<?php
// client.php

$serverCertificateFile = 'file://ca/certs/server.crt';
$clientPrivateKeyFile = 'file://ca/private/client.key';

$context = new ZMQContext();
$socket = $context->getSocket(ZMQ::SOCKET_REQ);
$socket->connect('ipc://magic.ipc');

$clientPrivateKey = openssl_pkey_get_private($clientPrivateKeyFile);
$serverPublicKey = openssl_pkey_get_public($serverCertificateFile);

$data = 'rolf';

openssl_public_encrypt($data, $crypted, $serverPublicKey);
openssl_sign($crypted, $signature, $clientPrivateKey);

while ($msg = openssl_error_string())
    echo $msg . "\n";

$msg = array(
    'data' => $crypted,
    'signature' => $signature,
);

$socket->send(serialize($msg));