create ssh rsa keys .php

<?php
// install composer require phpseclib/phpseclib:~2.0
// https://github.com/phpseclib/phpseclib

        $rsa = new \phpseclib\Crypt\RSA();
        $rsa->setPassword($password);
        $rsa->setPrivateKeyFormat(\phpseclib\Crypt\RSA::PUBLIC_FORMAT_OPENSSH);
        $rsa->setPublicKeyFormat(\phpseclib\Crypt\RSA::PUBLIC_FORMAT_OPENSSH);
        $rsa->setComment('robot@laravel.com');
        $keys = $rsa->createKey(4096);
        $publicKey = $keys['publickey'];
        $privateKey = $keys['privatekey'];