React Native Requires Chilkat v11.7.0+

Password-Protect a PDF with AES-256 Encryption

See more PDF Protection Examples

Demonstrates the simplest way to encrypt a PDF so that it needs a password to open. The passwords come from the UserPassword and OwnerPassword properties, and Protection with the encrypt operation and an empty JSON uses the defaults: AES-256, everything encrypted, every permission granted. Protection only records the security the PDF will be saved with. Nothing is encrypted until WriteFile is called. React Native

import { JsonObject, Pdf } from '@chilkat/react-native'

function chilkatExample() {
  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  // The PDF used in this example is available at two_page_memo.pdf

  const pdf = new Pdf();
  try {
    pdf.loadFile('qa_data/pdf/two_page_memo.pdf');
  } catch {
    console.log(pdf.lastErrorText);
    return;
  }

  // The passwords are taken from these two properties at the time Protection is called.
  // The user password opens the PDF.  The owner password opens it too, and is the one needed
  // later to change or remove the protection.
  pdf.userPassword = 'user-secret';
  pdf.ownerPassword = 'owner-secret';

  // An empty JSON asks for the defaults: AES-256, everything encrypted, every permission granted.
  const json = new JsonObject();
  const jsonOut = new JsonObject();
  try {
    pdf.protection('encrypt', json, jsonOut);
  } catch {
    console.log(pdf.lastErrorText);
    return;
  }

  // Nothing has been encrypted yet.  "pending" describes the security the PDF will be saved with.
  console.log(`algorithm: ${jsonOut.stringOf('pending.algorithm')}`);
  console.log(`PDF version: ${jsonOut.stringOf('pending.pdfVersion')}`);
  console.log(`password needed to open: ${jsonOut.boolOf('pending.userPasswordRequired')}`);

  // Writing the file applies it.
  try {
    pdf.writeFile('qa_output/memo_encrypted.pdf');
  } catch {
    console.log(pdf.lastErrorText);
    return;
  }

  // PreLoadCheck reports a file's encryption without loading it, and needs no password.
  const checker = new Pdf();
  const info = new JsonObject();
  try {
    checker.preLoadCheck('qa_output/memo_encrypted.pdf', info);
  } catch {
    console.log(checker.lastErrorText);
    return;
  }

  console.log(`encrypted: ${info.boolOf('encrypted')}`);
  console.log(`openPasswordRequired: ${info.boolOf('openPasswordRequired')}`);

  // With the password, the PDF opens normally.
  const reader = new Pdf();
  reader.userPassword = 'user-secret';
  try {
    reader.loadFile('qa_output/memo_encrypted.pdf');
  } catch {
    console.log(reader.lastErrorText);
    return;
  }

  console.log(`pages: ${reader.numPages}`);

  // Sample output:

  // algorithm: aes-256
  // PDF version: 1.7
  // password needed to open: True
  // encrypted: True
  // openPasswordRequired: True
  // pages: 2
}