Dart Requires Chilkat v11.7.0+

Remove the Password and Encryption from a PDF

See more PDF Protection Examples

Demonstrates the removeEncryption operation, which saves the PDF with no encryption at all: no password, no restrictions. It needs owner rights, so the PDF is loaded with its owner password. As with every Protection operation, the change is applied when the file is written. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // 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 encrypted_user_password.pdf

  final pdf = CkPdf();

  // Removing the encryption needs owner rights: load with the owner password.
  pdf.ownerPassword = 'owner-secret';
  try {
    pdf.loadFile('qa_data/pdf/encrypted_user_password.pdf');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final json = CkJsonObject();
  final jsonOut = CkJsonObject();
  try {
    pdf.protection('getInfo', json, jsonOut);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('encrypted, as loaded: ${jsonOut.boolOf('loaded.encrypted')}');
  print('algorithm: ${jsonOut.stringOf('loaded.algorithm')}');

  try {
    pdf.protection('removeEncryption', json, jsonOut);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('will be saved encrypted: ${jsonOut.boolOf('pending.encrypted')}');

  try {
    pdf.writeFile('qa_output/minutes_unprotected.pdf');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // The result is an ordinary PDF that opens without a password.
  final reader = CkPdf();
  final info = CkJsonObject();
  try {
    reader.preLoadCheck('qa_output/minutes_unprotected.pdf', info);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('encrypted: ${info.boolOf('encrypted')}');
  try {
    reader.loadFile('qa_output/minutes_unprotected.pdf');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('pages: ${reader.numPages}');

  // Sample output:

  // encrypted, as loaded: True
  // algorithm: rc4-128
  // will be saved encrypted: False
  // encrypted: False
  // pages: 1
}