signal-desktop/ts/textsecure/SocketManager.ts
2024-08-06 14:21:15 -07:00

944 lines
27 KiB
TypeScript

// Copyright 2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import type { Net } from '@signalapp/libsignal-client';
import URL from 'url';
import type { RequestInit, Response } from 'node-fetch';
import { Headers } from 'node-fetch';
import type { connection as WebSocket } from 'websocket';
import qs from 'querystring';
import EventListener from 'events';
import { AbortableProcess } from '../util/AbortableProcess';
import { strictAssert } from '../util/assert';
import {
BackOff,
EXTENDED_FIBONACCI_TIMEOUTS,
FIBONACCI_TIMEOUTS,
} from '../util/BackOff';
import * as durations from '../util/durations';
import { sleep } from '../util/sleep';
import { drop } from '../util/drop';
import type { ProxyAgent } from '../util/createProxyAgent';
import { createProxyAgent } from '../util/createProxyAgent';
import { SocketStatus } from '../types/SocketStatus';
import * as Errors from '../types/errors';
import * as Bytes from '../Bytes';
import * as log from '../logging/log';
import type {
IncomingWebSocketRequest,
IWebSocketResource,
WebSocketResourceOptions,
} from './WebsocketResources';
import WebSocketResource, {
connectAuthenticatedLibsignal,
connectUnauthenticatedLibsignal,
TransportOption,
WebSocketResourceWithShadowing,
} from './WebsocketResources';
import { ConnectTimeoutError, HTTPError } from './Errors';
import type { IRequestHandler, WebAPICredentials } from './Types.d';
import { connect as connectWebSocket } from './WebSocket';
import { isAlpha, isBeta, isStaging } from '../util/version';
const FIVE_MINUTES = 5 * durations.MINUTE;
const JITTER = 5 * durations.SECOND;
const OFFLINE_KEEPALIVE_TIMEOUT_MS = 5 * durations.SECOND;
export const UNAUTHENTICATED_CHANNEL_NAME = 'unauthenticated';
export const AUTHENTICATED_CHANNEL_NAME = 'authenticated';
export type SocketManagerOptions = Readonly<{
url: string;
certificateAuthority: string;
version: string;
proxyUrl?: string;
hasStoriesDisabled: boolean;
}>;
// This class manages two websocket resources:
//
// - Authenticated IWebSocketResource which uses supplied WebAPICredentials and
// automatically reconnects on closed socket (using back off)
// - Unauthenticated IWebSocketResource that is created on the first outgoing
// unauthenticated request and is periodically rotated (5 minutes since first
// activity on the socket).
//
// Incoming requests on authenticated resource are funneled into the registered
// request handlers (`registerRequestHandler`) or queued internally until at
// least one such request handler becomes available.
//
// Incoming requests on unauthenticated resource are not currently supported.
// IWebSocketResource is responsible for their immediate termination.
export class SocketManager extends EventListener {
private backOff = new BackOff(FIBONACCI_TIMEOUTS, {
jitter: JITTER,
});
private authenticated?: AbortableProcess<IWebSocketResource>;
private unauthenticated?: AbortableProcess<IWebSocketResource>;
private unauthenticatedExpirationTimer?: NodeJS.Timeout;
private credentials?: WebAPICredentials;
private lazyProxyAgent?: Promise<ProxyAgent>;
private status = SocketStatus.CLOSED;
private requestHandlers = new Set<IRequestHandler>();
private incomingRequestQueue = new Array<IncomingWebSocketRequest>();
private isNavigatorOffline = false;
private privIsOnline: boolean | undefined;
private isRemotelyExpired = false;
private hasStoriesDisabled: boolean;
private reconnectController: AbortController | undefined;
constructor(
private readonly libsignalNet: Net.Net,
private readonly options: SocketManagerOptions
) {
super();
this.hasStoriesDisabled = options.hasStoriesDisabled;
}
public getStatus(): SocketStatus {
return this.status;
}
private markOffline() {
if (this.privIsOnline !== false) {
this.privIsOnline = false;
this.emit('offline');
}
}
// Update WebAPICredentials and reconnect authenticated resource if
// credentials changed
public async authenticate(credentials: WebAPICredentials): Promise<void> {
if (this.isRemotelyExpired) {
throw new HTTPError('SocketManager remotely expired', {
code: 0,
headers: {},
stack: new Error().stack,
});
}
