refactor pdf decrypt

src/js/logic/decrypt-pdf-page.ts

@@ -2,9 +2,9 @@ import { showAlert } from '../ui.js';
 import {
   downloadFile,
   formatBytes,
-  initializeQpdf,
   readFileAsArrayBuffer,
 } from '../utils/helpers.js';
+import { decryptPdfBytes } from '../utils/pdf-decrypt.js';
 import { icons, createIcons } from 'lucide';
 import JSZip from 'jszip';
 import { DecryptPdfState } from '@/types';
@@ -115,79 +115,39 @@ async function decryptPdf() {
 
   const loaderModal = document.getElementById('loader-modal');
   const loaderText = document.getElementById('loader-text');
-  let qpdf: any;
 
   try {
     if (loaderModal) loaderModal.classList.remove('hidden');
     if (loaderText) loaderText.textContent = 'Initializing decryption...';
 
-    qpdf = await initializeQpdf();
-
     if (pageState.files.length === 1) {
       // Single file: decrypt and download directly
       const file = pageState.files[0];
-      const inputPath = '/input.pdf';
-      const outputPath = '/output.pdf';
+      if (loaderText) loaderText.textContent = 'Reading encrypted PDF...';
+      const fileBuffer = await readFileAsArrayBuffer(file);
+      const uint8Array = new Uint8Array(fileBuffer as ArrayBuffer);
 
-      try {
-        if (loaderText) loaderText.textContent = 'Reading encrypted PDF...';
-        const fileBuffer = await readFileAsArrayBuffer(file);
-        const uint8Array = new Uint8Array(fileBuffer as ArrayBuffer);
-        qpdf.FS.writeFile(inputPath, uint8Array);
+      if (loaderText) loaderText.textContent = 'Decrypting PDF...';
+      const { bytes: decryptedBytes } = await decryptPdfBytes(
+        uint8Array,
+        password
+      );
 
-        if (loaderText) loaderText.textContent = 'Decrypting PDF...';
-        const args = [
-          inputPath,
-          '--password=' + password,
-          '--decrypt',
-          outputPath,
-        ];
+      if (loaderText) loaderText.textContent = 'Preparing download...';
+      const blob = new Blob([decryptedBytes.slice().buffer], {
+        type: 'application/pdf',
+      });
+      downloadFile(blob, `unlocked-${file.name}`);
 
-        try {
-          qpdf.callMain(args);
-        } catch (qpdfError: any) {
-          if (
-            qpdfError.message?.includes('invalid password') ||
-            qpdfError.message?.includes('password')
-          ) {
-            throw new Error('INVALID_PASSWORD');
-          }
-          throw qpdfError;
+      if (loaderModal) loaderModal.classList.add('hidden');
+      showAlert(
+        'Success',
+        'PDF decrypted successfully! Your download has started.',
+        'success',
+        () => {
+          resetState();
         }
-
-        if (loaderText) loaderText.textContent = 'Preparing download...';
-        const outputFile = qpdf.FS.readFile(outputPath, { encoding: 'binary' });
-
-        if (outputFile.length === 0) {
-          throw new Error('Decryption resulted in an empty file.');
-        }
-
-        const blob = new Blob([new Uint8Array(outputFile)], {
-          type: 'application/pdf',
-        });
-        downloadFile(blob, `unlocked-${file.name}`);
-
-        if (loaderModal) loaderModal.classList.add('hidden');
-        showAlert(
-          'Success',
-          'PDF decrypted successfully! Your download has started.',
-          'success',
-          () => {
-            resetState();
-          }
-        );
-      } finally {
-        try {
-          if (qpdf?.FS) {
-            if (qpdf.FS.analyzePath(inputPath).exists)
-              qpdf.FS.unlink(inputPath);
-            if (qpdf.FS.analyzePath(outputPath).exists)
-              qpdf.FS.unlink(outputPath);
-          }
-        } catch (cleanupError) {
-          console.warn('Failed to cleanup WASM FS:', cleanupError);
-        }
-      }
+      );
     } else {
       // Multiple files: decrypt all and download as ZIP
       const zip = new JSZip();
@@ -196,8 +156,6 @@ async function decryptPdf() {
 
