Fix IP address rate limit (#8758)

* Fix IP address rate limit

* CHANGELOG

* Tune getIpHash

CHANGELOG.md

@@ -26,7 +26,7 @@ You should also include the user name that made the change.
   Your own theme color may be unset if it was in an invalid format.
   Admins should check their instance settings if in doubt.
 - Perform port diagnosis at startup only when Listen fails @mei23
-- Rate limiting is now also usable for non-authenticated users. @Johann150
+- Rate limiting is now also usable for non-authenticated users. @Johann150 @mei23
   Admins should make sure the reverse proxy sets the `X-Forwarded-For` header to the original address.
 
 ### Bugfixes

packages/backend/src/misc/get-ip-hash.ts

+import IPCIDR from 'ip-cidr';
+
+export function getIpHash(ip: string) {
+	// because a single person may control many IPv6 addresses,
+	// only a /64 subnet prefix of any IP will be taken into account.
+	// (this means for IPv4 the entire address is used)
+	const prefix = IPCIDR.createAddress(ip).mask(64);
+	return 'ip-' + BigInt('0b' + prefix).toString(36);
+}

packages/backend/src/server/api/call.ts

@@ -6,7 +6,7 @@ import endpoints, { IEndpointMeta } from './endpoints.js';
 import { ApiError } from './error.js';
 import { apiLogger } from './logger.js';
 import { AccessToken } from '@/models/entities/access-token.js';
-import IPCIDR from 'ip-cidr';
+import { getIpHash } from '@/misc/get-ip-hash.js';
 
 const accessDenied = {
 	message: 'Access denied.',
@@ -33,18 +33,13 @@ export default async (endpoint: string, user: CacheableLocalUser | null | undefi
 		throw new ApiError(accessDenied);
 	}
 
-	if (ep.meta.requireCredential && ep.meta.limit && !isModerator) {
+	if (ep.meta.limit && !isModerator) {
 		// koa will automatically load the `X-Forwarded-For` header if `proxy: true` is configured in the app.
 		let limitActor: string;
 		if (user) {
 			limitActor = user.id;
 		} else {
-			// because a single person may control many IPv6 addresses,
-			// only a /64 subnet prefix of any IP will be taken into account.
-			// (this means for IPv4 the entire address is used)
-			const ip = IPCIDR.createAddress(ctx.ip).mask(64);
-
-			limitActor = 'ip-' + parseInt(ip, 2).toString(36);
+			limitActor = getIpHash(ctx!.ip);
 		}
 
 		const limit = Object.assign({}, ep.meta.limit);

packages/backend/src/server/api/private/signin.ts

@@ -10,6 +10,7 @@ import { verifyLogin, hash } from '../2fa.js';
 import { randomBytes } from 'node:crypto';
 import { IsNull } from 'typeorm';
 import { limiter } from '../limiter.js';
+import { getIpHash } from '@/misc/get-ip-hash.js';
 
 export default async (ctx: Koa.Context) => {
 	ctx.set('Access-Control-Allow-Origin', config.url);
@@ -27,7 +28,7 @@ export default async (ctx: Koa.Context) => {
 
 	try {
 		// not more than 1 attempt per second and not more than 10 attempts per hour
-		await limiter({ key: 'signin', duration: 60 * 60 * 1000, max: 10, minInterval: 1000 }, ctx.ip);
+		await limiter({ key: 'signin', duration: 60 * 60 * 1000, max: 10, minInterval: 1000 }, getIpHash(ctx.ip));
 	} catch (err) {
 		ctx.status = 429;
 		ctx.body = {