Block bot registrations and add cron cleanup for unconfirmed accounts

register.php was a fully open signup form with no bot defenses — the
likely source of the unconfirmed accounts piling up in admin/users.php.

- Add an always-on honeypot field + timing trap to register.php: either
  tripping silently pretends success without creating an account, so a
  bot doesn't learn it was caught. No configuration needed.

- Add optional Google reCAPTCHA v3 support (includes/recaptcha.php,
  recaptcha_enabled()/verify_recaptcha(), no Composer dependency — a
  raw file_get_contents() POST like mailer.php's SMTP socket approach).
  A failed check here shows a real, visible error instead of the silent
  honeypot path, since a legitimate low-score user deserves a retry.

- Configure it through admin/settings.php's new "Bot Protection" section,
  mirroring the existing SMTP pattern exactly: recaptcha_enabled/
  recaptcha_site_key/recaptcha_secret_key in site_settings, secret key
  masked the same way smtp_pass now is (blank submission keeps it
  unchanged). install.php seeds sane defaults so the feature stays off
  until explicitly configured — fully backward compatible.

- Add cron/cleanup_unconfirmed.php: deletes accounts still unconfirmed
  after 3 days. CLI-only (refuses to run over HTTP, and cron/.htaccess
  denies web access to the directory as a second layer) since it's an
  unattended, irreversible deletion. Safe by construction — login.php
  already refuses login to unconfirmed accounts, so these rows can never
  own a session/novena_group/custom_prayer row. Not wired up
  automatically; README documents the Hostinger cron job to schedule it.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

README.md

@@ -64,6 +64,20 @@ chmod 755 uploads/
 
 Configure outbound email in **Admin → Settings** for registration confirmation and password reset emails. If left blank, the app will auto-confirm new users instead.
 
+### 6. Bot protection (optional)
+
+`register.php` always runs a built-in honeypot + timing trap against scripted signups — no setup needed. On top of that, you can enable Google reCAPTCHA v3: register your domain at [google.com/recaptcha](https://www.google.com/recaptcha/admin) (choose **reCAPTCHA v3**), then enter the Site Key and Secret Key in **Admin → Settings → Bot Protection**.
+
+### 7. Scheduled cleanup of unconfirmed accounts (optional)
+
+`cron/cleanup_unconfirmed.php` permanently deletes accounts that are still unconfirmed 3 days after registering — useful for clearing out bot signups that get past the defenses above. It's CLI-only (refuses to run over HTTP) and is not wired up automatically; schedule it yourself as a cron job. In Hostinger's hPanel: **Advanced → Cron Jobs** → run daily:
+
+```bash
+php /home/<your-account>/domains/loveandrosary.com/public_html/cron/cleanup_unconfirmed.php
+```
+
+(Adjust the path to match your actual hosting account.) Confirmed accounts are never touched — only rows with `email_confirmed = 0`.
+
 ## Upgrading an Existing Install
 
 `schema.sql` reflects the current database structure. For a production database that predates the `failed_login_attempts` / `locked_until` login-lockout columns, run this once against it manually — it's not applied automatically since there's no migration runner against a live database:
@@ -101,11 +115,14 @@ Rosary/
 ├── config/
 │   ├── db.example.php  # Copy → db.php and fill in credentials
 │   └── db.php          # (gitignored — contains real credentials)
+├── cron/
+│   └── cleanup_unconfirmed.php  # CLI-only; schedule via host cron
 ├── data/
 │   └── prayers.php     # All prayer text + build_decade_slides()
 ├── includes/
 │   ├── auth.php        # require_auth(), current_user(), has_role(), login lockout
 │   ├── csrf.php        # csrf_token(), csrf_field(), csrf_verify()
+│   ├── recaptcha.php   # recaptcha_enabled(), verify_recaptcha()
 │   ├── build_slides.php
 │   ├── donate.php
 │   └── mailer.php

admin/settings.php

@@ -6,6 +6,7 @@ require_once __DIR__ . '/../config/db.php';
 require_once __DIR__ . '/../includes/auth.php';
 require_once __DIR__ . '/../includes/mailer.php';
 require_once __DIR__ . '/../includes/csrf.php';
+require_once __DIR__ . '/../includes/recaptcha.php';
 
 require_role('superadmin');
 
