Files
MasterHttpRelayVPN-RUST/assets/apps_script/Code.gs
T
therealaleph cb3732f920 feat: v1.8.0 — DPI evasion, active-probing defense, full-mode usage counters
Five user-visible changes shipping together. Each is independently
useful + bounded; bundled because they're all "small architectural
hardening" that benefits from one release announcement.

1. Random payload padding (#313, #365 §1)

   Every outbound Apps Script JSON request now carries a `_pad` field
   of uniform-random length 0..1024 bytes (base64). Defeats DPI that
   fingerprints on the tight length distribution of mhrv-rs's previous
   per-mode-bound packet sizes. ~25% bandwidth on a typical 2 KB batch,
   negligible against Apps Script's per-call latency floor. Backward-
   compatible — old `Code.gs` deployments ignore the unknown field.
   Applied at all three payload-build sites: single relay, single
   tunnel op, batch tunnel.

2. Active-probing decoy: GAS bad-auth → 200 HTML (#365 §3)

   `Code.gs` and `CodeFull.gs` now return a benign Apps-Script-style
   placeholder HTML page on bad/missing AUTH_KEY instead of the JSON
   `{"e":"unauthorized"}`. To an active scanner the deployment looks
   like one of the millions of forgotten public Apps Script projects
   rather than an obvious API endpoint. New `DIAGNOSTIC_MODE` const
   restores JSON errors during setup; default false (production-strong).

3. Active-probing decoy: tunnel-node bad-auth → 404 nginx (#365 §3)

   `tunnel-node` returns an HTTP 404 with an nginx-style HTML body on
   bad auth instead of `{"e":"unauthorized"}`. Active scanners cataloging
   the host see "static web server, nothing tunnel-shaped here." New
   `MHRV_DIAGNOSTIC=1` env var restores verbose JSON during setup.

4. Fix: Full-mode usage counter stuck at zero (#230, #362)

   `today_calls` / `today_bytes` were only being incremented on the
   apps_script-mode relay path. Full-mode batches go through
   `tunnel_client::fire_batch` which never wired into the counter.
   Now `fire_batch` calls `record_today(response_bytes)` after each
   successful batch — bytes estimated from the `d` (TCP payload) and
   `pkts` (UDP datagrams) sizes in the BatchTunnelResponse. Full-mode
   users now see real usage numbers.

5. Fix: quota reset countdown was UTC, should be PT (#230, #362)

   Apps Script's UrlFetchApp daily quota resets at midnight Pacific
   Time, not UTC. We were displaying the countdown to UTC midnight,
   off by 7-8h depending on DST. New `current_pt_day_key()` and
   `seconds_until_pacific_midnight()` helpers with hand-rolled US DST
   detection (2nd Sunday March → 1st Sunday November = PDT, else PST)
   so we don't pull `chrono-tz` and a ~3 MB IANA tzdb just for one
   helper. UI label "UTC day" → "PT day". Tests pin DST window
   boundaries against March/November of 2024, 2026, 2027 to catch
   regressions in the day-of-week math.

Tested:
- cargo test --lib: 154 passed (was 152, +2 for DST window + day-of-week)
- cargo build --release: clean
- cargo build --release --bin mhrv-rs-ui --features ui: clean (macOS arm64)
- tunnel-node cargo test: 30 passed
- Android: ./gradlew assembleDebug succeeds; APK installs + launches
  on mhrv_test emulator (arm64-v8a), no UnsatisfiedLink, no crash