       for (let i = 0; i < pageState.files.length; i++) {
         const file = pageState.files[i];
-        const inputPath = `/input_${i}.pdf`;
-        const outputPath = `/output_${i}.pdf`;
 
         if (loaderText)
           loaderText.textContent = `Decrypting ${file.name} (${i + 1}/${pageState.files.length})...`;
@@ -205,55 +163,16 @@ async function decryptPdf() {
         try {
           const fileBuffer = await readFileAsArrayBuffer(file);
           const uint8Array = new Uint8Array(fileBuffer as ArrayBuffer);
-          qpdf.FS.writeFile(inputPath, uint8Array);
+          const { bytes: decryptedBytes } = await decryptPdfBytes(
+            uint8Array,
+            password
+          );
 
-          const args = [
-            inputPath,
-            '--password=' + password,
-            '--decrypt',
-            outputPath,
-          ];
-
-          try {
-            qpdf.callMain(args);
-          } catch (qpdfError: any) {
-            if (
-              qpdfError.message?.includes('invalid password') ||
-              qpdfError.message?.includes('password')
-            ) {
-              throw new Error(`Invalid password for ${file.name}`);
-            }
-            throw qpdfError;
-          }
-
-          const outputFile = qpdf.FS.readFile(outputPath, {
-            encoding: 'binary',
-          });
-          if (!outputFile || outputFile.length === 0) {
-            throw new Error(
-              `Decryption resulted in an empty file for ${file.name}.`
-            );
-          }
-
-          zip.file(`unlocked-${file.name}`, outputFile, { binary: true });
+          zip.file(`unlocked-${file.name}`, decryptedBytes, { binary: true });
           successCount++;
         } catch (fileError: any) {
           errorCount++;
           console.error(`Failed to decrypt ${file.name}:`, fileError);
-        } finally {
-          try {
-            if (qpdf?.FS) {
-              if (qpdf.FS.analyzePath(inputPath).exists)
-                qpdf.FS.unlink(inputPath);
-              if (qpdf.FS.analyzePath(outputPath).exists)
-                qpdf.FS.unlink(outputPath);
-            }
-          } catch (cleanupError) {
-            console.warn(
-              `Failed to cleanup WASM FS for ${file.name}:`,
-              cleanupError
-            );
-          }
         }
       }
 

