fix(ActivityPub): URIとURLが一致しない場合、同じドメイン内のサブドメインの1階層の違いまでは許容する (#859)

packages/backend/package.json

@@ -156,6 +156,7 @@
 		"pkce-challenge": "4.1.0",
 		"probe-image-size": "7.2.3",
 		"promise-limit": "2.7.0",
+		"psl": "1.15.0",
 		"pug": "3.0.3",
 		"punycode.js": "2.3.1",
 		"qrcode": "1.5.4",
@@ -216,6 +217,7 @@
 		"@types/oauth2orize": "1.11.5",
 		"@types/oauth2orize-pkce": "0.1.2",
 		"@types/pg": "8.11.10",
+		"@types/psl": "1.1.3",
 		"@types/pug": "2.0.10",
 		"@types/punycode.js": "npm:@types/[email protected]",
 		"@types/qrcode": "1.5.5",

packages/backend/src/core/HttpRequestService.ts

@@ -13,10 +13,10 @@ import { HttpProxyAgent, HttpsProxyAgent } from 'hpagent';
 import { Inject, Injectable } from '@nestjs/common';
 import { DI } from '@/di-symbols.js';
 import type { Config } from '@/config.js';
+import { UtilityService } from '@/core/UtilityService.js';
 import { StatusError } from '@/misc/status-error.js';
 import { bindThis } from '@/decorators.js';
 import { validateContentTypeSetAsActivityPub } from '@/core/activitypub/misc/validator.js';
-import { assertActivityMatchesUrls } from '@/core/activitypub/misc/check-against-url.js';
 import type { IObject } from '@/core/activitypub/type.js';
 import type { Response } from 'node-fetch';
 import type { URL } from 'node:url';
@@ -145,6 +145,8 @@ export class HttpRequestService {
 	constructor(
 		@Inject(DI.config)
 		private config: Config,
+
+		private utilityService: UtilityService,
 	) {
 		const cache = new CacheableLookup({
 			maxTtl: 3600,	// 1hours
@@ -232,7 +234,7 @@ export class HttpRequestService {
 		const finalUrl = res.url; // redirects may have been involved
 		const activity = await res.json() as IObject;
 
-		assertActivityMatchesUrls(activity, [finalUrl]);
+		this.utilityService.assertActivityRelatedToUrl(activity, finalUrl);
 
 		return activity;
 	}

packages/backend/src/core/UtilityService.ts

@@ -4,12 +4,15 @@
  */
 
 import { URL } from 'node:url';
+import { isIP } from 'node:net';
 import punycode from 'punycode.js';
+import psl from 'psl';
 import RE2 from 're2';
 import { Inject, Injectable } from '@nestjs/common';
 import { DI } from '@/di-symbols.js';
 import type { Config } from '@/config.js';
 import { bindThis } from '@/decorators.js';
+import type { IObject } from '@/core/activitypub/type.js';
 
