Dart

Encrypt/Decrypt using PFX to produce -----BEGIN PKCS7----- ... -----END PKCS7-----

See more Encryption Examples

First we encrypt using a certificate + public key to produce output such as:

-----BEGIN PKCS7-----
MIIHPwYJKoZIhvcNAQcEoIIHMDCCBywC ...
...
...
-----END PKCS7-----

Then we decrypt using the cert + private key. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  var success = false;

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

  final crypt = CkCrypt2();

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

  // A certificate is needed as the encryption key.
  // Althought the PFX contains the associated private key, we don't need it for encryption.
  // (A certificate usually contains the public key by default.)
  final cert = CkCert();
  success = true;
  try {
    cert.loadPfxFile('qa_data/pfx/cert_test123.pfx', 'test123');
  } on ChilkatException {
    success = false;
  }
  if (!success) {
    print(cert.lastErrorText);
    return;
  }

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

  final toBeEncrypted = 'This string is to be encrypted.';

  // Get the result in multi-line BASE64 MIME format.
  crypt.encodingMode = 'base64_mime';

  final encryptedStr = crypt.encryptStringENC(toBeEncrypted);
  if (!success) {
    print(crypt.lastErrorText);
    return;
  }

  // Make a "-----BEGIN PKCS7-----" ... "-----END PKCS7-----" sandwich...
  final sb = CkStringBuilder();
  sb.appendLine('-----BEGIN PKCS7-----', true);
  sb.append(encryptedStr);
  sb.appendLine('-----END PKCS7-----', true);

  final outStr = sb.getAsString();

  print(outStr);

  // Sample output:

  // -----BEGIN PKCS7-----
  // MIICXAYJKoZIhvcNAQcDoIICTTCCAkkCAQAxggH0MIIB8AIBADCBrDCBlzELMAkGA1UEBhMCR0Ix
  // GzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4GA1UEBxMHU2FsZm9yZDEaMBgGA1UEChMR
  // Q09NT0RPIENBIExpbWl0ZWQxPTA7BgNVBAMTNENPTU9ETyBSU0EgQ2xpZW50IEF1dGhlbnRpY2F0
  // aW9uIGFuZCBTZWN1cmUgRW1haWwgQ0ECEB6M1ZwZdZU7LrAIdurulmUwOAYJKoZIhvcNAQEHMCug
  // DzANBglghkgBZQMEAgEFAKEYMBYGCSqGSIb3DQEBCDAJBgUrDgMCGgUABIIBAK/BZG/iXJ8az7zL
  // 8EQ77mc+oDPQ4w1hyytK2ip4djkPVvTfYhcoDQ+G/DBU+urJfrVBi5H9gmpXwYyfKlyUxBVRVEJl
  // V/V5QQi4JmNTFbmgWh5tp9zDS98l6A2Va4Zs0Wy/owGLfvwitlxd1dsfVAV2hmBYS24BMpNcty5/
  // 0atcKYmSou13G78ztTKdMy1tECgZy8kerMsPdDQbSxEZkT3KpQ8C5uEQqYF3bIVaeZzha/Ywieh/
  // tvO0T4aAmeJufwkNdVECmU7kuhnNaVPXknFl7jeibTl6zA/VcJKBKcIYT9FRC7KjdooI8q+jtQ/V
  // k6RP4POaowkFg1QWRPEWeqIwTAYJKoZIhvcNAQcBMB0GCWCGSAFlAwQBAgQQEEFQduqeJqXQXzy4
  // JpkoDoAgdldJDB9zEkpMpgr5/fR2iLvh5kC6BPfhOYjsawBY4Ok=
  // -----END PKCS7-----

  // ----------------------------------------------------------------------------------------
  // Let's Decrypt the above string.

  // Start with what was produced above..
  sb.clear();
  final bCrlf = true;
  sb.appendLine('-----BEGIN PKCS7-----', bCrlf);
  sb.appendLine('MIICXAYJKoZIhvcNAQcDoIICTTCCAkkCAQAxggH0MIIB8AIBADCBrDCBlzELMAkGA1UEBhMCR0Ix', bCrlf);
  sb.appendLine('GzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4GA1UEBxMHU2FsZm9yZDEaMBgGA1UEChMR', bCrlf);
  sb.appendLine('Q09NT0RPIENBIExpbWl0ZWQxPTA7BgNVBAMTNENPTU9ETyBSU0EgQ2xpZW50IEF1dGhlbnRpY2F0', bCrlf);
  sb.appendLine('aW9uIGFuZCBTZWN1cmUgRW1haWwgQ0ECEB6M1ZwZdZU7LrAIdurulmUwOAYJKoZIhvcNAQEHMCug', bCrlf);
  sb.appendLine('DzANBglghkgBZQMEAgEFAKEYMBYGCSqGSIb3DQEBCDAJBgUrDgMCGgUABIIBAK/BZG/iXJ8az7zL', bCrlf);
  sb.appendLine('8EQ77mc+oDPQ4w1hyytK2ip4djkPVvTfYhcoDQ+G/DBU+urJfrVBi5H9gmpXwYyfKlyUxBVRVEJl', bCrlf);
  sb.appendLine('V/V5QQi4JmNTFbmgWh5tp9zDS98l6A2Va4Zs0Wy/owGLfvwitlxd1dsfVAV2hmBYS24BMpNcty5/', bCrlf);
  sb.appendLine('0atcKYmSou13G78ztTKdMy1tECgZy8kerMsPdDQbSxEZkT3KpQ8C5uEQqYF3bIVaeZzha/Ywieh/', bCrlf);
  sb.appendLine('tvO0T4aAmeJufwkNdVECmU7kuhnNaVPXknFl7jeibTl6zA/VcJKBKcIYT9FRC7KjdooI8q+jtQ/V', bCrlf);
  sb.appendLine('k6RP4POaowkFg1QWRPEWeqIwTAYJKoZIhvcNAQcBMB0GCWCGSAFlAwQBAgQQEEFQduqeJqXQXzy4', bCrlf);
  sb.appendLine('JpkoDoAgdldJDB9zEkpMpgr5/fR2iLvh5kC6BPfhOYjsawBY4Ok=', bCrlf);
  sb.appendLine('-----END PKCS7-----', bCrlf);

  final decrypt = CkCrypt2();
  decrypt.cryptAlgorithm = 'pki';

  // Use the same cert + private key from the PFX above.
  // For decryption, we need the private key.  Given that the certificate was loaded from a PFX,
  // we should already have it.
  success = true;
  try {
    decrypt.setDecryptCert(cert);
  } on ChilkatException {
    success = false;
  }

  decrypt.encodingMode = 'base64';
  final decryptedText = decrypt.decryptStringENC(sb.getBetween('-----BEGIN PKCS7-----', '-----END PKCS7-----'));

  print(decryptedText);
}