@@ -20,19 +21,27 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
     $action = $_POST['action'] ?? 'save';
 
     if ($action === 'save') {
-        // smtp_pass is handled separately: the form always renders it blank
+        // smtp_pass and recaptcha_secret_key are handled separately below:
-        // (see below), so a blank submission means "leave it unchanged",
+        // the form always renders them blank, so a blank submission means
-        // not "clear it".
+        // "leave it unchanged", not "clear it".
         $keys = ['site_name','site_url','smtp_host','smtp_port','smtp_user','smtp_from','smtp_from_name',
-             'donate_enabled','donate_type','donate_handle','donate_label'];
+             'donate_enabled','donate_type','donate_handle','donate_label',
+             'recaptcha_enabled','recaptcha_site_key'];
+        // Checkboxes are absent from $_POST entirely when unchecked.
+        $checkbox_keys = ['donate_enabled', 'recaptcha_enabled'];
         foreach ($keys as $k) {
             if (isset($_POST[$k])) {
                 set_setting($k, trim($_POST[$k]));
+            } elseif (in_array($k, $checkbox_keys, true)) {
+                set_setting($k, '0');
             }
         }
         if (!empty($_POST['smtp_pass'])) {
             set_setting('smtp_pass', trim($_POST['smtp_pass']));
         }
+        if (!empty($_POST['recaptcha_secret_key'])) {
+            set_setting('recaptcha_secret_key', trim($_POST['recaptcha_secret_key']));
+        }
         $message = 'Settings saved.';
         $site_name = get_setting('site_name', APP_NAME); // refresh
     }
@@ -68,6 +77,9 @@ $settings = [
     'donate_type'    => get_setting('donate_type', 'custom'),
     'donate_handle'  => get_setting('donate_handle', ''),
     'donate_label'   => get_setting('donate_label', ''),
+    'recaptcha_enabled'      => get_setting('recaptcha_enabled', '0'),
+    'recaptcha_site_key'     => get_setting('recaptcha_site_key', ''),
+    'recaptcha_secret_key_set' => get_setting('recaptcha_secret_key') !== '',
 ];
 ?>
 <!DOCTYPE html>
@@ -226,6 +238,45 @@ $settings = [
                 </div>
             </div>
 
+            <div class="settings-section">
+                <h3>Bot Protection (reCAPTCHA)</h3>
+                <p class="help-text" style="margin-top:0;margin-bottom:20px">
+                    Adds invisible Google reCAPTCHA v3 to the registration form, on top of the built-in
+                    honeypot/timing checks. Register your domain at
+                    <a href="https://www.google.com/recaptcha/admin" target="_blank" rel="noopener">google.com/recaptcha</a>
+                    (choose reCAPTCHA v3) to get a Site Key and Secret Key.
+                </p>
+                <div class="form-group">
+                    <label style="display:flex;align-items:center;gap:10px;cursor:pointer">
+                        <input type="checkbox" name="recaptcha_enabled" value="1"
+                               id="recaptcha_enabled"
+                               <?= $settings['recaptcha_enabled'] === '1' ? 'checked' : '' ?>
+                               style="width:18px;height:18px">
+                        <span>Enable reCAPTCHA on registration</span>
+                    </label>
+                </div>
+                <div class="form-grid">
+                    <div class="form-group">
+                        <label for="recaptcha_site_key">Site Key</label>
+                        <input type="text" id="recaptcha_site_key" name="recaptcha_site_key"
+                               autocomplete="off"
+                               value="<?= htmlspecialchars($settings['recaptcha_site_key']) ?>">
+                    </div>
+                    <div class="form-group">
+                        <label for="recaptcha_secret_key">Secret Key</label>
+                        <div class="pass-wrap">
+                            <input type="password" id="recaptcha_secret_key" name="recaptcha_secret_key"
+                                   autocomplete="new-password"
+                                   placeholder="<?= $settings['recaptcha_secret_key_set'] ? '••••••••  (leave blank to keep current)' : '' ?>">
+                            <button type="button" class="pass-toggle" onclick="toggleRecaptchaSecret()">Show</button>
+                        </div>
+                        <p class="help-text">
+                            <?= $settings['recaptcha_secret_key_set'] ? '&#x2713; A secret key is currently set. Leave blank to keep it.' : 'No secret key set.' ?>
+                        </p>
+                    </div>
+                </div>
+            </div>
+
             <div class="form-actions">
                 <button type="submit" class="btn btn-primary">Save Settings</button>
             </div>
@@ -270,6 +321,18 @@ function togglePass() {
         btn.textContent = 'Show';
     }
 }
+
+function toggleRecaptchaSecret() {
+    var inp = document.getElementById('recaptcha_secret_key');
+    var btn = inp.nextElementSibling;
+    if (inp.type === 'password') {
+        inp.type = 'text';
+        btn.textContent = 'Hide';
+    } else {
+        inp.type = 'password';
+        btn.textContent = 'Show';
+    }
+}
 </script>
 </body>
 </html>