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-28 01:39:47 +03:00

183 lines
5.6 KiB
JavaScript

/**
* DomainFront Relay — Google Apps Script
*
* TWO modes:
* 1. Single: POST { k, m, u, h, b, ct, r } → { s, h, b }
* 2. Batch: POST { k, q: [{m,u,h,b,ct,r}, ...] } → { q: [{s,h,b}, ...] }
* Uses UrlFetchApp.fetchAll() — all URLs fetched IN PARALLEL.
*
* DEPLOYMENT:
* 1. Go to https://script.google.com → New project
* 2. Delete the default code, paste THIS entire file
* 3. Click Deploy → New deployment
* 4. Type: Web app | Execute as: Me | Who has access: Anyone
* 5. Copy the Deployment ID into config.json as "script_id"
*
* CHANGE THE AUTH KEY BELOW TO YOUR OWN SECRET!
*/
const AUTH_KEY = "CHANGE_ME_TO_A_STRONG_SECRET";
// Active-probing defense. When false (production default), bad AUTH_KEY
// requests get a decoy HTML page that looks like a placeholder Apps
// Script web app instead of the JSON `{"e":"unauthorized"}` body. This
// makes the deployment indistinguishable from a forgotten-but-public
// Apps Script project to active scanners that POST malformed payloads
// looking for proxy endpoints.
//
// Set to `true` during initial setup if a misconfigured client is
// hitting "unauthorized" and you want the explicit JSON error to debug
// — then flip back to false before the deployment is widely shared.
// (Inspired by #365 Section 3, mhrv-rs v1.8.0+.)
const DIAGNOSTIC_MODE = false;
// Keep browser capability headers (sec-ch-ua*, sec-fetch-*) intact.
// Some modern apps, notably Google Meet, use them for browser gating.
const SKIP_HEADERS = {
host: 1, connection: 1, "content-length": 1,
"transfer-encoding": 1, "proxy-connection": 1, "proxy-authorization": 1,
"priority": 1, te: 1,
};
// HTML body for the bad-auth decoy. Mimics a minimal Apps Script-style
// placeholder page — no proxy-shaped JSON, nothing distinctive enough
// for a probe to fingerprint as a tunnel endpoint.
const DECOY_HTML =
'<!DOCTYPE html><html><head><title>Web App</title></head>' +
'<body><p>The script completed but did not return anything.</p>' +
'</body></html>';
function _decoyOrError(jsonBody) {
if (DIAGNOSTIC_MODE) return _json(jsonBody);
return ContentService
.createTextOutput(DECOY_HTML)
.setMimeType(ContentService.MimeType.HTML);
}
function doPost(e) {
try {
var req = JSON.parse(e.postData.contents);
if (req.k !== AUTH_KEY) return _decoyOrError({ e: "unauthorized" });
// Batch mode: { k, q: [...] }
if (Array.isArray(req.q)) return _doBatch(req.q);
// Single mode
return _doSingle(req);
} catch (err) {
// Parse failures of the request body are also probe-shaped — a real
// mhrv-rs client never sends invalid JSON. Decoy for the same reason.
return _decoyOrError({ e: String(err) });
}
}
// `doGet` is what active scanners hit first (HTTP GET probes are cheaper
// than POSTs). Apps Script defaults to a "Script function not found" page
// here which is a fine-enough decoy on its own, but explicitly returning
// the same harmless placeholder makes the response identical to the
// bad-auth POST decoy — one less fingerprint vector.
function doGet(e) {
return ContentService
.createTextOutput(DECOY_HTML)
.setMimeType(ContentService.MimeType.HTML);
}
function _doSingle(req) {
if (!req.u || typeof req.u !== "string" || !req.u.match(/^https?:\/\//i)) {
return _json({ e: "bad url" });
}
var opts = _buildOpts(req);
var resp = UrlFetchApp.fetch(req.u, opts);
return _json({
s: resp.getResponseCode(),
h: _respHeaders(resp),
b: Utilities.base64Encode(resp.getContent()),
});
}
function _doBatch(items) {
var fetchArgs = [];
var errorMap = {};
for (var i = 0; i < items.length; i++) {
var item = items[i];
if (!item.u || typeof item.u !== "string" || !item.u.match(/^https?:\/\//i)) {
errorMap[i] = "bad url";
continue;
}
var opts = _buildOpts(item);
opts.url = item.u;
fetchArgs.push({ _i: i, _o: opts });
}
// fetchAll() processes all requests in parallel inside Google
var responses = [];
if (fetchArgs.length > 0) {
responses = UrlFetchApp.fetchAll(fetchArgs.map(function(x) { return x._o; }));
}
var results = [];
var rIdx = 0;
for (var i = 0; i < items.length; i++) {
if (errorMap.hasOwnProperty(i)) {
results.push({ e: errorMap[i] });
} else {
var resp = responses[rIdx++];
results.push({
s: resp.getResponseCode(),
h: _respHeaders(resp),
b: Utilities.base64Encode(resp.getContent()),
});
}
}
return _json({ q: results });
}
function _buildOpts(req) {
var opts = {
method: (req.m || "GET").toLowerCase(),
muteHttpExceptions: true,
followRedirects: req.r !== false,
validateHttpsCertificates: true,
escaping: false,
};
if (req.h && typeof req.h === "object") {
var headers = {};
for (var k in req.h) {
if (req.h.hasOwnProperty(k) && !SKIP_HEADERS[k.toLowerCase()]) {
headers[k] = req.h[k];
}
}
opts.headers = headers;
}
if (req.b) {
opts.payload = Utilities.base64Decode(req.b);
if (req.ct) opts.contentType = req.ct;
}
return opts;
}
function _respHeaders(resp) {
try {
if (typeof resp.getAllHeaders === "function") {
return resp.getAllHeaders();
}
} catch (err) {}
return resp.getHeaders();
}
function doGet(e) {
return HtmlService.createHtmlOutput(
"<!DOCTYPE html><html><head><title>My App</title></head>" +
'<body style="font-family:sans-serif;max-width:600px;margin:40px auto">' +
"<h1>Welcome</h1><p>This application is running normally.</p>" +
"</body></html>"
);
}
function _json(obj) {
return ContentService.createTextOutput(JSON.stringify(obj)).setMimeType(
ContentService.MimeType.JSON
);
}