Issue #347 - TychoAM nsBlocklistService does not support gfxBlacklist

1 files changed, 1666 insertions, 0 deletions

diff --git a/toolkit/components/blocklist/nsBlocklistService.js b/toolkit/components/blocklist/nsBlocklistService.js
new file mode 100644
index 000000000..891346b72
--- /dev/null
+++ b/toolkit/components/blocklist/nsBlocklistService.js
@@ -0,0 +1,1666 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cr = Components.results;
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+Components.utils.import("resource://gre/modules/Services.jsm");
+
+try {
+  // AddonManager.jsm doesn't allow itself to be imported in the child
+  // process. We're used in the child process (for now), so guard against
+  // this.
+  Components.utils.import("resource://gre/modules/AddonManager.jsm");
+  /* globals AddonManagerPrivate*/
+} catch (e) {
+}
+
+XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",
+                                  "resource://gre/modules/FileUtils.jsm");
+#ifdef MOZ_WEBEXTENSIONS
+XPCOMUtils.defineLazyModuleGetter(this, "UpdateUtils",
+                                  "resource://gre/modules/UpdateUtils.jsm");
+#else
+XPCOMUtils.defineLazyModuleGetter(this, "UpdateChannel",
+                                  "resource://gre/modules/UpdateChannel.jsm");
+#endif
+XPCOMUtils.defineLazyModuleGetter(this, "OS",
+                                  "resource://gre/modules/osfile.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "ServiceRequest",
+                                  "resource://gre/modules/ServiceRequest.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Task",
+                                  "resource://gre/modules/Task.jsm");
+
+const TOOLKIT_ID                      = "toolkit@mozilla.org";
+const KEY_PROFILEDIR                  = "ProfD";
+const KEY_APPDIR                      = "XCurProcD";
+const FILE_BLOCKLIST                  = "blocklist.xml";
+const PREF_BLOCKLIST_LASTUPDATETIME   = "app.update.lastUpdateTime.blocklist-background-update-timer";
+const PREF_BLOCKLIST_URL              = "extensions.blocklist.url";
+const PREF_BLOCKLIST_ITEM_URL         = "extensions.blocklist.itemURL";
+const PREF_BLOCKLIST_ENABLED          = "extensions.blocklist.enabled";
+const PREF_BLOCKLIST_INTERVAL         = "extensions.blocklist.interval";
+const PREF_BLOCKLIST_LEVEL            = "extensions.blocklist.level";
+const PREF_BLOCKLIST_PINGCOUNTTOTAL   = "extensions.blocklist.pingCountTotal";
+const PREF_BLOCKLIST_PINGCOUNTVERSION = "extensions.blocklist.pingCountVersion";
+const PREF_BLOCKLIST_SUPPRESSUI       = "extensions.blocklist.suppressUI";
+const PREF_ONECRL_VIA_AMO             = "security.onecrl.via.amo";
+const PREF_BLOCKLIST_UPDATE_ENABLED   = "services.blocklist.update_enabled";
+const PREF_GENERAL_USERAGENT_LOCALE   = "general.useragent.locale";
+const PREF_APP_DISTRIBUTION           = "distribution.id";
+const PREF_APP_DISTRIBUTION_VERSION   = "distribution.version";
+const PREF_EM_LOGGING_ENABLED         = "extensions.logging.enabled";
+const XMLURI_BLOCKLIST                = "http://www.mozilla.org/2006/addons-blocklist";
+const XMLURI_PARSE_ERROR              = "http://www.mozilla.org/newlayout/xml/parsererror.xml"
+const UNKNOWN_XPCOM_ABI               = "unknownABI";
+const URI_BLOCKLIST_DIALOG            = "chrome://mozapps/content/extensions/blocklist.xul"
+const DEFAULT_SEVERITY                = 3;
+const DEFAULT_LEVEL                   = 2;
+const MAX_BLOCK_LEVEL                 = 3;
+const SEVERITY_OUTDATED               = 0;
+const VULNERABILITYSTATUS_NONE             = 0;
+const VULNERABILITYSTATUS_UPDATE_AVAILABLE = 1;
+const VULNERABILITYSTATUS_NO_UPDATE        = 2;
+
+const EXTENSION_BLOCK_FILTERS = ["id", "name", "creator", "homepageURL", "updateURL"];
+
+var gLoggingEnabled = null;
+var gBlocklistEnabled = true;
+var gBlocklistLevel = DEFAULT_LEVEL;
+
+XPCOMUtils.defineLazyServiceGetter(this, "gConsole",
+                                   "@mozilla.org/consoleservice;1",
+                                   "nsIConsoleService");
+
+XPCOMUtils.defineLazyServiceGetter(this, "gVersionChecker",
+                                   "@mozilla.org/xpcom/version-comparator;1",
+                                   "nsIVersionComparator");
+
+XPCOMUtils.defineLazyServiceGetter(this, "gCertBlocklistService",
+                                   "@mozilla.org/security/certblocklist;1",
+                                   "nsICertBlocklist");
+
+XPCOMUtils.defineLazyGetter(this, "gPref", function() {
+  return Cc["@mozilla.org/preferences-service;1"].getService(Ci.nsIPrefService).
+         QueryInterface(Ci.nsIPrefBranch);
+});
+
+// From appinfo in Services.jsm. It is not possible to use the one in
+// Services.jsm since it will not successfully QueryInterface nsIXULAppInfo in
+// xpcshell tests due to other code calling Services.appinfo before the
+// nsIXULAppInfo is created by the tests.
+XPCOMUtils.defineLazyGetter(this, "gApp", function() {
+  let appinfo = Cc["@mozilla.org/xre/app-info;1"]
+                  .getService(Ci.nsIXULRuntime);
+  try {
+    appinfo.QueryInterface(Ci.nsIXULAppInfo);
+  } catch (ex) {
+    // Not all applications implement nsIXULAppInfo (e.g. xpcshell doesn't).
+    if (!(ex instanceof Components.Exception) ||
+        ex.result != Cr.NS_NOINTERFACE)
+      throw ex;
+  }
+  return appinfo;
+});
+
+XPCOMUtils.defineLazyGetter(this, "gABI", function() {
+  let abi = null;
+  try {
+    abi = gApp.XPCOMABI;
+  }
+  catch (e) {
+    LOG("BlockList Global gABI: XPCOM ABI unknown.");
+  }
+
+#ifdef XP_MACOSX
+  // Mac universal build should report a different ABI than either macppc
+  // or mactel.
+  let macutils = Cc["@mozilla.org/xpcom/mac-utils;1"].
+                 getService(Ci.nsIMacUtils);
+
+  if (macutils.isUniversalBinary)
+    abi += "-u-" + macutils.architecturesInBinary;
+#endif
+  return abi;
+});
+
+XPCOMUtils.defineLazyGetter(this, "gOSVersion", function() {
+  let osVersion;
+  let sysInfo = Cc["@mozilla.org/system-info;1"].
+                getService(Ci.nsIPropertyBag2);
+  try {
+    osVersion = sysInfo.getProperty("name") + " " + sysInfo.getProperty("version");
+  }
+  catch (e) {
+    LOG("BlockList Global gOSVersion: OS Version unknown.");
+  }
+
+  if (osVersion) {
+    try {
+      osVersion += " (" + sysInfo.getProperty("secondaryLibrary") + ")";
+    }
+    catch (e) {
+      // Not all platforms have a secondary widget library, so an error is nothing to worry about.
+    }
+    osVersion = encodeURIComponent(osVersion);
+  }
+  return osVersion;
+});
+
+// shared code for suppressing bad cert dialogs
+XPCOMUtils.defineLazyGetter(this, "gCertUtils", function() {
+  let temp = { };
+  Components.utils.import("resource://gre/modules/CertUtils.jsm", temp);
+  return temp;
+});
+
+/**
+ * Logs a string to the error console.
+ * @param   string
+ *          The string to write to the error console..
+ */
+function LOG(string) {
+  if (gLoggingEnabled) {
+    dump("*** " + string + "\n");
+    gConsole.logStringMessage(string);
+  }
+}
+
+/**
+ * Gets a preference value, handling the case where there is no default.
