Dart

RSAES-OAEP Encrypt/Decrypt Binary Data with AES-128 and SHA56

See more Encryption Examples

Demonstrates the use of the new EncryptBd and DecryptBd methods introduced in Chilkat v9.5.0.67 to create a PKCS7/CMS (Cryptographic Message Syntax) message using RSAES-OAEP with AES-128 and SHA256.

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.

  // Load a small JPG file to be encrypted/decrypted.
  final jpgBytes = CkBinData();
  try {
    jpgBytes.loadFile('qa_data/jpg/starfish20.jpg');
  } on ChilkatException {
    print('Failed to load JPG file.');
    return;
  }

  // Show the unencrypted JPG bytes in Base64 format.
  // (The "base64_mime" encoding was added in Chilkat v9.5.0.67.
  // The "base64" encoding emits a single line of base64, whereas
  // "base64_mime" will emit multi-line base64 as it would appear
  // in MIME.)
  print(jpgBytes.getEncoded('base64_mime'));

  // Sample base64_mime JPG data:

  // /9j/4AAQSkZJRgABAQEASABIAAD//gAmRmlsZSB3cml0dGVuIGJ5IEFkb2JlIFBob3Rvc2hvcD8g
  // NC4w/9sAQwAQCwwODAoQDg0OEhEQExgoGhgWFhgxIyUdKDozPTw5Mzg3QEhcTkBEV0U3OFBtUVdf
  // YmdoZz5NcXlwZHhcZWdj/9sAQwEREhIYFRgvGhovY0I4QmNjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj
  // Y2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj/8IAEQgAFAAUAwERAAIRAQMRAf/EABcAAAMBAAAA
  // AAAAAAAAAAAAAAIDBAX/xAAYAQADAQEAAAAAAAAAAAAAAAABAgMEAP/aAAwDAQACEAMQAAAB2kZY
  // NNEijWKddfTmLgALWH//xAAbEAACAgMBAAAAAAAAAAAAAAABAgMRAAQSE//aAAgBAQABBQL0XqN+
  // pM2aqJGMiqFFCyg7z//EABwRAAICAgMAAAAAAAAAAAAAAAERAAIQIQMSUf/aAAgBAwEBPwHqU5aq
  // Axx+y1tMQl4elj//xAAcEQEAAQUBAQAAAAAAAAAAAAABEQACEBIhA1H/2gAIAQIBAT8B3Bhqy7Zc
  // enyiwmGgDhiOzj//xAAdEAABAwUBAAAAAAAAAAAAAAABAAIREBIhIkFR/9oACAEBAAY/ArZyn+Cg
  // xtxWuJaoCnqDuin/xAAcEAABBAMBAAAAAAAAAAAAAAABABEhYRAxQVH/2gAIAQEAAT8hkEwPUUR9
  // DYfE4nxtRpIkBTsayuALIiuY/9oADAMBAAIAAwAAABDWPTsf/8QAGhEAAwADAQAAAAAAAAAAAAAA
  // AAEREDFBIf/aAAgBAwEBPxC0DVPcWm+Ce4OesrkE6bjH/8QAGBEBAQEBAQAAAAAAAAAAAAAAAREA
  // QRD/2gAIAQIBAT8QahMiOc8YgSrnTY3ELclHXn//xAAcEAEBAAIDAQEAAAAAAAAAAAABEQAhMUFx
  // EFH/2gAIAQEAAT8Qn3igmSZSj+c4N4zapMy9IjFV98wncN2iuLFsCEbDGxQkI6RO/n//2Q==

  final crypt = CkCrypt2();

  // Specify the encryption to be used.
  // "pki" indicates "Public Key Infrastructure" and will create a PKCS7/CMS message.
  crypt.cryptAlgorithm = 'pki';
  crypt.pkcs7CryptAlg = 'aes';
  crypt.keyLength = 128;
  crypt.oaepHash = 'sha256';
  crypt.oaepPadding = true;

  // A certificate is needed as the encryption key..
  final cert = CkCert();
  try {
    cert.loadFromFile('qa_data/rsaes-oaep/cert.pem');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

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

  // Do the in-place RSAES-OAEP encryption.
  // The contents of jpgBytes are replaced with the CMS message.
  try {
    crypt.encryptBd(jpgBytes);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Examine the JPG bytes again.  The bytes should be different because they are encrypted:
  print(jpgBytes.getEncoded('base64_mime'));

  // Sample CMS message:
  // This CMS message can be copy-and-pasted into the online web form
  // at https://lapo.it/asn1js/   to verify the algorithms used.

