Merge pull request from GHSA-qqrm-9grj-6v32

* maybe ok

* fix

* test wip

* :v:

* fix

* if (res.ok)

* validateContentTypeSetAsJsonLD

* 条件を考慮し直す

* その他の+json接尾辞が付いているメディアタイプも受け容れる

* https://github.com/misskey-dev/misskey-ghsa-qqrm-9grj-6v32/pull/1#discussion_r1490999009

* add `; profile="https://www.w3.org/ns/activitystreams"`

* application/ld+json;

5 files changed, 94 insertions, 14 deletions

diff --git a/packages/backend/src/core/HttpRequestService.ts b/packages/backend/src/core/HttpRequestService.ts
index b36b9f6e3c..7f3cac7c58 100644
--- a/packages/backend/src/core/HttpRequestService.ts
+++ b/packages/backend/src/core/HttpRequestService.ts
@@ -14,9 +14,16 @@ import { DI } from '@/di-symbols.js';
 import type { Config } from '@/config.js';
 import { StatusError } from '@/misc/status-error.js';
 import { bindThis } from '@/decorators.js';
+import { validateContentTypeSetAsActivityPub } from '@/core/activitypub/misc/validator.js';
+import type { IObject } from '@/core/activitypub/type.js';
 import type { Response } from 'node-fetch';
 import type { URL } from 'node:url';
 
+export type HttpRequestSendOptions = {
+	throwErrorWhenResponseNotOk: boolean;
+	validators?: ((res: Response) => void)[];
+};
+
 @Injectable()
 export class HttpRequestService {
 	/**
@@ -105,6 +112,23 @@ export class HttpRequestService {
 	}
 
 	@bindThis
+	public async getActivityJson(url: string): Promise<IObject> {
+		const res = await this.send(url, {
+			method: 'GET',
+			headers: {
+				Accept: 'application/activity+json, application/ld+json; profile="https://www.w3.org/ns/activitystreams"',
+			},
+			timeout: 5000,
+			size: 1024 * 256,
+		}, {
+			throwErrorWhenResponseNotOk: true,
+			validators: [validateContentTypeSetAsActivityPub],
+		});
+
+		return await res.json() as IObject;
+	}
+
+	@bindThis
 	public async getJson<T = unknown>(url: string, accept = 'application/json, */*', headers?: Record<string, string>): Promise<T> {
 		const res = await this.send(url, {
 			method: 'GET',
@@ -132,17 +156,20 @@ export class HttpRequestService {
 	}
 
 	@bindThis
-	public async send(url: string, args: {
-		method?: string,
-		body?: string,
-		headers?: Record<string, string>,
-		timeout?: number,
-		size?: number,
-	} = {}, extra: {
-		throwErrorWhenResponseNotOk: boolean;
-	} = {
-		throwErrorWhenResponseNotOk: true,
-	}): Promise<Response> {
+	public async send(
+		url: string,
+		args: {
+			method?: string,
+			body?: string,
+			headers?: Record<string, string>,
+			timeout?: number,
+			size?: number,
+		} = {},
+		extra: HttpRequestSendOptions = {
+			throwErrorWhenResponseNotOk: true,
+			validators: [],
+		},
+	): Promise<Response> {
 		const timeout = args.timeout ?? 5000;
 
 		const controller = new AbortController();
@@ -166,6 +193,12 @@ export class HttpRequestService {
 			throw new StatusError(`${res.status} ${res.statusText}`, res.status, res.statusText);
 		}
 
+		if (res.ok) {
+			for (const validator of (extra.validators ?? [])) {
+				validator(res);
+			}
+		}
+
 		return res;
 	}
 }
diff --git a/packages/backend/src/core/activitypub/ApRequestService.ts b/packages/backend/src/core/activitypub/ApRequestService.ts
index 202e07814e..93ac8ce9a7 100644
--- a/packages/backend/src/core/activitypub/ApRequestService.ts
+++ b/packages/backend/src/core/activitypub/ApRequestService.ts
@@ -14,6 +14,7 @@ import { HttpRequestService } from '@/core/HttpRequestService.js';
 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';
 
