Select Encryption Algorithm with SMTP Encrypted Email

Demonstrates how to select the encryption algorithm and strength (key size) when sending encrypted email.

Download Chilkat Perl Module

use chilkat;

#  The mailman object is used for sending and receiving email.
$mailman = new chilkat::CkMailMan();

#  Any string argument automatically begins the 30-day trial.
$success = $mailman->UnlockComponent("30-day trial");
if ($success != 1) {
    print "Component unlock failed" . "\n";
    exit;
}

#  Set the SMTP server.
$mailman->put_SmtpHost("smtp.comcast.net");

#  Create a new email object
$email = new chilkat::CkEmail();

$email->put_Subject("This email is encrypted");
$email->put_Body("This is a digitally encrypted mail");
$email->put_From('Chilkat Support <support@chilkatsoft.com>');
$email->AddTo("Chilkat Admin",'admin@chilkatsoft.com');

#  In this example, we've already installed the certificate for "admin@chilkatsoft.com"
#  in the current user's personal certificate store.
#  If the email.SendEncrypted property is set, Chilkat will
#  automatically search for and use the first non-expired certificate
#  matching the recipient's email address.  Chilkat searches
#  the Current User's Personal certificate store, as well
#  as the Local Machine's Personal certificate store.
#  Run certmgr.msc to view the certs in the Current User's
#  certificate store.
$email->put_SendEncrypted(1);

#  Use the CSP object to select an encryption algorithm:
$csp = new chilkat::CkCSP();
#  Make sure we're using the enhanced provider, which provides
#  access to stronger algorithms.
$csp->SetProviderMicrosoftEnhanced();

#  Select 168-bit 3DES (i.e. 192-bit DES if you include the parity bits)
$csp->SetEncryptAlgorithm("3DES");

#  Tell the email to use this CSP:
$email->SetCSP($csp);

$success = $mailman->SendEmail($email);
if ($success != 1) {
    print $mailman->lastErrorText() . "\n";
}
else {
    #  Examine the LastErrorText anyway, so we can see
    #  that 3DES was used...
    #  You should see these lines in the log:
    #  alg_name: 3DES
    #  alg_bits: 168
    print $mailman->lastErrorText() . "\n";
}