Encryption_Utility.php — WooCommerce Square 4.5.0

woocommerce-square / includes / Utilities / Encryption_Utility.php

woocommerce-square / includes / Utilities Last commit date

Array_Utility.php 3 years ago Encryption_Utility.php 3 years ago Helper.php 3 years ago Money_Utility.php 3 years ago String_Utility.php 3 years ago

Encryption_Utility.php

267 lines

1	<?php
2	/**
3	* WooCommerce Square
4	*
5	* This source file is subject to the GNU General Public License v3.0
6	* that is bundled with this package in the file license.txt.
7	* It is also available through the world-wide-web at this URL:
8	* http://www.gnu.org/licenses/gpl-3.0.html GNU General Public License v3.0 or later
9	* If you did not receive a copy of the license and are unable to
10	* obtain it through the world-wide-web, please send an email
11	* to license@woocommerce.com so we can send you a copy immediately.
12	*
13	* DISCLAIMER
14	*
15	* Do not edit or add to this file if you wish to upgrade WooCommerce Square to newer
16	* versions in the future. If you wish to customize WooCommerce Square for your
17	* needs please refer to https://docs.woocommerce.com/document/woocommerce-square/
18	*
19	* @author WooCommerce
20	* @copyright Copyright: (c) 2019, Automattic, Inc.
21	* @license http://www.gnu.org/licenses/gpl-3.0.html GNU General Public License v3.0 or later
22	*/
23
24	namespace WooCommerce\Square\Utilities;
25
26	use WooCommerce_Square_Loader;
27
28	defined( 'ABSPATH' ) \|\| exit;
29
30	/**
31	* The encryption utility class.
32	*
33	* Requires OpenSSL by default.
34	*
35	* @since 2.0.0
36	*/
37	class Encryption_Utility {
38
39
40	/** @var string default cipher method */
41	protected $default_cipher_method = 'AES-128-CBC';
42
43	/** @var string cipher method */
44	protected $cipher_method;
45
46
47	/**
48	* Constructs the class.
49	*
50	* @param string $preferred_cipher_method cipher method
51	*/
52	public function __construct( $preferred_cipher_method = '' ) {
53
54	// bail entirely if openssl isn't available
55	if ( ! self::is_encryption_supported() ) {
56	wc_doing_it_wrong( __CLASS__, __( 'Encryption is not supported on this site.', 'woocommerce-square' ), WooCommerce_Square_Loader::FRAMEWORK_VERSION );
57	return;
58	}
59
60	$this->cipher_method = $this->get_default_cipher_method();
61
62	// if a preferred cipher method is set, check and set it
63	if ( is_string( $preferred_cipher_method ) && ! empty( $preferred_cipher_method ) ) {
64
65	// only use what's preferred if it's supported
66	if ( $this->is_cipher_method_supported( $preferred_cipher_method ) ) {
67
68	$this->cipher_method = $preferred_cipher_method;
69
70	} else { // otherwise, throw a notice and continue with the default
71
72	$message = sprintf(
73	/* translators: %1$s - Cipher method. %2$s - Preferred cipher method. */
74	__( '%1$s encryption is not available on this site. %2$s will be used instead.', 'woocommerce-square' ),
75	$preferred_cipher_method,
76	$this->cipher_method
77	);
78
79	wc_doing_it_wrong( __CLASS__, $message, WooCommerce_Square_Loader::FRAMEWORK_VERSION );
80	}
81	}
82	}
83
84
85	/**
86	* Encrypts data.
87	*
88	* @since 2.0.0
89	*
90	* @param string\|array $data data to encrypt
91	* @param string $key encryption key
92	* @return string
93	* @throws \Exception
94	*/
95	public function encrypt_data( $data, $key = '' ) {
96
97	// sanity check to ensure encryption can happen
98	if ( ! $this->get_cipher_method() ) {
99	throw new \Exception( __( 'No encryption method available', 'woocommerce-square' ) );
100	}
101
102	if ( empty( $data ) \|\| ( ! is_string( $data ) && ! is_array( $data ) ) ) {
103	throw new \Exception( __( 'Data must be a non-empty string or array', 'woocommerce-square' ) );
104	}
105
106	if ( ! is_string( $key ) ) {
107	throw new \Exception( __( 'Encryption key must be a string', 'woocommerce-square' ) );
