wplingua / inc / encryption.php

encryption.php in Translate and Go multilingual – Automatic AI translation – wpLingua trunk, at inc/encryption.php

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1	<?php
2
3	// If this file is called directly, abort.
4	if ( ! defined( 'WPINC' ) ) {
5	die;
6	}
7
8
9	/**
10	* Get the encryption key for AES-256-GCM.
11	*
12	* Retrieves the encryption key from the database. If it doesn't exist,
13	* generates a new 256-bit random key and stores it.
14	*
15	* @return string The raw binary encryption key.
16	*/
17	function wplng_encryption_get_key() {
18
19	$option_name = 'wplng_encryption_key';
20
21	// Try to retrieve the key from the database stored in an option
22	$encryption_key = get_option( $option_name );
23
24	// If the key doesn't exist, create one randomly and store it
25	if ( empty( $encryption_key ) ) {
26	$encryption_key = base64_encode( random_bytes( 32 ) ); // 256 bits
27	update_option( $option_name, $encryption_key, false );
28	}
29
30	return base64_decode( $encryption_key );
31	}
32
33
34	/**
35	* Encrypt a text using AES-256-GCM.
36	*
37	* Encrypts the given text using AES-256-GCM symmetric encryption.
38	* The result includes the IV and authentication tag for decryption.
39	*
40	* @param string $text The plain text to encrypt.
41	* @return string The encrypted text encoded in base64, or empty string on failure.
42	*/
43	function wplng_encryption_encrypt( $text ) {
44
45	if ( empty( $text ) ) {
46	return '';
47	}
48
49	$method = 'aes-256-gcm';
50	$key = wplng_encryption_get_key();
51
52	// Generate a random IV (initialization vector)
53	$iv_length = openssl_cipher_iv_length( $method );
54
55	if ( false === $iv_length ) {
56	return '';
57	}
58
59	$iv = random_bytes( $iv_length );
60
61	// Encrypt the text with AES-256-GCM
62	$tag = '';
63	$encrypted = openssl_encrypt(
64	$text,
65	$method,
66	$key,
67	OPENSSL_RAW_DATA,
68	$iv,
69	$tag,
70	'',
71	16 // Authentication tag length
72	);
73
74	if ( $encrypted === false ) {
75	return '';
76	}
77
78	// Combine IV + tag + encrypted text and encode in base64
79	$encrypted_text = base64_encode( $iv . $tag . $encrypted );
80
81	return $encrypted_text;
82	}
83
84
85	/**
86	* Decrypt a text encrypted with AES-256-GCM.
87	*
88	* Decrypts the given base64-encoded text that was encrypted
89	* using the wplng_encryption_encrypt function.
90	*
91	* @param string $text The encrypted text encoded in base64.
92	* @return string The decrypted plain text, or empty string on failure.
93	*/
94	function wplng_encryption_decrypt( $text ) {
95
96	if ( empty( $text ) ) {
97	return '';
98	}
99
100	$method = 'aes-256-gcm';
101	$key = wplng_encryption_get_key();
102
103	// Decode the text from base64
104	$data = base64_decode( $text );
105
106	if ( $data === false ) {
107	return '';
108	}
109
110	// Extract the IV, tag and encrypted text
111	$iv_length = openssl_cipher_iv_length( $method );
112
113	if ( false === $iv_length
114	\|\| strlen( $data ) < $iv_length + 16 + 1
115	) {
116	return '';
117	}
118
119	$iv = substr( $data, 0, $iv_length );
120	$tag = substr( $data, $iv_length, 16 );
121	$encrypted = substr( $data, $iv_length + 16 );
122
123	// Decrypt the text
124	$decrypted_text = openssl_decrypt(
125	$encrypted,
126	$method,
127	$key,
128	OPENSSL_RAW_DATA,
129	$iv,
130	$tag
131	);
132
133	if ( $decrypted_text === false ) {
134	return '';
135	}
136
137	return $decrypted_text;
138	}
139