1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/**
* This file is part of Haketilo.
*
* Function: Main background script.
*
* Copyright (C) 2021 Wojtek Kosior
* Redistribution terms are gathered in the `copyright' file.
*/
/*
* IMPORTS_START
* IMPORT TYPE_PREFIX
* IMPORT get_storage
* IMPORT light_storage
* IMPORT start_storage_server
* IMPORT start_page_actions_server
* IMPORT browser
* IMPORT is_privileged_url
* IMPORT query_best
* IMPORT inject_csp_headers
* IMPORT apply_stream_filter
* IMPORT is_chrome
* IMPORT is_mozilla
* IMPORTS_END
*/
start_storage_server();
start_page_actions_server();
async function init_ext(install_details)
{
if (install_details.reason != "install")
return;
let storage = await get_storage();
await storage.clear();
/*
* Below we add sample settings to the extension.
*/
for (let setting of // The next line is replaced with the contents of /default_settings.json by the build script
`DEFAULT SETTINGS`
) {
let [key, value] = Object.entries(setting)[0];
storage.set(key[0], key.substring(1), value);
}
}
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 sanitize_web_page(details)
{
const url = details.url;
if (is_privileged_url(details.url))
return;
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*(;.*)$/i.test(header.value)))
skip = true;
}
skip = skip || (details.statusCode >= 300 && details.statusCode < 400);
if (!skip) {
/* Check for API availability. */
if (browser.webRequest.filterResponseData)
headers = apply_stream_filter(details, headers, policy);
}
return {responseHeaders: headers};
}
const request_url_regex = /^[^?]*\?url=(.*)$/;
const redirect_url_template = browser.runtime.getURL("dummy") + "?settings=";
function synchronously_smuggle_policy(details)
{
/*
* 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 = [
"main_frame", "sub_frame", "stylesheet", "script", "image", "font",
"object", "xmlhttprequest", "ping", "csp_report", "media", "websocket",
"other", "main_frame", "sub_frame"
];
async function start_webRequest_operations()
{
storage = await get_storage();
const extra_opts = ["blocking"];
if (is_chrome)
extra_opts.push("extraHeaders");
browser.webRequest.onHeadersReceived.addListener(
sanitize_web_page,
{urls: ["<all_urls>"], types: ["main_frame", "sub_frame"]},
extra_opts.concat("responseHeaders")
);
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();
|
