCK options shouldn't
-// be there by default
-RegExpFilter.prototype.contentType &= ~(RegExpFilter.typeMap.DOCUMENT |
+// CSP, DOCUMENT, ELEMHIDE, POPUP, GENERICHIDE and GENERICBLOCK options
+// shouldn't be there by default
+RegExpFilter.prototype.contentType &= ~(RegExpFilter.typeMap.CSP |
+                                        RegExpFilter.typeMap.DOCUMENT |
                                         RegExpFilter.typeMap.ELEMHIDE |
                                         RegExpFilter.typeMap.POPUP |
                                         RegExpFilter.typeMap.GENERICHIDE |
                                         RegExpFilter.typeMap.GENERICBLOCK);
 
 /**
  * Class for blocking filters
  * @param {string} text see Filter()
  * @param {string} regexpSource see RegExpFilter()
  * @param {number} contentType see RegExpFilter()
  * @param {boolean} matchCase see RegExpFilter()
  * @param {string} domains see RegExpFilter()
  * @param {boolean} thirdParty see RegExpFilter()
  * @param {string} sitekeys see RegExpFilter()
  * @param {boolean} collapse
  *   defines whether the filter should collapse blocked content, can be null
+ * @param {string} [csp]
+ *   Content Security Policy to inject when the filter matches
  * @constructor
  * @augments RegExpFilter
  */
 function BlockingFilter(text, regexpSource, contentType, matchCase, domains,
-                        thirdParty, sitekeys, collapse)
+                        thirdParty, sitekeys, collapse, csp)
 {
   RegExpFilter.call(this, text, regexpSource, contentType, matchCase, domains,
                     thirdParty, sitekeys);
 
   this.collapse = collapse;
+  this.csp = csp;
 }
 exports.BlockingFilter = BlockingFilter;
 
 BlockingFilter.prototype = extend(RegExpFilter, {
   type: "blocking",
 
   /**
    * Defines whether the filter should collapse blocked content.
    * Can be null (use the global preference).
    * @type {boolean}
    */
-  collapse: null
+  collapse: null,
+
+  /**
+   * Content Security Policy to inject for matching requests.
+   * @type {string}
+   */
+  csp: null
 });
 
 /**
  * Class for whitelist filters
  * @param {string} text see Filter()
  * @param {string} regexpSource see RegExpFilter()
  * @param {number} contentType see RegExpFilter()
  * @param {boolean} matchCase see RegExpFilter()
  * @param {string} domains see RegExpFilter()
  * @param {boolean} thirdParty see RegExpFilter()
@@ skipping 144 matching lines @@
  */
 function ElemHideEmulationFilter(text, domains, selector)
 {
   ElemHideBase.call(this, text, domains, selector);
 }
 exports.ElemHideEmulationFilter = ElemHideEmulationFilter;
 
 ElemHideEmulationFilter.prototype = extend(ElemHideBase, {
   type: "elemhideemulation"
 });