src/js/utils/pdf-decrypt.ts

@@ -0,0 +1,172 @@
+import { getCpdf, isCpdfAvailable } from './cpdf-helper';
+import { isPyMuPDFAvailable, loadPyMuPDF } from './pymupdf-loader';
+
+export type PdfDecryptEngine = 'cpdf' | 'pymupdf';
+
+export interface PdfDecryptResult {
+  bytes: Uint8Array;
+  engine: PdfDecryptEngine;
+}
+
+const DECRYPT_LOG_PREFIX = '[PDF Decrypt]';
+
+function getErrorMessage(error: unknown): string {
+  if (error instanceof Error && error.message) {
+    return error.message;
+  }
+
+  return String(error);
+}
+
+function normalizeErrorMessage(error: unknown): string {
+  const message = getErrorMessage(error).trim();
+  const cpdfReasonMatch = message.match(/Pdf\.PDFError\("([^"]+)"\)/);
+  if (cpdfReasonMatch?.[1]) {
+    return cpdfReasonMatch[1];
+  }
+
+  const trailingErrorMatch = message.match(/ERROR:\s*[^:]+:\s*(.+)$/);
+  if (trailingErrorMatch?.[1]) {
+    return trailingErrorMatch[1].trim();
+  }
+
+  return message;
+}
+
+function copyBytes(bytes: Uint8Array): Uint8Array {
+  return Uint8Array.from(bytes);
+}
+
+function cleanupCpdfDocument(cpdf: unknown, pdf: unknown): void {
+  if (!cpdf || !pdf || typeof cpdf !== 'object' || !('deletePdf' in cpdf)) {
+    return;
+  }
+
+  try {
+    (cpdf as { deletePdf: (document: unknown) => void }).deletePdf(pdf);
+  } catch (cleanupError) {
+    console.warn(
+      `${DECRYPT_LOG_PREFIX} Failed to cleanup CoherentPDF document: ${normalizeErrorMessage(cleanupError)}`
+    );
+  }
+}
+
+async function decryptWithCpdf(
+  inputBytes: Uint8Array,
+  password: string
+): Promise<Uint8Array> {
+  const cpdf = await getCpdf();
+  cpdf.setSlow();
+
+  let pdf: unknown | null = null;
+
+  try {
+    pdf = cpdf.fromMemory(new Uint8Array(inputBytes), password);
+
+    if (cpdf.isEncrypted(pdf)) {
+      try {
+        cpdf.decryptPdf(pdf, password);
+      } catch {
+        cpdf.decryptPdfOwner(pdf, password);
+      }
+    }
+
+    const outputBytes = cpdf.toMemory(pdf, false, false);
+    pdf = null;
+
+    if (!(outputBytes instanceof Uint8Array) || outputBytes.length === 0) {
+      throw new Error('CoherentPDF produced an empty decrypted file.');
+    }
+
+    return copyBytes(outputBytes);
+  } catch (error) {
+    if (pdf) {
+      cleanupCpdfDocument(cpdf, pdf);
+    }
+
+    throw new Error(normalizeErrorMessage(error), { cause: error });
+  }
+}
+
+async function decryptWithPyMuPDF(
+  inputBytes: Uint8Array,
+  password: string
+): Promise<Uint8Array> {
+  const pymupdf = await loadPyMuPDF();
+  const document = await pymupdf.open(
+    new Blob([new Uint8Array(inputBytes)], { type: 'application/pdf' })
+  );
+
+  try {
+    if (document.needsPass || document.isEncrypted) {
+      const authenticated = document.authenticate(password);
+      if (!authenticated) {
+        throw new Error('Invalid PDF password.');
+      }
+    }
+
+    const outputBytes = document.save();
+    if (!(outputBytes instanceof Uint8Array) || outputBytes.length === 0) {
+      throw new Error('PyMuPDF produced an empty decrypted file.');
+    }
+
+    return copyBytes(outputBytes);
+  } finally {
+    document.close();
+  }
+}
+
+export async function decryptPdfBytes(
+  inputBytes: Uint8Array,
+  password: string
+): Promise<PdfDecryptResult> {
+  const errors: string[] = [];
+
+  if (isCpdfAvailable()) {
+    console.info(`${DECRYPT_LOG_PREFIX} Trying CoherentPDF decryption`);
+    try {
+      const result: PdfDecryptResult = {
+        bytes: await decryptWithCpdf(inputBytes, password),
+        engine: 'cpdf',
+      };
+      console.info(
+        `${DECRYPT_LOG_PREFIX} Decryption succeeded with CoherentPDF`
+      );
+      return result;
+    } catch (error) {
+      const errorMessage = normalizeErrorMessage(error);
+      console.warn(
+        `${DECRYPT_LOG_PREFIX} Decryption with CoherentPDF failed. Falling back to PyMuPDF. Reason: ${errorMessage}`
+      );
+      errors.push(`CoherentPDF: ${errorMessage}`);
+    }
+  } else {
+    console.info(
+      `${DECRYPT_LOG_PREFIX} CoherentPDF is not configured, skipping to PyMuPDF`
+    );
+    errors.push('CoherentPDF: not configured.');
+  }
+
+  if (isPyMuPDFAvailable()) {
+    console.info(`${DECRYPT_LOG_PREFIX} Trying PyMuPDF decryption`);
+    try {
+      const result: PdfDecryptResult = {
+        bytes: await decryptWithPyMuPDF(inputBytes, password),
+        engine: 'pymupdf',
+      };
+      console.info(`${DECRYPT_LOG_PREFIX} Decryption succeeded with PyMuPDF`);
+      return result;
+    } catch (error) {
+      const errorMessage = normalizeErrorMessage(error);
+      console.warn(
+        `${DECRYPT_LOG_PREFIX} PyMuPDF decryption failed: ${errorMessage}`
+      );
+      errors.push(`PyMuPDF: ${errorMessage}`);
+    }
+  } else {
+    console.warn(`${DECRYPT_LOG_PREFIX} PyMuPDF is not configured`);
+    errors.push('PyMuPDF: not configured.');
+  }
+
+  throw new Error(errors.join('\n'));
+}

