Security-Hardening Runde 10: Pentest Runde 6 (8 Findings + struktureller Audit-Sweep)

KRITISCH:
- emails/:id/thread bekommt canAccessCachedEmail
- customers/:customerId/representatives/search bekommt canAccessCustomer
  (Buchstaben-Brute-Force konnte sonst die Kunden-DB enumerieren)

HOCH:
- birthdays/upcoming: Portal-User → 403 (Name/E-Mail/Telefon/Geb-Datum
  aller Kunden leakte)
- contracts/:id/history (GET/POST/PUT/DELETE) bekommt canAccessContract
- mailbox-accounts / unread-count / contracts/:id/emails/folder-counts
  bekommen canAccessCustomer bzw. canAccessContract
- Vertreter-Vollmacht-Check ist jetzt live: neuer Helper
  getPortalAllowedCustomerIds() in accessControl.ts ruft
  hasAuthorization() für jedes vertretene Customer ab. Eingesetzt in
  getTasks/createSupportTicket/createCustomerReply/getAllTasks/
  getTaskStats und updateCustomerConsent. Widerrufene Vollmachten
  haben jetzt SOFORT keinen Zugriff mehr (vorher: bis JWT abläuft).

MITTEL:
- confirmPasswordReset speichert portalPasswordEncrypted nicht mehr
  beim Self-Service-Reset (war nur für Admin-OTPs gedacht); +
  portalPasswordMustChange=false explizit
- getCustomers pagination total reflektiert jetzt nur erlaubte IDs
  (über DB-Filter in customerService.getAllCustomers)

Audit-Sweep (defense in depth, falls Rolle versehentlich Update-
Permissions bekommt):
- 16 cachedEmail-Operationen (markAsRead, toggleStar, assign/unassign,
  save-as-pdf/invoice/contract-document, save-to, attachment-targets,
  trash-ops)
- 4 contract-Operationen (createFollowUp, createRenewal, snoozeContract,
  removeContractMeter)
- 12 sub-CRUD-Operationen (address/bankcard/document/meter
  update+delete, meter-reading add/update/delete/transfer)
- 2 representative-Operationen (add/remove)

Live-verifiziert: Portal-Customer-3 auf alle fremden IDs → 403,
Admin sieht alles, eigene Ressourcen weiterhin 200, Customer 1 mit
widerrufener Vollmacht für Customer 3 → 0 fremde Verträge in der
Response.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/src/controllers/contractHistory.controller.ts

@@ -2,10 +2,12 @@ import { Request, Response } from 'express';
 import * as contractHistoryService from '../services/contractHistory.service.js';
 import { logChange } from '../services/audit.service.js';
 import { ApiResponse, AuthRequest } from '../types/index.js';
+import { canAccessContract } from '../utils/accessControl.js';
 
 export async function getHistoryEntries(req: AuthRequest, res: Response): Promise<void> {
   try {
     const contractId = parseInt(req.params.contractId);
+    if (!(await canAccessContract(req, res, contractId))) return;
     const entries = await contractHistoryService.getHistoryEntries(contractId);
     res.json({ success: true, data: entries } as ApiResponse);
   } catch (error) {
@@ -19,6 +21,7 @@ export async function getHistoryEntries(req: AuthRequest, res: Response): Promis
 export async function createHistoryEntry(req: AuthRequest, res: Response): Promise<void> {
   try {
     const contractId = parseInt(req.params.contractId);
+    if (!(await canAccessContract(req, res, contractId))) return;
     const { title, description } = req.body;
 
     if (!title || typeof title !== 'string' || title.trim().length === 0) {
@@ -54,6 +57,7 @@ export async function createHistoryEntry(req: AuthRequest, res: Response): Promi
 export async function updateHistoryEntry(req: AuthRequest, res: Response): Promise<void> {
   try {
     const contractId = parseInt(req.params.contractId);
+    if (!(await canAccessContract(req, res, contractId))) return;
     const entryId = parseInt(req.params.entryId);
     const { title, description } = req.body;
 
@@ -80,6 +84,7 @@ export async function updateHistoryEntry(req: AuthRequest, res: Response): Promi
 export async function deleteHistoryEntry(req: AuthRequest, res: Response): Promise<void> {
   try {
     const contractId = parseInt(req.params.contractId);
+    if (!(await canAccessContract(req, res, contractId))) return;
     const entryId = parseInt(req.params.entryId);
 
     await contractHistoryService.deleteHistoryEntry(contractId, entryId);