  // MIIFDAYJKoZIhvcNAQcDoIIE/TCCBPkCAQAxggGgMIIBnAIBADB1MGgxCzAJBgNVBAYTAlVTMQsw
  // CQYDVQQIDAJJTDEQMA4GA1UEBwwHV2hlYXRvbjEhMB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQ
  // dHkgTHRkMRcwFQYDVQQDDA5DaGlsa2F0V2lkZ2V0cwIJAMRwugDmvniwMBwGCSqGSIb3DQEBBzAP
  // oA0wCwYJYIZIAWUDBAIBBIIBAHyWLgkJfIvoA3cYEAR/uHfA7uoi4eQXHl2woQAd6W5BbUNVBcYD
  // zuCTTOTWo1e7Uh0j0AhMZvVQf3+cngTiimzKwIZ2LNuNAgYOhrO/7coHyB22ImVetncUpCsAv/u7
  // 2tYp1dO36T56K+2hMELwcQXTj6v5ODO6a3emdCjITCjHhlYePvq2l0HyU2ALG5RFB6ldk9imhKzn
  // 6gfcijfH65S+KfMRlFBCXFu5nCBKmi8Ywo8Ue0rFssUDKLCjCeQNY52symiDbN/d06K/luOUwVhY
  // 1KQffdIKmTrZUugw+FaoQRq0xGj39T/sYu8qCinNZu/vPdUmxcXszSaSVJ/LGwcwggNOBgkqhkiG
  // 9w0BBwEwHQYJYIZIAWUDBAECBBDLnqRASqqnNUV2IiDkTRl/gIIDIPRaxdKEjhR5RD7pc7yI5j7N
  // TioZNvuMETdHWgHy7eOGz+1hP7fObk/RI0mtQx7IPEjkxaduNbXNzTpXAVRVj4Fw1zzXlqh9UPwt
  // p3TN3NsVRPQ5GmQ+cnPTSZD8i3i8ru8WFHyj1M6vyA0phrEGltKgqsZbb+OkuO5qG3laJv4XGkmn
  // 039pPGSTydQzW+HAp/hsJZLEMwdngXToi854ytjEk+ahCkeOz+d2MAfXZAR+nBCkmAmCQ9SDVTqH
  // FVJOAV2WrKBqNv4+iMn63f7QeoVIjk0QTE8D2iRsUiFYjy4ICaUpplLJEewneH5l0W40KA2+mOep
  // lIrvWnaX2H8ltOEBGD6Jng7i6p/Q4Lr+Y+HBYIHsBPLox3A4NOh/b0MZcyBr/AV2CsIwkIUGLlYl
  // /3rnpl7dRTuHP+fe1lDQVLAxD+U0c73sW7vOALhEe2t2Ae3ayukWPRyfXK9FNHAMhcOI4stHNSwx
  // o2fHa+ctTpPh0V5CHY/ELAKKkrH3nW954pk52tc8Xt6CnzVO5ry/ndcmTlQA0PkG6CK98TE9hCTA
  // hBdSL4/gVFgi9c35I6VXieY9kJe5ICljw5Ftm5yqTwlJIxGU3Z/WeIYBF4uyMegG75AQ9Md9tX0h
  // w8OOu2b6sIvxOZ+durIrYQDlXUXU/IR9exzAlYFENNBPhBgtDsWKSx5gcp+32kC5wtSYSiy3JxNt
  // 0W1yEJz8JGZXhuUvRXjwf+AjS4+/o82WTNXVLVKZ0TP50NVvtf9QqWuXvK/kDDPx6w+abK/aqdAs
  // QSL7wCxOosR2YUPWbXtwGhyHbIfAwWXijO2RnrqKeXL25Ywg16LQUTHq9Mlbgfw/tx3l5pjrmqFC
  // e9t9aaU6kDZqyyfRDOeWwkuDIsT90ulazbed2apgUXYj6AVVvMiC1pRld9wSuHH0vW0x5VsNbmXy
  // EY0NJlJY6II/1szy3bpiP6MsqFveCyCX8rM7UgGgpMNbvWPnsX0F/0eJywIrXrnQYXpvfgghIrlr
  // qu/ftXWypfcfvATxme+cN2EBsCDhq4VcMgB6JY3ykv6P8PK/QpMTbu4Y

  // To decrypt, we'll need the cert with private key.  
  // (The certificate alone contains only the public key.)
  // Provide the required cert + private key from a PFX (.pfx/.p12) file.
  try {
    crypt.addPfxSourceFile('qa_data/rsaes-oaep/cert_plus_privatekey.pfx', 'PFX_PASSWORD');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Decrypt to restore back to the original:
  try {
    crypt.decryptBd(jpgBytes);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print(jpgBytes.getEncoded('base64_mime'));
}