(PHP ActiveX) Add DomainKey-Signature Header to MIME / Email

Demonstrates how to add a DomainKey-Signature header field to a MIME message.

Note: The DKIM / DomainKey functionality is included with the Chilkat MIME license.

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.

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

// To create a DomainKey signature for email (i.e. MIME),
// you'll need to provide the following:
// (1) An RSA private key in any common file format.
// (2) The domain name (typically the same domain
// as the sender of an email).
// (3) A selector for the domain name -- an arbitrary string
// to identify the matching public key in DNS.

// To allow an email recipient to verify the DomainKey signature via an
// external email client supporting DomainKey or using other software,
// you will need to create a DNS record with the selector
// and matching public key.  This example does not provide
// information about DomainKey DNS record creation.  
// (Chilkat does not provide an API for creating DNS records.  
// Creating the DomainKey DNS record is something you would do
// manually.)

// Set the domain and selector:
// You'll need to provide your own values here..
$dkim->DomainKeyDomain = 'chilkatsoft.com';
$dkim->DomainKeySelector = 'salmon';

// Load a private key from any common RSA private key
// format, such as DER, PKCS8, PEM, XML, etc.
// The LoadDomainKeyPkFile method automatically detects
// the file format and reads it appropriately.
// If a password is not required, you'll still need to provide
// a password string argument, but it is ignored.

$password = 'optionalPassword';
$success = $dkim->LoadDomainKeyPkFile('myPrivateKey.pem',$password);
if ($success != 1) {
    print $dkim->LastErrorText . "\n";
    exit;
}

// Load a MIME file into a byte array.
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.FileAccess')
$fac = new COM("Chilkat.FileAccess");

$mimeData = $fac->ReadEntireFile('testMessage.eml');
if ($fac->LastMethodSuccess != 1) {
    print $fac->LastErrorText . "\n";
    exit;
}

// Sign it.  This adds the DomainKey-Signature header and
// returns the new MIME with DomainKey-Signature added.

$domainKeySignedMime = $dkim->AddDomainKeySignature($mimeData);
if ($dkim->LastMethodSuccess != 1) {
    print $dkim->LastErrorText . "\n";
    exit;
}

$success = $fac->WriteEntireFile('domainKeySigned.eml',$domainKeySignedMime);
if ($success != 1) {
    print $fac->LastErrorText . "\n";
    exit;
}

print 'Success.' . "\n";

?>