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/* -*- 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
/* eslint "valid-jsdoc": [2, {requireReturn: false}] */
import { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
AddonManager: "resource://gre/modules/AddonManager.sys.mjs",
AddonManagerPrivate: "resource://gre/modules/AddonManager.sys.mjs",
});
const CascadeFilter = Components.Constructor(
"@mozilla.org/cascade-filter;1",
"nsICascadeFilter",
"setFilterData"
);
// The whole ID should be surrounded by literal ().
// IDs may contain alphanumerics, _, -, {}, @ and a literal '.'
// They may also contain backslashes (needed to escape the {} and dot)
// We filter out backslash escape sequences (like `\w`) separately
// (see kEscapeSequences).
const kIdSubRegex =
"\\([" +
"\\\\" + // note: just a backslash, but between regex and string it needs escaping.
"\\w .{}@-]+\\)";
// prettier-ignore
// Find regular expressions of the form:
// /^((id1)|(id2)|(id3)|...|(idN))$/
// The outer set of parens enclosing the entire list of IDs is optional.
const kIsMultipleIds = new RegExp(
// Start with literal sequence /^(
// (the `(` is optional)
"^/\\^\\(?" +
// Then at least one ID in parens ().
kIdSubRegex +
// Followed by any number of IDs in () separated by pipes.
// Note: using a non-capturing group because we don't care about the value.
"(?:\\|" + kIdSubRegex + ")*" +
// Finally, we need to end with literal sequence )$/
// (the leading `)` is optional like at the start)
"\\)?\\$/$"
);
// Check for a backslash followed by anything other than a literal . or curlies
const kEscapeSequences = /\\[^.{}]/;
// Used to remove the following 3 things:
// leading literal /^(
// plus an optional (
// any backslash
// trailing literal )$/
// plus an optional ) before the )$/
const kRegExpRemovalRegExp = /^\/\^\(\(?|\\|\)\)?\$\/$/g;
// In order to block add-ons, their type should be part of this list. There
// may be additional requirements such as requiring the add-on to be signed.
// See the uses of kXPIAddonTypes before introducing new addon types or
// providers that differ from the existing types.
ChromeUtils.defineLazyGetter(lazy, "kXPIAddonTypes", () => {
// In practice, this result is equivalent to ALL_XPI_TYPES in
// XPIProvider.sys.mjs.
// "plugin" (from GMPProvider.sys.mjs) is intentionally omitted, as we decided to
return lazy.AddonManagerPrivate.getAddonTypesByProvider("XPIProvider");
});
// For a given input string matcher, produce either a string to compare with,
// a regular expression, or a set of strings to compare with.
function processMatcher(str) {
if (!str.startsWith("/")) {
return str;
}
// Process regexes matching multiple IDs into a set.
if (kIsMultipleIds.test(str) && !kEscapeSequences.test(str)) {
// Remove the regexp gunk at the start and end of the string, as well
// as all backslashes, and split by )|( to leave the list of IDs.
return new Set(str.replace(kRegExpRemovalRegExp, "").split(")|("));
}
let lastSlash = str.lastIndexOf("/");
let pattern = str.slice(1, lastSlash);
let flags = str.slice(lastSlash + 1);
return new RegExp(pattern, flags);
}
// Returns true if the addonProps object passes the constraints set by matches.
// (For every non-null property in matches, the same key must exist in
// addonProps and its value must match)
function doesAddonEntryMatch(matches, addonProps) {
for (let [key, value] of Object.entries(matches)) {
if (value === null || value === undefined) {
continue;
}
if (addonProps[key]) {
// If this property matches (member of the set, matches regex, or
// an exact string match), continue to look at the other properties of
// the `matches` object.
// If not, return false immediately.
if (value.has && value.has(addonProps[key])) {
continue;
}
if (value.test && value.test(addonProps[key])) {
continue;
}
if (typeof value == "string" && value === addonProps[key]) {
continue;
}
}
// If we get here, the property doesn't match, so this entry doesn't match.
return false;
}
// If we get here, all the properties must have matched.
return true;
}
const TOOLKIT_ID = "toolkit@mozilla.org";
const PREF_BLOCKLIST_ITEM_URL = "extensions.blocklist.itemURL";
const PREF_BLOCKLIST_ADDONITEM_URL = "extensions.blocklist.addonItemURL";
const PREF_BLOCKLIST_ENABLED = "extensions.blocklist.enabled";
const PREF_BLOCKLIST_SOFTBLOCK_ENABLED =
"extensions.blocklist.softblock.enabled";
const PREF_BLOCKLIST_LEVEL = "extensions.blocklist.level";
const PREF_BLOCKLIST_USE_MLBF = "extensions.blocklist.useMLBF";
const PREF_EM_LOGGING_ENABLED = "extensions.logging.enabled";
const DEFAULT_SEVERITY = 3;
const DEFAULT_LEVEL = 2;
const MAX_BLOCK_LEVEL = 3;
const BLOCKLIST_BUCKET = "blocklists";
const BlocklistTelemetry = {
/**
* Record the RemoteSettings Blocklist lastModified server time into the
* "blocklist.lastModified_rs keyed scalar (or "Missing Date" when unable
* to retrieve a valid timestamp).
*
* @param {string} blocklistType
* The blocklist type that has been updated ("addons" or "addons_mlbf");
* the "gfx" blocklist is not covered by this telemetry).
* @param {RemoteSettingsClient} remoteSettingsClient
* The RemoteSettings client to retrieve the lastModified timestamp from.
*/
async recordRSBlocklistLastModified(blocklistType, remoteSettingsClient) {
// In some tests overrides ensureInitialized and remoteSettingsClient
// can be undefined, and in that case we don't want to record any
// telemetry scalar.
if (!remoteSettingsClient) {
return;
}
let lastModified = await remoteSettingsClient.getLastModified();
if (blocklistType === "addons_mlbf") {
BlocklistTelemetry.recordGleanDateTime(
Glean.blocklist.lastModifiedRsAddonsMblf,
lastModified
);
}
},
/**
* Records a glean datetime if time is > than 0, otherwise 0 is submitted.