 @Injectable()
 export class UtilityService {
@@ -93,4 +96,102 @@ export class UtilityService {
 		// ref: https://url.spec.whatwg.org/#host-serializing
 		return new URL(uri).host;
 	}
+
+	@bindThis
+	public isRelatedHosts(hostA: string, hostB: string): boolean {
+		// hostA と hostB は呼び出す側で正規化済みであることを前提とする
+
+		// ポート番号が付いている可能性がある場合、ポート番号を除去するためにもう一度正規化
+		if (hostA.includes(':')) hostA = new URL(`urn://${hostA}`).hostname;
+		if (hostB.includes(':')) hostB = new URL(`urn://${hostB}`).hostname;
+
+		// ホストが完全一致している場合は true
+		if (hostA === hostB) {
+			return true;
+		}
+
+		// -----------------------------
+		// 1. IPアドレスの場合の処理
+		// -----------------------------
+		const aIpVersion = isIP(hostA);
+		const bIpVersion = isIP(hostB);
+		if (aIpVersion !== 0 || bIpVersion !== 0) {
+			// どちらかが IP の場合、完全一致以外は false
+			return false;
+		}
+
+		// -----------------------------
+		// 2. ホストの場合の処理
+		// -----------------------------
+		const parsedA = psl.parse(hostA);
+		const parsedB = psl.parse(hostB);
+
+		// どちらか一方でもパース失敗 or eTLD+1が異なる場合は false
+		if (parsedA.error || parsedB.error || parsedA.domain !== parsedB.domain) {
+			return false;
+		}
+
+		// -----------------------------
+		// 3. サブドメインの比較
+		// -----------------------------
+		// サブドメイン部分が後方一致で階層差が1以内かどうかを判定する。
+		// 完全一致だと既に true で返しているので、ここでは完全一致以外の場合のみの判定
+		// 例:
+		//  subA = "www",         subB = ""          => true  (1階層差)
+		//  subA = "alice.users", subB = "users"     => true  (1階層差)
+		//  subA = "alice.users", subB = "bob.users" => true  (1階層差)
+		//  subA = "alice.users", subB = ""          => false (2階層差)
+
+		const labelsA = parsedA.subdomain?.split('.') ?? [];
+		const levelsA = labelsA.length;
+		const labelsB = parsedB.subdomain?.split('.') ?? [];
+		const levelsB = labelsB.length;
+
+		// 後ろ(右)から一致している部分をカウント
+		let i = 0;
+		while (
+			i < levelsA &&
+			i < levelsB &&
+			labelsA[levelsA - 1 - i] === labelsB[levelsB - 1 - i]
+			) {
+			i++;
+		}
+
+		// 後方一致していないラベルの数 = (総数 - 一致数)
+		const unmatchedA = levelsA - i;
+		const unmatchedB = levelsB - i;
+
+		// 不一致ラベルが1階層以内なら true
+		return Math.max(unmatchedA, unmatchedB) <= 1;
+	}
+
+	@bindThis
+	public isRelatedUris(uriA: string, uriB: string): boolean {
+		// URI が完全一致している場合は true
+		if (uriA === uriB) {
+			return true;
+		}
+
+		const hostA = this.extractHost(uriA);
+		const hostB = this.extractHost(uriB);
+
+		return this.isRelatedHosts(hostA, hostB);
+	}
+
+	@bindThis
+	public assertActivityRelatedToUrl(activity: IObject, url: string): void {
+		if (activity.id && this.isRelatedUris(activity.id, url)) return;
+
+		if (activity.url) {
+			if (!Array.isArray(activity.url)) {
+				if (typeof(activity.url) === 'string' && this.isRelatedUris(activity.url, url)) return;
+				if (typeof(activity.url) === 'object' && activity.url.href && this.isRelatedUris(activity.url.href, url)) return;
+			} else {
+				if (activity.url.some(x => typeof(x) === 'string' && this.isRelatedUris(x, url))) return;
+				if (activity.url.some(x => typeof(x) === 'object' && x.href && this.isRelatedUris(x.href, url))) return;
+			}
+		}
+
+		throw new Error(`Invalid object: neither id(${activity.id}) nor url(${activity.url}) related to ${url}`);
+	}
 }

packages/backend/src/core/activitypub/ApRequestService.ts

@@ -17,7 +17,6 @@ import { LoggerService } from '@/core/LoggerService.js';
 import { bindThis } from '@/decorators.js';
 import type Logger from '@/logger.js';
 import { validateContentTypeSetAsActivityPub } from '@/core/activitypub/misc/validator.js';
-import { assertActivityMatchesUrls } from '@/core/activitypub/misc/check-against-url.js';
 import type { IObject } from './type.js';
 
 type Request = {
@@ -182,6 +181,7 @@ export class ApRequestService {
 	 * Get AP object with http-signature
 	 * @param user http-signature user
 	 * @param url URL to fetch
+	 * @param followAlternate If true, follow alternate link tag in HTML
 	 */
 	@bindThis
 	public async signedGet(url: string, user: { id: MiUser['id'] }, followAlternate?: boolean): Promise<unknown> {
@@ -220,7 +220,7 @@ export class ApRequestService {
 				const alternate = fragment.querySelector('head > link[rel="alternate"][type="application/activity+json"]');
 				if (alternate) {
 					const href = alternate.getAttribute('href');
-					if (href && this.utilityService.extractHost(url) === this.utilityService.extractHost(href)) {
+					if (href && this.utilityService.isRelatedUris(url, href)) {
 						return await this.signedGet(href, user, false);
 					}
 				}
@@ -234,7 +234,7 @@ export class ApRequestService {
 		const finalUrl = res.url; // redirects may have been involved
 		const activity = await res.json() as IObject;
 