+ * @param   func
+ *          The name of the preference function to call, on nsIPrefBranch
+ * @param   preference
+ *          The name of the preference
+ * @param   defaultValue
+ *          The default value to return in the event the preference has
+ *          no setting
+ * @returns The value of the preference, or undefined if there was no
+ *          user or default value.
+ */
+function getPref(func, preference, defaultValue) {
+  try {
+    return gPref[func](preference);
+  }
+  catch (e) {
+  }
+  return defaultValue;
+}
+
+/**
+ * Constructs a URI to a spec.
+ * @param   spec
+ *          The spec to construct a URI to
+ * @returns The nsIURI constructed.
+ */
+function newURI(spec) {
+  var ioServ = Cc["@mozilla.org/network/io-service;1"].
+               getService(Ci.nsIIOService);
+  return ioServ.newURI(spec, null, null);
+}
+
+// Restarts the application checking in with observers first
+function restartApp() {
+  // Notify all windows that an application quit has been requested.
+  var os = Cc["@mozilla.org/observer-service;1"].
+           getService(Ci.nsIObserverService);
+  var cancelQuit = Cc["@mozilla.org/supports-PRBool;1"].
+                   createInstance(Ci.nsISupportsPRBool);
+  os.notifyObservers(cancelQuit, "quit-application-requested", null);
+
+  // Something aborted the quit process.
+  if (cancelQuit.data)
+    return;
+
+  var as = Cc["@mozilla.org/toolkit/app-startup;1"].
+           getService(Ci.nsIAppStartup);
+  as.quit(Ci.nsIAppStartup.eRestart | Ci.nsIAppStartup.eAttemptQuit);
+}
+
+/**
+ * Checks whether this blocklist element is valid for the current OS and ABI.
+ * If the element has an "os" attribute then the current OS must appear in
+ * its comma separated list for the element to be valid. Similarly for the
+ * xpcomabi attribute.
+ */
+function matchesOSABI(blocklistElement) {
+  if (blocklistElement.hasAttribute("os")) {
+    var choices = blocklistElement.getAttribute("os").split(",");
+    if (choices.length > 0 && choices.indexOf(gApp.OS) < 0)
+      return false;
+  }
+
+  if (blocklistElement.hasAttribute("xpcomabi")) {
+    choices = blocklistElement.getAttribute("xpcomabi").split(",");
+    if (choices.length > 0 && choices.indexOf(gApp.XPCOMABI) < 0)
+      return false;
+  }
+
+  return true;
+}
+
+/**
+ * Gets the current value of the locale.  It's possible for this preference to
+ * be localized, so we have to do a little extra work here.  Similar code
+ * exists in nsHttpHandler.cpp when building the UA string.
+ */
+function getLocale() {
+  try {
+      // Get the default branch
+      var defaultPrefs = gPref.getDefaultBranch(null);
+      return defaultPrefs.getComplexValue(PREF_GENERAL_USERAGENT_LOCALE,
+                                          Ci.nsIPrefLocalizedString).data;
+  } catch (e) {}
+
+  return gPref.getCharPref(PREF_GENERAL_USERAGENT_LOCALE);
+}
+
+/* Get the distribution pref values, from defaults only */
+function getDistributionPrefValue(aPrefName) {
+  var prefValue = "default";
+
+  var defaults = gPref.getDefaultBranch(null);
+  try {
+    prefValue = defaults.getCharPref(aPrefName);
+  } catch (e) {
+    // use default when pref not found
+  }
+
+  return prefValue;
+}
+
+/**
+ * Parse a string representation of a regular expression. Needed because we
+ * use the /pattern/flags form (because it's detectable), which is only
+ * supported as a literal in JS.
+ *
+ * @param  aStr
+ *         String representation of regexp
+ * @return RegExp instance
+ */
+function parseRegExp(aStr) {
+  let lastSlash = aStr.lastIndexOf("/");
+  let pattern = aStr.slice(1, lastSlash);
+  let flags = aStr.slice(lastSlash + 1);
+  return new RegExp(pattern, flags);
+}
+
+/**
+ * Manages the Blocklist. The Blocklist is a representation of the contents of
+ * blocklist.xml and allows us to remotely disable / re-enable blocklisted
+ * items managed by the Extension Manager with an item's appDisabled property.
+ * It also blocklists plugins with data from blocklist.xml.
+ */
+
+function Blocklist() {
+  Services.obs.addObserver(this, "xpcom-shutdown", false);
+  Services.obs.addObserver(this, "sessionstore-windows-restored", false);
+  gLoggingEnabled = getPref("getBoolPref", PREF_EM_LOGGING_ENABLED, false);
+  gBlocklistEnabled = getPref("getBoolPref", PREF_BLOCKLIST_ENABLED, true);
+  gBlocklistLevel = Math.min(getPref("getIntPref", PREF_BLOCKLIST_LEVEL, DEFAULT_LEVEL),
+                                     MAX_BLOCK_LEVEL);
+  gPref.addObserver("extensions.blocklist.", this, false);
+  gPref.addObserver(PREF_EM_LOGGING_ENABLED, this, false);
+  this.wrappedJSObject = this;
+  // requests from child processes come in here, see receiveMessage.
+  Services.ppmm.addMessageListener("Blocklist:getPluginBlocklistState", this);
+  Services.ppmm.addMessageListener("Blocklist:content-blocklist-updated", this);
+}
+
+Blocklist.prototype = {
+  /**
+   * Extension ID -> array of Version Ranges
+   * Each value in the version range array is a JS Object that has the
+   * following properties:
+   *   "minVersion"  The minimum version in a version range (default = 0)
+   *   "maxVersion"  The maximum version in a version range (default = *)
+   *   "targetApps"  Application ID -> array of Version Ranges
+   *                 (default = current application ID)
+   *                 Each value in the version range array is a JS Object that
+   *                 has the following properties:
+   *                   "minVersion"  The minimum version in a version range
+   *                                 (default = 0)
+   *                   "maxVersion"  The maximum version in a version range
+   *                                 (default = *)
+   */
+  _addonEntries: null,
+  _gfxEntries: null,
+  _pluginEntries: null,
+
+  shutdown: function() {
+    Services.obs.removeObserver(this, "xpcom-shutdown");
+    Services.ppmm.removeMessageListener("Blocklist:getPluginBlocklistState", this);
+    Services.ppmm.removeMessageListener("Blocklist:content-blocklist-updated", this);
+    gPref.removeObserver("extensions.blocklist.", this);
+    gPref.removeObserver(PREF_EM_LOGGING_ENABLED, this);
+  },
+
+  observe: function(aSubject, aTopic, aData) {
+    switch (aTopic) {
+    case "xpcom-shutdown":
+      this.shutdown();
+      break;
+    case "nsPref:changed":
+      switch (aData) {
+        case PREF_EM_LOGGING_ENABLED:
+          gLoggingEnabled = getPref("getBoolPref", PREF_EM_LOGGING_ENABLED, false);
+          break;
+        case PREF_BLOCKLIST_ENABLED:
+          gBlocklistEnabled = getPref("getBoolPref", PREF_BLOCKLIST_ENABLED, true);
+          this._loadBlocklist();
+          this._blocklistUpdated(null, null);
+          break;
+        case PREF_BLOCKLIST_LEVEL:
+          gBlocklistLevel = Math.min(getPref("getIntPref", PREF_BLOCKLIST_LEVEL, DEFAULT_LEVEL),
+                                     MAX_BLOCK_LEVEL);
+          this._blocklistUpdated(null, null);
+          break;
+      }
+      break;
+    case "sessionstore-windows-restored":
+      Services.obs.removeObserver(this, "sessionstore-windows-restored");
+      this._preloadBlocklist();
+      break;
+    }
+  },
+
+  // Message manager message handlers
+  receiveMessage: function(aMsg) {
+    switch (aMsg.name) {
+      case "Blocklist:getPluginBlocklistState":
+        return this.getPluginBlocklistState(aMsg.data.addonData,
+                                            aMsg.data.appVersion,
+                                            aMsg.data.toolkitVersion);
+      case "Blocklist:content-blocklist-updated":
+        Services.obs.notifyObservers(null, "content-blocklist-updated", null);
+        break;
+      default:
+        throw new Error("Unknown blocklist message received from content: " + aMsg.name);
+    }
+    return undefined;
+  },
+
+  /* See nsIBlocklistService */
+  isAddonBlocklisted: function(addon, appVersion, toolkitVersion) {
+    return this.getAddonBlocklistState(addon, appVersion, toolkitVersion) ==
+                   Ci.nsIBlocklistService.STATE_BLOCKED;
+  },
+
+  /* See nsIBlocklistService */
+  getAddonBlocklistState: function(addon, appVersion, toolkitVersion) {
+    if (!this._isBlocklistLoaded())
+      this._loadBlocklist();
+    return this._getAddonBlocklistState(addon, this._addonEntries,
+                                        appVersion, toolkitVersion);
+  },
+
+  /**
+   * Private version of getAddonBlocklistState that allows the caller to pass in
+   * the add-on blocklist entries to compare against.