108	}
109
110	// default to the WP salt
111	if ( empty( $key ) ) {
112	$key = $this->get_default_key();
113	}
114
115	$vector = openssl_random_pseudo_bytes( $this->get_vector_length(), $crypto_strong );
116
117	// bail if a strong vector wasn't generated
118	if ( false === $vector \|\| false === $crypto_strong ) {
119	throw new \Exception( __( 'Could not generate encryption vector.', 'woocommerce-square' ) );
120	}
121
122	$encrypted_data = openssl_encrypt( wp_json_encode( $data ), $this->get_cipher_method(), $key, 0, $vector );
123
124	return base64_encode( $vector . $encrypted_data );
125	}
126
127
128	/**
129	* Decrypts data.
130	*
131	* @since 2.0.0
132	*
133	* @param string $data data to decrypt
134	* @param string $key decryption key
135	* @return string\|array
136	* @throws \Exception
137	*/
138	public function decrypt_data( $data, $key = '' ) {
139
140	// sanity check to ensure decryption can happen
141	if ( ! $this->get_cipher_method() ) {
142	throw new \Exception( __( 'No decryption method available', 'woocommerce-square' ) );
143	}
144
145	if ( empty( $data ) \|\| ! is_string( $data ) ) {
146	throw new \Exception( __( 'Data must be a non-empty string', 'woocommerce-square' ) );
147	}
148
149	if ( ! is_string( $key ) ) {
150	throw new \Exception( __( 'Encryption key must be a string', 'woocommerce-square' ) );
151	}
152
153	// default to the WP salt
154	if ( empty( $key ) ) {
155	$key = $this->get_default_key();
156	}
157
158	$data = base64_decode( $data );
159
160	$vector_length = $this->get_vector_length();
161	$vector = substr( $data, 0, $vector_length );
162	$data = substr( $data, $vector_length );
163	$data = openssl_decrypt( $data, $this->get_cipher_method(), $key, 0, $vector );
164
165	return json_decode( $data, true );
166	}
167
168
169	/**
170	* Gets the vector length.
171	*
172	* @since 2.0.0
173	*
174	* @return int
175	*/
176	protected function get_vector_length() {
177
178	return openssl_cipher_iv_length( $this->get_cipher_method() );
179	}
180
181
182	/**
183	* Determines if a cipher method is supported by the server.
184	*
185	* @since 2.0.0
186	*
187	* @param string $method cipher method to check
188	* @return bool
189	*/
190	protected function is_cipher_method_supported( $method ) {
191
192	return in_array( $method, $this->get_supported_cipher_methods(), true );
193	}
194
195
196	/**
197	* Determines if encryption is supported at all.
198	*
199	* @since 2.0.0
200	*
201	* @return bool
202	*/
203	public static function is_encryption_supported() {
204
205	return extension_loaded( 'openssl' );
206	}
207
208
209	/**
210	* Gets the cipher method.
211	*
212	* @since 2.0.0
213	*
214	* @return string
215	*/
216	protected function get_cipher_method() {
217
218	return $this->cipher_method;
219	}
220
221
222	/**
223	* Gets the default cipher method.
224	*
225	* Checks the list of supported methods first, and if the default isn't supported, uses the first available.
226	*
227	* @since 2.0.0
228	*
229	* @return string
230	*/
231	protected function get_default_cipher_method() {
232
233	$available_methods = $this->get_supported_cipher_methods();
234
235	return in_array( $this->default_cipher_method, $available_methods, true ) ? $this->default_cipher_method : $available_methods[0];
236	}
237
238
239	/**
240	* Gets the supported cipher methods.
241	*
242	* @since 2.0.0
243	*
244	* @return array
245	*/
246	protected function get_supported_cipher_methods() {
247
248	return openssl_get_cipher_methods();
249	}
250
251
252	/**
253	* Gets the default encryption key.
254	*
255	* @since 2.0.0
256	*
257	* @return string
258	*/
259	protected function get_default_key() {
260	if ( wc_square()->get_settings_handler()->is_custom_square_auth_keys_set() ) {
261	return md5( SQUARE_ENCRYPTION_KEY . SQUARE_ENCRYPTION_SALT );
262	}
263
264	return md5( wp_salt(), true );
265	}
266	}
267