cookied_session.php

<?php

ini_set('session.gc_probability', 0);
ini_set('session.cookie_domain', '.plantarium.ru');
session_set_cookie_params(pow(2, 31) - 1, '/', '.plantarium.ru');

define('COOKIED_SESSION_COOKIE_NAME', 'cookied_session');
define('COOKIED_SESSION_KEY',
    pack('H*', '8c355bad1cfb778eacf3627511c5a345d6c2705739dff770f844893f2e05cae3'));

function base64url_encode($data) {
    return strtr(base64_encode($data), array('+' => '-', '/' => '_'));
}

function base64url_decode($data) {
    return base64_decode(strtr($data, array('-' => '+', '_' => '/')));
}

class AES {
    private $td;
    private $key;
    
    public function AES($key) {
        $this->td = mcrypt_module_open('rijndael-256', '', 'cbc', '');
        $this->key = substr($key, 0, mcrypt_enc_get_key_size($this->td));
    }
    
    private function init($iv) {
        return @mcrypt_generic_init($this->td, $this->key, $iv) != -1;
    }

    public function encrypt($plaintext) {
        $iv_size = mcrypt_enc_get_iv_size($this->td);
        $iv = mcrypt_create_iv($iv_size, MCRYPT_DEV_URANDOM);
        if (!$this->init($iv)) return false;
        
        $ciphertext = mcrypt_generic($this->td, $plaintext . "\xFF");
        mcrypt_generic_deinit($this->td);
        
        return chr($iv_size) . $iv . $ciphertext;
    }

    public function decrypt($data) {
        $iv_size = ord(substr($data, 0, 1));
        $iv = substr($data, 1, $iv_size);
        if (!$this->init($iv)) return false;
        
        $ciphertext = substr($data, $iv_size + 1);
        $plaintext = @mdecrypt_generic($this->td, $ciphertext);
        $plaintext = substr(rtrim($plaintext, "\0"), 0, -1);
        mcrypt_generic_deinit($this->td);

        return $plaintext;
    }
}

$cookied_session_cipher = new AES(COOKIED_SESSION_KEY);

function cookied_session_read($id) {
    global $cookied_session_cipher;
    if (!isset($_COOKIE[COOKIED_SESSION_COOKIE_NAME])) {
        return '';
    }
    $sess_data = base64url_decode($_COOKIE[COOKIED_SESSION_COOKIE_NAME]);
    $sess_data = bzdecompress($cookied_session_cipher->decrypt($sess_data));
    if ($sess_data < 0) return '';
    return $sess_data;
}

function cookied_session_write($id, $sess_data) {
    global $cookied_session_cipher;
    $value = base64url_encode($cookied_session_cipher->encrypt(bzcompress($sess_data)));
    $params = session_get_cookie_params();
    setcookie(COOKIED_SESSION_COOKIE_NAME, $value, $params['lifetime'],
        $params['path'], $params['domain'], $params['secure'], $params['httponly']);
    return true;
}

function cookied_session_destroy($id) {
    setcookie(COOKIED_SESSION_COOKIE_NAME, '', time() - 60 * 60 * 24);
    return true;
}

function cookied_session_noop() { return true; }

session_set_save_handler(
    'cookied_session_noop',
    'cookied_session_noop',
    'cookied_session_read',
    'cookied_session_write',
    'cookied_session_destroy',
    'cookied_session_noop'
);