src/js/workflow/nodes/decrypt-node.ts

@@ -4,7 +4,7 @@ import { pdfSocket } from '../sockets';
 import type { SocketData } from '../types';
 import { requirePdfInput, processBatch } from '../types';
 import { PDFDocument } from 'pdf-lib';
-import { initializeQpdf } from '../../utils/helpers.js';
+import { decryptPdfBytes } from '../../utils/pdf-decrypt.js';
 
 export class DecryptNode extends BaseWorkflowNode {
   readonly category = 'Secure PDF' as const;
@@ -33,35 +33,13 @@ export class DecryptNode extends BaseWorkflowNode {
 
     return {
       pdf: await processBatch(pdfInputs, async (input) => {
-        const qpdf = await initializeQpdf();
-        const uid = `${Date.now()}_${Math.random().toString(36).slice(2, 9)}`;
-        const inputPath = `/tmp/input_decrypt_${uid}.pdf`;
-        const outputPath = `/tmp/output_decrypt_${uid}.pdf`;
-
-        let decryptedData: Uint8Array;
-        try {
-          qpdf.FS.writeFile(inputPath, input.bytes);
-          const args = password
-            ? [inputPath, '--password=' + password, '--decrypt', outputPath]
-            : [inputPath, '--decrypt', outputPath];
-          qpdf.callMain(args);
-
-          decryptedData = qpdf.FS.readFile(outputPath, { encoding: 'binary' });
-        } finally {
-          try {
-            qpdf.FS.unlink(inputPath);
-          } catch {
-            /* cleanup */
-          }
-          try {
-            qpdf.FS.unlink(outputPath);
-          } catch {
-            /* cleanup */
-          }
-        }
-
-        const resultBytes = new Uint8Array(decryptedData);
-        const document = await PDFDocument.load(resultBytes);
+        const { bytes: resultBytes } = await decryptPdfBytes(
+          input.bytes,
+          password
+        );
+        const document = await PDFDocument.load(resultBytes, {
+          throwOnInvalidObject: false,
+        });
 
         return {
           type: 'pdf',

src/js/workflow/nodes/pdf-input-node.ts

@@ -3,7 +3,8 @@ import { BaseWorkflowNode } from './base-node';
 import { pdfSocket } from '../sockets';
 import type { PDFData, SocketData, MultiPDFData } from '../types';
 import { PDFDocument } from 'pdf-lib';
-import { readFileAsArrayBuffer, initializeQpdf } from '../../utils/helpers.js';
+import { readFileAsArrayBuffer } from '../../utils/helpers.js';
+import { decryptPdfBytes } from '../../utils/pdf-decrypt.js';
 