const { username, password } = credentials;
if (!username && !password) {
log.warn('SocketManager authenticate was called without credentials');
return;
}
if (
this.credentials &&
this.credentials.username === username &&
this.credentials.password === password &&
this.authenticated
) {
try {
await this.authenticated.getResult();
} catch (error) {
log.warn(
'SocketManager: failed to wait for existing authenticated socket ' +
` due to error: ${Errors.toLogFormat(error)}`
);
}
return;
}
this.credentials = credentials;
log.info(
'SocketManager: connecting authenticated socket ' +
`(hasStoriesDisabled=${this.hasStoriesDisabled})`
);
this.setStatus(SocketStatus.CONNECTING);
const proxyAgent = await this.getProxyAgent();
const useLibsignalTransport =
window.Signal.RemoteConfig.isEnabled(
'desktop.experimentalTransport.enableAuth'
) && this.transportOption(proxyAgent) === TransportOption.Libsignal;
const process = useLibsignalTransport
? connectAuthenticatedLibsignal({
libsignalNet: this.libsignalNet,
name: AUTHENTICATED_CHANNEL_NAME,
credentials: this.credentials,
handler: (req: IncomingWebSocketRequest): void => {
this.queueOrHandleRequest(req);
},
receiveStories: !this.hasStoriesDisabled,
})
: this.connectResource({
name: AUTHENTICATED_CHANNEL_NAME,
path: '/v1/websocket/',
query: { login: username, password },
resourceOptions: {
name: AUTHENTICATED_CHANNEL_NAME,
keepalive: { path: '/v1/keepalive' },
handleRequest: (req: IncomingWebSocketRequest): void => {
this.queueOrHandleRequest(req);
},
},
extraHeaders: {
'X-Signal-Receive-Stories': String(!this.hasStoriesDisabled),
},
proxyAgent,
});
// Cancel previous connect attempt or close socket
this.authenticated?.abort();
this.authenticated = process;
const reconnect = async (): Promise<void> => {
if (this.isRemotelyExpired) {
log.info('SocketManager: remotely expired, not reconnecting');
return;
}
const timeout = this.backOff.getAndIncrement();
log.info(
'SocketManager: reconnecting authenticated socket ' +
`after ${timeout}ms`
);
const reconnectController = new AbortController();
this.reconnectController = reconnectController;
try {
await sleep(timeout, reconnectController.signal);
} catch {
log.info('SocketManager: reconnect cancelled');
return;
} finally {
if (this.reconnectController === reconnectController) {
this.reconnectController = undefined;
}
}
if (this.authenticated) {
log.info('SocketManager: authenticated socket already connecting');
return;
}
strictAssert(this.credentials !== undefined, 'Missing credentials');
try {
await this.authenticate(this.credentials);
} catch (error) {
log.info(
'SocketManager: authenticated socket failed to reconnect ' +
`due to error ${Errors.toLogFormat(error)}`
);
return reconnect();
}
};
let authenticated: IWebSocketResource;
try {
authenticated = await process.getResult();
this.setStatus(SocketStatus.OPEN);
} catch (error) {
log.warn(
'SocketManager: authenticated socket connection failed with ' +
`error: ${Errors.toLogFormat(error)}`
);
// The socket was deliberately closed, don't follow up
if (this.authenticated !== process) {
return;
}
this.dropAuthenticated(process);
if (error instanceof HTTPError) {
const { code } = error;
if (code === 401 || code === 403) {
this.emit('authError', error);
return;
}
if (!(code >= 500 && code <= 599) && code !== -1) {
// No reconnect attempt should be made
return;
}
if (code === -1) {
this.markOffline();
}
} else if (error instanceof ConnectTimeoutError) {
this.markOffline();
}
drop(reconnect());
return;
}
log.info(
`SocketManager: connected authenticated socket (localPort: ${authenticated.localPort()})`
);
window.logAuthenticatedConnect?.();
this.backOff.reset();
authenticated.addEventListener('close', ({ code, reason }): void => {
if (this.authenticated !== process) {
return;
}
log.warn(
'SocketManager: authenticated socket closed ' +
`with code=${code} and reason=${reason}`
);
this.dropAuthenticated(process);
if (code === 3000) {
// Intentional disconnect
return;
}
if (code === 4409) {
log.error('SocketManager: got 4409, connected on another device');
return;
}
drop(reconnect());
});
}
// Either returns currently connecting/active authenticated
// IWebSocketResource or connects a fresh one.
