Dart

Encrypt File using X.509 Certificate using AES in CBC Mode

See more Encryption Examples

Demonstrates how to encrypt a file using an X.509 Certificate's public key, where the underlying bulk encryption algorithm is 128-bit AES in CBC mode. (The underlying bulk encryption algorithm can be specified to be other algorithms/strengths.) 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.

  final crypt = CkCrypt2();

  // Use public-key cryptography for encryption.
  crypt.cryptAlgorithm = 'pki';

  // Get an X.509 certificate to use for encrypting.
  // Note: Chilkat provides many different ways of loading a certificate, from many different formats,
  // or if on Windows, from the installed certificates on the system.
  // This example simply loads a certificate from a file.
  // Also, for encryption, only the public key is needed.  Digital certificates embed the public key
  // within the X.509 format itself.  Therefore, if you have a certificate, you also have the public key.
  final cert = CkCert();
  try {
    cert.loadFromFile('qa_data/certs/testCert.cer');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  try {
    crypt.setEncryptCert(cert);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Indicate the underlying bulk encryption algorithm to be used:
  crypt.pkcs7CryptAlg = 'aes';
  crypt.keyLength = 128;

  // Note: When doing public-key encryption the underlying bulk symmetric cipher mode will always be CBC. (at least with Chilkat...)

  // There's one last option that could be set.  If is the RSA encryption encryption/padding scheme. 
  // By default, RSAES_PKCS1-V1_5 is used.  If desired, the OaepPadding property could be set to true to
  // use RSAES_OAEP.  (We'll leave it set at the default value of false)
  crypt.oaepPadding = false;

  // Everything is specified.  Now just encrypt...
  // The output is PKCS7 in binary DER format.
  try {
    crypt.ckEncryptFile('qa_data/hamlet.xml', 'qa_output/hamlet.p7');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Finished.');
}