+   *
+   * @param   id
+   *          The ID of the item to get the blocklist state for.
+   * @param   version
+   *          The version of the item to get the blocklist state for.
+   * @param   addonEntries
+   *          The add-on blocklist entries to compare against.
+   * @param   appVersion
+   *          The application version to compare to, will use the current
+   *          version if null.
+   * @param   toolkitVersion
+   *          The toolkit version to compare to, will use the current version if
+   *          null.
+   * @returns The blocklist state for the item, one of the STATE constants as
+   *          defined in nsIBlocklistService.
+   */
+  _getAddonBlocklistState: function(addon, addonEntries, appVersion, toolkitVersion) {
+    if (!gBlocklistEnabled)
+      return Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
+
+    // Not all applications implement nsIXULAppInfo (e.g. xpcshell doesn't).
+    if (!appVersion && !gApp.version)
+      return Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
+
+    if (!appVersion)
+      appVersion = gApp.version;
+    if (!toolkitVersion)
+      toolkitVersion = gApp.platformVersion;
+
+    var blItem = this._findMatchingAddonEntry(addonEntries, addon);
+    if (!blItem)
+      return Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
+
+    for (let currentblItem of blItem.versions) {
+      if (currentblItem.includesItem(addon.version, appVersion, toolkitVersion))
+        return currentblItem.severity >= gBlocklistLevel ? Ci.nsIBlocklistService.STATE_BLOCKED :
+                                                       Ci.nsIBlocklistService.STATE_SOFTBLOCKED;
+    }
+    return Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
+  },
+
+  /**
+   * Returns the set of prefs of the add-on stored in the blocklist file
+   * (probably to revert them on disabling).
+   * @param addon
+   *        The add-on whose to-be-reset prefs are to be found.
+   */
+  _getAddonPrefs: function(addon) {
+    let entry = this._findMatchingAddonEntry(this._addonEntries, addon);
+    return entry.prefs.slice(0);
+  },
+
+  _findMatchingAddonEntry: function(aAddonEntries, aAddon) {
+    if (!aAddon)
+      return null;
+    // Returns true if the params object passes the constraints set by entry.
+    // (For every non-null property in entry, the same key must exist in
+    // params and value must be the same)
+    function checkEntry(entry, params) {
+      for (let [key, value] of entry) {
+        if (value === null || value === undefined)
+          continue;
+        if (params[key]) {
+          if (value instanceof RegExp) {
+            if (!value.test(params[key])) {
+              return false;
+            }
+          } else if (value !== params[key]) {
+            return false;
+          }
+        } else {
+          return false;
+        }
+      }
+      return true;
+    }
+
+    let params = {};
+    for (let filter of EXTENSION_BLOCK_FILTERS) {
+      params[filter] = aAddon[filter];
+    }
+    if (params.creator)
+      params.creator = params.creator.name;
+    for (let entry of aAddonEntries) {
+      if (checkEntry(entry.attributes, params)) {
+         return entry;
+       }
+     }
+     return null;
+  },
+
+  /* See nsIBlocklistService */
+  getAddonBlocklistURL: function(addon, appVersion, toolkitVersion) {
+    if (!gBlocklistEnabled)
+      return "";
+
+    if (!this._isBlocklistLoaded())
+      this._loadBlocklist();
+
+    let blItem = this._findMatchingAddonEntry(this._addonEntries, addon);
+    if (!blItem || !blItem.blockID)
+      return null;
+
+    return this._createBlocklistURL(blItem.blockID);
+  },
+
+  _createBlocklistURL: function(id) {
+    let url = Services.urlFormatter.formatURLPref(PREF_BLOCKLIST_ITEM_URL);
+    url = url.replace(/%blockID%/g, id);
+
+    return url;
+  },
+
+  notify: function(aTimer) {
+    if (!gBlocklistEnabled)
+      return;
+
+    try {
+      var dsURI = gPref.getCharPref(PREF_BLOCKLIST_URL);
+    }
+    catch (e) {
+      LOG("Blocklist::notify: The " + PREF_BLOCKLIST_URL + " preference" +
+          " is missing!");
+      return;
+    }
+
+    var pingCountVersion = getPref("getIntPref", PREF_BLOCKLIST_PINGCOUNTVERSION, 0);
+    var pingCountTotal = getPref("getIntPref", PREF_BLOCKLIST_PINGCOUNTTOTAL, 1);
+    var daysSinceLastPing = 0;
+    if (pingCountVersion == 0) {
+      daysSinceLastPing = "new";
+    }
+    else {
+      // Seconds in one day is used because nsIUpdateTimerManager stores the
+      // last update time in seconds.
+      let secondsInDay = 60 * 60 * 24;
+      let lastUpdateTime = getPref("getIntPref", PREF_BLOCKLIST_LASTUPDATETIME, 0);
+      if (lastUpdateTime == 0) {
+        daysSinceLastPing = "invalid";
+      }
+      else {
+        let now = Math.round(Date.now() / 1000);
+        daysSinceLastPing = Math.floor((now - lastUpdateTime) / secondsInDay);
+      }
+
+      if (daysSinceLastPing == 0 || daysSinceLastPing == "invalid") {
+        pingCountVersion = pingCountTotal = "invalid";
+      }
+    }
+
+    if (pingCountVersion < 1)
+      pingCountVersion = 1;
+    if (pingCountTotal < 1)
+      pingCountTotal = 1;
+
+    dsURI = dsURI.replace(/%APP_ID%/g, gApp.ID);
+    // Not all applications implement nsIXULAppInfo (e.g. xpcshell doesn't).
+    if (gApp.version)
+      dsURI = dsURI.replace(/%APP_VERSION%/g, gApp.version);
+    dsURI = dsURI.replace(/%PRODUCT%/g, gApp.name);
+    // Not all applications implement nsIXULAppInfo (e.g. xpcshell doesn't).
+    if (gApp.version)
+      dsURI = dsURI.replace(/%VERSION%/g, gApp.version);
+    dsURI = dsURI.replace(/%BUILD_ID%/g, gApp.appBuildID);
+    dsURI = dsURI.replace(/%BUILD_TARGET%/g, gApp.OS + "_" + gABI);
+    dsURI = dsURI.replace(/%OS_VERSION%/g, gOSVersion);
+    dsURI = dsURI.replace(/%LOCALE%/g, getLocale());
+#ifdef MOZ_WEBEXTENSIONS
+    dsURI = dsURI.replace(/%CHANNEL%/g, UpdateUtils.UpdateChannel);
+#else
+    dsURI = dsURI.replace(/%CHANNEL%/g, UpdateChannel.get());
+#endif
+    dsURI = dsURI.replace(/%PLATFORM_VERSION%/g, gApp.platformVersion);
+    dsURI = dsURI.replace(/%DISTRIBUTION%/g,
+                      getDistributionPrefValue(PREF_APP_DISTRIBUTION));
+    dsURI = dsURI.replace(/%DISTRIBUTION_VERSION%/g,
+                      getDistributionPrefValue(PREF_APP_DISTRIBUTION_VERSION));
+    dsURI = dsURI.replace(/%PING_COUNT%/g, pingCountVersion);
+    dsURI = dsURI.replace(/%TOTAL_PING_COUNT%/g, pingCountTotal);
+    dsURI = dsURI.replace(/%DAYS_SINCE_LAST_PING%/g, daysSinceLastPing);
+    dsURI = dsURI.replace(/\+/g, "%2B");
+
+    // Under normal operations it will take around 5,883,516 years before the
+    // preferences used to store pingCountVersion and pingCountTotal will rollover
+    // so this code doesn't bother trying to do the "right thing" here.