-		assertActivityMatchesUrls(activity, [finalUrl]);
+		this.utilityService.assertActivityRelatedToUrl(activity, finalUrl);
 
 		return activity;
 	}

packages/backend/src/core/activitypub/ApResolverService.ts

@@ -128,8 +128,8 @@ export class Resolver {
 			throw new Error('invalid AP object: missing id');
 		}
 
-		if (this.utilityService.extractHost(object.id) !== this.utilityService.extractHost(value)) {
-			throw new Error(`invalid AP object ${value}: id ${object.id} has different host`);
+		if (!this.utilityService.isRelatedUris(object.id, value)) {
+			throw new Error(`invalid AP object ${value}: id ${object.id} has unrelated host`);
 		}
 
 		return object;

packages/backend/src/core/activitypub/models/ApNoteService.ts

@@ -89,24 +89,31 @@ export class ApNoteService {
 		}
 
 		let actualHost = object.id && this.utilityService.extractHost(object.id);
-		if (actualHost && expectedHost !== actualHost) {
-			return new IdentifiableError('d450b8a9-48e4-4dab-ae36-f4db763fda7c', `invalid Note: id has different host. expected: ${expectedHost}, actual: ${actualHost}`);
+		if (actualHost && !this.utilityService.isRelatedHosts(expectedHost, actualHost)) {
+			return new IdentifiableError('d450b8a9-48e4-4dab-ae36-f4db763fda7c', `invalid Note: id has unrelated host. expected: ${expectedHost}, actual: ${actualHost}`);
 		}
 
 		actualHost = object.attributedTo && this.utilityService.extractHost(getOneApId(object.attributedTo));
-		if (actualHost && expectedHost !== actualHost) {
-			return new IdentifiableError('d450b8a9-48e4-4dab-ae36-f4db763fda7c', `invalid Note: attributedTo has different host. expected: ${expectedHost}, actual: ${actualHost}`);
+		if (actualHost && !this.utilityService.isRelatedHosts(expectedHost, actualHost)) {
+			return new IdentifiableError('d450b8a9-48e4-4dab-ae36-f4db763fda7c', `invalid Note: attributedTo has unrelated host. expected: ${expectedHost}, actual: ${actualHost}`);
 		}
 
 		if (object.published && !this.idService.isSafeT(new Date(object.published).valueOf())) {
 			return new IdentifiableError('d450b8a9-48e4-4dab-ae36-f4db763fda7c', 'invalid Note: published timestamp is malformed');
 		}
 
-		if (actor) {
-			const attribution = (object.attributedTo) ? getOneApId(object.attributedTo) : actor.uri;
+		if (actor?.uri) {
+			if (!this.utilityService.isRelatedUris(uri, actor.uri)) {
+				return new IdentifiableError('d450b8a9-48e4-4dab-ae36-f4db763fda7c', `invalid Note: object has unrelated host to actor. actor: ${actor.uri}, object: ${uri}`);
+			}
+
+			if (object.id && !this.utilityService.isRelatedUris(object.id, actor.uri)) {
+				return new IdentifiableError('d450b8a9-48e4-4dab-ae36-f4db763fda7c', `invalid Note: id has unrelated host to actor. actor: ${actor.uri}, id: ${object.id}`);
+			}
 
-			if (attribution !== actor.uri) {
-				return new IdentifiableError('d450b8a9-48e4-4dab-ae36-f4db763fda7c', `invalid Note: attribution does not match the actor that send it. attribution: ${attribution}, actor: ${actor.uri}`);
+			const attributedTo = object.attributedTo && getOneApId(object.attributedTo);
+			if (attributedTo && !this.utilityService.isRelatedUris(attributedTo, actor.uri)) {
+				return new IdentifiableError('d450b8a9-48e4-4dab-ae36-f4db763fda7c', `invalid Note: attributedTo has unrelated host to actor. actor: ${actor.uri}, attributedTo: ${attributedTo}`);
 			}
 		}
 
@@ -166,8 +173,8 @@ export class ApNoteService {
 				throw new Error('unexpected schema of note url: ' + url);
 			}
 
