Files
openchamber/packages/web/server/lib/relay/identity.js
T
Bohdan Triapitsyn 859b4529da feat: add private relay for end-to-end-encrypted remote access (#2087)
Adds OpenChamber Relay — an opt-in way to reach an instance from a phone,
browser, or another desktop from anywhere, with no open inbound ports, no
tunnel, and no shared LAN. The instance dials outbound to a relay; all app
traffic (HTTP, the event stream, terminal, dictation) is multiplexed and
encrypted through a single connection per client, so the relay only ever
forwards opaque ciphertext.

Transport
- End-to-end-encrypted channel over WebCrypto (ECDH P-256 -> HKDF ->
  AES-256-GCM) with a capability-negotiated handshake and a small
  HTTP/SSE/WebSocket multiplexing protocol. A byte-compatible JS host mirror
  is cross-checked by tests.
- Host: outbound connection manager, per-client tunnel dispatcher to the local
  server over loopback, reuse of the existing instance identity key, and
  management routes. Disabled by default; explicit opt-in.
- Client: plugs into the existing runtime layer (runtime-fetch/-url/-switch/
  -auth, event pipeline, terminal, dictation) so features work over the relay
  unchanged; direct-URL and Electron realtime-proxy paths are untouched.

Pairing & UX
- Relay section in Settings -> Remote Instances (live status, QR/link pairing,
  revocation via the existing client-token list) and the mobile connect flow.
- Frame batching and idle-gated keepalive keep tunnel message volume low
  without affecting streaming smoothness.

Security
- The tunnel is transport only; the server authenticates every tunneled
  request exactly as for a direct remote client.
  fragments only. The relay stores no keys, tokens, or payloads.

Operability
- The endpoint can be pinned to a self-hosted rel
  paired clients inherit it from the offer automatically.
- Relay module DOCUMENTATION.md and a relay-trans
  invariants that future WebSocket/streaming changes must follow.

The relay transport is complete and tested; the UI for enabling and pairing
is gated behind openchamber_relay_gate and stays
2026-07-08 03:44:02 +03:00

74 lines
3.0 KiB
JavaScript

// Host relay identity: the EXISTING ECDSA P-256 signing keypair (shared with
// the push relay via signing-key.js — same storage, same serverId) plus a NEW
// long-lived ECDH P-256 encryption keypair for the E2EE channel (WebCrypto
// keys are single-purpose, so signing and encryption keys must differ).
// The encryption keypair is persisted as `settings.relayEncryptionKey =
// { privateJwk, publicJwk }`, mirroring the relaySigningKey precedent.
import {
canonicalPublicJwkString,
deriveServerId,
getOrCreateRelaySigningKeypair,
signRelayMessage,
} from './signing-key.js';
import { exportPublicKeyJwk, generateEcdhKeyPair, importEcdhPrivateKey } from './e2ee.js';
const isJwkPair = (value) => Boolean(value && typeof value === 'object' && value.privateJwk && value.publicJwk);
/**
* @param {{ crypto: typeof import('node:crypto'), readSettingsFromDiskMigrated: () => Promise<object>, writeSettingsToDisk: (settings: object) => Promise<void> }} deps
*/
export const createRelayIdentityRuntime = (deps) => {
const { crypto, readSettingsFromDiskMigrated, writeSettingsToDisk } = deps;
let cachedIdentity = null;
const getOrCreateEncryptionKeypair = async () => {
const settings = await readSettingsFromDiskMigrated();
const existing = settings?.relayEncryptionKey;
if (isJwkPair(existing)) {
return existing;
}
const keyPair = await generateEcdhKeyPair();
const privateJwk = await globalThis.crypto.subtle.exportKey('jwk', keyPair.privateKey);
const publicJwk = await exportPublicKeyJwk(keyPair.publicKey);
await writeSettingsToDisk({ ...settings, relayEncryptionKey: { privateJwk, publicJwk } });
return { privateJwk, publicJwk };
};
/**
* @returns {Promise<{
* serverId: string,
* hostEncPubJwk: JsonWebKey,
* hostEncPrivateKey: CryptoKey,
* signRelayAuth: (role: string, connectionId?: string | null) => { ts: number, sig: string, pk: string },
* }>}
*/
const getRelayIdentity = async () => {
if (cachedIdentity) return cachedIdentity;
const signing = await getOrCreateRelaySigningKeypair({ crypto, readSettingsFromDiskMigrated, writeSettingsToDisk });
const serverId = deriveServerId({ crypto }, signing.publicJwk);
const encryption = await getOrCreateEncryptionKeypair();
const hostEncPrivateKey = await importEcdhPrivateKey(encryption.privateJwk);
const pk = Buffer.from(canonicalPublicJwkString(signing.publicJwk), 'utf8').toString('base64url');
// Relay-layer auth for host-control / host-data upgrades. Signature payload
// string is `${ts}.${serverId}.${role}.${connectionId ?? ""}` (spec Layer 1).
const signRelayAuth = (role, connectionId) => {
const ts = Date.now();
const sig = signRelayMessage({ crypto }, signing.privateKey, `${ts}.${serverId}.${role}.${connectionId ?? ''}`);
return { ts, sig, pk };
};
cachedIdentity = {
serverId,
hostEncPubJwk: encryption.publicJwk,
hostEncPrivateKey,
signRelayAuth,
};
return cachedIdentity;
};
return { getRelayIdentity };
};