public async getAuthenticatedResource(): Promise<IWebSocketResource> {
if (!this.authenticated) {
strictAssert(this.credentials !== undefined, 'Missing credentials');
await this.authenticate(this.credentials);
}
strictAssert(this.authenticated !== undefined, 'Authentication failed');
return this.authenticated.getResult();
}
// Creates new IWebSocketResource for AccountManager's provisioning
public async getProvisioningResource(
handler: IRequestHandler
): Promise<IWebSocketResource> {
if (this.isRemotelyExpired) {
throw new Error('Remotely expired, not connecting provisioning socket');
}
return this.connectResource({
name: 'provisioning',
path: '/v1/websocket/provisioning/',
proxyAgent: await this.getProxyAgent(),
resourceOptions: {
name: 'provisioning',
handleRequest: (req: IncomingWebSocketRequest): void => {
handler.handleRequest(req);
},
keepalive: { path: '/v1/keepalive/provisioning' },
},
}).getResult();
}
// Creates new WebSocket for Art Creator provisioning
public async connectExternalSocket({
url,
extraHeaders,
}: {
url: string;
extraHeaders?: Record<string, string>;
}): Promise<WebSocket> {
const proxyAgent = await this.getProxyAgent();
return connectWebSocket({
name: 'art-creator-provisioning',
url,
version: this.options.version,
proxyAgent,
extraHeaders,
createResource(socket: WebSocket): WebSocket {
return socket;
},
}).getResult();
}
// Fetch-compatible wrapper around underlying unauthenticated/authenticated
// websocket resources. This wrapper supports only limited number of features
// of node-fetch despite being API compatible.
public async fetch(url: string, init: RequestInit): Promise<Response> {
const headers = new Headers(init.headers);
let resource: IWebSocketResource;
if (this.isAuthenticated(headers)) {
resource = await this.getAuthenticatedResource();
} else {
resource = await this.getUnauthenticatedResource();
await this.startUnauthenticatedExpirationTimer(resource);
}
const { path } = URL.parse(url);
strictAssert(path, "Fetch can't have empty path");
const { method = 'GET', body, timeout } = init;
let bodyBytes: Uint8Array | undefined;
if (body === undefined) {
bodyBytes = undefined;
} else if (body instanceof Uint8Array) {
bodyBytes = body;
} else if (body instanceof ArrayBuffer) {
throw new Error('Unsupported body type: ArrayBuffer');
} else if (typeof body === 'string') {
bodyBytes = Bytes.fromString(body);
} else {
throw new Error(`Unsupported body type: ${typeof body}`);
}
return resource.sendRequest({
verb: method,
path,
body: bodyBytes,
headers: Array.from(headers.entries()),
timeout,
});
}
public registerRequestHandler(handler: IRequestHandler): void {
this.requestHandlers.add(handler);
const queue = this.incomingRequestQueue;
if (queue.length === 0) {
return;
}
log.info(
`SocketManager: processing ${queue.length} queued incoming requests`
);
this.incomingRequestQueue = [];
for (const req of queue) {
this.queueOrHandleRequest(req);
}
}
public unregisterRequestHandler(handler: IRequestHandler): void {
this.requestHandlers.delete(handler);
}
public async onHasStoriesDisabledChange(newValue: boolean): Promise<void> {
if (this.hasStoriesDisabled === newValue) {
return;
}
this.hasStoriesDisabled = newValue;
log.info(
`SocketManager: reconnecting after setting hasStoriesDisabled=${newValue}`
);
await this.reconnect();
}
public async reconnect(): Promise<void> {
log.info('SocketManager.reconnect: starting...');