cron/.htaccess

@@ -0,0 +1,5 @@
+# Defense in depth: cron/cleanup_unconfirmed.php already refuses to run
+# outside the CLI, but block web access to this directory entirely too.
+Require all denied
+Order allow,deny
+Deny from all

cron/cleanup_unconfirmed.php

@@ -0,0 +1,41 @@
+<?php
+/**
+ * cron/cleanup_unconfirmed.php
+ * Deletes accounts that have sat unconfirmed for more than $days days.
+ *
+ * CLI-only — refuses to run if reached over HTTP, since this performs a
+ * real, irreversible deletion and has no business being web-accessible.
+ *
+ * Schedule this via your host's cron job feature, e.g. once daily:
+ *   php /path/to/Rosary/cron/cleanup_unconfirmed.php
+ *
+ * Safe by construction: login.php refuses login to any account with
+ * email_confirmed = 0, so an unconfirmed account can never have created a
+ * session/novena_group/custom_prayer row — nothing here can orphan data.
+ */
+if (PHP_SAPI !== 'cli') {
+    http_response_code(403);
+    exit('This script may only be run from the command line.');
+}
+
+require_once __DIR__ . '/../config/db.php';
+
+$days = 3;
+$pdo  = get_pdo();
+
+$st = $pdo->prepare("
+    SELECT id, username, email, created_at
+    FROM   users
+    WHERE  email_confirmed = 0
+      AND  created_at < (NOW() - INTERVAL ? DAY)
+");
+$st->execute([$days]);
+$stale = $st->fetchAll();
+
+$del = $pdo->prepare('DELETE FROM users WHERE id = ?');
+foreach ($stale as $u) {
+    $del->execute([$u['id']]);
+    echo date('c') . " deleted unconfirmed user #{$u['id']} ({$u['username']}, {$u['email']}, registered {$u['created_at']})\n";
+}
+
+echo date('c') . ' — ' . count($stale) . " account(s) removed.\n";

includes/recaptcha.php

@@ -0,0 +1,48 @@
+<?php
+/**
+ * includes/recaptcha.php — Google reCAPTCHA v3 verification.
+ * No Composer dependency: uses file_get_contents() with a POST stream context,
+ * matching the no-dependency style of includes/mailer.php.
+ */
+
+/** True if reCAPTCHA is turned on and a site key is configured. */
+function recaptcha_enabled(): bool {
+    return get_setting('recaptcha_enabled', '0') === '1' && get_setting('recaptcha_site_key') !== '';
+}
+
+/**
+ * Verify a reCAPTCHA v3 token against Google's siteverify endpoint.
+ * Returns true only if the request succeeded and the score meets $min_score.
+ */
+function verify_recaptcha(string $token, float $min_score = 0.5): bool {
+    $secret = get_setting('recaptcha_secret_key');
+    if ($secret === '' || $token === '') return false;
+
+    $post_data = http_build_query([
+        'secret'   => $secret,
+        'response' => $token,
+        'remoteip' => $_SERVER['REMOTE_ADDR'] ?? '',
+    ]);
+
+    $context = stream_context_create([
+        'http' => [
+            'method'  => 'POST',
+            'header'  => "Content-Type: application/x-www-form-urlencoded\r\n",
+            'content' => $post_data,
+            'timeout' => 10,
+        ],
+    ]);
+
+    try {
+        $response = @file_get_contents('https://www.google.com/recaptcha/api/siteverify', false, $context);
+        if ($response === false) return false;
+
+        $result = json_decode($response, true);
+        if (!is_array($result)) return false;
+
+        return !empty($result['success']) && (float)($result['score'] ?? 0) >= $min_score;
+    } catch (Throwable $e) {
+        error_log('reCAPTCHA verify error: ' . $e->getMessage());
+        return false;
+    }
+}

install.php

@@ -133,6 +133,9 @@ $defaults = [
     'smtp_from_name' => 'Rosary Presenter',
     'site_name'      => 'Rosary Presenter',
     'site_url'       => '',
+    'recaptcha_enabled'    => '0',
+    'recaptcha_site_key'   => '',
+    'recaptcha_secret_key' => '',
 ];
 $ins_setting = $pdo->prepare('INSERT IGNORE INTO site_settings (key_name, val) VALUES (?, ?)');
 foreach ($defaults as $k => $v) {

register.php

@@ -3,6 +3,7 @@ require_once __DIR__ . '/config/db.php';
 require_once __DIR__ . '/includes/auth.php';
 require_once __DIR__ . '/includes/mailer.php';
 require_once __DIR__ . '/includes/csrf.php';
+require_once __DIR__ . '/includes/recaptcha.php';
 
 _auth_start();
 
