feat: obfuscate all email addresses and mailto links as HTML entities

Added EmailObfuscator class (src/EmailObfuscator.php) that converts
email addresses to HTML decimal entities (e.g. foo@...)
so browsers render them correctly but bots and scrapers see gibberish.

Methods:
- email($addr): obfuscate for display in HTML content
- mailto($addr): return obfuscated mailto: href
- obfuscateHtml($html): post-process rendered HTML to obfuscate all
  mailto: links (used after Parsedown/Markdown rendering)

Applied to:
- partage/index.php: mailto link at top + error scenarios via _flash_contact
  flag rendered in form.php (outside htmlspecialchars to avoid double-escape)
- admin/acces.php: request email mailto links
- admin/file-access.php: request email mailto links
- public/about.php: contact email mailto links
- public/tfe.php: author contact mailto links
- AboutController: Parsedown output post-processing
- LicenceController: Parsedown output post-processing
- Dispatcher::render(): require_once EmailObfuscator for all public views

Also fixed _flash_contact session flag in form.php partial to show
contact email line on share link validation errors (separate from
flash_error/warning to bypass htmlspecialchars double-escaping).

TODO.md

@@ -26,3 +26,4 @@
 - [x] Add xamxam@erg.be mailto link at top of student (partage) form
 - [x] On validation error, append "envoyez un e-mail à xamxam@erg.be" to flash error message
 - [x] Preserve uploaded file names across validation redirects: store in session, display as warning on re-render so the student knows which files to re-select
+- [x] Obfuscate all email addresses and mailto: links as HTML decimal entities site-wide (EmailObfuscator class, applied in templates + Parsedown post-processing)

app/public/admin/acces.php

@@ -2,6 +2,7 @@
 require_once __DIR__ . '/../../bootstrap.php';
 require_once __DIR__ . '/../../src/AdminAuth.php';
 require_once __DIR__ . '/../../src/ShareLink.php';
+require_once APP_ROOT . '/src/EmailObfuscator.php';
 
 App::adminGuard();
 

app/public/partage/index.php

@@ -8,6 +8,7 @@
  *   /partage/recapitulatif.php?id=N - Post-submission confirmation page
  */
 require_once __DIR__ . '/../../bootstrap.php';
+require_once APP_ROOT . '/src/EmailObfuscator.php';
 
 // Parse the requested path from REQUEST_URI
 $requestUri = $_SERVER['REQUEST_URI'] ?? '';
@@ -380,7 +381,7 @@ function renderShareLinkForm(string $slug, array $link): void
 
             <div class="share-help-contact">
                 <p>Des questions ou un problème avec le formulaire ?
-                <a href="mailto:xamxam@erg.be">xamxam@erg.be</a></p>
+                <a href="<?= EmailObfuscator::mailto('xamxam@erg.be') ?>"><?= EmailObfuscator::email('xamxam@erg.be') ?></a></p>
             </div>
 
             <?php
@@ -527,8 +528,8 @@ function handleShareLinkSubmission(string $slug): void
         // Repopulate the form and surface a clear warning to the student.
         // Store as plain text — htmlspecialchars() is applied at render time.
         $_SESSION['_flash_warning'] = 'Votre soumission ressemble à un TFE déjà enregistré.'
-            . "\n" . $e->existingIdentifier . ' — ' . $e->existingTitle . ' (' . $e->existingYear . ')'
-            . "\nSi vous pensez qu'il s'agit d'une erreur, vous pouvez contacter l'équipe à xamxam@erg.be.";
+            . "\n" . $e->existingIdentifier . ' — ' . $e->existingTitle . ' (' . $e->existingYear . ')';
+        $_SESSION['_flash_contact'] = true;
         $_SESSION['form_data_share_' . $slug] = $_POST;
         storePrimedFiles($slug);
         $_SESSION[$shareCsrfKey] = bin2hex(random_bytes(32)); // Regenerate token
@@ -544,8 +545,8 @@ function handleShareLinkSubmission(string $slug): void
         ]);
         ErrorHandler::log('partage_submit', $e, ['slug' => $slug, 'author' => $authorName]);
 