+    if (pingCountVersion != "invalid") {
+      pingCountVersion++;
+      if (pingCountVersion > 2147483647) {
+        // Rollover to -1 if the value is greater than what is support by an
+        // integer preference. The -1 indicates that the counter has been reset.
+        pingCountVersion = -1;
+      }
+      gPref.setIntPref(PREF_BLOCKLIST_PINGCOUNTVERSION, pingCountVersion);
+    }
+
+    if (pingCountTotal != "invalid") {
+      pingCountTotal++;
+      if (pingCountTotal > 2147483647) {
+        // Rollover to 1 if the value is greater than what is support by an
+        // integer preference.
+        pingCountTotal = -1;
+      }
+      gPref.setIntPref(PREF_BLOCKLIST_PINGCOUNTTOTAL, pingCountTotal);
+    }
+
+    // Verify that the URI is valid
+    try {
+      var uri = newURI(dsURI);
+    }
+    catch (e) {
+      LOG("Blocklist::notify: There was an error creating the blocklist URI\r\n" +
+          "for: " + dsURI + ", error: " + e);
+      return;
+    }
+
+    LOG("Blocklist::notify: Requesting " + uri.spec);
+    let request = new ServiceRequest();
+    request.open("GET", uri.spec, true);
+    request.channel.notificationCallbacks = new gCertUtils.BadCertHandler();
+    request.overrideMimeType("text/xml");
+    request.setRequestHeader("Cache-Control", "no-cache");
+    request.QueryInterface(Components.interfaces.nsIJSXMLHttpRequest);
+
+    request.addEventListener("error", event => this.onXMLError(event), false);
+    request.addEventListener("load", event => this.onXMLLoad(event), false);
+    request.send(null);
+
+    // When the blocklist loads we need to compare it to the current copy so
+    // make sure we have loaded it.
+    if (!this._isBlocklistLoaded())
+      this._loadBlocklist();
+  },
+
+  onXMLLoad: Task.async(function*(aEvent) {
+    let request = aEvent.target;
+    try {
+      gCertUtils.checkCert(request.channel);
+    }
+    catch (e) {
+      LOG("Blocklist::onXMLLoad: " + e);
+      return;
+    }
+    let responseXML = request.responseXML;
+    if (!responseXML || responseXML.documentElement.namespaceURI == XMLURI_PARSE_ERROR ||
+        (request.status != 200 && request.status != 0)) {
+      LOG("Blocklist::onXMLLoad: there was an error during load");
+      return;
+    }
+
+    var oldAddonEntries = this._addonEntries;
+    var oldPluginEntries = this._pluginEntries;
+    this._addonEntries = [];
+    this._gfxEntries = [];
+    this._pluginEntries = [];
+
+    this._loadBlocklistFromString(request.responseText);
+    // We don't inform the users when the graphics blocklist changed at runtime.
+    // However addons and plugins blocking status is refreshed.
+    this._blocklistUpdated(oldAddonEntries, oldPluginEntries);
+
+    try {
+      let path = OS.Path.join(OS.Constants.Path.profileDir, FILE_BLOCKLIST);
+      yield OS.File.writeAtomic(path, request.responseText, {tmpPath: path + ".tmp"});
+    } catch (e) {
+      LOG("Blocklist::onXMLLoad: " + e);
+    }
+  }),
+
+  onXMLError: function(aEvent) {
+    try {
+      var request = aEvent.target;
+      // the following may throw (e.g. a local file or timeout)
+      var status = request.status;
+    }
+    catch (e) {
+      request = aEvent.target.channel.QueryInterface(Ci.nsIRequest);
+      status = request.status;
+    }
+    var statusText = "nsIXMLHttpRequest channel unavailable";
+    // When status is 0 we don't have a valid channel.
+    if (status != 0) {
+      try {
+        statusText = request.statusText;
+      } catch (e) {
+      }
+    }
+    LOG("Blocklist:onError: There was an error loading the blocklist file\r\n" +
+        statusText);
+  },
+
+  /**
+   * Finds the newest blocklist file from the application and the profile and
+   * load it or does nothing if neither exist.
+   */
+  _loadBlocklist: function() {
+    this._addonEntries = [];
+    this._gfxEntries = [];
+    this._pluginEntries = [];
+    var profFile = FileUtils.getFile(KEY_PROFILEDIR, [FILE_BLOCKLIST]);
+    if (profFile.exists()) {
+      this._loadBlocklistFromFile(profFile);
+      return;
+    }
+    var appFile = FileUtils.getFile(KEY_APPDIR, [FILE_BLOCKLIST]);
+    if (appFile.exists()) {
+      this._loadBlocklistFromFile(appFile);
+      return;
+    }
+    LOG("Blocklist::_loadBlocklist: no XML File found");
+  },
+
+  /**
+#    The blocklist XML file looks something like this:
+#
+#    <blocklist xmlns="http://www.mozilla.org/2006/addons-blocklist">
+#      <emItems>
+#        <emItem id="item_1@domain" blockID="i1">
+#          <prefs>
+#            <pref>accessibility.accesskeycausesactivation</pref>
+#            <pref>accessibility.blockautorefresh</pref>
+#          </prefs>
+#          <versionRange minVersion="1.0" maxVersion="2.0.*">
+#            <targetApplication id="{ec8030f7-c20a-464f-9b0e-13a3a9e97384}">
+#              <versionRange minVersion="1.5" maxVersion="1.5.*"/>
+#              <versionRange minVersion="1.7" maxVersion="1.7.*"/>
+#            </targetApplication>
+#            <targetApplication id="toolkit@mozilla.org">
+#              <versionRange minVersion="1.9" maxVersion="1.9.*"/>
+#            </targetApplication>
+#          </versionRange>
+#          <versionRange minVersion="3.0" maxVersion="3.0.*">
+#            <targetApplication id="{ec8030f7-c20a-464f-9b0e-13a3a9e97384}">
+#              <versionRange minVersion="1.5" maxVersion="1.5.*"/>
+#            </targetApplication>
+#            <targetApplication id="toolkit@mozilla.org">
+#              <versionRange minVersion="1.9" maxVersion="1.9.*"/>
+#            </targetApplication>
+#          </versionRange>
+#        </emItem>
+#        <emItem id="item_2@domain" blockID="i2">
+#          <versionRange minVersion="3.1" maxVersion="4.*"/>
+#        </emItem>
+#        <emItem id="item_3@domain">
+#          <versionRange>
+#            <targetApplication id="{ec8030f7-c20a-464f-9b0e-13a3a9e97384}">
+#              <versionRange minVersion="1.5" maxVersion="1.5.*"/>
+#            </targetApplication>
+#          </versionRange>
+#        </emItem>
+#        <emItem id="item_4@domain" blockID="i3">
+#          <versionRange>
+#            <targetApplication>
+#              <versionRange minVersion="1.5" maxVersion="1.5.*"/>
+#            </targetApplication>
+#          </versionRange>
+#        <emItem id="/@badperson\.com$/"/>
+#      </emItems>
+#      <pluginItems>
+#        <pluginItem blockID="i4">
+#          <!-- All match tags must match a plugin to blocklist a plugin -->
+#          <match name="name" exp="some plugin"/>
+#          <match name="description" exp="1[.]2[.]3"/>
+#        </pluginItem>
+#      </pluginItems>
+#      <certItems>
+#        <!-- issuerName is the DER issuer name data base64 encoded... -->
+#        <certItem issuerName="MA0xCzAJBgNVBAMMAmNh">
+#          <!-- ... as is the serial number DER data -->
+#          <serialNumber>AkHVNA==</serialNumber>
+#        </certItem>
+#        <!-- subject is the DER subject name data base64 encoded... -->
+#        <certItem subject="MA0xCzAJBgNVBAMMAmNh" pubKeyHash="/xeHA5s+i9/z9d8qy6JEuE1xGoRYIwgJuTE/lmaGJ7M=">
+#        </certItem>
+#      </certItems>
+#    </blocklist>
+   */
+
+  _loadBlocklistFromFile: function(file) {
+    if (!gBlocklistEnabled) {
+      LOG("Blocklist::_loadBlocklistFromFile: blocklist is disabled");
+      return;
+    }
+
+    let telemetry = Services.telemetry;
+
+    if (this._isBlocklistPreloaded()) {
+      telemetry.getHistogramById("BLOCKLIST_SYNC_FILE_LOAD").add(false);
+      this._loadBlocklistFromString(this._preloadedBlocklistContent);
+      delete this._preloadedBlocklistContent;
+      return;
+    }
+
+    if (!file.exists()) {
+      LOG("Blocklist::_loadBlocklistFromFile: XML File does not exist " + file.path);
+      return;
+    }
+
+    telemetry.getHistogramById("BLOCKLIST_SYNC_FILE_LOAD").add(true);
+
+    let text = "";
