(PHP ActiveX) 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.)

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows Note: The php_com_dotnet.dll may need to be enabled inside of php.ini.

<?php

// 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.
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.MailMan')
$mailman = new COM("Chilkat.MailMan");

// 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.
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Cert')
$cert = new COM("Chilkat.Cert");
$success = $cert->LoadFromFile('cknotes.cer');
if ($success != 1) {
    print $cert->LastErrorText . "\n";
    exit;
}

// Create a new email object
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Email')
$email = new COM("Chilkat.Email");

$email->Subject = 'This email is encrypted';
$email->Body = 'This is a digitally encrypted mail';
$email->From = 'Chilkat Support <support@chilkatsoft.com>';
$success = $email->AddTo('Chilkat Blog','admin@cknotes.com');

// Indicate that the email is to be sent encrypted.
$email->SendEncrypted = 1;

// Specify the certificate to be used for encryption.
$success = $email->SetEncryptCert($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;

$success = $mailman->SendEmail($email);
if ($success != 1) {
    print $mailman->LastErrorText . "\n";
}
else {
    print 'Mail Sent!' . "\n";
}


?>