PHP

Export a Public Key as a JWK

Demonstrates the Chilkat PublicKey.GetJwk method, which returns the public key as a compact JWK (JSON Web Key). It takes no arguments; binary values use Base64url without padding and the member order is stable across calls.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: JWK is the JSON key format used across modern web security — JWT, OAuth, OpenID Connect. Exporting a public key to JWK is exactly what you do to publish it in a JWK Set (a jwks_uri endpoint) so others can verify your signatures. The stable member order matters because it makes the output reproducible, which is important when the JWK feeds into a thumbprint.

Chilkat PHP Downloads

Download Chilkat for PHP

Chilkat2 PHP

<?php

use Chilkat2\PublicKey;

// Load a public key to export.  LoadFromFile inspects the content, so it accepts DER, PEM, XML,
// JWK, and other supported representations.
$pubKey = new PublicKey();
try {
    $pubKey->LoadFromFile('qa_data/public.pem');

    // Export the public key as a compact JWK (JSON Web Key).  Binary values use Base64url without
    // padding, and the member order is stable across calls.
    $jwk = $pubKey->GetJwk();
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo $jwk, "\n";