(PHP ActiveX) Export a Certificate's Private Key to Various Formats

Loads a digital certificate and private key from a PFX file (also known as PKCS#12) and exports the private key to various formats: (1) PKCS8 Encrypted, (2) PKCS8 Encrypted PEM, (3) PKCS8 unencrypted, (4) PKCS8 PEM unencrypted, (5) RSA DER unencrypted, (6) RSA PEM unencrypted, (7) 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");

// Load from the PFX file
$pfxFilename = '/Users/chilkat/testData/pfx/chilkat_ssl_pwd_is_test.pfx';
$pfxPassword = 'test';

// A PFX typically contains certificates in the chain of authentication.
// The Chilkat cert object will choose the certificate w/
// private key farthest from the root authority cert.
// To access all the certificates in a PFX, use the 
// Chilkat certificate store object instead.
$success = $cert->LoadPfxFile($pfxFilename,$pfxPassword);
if ($success != 1) {
    print $cert->LastErrorText . "\n";
    exit;
}

// Get the private key...

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

// Export to various formats:

$password = 'secret';

// PKCS8 Encrypted DER
$path = '/Users/chilkat/testData/privkeys/chilkat_pkcs8_enc.der';
$success = $privKey->SavePkcs8EncryptedFile($password,$path);
if ($success != 1) {
    print $privKey->LastErrorText . "\n";

    exit;
}

// PKCS8 Encrypted PEM
$path = '/Users/chilkat/testData/privkeys/chilkat_pkcs8_enc.pem';
$success = $privKey->SavePkcs8EncryptedPemFile($password,$path);
if ($success != 1) {
    print $privKey->LastErrorText . "\n";

    exit;
}

// PKCS8 Unencrypted DER
$path = '/Users/chilkat/testData/privkeys/chilkat_pkcs8.der';
$success = $privKey->SavePkcs8File($path);
if ($success != 1) {
    print $privKey->LastErrorText . "\n";

    exit;
}

// PKCS8 Unencrypted PEM
$path = '/Users/chilkat/testData/privkeys/chilkat_pkcs8.pem';
$success = $privKey->SavePkcs8PemFile($path);
if ($success != 1) {
    print $privKey->LastErrorText . "\n";

    exit;
}

//  RSA DER (unencrypted)
$path = '/Users/chilkat/testData/privkeys/chilkat_rsa.der';
$success = $privKey->SavePkcs1File($path);
if ($success != 1) {
    print $privKey->LastErrorText . "\n";

    exit;
}

// RSA PEM (unencrypted)
$path = '/Users/chilkat/testData/privkeys/chilkat_rsa.pem';
$success = $privKey->SavePemFile($path);
if ($success != 1) {
    print $privKey->LastErrorText . "\n";

    exit;
}

// XML (unencrypted)
$path = '/Users/chilkat/testData/privkeys/chilkat.xml';
$success = $privKey->SaveXmlFile($path);
if ($success != 1) {
    print $privKey->LastErrorText . "\n";

    exit;
}

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

?>