Dart Requires Chilkat v10.1.2+

Send Signed Email using PFX File (long version)

Demonstrates how to send a signed email using a digital certificate w/ private key stored in a PFX file. 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';

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

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

  // Indicate that the email should be sent signed.
  email.sendSigned = true;

  // Load a PFX file into a certificate store object.
  // Then locate the certificate matching the  sender's email address,
  // and use it for signing.
  // (a PFX file may contain more than one certificate.)
  final certStore = CkCertStore();
  // The 1st argument is the path of the PFX file, the 2nd arg is the 
  // PFX file's password:
  try {
    certStore.loadPfxFile('/pfx_files/chilkatsoft_secret.pfx', 'secret');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Find the certificate for the email address:
  final jsonE = CkJsonObject();
  jsonE.updateString('email', 'admin@chilkatsoft.com');

  final cert = CkCert();
  try {
    certStore.findCert(jsonE, cert);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Alternatively, if a PFX file is known to contain a single certificate,
  // you may load it directly into a Chilkat certificate object.
  // This snippet of source code shows how:
  final cert2 = CkCert();
  // The 1st argument is the filename, the 2nd arg is the 
  // PFX file's password:
  try {
    cert2.loadPfxFile('/pfx_files/chilkatsoft_secret.pfx', 'secret');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // This example will use the cert from the certStore...
  email.setSigningCert(cert);

  // Signed email can be sent in two different ways.  
  // In a multipart/signed email, the signature is attached as a separate MIME part.
  // In an opaque email (signedData) the content of the email is encapsulated within the signature
  // and the email is sent as "application/pkcs7-mime". 
  // Either should be fine, but some receiving systems might require one or the other..
  mailman.opaqueSigning = false;

  // Send a signed email.
  try {
    mailman.sendEmail(email);
    // The LastErrorText property provides information
    // even when successful.
    print(mailman.lastErrorText);
    print('Mail Sent!');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
  }
}