*
* @param {nsIGleanDatetime} gleanTelemetry
* A glean telemetry datetime object.
* @param {number} time
* A timestamp to record.
*/
recordGleanDateTime(gleanTelemetry, time) {
if (time > 0) {
// Glean date times are provided in nanoseconds, `getTime()` yields
// milliseconds (after the Unix epoch).
gleanTelemetry.set(time * 1000);
} else {
gleanTelemetry.set(0);
}
},
/**
* Record whether an add-on is blocked and the parameters that guided the
* decision to block or unblock the add-on.
*
* @param {AddonWrapper|object} addon
* The blocked or unblocked add-on. Not necessarily installed.
* Could be an object with the id, version and blocklistState
* properties when the AddonWrapper is not available (e.g. during
* update checks).
* @param {string} reason
* The reason for recording the event,
* "addon_install", "addon_update", "addon_update_check",
* "addon_db_modified", "blocklist_update".
*/
recordAddonBlockChangeTelemetry(addon, reason) {
// Reduce the timer resolution for anonymity.
let hoursSinceInstall = -1;
if (reason === "blocklist_update" || reason === "addon_db_modified") {
hoursSinceInstall = Math.round(
(Date.now() - addon.installDate.getTime()) / 3600000
);
}
Glean.blocklist.addonBlockChange.record({
value: addon.id,
object: reason,
blocklist_state: addon.blocklistState,
addon_version: addon.version,
signed_date: addon.signedDate?.getTime() || 0,
hours_since: hoursSinceInstall,
...ExtensionBlocklistMLBF.getBlocklistMetadataForTelemetry(),
});
},
};
const Utils = {
/**
* Checks whether this entry is valid for the current OS and ABI.
* If the entry has an "os" property then the current OS must appear in
* its comma separated list for it to be valid. Similarly for the
* xpcomabi property.
*
* @param {Object} item
* The blocklist item.
* @returns {bool}
* Whether the entry matches the current OS.
*/
matchesOSABI(item) {
if (item.os) {
let os = item.os.split(",");
if (!os.includes(lazy.gAppOS)) {
return false;
}
}
if (item.xpcomabi) {
let xpcomabi = item.xpcomabi.split(",");
if (!xpcomabi.includes(lazy.gApp.XPCOMABI)) {
return false;
}
}
return true;
},
/**
* 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 {string} version
* The version to test.
* @param {string?} minVersion
* The minimum version. If null it is assumed that version is always
* larger.
* @param {string?} maxVersion
* The maximum version. If null it is assumed that version is always
* smaller.
* @returns {boolean}
* Whether the item matches the range.
*/
versionInRange(version, minVersion, maxVersion) {
if (minVersion && Services.vc.compare(version, minVersion) < 0) {
return false;
}
if (maxVersion && Services.vc.compare(version, maxVersion) > 0) {
return false;
}
return true;
},
/**
* Tests if this versionRange matches the item specified, and has a matching
* targetApplication id and version.
* @param {Object} versionRange
* The versionRange to check against
* @param {string} itemVersion
* The version of the actual addon/plugin to test for.
* @param {string} appVersion
* The version of the application to test for.
* @param {string} toolkitVersion
* The version of toolkit to check for.
* @returns {boolean}
* True if this version range covers the item and app/toolkit version given.
*/
versionsMatch(versionRange, itemVersion, appVersion, toolkitVersion) {
// Some platforms have no version for plugins, these don't match if there
// was a min/maxVersion provided
if (!itemVersion && (versionRange.minVersion || versionRange.maxVersion)) {
return false;
}
// Check if the item version matches
if (
!this.versionInRange(
itemVersion,
versionRange.minVersion,
versionRange.maxVersion
)
) {
return false;
}
// Check if the application or toolkit version matches
for (let tA of versionRange.targetApplication) {
if (
tA.guid == lazy.gAppID &&
this.versionInRange(appVersion, tA.minVersion, tA.maxVersion)
) {
return true;
}
if (
tA.guid == TOOLKIT_ID &&
this.versionInRange(toolkitVersion, tA.minVersion, tA.maxVersion)
) {
return true;
}
}
return false;
},
/**
* Given a blocklist JS object entry, ensure it has a versionRange property, where
* each versionRange property has a valid severity property
* and at least 1 valid targetApplication.
* If it didn't have a valid targetApplication array before and/or it was empty,
* fill it with an entry with null min/maxVersion properties, which will match
* every version.
*
* If there *are* targetApplications, if any of them don't have a guid property,
* assign them the current app's guid.
*
* @param {Object} entry
* blocklist entry object.
*/
ensureVersionRangeIsSane(entry) {
if (!entry.versionRange.length) {
entry.versionRange.push({});
}
for (let vr of entry.versionRange) {
if (!vr.hasOwnProperty("severity")) {
vr.severity = DEFAULT_SEVERITY;
}
if (!Array.isArray(vr.targetApplication)) {
vr.targetApplication = [];
}
if (!vr.targetApplication.length) {
vr.targetApplication.push({ minVersion: null, maxVersion: null });
}
vr.targetApplication.forEach(tA => {
if (!tA.guid) {
tA.guid = lazy.gAppID;
}
});
}
},
/**
* Create a blocklist URL for the given blockID
* @param {String} id the blockID to use
* @returns {String} the blocklist URL.
*/
_createBlocklistURL(id) {
let url = Services.urlFormatter.formatURLPref(PREF_BLOCKLIST_ITEM_URL);
return url.replace(/%blockID%/g, id);
},
};
/**
* This custom filter function is used to limit the entries returned
* by `RemoteSettings("...").get()` depending on the target app information
* defined on entries.
*
* Note that this is async because `jexlFilterFunc` is async.
*
* @param {Object} entry a Remote Settings record
* @param {Object} environment the JEXL environment object.
* @returns {Object} The entry if it matches, `null` otherwise.
