b-blocks / includes / blocks / newsletter / NewsletterHandler.php

NewsletterHandler.php in bBlocks – Essential Gutenberg Blocks & Patterns Collection 2.1.8, at includes/blocks/newsletter/NewsletterHandler.php

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1	<?php
2	/**
3	* Newsletter Optin Block — AJAX submission handler.
4	*
5	* Receives subscribe submissions from the Newsletter Optin block frontend
6	* (src/newsletter-optin/view.js) and emails the subscriber details to the
7	* configured recipient.
8	*
9	* SECURITY: the mail recipient is NEVER taken from the client POST. It is
10	* resolved server-side by parsing the saved block attributes of the post that
11	* contains the newsletter form (per-block `adminEmail` override), falling back
12	* to the site admin email. This mirrors the open-mail-relay fix applied to the
13	* popup-optin handler and prevents an unauthenticated caller from redirecting
14	* notification emails to an arbitrary address.
15	*
16	* @package bBlocks
17	*/
18
19	if ( ! defined( 'ABSPATH' ) ) {
20	exit;
21	}
22
23	if ( ! class_exists( 'BBlocksNewsletterHandler' ) ) {
24
25	class BBlocksNewsletterHandler {
26
27	public function __construct() {
28	add_action( 'wp_ajax_bb_newsletter_optin', [ $this, 'handle_submit' ] );
29	add_action( 'wp_ajax_nopriv_bb_newsletter_optin', [ $this, 'handle_submit' ] );
30	}
31
32	/**
33	* Resolve the mail recipient from saved block content, never from POST.
34	*
35	* Walks the blocks of the given post, finds the first
36	* `b-blocks/newsletter-optin` block with a non-empty, valid `adminEmail`
37	* attribute, and returns it. Falls back to the site admin email.
38	*
39	* @param int $post_id Post that contained the form.
40	* @return string A valid recipient email, or '' if none can be resolved.
41	*/
42	private function resolve_recipient( $post_id ) {
43	$fallback = get_option( 'admin_email' );
44	$fallback = is_email( $fallback ) ? $fallback : '';
45
46	if ( $post_id <= 0 ) {
47	return $fallback;
48	}
49
50	$post = get_post( $post_id );
51	if ( ! $post \|\| empty( $post->post_content ) ) {
52	return $fallback;
53	}
54
55	// Only consider published/viewable posts to avoid leaking config.
56	if ( ! in_array( $post->post_status, [ 'publish', 'private' ], true ) ) {
57	return $fallback;
58	}
59
60	if ( ! has_blocks( $post->post_content ) ) {
61	return $fallback;
62	}
63
64	$blocks = parse_blocks( $post->post_content );
65	$override = $this->find_admin_email( $blocks );
66
67	if ( '' !== $override && is_email( $override ) ) {
68	return $override;
69	}
70
71	return $fallback;
72	}
73
74	/**
75	* Recursively search parsed blocks for a newsletter-optin adminEmail override.
76	*
77	* @param array $blocks Parsed block tree.
78	* @return string The first valid override found, or ''.
79	*/
80	private function find_admin_email( $blocks ) {
81	foreach ( $blocks as $block ) {
82	if ( isset( $block['blockName'] ) && 'b-blocks/newsletter-optin' === $block['blockName'] ) {
83	if ( ! empty( $block['attrs']['adminEmail'] ) ) {
84	$candidate = sanitize_email( (string) $block['attrs']['adminEmail'] );
85	if ( '' !== $candidate && is_email( $candidate ) ) {
86	return $candidate;
87	}
88	}
89	}
90
91	if ( ! empty( $block['innerBlocks'] ) && is_array( $block['innerBlocks'] ) ) {
92	$nested = $this->find_admin_email( $block['innerBlocks'] );
93	if ( '' !== $nested ) {
94	return $nested;
95	}
96	}
97	}
98
99	return '';
100	}
101
102	public function handle_submit() {
103	// Verify nonce.
104	$nonce = isset( $_POST['_wpnonce'] ) ? sanitize_text_field( wp_unslash( $_POST['_wpnonce'] ) ) : '';
105	if ( '' === $nonce \|\| ! wp_verify_nonce( $nonce, 'bb_newsletter_optin' ) ) {
106	wp_send_json_error( [ 'message' => __( 'Security check failed. Please reload the page and try again.', 'b-blocks' ) ] );
107	}
108
109	// Transient-based per-IP rate limit (max 5 submissions per 60 seconds).
110	BBlocksOptinRateLimit::check( 'bb_no' );
111
112	// Validate email.
113	$email_raw = isset( $_POST['bb_no_email'] ) ? sanitize_email( wp_unslash( $_POST['bb_no_email'] ) ) : '';
114	if ( '' === $email_raw \|\| ! is_email( $email_raw ) ) {
115	wp_send_json_error( [ 'message' => __( 'Please enter a valid email address.', 'b-blocks' ) ] );
116	}
117
118	// Optional name.
119	$name = isset( $_POST['bb_no_name'] ) ? sanitize_text_field( wp_unslash( $_POST['bb_no_name'] ) ) : '';
120
121	// Resolve recipient SERVER-SIDE from saved block config — never POST.
122	$post_id = isset( $_POST['post_id'] ) ? absint( wp_unslash( $_POST['post_id'] ) ) : 0;
123	$recipient = $this->resolve_recipient( $post_id );
124
125	if ( '' === $recipient \|\| ! is_email( $recipient ) ) {
126	wp_send_json_error( [ 'message' => __( 'Subscription could not be processed. Please try again later.', 'b-blocks' ) ] );
127	}
128
129	// Strip HTML tags and CRLF from site name to prevent mail-header injection.
130	$site_name = wp_strip_all_tags( wp_specialchars_decode( get_bloginfo( 'name' ), ENT_QUOTES ) );
131	$site_name = str_replace( [ "\r", "\n" ], ' ', $site_name );
132
133	/* translators: %s: site name */
134	$subject = sprintf( __( 'New newsletter subscriber on %s', 'b-blocks' ), $site_name );
135
136	$lines = [];
137	$lines[] = __( 'You have a new newsletter subscriber.', 'b-blocks' );
138	$lines[] = '';
139	if ( '' !== $name ) {
140	/* translators: %s: subscriber name */
141	$lines[] = sprintf( __( 'Name: %s', 'b-blocks' ), $name );
142	}
143	/* translators: %s: subscriber email */
144	$lines[] = sprintf( __( 'Email: %s', 'b-blocks' ), $email_raw );
145
146	$message = implode( "\n", $lines );
147	$headers = [ 'Reply-To: ' . $email_raw ];
148
149	$sent = wp_mail( $recipient, $subject, $message, $headers );
150
151	if ( ! $sent ) {
152	wp_send_json_error( [ 'message' => __( 'Subscription could not be processed. Please try again later.', 'b-blocks' ) ] );
153	}
154
155	wp_send_json_success( [ 'message' => __( 'Thank you for subscribing!', 'b-blocks' ) ] );
156	}
157	}
158
159	new BBlocksNewsletterHandler();
160	}
161