formidable / classes / models / FrmAntiSpam.php

FrmAntiSpam.php in Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes & More 6.21, at classes/models/FrmAntiSpam.php

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1	<?php
2	if ( ! defined( 'ABSPATH' ) ) {
3	die( 'You are not allowed to call this page directly.' );
4	}
5
6	/**
7	* Class FrmAntiSpam.
8	*
9	* This token class generates tokens that are used in our Anti-Spam checking.
10	*
11	* @since 4.11
12	*/
13	class FrmAntiSpam extends FrmValidate {
14
15	/**
16	* @return string
17	*/
18	protected function get_option_key() {
19	return 'antispam';
20	}
21
22	/**
23	* @param int $form_id
24	*
25	* @return void
26	*/
27	public static function maybe_init( $form_id ) {
28	$antispam = new self( $form_id );
29	if ( $antispam->run_antispam() ) {
30	$antispam->init();
31	}
32	}
33
34	/**
35	* Initialise the actions for the Anti-spam.
36	*
37	* @since 4.11
38	*
39	* @return void
40	*/
41	public function init() {
42	add_filter( 'frm_form_attributes', array( $this, 'add_token_to_form' ), 10, 1 );
43	add_filter( 'frm_form_div_attributes', array( $this, 'add_token_to_form' ), 10, 1 );
44	}
45
46	/**
47	* Return a valid token.
48	*
49	* @since 4.11
50	*
51	* @param mixed $current True to use current time, otherwise a timestamp string.
52	*
53	* @return string Token.
54	*/
55	private function get( $current = true ) {
56	// If $current was not passed, or it is true, we use the current timestamp.
57	// If $current was passed in as a string, we'll use that passed in timestamp.
58	if ( $current !== true ) {
59	$time = $current;
60	} else {
61	$time = time();
62	}
63
64	// Format the timestamp to be less exact, as we want to deal in days.
65	// June 19th, 2020 would get formatted as: 1906202017125.
66	// Day of the month, month number, year, day number of the year, week number of the year.
67	$token_date = gmdate( 'dmYzW', $time );
68
69	// Combine our token date and our token salt, and md5 it.
70	$form_token_string = md5( $token_date . $this->get_antispam_secret_key() );
71
72	return $form_token_string;
73	}
74
75	private function get_antispam_secret_key() {
76	$secret_key = get_option( 'frm_antispam_secret_key' );
77
78	// If we already have the secret, send it back.
79	if ( false !== $secret_key ) {
80	return base64_decode( $secret_key ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_decode
81	}
82
83	// We don't have a secret, so let's generate one.
84	$secret_key = is_callable( 'sodium_crypto_secretbox_keygen' ) ? sodium_crypto_secretbox_keygen() : wp_generate_password( 32, true, true );
85	add_option( 'frm_antispam_secret_key', base64_encode( $secret_key ) ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_encode
86
87	return $secret_key;
88	}
89
90	/**
91	* Generate the array of valid tokens to check for. These include two days
92	* before the current date to account for long cache times.
93	*
94	* These two filters are available if a user wants to extend the times.
95	* 'frm_form_token_check_before_today'
96	* 'frm_form_token_check_after_today'
97	*
98	* @since 4.11
99	*
100	* @return array Array of all valid tokens to check against.
101	*/
102	private function get_valid_tokens() {
103	$current_date = time();
104
105	// Create our array of times to check before today. A user with a longer
106	// cache time can extend this. A user with a shorter cache time can remove times.
107	$valid_token_times_before = apply_filters(
108	'frm_form_token_check_before_today',
109	array(
110	// Two days ago.
111	2 * DAY_IN_SECONDS,
112	// One day ago.
113	1 * DAY_IN_SECONDS,
114	)
115	);
116
117	// Mostly to catch edge cases like the form page loading and submitting on two different days.
118	// This probably won't be filtered by users too much, but they could extend it.
119	$valid_token_times_after = apply_filters(
120	'frm_form_token_check_after_today',
121	array(
122	// Add in 45 minutes past today to catch some midnight edge cases.
123	45 * MINUTE_IN_SECONDS,
124	)
125	);
126
127	// Built up our valid tokens.
128	$valid_tokens = array();
129
130	// Add in all the previous times we check.
131	foreach ( $valid_token_times_before as $time ) {
132	$valid_tokens[] = $this->get( $current_date - $time );
133	}
134
135	// Add in our current date.
136	$valid_tokens[] = $this->get( $current_date );
137
138	// Add in the times after our check.
139	foreach ( $valid_token_times_after as $time ) {
140	$valid_tokens[] = $this->get( $current_date + $time );
141	}
142
143	return $valid_tokens;
144	}
145
146	/**
147	* Check if the given token is valid or not.
148	*
149	* Tokens are valid for some period of time (see frm_token_validity_in_hours
150	* and frm_token_validity_in_days to extend the validation period).
151	* By default tokens are valid for day.
152	*
153	* @since 4.11
154	*
155	* @param string $token Token to validate.
156	*
157	* @return bool Whether the token is valid or not.
158	*/
159	private function verify( $token ) {
160	// Check to see if our token is inside of the valid tokens.