*/
async function targetAppFilter(entry, environment) {
// If the entry has a JEXL filter expression, it should prevail.
// The legacy target app mechanism will be kept in place for old entries.
const { filter_expression } = entry;
if (filter_expression) {
return lazy.jexlFilterFunc(entry, environment);
}
// Keep entries without target information.
if (!("versionRange" in entry)) {
return entry;
}
const { versionRange } = entry;
// Everywhere in this method, we avoid checking the minVersion, because
// we want to retain items whose minVersion is higher than the current
// app version, so that we have the items around for app updates.
// Gfx blocklist has a specific versionRange object, which is not a list.
if (!Array.isArray(versionRange)) {
const { maxVersion = "*" } = versionRange;
const matchesRange =
Services.vc.compare(lazy.gApp.version, maxVersion) <= 0;
return matchesRange ? entry : null;
}
// Iterate the targeted applications, at least one of them must match.
// If no target application, keep the entry.
if (!versionRange.length) {
return entry;
}
for (const vr of versionRange) {
const { targetApplication = [] } = vr;
if (!targetApplication.length) {
return entry;
}
for (const ta of targetApplication) {
const { guid } = ta;
if (!guid) {
return entry;
}
const { maxVersion = "*" } = ta;
if (
guid == lazy.gAppID &&
Services.vc.compare(lazy.gApp.version, maxVersion) <= 0
) {
return entry;
}
if (
guid == "toolkit@mozilla.org" &&
Services.vc.compare(Services.appinfo.platformVersion, maxVersion) <= 0
) {
return entry;
}
}
}
// Skip this entry.
return null;
}
/**
* The Graphics blocklist implementation. The JSON objects for graphics blocks look
* something like:
*
* {
* "blockID": "g35",
* "os": "WINNT 6.1",
* "vendor": "0xabcd",
* "devices": [
* "0x2783",
* "0x1234",
* ],
* "feature": " DIRECT2D ",
* "featureStatus": " BLOCKED_DRIVER_VERSION ",
* "driverVersion": " 8.52.322.2202 ",
* "driverVersionComparator": " LESS_THAN ",
* "versionRange": {"minVersion": "5.0", "maxVersion: "25.0"},
* }
*
* The RemoteSetttings client takes care of filtering out versions that don't apply.
* The code here stores entries in memory and sends them to the gfx component in
* serialized text form, using ',', '\t' and '\n' as separators.
*/
const GfxBlocklistRS = {
_ensureInitialized() {
if (this._initialized || !gBlocklistEnabled) {
return;
}
this._initialized = true;
this._client = lazy.RemoteSettings("gfx", {
bucketName: BLOCKLIST_BUCKET,
filterFunc: targetAppFilter,
});
this.checkForEntries = this.checkForEntries.bind(this);
this._client.on("sync", this.checkForEntries);
},
shutdown() {
if (this._client) {
this._client.off("sync", this.checkForEntries);
}
},
sync() {
this._ensureInitialized();
return this._client.sync();
},
async checkForEntries() {
this._ensureInitialized();
if (!gBlocklistEnabled) {
return []; // return value expected by tests.
}
let entries = await this._client.get().catch(ex => Cu.reportError(ex));
// Handle error silently. This can happen if our request to fetch data is aborted,
// e.g. by application shutdown.
if (!entries) {
return [];
}
// Trim helper (spaces, tabs, no-break spaces..)
const trim = s =>
(s || "").replace(/(^[\s\uFEFF\xA0]+)|([\s\uFEFF\xA0]+$)/g, "");
entries = entries.map(entry => {
let props = [
"blockID",
"driverVersion",
"driverVersionMax",
"driverVersionComparator",
"feature",
"featureStatus",
"os",
"vendor",
"devices",
];
let rv = {};
for (let p of props) {
let val = entry[p];
// Ignore falsy values or empty arrays.
if (!val || (Array.isArray(val) && !val.length)) {
continue;
}
if (typeof val == "string") {
val = trim(val);
} else if (p == "devices") {
let invalidDevices = [];
let validDevices = [];
// We serialize the array of devices as a comma-separated string, so
// we need to ensure that none of the entries contain commas, also in
// the future.
val.forEach(v =>
v.includes(",") ? invalidDevices.push(v) : validDevices.push(v)
);
for (let dev of invalidDevices) {
const e = new Error(
`Block ${entry.blockID} contains unsupported device: ${dev}`
);
Cu.reportError(e);
}
if (!validDevices) {
continue;
}
val = validDevices;
}
rv[p] = val;
}
if (entry.versionRange) {
rv.versionRange = {
minVersion: trim(entry.versionRange.minVersion) || "0",
maxVersion: trim(entry.versionRange.maxVersion) || "*",
};
}
return rv;
});
if (entries.length) {
let sortedProps = [
"blockID",
"devices",
"driverVersion",
"driverVersionComparator",
"driverVersionMax",
"feature",
"featureStatus",
"hardware",
"manufacturer",
"model",
"os",
"osversion",
"product",
"vendor",
"versionRange",
];
// Notify `GfxInfoBase`, by passing a string serialization.
let payload = [];
for (let gfxEntry of entries) {
let entryLines = [];
for (let key of sortedProps) {
if (gfxEntry[key]) {
let value = gfxEntry[key];
if (Array.isArray(value)) {
value = value.join(",");
} else if (value.maxVersion) {
// Both minVersion and maxVersion are always set on each entry.
value = value.minVersion + "," + value.maxVersion;
}
entryLines.push(key + ":" + value);
}
}
payload.push(entryLines.join("\t"));
}
Services.obs.notifyObservers(
null,
"blocklist-data-gfxItems",
payload.join("\n")
);
}
// The return value is only used by tests.
return entries;
},
};
/**
* The extensions blocklist implementation. The JSON objects for extension
* blocks look something like:
*
* {
* "guid": "someguid@addons.mozilla.org",
* "prefs": ["i.am.a.pref.that.needs.resetting"],
* "schema": 1480349193877,
* "blockID": "i12345",
* "details": {
* "who": "All Firefox users who have this add-on installed. If you wish to continue using this add-on, you can enable it in the Add-ons Manager.",
* "why": "This add-on is in violation of the <a href=\"https://developer.mozilla.org/en-US/Add-ons/Add-on_guidelines\">Add-on Guidelines</a>, using multiple add-on IDs and potentially doing other unwanted activities.",
* "name": "Some pretty name",
* "created": "2019-05-06T19:52:20Z"
* },
* "enabled": true,
* "versionRange": [
* {
* "severity": 1,
* "maxVersion": "*",
* "minVersion": "0",
* "targetApplication": []
* }
* ],
* "id": "<unique guid>",
* "last_modified": 1480349215672,
* }
*
* ExtensionBlocklistMLBF supersedes this implementation.
