Files
ihasmail-inbuxa/server/src/app.ts
T
jcoffey-dev cdd8fabff9 No address step before signing in when there's only one mail server
The server's own page asks for the username, so with a single server the
sign-in page keeps only the own-device choice. With several servers the
address still comes first, since its domain picks the server. One new string,
in all nine catalogues.
2026-09-18 15:51:54 -07:00

1434 lines
62 KiB
TypeScript

import { Hono } from "hono";
import type { Context, MiddlewareHandler } from "hono";
import { getCookie, setCookie, deleteCookie } from "hono/cookie";
import { bodyLimit } from "hono/body-limit";
import { compress } from "hono/compress";
import { request as httpRequest } from "node:http";
import { request as httpsRequest } from "node:https";
import { RESPONSE_ALREADY_SENT } from "@hono/node-server/utils/response";
import { attach as pushAttach, attachRelay as pushAttachRelay, prepare as pushPrepare, receive as pushReceive, pushStatus } from "./push.js";
import { getConnInfo } from "@hono/node-server/conninfo";
import { config } from "./config.js";
import { fetchPermissions } from "./permissionSchema.js";
import { administrationAllowed, gateAdministration, grantsAdministration } from "./adminGate.js";
import { SessionStore, accountKey, type SessionBackend, type LiveSession } from "./sessions.js";
import { RateLimiter } from "./ratelimit.js";
import { rateLimitKey, resolveClientIp } from "./clientip.js";
import { safeEqual } from "./crypto.js";
import {
type AccountInfo,
UpstreamError,
absoluteUpstream,
expandTemplate,
fetchUpstreamSession,
hasStalwartRegistry,
forgetUpstreamSession,
getAccountInfo,
getUpstreamSession,
upstreamFor,
adminUrlFor,
localizeSession,
} from "./upstream.js";
import {
AccountError,
assertEnrollmentCode,
beginOtpEnrollment,
changePassword,
createAppPassword,
disableOtp,
enableOtp,
getState,
revokeAppPassword,
} from "./account.js";
import { imageProxyHandler } from "./imageproxy.js";
import { SignInError, finish as finishSignIn, needsRefresh, oauthEnabled, refreshTokens, singleServer, start as startSignIn, type TokenSet } from "./oauth.js";
import { icsProxyHandler } from "./icsproxy.js";
import { staticHandler } from "./static.js";
type Env = { Variables: { session: LiveSession } };
export const sessions: SessionBackend = new SessionStore(config.sessionFile);
const loginLimiter = new RateLimiter(config.loginRateLimit, 15 * 60_000);
/*
* The backstop that is never refunded.
*
* `loginLimiter` guards password guessing and gives its attempts back when the
* upstream never judged the password (#239) -- otherwise retrying through an
* outage locks somebody out until after it has ended. But "not counted" cannot
* mean "unlimited": each attempt still costs ihasmail an outbound connection
* that may sit there until `UPSTREAM_TIMEOUT`, so a flood during an outage is
* the one moment the endpoint is cheapest to abuse.
*
* Hence a second ceiling, per address, twenty times looser and refunded never.
* A person retrying an outage will not come near it; something hammering will.
*/
const loginFloodLimiter = new RateLimiter(config.loginRateLimit * 20, 15 * 60_000);
/**
* Credential changes verify the current password upstream, and Stalwart's
* fail2ban counts those failures against the *caller's* IP — which for a proxy
* is shared by every user. Keep our own lid on it so one person guessing
* cannot get the whole deployment banned.
*/
const accountLimiter = new RateLimiter(10, 15 * 60_000);
const apiLimiter = new RateLimiter(config.apiRateLimit, 60_000);
/** Per-session budget on the data path. See config.apiRateLimit. */
const apiRateLimited: MiddlewareHandler<Env> = async (c, next) => {
if (config.apiRateLimit > 0) {
const session = c.get("session");
if (session && !apiLimiter.check(session.id)) {
c.header("Retry-After", String(apiLimiter.retryAfterSeconds(session.id)));
return c.json({ error: "rate_limited" }, 429);
}
}
await next();
};
const HOP_BY_HOP = new Set([
"connection",
"keep-alive",
"proxy-authenticate",
"proxy-authorization",
"te",
"trailer",
"transfer-encoding",
"upgrade",
"content-encoding",
"content-length",
]);
export function clientIp(c: Context): string {
let peer = "unknown";
try {
peer = getConnInfo(c).remote.address ?? "unknown";
} catch {
/* no socket information available */
}
return resolveClientIp(peer, { forwardedFor: c.req.header("x-forwarded-for"), realIp: c.req.header("x-real-ip") }, config);
}
function isSecureRequest(c: Context): boolean {
if (config.secureCookies === "1" || config.secureCookies === "true") return true;
if (config.secureCookies === "0" || config.secureCookies === "false") return false;
if (config.trustProxy) {
const proto = c.req.header("x-forwarded-proto");
if (proto) return proto.split(",")[0]!.trim() === "https";
}
return new URL(c.req.url).protocol === "https:";
}
/** Security headers for every response. */
const securityHeaders: MiddlewareHandler = async (c, next) => {
await next();
const h = c.res.headers;
h.set("X-Content-Type-Options", "nosniff");
/* A route that must be framable says so; everything else is DENY. The blob
route is the only one, and only for PDFs -- see the note there. */
if (!h.has("X-Frame-Options")) h.set("X-Frame-Options", "DENY");
h.set("Referrer-Policy", "no-referrer");
h.set("Permissions-Policy", "camera=(), microphone=(), geolocation=(), payment=(), usb=()");
h.set("Cross-Origin-Opener-Policy", "same-origin");
if (!h.has("Cache-Control")) h.set("Cache-Control", "no-store");
if (isSecureRequest(c)) h.set("Strict-Transport-Security", "max-age=31536000; includeSubDomains");
};
/** CSRF: require our custom header on all API calls; reject cross-site fetches. */
/**
* Routes that forward somebody else's bytes rather than producing our own.
*
* Compression is right for the app shell, the bundle and our JSON; it is not
* worth the risk on the proxy paths. Those carry a content-length copied from
* upstream under the rules in `forwardedContentLength`, and issue #76 was a
* silent truncation caused by exactly that header disagreeing with the body.
* Re-encoding them would be safe in principle -- the length is dropped and the
* response goes out chunked -- but the payloads are attachments, images and
* calendar data that are already compressed or too small to matter, so there
* is nothing to win and a scar to respect.
*
* `/api/events` needs no entry here: Hono skips `text/event-stream` by content
* type. It is listed anyway, because a future change to that route's type
* should not quietly start buffering the push stream.
*/
const UNCOMPRESSED_ROUTES = [
"/api/blob/",
"/api/image",
"/api/ics",
"/api/upload/",
"/api/events",
/*
* The liveness probe, which is small enough that gzip makes it bigger: 53
* bytes becomes 73. Hono's size threshold cannot catch this on its own,
* because it only applies when the response carries a content-length and
* `c.json()` does not set one. Every other JSON route is left compressed --
* a JMAP response can run to hundreds of kilobytes and its length is just as
* unknown -- so this is the one place worth naming.
*/
"/api/health",
];
/**
* gzip for what we generate.
