(PHP ActiveX) Export Digital Certificate's Public Key

The ExportPublicKey method can be called to get a certificate's public key. It can then be saved to any of a number of formats: (1) OpenSSL DER, (2) OpenSSL PEM, (3) RSA DER, (4) XML.

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

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

// LoadFromFile will load virtually any certificate format file.
// It will auto-recognize the format and load appropiately.
$success = $cert->LoadFromFile('/Users/chilkat/testData/cer/chilkat.cer');
if ($success != 1) {
    print $cert->LastErrorText . "\n";
    exit;
}

// Get the public key:

// pubkey is a Chilkat.PublicKey
$pubkey = $cert->ExportPublicKey();
if ($cert->LastMethodSuccess == 0) {
    print $cert->LastErrorText . "\n";
    exit;
}

// Save to various formats:
$success = $pubkey->SaveDerFile(0,'/Users/chilkat/testData/pubkeys/chilkat_pkcs8.der');
if ($success != 1) {
    print $pubkey->LastErrorText . "\n";

    exit;
}

$success = $pubkey->SavePemFile(0,'/Users/chilkat/testData/pubkeys/chilkat.pem');
if ($success != 1) {
    print $pubkey->LastErrorText . "\n";

    exit;
}

$success = $pubkey->SaveDerFile(1,'/Users/chilkat/testData/pubkeys/chilkat_pkcs1.der');
if ($success != 1) {
    print $pubkey->LastErrorText . "\n";

    exit;
}

$success = $pubkey->SaveXmlFile('/Users/chilkat/testData/pubkeys/chilkat.xml');
if ($success != 1) {
    print $pubkey->LastErrorText . "\n";

    exit;
}

print 'Public key exported to all file formats.' . "\n";

?>