(PHP Extension) 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 PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

$cert = new CkCert();

// 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 != true) {
    print $cert->lastErrorText() . "\n";
    exit;
}

// Get the public key:

// pubkey is a CkPublicKey
$pubkey = $cert->ExportPublicKey();
if ($cert->get_LastMethodSuccess() == false) {
    print $cert->lastErrorText() . "\n";
    exit;
}

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

    exit;
}

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

    exit;
}

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

    exit;
}

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

    exit;
}

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

?>