*/
const ExtensionBlocklistRS = {
async _ensureEntries() {
this.ensureInitialized();
if (!this._entries && gBlocklistEnabled) {
await this._updateEntries();
}
},
async _updateEntries() {
if (!gBlocklistEnabled) {
this._entries = [];
return;
}
this._entries = await this._client.get().catch(ex => Cu.reportError(ex));
// Handle error silently. This can happen if our request to fetch data is aborted,
// e.g. by application shutdown.
if (!this._entries) {
this._entries = [];
return;
}
this._entries.forEach(entry => {
entry.matches = {};
if (entry.guid) {
entry.matches.id = processMatcher(entry.guid);
}
for (let key of EXTENSION_BLOCK_FILTERS) {
if (key == "id" || !entry[key]) {
continue;
}
entry.matches[key] = processMatcher(entry[key]);
}
Utils.ensureVersionRangeIsSane(entry);
});
BlocklistTelemetry.recordRSBlocklistLastModified("addons", this._client);
},
async _filterItem(entry, environment) {
if (!(await targetAppFilter(entry, environment))) {
return null;
}
if (!Utils.matchesOSABI(entry)) {
return null;
}
// Need something to filter on - at least a guid or name (either could be a regex):
if (!entry.guid && !entry.name) {
let blockID = entry.blockID || entry.id;
Cu.reportError(new Error(`Nothing to filter add-on item ${blockID} on`));
return null;
}
return entry;
},
sync() {
this.ensureInitialized();
return this._client.sync();
},
ensureInitialized() {
if (!gBlocklistEnabled || this._initialized) {
return;
}
this._initialized = true;
this._client = lazy.RemoteSettings("addons", {
bucketName: BLOCKLIST_BUCKET,
filterFunc: this._filterItem,
});
this._onUpdate = this._onUpdate.bind(this);
this._client.on("sync", this._onUpdate);
},
shutdown() {
if (this._client) {
this._client.off("sync", this._onUpdate);
this._didShutdown = true;
}
},
// Called when the blocklist implementation is changed via a pref.
undoShutdown() {
if (this._didShutdown) {
this._client.on("sync", this._onUpdate);
this._didShutdown = false;
}
},
async _onUpdate() {
let oldEntries = this._entries || [];
await this.ensureInitialized();
await this._updateEntries();
let addons = await lazy.AddonManager.getAddonsByTypes(lazy.kXPIAddonTypes);
for (let addon of addons) {
let oldState = addon.blocklistState;
if (addon.updateBlocklistState) {
await addon.updateBlocklistState(false);
} else if (oldEntries) {
let oldEntry = this._getEntry(addon, oldEntries);
oldState = oldEntry
? oldEntry.state
: Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
} else {
oldState = Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
}
let state = addon.blocklistState;
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;
}
// Ensure that softDisabled is false if the add-on is not soft-blocked
if (state != Ci.nsIBlocklistService.STATE_SOFTBLOCKED) {
await addon.setSoftDisabled(false);
}
// If an add-on has dropped from hard-blocked to soft-blocked just mark it as
// softDisabled and don't warn about it.
if (
state == Ci.nsIBlocklistService.STATE_SOFTBLOCKED &&
oldState == Ci.nsIBlocklistService.STATE_BLOCKED
) {
await addon.setSoftDisabled(true);
}
if (
state == Ci.nsIBlocklistService.STATE_BLOCKED ||
state == Ci.nsIBlocklistService.STATE_SOFTBLOCKED
) {
// Mark it as soft-blocked 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
) {
await addon.setSoftDisabled(true);
}
// It's a block. We must reset certain preferences.
let entry = this._getEntry(addon, this._entries);
if (entry.prefs && entry.prefs.length) {
for (let pref of entry.prefs) {
Services.prefs.clearUserPref(pref);
}
}
}
}
lazy.AddonManagerPrivate.updateAddonAppDisabledStates();
},
async getState(addon, appVersion, toolkitVersion) {
let entry = await this.getEntry(addon, appVersion, toolkitVersion);
return entry ? entry.state : Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
},
async getEntry(addon, appVersion, toolkitVersion) {
await this._ensureEntries();
return this._getEntry(addon, this._entries, appVersion, toolkitVersion);
},
_getEntry(addon, addonEntries, appVersion, toolkitVersion) {
if (!gBlocklistEnabled || !addon) {
return null;
}
// Not all applications implement nsIXULAppInfo (e.g. xpcshell doesn't).
if (!appVersion && !lazy.gApp.version) {
return null;
}
if (!appVersion) {
appVersion = lazy.gApp.version;
}
if (!toolkitVersion) {
toolkitVersion = lazy.gApp.platformVersion;
}
let addonProps = {};
for (let key of EXTENSION_BLOCK_FILTERS) {
addonProps[key] = addon[key];
}
if (addonProps.creator) {
addonProps.creator = addonProps.creator.name;
}
for (let entry of addonEntries) {
// First check if it matches our properties. If not, just skip to the next item.
if (!doesAddonEntryMatch(entry.matches, addonProps)) {
continue;
}
// If those match, check the app or toolkit version works:
for (let versionRange of entry.versionRange) {
if (
Utils.versionsMatch(
versionRange,
addon.version,
appVersion,
toolkitVersion
)
) {
let blockID = entry.blockID || entry.id;
return {
state:
versionRange.severity >= gBlocklistLevel
? Ci.nsIBlocklistService.STATE_BLOCKED
: Ci.nsIBlocklistService.STATE_SOFTBLOCKED,
url: Utils._createBlocklistURL(blockID),
prefs: entry.prefs || [],
};
}
}
}
return null;
},
};
/**
* The extensions blocklist implementation, the third version.
