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-rw-r--r--background/cookie_filter.js46
-rw-r--r--background/main.js120
-rw-r--r--background/page_actions_server.js32
-rw-r--r--background/policy_injector.js67
-rw-r--r--background/stream_filter.js6
5 files changed, 115 insertions, 156 deletions
diff --git a/background/cookie_filter.js b/background/cookie_filter.js
deleted file mode 100644
index 64d18b2..0000000
--- a/background/cookie_filter.js
+++ /dev/null
@@ -1,46 +0,0 @@
-/**
- * This file is part of Haketilo.
- *
- * Function: Filtering request headers to remove haketilo cookies that might
- * have slipped through.
- *
- * Copyright (C) 2021 Wojtek Kosior
- * Redistribution terms are gathered in the `copyright' file.
- */
-
-/*
- * IMPORTS_START
- * IMPORT extract_signed
- * IMPORTS_END
- */
-
-function is_valid_haketilo_cookie(cookie)
-{
- const match = /^haketilo-(\w*)=(.*)$/.exec(cookie);
- if (!match)
- return false;
-
- return !extract_signed(match.slice(1, 3)).fail;
-}
-
-function remove_haketilo_cookies(header)
-{
- if (header.name !== "Cookie")
- return header;
-
- const cookies = header.value.split("; ");
- const value = cookies.filter(c => !is_valid_haketilo_cookie(c)).join("; ");
-
- return value ? {name: "Cookie", value} : null;
-}
-
-function filter_cookie_headers(headers)
-{
- return headers.map(remove_haketilo_cookies).filter(h => h);
-}
-
-/*
- * EXPORTS_START
- * EXPORT filter_cookie_headers
- * EXPORTS_END
- */
diff --git a/background/main.js b/background/main.js
index 40b3a9e..9cdfb97 100644
--- a/background/main.js
+++ b/background/main.js
@@ -17,11 +17,10 @@
* IMPORT browser
* IMPORT is_privileged_url
* IMPORT query_best
- * IMPORT gen_nonce
* IMPORT inject_csp_headers
* IMPORT apply_stream_filter
- * IMPORT filter_cookie_headers
* IMPORT is_chrome
+ * IMPORT is_mozilla
* IMPORTS_END
*/
@@ -51,34 +50,53 @@ async function init_ext(install_details)
browser.runtime.onInstalled.addListener(init_ext);
+/*
+ * The function below implements a more practical interface for what it does by
+ * wrapping the old query_best() function.
+ */
+function decide_policy_for_url(storage, policy_observable, url)
+{
+ if (storage === undefined)
+ return {allow: false};
+
+ const settings =
+ {allow: policy_observable !== undefined && policy_observable.value};
+
+ const [pattern, queried_settings] = query_best(storage, url);
+
+ if (queried_settings) {
+ settings.payload = queried_settings.components;
+ settings.allow = !!queried_settings.allow && !settings.payload;
+ settings.pattern = pattern;
+ }
+
+ return settings;
+}
let storage;
let policy_observable = {};
-function on_headers_received(details)
+function sanitize_web_page(details)
{
const url = details.url;
if (is_privileged_url(details.url))
return;
- const [pattern, settings] = query_best(storage, details.url);
- const has_payload = !!(settings && settings.components);
- const allow = !has_payload &&
- !!(settings ? settings.allow : policy_observable.value);
- const nonce = gen_nonce();
- const policy = {allow, url, nonce, has_payload};
+ const policy =
+ decide_policy_for_url(storage, policy_observable, details.url);
let headers = details.responseHeaders;
+
+ headers = inject_csp_headers(headers, policy);
+
let skip = false;
for (const header of headers) {
if ((header.name.toLowerCase().trim() === "content-disposition" &&
/^\s*attachment\s*(;.*)$/i.test(header.value)))
skip = true;
}
-
- headers = inject_csp_headers(headers, policy);
-
skip = skip || (details.statusCode >= 300 && details.statusCode < 400);
+
if (!skip) {
/* Check for API availability. */
if (browser.webRequest.filterResponseData)
@@ -88,11 +106,49 @@ function on_headers_received(details)
return {responseHeaders: headers};
}
-function on_before_send_headers(details)
+const request_url_regex = /^[^?]*\?url=(.*)$/;
+const redirect_url_template = browser.runtime.getURL("dummy") + "?settings=";
+
+function synchronously_smuggle_policy(details)
{
- let headers = details.requestHeaders;
- headers = filter_cookie_headers(headers);
- return {requestHeaders: headers};
+ /*
+ * Content script will make a synchronous XmlHttpRequest to extension's
+ * `dummy` file to query settings for given URL. We smuggle that
+ * information in query parameter of the URL we redirect to.
