fix: prevent hidden layers from being toggled in pdf viewers (#1528)

https://github.com/user-attachments/assets/e10194ca-212b-40ee-b9a1-85ef54829a40

---------

Co-authored-by: Mythie <me@lucasjamessmith.me>

packages/lib/server-only/document/seal-document.ts

@@ -6,8 +6,12 @@ import PostHogServerClient from '@documenso/lib/server-only/feature-flags/get-po
 import { DOCUMENT_AUDIT_LOG_TYPE } from '@documenso/lib/types/document-audit-logs';
 import { createDocumentAuditLogData } from '@documenso/lib/utils/document-audit-logs';
 import { prisma } from '@documenso/prisma';
-import { DocumentStatus, RecipientRole, SigningStatus } from '@documenso/prisma/client';
-import { WebhookTriggerEvents } from '@documenso/prisma/client';
+import {
+  DocumentStatus,
+  RecipientRole,
+  SigningStatus,
+  WebhookTriggerEvents,
+} from '@documenso/prisma/client';
 import { signPdf } from '@documenso/signing';
 
 import { ZWebhookDocumentSchema } from '../../types/webhook-payload';

packages/lib/server-only/document/send-document.tsx

@@ -9,8 +9,8 @@ import {
   RecipientRole,
   SendStatus,
   SigningStatus,
+  WebhookTriggerEvents,
 } from '@documenso/prisma/client';
-import { WebhookTriggerEvents } from '@documenso/prisma/client';
 
 import { jobs } from '../../jobs/client';
 import { extractDerivedDocumentEmailSettings } from '../../types/document-email';

packages/lib/server-only/pdf/flatten-form.ts

@@ -1,9 +1,11 @@
 import type { PDFField, PDFWidgetAnnotation } from 'pdf-lib';
-import { PDFCheckBox, PDFRadioGroup, PDFRef } from 'pdf-lib';
 import {
+  PDFCheckBox,
   PDFDict,
   type PDFDocument,
   PDFName,
+  PDFRadioGroup,
+  PDFRef,
   drawObject,
   popGraphicsState,
   pushGraphicsState,
@@ -11,7 +13,18 @@ import {
   translate,
 } from 'pdf-lib';
 
+export const removeOptionalContentGroups = (document: PDFDocument) => {
+  const context = document.context;
+  const catalog = context.lookup(context.trailerInfo.Root);
+
+  if (catalog instanceof PDFDict) {
+    catalog.delete(PDFName.of('OCProperties'));
+  }
+};
+
 export const flattenForm = (document: PDFDocument) => {
+  removeOptionalContentGroups(document);
+
   const form = document.getForm();
 
   form.updateFieldAppearances();

packages/lib/universal/upload/put-file.ts

@@ -8,6 +8,7 @@ import { DocumentDataType } from '@documenso/prisma/client';
 
 import { AppError } from '../../errors/app-error';
 import { createDocumentData } from '../../server-only/document-data/create-document-data';
+import { removeOptionalContentGroups } from '../../server-only/pdf/flatten-form';
 
 type File = {
   name: string;
@@ -24,20 +25,25 @@ export const putPdfFile = async (file: File) => {
     () => false,
   );
 
-  // This will prevent uploading encrypted PDFs or anything that can't be opened.
-  if (!isEncryptedDocumentsAllowed) {
-    await PDFDocument.load(await file.arrayBuffer()).catch((e) => {
+  const pdf = await PDFDocument.load(await file.arrayBuffer()).catch((e) => {
     console.error(`PDF upload parse error: ${e.message}`);
 
     throw new AppError('INVALID_DOCUMENT_FILE');
   });
+
+  if (!isEncryptedDocumentsAllowed && pdf.isEncrypted) {
+    throw new AppError('INVALID_DOCUMENT_FILE');
   }
 
   if (!file.name.endsWith('.pdf')) {
     file.name = `${file.name}.pdf`;
   }
 
-  const { type, data } = await putFile(file);
+  removeOptionalContentGroups(pdf);
+
+  const bytes = await pdf.save();
+
+  const { type, data } = await putFile(new File([bytes], file.name, { type: 'application/pdf' }));
 
   return await createDocumentData({ type, data });
 };