*
* The current blocklist is represented by a multi-level bloom filter (MLBF)
* (aka "Cascade Bloom Filter") that works like a set, i.e. supports a has()
* operation, except it is probabilistic. The MLBF is 100% accurate for known
* entries and unreliable for unknown entries. When the backend generates the
* MLBF, all known add-ons are recorded, including their block state. Unknown
* add-ons are identified by their signature date being newer than the MLBF's
* generation time, and they are considered to not be blocked.
*
* Legacy blocklists used to distinguish between "soft-block" and "hard-block",
* but the current blocklist only supports one type of block ("hard-block").
* After checking the blocklist states, any previous "soft-blocked" addons will
* either be (hard) blocked or unblocked based on the blocklist.
*
* The MLBF is attached to a RemoteSettings record, as follows:
*
* {
* "generation_time": 1585692000000,
* "attachment": { ... RemoteSettings attachment ... }
* "attachment_type": "bloomfilter-base",
* }
*
* The collection can also contain stashes:
*
* {
* "stash_time": 1585692000001,
* "stash": {
* "blocked": [ "addonid:1.0", ... ],
* "unblocked": [ "addonid:1.0", ... ]
* }
*
* Stashes can be used to update the blocklist without forcing the whole MLBF
* to be downloaded again. These stashes are applied on top of the base MLBF.
*/
const ExtensionBlocklistMLBF = {
// ID to identify cached or bundled attachment. Supersedes the id from
// the record to ensure that there is only one cached entry, and enables
// lookup of cached attachments even without record.
RS_ATTACHMENT_ID: "addons-mlbf.bin",
RS_ATTACHMENT_TYPE: "bloomfilter-base",
RS_SOFTBLOCKS_ATTACHMENT_ID: "softblocks-addons-mlbf.bin",
RS_SOFTBLOCKS_ATTACHMENT_TYPE: "softblocks-bloomfilter-base",
async _getMLBFData(record, attachmentId, mlbfData) {
// |record| may be unset. In that case, the MLBF dump is used instead
// (provided that the client has been built with it included).
let hash = record?.attachment.hash;
if (mlbfData && hash && mlbfData.cascadeHash === hash) {
// MLBF not changed, save the efforts of downloading the data again.
// Although the MLBF has not changed, the time in the record has. This
// means that the MLBF is known to provide accurate results for add-ons
// that were signed after the previously known date (but before the newly
// given date). To ensure that add-ons in this time range are also blocked
// as expected, update the cached generationTime.
if (record.generation_time > mlbfData.generationTime) {
mlbfData.generationTime = record.generation_time;
}
return mlbfData;
}
const {
buffer,
record: actualRecord,
_source: rsAttachmentSource,
} = await this._client.attachments.download(record, {
attachmentId,
fallbackToCache: true,
fallbackToDump: true,
});
return {
cascadeHash: actualRecord.attachment.hash,
cascadeFilter: new CascadeFilter(new Uint8Array(buffer)),
// Note: generation_time is semantically distinct from last_modified.
// generation_time is compared with the signing date of the add-on, so it
// should be in sync with the signing service's clock.
// In contrast, last_modified does not have such strong requirements.
generationTime: actualRecord.generation_time,
// Used for telemetry.
rsAttachmentSource,
};
},
async _fetchMLBF(recordHardBlocks, recordSoftBlocks) {
const [mlbfRes, mlbfSoftBlocksRes] = await Promise.allSettled([
this._getMLBFData(
recordHardBlocks,
this.RS_ATTACHMENT_ID,
this._mlbfData
),
gBlocklistSoftBlockEnabled
? this._getMLBFData(
recordSoftBlocks,
this.RS_SOFTBLOCKS_ATTACHMENT_ID,
this._mlbfDataSoftBlocks
)
: undefined,
]);
if (mlbfRes.reason) {
throw mlbfRes.reason;
}
if (mlbfSoftBlocksRes.reason) {
// Allow the soft-blocks mlbf attachment to fail to be retrieved.
Cu.reportError(mlbfSoftBlocksRes.reason);
}
return {
mlbf: mlbfRes.value,
mlbfSoftBlocks: mlbfSoftBlocksRes.value,
};
},
async _updateMLBF(forceUpdate = false) {
// The update process consists of fetching the collection, followed by
// potentially multiple network requests. As long as the collection has not
// been changed, repeated update requests can be coalesced. But when the
// collection has been updated, all pending update requests should await the
// new update request instead of the previous one.
if (!forceUpdate && this._updatePromise) {
return this._updatePromise;
}
const isUpdateReplaced = () => this._updatePromise != updatePromise;
const updatePromise = (async () => {
if (!gBlocklistEnabled) {
this._mlbfData = null;
this._mlbfDataSoftBlocks = null;
this._stashes = null;
return;
}
if (!gBlocklistSoftBlockEnabled) {
this._mlbfDataSoftBlocks = null;
}
let records = await this._client.get();
if (isUpdateReplaced()) {
return;
}
let mlbfRecords = records
.filter(r => r.attachment)
// Newest attachments first.
.sort((a, b) => b.generation_time - a.generation_time);
const mlbfRecord = mlbfRecords.find(
r => r.attachment_type == this.RS_ATTACHMENT_TYPE
);
const mlbfRecordSoftBlocks = gBlocklistSoftBlockEnabled
? mlbfRecords.find(
r => r.attachment_type == this.RS_SOFTBLOCKS_ATTACHMENT_TYPE
)
: undefined;
this._stashes = records
.filter(({ stash }) => {
return (
// Exclude non-stashes, e.g. MLBF attachments.
stash &&
// Sanity check for type.
