formidable / classes / models / FrmFormState.php

FrmFormState.php in Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes & More 6.25.1, at classes/models/FrmFormState.php

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1	<?php
2
3	if ( ! defined( 'ABSPATH' ) ) {
4	die( 'You are not allowed to call this page directly.' );
5	}
6
7	/**
8	* Track form state in an encrypted form field.
9	* The state just holds some basic info, like if a [formidable] shortcode loaded
10	* with a title=1 or description=1 option.
11	*
12	* @since 6.2
13	*/
14	class FrmFormState {
15
16	/**
17	* @var FrmFormState
18	*/
19	private static $instance;
20
21	/**
22	* @var array
23	*/
24	private $state;
25
26	private function __construct() {
27	$this->state = array();
28	}
29
30	/**
31	* @param string $key
32	* @param mixed $value
33	* @return void
34	*/
35	public static function set_initial_value( $key, $value ) {
36	if ( is_callable( 'FrmProFormState::set_initial_value' ) ) {
37	// Let Pro handle state.
38	return;
39	}
40
41	self::maybe_initialize();
42	self::$instance->set( $key, $value );
43	}
44
45	/**
46	* @return bool true if just initialized.
47	*/
48	private static function maybe_initialize() {
49	if ( empty( self::$instance ) ) {
50	self::$instance = new self();
51	return true;
52	}
53	return false;
54	}
55
56	/**
57	* @param string $key
58	* @param mixed $value
59	* @return void
60	*/
61	public function set( $key, $value ) {
62	$this->state[ $key ] = $value;
63	}
64
65	/**
66	* @param string $key
67	* @param mixed $default
68	* @return mixed
69	*/
70	public static function get_from_request( $key, $default ) {
71	if ( self::maybe_initialize() ) {
72	self::get_state_from_request();
73	}
74	return self::$instance->get( $key, $default );
75	}
76
77	public function get( $key, $default ) {
78	return $this->state[ $key ] ?? $default;
79	}
80
81	/**
82	* Render a basic version of the state field from Pro.
83	* This is required only when submitting with AJAX.
84	* It is used to track the value of a title=1\|0 or description=1\|0 option in a [formidable] shortcode.
85	*
86	* @param stdClass $form
87	* @return void
88	*/
89	public static function maybe_render_state_field( $form ) {
90	if ( is_callable( 'FrmProFormState::maybe_render_state_field' ) ) {
91	// Let Pro handle state when Pro is available.
92	// This way we can also avoid duplicate state fields if Pro isn't up to date.
93	return;
94	}
95
96	if ( empty( self::$instance ) && ! self::get_state_from_request() ) {
97	return;
98	}
99
100	$honeypot_field_id = self::$instance->get( 'honeypot_field_id', 0 );
101
102	if ( empty( $form->options['ajax_submit'] ) && ! $honeypot_field_id ) {
103	// This is only required for AJAX submit, or when the honeypot field is on the page.
104	return;
105	}
106
107	$state_title = ! empty( self::$instance->state['title'] ) ? 1 : 0;
108	$state_description = ! empty( self::$instance->state['description'] ) ? 1 : 0;
109	$settings_title = ! empty( $form->options['show_title'] ) ? 1 : 0;
110	$settings_description = ! empty( $form->options['show_description'] ) ? 1 : 0;
111
112	if ( $state_title === $settings_title && $state_description === $settings_description && ! $honeypot_field_id ) {
113	// Avoid state field if it matches form settings and there is no honeypot.
114	return;
115	}
116
117	self::$instance->render_state_field();
118	}
119
120	/**
121	* @return bool true if there is valid state data in the request.
122	*/
123	private static function get_state_from_request() {
124	$encrypted_state = FrmAppHelper::get_post_param( 'frm_state', '', 'sanitize_text_field' );
125	if ( ! $encrypted_state ) {
126	return false;
127	}
128	$secret = self::get_encryption_secret();
129	$decrypted_state = openssl_decrypt( $encrypted_state, 'AES-128-ECB', $secret );
130	if ( false === $decrypted_state ) {
131	return false;
132	}
133	$decoded_state = json_decode( $decrypted_state, true );
134	if ( ! is_array( $decoded_state ) ) {
135	return false;
136	}
137	foreach ( $decoded_state as $key => $value ) {
138	self::set_initial_value( self::decompressed_key( $key ), $value );
139	}
140	return true;
141	}
142
143	/**
144	* @return void
145	*/
146	public function render_state_field() {
147	if ( ! self::open_ssl_is_installed() ) {
148	return;
149	}
150	if ( ! $this->state && ! self::get_state_from_request() ) {
151	return;
152	}
153	$state_string = $this->get_state_string();
154	echo '<input name="frm_state" type="hidden" value="' . esc_attr( $state_string ) . '" />';
155	}
156
157	/**
158	* @return string
159	*/
160	private function get_state_string() {
161	if ( ! self::open_ssl_is_installed() ) {
162	return '';
163	}
164	$secret = self::get_encryption_secret();
165	$compressed_state = $this->compressed_state();
166	$json_encoded = json_encode( $compressed_state );
167	$encrypted = openssl_encrypt( $json_encoded, 'AES-128-ECB', $secret );
168	return $encrypted;
169	}
170
171	/**
172	* Returns true if open SSL is installed.
173	*
174	* @since 6.12
175	* @return bool
176	*/
177	private static function open_ssl_is_installed() {
178	return function_exists( 'openssl_encrypt' );
179	}
180
181	/**
182	* Return state but with shorter keys to use for the state string.
183	*
184	* @return array
185	*/
186	private function compressed_state() {
187	$compressed = array();
188	foreach ( $this->state as $key => $value ) {
189	$compressed[ self::compressed_key( $key ) ] = $value;
190	}
191	return $compressed;
192	}
193
194	/**
195	* Get the first character of a key to make the option take less space.
196	* "title" => "t".
197	* "description" => "d".
198	*
199	* @param string $key
200	* @return string
201	*/
202	private static function compressed_key( $key ) {
203	return $key[0];
204	}
205
206	/**
207	* Keys are truncated to a single character to make the state string smaller.
208	* Pro supports additional keys include "i" for include_fields and "g" for get params.
209	* To avoid conflicts, we should not add "i" or "g" in Lite for another state property.
210	*
211	* @param string $key
212	* @return string The full key name if one is found. If nothing is found, the $key param is passed back.
213	*/
214	private static function decompressed_key( $key ) {
215	switch ( $key ) {
216	case 'd':
217	return 'description';
218	case 't':
219	return 'title';
220	case 'h':
221	return 'honeypot_field_id';
222	}
223	return $key;
224	}
225
226	/**
227	* @return string
228	*/
229	private static function get_encryption_secret() {
230	$secret_key = get_option( 'frm_form_state_key' );
231
232	// If we already have the secret, send it back.
233	if ( false !== $secret_key ) {
234	return base64_decode( $secret_key ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_decode
235	}
236
237	// We don't have a secret, so let's generate one.
238	$secret_key = is_callable( 'sodium_crypto_secretbox_keygen' ) ? sodium_crypto_secretbox_keygen() : wp_generate_password( 32, true, true );
239	update_option( 'frm_form_state_key', base64_encode( $secret_key ), 'no' ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_encode
240
241	return $secret_key;
242	}
243	}
244