161	return in_array( $token, $this->get_valid_tokens(), true );
162	}
163
164	/**
165	* Add the token field to the form.
166	*
167	* @since 4.11
168	*
169	* @param string $attributes
170	*
171	* @return string
172	*/
173	public function add_token_to_form( $attributes ) {
174	$attributes .= ' data-token="' . esc_attr( $this->get() ) . '"';
175	return $attributes;
176	}
177
178	/**
179	* @param int $form_id
180	*
181	* @return void
182	*/
183	public static function maybe_echo_token( $form_id ) {
184	$antispam = new self( $form_id );
185	if ( $antispam->run_antispam() ) {
186	echo 'data-token="' . esc_attr( $antispam->get() ) . '"';
187	}
188	}
189
190	/**
191	* @return bool
192	*/
193	public function run_antispam() {
194	return $this->is_option_on() && apply_filters( 'frm_run_antispam', true, $this->form_id );
195	}
196
197	/**
198	* Validate Anti-spam if enabled.
199	*
200	* @since 4.11
201	*
202	* @return bool\|string True or a string with the error.
203	*/
204	public function validate() {
205	if ( ! $this->run_antispam() ) {
206	return true;
207	}
208
209	$token = FrmAppHelper::get_param( 'antispam_token', '', 'post', 'sanitize_text_field' );
210
211	// If the antispam setting is enabled and we don't have a token, bail.
212	if ( ! $token ) {
213	if ( FrmAppHelper::is_admin_page( 'formidable-entries' ) ) {
214	// add an exception for the entries page.
215	return true;
216	}
217	return $this->process_antispam_filter( $this->get_missing_token_message() );
218	}
219
220	// Verify the token.
221	if ( ! $this->verify( $token ) ) {
222	return $this->process_antispam_filter( $this->get_invalid_token_message() );
223	}
224
225	return $this->process_antispam_filter( true );
226	}
227
228	/**
229	* Helper to run our filter on all the responses for the antispam checks.
230	*
231	* @since 4.11
232	*
233	* @param bool\|string $is_valid Is valid entry or not.
234	*
235	* @return bool\|string Is valid or message.
236	*/
237	private function process_antispam_filter( $is_valid ) {
238	return apply_filters( 'frm_process_antispam', $is_valid );
239	}
240
241	/**
242	* Helper to get the missing token message.
243	*
244	* @since 4.11
245	*
246	* @return string missing token message.
247	*/
248	private function get_missing_token_message() {
249	return esc_html__( 'This page isn\'t loading JavaScript properly, and the form will not be able to submit.', 'formidable' ) . $this->maybe_get_support_text();
250	}
251
252	/**
253	* Helper to get the invalid token message.
254	*
255	* @since 4.11
256	*
257	* @return string Invalid token message.
258	*/
259	private function get_invalid_token_message() {
260	return esc_html__( 'Form token is invalid. Please refresh the page.', 'formidable' ) . $this->maybe_get_support_text();
261	}
262
263	/**
264	* If a user is a super admin, add a support link to the message.
265	*
266	* @since 4.11
267	*
268	* @return string Support text if super admin, empty string if not.
269	*/
270	private function maybe_get_support_text() {
271	// If user isn't a super admin, don't return any text.
272	if ( ! is_super_admin() ) {
273	return '';
274	}
275
276	// If the user is an admin, return text with a link to support.
277	// We add a space here to separate the sentences, but outside of the localized
278	// text to avoid it being removed.
279	return ' ' . sprintf(
280	// translators: %1$s start link, %2$s end link.
281	esc_html__( 'Please check out our %1$stroubleshooting guide%2$s for details on resolving this issue.', 'formidable' ),
282	'<a href="https://formidableforms.com/knowledgebase/add-spam-protection/">',
283	'</a>'
284	);
285	}
286
287	/**
288	* Clear third party cache plugins to avoid data-tokens missing or appearing when the antispam setting is changed.
289	*
290	* @return void
291	*/
292	public static function clear_caches() {
293	self::clear_w3_total_cache();
294	self::clear_wp_fastest_cache();
295	self::clear_wp_super_cache();
296	self::clear_wp_optimize();
297	}
298
299	/**
300	* @return void
301	*/
302	private static function clear_w3_total_cache() {
303	if ( is_callable( 'w3tc_flush_all' ) ) {
304	w3tc_flush_all();
305	}
306	}
307
308	/**
309	* @return void
310	*/
311	private static function clear_wp_fastest_cache() {
312	do_action( 'wpfc_clear_all_cache' );
313	}
314
315	/**
316	* @return void
317	*/
318	private static function clear_wp_super_cache() {
319	if ( function_exists( 'wp_cache_clean_cache' ) ) {
320	global $file_prefix;
321	wp_cache_clean_cache( $file_prefix, true );
322	}
323	}
324
325	/**
326	* @return void
327	*/
328	private static function clear_wp_optimize() {
329	if ( class_exists( 'WP_Optimize' ) ) {
330	WP_Optimize()->get_page_cache()->purge();
331	}
332	}
333	}
334