+ * A risk of fingerprinting arises if a page with script execution allowed
+ * guesses the dummy file URL and makes an AJAX call to it. It is currently
+ * a problem in ManifestV2 Chromium-family port of Haketilo because Chromium
+ * uses predictable URLs for web-accessible resources. We plan to fix it in
+ * the future ManifestV3 port.
+ */
+ if (details.type !== "xmlhttprequest")
+ return {cancel: true};
+
+ console.debug(`Settings queried using XHR for '${details.url}'.`);
+
+ let policy = {allow: false};
+
+ try {
+ /*
+ * request_url should be of the following format:
+ * <url_for_extension's_dummy_file>?url=<valid_urlencoded_url>
+ */
+ const match = request_url_regex.exec(details.url);
+ const queried_url = decodeURIComponent(match[1]);
+
+ if (details.initiator && !queried_url.startsWith(details.initiator)) {
+ console.warn(`Blocked suspicious query of '${url}' by '${details.initiator}'. This might be the result of page fingerprinting the browser.`);
+ return {cancel: true};
+ }
+
+ policy = decide_policy_for_url(storage, policy_observable, queried_url);
+ } catch (e) {
+ console.warn(`Bad request! Expected ${browser.runtime.getURL("dummy")}?url=<valid_urlencoded_url>. Got ${request_url}. This might be the result of page fingerprinting the browser.`);
+ }
+
+ const encoded_policy = encodeURIComponent(JSON.stringify(policy));
+
+ return {redirectUrl: redirect_url_template + encoded_policy};
}
const all_types = [
@@ -110,18 +166,40 @@ async function start_webRequest_operations()
extra_opts.push("extraHeaders");
browser.webRequest.onHeadersReceived.addListener(
- on_headers_received,
+ sanitize_web_page,
{urls: ["<all_urls>"], types: ["main_frame", "sub_frame"]},
extra_opts.concat("responseHeaders")
);
- browser.webRequest.onBeforeSendHeaders.addListener(
- on_before_send_headers,
- {urls: ["<all_urls>"], types: all_types},
- extra_opts.concat("requestHeaders")
+ const dummy_url_pattern = browser.runtime.getURL("dummy") + "?url=*";
+ browser.webRequest.onBeforeRequest.addListener(
+ synchronously_smuggle_policy,
+ {urls: [dummy_url_pattern], types: ["xmlhttprequest"]},
+ extra_opts
);
policy_observable = await light_storage.observe_var("default_allow");
}
start_webRequest_operations();
+
+const code = `\
+console.warn("Hi, I'm Mr Dynamic!");
+
+console.debug("let's see how window.killtheweb looks like now");
+
+console.log("killtheweb", window.killtheweb);
+`
+
+async function test_dynamic_content_scripts()
+{
+ browser.contentScripts.register({
+ "js": [{code}],
+ "matches": ["<all_urls>"],
+ "allFrames": true,
+ "runAt": "document_start"
+});
+}
+
+if (is_mozilla)
+ test_dynamic_content_scripts();
diff --git a/background/page_actions_server.js b/background/page_actions_server.js
index 156a79f..74783c9 100644
--- a/background/page_actions_server.js
+++ b/background/page_actions_server.js
@@ -16,34 +16,12 @@
* IMPORT browser
* IMPORT listen_for_connection
* IMPORT sha256
- * IMPORT query_best
* IMPORT make_ajax_request
* IMPORTS_END
*/
var storage;
var handler;
-let policy_observable;
-
-function send_actions(url, port)
-{
- const [pattern, queried_settings] = query_best(storage, url);
-
- const settings = {allow: policy_observable && policy_observable.value};
- Object.assign(settings, queried_settings);
- if (settings.components)
- settings.allow = false;
-
- const repos = storage.get_all(TYPE_PREFIX.REPO);
-
- port.postMessage(["settings", [pattern, settings, repos]]);
-
- const components = settings.components;
- const processed_bags = new Set();
-
- if (components !== undefined)
- send_scripts([components], port, processed_bags);
-}
// TODO: parallelize script fetching
async function send_scripts(components, port, processed_bags)
@@ -116,9 +94,11 @@ async function fetch_remote_script(script_data)
function handle_message(port, message, handler)
{
port.onMessage.removeListener(handler[0]);
- let url = message.url;
- console.log({url});
- send_actions(url, port);
+ console.debug(`Loading payload '${message.payload}'.`);
+
+ const processed_bags = new Set();
+