*
* The bundle ships uncompressed otherwise: 915 KB on the wire where 307 KB
* would do, on every first load. `Caddyfile.example` and
* `nginx.example.conf` both compress at the proxy, but that only helps the
* deployments that use them, and the default should not depend on reading the
* examples.
*
* Hono's middleware declines anything already carrying `Content-Encoding` or
* `Transfer-Encoding`, so a proxy compressing in front of us wins and we do
* not double-encode.
*/
function compressResponses(basePath: string): MiddlewareHandler {
const inner = compress({ threshold: 1024 });
const skip = UNCOMPRESSED_ROUTES.map((r) => `${basePath}${r}`);
if (!config.compressJmap) skip.push(`${basePath}/api/jmap`);
const offersEncoding = /\b(gzip|deflate)\b/i;
return async (c, next) => {
/*
* A client that did not ask for an encoding must not pay for one. Hono's
* middleware still inspects and re-labels every compressible response it
* declines -- setting Vary forces a streamed passthrough to be rebuilt off
* its fast path -- and that was measured at 1.2 ms per JMAP call, on a
* 1.9 ms operation, for a request that never sent Accept-Encoding.
*/
if (!offersEncoding.test(c.req.header("accept-encoding") ?? "")) return next();
const path = new URL(c.req.url).pathname;
if (skip.some((prefix) => path.startsWith(prefix))) return next();
return inner(c, next);
};
}
const csrfGuard: MiddlewareHandler = async (c, next) => {
// The mail server's sign-in page sends the browser back here, so this one
// arrives cross-site by design. Its state, bound to a cookie, stands in.
if (c.req.method === "GET" && c.req.path.endsWith("/api/auth/callback")) return next();
const site = c.req.header("sec-fetch-site");
if (site && site !== "same-origin" && site !== "none") {
return c.json({ error: "cross_site_request" }, 403);
}
if (c.req.method !== "GET" && c.req.method !== "HEAD") {
if (c.req.header("x-requested-with") !== "ihasmail") {
return c.json({ error: "missing_csrf_header" }, 403);
}
}
await next();
};
/**
* The largest body an API route that reads JSON will take.
*
* Hono reads a JSON body whole, and before this nothing bounded it: a few
* unauthenticated sign-in attempts carrying hundreds of megabytes each could
* run the process out of memory, and a restart signs everybody out. What
* these routes actually receive is a username and password, or a code.
*
* JMAP and uploads carry real payloads and bound themselves as they stream;
* the push callback has its own limit ahead of this one.
*/
const MAX_SMALL_BODY = 64 * 1024;
const LARGE_BODY_ROUTE = /\/api\/(jmap$|upload\/)/;
const limitSmallBody = bodyLimit({ maxSize: MAX_SMALL_BODY, onError: (c) => c.json({ error: "too_large" }, 413) });
const smallBodies: MiddlewareHandler = (c, next) => (LARGE_BODY_ROUTE.test(c.req.path) ? next() : limitSmallBody(c, next));
const requireSession: MiddlewareHandler<Env> = async (c, next) => {
const cookie = getCookie(c, config.cookieName);
let session = sessions.resolve(cookie);
if (session?.tokens && needsRefresh(session.tokens)) {
try {
session = await refreshSession(cookie!, session);
} catch (err) {
// Couldn't ask the server. The token may still have a few minutes; if
// not, the call itself will say so.
console.warn("[ihasmail] token refresh failed:", (err as Error).message);
}
if (!session) {
deleteCookie(c, config.cookieName, { path: cookiePath });
return c.json({ error: "unauthenticated" }, 401);
}
}
if (!session) {
return c.json({ error: "unauthenticated" }, 401);
}
c.set("session", session);
await next();
};
/*
* One refresh per session at a time: a page opening does several requests at
* once, and each would otherwise renew the same token.
*/
const refreshing = new Map<string, Promise<LiveSession | null>>();
/**
* Renew an OAuth session's access token and keep the new one. Null when the
* server refused the refresh token (a password change revokes it), which
* ends the session.
*/
function refreshSession(cookie: string, session: LiveSession): Promise<LiveSession | null> {
let inFlight = refreshing.get(session.id);
if (!inFlight) {
inFlight = (async () => {
const renewed = await refreshTokens(upstreamFor(session.username), session.tokens!);
if (!renewed) {
sessions.destroy(session.id);
forgetUpstreamSession(session.id);
return null;
}
sessions.updateTokens(cookie, renewed);
return sessions.resolve(cookie);
})().finally(() => refreshing.delete(session.id));
refreshing.set(session.id, inFlight);
}
return inFlight;
}
/**
* What push keeps to renew an account's subscription long after the session
* that started it. A password is good until it changes; OAuth tokens get a
* copy that renews itself, since push outlives any one access token.
*/
export function pushCredential(session: LiveSession): { get(): Promise<string> } {
if (!session.tokens) {
const authorization = session.authorization;
return { get: async () => authorization };
}
let tokens: TokenSet = session.tokens;
const base = upstreamFor(session.username);
return {
async get() {
if (needsRefresh(tokens)) tokens = (await refreshTokens(base, tokens)) ?? tokens;
return `Bearer ${tokens.access}`;
},
};
}
/**
* Scope the session cookie to the mount, not the whole host.
*
* Under a prefix the browser is talking to a hostname that other applications
* share, and a cookie at `/` would be sent to every one of them. Path scoping
* is not a security boundary -- anything on the origin can reach the cookie
* jar -- but it keeps the credential out of requests that have no business
* carrying it, and it lets two ihasmail instances live at `/mail` and
* `/mail2` on one host without signing each other out, which a shared cookie
* name at `/` would do.
*
* `/` for the root case: an empty Path is not the same thing and browsers
* would fall back to the directory of the request that set it.
*/
const cookiePath = config.basePath || "/";
function setSessionCookie(c: Context, value: string, remember: boolean) {
setCookie(c, config.cookieName, value, {
httpOnly: true,
sameSite: "Lax",
secure: isSecureRequest(c),
path: cookiePath,
...(remember ? { maxAge: config.sessionRememberTtl } : {}),
});
}
function upstreamFailure(c: Context, err: unknown) {
if (err instanceof UpstreamError) {
return c.json({ error: err.status === 401 ? "invalid_credentials" : "upstream_error", message: err.message }, err.status as 401 | 502);
}
const name = (err as Error)?.name ?? "";
if (name === "TimeoutError" || name === "AbortError") {
return c.json({ error: "upstream_timeout", message: "The mail server did not respond in time. This is not a problem with your password." }, 504);
}
console.error("[ihasmail] upstream failure:", err);
return c.json({ error: "upstream_error", message: "Could not reach the mail server. This is not a problem with your password." }, 502);
}
/**
* `basePath` is a parameter rather than read straight from the config so the
* tests can mount the same app twice, at the root and under a prefix, without
* re-importing the module to change one environment variable.
*/
export function createApp(basePath = config.basePath): Hono<Env> {
const app = new Hono<Env>();
app.use("*", securityHeaders);
app.use("*", compressResponses(basePath));
const api = new Hono<Env>();
api.use("*", csrfGuard);
api.use("*", smallBodies);
api.get("/health", (c) => c.json({ ok: true, name: config.appName, version: config.version, push: pushStatus() }));
/*
* Stalwart's push delivery. Authenticated by the token in the path -- 32
* random bytes, one per account, known only to us and to Stalwart -- and by
* nothing else, since Stalwart carries no credential when it POSTs. An
* unknown token is a 404 that looks like any other. See push.ts.
