Dart

RSAES-OAEP Encrypt String with AES-128 Content Encryption and SHA256

See more Encryption Examples

Encrypts a string using RSAES-OAEP with SHA256 and AES-128 content encryption to produce PKCS7 output (base64 encoded).

Note: This example requires Chilkat v9.5.0.67 or greater.

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.

  // First build a string to be encrypted
  final sb = CkStringBuilder();
  var i = 1;
  while (i < 25) {
    sb.appendInt(i);
    sb.append(' the quick brown fox jumped over the lazy dog.\r\n');
    i++;
  }

  print(sb.getAsString());

  // The string to be encrypted looks like this:

  // 1 the quick brown fox jumped over the lazy dog.
  // 2 the quick brown fox jumped over the lazy dog.
  // 3 the quick brown fox jumped over the lazy dog.
  // 4 the quick brown fox jumped over the lazy dog.
  // 5 the quick brown fox jumped over the lazy dog.
  // 6 the quick brown fox jumped over the lazy dog.
  // ...

  // Load a digital certificate. 
  // We don't need the private key for encryption.
  // Only the public key is needed (which is included in a certificate).
  final cert = CkCert();
  try {
    cert.loadFromFile('qa_data/rsaes-oaep/cert.pem');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final crypt = CkCrypt2();

  // Tell the crypt object to use the certificate.
  crypt.setEncryptCert(cert);

  // Indicate that we want PKI encryption (i.e. public-key infrastructure)
  // to produce a CMS message (Cryptographic Message Syntax/PKCS7),
  // that is be created with RSAES-OAEP padding, SHA256, and AES-128 for the
  // bulk encryption.
  crypt.cryptAlgorithm = 'pki';
  crypt.pkcs7CryptAlg = 'aes';
  crypt.keyLength = 128;
  crypt.oaepHash = 'sha256';
  crypt.oaepPadding = true;

  // Also, don't forget to be specific about the character encoding (byte representation) of the
  // string to be encrypted.
  crypt.charset = 'utf-8';

  // Now indicate that the PKCS7 output is to be returned in the base64 encoding.
  crypt.encodingMode = 'base64';

  final String base64Pkcs7;
  try {
    base64Pkcs7 = crypt.encryptStringENC(sb.getAsString());
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Show the output
  print(base64Pkcs7);

  // This base64 can be copy-and-pasted into the form at http://lapo.it/asn1js/
  // to verify that all the chosen algorithms were indeed used.

  print('OK.');
}