<?php
/**
 * This file was developed by Nathan <[email protected]>
 *
 * Created:     nathan - 18 May 2010 13:20:39
 * Modified:    SVN: $Id$
 * PHP Version: 5.1.6+
 *
 * @package   @project.name@
 * @author    Nathan <[email protected]>
 * @version   SVN: $Revision$
 */

class ApplicationCrypto
{
    /**
     *
     * @var ApplicationCrypto
     */
    private static $__instance;

    private $certificate;

    private $privateKey;

    private $publicKey;

    protected function __construct()
    {

    }

    public function seal( $data )
    {
        openssl_seal( $data , $sealed , $encryptedKeys , array($this->publicKey) );
        return (object)array(
            'sealed' => bin2hex($sealed),
            'key' => bin2hex($encryptedKeys[0]),
        );
    }

    public function open( $sealed , $key )
    {
        openssl_open( pack("H*" , $sealed) , $opened , pack("H*" , $key) , $this->privateKey );
        return $opened;
    }

    /**
     *
     * @param $applicationPKCS12
     * @param $password
     * @return ApplicationCrypto
     */
    public static function instantiate( $applicationPKCS12 , $password )
    {
        if( !file_exists($applicationPKCS12) ) {
            throw new InvalidArgumentException( 'The specified Application PKCS12 does not exist.');
        }
        $pkcs12 = file_get_contents( $applicationPKCS12 );
        if( openssl_pkcs12_read( $pkcs12 , $exported , $password ) === FALSE ) {
            throw new UnexpectedValueException( 'The specified Application PKCS12 could not be read by the system.' );
        }
        if( !isset( $exported['cert'] , $exported['pkey'] ) ) {
            throw new UnexpectedValueException( 'The specified Application PKCS12 did not contain a certificate and a private key.' );
        }

        $public_key = openssl_pkey_get_details(
            openssl_pkey_get_private( $exported['pkey'] )
        );

        $applicationCrypto = new self;
        $applicationCrypto->certificate = $exported['cert'];
        $applicationCrypto->privateKey = $exported['pkey'];
        $applicationCrypto->publicKey = $public_key['key'];

        self::$__instance = $applicationCrypto;
        return self::getInstance();
    }

    /**
     *
     * @return ApplicationCrypto
     */
    public static function getInstance()
    {
        if( !(self::$__instance instanceof ApplicationCrypto) ) {
            throw new UnexpectedValueException( 'ApplicationCrypto has not been instantiated with a PKCS12' );
        }
        return self::$__instance;
    }
}