merge: Improve URL validation *FOR STABLE* (!1191)

View MR for information: https://activitypub.software/TransFem-org/Sharkey/-/merge_requests/1191

Approved-by: Hazelnoot <acomputerdog@gmail.com>

1 files changed, 38 insertions, 7 deletions

diff --git a/packages/backend/src/core/HttpRequestService.ts b/packages/backend/src/core/HttpRequestService.ts
index 151097095d..bd72fefe4f 100644
--- a/packages/backend/src/core/HttpRequestService.ts
+++ b/packages/backend/src/core/HttpRequestService.ts
@@ -17,9 +17,9 @@ import { StatusError } from '@/misc/status-error.js';
 import { bindThis } from '@/decorators.js';
 import { validateContentTypeSetAsActivityPub } from '@/core/activitypub/misc/validator.js';
 import type { IObject, IObjectWithId } from '@/core/activitypub/type.js';
-import { ApUtilityService } from './activitypub/ApUtilityService.js';
+import { UtilityService } from '@/core/UtilityService.js';
+import { ApUtilityService } from '@/core/activitypub/ApUtilityService.js';
 import type { Response } from 'node-fetch';
-import type { URL } from 'node:url';
 import type { Socket } from 'node:net';
 
 export type HttpRequestSendOptions = {
@@ -27,7 +27,27 @@ export type HttpRequestSendOptions = {
 	validators?: ((res: Response) => void)[];
 };
 
-export function isPrivateIp(allowedPrivateNetworks: PrivateNetwork[] | undefined, ip: string, port?: number): boolean {
+export async function isPrivateUrl(url: URL, lookup: net.LookupFunction): Promise<boolean> {
+	const ip = await resolveIp(url, lookup);
+	return ip.range() !== 'unicast';
+}
+
+export async function resolveIp(url: URL, lookup: net.LookupFunction) {
+	if (ipaddr.isValid(url.hostname)) {
+		return ipaddr.parse(url.hostname);
+	}
+
+	const resolvedIp = await new Promise<string>((resolve, reject) => {
+		lookup(url.hostname, {}, (err, address) => {
+			if (err) reject(err);
+			else resolve(address as string);
+		});
+	});
+
+	return ipaddr.parse(resolvedIp);
+}
+
+export function isAllowedPrivateIp(allowedPrivateNetworks: PrivateNetwork[] | undefined, ip: string, port?: number): boolean {
 	const parsedIp = ipaddr.parse(ip);
 
 	for (const { cidr, ports } of allowedPrivateNetworks ?? []) {
@@ -44,7 +64,7 @@ export function isPrivateIp(allowedPrivateNetworks: PrivateNetwork[] | undefined
 export function validateSocketConnect(allowedPrivateNetworks: PrivateNetwork[] | undefined, socket: Socket): void {
 	const address = socket.remoteAddress;
 	if (address && ipaddr.isValid(address)) {
-		if (isPrivateIp(allowedPrivateNetworks, address, socket.remotePort)) {
+		if (isAllowedPrivateIp(allowedPrivateNetworks, address, socket.remotePort)) {
 			socket.destroy(new Error(`Blocked address: ${address}`));
 		}
 	}
@@ -128,10 +148,16 @@ export class HttpRequestService {
 	 */
 	public readonly httpsAgent: https.Agent;
 
+	/**
+	 * Get shared DNS resolver
+	 */
+	public readonly lookup: net.LookupFunction;
+
 	constructor(
 		@Inject(DI.config)
 		private config: Config,
 		private readonly apUtilityService: ApUtilityService,
+		private readonly utilityService: UtilityService,
 	) {
 		const cache = new CacheableLookup({
 			maxTtl: 3600,	// 1hours
@@ -139,6 +165,8 @@ export class HttpRequestService {
 			lookup: false,	// nativeのdns.lookupにfallbackしない
 		});
 
+		this.lookup = cache.lookup as unknown as net.LookupFunction;
+
 		const agentOption = {
 			keepAlive: true,
 			keepAliveMsecs: 30 * 1000,
@@ -236,8 +264,6 @@ export class HttpRequestService {
 
 	@bindThis
 	public async getActivityJson(url: string, isLocalAddressAllowed = false, allowAnonymous = false): Promise<IObjectWithId> {
-		this.apUtilityService.assertApUrl(url);
-
 		const res = await this.send(url, {
 			method: 'GET',
 			headers: {
@@ -303,6 +329,7 @@ export class HttpRequestService {
 			timeout?: number,
 			size?: number,
 			isLocalAddressAllowed?: boolean,
+			allowHttp?: boolean,
 		} = {},
 		extra: HttpRequestSendOptions = {
 			throwErrorWhenResponseNotOk: true,
@@ -311,6 +338,10 @@ export class HttpRequestService {
 	): Promise<Response> {
 		const timeout = args.timeout ?? 5000;
 
+		const parsedUrl = new URL(url);
+		const allowHttp = args.allowHttp || await isPrivateUrl(parsedUrl, this.lookup);
+		this.utilityService.assertUrl(parsedUrl, allowHttp);
+
 		const controller = new AbortController();
 		setTimeout(() => {
 			controller.abort();
@@ -318,7 +349,7 @@ export class HttpRequestService {
 
 		const isLocalAddressAllowed = args.isLocalAddressAllowed ?? false;
 
-		const res = await fetch(url, {
+		const res = await fetch(parsedUrl, {
 			method: args.method ?? 'GET',
 			headers: {
 				'User-Agent': this.config.userAgent,