-			if (this.utilityService.extractHost(note.id) !== this.utilityService.extractHost(url)) {
-				throw new Error(`note id and url have different host: ${note.id} - ${url}`);
+			if (!this.utilityService.isRelatedUris(note.id, url)) {
+				throw new Error(`note id and url has unrelated host: ${note.id} - ${url}`);
 			}
 		}
 

packages/backend/src/core/activitypub/models/ApPersonService.ts

@@ -152,17 +152,17 @@ export class ApPersonService implements OnModuleInit {
 		}
 
 		let actualHost = this.utilityService.extractHost(x.inbox);
-		if (expectedHost !== actualHost) {
-			throw new Error(`invalid Actor: inbox has different host. expected: ${expectedHost}, actual: ${actualHost}`);
+		if (!this.utilityService.isRelatedHosts(expectedHost, actualHost)) {
+			throw new Error(`invalid Actor: inbox has unrelated host. expected: ${expectedHost}, actual: ${actualHost}`);
 		}
 
 		const sharedInboxObject = x.sharedInbox ?? (x.endpoints ? x.endpoints.sharedInbox : undefined);
 		if (sharedInboxObject != null) {
 			const sharedInbox = getApId(sharedInboxObject);
 			if (!sharedInbox) throw new Error('invalid Actor: wrong shared inbox');
 			actualHost = this.utilityService.extractHost(sharedInbox);
-			if (expectedHost !== actualHost) {
-				throw new Error(`invalid Actor: shared inbox has different host. expected: ${expectedHost}, actual: ${actualHost}`);
+			if (!this.utilityService.isRelatedHosts(expectedHost, actualHost)) {
+				throw new Error(`invalid Actor: shared inbox has unrelated host. expected: ${expectedHost}, actual: ${actualHost}`);
 			}
 		}
 
@@ -172,8 +172,8 @@ export class ApPersonService implements OnModuleInit {
 				const collectionUri = getApId(xCollection);
 				if (!collectionUri) throw new Error(`invalid Actor: wrong ${collection}`);
 				actualHost = this.utilityService.extractHost(collectionUri);
-				if (expectedHost !== actualHost) {
-					throw new Error(`invalid Actor: ${collection} has different host. expected: ${expectedHost}, actual: ${actualHost}`);
+				if (!this.utilityService.isRelatedHosts(expectedHost, actualHost)) {
+					throw new Error(`invalid Actor: ${collection} has unrelated host. expected: ${expectedHost}, actual: ${actualHost}`);
 				}
 			}
 		}
@@ -202,8 +202,8 @@ export class ApPersonService implements OnModuleInit {
 		}
 
 		actualHost = this.utilityService.extractHost(x.id);
-		if (expectedHost !== actualHost) {
-			throw new Error(`invalid Actor: id has different host. expected: ${expectedHost}, actual: ${actualHost}`);
+		if (!this.utilityService.isRelatedHosts(expectedHost, actualHost)) {
+			throw new Error(`invalid Actor: id has unrelated host. expected: ${expectedHost}, actual: ${actualHost}`);
 		}
 
 		if (x.publicKey) {
@@ -212,8 +212,8 @@ export class ApPersonService implements OnModuleInit {
 			}
 
 			actualHost = this.utilityService.extractHost(x.publicKey.id);
-			if (expectedHost !== actualHost) {
-				throw new Error(`invalid Actor: publicKey.id has different host. expected: ${expectedHost}, actual: ${actualHost}`);
+			if (!this.utilityService.isRelatedHosts(expectedHost, actualHost)) {
+				throw new Error(`invalid Actor: publicKey.id has unrelated host. expected: ${expectedHost}, actual: ${actualHost}`);
 			}
 		}
 
@@ -345,8 +345,8 @@ export class ApPersonService implements OnModuleInit {
 				throw new Error('unexpected schema of person url: ' + url);
 			}
 
-			if (this.utilityService.extractHost(person.id) !== this.utilityService.extractHost(url)) {
-				throw new Error(`person id and url have different host: ${person.id} - ${url}`);
+			if (!this.utilityService.isRelatedUris(person.id, url)) {
+				throw new Error(`person id and url has unrelated host: ${person.id} - ${url}`);
 			}
 		}
 
@@ -543,8 +543,8 @@ export class ApPersonService implements OnModuleInit {
 				throw new Error('unexpected schema of person url: ' + url);
 			}
 
-			if (this.utilityService.extractHost(person.id) !== this.utilityService.extractHost(url)) {
-				throw new Error(`person id and url have different host: ${person.id} - ${url}`);
+			if (!this.utilityService.isRelatedUris(person.id, url)) {
+				throw new Error(`person id and url has unrelated host: ${person.id} - ${url}`);
 			}
 		}