*/
app.post(`${basePath}/api/push/:token`, async (c) => {
if (!(c.req.header("content-type") ?? "").toLowerCase().startsWith("application/json")) return c.body(null, 415);
const len = Number(c.req.header("content-length") ?? "0");
if (!len || len > 64 * 1024) return c.body(null, 413);
let body: unknown;
try { body = await c.req.json(); } catch { return c.body(null, 400); }
return c.body(null, (await pushReceive(c.req.param("token"), body)) as 200 | 400 | 404 | 500);
});
api.get("/config", (c) =>
c.json({
appName: config.appName,
sourceUrl: config.sourceUrl,
imageProxy: config.imageProxy,
maxUploadBytes: config.maxUploadBytes,
/* Sent before sign-in like the rest of this: it says what the
installation has decided, not anything about who is asking. */
settingsPolicy: config.settingsPolicy,
/* "oauth": sign in on the mail server's own page (see oauth.ts). */
signIn: oauthEnabled() ? "oauth" : "password",
/* With "oauth": true when the server's page can take it from here, so
the sign-in form doesn't ask for an address first. */
signInDirect: oauthEnabled() && singleServer(),
}),
);
// ---------- Auth ----------
/*
* Sign-in through the mail server's page. `start` sends the browser there;
* `callback` is where the server sends it back. See oauth.ts.
*/
const OAUTH_STATE_COOKIE = `${config.cookieName}_signin`;
api.get("/auth/oauth/start", async (c) => {
if (!oauthEnabled()) return c.json({ error: "not_found" }, 404);
const rateIp = rateLimitKey(clientIp(c));
if (!loginFloodLimiter.check(rateIp)) {
c.header("Retry-After", String(loginFloodLimiter.retryAfterSeconds(rateIp)));
return c.redirect(`${basePath}/?signin_error=rate_limited`, 302);
}
const username = (c.req.query("username") ?? "").trim().slice(0, 320);
try {
const { location, state } = await startSignIn({ username, base: upstreamFor(username), remember: c.req.query("remember") === "1" });
setCookie(c, OAUTH_STATE_COOKIE, state, { httpOnly: true, sameSite: "Lax", secure: isSecureRequest(c), path: `${basePath}/api/auth`, maxAge: 600 });
return c.redirect(location, 302);
} catch (err) {
console.warn("[ihasmail] could not start sign-in:", (err as Error).message);
return c.redirect(`${basePath}/?signin_error=unavailable`, 302);
}
});
api.get("/auth/callback", async (c) => {
if (!oauthEnabled()) return c.json({ error: "not_found" }, 404);
const boundState = getCookie(c, OAUTH_STATE_COOKIE);
deleteCookie(c, OAUTH_STATE_COOKIE, { path: `${basePath}/api/auth` });
const fail = (code: string) => c.redirect(`${basePath}/?signin_error=${code}`, 302);
const rateIp = rateLimitKey(clientIp(c));
if (!loginFloodLimiter.check(rateIp)) return fail("rate_limited");
const state = c.req.query("state") ?? "";
const code = c.req.query("code") ?? "";
// The server's page sends `error` when the person cancels or is refused.
if (!code || c.req.query("error")) return fail("cancelled");
let result;
try {
result = await finishSignIn({ state, boundState, code });
} catch (err) {
if (err instanceof SignInError) return fail(err.code);
console.warn("[ihasmail] sign-in exchange failed:", (err as Error).message);
return fail("unavailable");
}
const authorization = `Bearer ${result.tokens.access}`;
try {
const upstream = await fetchUpstreamSession(authorization, result.base);
if (!hasStalwartRegistry(upstream)) return fail("unsupported_server");
const username = upstream.username || result.username;
// Every later call finds the account's server from its name. If the
// server signed in an account that routes elsewhere, calls would go to
// the wrong server, so refuse it.
if (upstreamFor(username) !== result.base) return fail("wrong_account");
const { cookie, session } = sessions.create({
username,
account: accountKey(result.base, username),
tokens: result.tokens,
remember: result.remember,
userAgent: c.req.header("user-agent") ?? "",
ip: clientIp(c),
});
setSessionCookie(c, cookie, session.remember);
const mailAccount = upstream.primaryAccounts?.["urn:ietf:params:jmap:mail"];
if (mailAccount) pushPrepare(session.username, mailAccount, pushCredential(session));
return c.redirect(`${basePath}/`, 302);
} catch (err) {
console.warn("[ihasmail] sign-in failed after the exchange:", (err as Error).message);
return fail("unavailable");
}
});
api.post("/auth/login", async (c) => {
// With sign-in on the mail server's page, this form never sees a password.
if (oauthEnabled()) return c.json({ error: "oauth_required", message: "Sign in on the mail server's page." }, 403);
const ip = clientIp(c);
// What the limits count under: the address, or its /64 for IPv6.
const rateIp = rateLimitKey(ip);
// The flood ceiling needs nothing from the body, so it goes before reading one.
if (!loginFloodLimiter.check(rateIp)) {
c.header("Retry-After", String(loginFloodLimiter.retryAfterSeconds(rateIp)));
return c.json({ error: "rate_limited", message: "Too many login attempts. Please wait and try again." }, 429);
}
let body: { username?: string; password?: string; totp?: string; remember?: boolean };
try {
body = await c.req.json();
} catch {
return c.json({ error: "bad_request" }, 400);
}
const username = (body.username ?? "").trim();
const password = body.password ?? "";
const totp = (body.totp ?? "").trim();
if (!username || !password) return c.json({ error: "missing_credentials" }, 400);
if (username.length > 320 || password.length > 1024) return c.json({ error: "bad_request" }, 400);
/*
* Three checks, answering different questions.
*
* `limitKey` is this username from this address, and `rateIp` is any username
* from it -- both guard guessing, and both are given back when the upstream
* never got as far as judging the password. Refunding only the first would
* not fix #239: ten retries through an outage would still spend the address
* budget, and behind one office NAT that budget belongs to the whole
* building.
*
* The flood ceiling is the one that is never refunded, and it is the reason
* the other two safely can be.
