ma1 pushed to branch tor-browser-115.6.0esr-13.5-1 at The Tor Project / Applications / Tor Browser

Commits: d823a7e7 by hackademix at 2023-12-20T17:06:45+01:00 fixup! Bug 40458: Implement .tor.onion aliases

Bug 42099: Blind cross-site .onion requests.

- - - - -

3 changed files:

- browser/components/onionservices/OnionAliasStore.sys.mjs - + browser/components/onionservices/TorRequestWatch.sys.mjs - browser/components/onionservices/moz.build

Changes:

===================================== browser/components/onionservices/OnionAliasStore.sys.mjs ===================================== @@ -7,6 +7,7 @@ const lazy = {};

ChromeUtils.defineESModuleGetters(lazy, { JSONFile: "resource://gre/modules/JSONFile.sys.mjs", + TorRequestWatch: "resource:///modules/TorRequestWatch.sys.mjs", });

/* OnionAliasStore observer topics */ @@ -272,6 +273,7 @@ class _OnionAliasStore { }

async init() { + lazy.TorRequestWatch.start(); await this._loadSettings(); if (this.enabled) { await this._startUpdates(); @@ -286,6 +288,7 @@ class _OnionAliasStore { } this._rulesetTimeout = null; Services.prefs.removeObserver(kPrefOnionAliasEnabled, this); + lazy.TorRequestWatch.stop(); }

async getChannels() {

===================================== browser/components/onionservices/TorRequestWatch.sys.mjs ===================================== @@ -0,0 +1,124 @@ +/* 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/. */ + +/* + * This module implements Tor-specific Web Request policies, such as + * preventing observable cross-site requests to .tor.onion and .bit.onion sites. + */ + +import { ConsoleAPI } from "resource://gre/modules/Console.sys.mjs"; + +const log = new ConsoleAPI({ + maxLogLevel: "warn", + maxLogLevelPref: "browser.torRequestWatch.log_level", + prefix: "TorRequestWatch", +}); + +class RequestObserver { + static #topics = [ + "http-on-modify-request", + "http-on-examine-response", + "http-on-examine-cached-response", + "http-on-examine-merged-response", + ]; + #asObserver(addOrRemove) { + const action = Services.obs[`${addOrRemove}Observer`].bind(Services.obs); + for (const topic of RequestObserver.#topics) { + action(this, topic); + } + } + + start() { + this.#asObserver("add"); + log.debug("Started"); + } + stop() { + this.#asObserver("remove"); + log.debug("Stopped"); + } + + // nsIObserver implementation + observe(subject, topic, data) { + try { + let channel = ChannelWrapper.get( + subject.QueryInterface(Ci.nsIHttpChannel) + ); + switch (topic) { + case "http-on-modify-request": + this.onRequest(channel); + break; + case "http-on-examine-cached-response": + case "http-on-examine-merged-response": + channel.isCached = true; + // falls through + case "http-on-examine-response": + this.onResponse(channel); + break; + } + } catch (e) { + log.error(e); + } + } + + onRequest(channel) { + if (this.shouldBlind(channel, channel.documentURL)) { + log.warn(`Blocking cross-site ${channel.finalURL} ${channel.type} load.`); + channel.cancel(Cr.NS_ERROR_ABORT); + } + } + onResponse(channel) { + if (!channel.documentURL && this.shouldBlind(channel, channel.originURL)) { + const COOP = "cross-origin-opener-policy"; + // we break window.opener references if needed to mitigate XS-Leaks + for (let h of channel.getResponseHeaders()) { + if (h.name.toLowerCase() === COOP && h.value === "same-origin") { + log.debug(`${COOP} is already same-origin, nothing to do.`); + return; + } + } + log.warn(`Blinding cross-site ${channel.finalURL} load.`); + channel.setResponseHeader(COOP, "same-origin-allow-popups"); + } + } + + isCrossOrigin(url1, url2) { + return new URL(url1).origin !== new URL(url2).origin; + } + shouldBlindCrossOrigin(uri) { + try { + let { host } = uri; + if (host.endsWith(".onion")) { + const previousPart = host.slice(-10, -6); + return ( + previousPart && (previousPart === ".tor" || previousPart === ".bit") + ); + } + } catch (e) { + // no host + } + return false; + } + shouldBlind(channel, sourceURL) { + return ( + sourceURL && + this.shouldBlindCrossOrigin(channel.finalURI) && + this.isCrossOrigin(channel.finalURL, sourceURL) + ); + } +} + +let observer; +export const TorRequestWatch = { + start() { + if (!observer) { + (observer = new RequestObserver()).start(); + } + }, + stop() { + if (observer) { + observer.stop(); + observer = null; + } + }, +};

===================================== browser/components/onionservices/moz.build ===================================== @@ -4,4 +4,5 @@ EXTRA_JS_MODULES += [ "OnionAliasStore.sys.mjs", "OnionLocationChild.sys.mjs", "OnionLocationParent.sys.mjs", + "TorRequestWatch.sys.mjs", ]

View it on GitLab: https://gitlab.torproject.org/tpo/applications/tor-browser/-/commit/d823a7e7...