(PHP Extension) Convert Java KeyStore to PKCS12 / PFX

Loads a Java keystore file and saves it as a PKCS12 / PFX. A Java keystore (JKS) can contain two types of entries: (1) trusted root certificates or (2) private keys + cert chains. Usually a JKS will contain all entries of one type or another (and thus a particular JKS serves one purpose or another; meaning that a JKS containing trusted roots is used as a source for verifying pre-trusted roots, and a JKS containing private keys (and cert chains) is used as a secure, encrypted store for private keys).

A PKCS12 / PFX typically contains one or more private keys, along with each private key's certificate chain. Therefore, it typically makes sense to only write the private key entries to a PKCS12 (and the associated certificate chains). If a JKS contains trusted root certificates, it makes more sense to conver it to a PEM file (such as the CA cert bundle in PEM format from mozilla.org).

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");

// This requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

$jks = new CkJavaKeyStore();

$jksPassword = 'myJksPassword';

// Load the Java keystore from a file.  The JKS file password is used
// to verify the keyed digest that is found at the very end of the keystore.
// It verifies that the keystore has not been modified.
$success = $jks->LoadFile($jksPassword,'/someDir/keyStore.jks');
if ($success != true) {
    print $jks->lastErrorText() . "\n";
    exit;
}

// To convert, we'll access the private key entries
// from the JKS, add each to the PKCS12, and then save the PKCS12.
$pkcs12 = new CkPfx();

$numPrivateKeys = $jks->get_NumPrivateKeys();

// For each private key entry, get the private key and
// the associated certificate chain.
// Each private key is password protected.  Usually it is the same
// password as used for the keyed digest of the entire JKS.  
// However, this does not have to be.  The password is passed
// here to handle the possibility of each private key requiring
// a different password.
$i = 0;
while ($i < $numPrivateKeys) {
    // privKey is a CkPrivateKey
    $privKey = $jks->GetPrivateKey($jksPassword,$i);
    print $jks->getPrivateKeyAlias($i) . "\n";
    // certChain is a CkCertChain
    $certChain = $jks->GetCertChain($i);

    // Add the private key and it's associated certificate chain to the PKCS12.
    $success = $pkcs12->AddPrivateKey($privKey,$certChain);
    if ($success != true) {
        print $pkcs12->lastErrorText() . "\n";

        exit;
    }

    $i = $i + 1;
}

// Save the PKCS12 / PFX to a file.
// The password can be the same as the JKS password, or something new.
// (With the PKCS12 format, there is a single password for the entire contents
// of the file.  With the JKS format, there is flexibility in allowing each private key
// to have it's own password.)
$pkcs12Password = 'myNewPassword';
$success = $pkcs12->ToFile($pkcs12Password,'/pkcs12_files/myPfx.p12');
if ($success != true) {
    print $pkcs12->lastErrorText() . "\n";
}
else {
    print 'Successfully saved to PKCS12 format.' . "\n";
}


?>