*/
const limitKey = `${rateIp}|${username.toLowerCase()}`;
if (!loginLimiter.check(limitKey) || !loginLimiter.check(rateIp)) {
c.header("Retry-After", String(loginLimiter.retryAfterSeconds(limitKey)));
return c.json({ error: "rate_limited", message: "Too many login attempts. Please wait and try again." }, 429);
}
// Stalwart accepts TOTP codes appended to the password as "password$123456".
const effectivePassword = totp ? `${password}$${totp}` : password;
const authorization = `Basic ${Buffer.from(`${username}:${effectivePassword}`, "utf8").toString("base64")}`;
try {
const upstream = await fetchUpstreamSession(authorization, upstreamFor(username));
// ihasmail requires Stalwart 0.16 or newer. Refuse here, once and
// clearly, rather than signing someone in and letting Files, the account
// locale and self-service credentials each fail in their own way with
// nothing to connect them. The credentials were good, so say so.
if (!hasStalwartRegistry(upstream)) {
// The credentials were accepted; only the server is too old. Not an
// attempt worth counting against them.
loginLimiter.refund(limitKey);
loginLimiter.refund(rateIp);
return c.json(
{
error: "unsupported_server",
message:
"Your credentials are fine, but this mail server is older than Stalwart 0.16, which ihasmail needs. Upgrade the server, or run the release tagged stalwart-0.15-support.",
},
501,
);
}
loginLimiter.reset(limitKey);
const { cookie, session } = sessions.create({
username,
account: accountKey(upstreamFor(username), upstream.username || username),
password: effectivePassword,
remember: Boolean(body.remember),
userAgent: c.req.header("user-agent") ?? "",
ip,
});
setSessionCookie(c, cookie, session.remember);
// Start the account's push subscription now, so it is usually verified
// by the time the browser opens its stream. See push.ts.
const mailAccount = upstream.primaryAccounts?.["urn:ietf:params:jmap:mail"];
if (mailAccount) pushPrepare(session.username, mailAccount, pushCredential(session));
const info = await getAccountInfo(session.id, session.authorization, upstream);
return c.json(localizeSession(upstream, sessionExtras(session, info)));
} catch (err) {
// A rejected sign-in that carried a two-factor code is worth explaining
// rather than calling "invalid credentials", because the credentials are
// very likely fine.
//
// Stalwart accepts a TOTP code only through an OAuth flow -- its own web
// interface is an OAuth client, which is why signing in there works. It
// offers no password grant, so a client holding a username and password
// cannot exchange them plus a code for a token, and the concatenated
// `password$code` form ihasmail sent is not a route the server has. Its
// documented answer for clients like this one is an app password, which
// bypasses TOTP entirely.
//
// ihasmail already relies on that elsewhere: turning 2FA *on* mints an
// app password and moves the session onto it, precisely because a plain
// password stops working from that moment. The sign-in page was the one
// place still pretending otherwise.
if (totp && err instanceof UpstreamError && err.status === 401) {
return c.json(
{
error: "totp_unsupported",
message:
"This mail server does not accept two-factor codes from webmail. Sign in with an app password instead — create one in Stalwart's own settings, under app passwords. Your password and code are probably fine.",
},
401,
);
}
/*
* A 401 is a judgment about the password and stays counted. Anything
* else -- refused, timed out, DNS, TLS -- is the upstream failing to
* answer, which says nothing about the credentials and must not spend
* somebody's attempts while they wait for it to come back (#239).
*/
if (!(err instanceof UpstreamError && err.status === 401)) {
loginLimiter.refund(limitKey);
loginLimiter.refund(rateIp);
}
return upstreamFailure(c, err);
}
});
api.get("/auth/session", requireSession, async (c) => {
const session = c.get("session");
try {
const upstream = await getUpstreamSession(session.id, session.authorization, upstreamFor(session.username), c.req.query("refresh") === "1");
const info = await getAccountInfo(session.id, session.authorization, upstream);
return c.json(localizeSession(upstream, sessionExtras(session, info)));
} catch (err) {
if (err instanceof UpstreamError && err.status === 401) {
sessions.destroy(session.id);
deleteCookie(c, config.cookieName, { path: cookiePath });
}
return upstreamFailure(c, err);
}
});
api.post("/auth/logout", async (c) => {
const cookie = getCookie(c, config.cookieName);
const session = sessions.resolve(cookie);
if (session) {
sessions.destroy(session.id);
forgetUpstreamSession(session.id);
}
deleteCookie(c, config.cookieName, { path: cookiePath });
return c.json({ ok: true });
});
api.get("/auth/sessions", requireSession, (c) => {
const session = c.get("session");
return c.json({ current: session.id, sessions: sessions.listForUser(session.account) });
});
api.post("/auth/sessions/revoke-others", requireSession, (c) => {
const session = c.get("session");
const n = sessions.destroyAllForUser(session.account, session.id);
return c.json({ revoked: n });
});
// ---------- Self-service credentials ----------
/**
* Password, app passwords and 2FA. These live on the server rather than in
* the browser because changing a credential means re-sealing the session
* cookie that holds it, and because the browser only ever sees /api/jmap.
*/
const accountCtx = async (c: Context<Env>) => {
const session = c.get("session");
// The account's own server. Without it, the first fetch after the cached
// session expires goes to STALWART_URL -- which, for a domain mapped
// elsewhere, either refuses the password or knows a different account by
// the same name (#238).
const upstream = await getUpstreamSession(session.id, session.authorization, upstreamFor(session.username));
return { authorization: session.authorization, session: upstream, username: session.username };
};
const accountFailure = (c: Context, err: unknown) => {
if (err instanceof AccountError) {
return c.json({ error: err.code, message: err.message }, err.status as 400);
}
return upstreamFailure(c, err);
};
/** Guard the endpoints that check a password against brute-forcing. */
const guarded = (c: Context<Env>, scope = "account"): Response | null => {
const key = `${scope}|${c.get("session").username.toLowerCase()}`;
if (accountLimiter.check(key)) return null;
c.header("Retry-After", String(accountLimiter.retryAfterSeconds(key)));
return c.json({ error: "rate_limited", message: "Too many attempts. Please wait and try again." }, 429);
};
api.get("/account/security", requireSession, async (c) => {
const session = c.get("session");
try {
return c.json(await getState(await accountCtx(c)));
} catch (err) {
return accountFailure(c, err);
}
});
api.post("/account/password", requireSession, async (c) => {
const limited = guarded(c);
if (limited) return limited;
const session = c.get("session");
const body = await readJson<{ current?: string; next?: string; otpCode?: string }>(c);
if (!body) return c.json({ error: "bad_request" }, 400);
const current = body.current ?? "";
const next = body.next ?? "";
if (!current || !next) return c.json({ error: "missing_fields", message: "Both passwords are required." }, 400);
if (next.length > 1024) return c.json({ error: "bad_request" }, 400);
if (next === current) {
return c.json({ error: "unchanged", message: "The new password matches the old one." }, 400);
}
try {
await changePassword(await accountCtx(c), { current, next, otpCode: body.otpCode?.trim() || undefined });
} catch (err) {
return accountFailure(c, err);
}
if (session.tokens) {
// The server revokes every token when the password changes, this
// session's included, so there is nothing to keep: sign in again.
forgetUpstreamSession(session.id);
const revoked = sessions.destroyAllForUser(session.account);
deleteCookie(c, config.cookieName, { path: cookiePath });
return c.json({ ok: true, revokedSessions: revoked - 1, signedOut: true });
}
// The old password is now dead: re-seal this session with the new one and
// drop the others, whose sealed copies would fail on their next call.
const otpCode = body.otpCode?.trim();
sessions.reseal(getCookie(c, config.cookieName), otpCode ? `${next}$${otpCode}` : next);
forgetUpstreamSession(session.id);
const revoked = sessions.destroyAllForUser(session.account, session.id);
return c.json({ ok: true, revokedSessions: revoked });
});
api.get("/account/app-passwords", requireSession, async (c) => {
const session = c.get("session");
try {
const state = await getState(await accountCtx(c));
return c.json({ appPasswords: state.appPasswords });
} catch (err) {
return accountFailure(c, err);
}
});
/*
* An app password is a credential that outlives this session, a password
* change and a sign-out -- so minting one asks for the account password, as
* changing the password does. Otherwise a session left open on somebody
* else's machine is enough to take a permanent key away from it.
