ci4

1
<?php
2

3
declare(strict_types=1);
4

5
/**
6
 * This file is part of CodeIgniter 4 framework.
7
 *
8
 * (c) CodeIgniter Foundation <admin@codeigniter.com>
9
 *
10
 * For the full copyright and license information, please view
11
 * the LICENSE file that was distributed with this source code.
12
 */
13

14
namespace CodeIgniter\Encryption;
15

16
use CodeIgniter\Encryption\Exceptions\EncryptionException;
17
use Config\Encryption as EncryptionConfig;
18

19
/**
20
 * CodeIgniter Encryption Manager
21
 *
22
 * Provides two-way keyed encryption via PHP's Sodium and/or OpenSSL extensions.
23
 * This class determines the driver, cipher, and mode to use, and then
24
 * initializes the appropriate encryption handler.
25
 *
26
 * @see \CodeIgniter\Encryption\EncryptionTest
27
 */
28
class Encryption
29
{
30
    /**
31
     * The encrypter we create
32
     *
33
     * @var EncrypterInterface
34
     */
35
    protected $encrypter;
36

37
    /**
38
     * The driver being used
39
     *
40
     * @var string
41
     */
42
    protected $driver;
43

44
    /**
45
     * The key/seed being used
46
     *
47
     * @var string
48
     */
49
    protected $key;
50

51
    /**
52
     * The derived HMAC key
53
     *
54
     * @var string
55
     */
56
    protected $hmacKey;
57

58
    /**
59
     * HMAC digest to use
60
     *
61
     * @var string
62
     */
63
    protected $digest = 'SHA512';
64

65
    /**
66
     * Map of drivers to handler classes, in preference order
67
     *
68
     * @var array
69
     */
70
    protected $drivers = [
71
        'OpenSSL',
72
        'Sodium',
73
    ];
74

75
    /**
76
     * Handlers that are to be installed
77
     *
78
     * @var array<string, bool>
79
     */
80
    protected $handlers = [];
81

82
    /**
83
     * @throws EncryptionException
84
     */
85
    public function __construct(?EncryptionConfig $config = null)
86
    {
87
        $config ??= new EncryptionConfig();
88

89
        $this->key    = $config->key;
90
        $this->driver = $config->driver;
91
        $this->digest = $config->digest ?? 'SHA512';
92

93
        $this->handlers = [
94
            'OpenSSL' => extension_loaded('openssl'),
95
            // the SodiumHandler uses some API (like sodium_pad) that is available only on v1.0.14+
96
            'Sodium' => extension_loaded('sodium') && version_compare(SODIUM_LIBRARY_VERSION, '1.0.14', '>='),
97
        ];
98

99
        if (! in_array($this->driver, $this->drivers, true) || (array_key_exists($this->driver, $this->handlers) && ! $this->handlers[$this->driver])) {
100
            throw EncryptionException::forNoHandlerAvailable($this->driver);
101
        }
102
    }
103

104
    /**
105
     * Initialize or re-initialize an encrypter
106
     *
107
     * @return EncrypterInterface
108
     *
109
     * @throws EncryptionException
110
     */
111
    public function initialize(?EncryptionConfig $config = null)
112
    {
113
        if ($config instanceof EncryptionConfig) {
114
            $this->key    = $config->key;
115
            $this->driver = $config->driver;
116
            $this->digest = $config->digest ?? 'SHA512';
117
        }
118

119
        if (empty($this->driver)) {
120
            throw EncryptionException::forNoDriverRequested();
121
        }
122

123
        if (! in_array($this->driver, $this->drivers, true)) {
124
            throw EncryptionException::forUnKnownHandler($this->driver);
125
        }
126

127
        if (empty($this->key)) {
128
            throw EncryptionException::forNeedsStarterKey();
129
        }
130

131
        $this->hmacKey = bin2hex(\hash_hkdf($this->digest, $this->key));
132

133
        $handlerName     = 'CodeIgniter\\Encryption\\Handlers\\' . $this->driver . 'Handler';
134
        $this->encrypter = new $handlerName($config);
135

136
        return $this->encrypter;
137
    }
138

139
    /**
140
     * Create a random key
141
     *
142
     * @param int $length Output length
143
     *
144
     * @return string
145
     */
146
    public static function createKey($length = 32)
147
    {
148
        return random_bytes($length);
149
    }
150

151
    /**
152
     * __get() magic, providing readonly access to some of our protected properties
153
     *
154
     * @param string $key Property name
155
     *
156
     * @return array|string|null
157
     */
158
    public function __get($key)
159
    {
160
        if ($this->__isset($key)) {
161
            return $this->{$key};
162
        }
163

164
        return null;
165
    }
166

167
    /**
168
     * __isset() magic, providing checking for some of our protected properties
169
     *
170
     * @param string $key Property name
171
     */
172
    public function __isset($key): bool
173
    {
174
        return in_array($key, ['key', 'digest', 'driver', 'drivers'], true);
175
    }
176
}
177