const { authenticated, unauthenticated } = this;
if (authenticated) {
authenticated.abort();
this.dropAuthenticated(authenticated);
}
if (unauthenticated) {
unauthenticated.abort();
this.dropUnauthenticated(unauthenticated);
}
if (this.credentials) {
this.backOff.reset();
// Cancel old reconnect attempt
this.reconnectController?.abort();
// Start the new attempt
await this.authenticate(this.credentials);
}
log.info('SocketManager.reconnect: complete.');
}
// Force keep-alive checks on WebSocketResources
public async check(): Promise<void> {
log.info('SocketManager.check');
await Promise.all([
this.checkResource(this.authenticated),
this.checkResource(this.unauthenticated),
]);
}
public async onNavigatorOnline(): Promise<void> {
log.info('SocketManager.onNavigatorOnline');
this.isNavigatorOffline = false;
this.backOff.reset(FIBONACCI_TIMEOUTS);
// Reconnect earlier if waiting
if (this.credentials !== undefined) {
this.reconnectController?.abort();
await this.authenticate(this.credentials);
}
}
public async onNavigatorOffline(): Promise<void> {
log.info('SocketManager.onNavigatorOffline');
this.isNavigatorOffline = true;
this.backOff.reset(EXTENDED_FIBONACCI_TIMEOUTS);
await this.check();
}
public async onRemoteExpiration(): Promise<void> {
log.info('SocketManager.onRemoteExpiration');
this.isRemotelyExpired = true;
// Cancel reconnect attempt if any
this.reconnectController?.abort();
}
public async logout(): Promise<void> {
const { authenticated } = this;
if (authenticated) {
authenticated.abort();
this.dropAuthenticated(authenticated);
}
this.credentials = undefined;
}
public get isOnline(): boolean | undefined {
return this.privIsOnline;
}
//
// Private
//
private setStatus(status: SocketStatus): void {
if (this.status === status) {
return;
}
this.status = status;
this.emit('statusChange');
if (this.status === SocketStatus.OPEN && !this.privIsOnline) {
this.privIsOnline = true;
this.emit('online');
}
}
private transportOption(proxyAgent: ProxyAgent | undefined): TransportOption {
const { hostname } = URL.parse(this.options.url);
// transport experiment doesn't support proxy
if (proxyAgent || hostname == null || !hostname.endsWith('signal.org')) {
return TransportOption.Original;
}
// in staging, switch to using libsignal transport
if (isStaging(this.options.version)) {
return TransportOption.Libsignal;
}
// in alpha, switch to using libsignal transport, unless user opts out,
// in which case switching to shadowing
if (isAlpha(this.options.version)) {
const configValue = window.Signal.RemoteConfig.isEnabled(
'desktop.experimentalTransportEnabled.alpha'
);
return configValue
? TransportOption.Libsignal
: TransportOption.ShadowingHigh;
}
// in beta, switch to using 'ShadowingHigh' mode, unless user opts out,
// in which case switching to `ShadowingLow`
if (isBeta(this.options.version)) {
const configValue = window.Signal.RemoteConfig.isEnabled(
'desktop.experimentalTransportEnabled.beta'
);
return configValue
? TransportOption.ShadowingHigh
: TransportOption.ShadowingLow;
}
const configValue = window.Signal.RemoteConfig.isEnabled(
'desktop.experimentalTransportEnabled.prod'
);
return configValue
? TransportOption.ShadowingLow
: TransportOption.Original;
}
private connectLibsignalUnauthenticated(): AbortableProcess<IWebSocketResource> {
return connectUnauthenticatedLibsignal({
libsignalNet: this.libsignalNet,
name: UNAUTHENTICATED_CHANNEL_NAME,
});
}