*/
api.post("/account/app-passwords", requireSession, async (c) => {
// A budget of its own: guessing here never reaches Stalwart (see confirmsPassword).
const limited = guarded(c, "app-password");
if (limited) return limited;
const session = c.get("session");
const body = await readJson<{ description?: string; current?: string }>(c);
if (!body) return c.json({ error: "bad_request" }, 400);
const description = (body.description ?? "").trim().slice(0, 120);
if (!description) return c.json({ error: "missing_fields", message: "Give the app password a name." }, 400);
const current = body.current ?? "";
if (!current || current.length > 1024) return c.json({ error: "missing_fields", message: "Enter your current password." }, 400);
if (!(await confirmsPassword(session, current))) {
return c.json({ error: "invalid_credentials", message: "That password is not correct." }, 403);
}
try {
return c.json(await createAppPassword(await accountCtx(c), { description }));
} catch (err) {
return accountFailure(c, err);
}
});
api.post("/account/app-passwords/revoke", requireSession, async (c) => {
const session = c.get("session");
const body = await readJson<{ id?: string }>(c);
if (!body?.id) return c.json({ error: "bad_request" }, 400);
try {
await revokeAppPassword(await accountCtx(c), body.id);
return c.json({ ok: true });
} catch (err) {
return accountFailure(c, err);
}
});
api.post("/account/2fa/begin", requireSession, async (c) => {
try {
// Nothing is stored yet; the client hands the URL back to confirm.
return c.json(beginOtpEnrollment(await accountCtx(c)));
} catch (err) {
return accountFailure(c, err);
}
});
api.post("/account/2fa/enable", requireSession, async (c) => {
const limited = guarded(c);
if (limited) return limited;
const session = c.get("session");
const body = await readJson<{ url?: string; code?: string; current?: string }>(c);
if (!body?.url || !body.code || !body.current) return c.json({ error: "bad_request" }, 400);
const ctx = await accountCtx(c);
const code = body.code.trim();
/*
* Every proxied call re-authenticates with the stored password, and once
* 2FA is on the server wants a fresh TOTP code alongside it — which we
* cannot produce between requests. An app password authenticates without
* one, so the session moves onto a dedicated app password rather than
* being signed out the moment 2FA is switched on.
*
* Order matters: mint it while the current credential still works, since
* the moment 2FA is enabled this session can no longer authenticate at all.
*/
try {
assertEnrollmentCode(body.url, code);
} catch (err) {
return accountFailure(c, err);
}
if (session.tokens) {
// Signed in on the server's page, where two-factor is asked for, so
// nothing here needs moving onto an app password.
try {
await enableOtp(ctx, { url: body.url, code, current: body.current });
} catch (err) {
return accountFailure(c, err);
}
return c.json({ ok: true, ...(await afterCredentialChange(c, session)) });
}
let app: { id: string; secret: string } | null = null;
try {
app = await createAppPassword(ctx, { description: appPasswordName(c) });
} catch (err) {
// Out of app-password quota, say. 2FA is still worth having; the user
// just has to sign in again afterwards.
console.warn("[ihasmail] could not mint a session app password:", (err as Error).message);
}
try {
await enableOtp(ctx, { url: body.url, code, current: body.current });
} catch (err) {
if (app) {
// Don't leave a credential behind for a change that never happened.
await revokeAppPassword(ctx, app.id).catch(() => {});
}
return accountFailure(c, err);
}
let sessionKept = false;
if (app) {
sessionKept = sessions.reseal(getCookie(c, config.cookieName), app.secret);
if (sessionKept) forgetUpstreamSession(session.id);
}
// Other sessions still hold the bare password and will be refused.
const revoked = sessions.destroyAllForUser(session.account, session.id);
return c.json({ ok: true, sessionKept, revokedSessions: revoked });
});
api.post("/account/2fa/disable", requireSession, async (c) => {
const limited = guarded(c);
if (limited) return limited;
const session = c.get("session");
const body = await readJson<{ current?: string; code?: string }>(c);
if (!body?.current || !body.code) return c.json({ error: "bad_request" }, 400);
try {
await disableOtp(await accountCtx(c), { current: body.current, code: body.code.trim() });
} catch (err) {
return accountFailure(c, err);
}
if (session.tokens) return c.json({ ok: true, ...(await afterCredentialChange(c, session)) });
// This session may be running on the app password minted when 2FA went on;
// the plain password works again now, so put it back.
sessions.reseal(getCookie(c, config.cookieName), body.current);
forgetUpstreamSession(session.id);
return c.json({ ok: true });
});
// ---------- JMAP API proxy ----------
api.post("/jmap", requireSession, apiRateLimited, async (c) => {
const session = c.get("session");
const ct = c.req.header("content-type") ?? "";
if (!ct.toLowerCase().startsWith("application/json")) {
return c.json({ error: "unsupported_media_type" }, 415);
}
/*
* For a session that may not administer -- administration switched off, or
* a device not marked as the person's own -- the body is read and checked
* before it goes anywhere. A session that may streams straight through as
* it always has, and pays nothing for this.
*/
let body: ReadableStream<Uint8Array> | string | null = c.req.raw.body;
if (!administrationAllowed(config.administration, session.remember)) {
const held = gatedReads.get(session.id) ?? 0;
if (held >= MAX_GATED_PER_SESSION) {
c.header("Retry-After", "1");
return c.json({ error: "rate_limited" }, 429);
}
gatedReads.set(session.id, held + 1);
let raw: string;
try {
if (Number(c.req.header("content-length") ?? "0") > MAX_GATED_REQUEST) return c.json({ error: "too_large" }, 413);
// Counted as it arrives: a chunked body carries no length to refuse up front.
raw = c.req.raw.body ? await readGated(c.req.raw.body) : "";
} catch (err) {
if (err instanceof GatedBudgetError) {
c.header("Retry-After", "1");
return c.json({ error: "busy" }, 503);
}
return c.json({ error: "too_large" }, 413);
} finally {
const left = (gatedReads.get(session.id) ?? 1) - 1;
if (left > 0) gatedReads.set(session.id, left);
else gatedReads.delete(session.id);
}
const gate = gateAdministration(raw);
if (!gate.ok) {
if (!gate.method) return c.json({ error: "bad_request", message: "Not a JMAP request." }, 400);
return config.administration
? c.json({ error: "administration_needs_own_device", message: `Administration is only available when signed in on a device marked as your own (${gate.method}).` }, 403)
: c.json({ error: "administration_disabled", message: `Administration is turned off on this installation (${gate.method}).` }, 403);
}
body = gate.body;
}
try {
const upstream = await getUpstreamSession(session.id, session.authorization, upstreamFor(session.username));
const res = await fetch(absoluteUpstream(upstream.apiUrl, upstream.baseUrl), {
method: "POST",
headers: {
authorization: session.authorization,
"content-type": "application/json",
accept: "application/json",
},
body,
duplex: "half",
signal: AbortSignal.timeout(config.upstreamTimeout),
});
if (res.status === 401) {
sessions.destroy(session.id);
forgetUpstreamSession(session.id);
deleteCookie(c, config.cookieName, { path: cookiePath });
return c.json({ error: "unauthenticated" }, 401);
}
return passthrough(res);
} catch (err) {
return upstreamFailure(c, err);
}
});
// ---------- Administration: Stalwart's permission list ----------
/*
* The one administration read that is not a JMAP call: the labeled list of
* permissions from Stalwart's schema, for the Roles picker. Behind the same
* two gates as the registry methods, so a session that may not administer
* learns nothing from it.