-        $_SESSION['_flash_error'] = ErrorHandler::userMessage($e)
-            . "\n\nSi le problème persiste, envoyez un e-mail à xamxam@erg.be.";
+        $_SESSION['_flash_error'] = ErrorHandler::userMessage($e);
+        $_SESSION['_flash_contact'] = true;
         $_SESSION['form_data_share_' . $slug] = $_POST;
         storePrimedFiles($slug);
         $_SESSION[$shareCsrfKey] = bin2hex(random_bytes(32)); // Regenerate token

app/src/Controllers/AboutController.php

@@ -3,6 +3,7 @@
 require_once APP_ROOT . '/src/Database.php';
 require_once APP_ROOT . '/src/Parsedown.php';
 require_once APP_ROOT . '/src/ErrorHandler.php';
+require_once APP_ROOT . '/src/EmailObfuscator.php';
 
 class AboutController
 {
@@ -35,7 +36,7 @@ class AboutController
 
         return [
             'currentNav'      => 'apropos',
-            'aboutHtml'       => $pd->text($rawContent),
+            'aboutHtml'       => EmailObfuscator::obfuscateHtml($pd->text($rawContent)),
             'contacts'        => $contacts,
             'pageTitle'       => 'À Propos – XAMXAM',
             'metaDescription' => "À propos de XAMXAM, le répertoire des mémoires de fin d'études de l'erg – École de Recherches Graphiques de Bruxelles.",

app/src/Controllers/LicenceController.php

@@ -3,6 +3,7 @@
 require_once APP_ROOT . '/src/Database.php';
 require_once APP_ROOT . '/src/Parsedown.php';
 require_once APP_ROOT . '/src/ErrorHandler.php';
+require_once APP_ROOT . '/src/EmailObfuscator.php';
 
 class LicenceController
 {
@@ -26,7 +27,7 @@ class LicenceController
 
         $pd = new Parsedown();
         $pd->setSafeMode(true);
-        $html = $pd->text($content);
+        $html = EmailObfuscator::obfuscateHtml($pd->text($content));
 
         return [
             'content'          => $content,

app/src/Dispatcher.php

@@ -185,6 +185,8 @@ class Dispatcher
      */
     private function render(string $view, array $vars): void
     {
+        require_once APP_ROOT . '/src/EmailObfuscator.php';
+
         $viewPath = APP_ROOT . '/templates/' . $view . '.php';
         if (!file_exists($viewPath)) {
             http_response_code(500);