Array.isArray(stash.blocked) &&
Array.isArray(stash.unblocked) &&
// NOTE: `softblocked` property is expected to not be
// available for old existing records.
(!stash.softblocked || Array.isArray(stash.softblocked))
);
})
// Sort by stash time - newest first.
.sort((a, b) => b.stash_time - a.stash_time)
.map(({ stash, stash_time }) => ({
blocked: new Set(stash.blocked),
unblocked: new Set(stash.unblocked),
softblocked: new Set(
(gBlocklistSoftBlockEnabled && stash.softblocked) || []
),
stash_time,
}));
let { mlbf, mlbfSoftBlocks } = await this._fetchMLBF(
mlbfRecord,
mlbfRecordSoftBlocks
);
// When a MLBF dump is packaged with the browser, mlbf will always be
// non-null at this point.
if (isUpdateReplaced()) {
return;
}
this._mlbfData = mlbf;
this._mlbfDataSoftBlocks = mlbfSoftBlocks;
})()
.catch(e => {
Cu.reportError(e);
})
.then(() => {
if (!isUpdateReplaced()) {
this._updatePromise = null;
this._recordPostUpdateTelemetry();
}
return this._updatePromise;
});
this._updatePromise = updatePromise;
return updatePromise;
},
// Update the telemetry of the blocklist. This is always called, even if
// the update request failed (e.g. due to network errors or data corruption).
_recordPostUpdateTelemetry() {
BlocklistTelemetry.recordRSBlocklistLastModified(
"addons_mlbf",
this._client
);
Glean.blocklist.mlbfSource.set(
this._mlbfData?.rsAttachmentSource || "unknown"
);
Glean.blocklist.mlbfSoftblocksSource.set(
this._mlbfDataSoftBlocks?.rsAttachmentSource || "unknown"
);
BlocklistTelemetry.recordGleanDateTime(
Glean.blocklist.mlbfGenerationTime,
this._mlbfData?.generationTime
);
BlocklistTelemetry.recordGleanDateTime(
Glean.blocklist.mlbfSoftblocksGenerationTime,
this._mlbfDataSoftBlocks?.generationTime
);
// stashes has conveniently already been sorted by stash_time, newest first.
let stashes = this._stashes || [];
BlocklistTelemetry.recordGleanDateTime(
Glean.blocklist.mlbfStashTimeOldest,
stashes[stashes.length - 1]?.stash_time
);
BlocklistTelemetry.recordGleanDateTime(
Glean.blocklist.mlbfStashTimeNewest,
stashes[0]?.stash_time
);
},
// Used by BlocklistTelemetry.recordAddonBlockChangeTelemetry.
getBlocklistMetadataForTelemetry() {
// Blocklist telemetry can only be reported when a blocklist decision
// has been made. That implies that the blocklist has been loaded, so
// ExtensionBlocklistMLBF should have been initialized.
// (except when the blocklist is disabled, or blocklist v2 is used)
const generationTime = this._mlbfData?.generationTime ?? 0;
const softblocksGenerationTime =
this._mlbfDataSoftBlocks?.generationTime ?? 0;
// Keys to include in the blocklist.addonBlockChange telemetry event.
return {
mlbf_last_time:
// stashes are sorted, newest first. Stashes are newer than the MLBF.
`${this._stashes?.[0]?.stash_time ?? generationTime}`,
mlbf_generation: `${generationTime}`,
mlbf_source: this._mlbfData?.rsAttachmentSource ?? "unknown",
mlbf_softblocks_generation: `${softblocksGenerationTime}`,
mlbf_softblocks_source:
this._mlbfDataSoftBlocks?.rsAttachmentSource ?? "unknown",
};
},
ensureInitialized() {
if (!gBlocklistEnabled || this._initialized) {
return;
}
this._initialized = true;
this._client = lazy.RemoteSettings("addons-bloomfilters", {
bucketName: BLOCKLIST_BUCKET,
// Prevent the attachment for being pruned, since its ID does
// not match any record.
keepAttachmentsIds: [
this.RS_ATTACHMENT_ID,
this.RS_SOFTBLOCKS_ATTACHMENT_ID,
],
});
this._onUpdate = this._onUpdate.bind(this);
this._client.on("sync", this._onUpdate);
},
shutdown() {
if (this._client) {
this._client.off("sync", this._onUpdate);
this._didShutdown = true;
}
},
// Called when the blocklist implementation is changed via a pref.
undoShutdown() {
if (this._didShutdown) {
this._client.on("sync", this._onUpdate);
this._didShutdown = false;
}
},
async _onUpdate() {
this.ensureInitialized();
await this._updateMLBF(true);
let addons = await lazy.AddonManager.getAddonsByTypes(lazy.kXPIAddonTypes);
for (let addon of addons) {
let oldState = addon.blocklistState;
await addon.updateBlocklistState(true /* applySoftBlock */);
let state = addon.blocklistState;
LOG(
"Blocklist state for " +
addon.id +
" changed from " +
oldState +
" to " +
state
);
if (state == oldState) {
continue;
}
BlocklistTelemetry.recordAddonBlockChangeTelemetry(
addon,
"blocklist_update"
);
}
lazy.AddonManagerPrivate.updateAddonAppDisabledStates();
},
async getState(addon) {
let state = await this.getEntry(addon);
return state ? state.state : Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
},
async getEntry(addon) {
if (!this._stashes) {
this.ensureInitialized();
await this._updateMLBF(false);
} else if (this._updatePromise) {
// _stashes has been initialized, but the initialization of _mlbfData is
// still pending.
await this._updatePromise;
}
let blockKey = addon.id + ":" + addon.version;
let blockTimestamp = -Infinity;
let blockState;
let blockSource;
// _stashes will be unset if !gBlocklistEnabled.
if (this._stashes) {
// Stashes are ordered by newest first.
for (let stash of this._stashes) {
// hard-blocked and soft-blocked/not-blocked do not have overlapping entries.
