PHP Requires Chilkat v11.0.0+

Convert RSA Private Key to Public Key

See more RSA Examples

Demonstrates how to get a public RSA key from a private RSA key. Chilkat2 PHP

<?php

use Chilkat2\PrivateKey;
use Chilkat2\PublicKey;

$privKey = new PrivateKey();

// Step 1: Load the private key from a source.
// (Chilkat can load private keys from all types of formats, and from in-memory bytes or encoded strings.
// see the online reference documentation for more options.)
try {
    $privKey->LoadPemFile('qa_data/pem/VP_Private.pem');

    // Step 2: Get the public key object from the private key object.
    $pubKey = new PublicKey();
    $privKey->ToPublicKey($pubKey);

    // Step 3: Save the public key in a desired format.
    // (Chilkat can load or save public and private keys in many different formats.  See
    // the online reference documentation for more options.)

    // Saves to a PKCS8 PEM file.
    $bPreferPkcs1 = false;
    $pubKey->SavePemFile($bPreferPkcs1, 'qa_data/pem/VP_Public.pem');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo "Extracted and saved public key from private key.\n";