app/src/EmailObfuscator.php

@@ -0,0 +1,119 @@
+<?php
+
+/**
+ * EmailObfuscator
+ *
+ * Obfuscates email addresses as HTML decimal entities so they render
+ * correctly in browsers but are invisible to most bots and scrapers.
+ *
+ * Example:
+ *   obfuscateEmail('foo@example.com')
+ *   → &#102;&#111;&#111;&#64;&#101;&#120;&#97;&#109;&#112;&#108;&#101;&#46;&#99;&#111;&#109;
+ *
+ *   obfuscateMailto('foo@example.com')
+ *   → &#109;&#97;&#105;&#108;&#116;&#111;&#58;&#102;&#111;&#111;&#64;&#101;&#120;...
+ *     (usable inside href="...")
+ *
+ *   obfuscateEmailText('Contact xamxam@erg.be for help')
+ *   → 'Contact &#120;&#97;...@&#101;&#114;... for help'
+ *     (replaces email addresses found in plain text)
+ *
+ * Usage:
+ *   require_once APP_ROOT . '/src/EmailObfuscator.php';
+ *   echo '<a href="' . EmailObfuscator::mailto('name@domain.com') . '">' . EmailObfuscator::email('name@domain.com') . '</a>';
+ */
+
+class EmailObfuscator
+{
+    /**
+     * Obfuscate an email address for display in HTML content.
+     */
+    public static function email(string $address): string
+    {
+        return self::encode($address);
+    }
+
+    /**
+     * Obfuscate a mailto: link for use in an href attribute.
+     * Returns 'mailto:' followed by the obfuscated email.
+     */
+    public static function mailto(string $address): string
+    {
+        return 'mailto:' . self::encode($address);
+    }
+
+    /**
+     * Replace plain-text email addresses in a string with obfuscated versions.
+     * Only replaces addresses that appear as bare text (not already inside HTML entities).
+     */
+    public static function emailText(string $text): string
+    {
+        return preg_replace_callback(
+            '/\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}\b/',
+            fn(array $m) => self::encode($m[0]),
+            $text
+        );
+    }
+
+    /**
+     * Obfuscate a mailto: URL found in text (e.g. from Markdown or user input).
+     * Matches 'mailto:user@domain.com' pattern.
+     */
+    public static function mailtoInText(string $text): string
+    {
+        return preg_replace_callback(
+            '/mailto:([A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,})/i',
+            fn(array $m) => 'mailto:' . self::encode($m[1]),
+            $text
+        );
+    }
+
+    /**
+     * Post-process rendered HTML: obfuscate all mailto: links and their
+     * visible text (email addresses) so bots can't scrape them.
+     *
+     * Matches patterns like:
+     *   <a href="mailto:foo@bar.com">foo@bar.com</a>
+     *   <a href="mailto:foo@bar.com">some text</a>
+     *
+     * In the second case, only the href is obfuscated (the link text is kept).
+     */
+    public static function obfuscateHtml(string $html): string
+    {
+        // Match <a> tags whose href starts with mailto:
+        return preg_replace_callback(
+            '/<a\s[^>]*href="mailto:([^"]+)"[^>]*>(.*?)<\/a>/is',
+            function (array $m): string {
+                $email      = $m[1];
+                $linkText   = $m[2];
+                $obfuscated = self::encode($email);
+
+                // If the link text is the email itself, replace it too
+                $text = strip_tags($linkText);
+                if ($text === $email) {
+                    $linkText = self::encode($linkText);
+                }
+
+                // Rebuild the tag with obfuscated values
+                return str_replace(
+                    ['mailto:' . $email, '>' . $m[2] . '<'],
+                    ['mailto:' . $obfuscated, '>' . $linkText . '<'],
+                    $m[0]
+                );
+            },
+            $html
+        );
+    }
+
+    // ── Private ───────────────────────────────────────────────────────────
+
+    private static function encode(string $s): string
+    {
+        $out = '';
+        $len = strlen($s);
+        for ($i = 0; $i < $len; $i++) {
+            $out .= '&#' . ord($s[$i]) . ';';
+        }
+        return $out;
+    }
+}