 type Request = {
 	url: string;
@@ -70,7 +71,7 @@ export class ApRequestCreator {
 			url: u.href,
 			method: 'GET',
 			headers: this.#objectAssignWithLcKey({
-				'Accept': 'application/activity+json, application/ld+json',
+				'Accept': 'application/activity+json, application/ld+json; profile="https://www.w3.org/ns/activitystreams"',
 				'Date': new Date().toUTCString(),
 				'Host': new URL(args.url).host,
 			}, args.additionalHeaders),
@@ -195,6 +196,9 @@ export class ApRequestService {
 		const res = await this.httpRequestService.send(url, {
 			method: req.request.method,
 			headers: req.request.headers,
+		}, {
+			throwErrorWhenResponseNotOk: true,
+			validators: [validateContentTypeSetAsActivityPub],
 		});
 
 		return await res.json();
diff --git a/packages/backend/src/core/activitypub/ApResolverService.ts b/packages/backend/src/core/activitypub/ApResolverService.ts
index db44c042e7..bb3c40f093 100644
--- a/packages/backend/src/core/activitypub/ApResolverService.ts
+++ b/packages/backend/src/core/activitypub/ApResolverService.ts
@@ -105,7 +105,7 @@ export class Resolver {
 
 		const object = (this.user
 			? await this.apRequestService.signedGet(value, this.user) as IObject
-			: await this.httpRequestService.getJson(value, 'application/activity+json, application/ld+json')) as IObject;
+			: await this.httpRequestService.getActivityJson(value)) as IObject;
 
 		if (
 			Array.isArray(object['@context']) ?
diff --git a/packages/backend/src/core/activitypub/LdSignatureService.ts b/packages/backend/src/core/activitypub/LdSignatureService.ts
index f958e9d16e..9de184336f 100644
--- a/packages/backend/src/core/activitypub/LdSignatureService.ts
+++ b/packages/backend/src/core/activitypub/LdSignatureService.ts
@@ -8,6 +8,7 @@ import { Injectable } from '@nestjs/common';
 import { HttpRequestService } from '@/core/HttpRequestService.js';
 import { bindThis } from '@/decorators.js';
 import { CONTEXTS } from './misc/contexts.js';
+import { validateContentTypeSetAsJsonLD } from './misc/validator.js';
 import type { JsonLdDocument } from 'jsonld';
 import type { JsonLd, RemoteDocument } from 'jsonld/jsonld-spec.js';
 
@@ -133,7 +134,10 @@ class LdSignature {
 				},
 				timeout: this.loderTimeout,
 			},
-			{ throwErrorWhenResponseNotOk: false },
+			{
+				throwErrorWhenResponseNotOk: false,
+				validators: [validateContentTypeSetAsJsonLD],
+			},
 		).then(res => {
 			if (!res.ok) {
 				throw new Error(`${res.status} ${res.statusText}`);
diff --git a/packages/backend/src/core/activitypub/misc/validator.ts b/packages/backend/src/core/activitypub/misc/validator.ts
new file mode 100644
index 0000000000..6ba14a222f
--- /dev/null
+++ b/packages/backend/src/core/activitypub/misc/validator.ts
@@ -0,0 +1,39 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import type { Response } from 'node-fetch';
+
+export function validateContentTypeSetAsActivityPub(response: Response): void {
+	const contentType = (response.headers.get('content-type') ?? '').toLowerCase();
+
+	if (contentType === '') {
+		throw new Error('Validate content type of AP response: No content-type header');
+	}
+	if (
+		contentType.startsWith('application/activity+json') ||
+		(contentType.startsWith('application/ld+json;') && contentType.includes('https://www.w3.org/ns/activitystreams'))
+	) {
+		return;
+	}
+	throw new Error('Validate content type of AP response: Content type is not application/activity+json or application/ld+json');
+}
+
+const plusJsonSuffixRegex = /(application|text)\/[a-zA-Z0-9\.\-\+]+\+json/;
+
+export function validateContentTypeSetAsJsonLD(response: Response): void {
+	const contentType = (response.headers.get('content-type') ?? '').toLowerCase();
+
+	if (contentType === '') {
+		throw new Error('Validate content type of JSON LD: No content-type header');
+	}
+	if (
+		contentType.startsWith('application/ld+json') ||
+		contentType.startsWith('application/json') ||
+		plusJsonSuffixRegex.test(contentType)
+	) {
+		return;
+	}
+	throw new Error('Validate content type of JSON LD: Content type is not application/ld+json or application/json');
+}