 export class EncryptedPDFError extends Error {
   constructor(public readonly filename: string) {
@@ -63,44 +64,16 @@ export class PDFInputNode extends BaseWorkflowNode {
   async addDecryptedFile(file: File, password: string): Promise<void> {
     const arrayBuffer = await readFileAsArrayBuffer(file);
     const bytes = new Uint8Array(arrayBuffer as ArrayBuffer);
-    const qpdf = await initializeQpdf();
-    const uid = `${Date.now()}_${Math.random().toString(36).slice(2, 9)}`;
-    const inputPath = `/tmp/input_decrypt_${uid}.pdf`;
-    const outputPath = `/tmp/output_decrypt_${uid}.pdf`;
-
-    try {
-      qpdf.FS.writeFile(inputPath, bytes);
-      qpdf.callMain([
-        inputPath,
-        '--password=' + password,
-        '--decrypt',
-        outputPath,
-      ]);
-      const decryptedData = qpdf.FS.readFile(outputPath, {
-        encoding: 'binary',
-      });
-      const decryptedBytes = new Uint8Array(decryptedData);
-      const document = await PDFDocument.load(decryptedBytes, {
-        throwOnInvalidObject: false,
-      });
-      this.files.push({
-        type: 'pdf',
-        document,
-        bytes: decryptedBytes,
-        filename: file.name,
-      });
-    } finally {
-      try {
-        qpdf.FS.unlink(inputPath);
-      } catch {
-        /* cleanup */
-      }
-      try {
-        qpdf.FS.unlink(outputPath);
-      } catch {
-        /* cleanup */
-      }
-    }
+    const { bytes: decryptedBytes } = await decryptPdfBytes(bytes, password);
+    const document = await PDFDocument.load(decryptedBytes, {
+      throwOnInvalidObject: false,
+    });
+    this.files.push({
+      type: 'pdf',
+      document,
+      bytes: decryptedBytes,
+      filename: file.name,
+    });
   }
 
