chore: use rust based cms signing

packages/signing/helpers/add-signing-placeholder.ts

@@ -1,4 +1,3 @@
-import signer from 'node-signpdf';
 import {
   PDFArray,
   PDFDocument,
@@ -9,6 +8,8 @@ import {
   rectangle,
 } from 'pdf-lib';
 
+import { BYTE_RANGE_PLACEHOLDER } from '../constants/byte-range';
+
 export type AddSigningPlaceholderOptions = {
   pdf: Buffer;
 };
@@ -20,9 +21,9 @@ export const addSigningPlaceholder = async ({ pdf }: AddSigningPlaceholderOption
   const byteRange = PDFArray.withContext(doc.context);
 
   byteRange.push(PDFNumber.of(0));
-  byteRange.push(PDFName.of(signer.byteRangePlaceholder));
-  byteRange.push(PDFName.of(signer.byteRangePlaceholder));
-  byteRange.push(PDFName.of(signer.byteRangePlaceholder));
+  byteRange.push(PDFName.of(BYTE_RANGE_PLACEHOLDER));
+  byteRange.push(PDFName.of(BYTE_RANGE_PLACEHOLDER));
+  byteRange.push(PDFName.of(BYTE_RANGE_PLACEHOLDER));
 
   const signature = doc.context.obj({
     Type: 'Sig',

packages/signing/helpers/update-signing-placeholder.test.ts

@@ -0,0 +1,72 @@
+import { describe, expect, it } from 'vitest';
+
+import { updateSigningPlaceholder } from './update-signing-placeholder';
+
+describe('updateSigningPlaceholder', () => {
+  const pdf = Buffer.from(`
+      20 0 obj
+      <<
+      /Type /Sig
+      /Filter /Adobe.PPKLite
+      /SubFilter /adbe.pkcs7.detached
+      /ByteRange [ 0 /********** /********** /********** ]
+      /Contents <0000000000000000000000000000000000000000000000000000000>
+      /Reason (Signed by Documenso)
+      /M (D:20210101000000Z)
+      >>
+      endobj
+    `);
+
+  it('should not throw an error', () => {
+      expect(() => updateSigningPlaceholder({ pdf })).not.toThrowError();
+  });
+
+  it('should not modify the original PDF', () => {
+    const result = updateSigningPlaceholder({ pdf });
+
+    expect(result.pdf).not.toEqual(pdf);
+  });
+
+  it('should return a PDF with the same length as the original', () => {
+    const result = updateSigningPlaceholder({ pdf });
+
+    expect(result.pdf).toHaveLength(pdf.length);
+  });
+
+  it('should update the byte range and return it', () => {
+    const result = updateSigningPlaceholder({ pdf });
+
+    expect(result.byteRange).toEqual([0, 184, 241, 92]);
+  });
+
+  it('should only update the last signature in the PDF', () => {
+    const pdf = Buffer.from(`
+      20 0 obj
+      <<
+      /Type /Sig
+      /Filter /Adobe.PPKLite
+      /SubFilter /adbe.pkcs7.detached
+      /ByteRange [ 0 /********** /********** /********** ]
+      /Contents <0000000000000000000000000000000000000000000000000000000>
+      /Reason (Signed by Documenso)
+      /M (D:20210101000000Z)
+      >>
+      endobj
+      21 0 obj
+      <<
+      /Type /Sig
+      /Filter /Adobe.PPKLite
+      /SubFilter /adbe.pkcs7.detached
+      /ByteRange [ 0 /********** /********** /********** ]
+      /Contents <0000000000000000000000000000000000000000000000000000000>
+      /Reason (Signed by Documenso)
+      /M (D:20210101000000Z)
+      >>
+      endobj
+    `);
+
+    const result = updateSigningPlaceholder({ pdf });
+
+    expect(result.byteRange).toEqual([0, 512, 569, 92]);
+  });
+});

packages/signing/helpers/update-signing-placeholder.ts

@@ -0,0 +1,39 @@
+export type UpdateSigningPlaceholderOptions = {
+  pdf: Buffer;
+};
+
+export const updateSigningPlaceholder = ({ pdf }: UpdateSigningPlaceholderOptions) => {
+  const length = pdf.length;
+
+  const byteRangePos = pdf.lastIndexOf('/ByteRange');
+  const byteRangeStart = pdf.indexOf('[', byteRangePos);
+  const byteRangeEnd = pdf.indexOf(']', byteRangePos);
+
+  const byteRangeSlice = pdf.subarray(byteRangeStart, byteRangeEnd + 1);
+
+  const signaturePos = pdf.indexOf('/Contents', byteRangeEnd);
+  const signatureStart = pdf.indexOf('<', signaturePos);
+  const signatureEnd = pdf.indexOf('>', signaturePos);
+
+  const signatureSlice = pdf.subarray(signatureStart, signatureEnd + 1);
+
+  const byteRange = [0, 0, 0, 0];
+
+  byteRange[1] = signatureStart;
+  byteRange[2] = byteRange[1] + signatureSlice.length;
+  byteRange[3] = length - byteRange[2];
+
+  const newByteRange = `[${byteRange.join(' ')}]`.padEnd(byteRangeSlice.length, ' ');
+
+  const updatedPdf = Buffer.concat([
+    pdf.subarray(0, byteRangeStart),
+    Buffer.from(newByteRange),
+    pdf.subarray(byteRangeEnd + 1),
+  ]);
+
+  if (updatedPdf.length !== length) {
+    throw new Error('Updated PDF length does not match original length');
+  }
+
+  return { pdf: updatedPdf, byteRange };
+};