Pentest 62.7 LOW: deliveryDate / confirmationDate ISO-8601-Validierung

Bisher gingen XSS-Payloads in deliveryDate (saveEmailAsContractDocument,
saveAttachmentAsContractDocument, uploadContractDocument) und
confirmationDate (Cancellation-Confirmation-Upload) mit 200 durch.
Das Datum wurde silent als null behandelt; Impact gering, aber
schlechte API-Hygiene.

Neuer validateOptionalIsoDate-Helper in utils/sanitize:
- ISO-8601-Regex YYYY-MM-DD oder YYYY-MM-DDTHH:MM:SS(.fff)?(Z|+HH:MM)?
- null / leerer String / undefined sind OK (Optional-Semantik)
- Sonstige Eingaben werfen 400 mit klarer Meldung

Eingesetzt in:
- contract.controller uploadContractDocument (multer-Datei wird bei
  Reject sauber gelöscht)
- cachedEmail.controller saveEmailAsContractDocument +
  saveAttachmentAsContractDocument: Validierung früh, BEVOR Dateien
  geschrieben werden – kein Datei-Müll bei Reject
- upload.routes handleContractDocumentUpload (cancellationConfirmation*)

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

backend/src/controllers/cachedEmail.controller.ts

@@ -8,7 +8,7 @@ import { sendEmail, SmtpCredentials, SendEmailParams, EmailAttachment } from '..
 import { fetchAttachment, appendToSent, ImapCredentials } from '../services/imapService.js';
 import { getImapSmtpSettings } from '../services/emailProvider/emailProviderService.js';
 import { decrypt } from '../utils/encryption.js';
-import { sanitizeNotes, stripHtml, validateContractDocumentType } from '../utils/sanitize.js';
+import { sanitizeNotes, stripHtml, validateContractDocumentType, validateOptionalIsoDate } from '../utils/sanitize.js';
 import { logChange } from '../services/audit.service.js';
 import { ApiResponse, AuthRequest } from '../types/index.js';
 import { getCustomerTargets, getContractTargets, getIdentityDocumentTargets, getBankCardTargets, documentTargets } from '../config/documentTargets.config.js';
@@ -1836,6 +1836,15 @@ export async function saveEmailAsContractDocument(req: AuthRequest, res: Respons
       return;
     }
 
+    // Pentest 62.7: deliveryDate früh validieren, bevor wir Dateien schreiben.
+    let deliveryDate: string | null;
+    try {
+      deliveryDate = validateOptionalIsoDate(req.body?.deliveryDate, 'deliveryDate');
+    } catch (err) {
+      res.status(400).json({ success: false, error: err instanceof Error ? err.message : 'Ungültiges Lieferdatum' } as ApiResponse);
+      return;
+    }
+
     const email = await cachedEmailService.getCachedEmailById(emailId);
     if (!email) {
       res.status(404).json({ success: false, error: 'E-Mail nicht gefunden' } as ApiResponse);
@@ -1898,8 +1907,8 @@ export async function saveEmailAsContractDocument(req: AuthRequest, res: Respons
       });
     });
 
-    // Falls Lieferbestätigung: DRAFT → ACTIVE + startDate setzen falls leer
-    const deliveryDate = typeof req.body?.deliveryDate === 'string' ? req.body.deliveryDate : null;
+    // Falls Lieferbestätigung: DRAFT → ACTIVE + startDate setzen falls leer.
+    // deliveryDate wurde oben schon validiert (Pentest 62.7).
     await maybeActivateOnDeliveryConfirmation(contract.id, validatedType, req, deliveryDate);
 
     res.json({ success: true, data: doc } as ApiResponse);
@@ -2096,6 +2105,15 @@ export async function saveAttachmentAsContractDocument(req: AuthRequest, res: Re
       return;
     }
 
+    // Pentest 62.7: deliveryDate früh validieren, bevor wir Dateien schreiben.
+    let deliveryDate: string | null;
+    try {
+      deliveryDate = validateOptionalIsoDate(req.body?.deliveryDate, 'deliveryDate');
+    } catch (err) {
+      res.status(400).json({ success: false, error: err instanceof Error ? err.message : 'Ungültiges Lieferdatum' } as ApiResponse);
+      return;
+    }
+
     const email = await cachedEmailService.getCachedEmailById(emailId);
     if (!email) {
       res.status(404).json({ success: false, error: 'E-Mail nicht gefunden' } as ApiResponse);
@@ -2201,8 +2219,8 @@ export async function saveAttachmentAsContractDocument(req: AuthRequest, res: Re
       });
     });
 
-    // Falls Lieferbestätigung: DRAFT → ACTIVE + startDate setzen falls leer
-    const deliveryDate = typeof req.body?.deliveryDate === 'string' ? req.body.deliveryDate : null;
+    // Falls Lieferbestätigung: DRAFT → ACTIVE + startDate setzen falls leer.
+    // deliveryDate wurde oben schon validiert (Pentest 62.7).
     await maybeActivateOnDeliveryConfirmation(contract.id, validatedType, req, deliveryDate);
 
     res.json({ success: true, data: doc } as ApiResponse);

backend/src/controllers/contract.controller.ts

@@ -8,7 +8,7 @@ import * as authorizationService from '../services/authorization.service.js';
 import { recordPredecessorFinalReading } from '../services/customer.service.js';
 import { ApiResponse, AuthRequest } from '../types/index.js';
 import { logChange } from '../services/audit.service.js';
-import { sanitizeContract, sanitizeContractStrict, sanitizeContracts, sanitizeContractsStrict, stripHtml, sanitizeNotes, validateContractDocumentType } from '../utils/sanitize.js';
+import { sanitizeContract, sanitizeContractStrict, sanitizeContracts, sanitizeContractsStrict, stripHtml, sanitizeNotes, validateContractDocumentType, validateOptionalIsoDate } from '../utils/sanitize.js';
 import { canAccessContract } from '../utils/accessControl.js';
 import { maybeActivateOnDeliveryConfirmation, withContractDocumentLock } from '../services/contractStatusScheduler.service.js';
 
@@ -722,7 +722,7 @@ export async function uploadContractDocument(req: AuthRequest, res: Response): P
   try {
     const contractId = parseInt(req.params.id);
     if (!(await canAccessContract(req, res, contractId))) return;
-    const { documentType, notes, deliveryDate } = req.body;
+    const { documentType, notes } = req.body;
 
     if (!req.file) {
       res.status(400).json({ success: false, error: 'Keine Datei hochgeladen' } as ApiResponse);
@@ -734,6 +734,16 @@ export async function uploadContractDocument(req: AuthRequest, res: Response): P
       return;
     }
 
+    // Pentest 62.7: deliveryDate validieren (ISO-8601 oder null).
+    let deliveryDate: string | null;
+    try {
+      deliveryDate = validateOptionalIsoDate(req.body?.deliveryDate, 'deliveryDate');
+    } catch (err) {
+      try { fs.unlinkSync(req.file.path); } catch { /* ignore */ }
+      res.status(400).json({ success: false, error: err instanceof Error ? err.message : 'Ungültiges Lieferdatum' } as ApiResponse);
+      return;
+    }
+
     const documentPath = `/uploads/contract-documents/${req.file.filename}`;
     // Pentest 58.1: Whitelist-Validierung statt nur stripHtml. Multer hat
     // die Datei schon geschrieben – bei Reject räumen wir sie wieder weg.