Use unique identifier for each follow request (#10600)

Co-authored-by: anemone <anemoneya@icloud.com>

packages/backend/src/core/UserFollowingService.ts

@@ -20,6 +20,7 @@ import { bindThis } from '@/decorators.js';
 import { UserBlockingService } from '@/core/UserBlockingService.js';
 import { MetaService } from '@/core/MetaService.js';
 import { CacheService } from '@/core/CacheService.js';
+import type { Config } from '@/config.js';
 import Logger from '../logger.js';
 
 const logger = new Logger('following/create');
@@ -44,6 +45,9 @@ export class UserFollowingService implements OnModuleInit {
 	constructor(
 		private moduleRef: ModuleRef,
 
+		@Inject(DI.config)
+		private config: Config,
+
 		@Inject(DI.usersRepository)
 		private usersRepository: UsersRepository,
 
@@ -411,7 +415,7 @@ export class UserFollowingService implements OnModuleInit {
 		}
 
 		if (this.userEntityService.isLocalUser(follower) && this.userEntityService.isRemoteUser(followee)) {
-			const content = this.apRendererService.addContext(this.apRendererService.renderFollow(follower, followee));
+			const content = this.apRendererService.addContext(this.apRendererService.renderFollow(follower, followee, requestId ?? `${this.config.url}/follows/${followRequest.id}`));
 			this.queueService.deliver(follower, content, followee.inbox, false);
 		}
 	}

packages/backend/src/server/ActivityPubServerService.ts

@@ -6,7 +6,7 @@ import { Brackets, In, IsNull, LessThan, Not } from 'typeorm';
 import accepts from 'accepts';
 import vary from 'vary';
 import { DI } from '@/di-symbols.js';
-import type { FollowingsRepository, NotesRepository, EmojisRepository, NoteReactionsRepository, UserProfilesRepository, UserNotePiningsRepository, UsersRepository } from '@/models/index.js';
+import type { FollowingsRepository, NotesRepository, EmojisRepository, NoteReactionsRepository, UserProfilesRepository, UserNotePiningsRepository, UsersRepository, FollowRequestsRepository } from '@/models/index.js';
 import * as url from '@/misc/prelude/url.js';
 import type { Config } from '@/config.js';
 import { ApRendererService } from '@/core/activitypub/ApRendererService.js';
@@ -54,6 +54,9 @@ export class ActivityPubServerService {
 		@Inject(DI.followingsRepository)
 		private followingsRepository: FollowingsRepository,
 
+		@Inject(DI.followRequestsRepository)
+		private followRequestsRepository: FollowRequestsRepository,
+
 		private utilityService: UtilityService,
 		private userEntityService: UserEntityService,
 		private apRendererService: ApRendererService,
@@ -639,6 +642,41 @@ export class ActivityPubServerService {
 			return (this.apRendererService.addContext(this.apRendererService.renderFollow(follower, followee)));
 		});
 
+		// follow
+		fastify.get<{ Params: { followRequestId: string ; } }>('/follows/:followRequestId', async (request, reply) => {
+			// This may be used before the follow is completed, so we do not
+			// check if the following exists and only check if the follow request exists.
+
+			const followRequest = await this.followRequestsRepository.findOneBy({
+				id: request.params.followRequestId,
+			});
+
+			if (followRequest == null) {
+				reply.code(404);
+				return;
+			}
+
+			const [follower, followee] = await Promise.all([
+				this.usersRepository.findOneBy({
+					id: followRequest.followerId,
+					host: IsNull(),
+				}),
+				this.usersRepository.findOneBy({
+					id: followRequest.followeeId,
+					host: Not(IsNull()),
+				}),
+			]);
+
+			if (follower == null || followee == null) {
+				reply.code(404);
+				return;
+			}
+
+			reply.header('Cache-Control', 'public, max-age=180');
+			this.setResponseType(request, reply);
+			return (this.apRendererService.addContext(this.apRendererService.renderFollow(follower, followee)));
+		});
+
 		done();
 	}
 }