*/
api.get("/admin/permissions", requireSession, apiRateLimited, async (c) => {
const session = c.get("session");
if (!administrationAllowed(config.administration, session.remember)) {
return config.administration
? c.json({ error: "administration_needs_own_device" }, 403)
: c.json({ error: "administration_disabled" }, 403);
}
try {
const upstream = await getUpstreamSession(session.id, session.authorization, upstreamFor(session.username));
const permissions = await fetchPermissions(session.authorization, upstream.baseUrl);
if (!permissions) return c.json({ error: "upstream_error" }, 502);
return c.json({ permissions });
} catch (err) {
return upstreamFailure(c, err);
}
});
// ---------- Blob upload ----------
api.post("/upload/:accountId", requireSession, async (c) => {
const session = c.get("session");
const accountId = c.req.param("accountId");
const len = Number(c.req.header("content-length") ?? "0");
if (len > config.maxUploadBytes) return c.json({ error: "too_large" }, 413);
// content-length is absent on a chunked request, so the header alone is a
// suggestion; count the bytes as they go past.
const body = c.req.raw.body ? c.req.raw.body.pipeThrough(byteCap(config.maxUploadBytes)) : null;
try {
const upstream = await getUpstreamSession(session.id, session.authorization, upstreamFor(session.username));
const url = absoluteUpstream(expandTemplate(upstream.uploadUrl, { accountId }), upstream.baseUrl);
const res = await fetch(url, {
method: "POST",
headers: {
authorization: session.authorization,
"content-type": c.req.header("content-type") ?? "application/octet-stream",
accept: "application/json",
},
body,
duplex: "half",
signal: AbortSignal.timeout(Math.max(config.upstreamTimeout, 5 * 60_000)),
});
return passthrough(res);
} catch (err) {
return upstreamFailure(c, err);
}
});
// ---------- Blob download ----------
api.get("/blob/:accountId/:blobId/:name", requireSession, apiRateLimited, async (c) => {
const session = c.get("session");
const { accountId, blobId, name } = c.req.param();
const accept = c.req.query("accept") ?? "application/octet-stream";
const inline = c.req.query("inline") === "1";
try {
const upstream = await getUpstreamSession(session.id, session.authorization, upstreamFor(session.username));
const url = absoluteUpstream(expandTemplate(upstream.downloadUrl, { accountId, blobId, name, type: accept }), upstream.baseUrl);
// A PDF viewer or a video element asks for pieces; pass that on. A server
// that ignores it answers with the whole file, as it did before.
const range = c.req.header("range");
const res = await fetch(url, {
// Ask for the bytes as they are. undici would otherwise negotiate gzip
// on our behalf and hand back a decompressed body whose content-length
// header still describes the compressed one -- see forwardedContentLength.
headers: { authorization: session.authorization, "accept-encoding": "identity", ...(range && /^bytes=[\d,\s-]+$/.test(range) ? { range } : {}) },
signal: AbortSignal.timeout(Math.max(config.upstreamTimeout, 5 * 60_000)),
});
if (res.status === 416) return c.body(null, 416);
if (!res.ok) return c.json({ error: "not_found" }, res.status === 404 ? 404 : 502);
const headers = new Headers();
const type = sanitizeContentType(res.headers.get("content-type") ?? accept);
headers.set("Content-Type", type);
const cl = forwardedContentLength(res.headers);
if (cl) headers.set("Content-Length", cl);
const partial = res.status === 206 && res.headers.get("content-range");
if (partial) headers.set("Content-Range", partial);
/*
* Said here because Stalwart does not say it. It honors a single byte
* range but sends no `Accept-Ranges` (0.16.22, checked live on
* 2026-09-16), and Chrome's PDF viewer only reads a file in pieces when
* the first response advertises it. A server that ignores a range sends
* the whole file, which the browser takes just as well.
*/
headers.set("Accept-Ranges", "bytes");
const safeInline = inline && isInlineSafe(type);
headers.set(
"Content-Disposition",
`${safeInline ? "inline" : "attachment"}; filename*=UTF-8''${encodeURIComponent(withoutBidiControls(name))}`,
);
headers.set("X-Content-Type-Options", "nosniff");
// Sandbox everything except the browser's built-in PDF viewer (which needs scripts to render).
if (securityHeadersFor(type, safeInline) === "SAMEORIGIN") {
/*
* The one response on the server that may be framed.
*
* A PDF is shown in an iframe -- it is its own document and the app
* cannot lay it out -- and the blanket X-Frame-Options: DENY above
* blocked that, so the preview showed Chrome's "refused to connect"
* instead of the file. SAMEORIGIN, not a relaxation to any site: the
* frame is ours, on our origin, and the app's own CSP already says
* frame-src 'self'. Nothing else here is framed, so nothing else asks.
*/
headers.set("X-Frame-Options", "SAMEORIGIN");
} else {
headers.set("Content-Security-Policy", "sandbox; default-src 'none'; style-src 'unsafe-inline'; img-src data:");
}
// Kept out of the browser's disk cache on a device that is not the
// person's own: signing out wipes what the app stores, not that.
/*
* A blob id names its content -- the same id is the same bytes for good
* -- so on the reader's own device there is nothing to revalidate. On
* anyone else's, nothing is left in the disk cache at all.
*/
headers.set("Cache-Control", session.remember ? "private, max-age=31536000, immutable" : "no-store");
return new Response(res.body, { status: partial ? 206 : 200, headers });
} catch (err) {
return upstreamFailure(c, err);
}
});
// ---------- Push (Server-Sent Events) ----------
api.get("/events", requireSession, async (c) => {
const session = c.get("session");
const types = c.req.query("types") ?? "*";
const closeafter = c.req.query("closeafter") ?? "no";
const ping = c.req.query("ping") ?? "30";
try {
const upstream = await getUpstreamSession(session.id, session.authorization, upstreamFor(session.username));
const url = absoluteUpstream(expandTemplate(upstream.eventSourceUrl, { types, closeafter, ping }), upstream.baseUrl);
// Subscribe mode: if this account's subscription is verified, the tab is
// served by fan-out and holds nothing upstream. Otherwise it gets its own
// relay, and is moved to fan-out the moment the account verifies.