if (stash.blocked.has(blockKey)) {
blockState = Ci.nsIBlocklistService.STATE_BLOCKED;
blockTimestamp = stash.stash_time;
blockSource = "stash";
break;
}
if (stash.softblocked.has(blockKey)) {
blockState = Ci.nsIBlocklistService.STATE_SOFTBLOCKED;
blockTimestamp = stash.stash_time;
blockSource = "stash";
break;
}
if (stash.unblocked.has(blockKey)) {
blockState = Ci.nsIBlocklistService.STATE_NOT_BLOCKED;
blockTimestamp = stash.stash_time;
blockSource = "stash";
break;
}
}
}
// Determine if the hard-blocks MLBF data has a more recent
// STATE_BLOCKED blocklist state.
if (
this._mlbfData?.generationTime > blockTimestamp &&
this._isAddonInMLBFData(addon, this._mlbfData)
) {
blockState = Ci.nsIBlocklistService.STATE_BLOCKED;
blockSource = this.RS_ATTACHMENT_TYPE;
blockTimestamp = this._mlbfData.generationTime;
}
// Determine if the soft-blocks MLBF data has a more recent
// STATE_SOFTBLOCKED blocklist state.
if (
this._mlbfDataSoftBlocks?.generationTime > blockTimestamp &&
this._isAddonInMLBFData(addon, this._mlbfDataSoftBlocks)
) {
blockState = Ci.nsIBlocklistService.STATE_SOFTBLOCKED;
blockSource = this.RS_SOFTBLOCKS_ATTACHMENT_TYPE;
blockTimestamp = this._mlbfDataSoftBlocks.generationTime;
}
if (blockSource) {
LOG(
`ExtensionBlocklistMLBF.getEntry: block entry for ${blockKey} - ` +
`state ${blockState}, source ${blockSource}, timestamp ${blockTimestamp}`
);
}
if (blockState === Ci.nsIBlocklistService.STATE_BLOCKED) {
return this._createBlockEntry({ addon });
}
if (blockState === Ci.nsIBlocklistService.STATE_SOFTBLOCKED) {
return this._createBlockEntry({ addon, softBlock: true });
}
return null;
},
_isAddonInMLBFData(addon, mlbfData) {
// signedDate is a Date if the add-on is signed, null if not signed,
// undefined if it's an addon update descriptor instead of an addon wrapper.
let { signedDate } = addon;
if (!signedDate) {
// The MLBF does not apply to unsigned add-ons.
return false;
}
if (!mlbfData) {
// This could happen in theory in any of the following cases:
// - the blocklist is disabled.
// - The RemoteSettings backend served a malformed MLBF.
// - The RemoteSettings backend is unreachable, and this client was built
// without including a dump of the MLBF.
//
// ... in other words, this is unlikely to happen for hard-blocks in practice.
//
// For soft-blocks MLBF data may be missing if the volume of the soft-blocks
// is being low enough to fit into the stashes.
return false;
}
let blockKey = addon.id + ":" + addon.version;
let { cascadeFilter, generationTime } = mlbfData;
if (!cascadeFilter.has(blockKey)) {
// Add-on was not blocked when this MLBF was generated,
// or add-on unknown at generation time of this MLBF.
return false;
}
// Add-on blocked, or unknown add-on inadvertently labeled as blocked.
let { signedState } = addon;
if (
signedState !== lazy.AddonManager.SIGNEDSTATE_PRELIMINARY &&
signedState !== lazy.AddonManager.SIGNEDSTATE_SIGNED
) {
// The block decision can only be relied upon for known add-ons, i.e.
// signed via AMO. Anything else is unknown and ignored:
//
// - SIGNEDSTATE_SYSTEM and SIGNEDSTATE_PRIVILEGED are signed
// independently of AMO.
//
// - SIGNEDSTATE_NOT_REQUIRED already has an early return above due to
// signedDate being unset for these kinds of add-ons.
//
// - SIGNEDSTATE_BROKEN, SIGNEDSTATE_UNKNOWN and SIGNEDSTATE_MISSING
// means that the signature cannot be relied upon. It is equivalent to
// removing the signature from the XPI file, which already causes them
// to be disabled on release builds (where MOZ_REQUIRE_SIGNING=true).
return false;
}
if (signedDate.getTime() > generationTime) {
// The bloom filter only reports 100% accurate results for known add-ons.
// Since the add-on was unknown when the bloom filter was generated, the
// block decision is incorrect and should be treated as unblocked.
return false;
}
if (AppConstants.NIGHTLY_BUILD && addon.type === "locale") {
// Only Mozilla can create langpacks with a valid signature.
// Langpacks for Release, Beta and ESR are submitted to AMO.
// (and built-in addons are not subjected to the blocklist).
// Langpacks for Nightly are not known to AMO, so the MLBF cannot be used.
return false;
}
// Addon found in the mlbfData and not exempted from blocks due to
// signature type and datetime, nor a langpack xpi installed on Nightly builds.
return true;
},
_createBlockEntry({ addon, softBlock = false }) {
return {
state: softBlock
? Ci.nsIBlocklistService.STATE_SOFTBLOCKED
: Ci.nsIBlocklistService.STATE_BLOCKED,
url: this.createBlocklistURL(addon.id, addon.version),
};
},
createBlocklistURL(id, version) {
let url = Services.urlFormatter.formatURLPref(PREF_BLOCKLIST_ADDONITEM_URL);
return url.replace(/%addonID%/g, id).replace(/%addonVersion%/g, version);
},
};
const EXTENSION_BLOCK_FILTERS = [
"id",
"name",
"creator",
"homepageURL",
"updateURL",
];
var gLoggingEnabled = null;
var gBlocklistEnabled = true;
var gBlocklistSoftBlockEnabled = true;
var gBlocklistLevel = DEFAULT_LEVEL;
/**
* @class nsIBlocklistPrompt
*
* nsIBlocklistPrompt is used, if available, by the default implementation of
* nsIBlocklistService to display a confirmation UI to the user before blocking
* extensions/plugins.