   async setFile(file: File): Promise<void> {

src/tests/pdf-decrypt.test.ts

@@ -0,0 +1,276 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+const {
+  mockGetCpdf,
+  mockIsCpdfAvailable,
+  mockLoadPyMuPDF,
+  mockIsPyMuPDFAvailable,
+  mockPdfDocumentLoad,
+  mockReadFileAsArrayBuffer,
+} = vi.hoisted(() => ({
+  mockGetCpdf: vi.fn(),
+  mockIsCpdfAvailable: vi.fn(),
+  mockLoadPyMuPDF: vi.fn(),
+  mockIsPyMuPDFAvailable: vi.fn(),
+  mockPdfDocumentLoad: vi.fn(),
+  mockReadFileAsArrayBuffer: vi.fn(),
+}));
+
+vi.mock('../js/utils/cpdf-helper', () => ({
+  getCpdf: mockGetCpdf,
+  isCpdfAvailable: mockIsCpdfAvailable,
+}));
+
+vi.mock('../js/utils/pymupdf-loader', () => ({
+  loadPyMuPDF: mockLoadPyMuPDF,
+  isPyMuPDFAvailable: mockIsPyMuPDFAvailable,
+}));
+
+vi.mock('pdf-lib', () => ({
+  PDFDocument: {
+    load: mockPdfDocumentLoad,
+  },
+}));
+
+vi.mock('../js/utils/helpers.js', () => ({
+  readFileAsArrayBuffer: mockReadFileAsArrayBuffer,
+}));
+
+import * as pdfDecryptModule from '../js/utils/pdf-decrypt';
+
+describe('pdf decrypt', () => {
+  let infoSpy: ReturnType<typeof vi.spyOn>;
+  let warnSpy: ReturnType<typeof vi.spyOn>;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    infoSpy = vi.spyOn(console, 'info').mockImplementation(() => {});
+    warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {});
+    mockIsCpdfAvailable.mockReturnValue(true);
+    mockIsPyMuPDFAvailable.mockReturnValue(true);
+    mockPdfDocumentLoad.mockResolvedValue({ loaded: true });
+    mockReadFileAsArrayBuffer.mockResolvedValue(
+      new Uint8Array([1, 2, 3]).buffer
+    );
+  });
+
+  it('uses CoherentPDF first when it succeeds', async () => {
+    const cpdf = {
+      setSlow: vi.fn(),
+      fromMemory: vi.fn().mockReturnValue({ pdf: true }),
+      isEncrypted: vi.fn().mockReturnValue(true),
+      decryptPdf: vi.fn(),
+      decryptPdfOwner: vi.fn(),
+      toMemory: vi.fn().mockReturnValue(new Uint8Array([4, 5, 6])),
+      deletePdf: vi.fn(),
+    };
+    mockGetCpdf.mockResolvedValue(cpdf);
+
+    const result = await pdfDecryptModule.decryptPdfBytes(
+      new Uint8Array([9]),
+      '1234'
+    );
+
+    expect(result).toEqual({
+      bytes: new Uint8Array([4, 5, 6]),
+      engine: 'cpdf',
+    });
+    expect(infoSpy).toHaveBeenCalledWith(
+      '[PDF Decrypt] Decryption succeeded with CoherentPDF'
+    );
+    expect(cpdf.decryptPdf).toHaveBeenCalledWith({ pdf: true }, '1234');
+    expect(mockLoadPyMuPDF).not.toHaveBeenCalled();
+  });
+
+  it('falls back to PyMuPDF when CoherentPDF fails', async () => {
+    const cpdf = {
+      setSlow: vi.fn(),
+      fromMemory: vi.fn().mockImplementation(() => {
+        throw new Error('cpdf failed');
+      }),
+      isEncrypted: vi.fn(),
+      decryptPdf: vi.fn(),
+      decryptPdfOwner: vi.fn(),
+      toMemory: vi.fn(),
+      deletePdf: vi.fn(),
+    };
+    const pymupdfDocument = {
+      needsPass: true,
+      isEncrypted: true,
+      authenticate: vi.fn().mockReturnValue(true),
+      save: vi.fn().mockReturnValue(new Uint8Array([7, 8, 9])),
+      close: vi.fn(),
+    };
+
+    mockGetCpdf.mockResolvedValue(cpdf);
+    mockLoadPyMuPDF.mockResolvedValue({
+      open: vi.fn().mockResolvedValue(pymupdfDocument),
+    });
+
+    const result = await pdfDecryptModule.decryptPdfBytes(
+      new Uint8Array([9]),
+      '1234'
+    );
+
+    expect(result).toEqual({
+      bytes: new Uint8Array([7, 8, 9]),
+      engine: 'pymupdf',
+    });
+    expect(warnSpy).toHaveBeenCalledWith(
+      '[PDF Decrypt] Decryption with CoherentPDF failed. Falling back to PyMuPDF. Reason: cpdf failed'
+    );
+    expect(infoSpy).toHaveBeenCalledWith(
+      '[PDF Decrypt] Decryption succeeded with PyMuPDF'
+    );
+    expect(pymupdfDocument.authenticate).toHaveBeenCalledWith('1234');
+    expect(pymupdfDocument.close).toHaveBeenCalledTimes(1);
+  });
+
+  it('normalizes raw CoherentPDF error strings before fallback logging', async () => {
+    const cpdf = {
+      setSlow: vi.fn(),
+      fromMemory: vi.fn().mockImplementation(() => {
+        throw '0,248,Exports.CPDFError,32,ERROR: decryptPdfOwner: Pdf.PDFError("Bad or missing /P entry")';