@@ -18,6 +19,16 @@ $fields   = ['username' => '', 'display_name' => '', 'email' => ''];
 
 if ($_SERVER['REQUEST_METHOD'] === 'POST') {
     csrf_verify();
+
+    // Honeypot + timing trap: a decoy field real users never see/fill, and a
+    // minimum time between the form being shown and submitted. Either one
+    // tripping means this almost certainly isn't a human — pretend success
+    // without creating an account, so a bot doesn't learn it was caught and
+    // adapt its script.
+    $honeypot     = trim($_POST['website'] ?? '');
+    $shown_at     = (int)($_SESSION['reg_form_shown_at'] ?? 0);
+    $bot_detected = ($honeypot !== '') || (time() - $shown_at < 3);
+
     $username        = trim($_POST['username']        ?? '');
     $display_name    = trim($_POST['display_name']    ?? '');
     $email           = trim($_POST['email']           ?? '');
@@ -26,6 +37,17 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
 
     $fields = compact('username', 'display_name', 'email');
 
+    if ($bot_detected) {
+        $success        = true;
+        $auto_confirmed = false;
+    } else {
+        // reCAPTCHA v3: unlike the honeypot/timing trap above, a failure here
+        // gets a real, visible error — a legitimate low-score user deserves
+        // an explicit retry rather than a silently-discarded submission.
+        if (recaptcha_enabled() && !verify_recaptcha($_POST['recaptcha_token'] ?? '')) {
+            $errors[] = 'We could not verify your submission. Please try again.';
+        }
+
         // Validate username
         if (!preg_match('/^[a-zA-Z0-9_]{3,30}$/', $username)) {
             $errors[] = 'Username must be 3-30 characters and contain only letters, numbers, and underscores.';
@@ -49,9 +71,6 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
             $chk = $pdo->prepare('SELECT id FROM users WHERE username = ? OR email = ?');
             $chk->execute([$username, $email]);
             $existing = $chk->fetchAll();
-        foreach ($existing as $row) {
-            // Re-check which field conflicts
-        }
             if (!empty($existing)) {
                 $chk_u = $pdo->prepare('SELECT id FROM users WHERE username = ?');
                 $chk_u->execute([$username]);
@@ -98,6 +117,12 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
             $auto_confirmed = $auto_confirm;
         }
     }
+}
+
+// Refresh the timing-trap timestamp whenever the form is about to be (re)shown.
+if (!$success) {
+    $_SESSION['reg_form_shown_at'] = time();
+}
 ?>
 <!DOCTYPE html>
 <html lang="en">
@@ -107,6 +132,9 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
     <link rel="icon" type="image/svg+xml" href="<?= BASE_URL ?>/favicon.svg">
     <title>Register — <?= htmlspecialchars(get_setting('site_name', APP_NAME)) ?></title>
     <link rel="stylesheet" href="<?= BASE_URL ?>/assets/css/setup.css">
+    <?php if (recaptcha_enabled()): ?>
+    <script src="https://www.google.com/recaptcha/api.js?render=<?= urlencode(get_setting('recaptcha_site_key')) ?>"></script>
+    <?php endif; ?>
 </head>
 <body class="login-page">
     <div class="login-box" style="max-width:460px">
@@ -133,8 +161,15 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
             </div>
         <?php endif; ?>
 
-        <form method="post" action="<?= BASE_URL ?>/register">
+        <form method="post" action="<?= BASE_URL ?>/register" id="register-form">
             <?= csrf_field() ?>
+            <?php if (recaptcha_enabled()): ?>
+            <input type="hidden" name="recaptcha_token" id="recaptcha_token">
+            <?php endif; ?>
+            <div style="position:absolute;left:-9999px;top:-9999px" aria-hidden="true">
+                <label for="website">Website</label>
+                <input type="text" id="website" name="website" tabindex="-1" autocomplete="off">
+            </div>
             <div class="form-group">
                 <label for="username">Username <span class="required">*</span></label>
                 <input type="text" id="username" name="username"
@@ -176,5 +211,21 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
 
         <?php endif; ?>
     </div>
+
+    <?php if (recaptcha_enabled()): ?>
+    <script>
+        document.getElementById('register-form').addEventListener('submit', function (e) {
+            e.preventDefault();
+            var form = this;
+            grecaptcha.ready(function () {
+                grecaptcha.execute('<?= htmlspecialchars(get_setting('recaptcha_site_key')) ?>', { action: 'register' })
+                    .then(function (token) {
+                        document.getElementById('recaptcha_token').value = token;
+                        form.submit();
+                    });
+            });
+        });
+    </script>
+    <?php endif; ?>
 </body>
 </html>