fix(gateway): security hardening — auth guards, ownership checks, validation, rate limiting

apps/gateway/src/tasks/tasks.controller.ts

@@ -2,6 +2,7 @@ import {
   Body,
   Controller,
   Delete,
+  ForbiddenException,
   Get,
   HttpCode,
   HttpStatus,
@@ -16,7 +17,9 @@ import {
 import type { Brain } from '@mosaic/brain';
 import { BRAIN } from '../brain/brain.tokens.js';
 import { AuthGuard } from '../auth/auth.guard.js';
-import type { CreateTaskDto, UpdateTaskDto } from './tasks.dto.js';
+import { CurrentUser } from '../auth/current-user.decorator.js';
+import { assertOwner } from '../auth/resource-ownership.js';
+import { CreateTaskDto, UpdateTaskDto } from './tasks.dto.js';
 
 @Controller('api/tasks')
 @UseGuards(AuthGuard)
@@ -39,10 +42,8 @@ export class TasksController {
   }
 
   @Get(':id')
-  async findOne(@Param('id') id: string) {
-    const task = await this.brain.tasks.findById(id);
-    if (!task) throw new NotFoundException('Task not found');
-    return task;
+  async findOne(@Param('id') id: string, @CurrentUser() user: { id: string }) {
+    return this.getOwnedTask(id, user.id);
   }
 
   @Post()
@@ -61,7 +62,18 @@ export class TasksController {
   }
 
   @Patch(':id')
-  async update(@Param('id') id: string, @Body() dto: UpdateTaskDto) {
+  async update(
+    @Param('id') id: string,
+    @Body() dto: UpdateTaskDto,
+    @CurrentUser() user: { id: string },
+  ) {
+    await this.getOwnedTask(id, user.id);
+    if (dto.projectId) {
+      await this.getOwnedProject(dto.projectId, user.id, 'Task');
+    }
+    if (dto.missionId) {
+      await this.getOwnedMission(dto.missionId, user.id, 'Task');
+    }
     const task = await this.brain.tasks.update(id, {
       ...dto,
       dueDate: dto.dueDate ? new Date(dto.dueDate) : dto.dueDate === null ? null : undefined,
@@ -72,8 +84,46 @@ export class TasksController {
 
   @Delete(':id')
   @HttpCode(HttpStatus.NO_CONTENT)
-  async remove(@Param('id') id: string) {
+  async remove(@Param('id') id: string, @CurrentUser() user: { id: string }) {
+    await this.getOwnedTask(id, user.id);
     const deleted = await this.brain.tasks.remove(id);
     if (!deleted) throw new NotFoundException('Task not found');
   }
+
+  private async getOwnedTask(id: string, userId: string) {
+    const task = await this.brain.tasks.findById(id);
+    if (!task) throw new NotFoundException('Task not found');
+
+    if (task.projectId) {
+      await this.getOwnedProject(task.projectId, userId, 'Task');
+      return task;
+    }
+
+    if (task.missionId) {
+      await this.getOwnedMission(task.missionId, userId, 'Task');
+      return task;
+    }
+
+    throw new ForbiddenException('Task does not belong to the current user');
+  }
+
+  private async getOwnedMission(missionId: string, userId: string, resourceName: string) {
+    const mission = await this.brain.missions.findById(missionId);
+    if (!mission?.projectId) {
+      throw new ForbiddenException(`${resourceName} does not belong to the current user`);
+    }
+
+    await this.getOwnedProject(mission.projectId, userId, resourceName);
+    return mission;
+  }
+
+  private async getOwnedProject(projectId: string, userId: string, resourceName: string) {
+    const project = await this.brain.projects.findById(projectId);
+    if (!project) {
+      throw new ForbiddenException(`${resourceName} does not belong to the current user`);
+    }
+
+    assertOwner(project.ownerId, userId, resourceName);
+    return project;
+  }
 }

apps/gateway/src/tasks/tasks.dto.ts

@@ -1,24 +1,103 @@
-export interface CreateTaskDto {
-  title: string;
+import {
+  ArrayMaxSize,
+  IsArray,
+  IsIn,
+  IsISO8601,
+  IsObject,
+  IsOptional,
+  IsString,
+  IsUUID,
+  MaxLength,
+} from 'class-validator';
+
+const taskStatuses = ['not-started', 'in-progress', 'blocked', 'done', 'cancelled'] as const;
+const taskPriorities = ['critical', 'high', 'medium', 'low'] as const;
+
+export class CreateTaskDto {
+  @IsString()
+  @MaxLength(255)
+  title!: string;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(10_000)
   description?: string;
+
+  @IsOptional()
+  @IsIn(taskStatuses)
   status?: 'not-started' | 'in-progress' | 'blocked' | 'done' | 'cancelled';
+
+  @IsOptional()
+  @IsIn(taskPriorities)
   priority?: 'critical' | 'high' | 'medium' | 'low';
+
+  @IsOptional()
+  @IsUUID()
   projectId?: string;
+
+  @IsOptional()
+  @IsUUID()
   missionId?: string;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(255)
   assignee?: string;
+
+  @IsOptional()
+  @IsArray()
+  @ArrayMaxSize(50)
+  @IsString({ each: true })
   tags?: string[];
+
+  @IsOptional()
+  @IsISO8601()
   dueDate?: string;
 }
 
-export interface UpdateTaskDto {
+export class UpdateTaskDto {
+  @IsOptional()
+  @IsString()
+  @MaxLength(255)
   title?: string;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(10_000)
   description?: string | null;
+
+  @IsOptional()
+  @IsIn(taskStatuses)
   status?: 'not-started' | 'in-progress' | 'blocked' | 'done' | 'cancelled';
+
+  @IsOptional()
+  @IsIn(taskPriorities)
   priority?: 'critical' | 'high' | 'medium' | 'low';
+
+  @IsOptional()
+  @IsUUID()
   projectId?: string | null;
+
+  @IsOptional()
+  @IsUUID()
   missionId?: string | null;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(255)
   assignee?: string | null;
+
+  @IsOptional()
+  @IsArray()
+  @ArrayMaxSize(50)
+  @IsString({ each: true })
   tags?: string[] | null;
+
+  @IsOptional()
+  @IsISO8601()
   dueDate?: string | null;
+
+  @IsOptional()
+  @IsObject()
   metadata?: Record<string, unknown> | null;
 }