+    let fstream = null;
+    let cstream = null;
+
+    try {
+      fstream = Components.classes["@mozilla.org/network/file-input-stream;1"]
+                          .createInstance(Components.interfaces.nsIFileInputStream);
+      cstream = Components.classes["@mozilla.org/intl/converter-input-stream;1"]
+                          .createInstance(Components.interfaces.nsIConverterInputStream);
+
+      fstream.init(file, FileUtils.MODE_RDONLY, FileUtils.PERMS_FILE, 0);
+      cstream.init(fstream, "UTF-8", 0, 0);
+
+      let str = {};
+      let read = 0;
+
+      do {
+        read = cstream.readString(0xffffffff, str); // read as much as we can and put it in str.value
+        text += str.value;
+      } while (read != 0);
+    } catch (e) {
+      LOG("Blocklist::_loadBlocklistFromFile: Failed to load XML file " + e);
+    } finally {
+      if (cstream)
+        cstream.close();
+      if (fstream)
+        fstream.close();
+    }
+
+    if (text)
+        this._loadBlocklistFromString(text);
+  },
+
+  _isBlocklistLoaded: function() {
+    return this._addonEntries != null && this._gfxEntries != null && this._pluginEntries != null;
+  },
+
+  _isBlocklistPreloaded: function() {
+    return this._preloadedBlocklistContent != null;
+  },
+
+  /* Used for testing */
+  _clear: function() {
+    this._addonEntries = null;
+    this._gfxEntries = null;
+    this._pluginEntries = null;
+    this._preloadedBlocklistContent = null;
+  },
+
+  _preloadBlocklist: Task.async(function*() {
+    let profPath = OS.Path.join(OS.Constants.Path.profileDir, FILE_BLOCKLIST);
+    try {
+      yield this._preloadBlocklistFile(profPath);
+      return;
+    } catch (e) {
+      LOG("Blocklist::_preloadBlocklist: Failed to load XML file " + e)
+    }
+
+    var appFile = FileUtils.getFile(KEY_APPDIR, [FILE_BLOCKLIST]);
+    try {
+      yield this._preloadBlocklistFile(appFile.path);
+      return;
+    } catch (e) {
+      LOG("Blocklist::_preloadBlocklist: Failed to load XML file " + e)
+    }
+
+    LOG("Blocklist::_preloadBlocklist: no XML File found");
+  }),
+
+  _preloadBlocklistFile: Task.async(function*(path) {
+    if (this._addonEntries) {
+      // The file has been already loaded.
+      return;
+    }
+
+    if (!gBlocklistEnabled) {
+      LOG("Blocklist::_preloadBlocklistFile: blocklist is disabled");
+      return;
+    }
+
+    let text = yield OS.File.read(path, { encoding: "utf-8" });
+
+    if (!this._addonEntries) {
+      // Store the content only if a sync load has not been performed in the meantime.
+      this._preloadedBlocklistContent = text;
+    }
+  }),
+
+  _loadBlocklistFromString : function(text) {
+    try {
+      var parser = Cc["@mozilla.org/xmlextras/domparser;1"].
+                   createInstance(Ci.nsIDOMParser);
+      var doc = parser.parseFromString(text, "text/xml");
+      if (doc.documentElement.namespaceURI != XMLURI_BLOCKLIST) {
+        LOG("Blocklist::_loadBlocklistFromFile: aborting due to incorrect " +
+            "XML Namespace.\r\nExpected: " + XMLURI_BLOCKLIST + "\r\n" +
+            "Received: " + doc.documentElement.namespaceURI);
+        return;
+      }
+
+      var populateCertBlocklist = getPref("getBoolPref", PREF_ONECRL_VIA_AMO, true);
+
+      var childNodes = doc.documentElement.childNodes;
+      for (let element of childNodes) {
+        if (!(element instanceof Ci.nsIDOMElement))
+          continue;
+        switch (element.localName) {
+        case "emItems":
+          this._addonEntries = this._processItemNodes(element.childNodes, "emItem",
+                                                      this._handleEmItemNode);
+          break;
+        case "pluginItems":
+          this._pluginEntries = this._processItemNodes(element.childNodes, "pluginItem",
+                                                       this._handlePluginItemNode);
+          break;
+        case "certItems":
+          if (populateCertBlocklist) {
+            this._processItemNodes(element.childNodes, "certItem",
+                                   this._handleCertItemNode.bind(this));
+          }
+          break;
+        case "gfxItems":
+          // Parse as simple list of objects.
+          this._gfxEntries = this._processItemNodes(element.childNodes, "gfxBlacklistEntry",
+                                                    this._handleGfxBlacklistNode);
+          break;
+        default:
+          LOG("Blocklist::_loadBlocklistFromString: ignored entries " + element.localName);
+        }
+      }
+      if (populateCertBlocklist) {
+        gCertBlocklistService.saveEntries();
+      }
+      if (this._gfxEntries.length > 0) {
+        this._notifyObserversBlocklistGFX();
+      }
+    }
+    catch (e) {
+      LOG("Blocklist::_loadBlocklistFromFile: Error constructing blocklist " + e);
+      return;
+    }
+  },
+
+  _processItemNodes: function(itemNodes, itemName, handler) {
+    var result = [];
+    for (var i = 0; i < itemNodes.length; ++i) {
+      var blocklistElement = itemNodes.item(i);
+      if (!(blocklistElement instanceof Ci.nsIDOMElement) ||
+          blocklistElement.localName != itemName)
+        continue;
+
+      handler(blocklistElement, result);
+    }
+    return result;
+  },
+
+  _handleCertItemNode: function(blocklistElement, result) {
+    let issuer = blocklistElement.getAttribute("issuerName");
+    if (issuer) {
+      for (let snElement of blocklistElement.children) {
+        try {
+          gCertBlocklistService.revokeCertByIssuerAndSerial(issuer, snElement.textContent);
+        } catch (e) {
+          // we want to keep trying other elements since missing all items
+          // is worse than missing one
+          LOG("Blocklist::_handleCertItemNode: Error adding revoked cert by Issuer and Serial" + e);
+        }
+      }
+      return;
+    }
+
+    let pubKeyHash = blocklistElement.getAttribute("pubKeyHash");
+    let subject = blocklistElement.getAttribute("subject");
+
+    if (pubKeyHash && subject) {
+      try {
+        gCertBlocklistService.revokeCertBySubjectAndPubKey(subject, pubKeyHash);
+      } catch (e) {
+        LOG("Blocklist::_handleCertItemNode: Error adding revoked cert by Subject and PubKey" + e);
+      }
+    }
+  },
+
+  _handleEmItemNode: function(blocklistElement, result) {
+    if (!matchesOSABI(blocklistElement))
+      return;
+
+    let blockEntry = {
+      versions: [],
+      prefs: [],
+      blockID: null,
+      attributes: new Map()
+      // Atleast one of EXTENSION_BLOCK_FILTERS must get added to attributes
+    };
+
+    // Any filter starting with '/' is interpreted as a regex. So if an attribute
+    // starts with a '/' it must be checked via a regex.
+    function regExpCheck(attr) {
+      return attr.startsWith("/") ? parseRegExp(attr) : attr;
+    }
+
+    for (let filter of EXTENSION_BLOCK_FILTERS) {
+      let attr = blocklistElement.getAttribute(filter);
+      if (attr)
+        blockEntry.attributes.set(filter, regExpCheck(attr));
+    }
+
+    var childNodes = blocklistElement.childNodes;
+
+    for (let x = 0; x < childNodes.length; x++) {
+      var childElement = childNodes.item(x);
+      if (!(childElement instanceof Ci.nsIDOMElement))
+        continue;
+      if (childElement.localName === "prefs") {
+        let prefElements = childElement.childNodes;
+        for (let i = 0; i < prefElements.length; i++) {
+          let prefElement = prefElements.item(i);
+          if (!(prefElement instanceof Ci.nsIDOMElement) ||
+              prefElement.localName !== "pref")
+            continue;
+          blockEntry.prefs.push(prefElement.textContent);
+        }
+      }
+      else if (childElement.localName === "versionRange")
+        blockEntry.versions.push(new BlocklistItemData(childElement));
+    }
+    // if only the extension ID is specified block all versions of the
+    // extension for the current application.
