Changed source root directory

html/wp-content/plugins/contact-form-7-mailchimp-extension/includes/signals/Security/Signature.php

@@ -0,0 +1,38 @@
+<?php
+/**
+ * Cryptographic signature handler.
+ *
+ * @package   contact-form-7-mailchimp-extension
+ * @author    renzo.johnson@gmail.com
+ * @copyright 2014-2026 https://renzojohnson.com
+ * @license   GPL-3.0+
+ */
+
+namespace Cmatic\Metrics\Security;
+
+defined( 'ABSPATH' ) || exit;
+
+class Signature {
+
+	const PUBLIC_KEY = 'chimpmatic_lite_v1';
+
+	public static function generate( $install_id, $timestamp, $payload_json ) {
+		$derived_secret = self::derive_secret( $install_id );
+		$string_to_sign = $install_id . $timestamp . $payload_json;
+
+		return hash_hmac( 'sha256', $string_to_sign, $derived_secret );
+	}
+
+	public static function derive_secret( $install_id ) {
+		return hash( 'sha256', $install_id . self::PUBLIC_KEY );
+	}
+
+	public static function validate( $signature, $install_id, $timestamp, $payload_json ) {
+		$expected = self::generate( $install_id, $timestamp, $payload_json );
+		return hash_equals( $expected, $signature );
+	}
+
+	public static function get_public_key() {
+		return self::PUBLIC_KEY;
+	}
+}