private async getUnauthenticatedResource(): Promise<IWebSocketResource> {
if (this.unauthenticated) {
return this.unauthenticated.getResult();
}
if (this.isRemotelyExpired) {
throw new HTTPError('SocketManager remotely expired', {
code: 0,
headers: {},
stack: new Error().stack,
});
}
log.info('SocketManager: connecting unauthenticated socket');
const proxyAgent = await this.getProxyAgent();
const transportOption = this.transportOption(proxyAgent);
log.info(
`SocketManager: connecting unauthenticated socket, transport option [${transportOption}]`
);
let process: AbortableProcess<IWebSocketResource>;
if (transportOption === TransportOption.Libsignal) {
process = this.connectLibsignalUnauthenticated();
} else {
process = this.connectResource({
name: UNAUTHENTICATED_CHANNEL_NAME,
path: '/v1/websocket/',
proxyAgent,
resourceOptions: {
name: UNAUTHENTICATED_CHANNEL_NAME,
keepalive: { path: '/v1/keepalive' },
transportOption,
},
});
}
this.unauthenticated = process;
let unauthenticated: IWebSocketResource;
try {
unauthenticated = await this.unauthenticated.getResult();
} catch (error) {
log.info(
'SocketManager: failed to connect unauthenticated socket ' +
` due to error: ${Errors.toLogFormat(error)}`
);
this.dropUnauthenticated(process);
throw error;
}
log.info(
`SocketManager: connected unauthenticated socket (localPort: ${unauthenticated.localPort()})`
);
unauthenticated.addEventListener('close', ({ code, reason }): void => {
if (this.unauthenticated !== process) {
return;
}
log.warn(
'SocketManager: unauthenticated socket closed ' +
`with code=${code} and reason=${reason}`
);
this.dropUnauthenticated(process);
});
return this.unauthenticated.getResult();
}
private connectResource({
name,
path,
proxyAgent,
resourceOptions,
query = {},
extraHeaders = {},
}: {
name: string;
path: string;
proxyAgent: ProxyAgent | undefined;
resourceOptions: WebSocketResourceOptions;
query?: Record<string, string>;
extraHeaders?: Record<string, string>;
}): AbortableProcess<IWebSocketResource> {
const queryWithDefaults = {
agent: 'OWD',
version: this.options.version,
...query,
};
const url = `${this.options.url}${path}?${qs.encode(queryWithDefaults)}`;
const { version } = this.options;
const start = performance.now();
const webSocketResourceConnection = connectWebSocket({
name,
url,
version,
certificateAuthority: this.options.certificateAuthority,
proxyAgent,
extraHeaders,
createResource(socket: WebSocket): WebSocketResource {
const duration = (performance.now() - start).toFixed(1);
log.info(
`WebSocketResource(${resourceOptions.name}) connected in ${duration}ms`
);
return new WebSocketResource(socket, resourceOptions);
},
});
const shadowingModeEnabled =
!resourceOptions.transportOption ||
resourceOptions.transportOption === TransportOption.Original;
return shadowingModeEnabled
? webSocketResourceConnection
: this.connectWithShadowing(webSocketResourceConnection, resourceOptions);
}
/**
* A method that takes in an `AbortableProcess<>` that establishes
* a `WebSocketResource` connection and wraps it in a process
* that also tries to establish a `LibsignalWebSocketResource` connection.
*
* The shadowing connection will not block the main one (e.g. if it takes
* longer to connect) and an error in the shadowing connection will not
* affect the overall behavior.
*
* @param mainConnection an `AbortableProcess<WebSocketResource>` responsible
* for establishing a Desktop system WebSocket connection.