+    if (blockEntry.versions.length == 0)
+      blockEntry.versions.push(new BlocklistItemData(null));
+
+    blockEntry.blockID = blocklistElement.getAttribute("blockID");
+
+    result.push(blockEntry);
+  },
+
+  _handlePluginItemNode: function(blocklistElement, result) {
+    if (!matchesOSABI(blocklistElement))
+      return;
+
+    var matchNodes = blocklistElement.childNodes;
+    var blockEntry = {
+      matches: {},
+      versions: [],
+      blockID: null,
+      infoURL: null,
+    };
+    var hasMatch = false;
+    for (var x = 0; x < matchNodes.length; ++x) {
+      var matchElement = matchNodes.item(x);
+      if (!(matchElement instanceof Ci.nsIDOMElement))
+        continue;
+      if (matchElement.localName == "match") {
+        var name = matchElement.getAttribute("name");
+        var exp = matchElement.getAttribute("exp");
+        try {
+          blockEntry.matches[name] = new RegExp(exp, "m");
+          hasMatch = true;
+        } catch (e) {
+          // Ignore invalid regular expressions
+        }
+      }
+      if (matchElement.localName == "versionRange") {
+        blockEntry.versions.push(new BlocklistItemData(matchElement));
+      }
+      else if (matchElement.localName == "infoURL") {
+        blockEntry.infoURL = matchElement.textContent;
+      }
+    }
+    // Plugin entries require *something* to match to an actual plugin
+    if (!hasMatch)
+      return;
+    // Add a default versionRange if there wasn't one specified
+    if (blockEntry.versions.length == 0)
+      blockEntry.versions.push(new BlocklistItemData(null));
+
+    blockEntry.blockID = blocklistElement.getAttribute("blockID");
+
+    result.push(blockEntry);
+  },
+
+  // <gfxBlacklistEntry blockID="g60">
+  //   <os>WINNT 6.0</os>
+  //   <osversion>14</osversion> currently only used for Android
+  //   <versionRange minVersion="42.0" maxVersion="13.0b2"/>
+  //   <vendor>0x8086</vendor>
+  //   <devices>
+  //     <device>0x2582</device>
+  //     <device>0x2782</device>
+  //   </devices>
+  //   <feature> DIRECT3D_10_LAYERS </feature>
+  //   <featureStatus> BLOCKED_DRIVER_VERSION </featureStatus>
+  //   <driverVersion> 8.52.322.2202 </driverVersion>
+  //   <driverVersionMax> 8.52.322.2202 </driverVersionMax>
+  //   <driverVersionComparator> LESS_THAN_OR_EQUAL </driverVersionComparator>
+  //   <model>foo</model>
+  //   <product>foo</product>
+  //   <manufacturer>foo</manufacturer>
+  //   <hardware>foo</hardware>
+  // </gfxBlacklistEntry>
+  _handleGfxBlacklistNode: function (blocklistElement, result) {
+    const blockEntry = {};
+
+    // The blockID attribute is always present in the actual data produced on server
+    // (see https://github.com/mozilla/addons-server/blob/2016.05.05/src/olympia/blocklist/templates/blocklist/blocklist.xml#L74)
+    // But it is sometimes missing in test fixtures.
+    if (blocklistElement.hasAttribute("blockID")) {
+      blockEntry.blockID = blocklistElement.getAttribute("blockID");
+    }
+
+    // Trim helper (spaces, tabs, no-break spaces..)
+    const trim = (s) => (s || '').replace(/(^[\s\uFEFF\xA0]+)|([\s\uFEFF\xA0]+$)/g, "");
+
+    for (let i = 0; i < blocklistElement.childNodes.length; ++i) {
+      var matchElement = blocklistElement.childNodes.item(i);
+      if (!(matchElement instanceof Ci.nsIDOMElement))
+        continue;
+
+      let value;
+      if (matchElement.localName == "devices") {
+        value = [];
+        for (let j = 0; j < matchElement.childNodes.length; j++) {
+          const childElement = matchElement.childNodes.item(j);
+          const childValue = trim(childElement.textContent);
+          // Make sure no empty value is added.
+          if (childValue) {
+            if (/,/.test(childValue)) {
+              // Devices can't contain comma.
+              // (c.f serialization in _notifyObserversBlocklistGFX)
+              const e = new Error(`Unsupported device name ${childValue}`);
+              Components.utils.reportError(e);
+            }
+            else {
+              value.push(childValue);
+            }
+          }
+        }
+      } else if (matchElement.localName == "versionRange") {
+        value = {minVersion: trim(matchElement.getAttribute("minVersion")) || "0",
+                 maxVersion: trim(matchElement.getAttribute("maxVersion")) || "*"};
+      } else {
+        value = trim(matchElement.textContent);
+      }
+      if (value) {
+        blockEntry[matchElement.localName] = value;
+      }
+    }
+    result.push(blockEntry);
+  },
+
+  /* See nsIBlocklistService */
+  getPluginBlocklistState: function(plugin, appVersion, toolkitVersion) {
+#ifdef MOZ_WIDGET_ANDROID
+    return Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
+#endif
+    if (!this._isBlocklistLoaded())
+      this._loadBlocklist();
+    return this._getPluginBlocklistState(plugin, this._pluginEntries,
+                                         appVersion, toolkitVersion);
+  },
+
+  /**
+   * Private helper to get the blocklist entry for a plugin given a set of
+   * blocklist entries and versions.
+   *
+   * @param   plugin
+   *          The nsIPluginTag to get the blocklist state for.
+   * @param   pluginEntries
+   *          The plugin blocklist entries to compare against.
+   * @param   appVersion
+   *          The application version to compare to, will use the current
+   *          version if null.
+   * @param   toolkitVersion
+   *          The toolkit version to compare to, will use the current version if
+   *          null.
+   * @returns {entry: blocklistEntry, version: blocklistEntryVersion},
+   *          or null if there is no matching entry.
+   */
+  _getPluginBlocklistEntry: function(plugin, pluginEntries, appVersion, toolkitVersion) {
+    if (!gBlocklistEnabled)
+      return null;
+
+    // Not all applications implement nsIXULAppInfo (e.g. xpcshell doesn't).
+    if (!appVersion && !gApp.version)
+      return Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
+
+    if (!appVersion)
+      appVersion = gApp.version;
+    if (!toolkitVersion)
+      toolkitVersion = gApp.platformVersion;
+
+    for (var blockEntry of pluginEntries) {
+      var matchFailed = false;
+      for (var name in blockEntry.matches) {
+        if (!(name in plugin) ||
+            typeof(plugin[name]) != "string" ||
+            !blockEntry.matches[name].test(plugin[name])) {
+          matchFailed = true;
+          break;
+        }
+      }
+
+      if (matchFailed)
+        continue;
+
+      for (let blockEntryVersion of blockEntry.versions) {
+        if (blockEntryVersion.includesItem(plugin.version, appVersion,
+                                           toolkitVersion)) {
+          return {entry: blockEntry, version: blockEntryVersion};
+        }
+      }
+    }
+
+    return null;
+  },
+
+  /**
+   * Private version of getPluginBlocklistState that allows the caller to pass in
+   * the plugin blocklist entries.
+   *
+   * @param   plugin
+   *          The nsIPluginTag to get the blocklist state for.
+   * @param   pluginEntries
+   *          The plugin blocklist entries to compare against.
+   * @param   appVersion
+   *          The application version to compare to, will use the current
+   *          version if null.
+   * @param   toolkitVersion
+   *          The toolkit version to compare to, will use the current version if
+   *          null.
+   * @returns The blocklist state for the item, one of the STATE constants as
+   *          defined in nsIBlocklistService.
