Dart

Send Encrypted Email with a Selected Algorithm (AES, 3DES, etc.)

Sends an encrypted email using the recipient's digital certificate from a .cer file, and chooses 3DES for the encryption algorithm. (It is also possible to send AES encrypted email w/ 128-bit, 192-bit, or 256-bit encryption simply by setting the Pkcs7CryptAlg and Pkcs7KeyLength properties.) 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 mailman object is used for sending and receiving email.
  final mailman = CkMailMan();

  // Set the SMTP server.
  mailman.smtpHost = 'smtp.mymailserver.com';

  // Load the .cer file into a certificate object.
  // When sending S/MIME encrypted email, it is the recipient's
  // certificate that is used for encryption.  Only the public key
  // is needed to encrypt.  The recipient is the only
  // one possessing the private key, and therefore is the only
  // one able to decrypt.
  final cert = CkCert();
  try {
    cert.loadFromFile('cknotes.cer');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Create a new email object
  final email = CkEmail();

  email.subject = 'This email is encrypted';
  email.body = 'This is a digitally encrypted mail';
  email.from = 'Chilkat Support <support@chilkatsoft.com>';
  email.addTo('Chilkat Blog', 'admin@cknotes.com');

  // Indicate that the email is to be sent encrypted.
  email.sendEncrypted = true;

  // Specify the certificate to be used for encryption.
  email.setEncryptCert(cert);

  // If desired, specify the encryption algorithm to be used.
  // The Pkcs7CryptAlg property can be set to "aes", "des", "3des", or "rc2"
  email.pkcs7CryptAlg = '3des';

  // If desired, set the key length (in bits) for the encryption algorithm:
  // The possible values allowed depend on the Pkcs7CryptAlg property. 
  // For "aes", the key length may be 128, 192, or 256. 
  // For "3des" the key length must be 192. 
  // For "des" the key length must be 40. 
  // For "rc2" the key length can be 40, 56, 64, or 128.
  email.pkcs7KeyLength = 192;

  try {
    mailman.sendEmail(email);
    print('Mail Sent!');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
  }
}