const accountId = upstream.primaryAccounts?.["urn:ietf:params:jmap:mail"];
const out = (c.env as { outgoing: import("node:http").ServerResponse }).outgoing;
if (accountId && pushAttach(session.username, accountId, pushCredential(session), out)) {
out.writeHead(200, SSE_HEADERS);
out.flushHeaders();
out.write(": subscribed\n\n");
return RESPONSE_ALREADY_SENT;
}
if (config.rawPushRelay) return relayPushRaw(c, url, session.authorization, session.username);
const controller = new AbortController();
c.req.raw.signal.addEventListener("abort", () => controller.abort());
const res = await fetch(url, {
headers: { authorization: session.authorization, accept: "text/event-stream" },
signal: controller.signal,
});
if (!res.ok || !res.body) return c.json({ error: "upstream_error" }, 502);
const headers = new Headers({
"Content-Type": "text/event-stream",
"Cache-Control": "no-cache, no-transform",
Connection: "keep-alive",
"X-Accel-Buffering": "no",
});
return new Response(res.body, { status: 200, headers });
} catch (err) {
return upstreamFailure(c, err);
}
});
// ---------- Remote image privacy proxy ----------
api.get("/image", requireSession, apiRateLimited, imageProxyHandler);
// Behind the session for the same reason the image proxy is: an open fetcher
// on someone else's server is a gift to whoever finds it.
api.get("/ics", requireSession, apiRateLimited, icsProxyHandler);
api.notFound((c) => c.json({ error: "not_found" }, 404));
api.onError((err, c) => {
console.error("[ihasmail] api error:", err);
return c.json({ error: "internal_error" }, 500);
});
app.route(`${basePath}/api`, api);
// ---------- Static SPA ----------
app.get("*", staticHandler(config.staticDir, basePath));
return app;
}
/** Fail a stream that runs past `max` bytes, whatever its headers claimed. */
function byteCap(max: number): TransformStream<Uint8Array, Uint8Array> {
let total = 0;
return new TransformStream<Uint8Array, Uint8Array>({
transform(chunk, controller) {
total += chunk.byteLength;
if (total > max) controller.error(new Error("upload too large"));
else controller.enqueue(chunk);
},
});
}
async function readJson<T>(c: Context): Promise<T | null> {
try {
return (await c.req.json()) as T;
} catch {
return null;
}
}
/**
* Is `candidate` the password of the account this session is signed in to?
*
* Compared with the credential the session holds first, which costs nothing
* and tells Stalwart nothing -- its auto-ban counts failures against the
* proxy's address, which every user shares. That credential is the password,
* with a TOTP code after a `$` when one was given at sign-in. A session that
* turning on 2FA moved onto an app password (Stalwart's secrets start
* `$app$`) holds something else, and only then is the candidate put to the
* server.
*/
async function confirmsPassword(session: LiveSession, candidate: string): Promise<boolean> {
if (session.tokens) {
// Holding no password, the only judge is the server.
try {
const authorization = `Basic ${Buffer.from(`${session.username}:${candidate}`, "utf8").toString("base64")}`;
await fetchUpstreamSession(authorization, upstreamFor(session.username));
return true;
} catch {
return false;
}
}
const decoded = Buffer.from(session.authorization.replace(/^Basic /, ""), "base64").toString("utf8");
const held = decoded.slice(decoded.indexOf(":") + 1);
if (safeEqual(held, candidate)) return true;
const withoutCode = held.replace(/\$\d{6,8}$/, "");
if (withoutCode !== held && safeEqual(withoutCode, candidate)) return true;
// Holding the password, the comparison above is the answer, and a wrong
// guess never reaches the server's auto-ban.
if (!held.startsWith("$app$")) return false;
try {
const authorization = `Basic ${Buffer.from(`${session.username}:${candidate}`, "utf8").toString("base64")}`;
await fetchUpstreamSession(authorization, upstreamFor(session.username));
return true;
} catch {
return false;
}
}
/**
* After a two-factor change on a token session: whether the server still
* honors this session's token. If it revoked it, end the session here too,
* so the web app can send the person to sign in again.
*/
async function afterCredentialChange(c: Context<Env>, session: LiveSession): Promise<{ signedOut: boolean }> {
forgetUpstreamSession(session.id);
try {
await fetchUpstreamSession(session.authorization, upstreamFor(session.username));
return { signedOut: false };
} catch (err) {
if (!(err instanceof UpstreamError && err.status === 401)) return { signedOut: false };
sessions.destroyAllForUser(session.account);
deleteCookie(c, config.cookieName, { path: cookiePath });
return { signedOut: true };
}
}
/**
* Direction overrides and isolates, which can make `Invoice_\u202Efdp.exe`
* read as a PDF in the downloads list. A filename has no use for them.
*/
function withoutBidiControls(name: string): string {
return name.replace(/[\u061C\u200E\u200F\u202A-\u202E\u2066-\u2069]/g, "");
}
/** Name the app password after the browser it will live in. */
function appPasswordName(c: Context): string {
const ua = c.req.header("user-agent") ?? "";
const browser = /Firefox\//.test(ua) ? "Firefox" : /Edg\//.test(ua) ? "Edge" : /Chrome\//.test(ua) ? "Chrome" : /Safari\//.test(ua) ? "Safari" : "browser";
return `${config.appName} (${browser})`;
}
function sessionExtras(session: LiveSession, info: AccountInfo = { locale: null, edition: null, permissions: [] }) {
return {
ihasmail: {
appName: config.appName,
sourceUrl: config.sourceUrl,
imageProxy: config.imageProxy,
maxUploadBytes: config.maxUploadBytes,
sessionId: session.id,
loginName: session.username,
remember: session.remember,
/** "oauth": signed in on the mail server's page, holding tokens, not a password. */
signIn: session.tokens ? "oauth" : "password",
/** Locale configured for the account in Stalwart's directory, if readable. */
userLocale: info.locale,
/**
* What the upstream server would tell us about itself, and -- for a
* session that may administer -- where the operator says its own
* administration is.
*/
server: {
edition: info.edition,
adminUrl: administrationAllowed(config.administration, session.remember) ? adminUrlFor(session.username, info.adminUrl ?? null) : null,
/** SHOW_ENTERPRISE_NOTICES: say "Enterprise feature" on Enterprise too, as the demo does. */
enterpriseNotices: config.showEnterpriseNotices,
},
/**
* Whether this session may administer: the installation offers it
* (ADMINISTRATION) and the person signed in on a device marked as their own.
*/
administration: administrationAllowed(config.administration, session.remember),
/**
* An administrator signed in on a device not marked as their own, so the
* menu can say why Administration is unavailable rather than lose it
* without a word. Says only that the account administers, never what it
* may do.
*/
administrationNeedsOwnDevice: config.administration && !session.remember && grantsAdministration(info.permissions),
/**
* The account's permissions on that server, so the client can offer
* administration to those who have it. Stalwart still decides every call.
* Withheld from a session that may not administer: nothing in it needs them.
*/
permissions: administrationAllowed(config.administration, session.remember) ? info.permissions : [],
},
};
}
/**
* Headers worth relaying from the mail server. An allowlist rather than a
* denylist: everything else it might set — cookies, auth challenges, CORS
* grants — would be landing on *our* origin, where it means something else.
*/
/**
* The largest JMAP request read into memory for the administration check.
*
* Only sessions that may not administer come this way, and what the client
* sends is small: attachments and pasted images go through `/upload`, and the
* composer turns inline images into uploads before a draft is saved. Stalwart
* would take up to its `maxSizeRequest` (10 MB by default), but a request is
* held here as a string, parsed and serialized again, so each one costs
* several times its size; 4 MB is far past anything the client sends.