+   */
+  _getPluginBlocklistState: function(plugin, pluginEntries, appVersion, toolkitVersion) {
+
+    let r = this._getPluginBlocklistEntry(plugin, pluginEntries,
+                                          appVersion, toolkitVersion);
+    if (!r) {
+      return Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
+    }
+
+    let {entry: blockEntry, version: blockEntryVersion} = r;
+
+    if (blockEntryVersion.severity >= gBlocklistLevel)
+      return Ci.nsIBlocklistService.STATE_BLOCKED;
+    if (blockEntryVersion.severity == SEVERITY_OUTDATED) {
+      let vulnerabilityStatus = blockEntryVersion.vulnerabilityStatus;
+      if (vulnerabilityStatus == VULNERABILITYSTATUS_UPDATE_AVAILABLE)
+        return Ci.nsIBlocklistService.STATE_VULNERABLE_UPDATE_AVAILABLE;
+      if (vulnerabilityStatus == VULNERABILITYSTATUS_NO_UPDATE)
+        return Ci.nsIBlocklistService.STATE_VULNERABLE_NO_UPDATE;
+      return Ci.nsIBlocklistService.STATE_OUTDATED;
+    }
+    return Ci.nsIBlocklistService.STATE_SOFTBLOCKED;
+  },
+
+  /* See nsIBlocklistService */
+  getPluginBlocklistURL: function(plugin) {
+    if (!this._isBlocklistLoaded())
+      this._loadBlocklist();
+
+    let r = this._getPluginBlocklistEntry(plugin, this._pluginEntries);
+    if (!r) {
+      return null;
+    }
+    let {entry: blockEntry, version: blockEntryVersion} = r;
+    if (!blockEntry.blockID) {
+      return null;
+    }
+
+    return this._createBlocklistURL(blockEntry.blockID);
+  },
+
+  /* See nsIBlocklistService */
+  getPluginInfoURL: function(plugin) {
+    if (!this._isBlocklistLoaded())
+      this._loadBlocklist();
+
+    let r = this._getPluginBlocklistEntry(plugin, this._pluginEntries);
+    if (!r) {
+      return null;
+    }
+    let {entry: blockEntry, version: blockEntryVersion} = r;
+    if (!blockEntry.blockID) {
+      return null;
+    }
+
+    return blockEntry.infoURL;
+  },
+
+  _notifyObserversBlocklistGFX: function () {
+    // Notify `GfxInfoBase`, by passing a string serialization.
+    // This way we avoid spreading XML structure logics there.
+    const payload = this._gfxEntries.map((r) => {
+      return Object.keys(r).sort().filter((k) => !/id|last_modified/.test(k)).map((key) => {
+        let value = r[key];
+        if (Array.isArray(value)) {
+          value = value.join(",");
+        } else if (value.hasOwnProperty("minVersion")) {
+          // When XML is parsed, both minVersion and maxVersion are set.
+          value = `${value.minVersion},${value.maxVersion}`;
+        }
+        return `${key}:${value}`;
+      }).join("\t");
+    }).join("\n");
+    Services.obs.notifyObservers(null, "blocklist-data-gfxItems", payload);
+  },
+
+  _notifyObserversBlocklistUpdated: function() {
+    Services.obs.notifyObservers(this, "blocklist-updated", "");
+    Services.ppmm.broadcastAsyncMessage("Blocklist:blocklistInvalidated", {});
+  },
+
+  _blocklistUpdated: function(oldAddonEntries, oldPluginEntries) {
+    var addonList = [];
+
+    // A helper function that reverts the prefs passed to default values.
+    function resetPrefs(prefs) {
+      for (let pref of prefs)
+        gPref.clearUserPref(pref);
+    }
+    const types = ["extension", "theme", "locale", "dictionary", "service"];
+    AddonManager.getAddonsByTypes(types, addons => {
+      for (let addon of addons) {
+        let oldState = Ci.nsIBlocklistService.STATE_NOTBLOCKED;
+        if (oldAddonEntries)
+          oldState = this._getAddonBlocklistState(addon, oldAddonEntries);
+        let state = this.getAddonBlocklistState(addon);
+
+        LOG("Blocklist state for " + addon.id + " changed from " +
+            oldState + " to " + state);
+
+        // We don't want to re-warn about add-ons
+        if (state == oldState)
+          continue;
+
+        if (state === Ci.nsIBlocklistService.STATE_BLOCKED) {
+          // It's a hard block. We must reset certain preferences.
+          let prefs = this._getAddonPrefs(addon);
+          resetPrefs(prefs);
+         }
+
+        // Ensure that softDisabled is false if the add-on is not soft blocked
+        if (state != Ci.nsIBlocklistService.STATE_SOFTBLOCKED)
+          addon.softDisabled = false;
+
+        // Don't warn about add-ons becoming unblocked.
+        if (state == Ci.nsIBlocklistService.STATE_NOT_BLOCKED)
+          continue;
+
+        // If an add-on has dropped from hard to soft blocked just mark it as
+        // soft disabled and don't warn about it.
+        if (state == Ci.nsIBlocklistService.STATE_SOFTBLOCKED &&
+            oldState == Ci.nsIBlocklistService.STATE_BLOCKED) {
+          addon.softDisabled = true;
+          continue;
+        }
+
+        // If the add-on is already disabled for some reason then don't warn
+        // about it
+        if (!addon.isActive) {
+          // But mark it as softblocked if necessary. Note that we avoid setting
+          // softDisabled at the same time as userDisabled to make it clear
+          // which was the original cause of the add-on becoming disabled in a
+          // way that the user can change.
+          if (state == Ci.nsIBlocklistService.STATE_SOFTBLOCKED && !addon.userDisabled)
+            addon.softDisabled = true;
+          continue;
+        }
+
+        addonList.push({
+          name: addon.name,
+          version: addon.version,
+          icon: addon.iconURL,
+          disable: false,
+          blocked: state == Ci.nsIBlocklistService.STATE_BLOCKED,
+          item: addon,
+          url: this.getAddonBlocklistURL(addon),
+        });
+      }
+
+      AddonManagerPrivate.updateAddonAppDisabledStates();
+
+      var phs = Cc["@mozilla.org/plugin/host;1"].
+                getService(Ci.nsIPluginHost);
+      var plugins = phs.getPluginTags();
+
+      for (let plugin of plugins) {
+        let oldState = -1;
+        if (oldPluginEntries)
+          oldState = this._getPluginBlocklistState(plugin, oldPluginEntries);
+        let state = this.getPluginBlocklistState(plugin);
+        LOG("Blocklist state for " + plugin.name + " changed from " +
+            oldState + " to " + state);
+        // We don't want to re-warn about items
+        if (state == oldState)
+          continue;
+
+        if (oldState == Ci.nsIBlocklistService.STATE_BLOCKED) {
+          if (state == Ci.nsIBlocklistService.STATE_SOFTBLOCKED)
+            plugin.enabledState = Ci.nsIPluginTag.STATE_DISABLED;
+        }
+        else if (!plugin.disabled && state != Ci.nsIBlocklistService.STATE_NOT_BLOCKED) {
+          if (state != Ci.nsIBlocklistService.STATE_OUTDATED &&
+              state != Ci.nsIBlocklistService.STATE_VULNERABLE_UPDATE_AVAILABLE &&
+              state != Ci.nsIBlocklistService.STATE_VULNERABLE_NO_UPDATE) {
+            addonList.push({
+              name: plugin.name,
+              version: plugin.version,
+              icon: "chrome://mozapps/skin/plugins/pluginGeneric.png",
+              disable: false,
+              blocked: state == Ci.nsIBlocklistService.STATE_BLOCKED,
+              item: plugin,
+              url: this.getPluginBlocklistURL(plugin),
+            });
+          }
+        }
+      }
+
+      if (addonList.length == 0) {
+        this._notifyObserversBlocklistUpdated();
+        return;
+      }
+
+      if ("@mozilla.org/addons/blocklist-prompt;1" in Cc) {
+        try {
+          let blockedPrompter = Cc["@mozilla.org/addons/blocklist-prompt;1"]
+                                 .getService(Ci.nsIBlocklistPrompt);
+          blockedPrompter.prompt(addonList);
+        } catch (e) {
+          LOG(e);
+        }
+        this._notifyObserversBlocklistUpdated();
+        return;
+      }
+
+      var args = {
+        restart: false,
+        list: addonList
+      };
+      // This lets the dialog get the raw js object
+      args.wrappedJSObject = args;
+
+      /*
+        Some tests run without UI, so the async code listens to a message
+        that can be sent programatically
+      */
+      let applyBlocklistChanges = () => {
+        for (let addon of addonList) {
+          if (!addon.disable)
+            continue;
+
+          if (addon.item instanceof Ci.nsIPluginTag)
+            addon.item.enabledState = Ci.nsIPluginTag.STATE_DISABLED;
+          else {
+            // This add-on is softblocked.