+ send_scripts([message.payload], port, processed_bags);
}
function new_connection(port)
@@ -134,8 +114,6 @@ async function start_page_actions_server()
storage = await get_storage();
listen_for_connection(CONNECTION_TYPE.PAGE_ACTIONS, new_connection);
-
- policy_observable = await light_storage.observe_var("default_allow");
}
/*
diff --git a/background/policy_injector.js b/background/policy_injector.js
index 881595b..b49ec47 100644
--- a/background/policy_injector.js
+++ b/background/policy_injector.js
@@ -10,77 +10,28 @@
/*
* IMPORTS_START
- * IMPORT sign_data
- * IMPORT extract_signed
* IMPORT make_csp_rule
* IMPORT csp_header_regex
+ * Re-enable the import below once nonce stuff here is ready
+ * !mport gen_nonce
* IMPORTS_END
*/
function inject_csp_headers(headers, policy)
{
let csp_headers;
- let old_signature;
- let haketilo_header;
- for (const header of headers.filter(h => h.name === "x-haketilo")) {
- /* x-haketilo header has format: <signature>_0_<data> */
- const match = /^([^_]+)_(0_.*)$/.exec(header.value);
- if (!match)
- continue;
+ if (policy.payload) {
+ headers = headers.filter(h => !csp_header_regex.test(h.name));
- const result = extract_signed(...match.slice(1, 3));
- if (result.fail)
- continue;
+ // TODO: make CSP rules with nonces and facilitate passing them to
+ // content scripts via dynamic content script registration or
+ // synchronous XHRs
- /* This should succeed - it's our self-produced valid JSON. */
- const old_data = JSON.parse(decodeURIComponent(result.data));
-
- /* Confirmed- it's the originals, smuggled in! */
- csp_headers = old_data.csp_headers;
- old_signature = old_data.policy_sig;
-
- haketilo_header = header;
- break;
+ // policy.nonce = gen_nonce();
}
- if (policy.has_payload) {
- csp_headers = [];
- const non_csp_headers = [];
- const header_list =
- h => csp_header_regex.test(h) ? csp_headers : non_csp_headers;
- headers.forEach(h => header_list(h.name).push(h));
- headers = non_csp_headers;
- } else {
- headers.push(...csp_headers || []);
- }
-
- if (!haketilo_header) {
- haketilo_header = {name: "x-haketilo"};
- headers.push(haketilo_header);
- }
-
- if (old_signature)
- headers = headers.filter(h => h.value.search(old_signature) === -1);
-
- const policy_str = encodeURIComponent(JSON.stringify(policy));
- const signed_policy = sign_data(policy_str, new Date().getTime());
- const later_30sec = new Date(new Date().getTime() + 30000).toGMTString();
- headers.push({
- name: "Set-Cookie",
- value: `haketilo-${signed_policy.join("=")}; Expires=${later_30sec};`
- });
-
- /*
- * Smuggle in the signature and the original CSP headers for future use.
- * These are signed with a time of 0, as it's not clear there is a limit on
- * how long Firefox might retain headers in the cache.
- */
- let haketilo_data = {csp_headers, policy_sig: signed_policy[0]};
- haketilo_data = encodeURIComponent(JSON.stringify(haketilo_data));
- haketilo_header.value = sign_data(haketilo_data, 0).join("_");
-
- if (!policy.allow) {
+ if (!policy.allow && (policy.nonce || !policy.payload)) {
headers.push({
name: "content-security-policy",
value: make_csp_rule(policy)
diff --git a/background/stream_filter.js b/background/stream_filter.js
index e5e0827..e5d124c 100644
--- a/background/stream_filter.js
+++ b/background/stream_filter.js
@@ -174,8 +174,7 @@ function filter_data(properties, event)
* as harmless anyway).
*/
- const dummy_script =
- `<script data-haketilo-deleteme="${properties.policy.nonce}" nonce="${properties.policy.nonce}">null</script>`;
+ const dummy_script = `<script>null</script>`;
const doctype_decl = /^(\s*<!doctype[^<>"']*>)?/i.exec(decoded)[0];
decoded = doctype_decl + dummy_script +
decoded.substring(doctype_decl.length);
@@ -189,11 +188,10 @@ function filter_data(properties, event)
function apply_stream_filter(details, headers, policy)
{
- if (!policy.has_payload)
+ if (!policy.payload)
return headers;
const properties = properties_from_headers(headers);
- properties.policy = policy;
properties.filter =
browser.webRequest.filterResponseData(details.requestId);