[$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 79 matching lines @@
 Filter.elemhideRegExp = /^([^/*|@"!]*?)#([@?])?#(.+)$/;
 /**
  * Regular expression that RegExp filters specified as RegExps should match
  * @type {RegExp}
  */
 Filter.regexpRegExp = /^(@@)?\/.*\/(?:\$~?[\w-]+(?:=[^,\s]+)?(?:,~?[\w-]+(?:=[^,\s]+)?)*)?$/;
 /**
  * Regular expression that options on a RegExp filter should match
  * @type {RegExp}
  */
-Filter.optionsRegExp = /\$(~?[\w-]+(?:=[^,\s]+)?(?:,~?[\w-]+(?:=[^,\s]+)?)*)$/;
+Filter.optionsRegExp = /\$(~?[\w-]+(?:=[^,]+)?(?:,~?[\w-]+(?:=[^,]+)?)*)$/;
+
+/**
+ * Forbidden Content Security Policy directives
+ * @type {Set<string>}
+ */
+Filter.cspDirectiveBlacklist = new Set([
+  "base-uri", "referrer", "report-to", "report-uri", "base-uri",
+  "upgrade-insecure-requests"
+]);
+/**
+ * Regular expression that matches an invalid Content Security Policy
+ * @type {RegExp}
+ */
+Filter.invalidCSPRegExp = new RegExp(
+  "(;|^) ?(" + Array.from(Filter.cspDirectiveBlacklist).join("|") + ")\\b"
+);
 
 /**
  * Creates a filter of correct type from its text representation - does the
  * basic parsing and calls the right constructor then.
  *
  * @param {string} text   as in Filter()
  * @return {Filter}
  */
 Filter.fromText = function(text)
 {
@@ skipping 54 matching lines @@
  * Removes unnecessary whitespaces from filter text, will only return null if
  * the input parameter is null.
  * @param {string} text
  * @return {string}
  */
 Filter.normalize = function(text)
 {
   if (!text)
     return text;
 
-  // Remove line breaks and such
-  text = text.replace(/[^\S ]/g, "");
+  // Remove line breaks, tabs etc
+  text = text.replace(/[^\S ]+/g, "");
 
-  if (/^\s*!/.test(text))
+  // Don't remove spaces inside comments
+  if (/^ *!/.test(text))
+    return text.trim();
+
+  // Special treatment for element hiding filters, right side is allowed to
+  // contain spaces
+  if (Filter.elemhideRegExp.test(text))
   {
-    // Don't remove spaces inside comments
-    return text.trim();
+    let [, domain, separator, selector] = /^(.*?)(#@?#?)(.*)$/.exec(text);
+    return domain.replace(/ +/g, "") + separator + selector.trim();
   }
-  else if (Filter.elemhideRegExp.test(text))
+
+  // For most regexp filters we strip all spaces, but $csp filter options
+  // are allowed to contain single (non trailing) spaces.
+  let strippedText = text.replace(/ +/g, "");
+  if (!strippedText.includes("$") || !/\bcsp=/i.test(strippedText))
+    return strippedText;
+
+  let optionsMatch = Filter.optionsRegExp.exec(strippedText);
+  if (!optionsMatch)
+    return strippedText;
+
+  // For $csp filters we must first separate out the options part of the
+  // text, being careful to preserve its spaces.
+  let beforeOptions = strippedText.substring(0, optionsMatch.index);
+  let optionsText = text;
+  for (let i = -2; i != -1; i = beforeOptions.indexOf("$", i + 1))

[kzar, 2018/03/17 14:35:08]

Here you go Manish, I still don't see the point personally.

(There's another possible optimisation, the first optionsText.indexOf("$") could
start at beforeOptions.indexOf("$") or beforeOptions.length if that's -1. I
couldn't see a way to do that in practice that sped things up much however and
it hurt readability further.)

[Manish Jethani, 2018/03/19 18:03:38]

Acknowledged.

+    optionsText = optionsText.substr(optionsText.indexOf("$") + 1);
+
+  // Then we can normalize spaces in the options part safely
+  let options = optionsText.split(",");
+  for (let i = 0; i < options.length; i++)
   {
-    // Special treatment for element hiding filters, right side is allowed to
-    // contain spaces
-    let [, domain, separator, selector] = /^(.*?)(#@?#?)(.*)$/.exec(text);
-    return domain.replace(/\s/g, "") + separator + selector.trim();
+    let option = options[i];
+    let cspMatch = /^ *c *s *p *=/i.exec(option);
+    if (cspMatch)
+    {
+      options[i] = cspMatch[0].replace(/ +/g, "") +
+                   option.substr(cspMatch[0].length).trim().replace(/ +/g, " ");
+    }
+    else
+      options[i] = option.replace(/ +/g, "");
   }
-  return text.replace(/\s/g, "");
+
+  return beforeOptions + "$" + options.join();
 };
 
 /**
  * @see filterToRegExp
  */
 Filter.toRegExp = filterToRegExp;
 
 /**
  * Class for invalid filters
  * @param {string} text see Filter()
@@ skipping 519 matching lines @@
     blocking = false;
     text = text.substr(2);
   }
 
   let contentType = null;
   let matchCase = null;
   let domains = null;
   let sitekeys = null;
   let thirdParty = null;
   let collapse = null;
+  let csp = null;
   let options;
   let match = (text.indexOf("$") >= 0 ? Filter.optionsRegExp.exec(text) : null);
   if (match)
   {
-    options = match[1].toUpperCase().split(",");
+    options = match[1].split(",");
     text = match.input.substr(0, match.index);
     for (let option of options)
     {
       let value = null;
       let separatorIndex = option.indexOf("=");
       if (separatorIndex >= 0)
       {
         value = option.substr(separatorIndex + 1);
         option = option.substr(0, separatorIndex);
       }
-      option = option.replace(/-/, "_");
+      option = option.replace(/-/, "_").toUpperCase();
       if (option in RegExpFilter.typeMap)
       {
         if (contentType == null)
           contentType = 0;
         contentType |= RegExpFilter.typeMap[option];
+
+        if (option == "CSP" && typeof value != "undefined")
+        {
+          if (csp)
+            csp.push(value);
+          else
+            csp = [value];
+        }
       }
       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")
         matchCase = false;
       else if (option == "DOMAIN" && typeof value != "undefined")
-        domains = value;
+        domains = value.toUpperCase();
       else if (option == "THIRD_PARTY")
         thirdParty = true;
       else if (option == "~THIRD_PARTY")
         thirdParty = false;
       else if (option == "COLLAPSE")
         collapse = true;
       else if (option == "~COLLAPSE")
         collapse = false;
       else if (option == "SITEKEY" && typeof value != "undefined")
-        sitekeys = value;
+        sitekeys = value.toUpperCase();
       else
         return new InvalidFilter(origText, "filter_unknown_option");
     }
   }
 
   try
   {
     if (blocking)
     {
+      if (csp)
+      {
+        csp = csp.join("; ").toLowerCase();
+
+        if (Filter.invalidCSPRegExp.test(csp))
+          return new InvalidFilter(origText, "filter_invalid_csp");
+      }
+
       return new BlockingFilter(origText, text, contentType, matchCase, domains,
-                                thirdParty, sitekeys, collapse);
+                                thirdParty, sitekeys, collapse, csp);
     }
     return new WhitelistFilter(origText, text, contentType, matchCase, domains,
                                thirdParty, sitekeys);
   }
   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,
   WEBRTC: 256,
+  CSP: 512,
   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"
 });