*/
const MAX_GATED_REQUEST = 4 * 1024 * 1024;
/**
* How many checked requests one session may have in flight at once. Matches
* the `maxConcurrentRequests` Stalwart advertises by default, which the client
* already stays within.
*/
const MAX_GATED_PER_SESSION = 4;
/**
* The bytes all checked requests together may hold at once. Counted as they
* arrive rather than reserved up front, so a slow body that has sent little
* holds little, and a burst of large ones is turned away with a 503 instead of
* taking the process down.
*/
const GATED_BUDGET = 32 * 1024 * 1024;
const gatedReads = new Map<string, number>();
let gatedBytes = 0;
class GatedBudgetError extends Error {}
async function readGated(stream: ReadableStream<Uint8Array>): Promise<string> {
let mine = 0;
const counted = new TransformStream<Uint8Array, Uint8Array>({
transform(chunk, controller) {
mine += chunk.byteLength;
gatedBytes += chunk.byteLength;
if (mine > MAX_GATED_REQUEST) controller.error(new Error("request too large"));
else if (gatedBytes > GATED_BUDGET) controller.error(new GatedBudgetError("gated read budget spent"));
else controller.enqueue(chunk);
},
});
try {
return await new Response(stream.pipeThrough(counted)).text();
} finally {
gatedBytes -= mine;
}
}
const PASSTHROUGH_HEADERS = new Set(["content-type", "content-disposition", "content-language", "etag", "last-modified", "retry-after"]);
/**
* Hold a push stream open with the least machinery that will do it.
*
* The fetch() version above builds an undici Response, a web ReadableStream,
* a reader, and Hono's stream-to-Node bridge for every tab, and keeps all of
* it alive for as long as the tab is open. Measured against a real Stalwart
* that is about 44 KiB of JavaScript heap per tab -- twelve times what the
* session itself costs -- and a signed-in tab is otherwise nothing but this
* one held connection. Here the upstream socket is piped straight into the
* Node response, so what stays resident per tab is two sockets and their
* small IncomingMessage/ServerResponse pair.
*
* Returns a Response Hono treats as already sent: the raw bindings are
* written to directly, and the returned value is never serialized.
*/
const SSE_HEADERS = {
"content-type": "text/event-stream",
"cache-control": "no-cache, no-transform",
connection: "keep-alive",
"x-accel-buffering": "no",
} as const;
function relayPushRaw(c: Context<Env>, url: string, authorization: string, username?: string): Response {
const out = (c.env as { outgoing: import("node:http").ServerResponse }).outgoing;
const target = new URL(url);
const req = (target.protocol === "https:" ? httpsRequest : httpRequest)(target, {
method: "GET",
headers: { authorization, accept: "text/event-stream" },
});
const signal = c.req.raw.signal;
const abort = () => req.destroy();
signal.addEventListener("abort", abort);
out.on("close", abort);
const fail = () => {
if (!out.headersSent) {
out.writeHead(502, { "content-type": "application/json", "cache-control": "no-store" });
out.end(JSON.stringify({ error: "upstream_error" }));
} else {
out.end();
}
};
/*
* Once this account's subscription verifies, the upstream request goes and
* the browser stream below is served by fan-out instead. Three things have
* to be true for that to be seamless: the browser must already have its
* headers (verification can beat the upstream response); nothing may treat
* the torn-down upstream as an error; and nothing may keep a reference to
* it -- the request, its response and this handler's context are exactly
* the per-tab weight the subscription exists to shed.
*/
let migrated = false;
const migrate = () => {
migrated = true;
if (!out.headersSent) { out.writeHead(200, SSE_HEADERS); out.flushHeaders(); }
signal.removeEventListener("abort", abort);
out.removeListener("close", abort);
req.removeAllListeners();
req.on("error", () => {});
req.destroy();
};
if (username) pushAttachRelay(username, out, migrate);
req.on("response", (res) => {
if (migrated) { res.destroy(); return; }
if (res.statusCode !== 200) { res.resume(); fail(); return; }
if (!out.headersSent) { out.writeHead(200, SSE_HEADERS); out.flushHeaders(); }
// end: false -- the browser stream outlives the upstream if we migrate.
res.pipe(out, { end: false });
res.on("end", () => { if (!migrated) out.end(); });
res.on("error", () => { if (!migrated) out.end(); });
});
req.on("error", () => { if (!migrated) fail(); });
req.end();
// Tells @hono/node-server the raw ServerResponse has been written to and
// must be left alone.
return RESPONSE_ALREADY_SENT;
}
function passthrough(res: Response): Response {
const headers = new Headers();
res.headers.forEach((v, k) => {
if (PASSTHROUGH_HEADERS.has(k.toLowerCase())) headers.set(k, v);
});
if (!headers.has("content-type")) headers.set("content-type", "application/json");
headers.set("Cache-Control", "no-store");
return new Response(res.body, { status: res.status, headers });
}
/**
* The upstream content-length, but only when it describes the bytes we are
* about to forward.
*
* A compressed response is decompressed for us before we ever see the body --
* undici does it transparently -- while the content-length header is left
* describing the *compressed* length. Copying it onto the longer body we then
* send makes the browser stop reading exactly that many bytes in and call the
* download complete, so the file arrives silently truncated.
*
* That is the second half of issue #76. A hop in front of Stalwart compressed
* responses over 1 KiB, so a Sieve script stayed intact until the third rule
* pushed it past the threshold and it came back cut off mid-rule. Nothing
* reported an error: the script parsed, just with rules missing, and saving
* wrote that shortened version back over the real one.
*
* We ask for `identity` above so the usual case still carries a length the
* browser can show progress against; this is the guard for a hop that
* compresses anyway.
*/
export function forwardedContentLength(headers: Headers): string | null {
const encoding = headers.get("content-encoding")?.trim().toLowerCase();
if (encoding && encoding !== "identity") return null;
return headers.get("content-length");
}
function sanitizeContentType(ct: string): string {
const lower = ct.split(";")[0]!.trim().toLowerCase();
// Never let the browser render HTML/SVG/XML/JS served from the blob endpoint.
if (
lower === "text/html" ||
lower === "application/xhtml+xml" ||
lower === "image/svg+xml" ||
lower.includes("javascript") ||
lower === "text/xml" ||
lower === "application/xml"
) {
return "application/octet-stream";
}
if (lower.startsWith("text/")) return `${lower}; charset=utf-8`;
return lower || "application/octet-stream";
}
/**
* What X-Frame-Options a blob response carries. Exported so the rule is
* testable without standing up an upstream: a PDF served inline may be framed
* by us and nothing else may be framed at all.
*/
export function securityHeadersFor(type: string, safeInline: boolean): "SAMEORIGIN" | "DENY" {
return safeInline && type.split(";")[0]!.trim() === "application/pdf" ? "SAMEORIGIN" : "DENY";
}
function isInlineSafe(type: string): boolean {
const t = type.split(";")[0]!.trim();
return (
(t.startsWith("image/") && t !== "image/svg+xml") ||
t.startsWith("video/") ||
t.startsWith("audio/") ||
t === "application/pdf" ||
t === "text/plain" ||
t === "text/calendar" ||
t === "text/vcard"
);
}