+            addon.item.softDisabled = true;
+            // We must revert certain prefs.
+            let prefs = this._getAddonPrefs(addon.item);
+            resetPrefs(prefs);
+          }
+        }
+
+        if (args.restart)
+          restartApp();
+
+        this._notifyObserversBlocklistUpdated();
+        Services.obs.removeObserver(applyBlocklistChanges, "addon-blocklist-closed");
+      }
+
+      Services.obs.addObserver(applyBlocklistChanges, "addon-blocklist-closed", false);
+
+      if (getPref("getBoolPref", PREF_BLOCKLIST_SUPPRESSUI, false)) {
+        applyBlocklistChanges();
+        return;
+      }
+
+      function blocklistUnloadHandler(event) {
+        if (event.target.location == URI_BLOCKLIST_DIALOG) {
+          applyBlocklistChanges();
+          blocklistWindow.removeEventListener("unload", blocklistUnloadHandler);
+        }
+      }
+
+      let blocklistWindow = Services.ww.openWindow(null, URI_BLOCKLIST_DIALOG, "",
+                              "chrome,centerscreen,dialog,titlebar", args);
+      if (blocklistWindow)
+        blocklistWindow.addEventListener("unload", blocklistUnloadHandler, false);
+    });
+  },
+
+  classID: Components.ID("{66354bc9-7ed1-4692-ae1d-8da97d6b205e}"),
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
+                                         Ci.nsIBlocklistService,
+                                         Ci.nsITimerCallback]),
+};
+
+/**
+ * Helper for constructing a blocklist.
+ */
+function BlocklistItemData(versionRangeElement) {
+  var versionRange = this.getBlocklistVersionRange(versionRangeElement);
+  this.minVersion = versionRange.minVersion;
+  this.maxVersion = versionRange.maxVersion;
+  if (versionRangeElement && versionRangeElement.hasAttribute("severity"))
+    this.severity = versionRangeElement.getAttribute("severity");
+  else
+    this.severity = DEFAULT_SEVERITY;
+  if (versionRangeElement && versionRangeElement.hasAttribute("vulnerabilitystatus")) {
+    this.vulnerabilityStatus = versionRangeElement.getAttribute("vulnerabilitystatus");
+  } else {
+    this.vulnerabilityStatus = VULNERABILITYSTATUS_NONE;
+  }
+  this.targetApps = { };
+  var found = false;
+
+  if (versionRangeElement) {
+    for (var i = 0; i < versionRangeElement.childNodes.length; ++i) {
+      var targetAppElement = versionRangeElement.childNodes.item(i);
+      if (!(targetAppElement instanceof Ci.nsIDOMElement) ||
+          targetAppElement.localName != "targetApplication")
+        continue;
+      found = true;
+      // default to the current application if id is not provided.
+      var appID = targetAppElement.hasAttribute("id") ? targetAppElement.getAttribute("id") : gApp.ID;
+      this.targetApps[appID] = this.getBlocklistAppVersions(targetAppElement);
+    }
+  }
+  // Default to all versions of the current application when no targetApplication
+  // elements were found
+  if (!found)
+    this.targetApps[gApp.ID] = this.getBlocklistAppVersions(null);
+}
+
+BlocklistItemData.prototype = {
+  /**
+   * Tests if a version of an item is included in the version range and target
+   * application information represented by this BlocklistItemData using the
+   * provided application and toolkit versions.
+   * @param   version
+   *          The version of the item being tested.
+   * @param   appVersion
+   *          The application version to test with.
+   * @param   toolkitVersion
+   *          The toolkit version to test with.
+   * @returns True if the version range covers the item version and application
+   *          or toolkit version.
+   */
+  includesItem: function(version, appVersion, toolkitVersion) {
+    // Some platforms have no version for plugins, these don't match if there
+    // was a min/maxVersion provided
+    if (!version && (this.minVersion || this.maxVersion))
+      return false;
+
+    // Check if the item version matches
+    if (!this.matchesRange(version, this.minVersion, this.maxVersion))
+      return false;
+
+    // Check if the application version matches
+    if (this.matchesTargetRange(gApp.ID, appVersion))
+      return true;
+
+    // Check if the toolkit version matches
+    return this.matchesTargetRange(TOOLKIT_ID, toolkitVersion);
+  },
+
+  /**
+   * Checks if a version is higher than or equal to the minVersion (if provided)
+   * and lower than or equal to the maxVersion (if provided).
+   * @param   version
+   *          The version to test.
+   * @param   minVersion
+   *          The minimum version. If null it is assumed that version is always
+   *          larger.
+   * @param   maxVersion
+   *          The maximum version. If null it is assumed that version is always
+   *          smaller.
+   */
+  matchesRange: function(version, minVersion, maxVersion) {
+    if (minVersion && gVersionChecker.compare(version, minVersion) < 0)
+      return false;
+    if (maxVersion && gVersionChecker.compare(version, maxVersion) > 0)
+      return false;
+    return true;
+  },
+
+  /**
+   * Tests if there is a matching range for the given target application id and
+   * version.
+   * @param   appID
+   *          The application ID to test for, may be for an application or toolkit
+   * @param   appVersion
+   *          The version of the application to test for.
+   * @returns True if this version range covers the application version given.
+   */
+  matchesTargetRange: function(appID, appVersion) {
+    var blTargetApp = this.targetApps[appID];
+    if (!blTargetApp)
+      return false;
+
+    for (let app of blTargetApp) {
+      if (this.matchesRange(appVersion, app.minVersion, app.maxVersion))
+        return true;
+    }
+
+    return false;
+  },
+
+  /**
+   * Retrieves a version range (e.g. minVersion and maxVersion) for a
+   * blocklist item's targetApplication element.
+   * @param   targetAppElement
+   *          A targetApplication blocklist element.
+   * @returns An array of JS objects with the following properties:
+   *          "minVersion"  The minimum version in a version range (default = null).
+   *          "maxVersion"  The maximum version in a version range (default = null).
+   */
+  getBlocklistAppVersions: function(targetAppElement) {
+    var appVersions = [ ];
+
+    if (targetAppElement) {
+      for (var i = 0; i < targetAppElement.childNodes.length; ++i) {
+        var versionRangeElement = targetAppElement.childNodes.item(i);
+        if (!(versionRangeElement instanceof Ci.nsIDOMElement) ||
+            versionRangeElement.localName != "versionRange")
+          continue;
+        appVersions.push(this.getBlocklistVersionRange(versionRangeElement));
+      }
+    }
+    // return minVersion = null and maxVersion = null if no specific versionRange
+    // elements were found
+    if (appVersions.length == 0)
+      appVersions.push(this.getBlocklistVersionRange(null));
+    return appVersions;
+  },
+
+  /**
+   * Retrieves a version range (e.g. minVersion and maxVersion) for a blocklist
+   * versionRange element.
+   * @param   versionRangeElement
+   *          The versionRange blocklist element.
+   * @returns A JS object with the following properties:
+   *          "minVersion"  The minimum version in a version range (default = null).
+   *          "maxVersion"  The maximum version in a version range (default = null).
+   */
+  getBlocklistVersionRange: function(versionRangeElement) {
+    var minVersion = null;
+    var maxVersion = null;
+    if (!versionRangeElement)
+      return { minVersion: minVersion, maxVersion: maxVersion };
+
+    if (versionRangeElement.hasAttribute("minVersion"))
+      minVersion = versionRangeElement.getAttribute("minVersion");
+    if (versionRangeElement.hasAttribute("maxVersion"))
+      maxVersion = versionRangeElement.getAttribute("maxVersion");
+
+    return { minVersion: minVersion, maxVersion: maxVersion };
+  }
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([Blocklist]);