* @param options `WebSocketResourceOptions` options
* @private
*/
private connectWithShadowing(
mainConnection: AbortableProcess<WebSocketResource>,
options: WebSocketResourceOptions
): AbortableProcess<IWebSocketResource> {
// creating an `AbortableProcess` of libsignal websocket connection
const shadowingConnection = connectUnauthenticatedLibsignal({
libsignalNet: this.libsignalNet,
name: options.name,
});
const shadowWrapper = async () => {
// if main connection results in an error,
// it's propagated as the error of the resulting process
const mainSocket = await mainConnection.resultPromise;
// here, we're not awaiting on `shadowingConnection.resultPromise`
// and just letting `WebSocketResourceWithShadowing`
// initiate and handle the result of the shadowing connection attempt
return new WebSocketResourceWithShadowing(
mainSocket,
shadowingConnection,
options
);
};
return new AbortableProcess<IWebSocketResource>(
`WebSocketResourceWithShadowing.connect(${options.name})`,
{
abort() {
mainConnection.abort();
shadowingConnection.abort();
},
},
shadowWrapper()
);
}
private async checkResource(
process?: AbortableProcess<IWebSocketResource>
): Promise<void> {
if (!process) {
return;
}
const resource = await process.getResult();
// Force shorter timeout if we think we might be offline
resource.forceKeepAlive(
this.isNavigatorOffline ? OFFLINE_KEEPALIVE_TIMEOUT_MS : undefined
);
}
private dropAuthenticated(
process: AbortableProcess<IWebSocketResource>
): void {
if (this.authenticated !== process) {
return;
}
this.incomingRequestQueue = [];
this.authenticated = undefined;
this.setStatus(SocketStatus.CLOSED);
}
private dropUnauthenticated(
process: AbortableProcess<IWebSocketResource>
): void {
if (this.unauthenticated !== process) {
return;
}
this.unauthenticated = undefined;
if (!this.unauthenticatedExpirationTimer) {
return;
}
clearTimeout(this.unauthenticatedExpirationTimer);
this.unauthenticatedExpirationTimer = undefined;
}
private async startUnauthenticatedExpirationTimer(
expected: IWebSocketResource
): Promise<void> {
const process = this.unauthenticated;
strictAssert(
process !== undefined,
'Unauthenticated socket must be connected'
);
const unauthenticated = await process.getResult();
strictAssert(
unauthenticated === expected,
'Unauthenticated resource should be the same'
);
if (this.unauthenticatedExpirationTimer) {
return;
}
log.info(
'SocketManager: starting expiration timer for unauthenticated socket'
);
this.unauthenticatedExpirationTimer = setTimeout(async () => {
log.info(
'SocketManager: shutting down unauthenticated socket after timeout'
);
unauthenticated.shutdown();
// The socket is either deliberately closed or reconnected already
if (this.unauthenticated !== process) {
return;
}
this.dropUnauthenticated(process);
try {
await this.getUnauthenticatedResource();
} catch (error) {
log.warn(
'SocketManager: failed to reconnect unauthenticated socket ' +
`due to error: ${Errors.toLogFormat(error)}`
);
}
}, FIVE_MINUTES);
}
private queueOrHandleRequest(req: IncomingWebSocketRequest): void {
if (this.requestHandlers.size === 0) {
this.incomingRequestQueue.push(req);
log.info(
'SocketManager: request handler unavailable, ' +
`queued request. Queue size: ${this.incomingRequestQueue.length}`
);
return;
}
for (const handlers of this.requestHandlers) {
try {
handlers.handleRequest(req);
} catch (error) {
log.warn(
'SocketManager: got exception while handling incoming request, ' +
`error: ${Errors.toLogFormat(error)}`
);
}
}
}
private isAuthenticated(headers: Headers): boolean {
if (!this.credentials) {
return false;
}
const authorization = headers.get('Authorization');
if (!authorization) {
return false;
}
const [basic, base64] = authorization.split(/\s+/, 2);
if (basic.toLowerCase() !== 'basic' || !base64) {
return false;
}
const [username, password] = Bytes.toString(Bytes.fromBase64(base64)).split(
':',
2
);
return (
username === this.credentials.username &&
password === this.credentials.password
);
}
private async getProxyAgent(): Promise<ProxyAgent | undefined> {
if (this.options.proxyUrl && !this.lazyProxyAgent) {
// Cache the promise so that we don't import concurrently.
this.lazyProxyAgent = createProxyAgent(this.options.proxyUrl);
}
return this.lazyProxyAgent;
}
// EventEmitter types
public override on(
type: 'authError',
callback: (error: HTTPError) => void
): this;
public override on(type: 'statusChange', callback: () => void): this;
public override on(type: 'online', callback: () => void): this;
public override on(type: 'offline', callback: () => void): this;
public override on(
type: string | symbol,
// eslint-disable-next-line @typescript-eslint/no-explicit-any
listener: (...args: Array<any>) => void
): this {
return super.on(type, listener);
}
public override emit(type: 'authError', error: HTTPError): boolean;
public override emit(type: 'statusChange'): boolean;
public override emit(type: 'online'): boolean;
public override emit(type: 'offline'): boolean;
// eslint-disable-next-line @typescript-eslint/no-explicit-any
public override emit(type: string | symbol, ...args: Array<any>): boolean {
return super.emit(type, ...args);
}
}