feat: improve share security

backend/src/share/guard/shareTokenSecurity.guard.ts

@@ -0,0 +1,47 @@
+import {
+  CanActivate,
+  ExecutionContext,
+  ForbiddenException,
+  Injectable,
+  NotFoundException,
+} from "@nestjs/common";
+import { Reflector } from "@nestjs/core";
+import { Request } from "express";
+import * as moment from "moment";
+import { PrismaService } from "src/prisma/prisma.service";
+import { ShareService } from "src/share/share.service";
+
+@Injectable()
+export class ShareTokenSecurity implements CanActivate {
+  constructor(
+    private reflector: Reflector,
+    private shareService: ShareService,
+    private prisma: PrismaService
+  ) {}
+
+  async canActivate(context: ExecutionContext) {
+    const request: Request = context.switchToHttp().getRequest();
+    const shareId = Object.prototype.hasOwnProperty.call(
+      request.params,
+      "shareId"
+    )
+      ? request.params.shareId
+      : request.params.id;
+
+    const share = await this.prisma.share.findUnique({
+      where: { id: shareId },
+      include: { security: true },
+    });
+
+    if (!share || moment().isAfter(share.expiration))
+      throw new NotFoundException("Share not found");
+
+    if (share.security?.maxViews && share.security.maxViews <= share.views)
+      throw new ForbiddenException(
+        "Maximum views exceeded",
+        "share_max_views_exceeded"
+      );
+
+    return true;
+  }
+}