*/
/**
* @method prompt
*
* Prompt the user about newly blocked addons. The prompt is then resposible
* for soft-blocking any addons that need to be afterwards
*
* @param {object[]} aAddons
* An array of addons and plugins that are blocked. These are javascript
* objects with properties:
* name - the plugin or extension name,
* version - the version of the extension or plugin,
* icon - the plugin or extension icon,
* disable - can be used by the nsIBlocklistPrompt to allows users to decide
* whether a soft-blocked add-on should be disabled,
* blocked - true if the item is hard-blocked, false otherwise,
* item - the Addon object
*/
// It is not possible to use the one in Services 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.
ChromeUtils.defineLazyGetter(lazy, "gApp", function () {
// eslint-disable-next-line mozilla/use-services
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;
});
ChromeUtils.defineLazyGetter(lazy, "gAppID", function () {
return lazy.gApp.ID;
});
ChromeUtils.defineLazyGetter(lazy, "gAppOS", function () {
return lazy.gApp.OS;
});
/**
* Logs a string to the error console.
* @param {string} string
* The string to write to the error console..
*/
function LOG(string) {
if (gLoggingEnabled) {
dump("*** " + string + "\n");
Services.console.logStringMessage(string);
}
}
export let Blocklist = {
get isEnabled() {
return gBlocklistEnabled;
},
get isSoftBlockEnabled() {
return gBlocklistSoftBlockEnabled;
},
_init() {
Services.obs.addObserver(this, "xpcom-shutdown");
gLoggingEnabled = Services.prefs.getBoolPref(
PREF_EM_LOGGING_ENABLED,
false
);
gBlocklistSoftBlockEnabled = Services.prefs.getBoolPref(
PREF_BLOCKLIST_SOFTBLOCK_ENABLED,
true
);
gBlocklistEnabled = Services.prefs.getBoolPref(
PREF_BLOCKLIST_ENABLED,
true
);
gBlocklistLevel = Math.min(
Services.prefs.getIntPref(PREF_BLOCKLIST_LEVEL, DEFAULT_LEVEL),
MAX_BLOCK_LEVEL
);
this._chooseExtensionBlocklistImplementationFromPref();
Services.prefs.addObserver("extensions.blocklist.", this);
Services.prefs.addObserver(PREF_EM_LOGGING_ENABLED, this);
},
isLoaded: true,
shutdown() {
GfxBlocklistRS.shutdown();
this.ExtensionBlocklist.shutdown();
Services.obs.removeObserver(this, "xpcom-shutdown");
Services.prefs.removeObserver("extensions.blocklist.", this);
Services.prefs.removeObserver(PREF_EM_LOGGING_ENABLED, this);
},
observe(subject, topic, prefName) {
switch (topic) {
case "xpcom-shutdown":
this.shutdown();
break;
case "nsPref:changed":
switch (prefName) {
case PREF_EM_LOGGING_ENABLED:
gLoggingEnabled = Services.prefs.getBoolPref(
PREF_EM_LOGGING_ENABLED,
false
);
break;
case PREF_BLOCKLIST_ENABLED:
gBlocklistEnabled = Services.prefs.getBoolPref(
PREF_BLOCKLIST_ENABLED,
true
);
this._blocklistUpdated();
break;
case PREF_BLOCKLIST_SOFTBLOCK_ENABLED:
gBlocklistSoftBlockEnabled = Services.prefs.getBoolPref(
PREF_BLOCKLIST_SOFTBLOCK_ENABLED,
true
);
this._blocklistUpdated();
break;
case PREF_BLOCKLIST_LEVEL:
gBlocklistLevel = Math.min(
Services.prefs.getIntPref(PREF_BLOCKLIST_LEVEL, DEFAULT_LEVEL),
MAX_BLOCK_LEVEL
);
this._blocklistUpdated();
break;
case PREF_BLOCKLIST_USE_MLBF: {
let oldImpl = this.ExtensionBlocklist;
this._chooseExtensionBlocklistImplementationFromPref();
// The implementation may be unchanged when the pref is ignored.
if (oldImpl != this.ExtensionBlocklist && oldImpl._initialized) {
oldImpl.shutdown();
this.ExtensionBlocklist.undoShutdown();
this.ExtensionBlocklist._onUpdate();
} // else neither has been initialized yet. Wait for it to happen.
break;
}
}
break;
}
},
loadBlocklistAsync() {
// Need to ensure we notify gfx of new stuff.
// check for entries when first initialized.
if (!GfxBlocklistRS._initialized) {
GfxBlocklistRS.checkForEntries();
}
this.ExtensionBlocklist.ensureInitialized();
},
getAddonBlocklistState(addon, appVersion, toolkitVersion) {
// NOTE: appVersion/toolkitVersion are only used by ExtensionBlocklistRS.
return this.ExtensionBlocklist.getState(addon, appVersion, toolkitVersion);
},
getAddonBlocklistEntry(addon, appVersion, toolkitVersion) {
// NOTE: appVersion/toolkitVersion are only used by ExtensionBlocklistRS.
return this.ExtensionBlocklist.getEntry(addon, appVersion, toolkitVersion);
},
recordAddonBlockChangeTelemetry(addon, reason) {
BlocklistTelemetry.recordAddonBlockChangeTelemetry(addon, reason);
},
allowDeprecatedBlocklistV2: false,
_chooseExtensionBlocklistImplementationFromPref() {
if (
this.allowDeprecatedBlocklistV2 &&
!Services.prefs.getBoolPref(PREF_BLOCKLIST_USE_MLBF, false)
) {
this.ExtensionBlocklist = ExtensionBlocklistRS;
} else {
this.ExtensionBlocklist = ExtensionBlocklistMLBF;
}
},
_blocklistUpdated() {
this.ExtensionBlocklist._onUpdate();
},
};
Blocklist._init();
// Allow tests to reach implementation objects.
export const BlocklistPrivate = {
BlocklistTelemetry,
ExtensionBlocklistMLBF,
ExtensionBlocklistRS,
GfxBlocklistRS,
};