+      }),
+      isEncrypted: vi.fn(),
+      decryptPdf: vi.fn(),
+      decryptPdfOwner: vi.fn(),
+      toMemory: vi.fn(),
+      deletePdf: vi.fn(),
+    };
+    const pymupdfDocument = {
+      needsPass: false,
+      isEncrypted: false,
+      authenticate: vi.fn(),
+      save: vi.fn().mockReturnValue(new Uint8Array([7, 8, 9])),
+      close: vi.fn(),
+    };
+
+    mockGetCpdf.mockResolvedValue(cpdf);
+    mockLoadPyMuPDF.mockResolvedValue({
+      open: vi.fn().mockResolvedValue(pymupdfDocument),
+    });
+
+    const result = await pdfDecryptModule.decryptPdfBytes(
+      new Uint8Array([9]),
+      '1234'
+    );
+
+    expect(result.engine).toBe('pymupdf');
+    expect(warnSpy).toHaveBeenCalledWith(
+      '[PDF Decrypt] Decryption with CoherentPDF failed. Falling back to PyMuPDF. Reason: Bad or missing /P entry'
+    );
+  });
+
+  it('aggregates engine errors when decryption fails', async () => {
+    const cpdf = {
+      setSlow: vi.fn(),
+      fromMemory: vi.fn().mockImplementation(() => {
+        throw new Error('cpdf failed');
+      }),
+      isEncrypted: vi.fn(),
+      decryptPdf: vi.fn(),
+      decryptPdfOwner: vi.fn(),
+      toMemory: vi.fn(),
+      deletePdf: vi.fn(),
+    };
+    const pymupdfDocument = {
+      needsPass: true,
+      isEncrypted: true,
+      authenticate: vi.fn().mockReturnValue(false),
+      save: vi.fn(),
+      close: vi.fn(),
+    };
+
+    mockGetCpdf.mockResolvedValue(cpdf);
+    mockLoadPyMuPDF.mockResolvedValue({
+      open: vi.fn().mockResolvedValue(pymupdfDocument),
+    });
+
+    await expect(
+      pdfDecryptModule.decryptPdfBytes(new Uint8Array([9]), '1234')
+    ).rejects.toThrow(
+      'CoherentPDF: cpdf failed\nPyMuPDF: Invalid PDF password.'
+    );
+    expect(warnSpy).toHaveBeenCalledWith(
+      '[PDF Decrypt] PyMuPDF decryption failed: Invalid PDF password.'
+    );
+    expect(pymupdfDocument.close).toHaveBeenCalledTimes(1);
+  });
+
+  it('uses the shared decrypt helper in the workflow decrypt node', async () => {
+    const decryptSpy = vi
+      .spyOn(pdfDecryptModule, 'decryptPdfBytes')
+      .mockResolvedValue({
+        bytes: new Uint8Array([8, 8, 8]),
+        engine: 'cpdf',
+      });
+
+    const { DecryptNode } = await import('../js/workflow/nodes/decrypt-node');
+
+    const node = new DecryptNode();
+    const passwordControl = node.controls['password'] as { value?: string };
+    passwordControl.value = 'secret';
+
+    const result = await node.data({
+      pdf: [
+        {
+          type: 'pdf',
+          document: {} as never,
+          bytes: new Uint8Array([1, 2, 3]),
+          filename: 'locked.pdf',
+        },
+      ],
+    });
+
+    expect(decryptSpy).toHaveBeenCalledWith(
+      new Uint8Array([1, 2, 3]),
+      'secret'
+    );
+    expect(mockPdfDocumentLoad).toHaveBeenCalledWith(
+      new Uint8Array([8, 8, 8]),
+      {
+        throwOnInvalidObject: false,
+      }
+    );
+    expect(result.pdf).toEqual({
+      type: 'pdf',
+      document: { loaded: true },
+      bytes: new Uint8Array([8, 8, 8]),
+      filename: 'locked_decrypted.pdf',
+    });
+  });
+
+  it('uses the shared decrypt helper when adding a decrypted workflow input file', async () => {
+    const decryptSpy = vi
+      .spyOn(pdfDecryptModule, 'decryptPdfBytes')
+      .mockResolvedValue({
+        bytes: new Uint8Array([6, 6, 6]),
+        engine: 'cpdf',
+      });
+
+    const { PDFInputNode } =
+      await import('../js/workflow/nodes/pdf-input-node');
+
+    const node = new PDFInputNode();
+    const file = new File([new Uint8Array([1, 2, 3])], 'locked.pdf', {
+      type: 'application/pdf',
+    });
+
+    await node.addDecryptedFile(file, 'secret');
+
+    expect(mockReadFileAsArrayBuffer).toHaveBeenCalledWith(file);
+    expect(decryptSpy).toHaveBeenCalledWith(
+      new Uint8Array([1, 2, 3]),
+      'secret'
+    );
+    expect(mockPdfDocumentLoad).toHaveBeenCalledWith(
+      new Uint8Array([6, 6, 6]),
+      {
+        throwOnInvalidObject: false,
+      }
+    );
+    expect(node.getFileCount()).toBe(1);
+    expect(node.getFilenames()).toEqual(['locked.pdf']);
+  });
+});