3kJdKC4h

1<?php
2/**
3 * Cookie-Stored session class.
4 */
5class cookie_stored_session
6{
7    const cookie_max_length = 4096;
8    protected $_secret_key;
9    protected $_vars = array();
10    protected $_available = false;
11    protected $_cookie_name;
12    protected $_cookie_params;
13
14    public function __construct($secret_key)
15    {
16        $this->_secret_key = $secret_key;
17        $this->_available = true;
18        // use session settings
19        $this->_cookie_name = session_name();
20        $this->_cookie_params = session_get_cookie_params();
21        $this->_restore();
22    }
23
24    public function __destruct()
25    {
26        if ($this->_available) {
27            $this->_save();
28        }
29    }
30
31    public function __set($name, $value)
32    {
33        $this->_vars[$name] = $value;
34    }
35
36    public function __get($name)
37    {
38        if (isset($this->_vars[$name])) {
39            return $this->_vars[$name];
40        }
41        return null;
42    }
43
44    public function __isset($name)
45    {
46        return isset($this->_vars[$name]);
47    }
48
49    public function __unset($name)
50    {
51        if (isset($this->_vars[$name])) {
52            unset($this->_vars[$name]);
53        }
54    }
55
56    public function lifetime($seconds)
57    {
58        $this->_cookie_params['lifetime'] = $seconds;
59    }
60
61    public function destroy()
62    {
63        $this->_available = false;
64        $this->_vars = array();
65        $this->_cookie('', time() - 3600);
66    }
67
68    protected function _restore()
69    {
70        if (!isset($_COOKIE[$this->_cookie_name])) {
71            // cookie not exists
72            return;
73        }
74        $cookie_data = $_COOKIE[$this->_cookie_name];
75        $data_list = explode('--', $cookie_data);
76        if (count($data_list) !== 2) {
77            // invalid cookie value
78            $this->destroy();
79            return;
80        }
81        $vars = @unserialize(base64_decode($data_list[0]));
82        if ($vars === false || !is_array($vars)) {
83            // broken cookie value
84            $this->destroy();
85            return;
86        }
87        if ($this->_digest($vars) !== $data_list[1]) {
88            // tampered
89            $this->destroy();
90            return;
91        }
92        $this->_vars = $vars;
93    }
94
95    protected function _save()
96    {
97        $expire = time() + $this->_cookie_params['lifetime'];
98        $digest = $this->_digest($this->_vars);
99        $cookie_data = base64_encode(serialize($this->_vars)) . '--' . $digest;
100
101        if (strlen($cookie_data) > self::cookie_max_length) {
102            throw new Exception('session data is too large');
103        }
104
105        $this->_cookie($cookie_data, $expire);
106    }
107
108    protected function _digest($data)
109    {
110        $serialized_data = serialize($data);
111        return hash_hmac('sha1', $serialized_data, $this->_secret_key);
112    }
113
114    protected function _cookie($value, $expire)
115    {
116        $name = $this->_cookie_name;
117        $params = $this->_cookie_params;
118
119        if (empty($params['domain']) && empty($params['secure'])) {
120            setcookie($name, $value, $expire, $params['path']);
121        } else if (empty($params['secure'])) {
122            setcookie($name, $value, $expire,
123                $params['path'], $params['domain']);
124        } else {
125            setcookie($name, $value, $expire,
126               $params['path'], $params['domain'], $params['secure']);
127        }
128    }
129}