app/templates/admin/acces.php

@@ -181,6 +181,19 @@
 +%%%%%%% diff from: somsyvxz 249f7943 "Bulk bar anti-shift, tags icons, AP no-wrap, credits reorder" (rebased revision)
 +\\\\\\\        to: kvyyvksn c5873f06 "fix: add help email, preserve file names on validation error, license fix" (rebased revision)
 ++                        $linkName = $link['name'] ?? '';
+++                        $linkExpiresVal = $link['expires_at'] ? date('Y-m-d\TH:i', strtotime($link['expires_at'])) : '';
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% diff from: kvyyvksn c5873f06 "fix: add help email, preserve file names on validation error, license fix" (rebased revision)
+\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\        to: somsyvxz 249f7943 "Bulk bar anti-shift, tags icons, AP no-wrap, credits reorder" (rebased revision)
+-                        $linkName = $link['name'] ?? '';
+-                        $linkExpiresVal = $link['expires_at'] ? date('Y-m-d\TH:i', strtotime($link['expires_at'])) : '';
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% diff from: somsyvxz 14a3cd10 "Bulk bar anti-shift, tags icons, AP no-wrap, credits reorder" (rebase destination)
+\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\        to: roqtyzln d714ae9b "feat: obfuscate all email addresses and mailto links as HTML entities" (rebased revision)
+                         $linkName = $link['name'] ?? '';
+                         $linkExpiresVal = $link['expires_at'] ? date('Y-m-d\TH:i', strtotime($link['expires_at'])) : '';
+                         $linkLockedYear = $link['locked_year'] ?? null;
++%%%%%%% diff from: somsyvxz 249f7943 "Bulk bar anti-shift, tags icons, AP no-wrap, credits reorder" (rebased revision)
++\\\\\\\        to: roqtyzln 34d91340 "feat: obfuscate all email addresses and mailto links as HTML entities" (rebased revision)
+++                        $linkName = $link['name'] ?? '';
 ++                        $linkExpiresVal = $link['expires_at'] ? date('Y-m-d\TH:i', strtotime($link['expires_at'])) : '';
                     ?>
                     <tr class="admin-table-row" onclick="event.stopPropagation(); window.open('/partage/<?= urlencode($link['slug']) ?>', '_blank')" style="cursor:pointer">
@@ -367,9 +380,7 @@
                             <div class="access-req-card__info">
                                 <div>
                                     <strong>Email :</strong>
-                                    <a href="mailto:<?= htmlspecialchars($req['email']) ?>">
-                                        <?= htmlspecialchars($req['email']) ?>
-                                    </a>
+                                    <a href="<?= EmailObfuscator::mailto($req['email']) ?>"><?= htmlspecialchars($req['email']) ?></a>
                                 </div>
                                 <div>
                                     <strong>Date :</strong>

app/templates/admin/file-access.php

@@ -59,9 +59,7 @@
                         <div class="access-req-card__info">
                             <div>
                                 <strong>Email :</strong>
-                                <a href="mailto:<?= htmlspecialchars($req['email']) ?>">
-                                    <?= htmlspecialchars($req['email']) ?>
-                                </a>
+                                <a href="<?= EmailObfuscator::mailto($req['email']) ?>"><?= htmlspecialchars($req['email']) ?></a>
                             </div>
                             <div>
                                 <strong>Date :</strong>

app/templates/partials/form/form.php

@@ -110,10 +110,12 @@ $checkedFormatsForSiteWeb = $checkedFormatsForSiteWeb ?? [];
     $flashError = $_SESSION["_flash_error"] ?? null;
     $flashWarning = $_SESSION["_flash_warning"] ?? null;
     $flashSuccess = $_SESSION["_flash_success"] ?? null;
+    $flashContact = $_SESSION["_flash_contact"] ?? false;
     unset(
         $_SESSION["_flash_error"],
         $_SESSION["_flash_warning"],
         $_SESSION["_flash_success"],
+        $_SESSION["_flash_contact"],
     );
     ?>
     <?php if ($flashError): ?>
@@ -127,6 +129,13 @@ $checkedFormatsForSiteWeb = $checkedFormatsForSiteWeb ?? [];
     ) ?></div>
     <script>document.addEventListener('DOMContentLoaded',function(){var el=document.getElementById('flash-warning');if(el){el.scrollIntoView({behavior:'smooth',block:'center'});el.focus();}});</script>
     <?php endif; ?>
+    <?php if ($flashContact && $mode === 'partage'): ?>
+    <?php require_once APP_ROOT . '/src/EmailObfuscator.php'; ?>
+    <div class="flash-info" role="alert">
+        Si le problème persiste, envoyez un e-mail à
+        <a href="<?= EmailObfuscator::mailto('xamxam@erg.be') ?>"><?= EmailObfuscator::email('xamxam@erg.be') ?></a>.
+    </div>
+    <?php endif; ?>
     <?php if ($flashSuccess): ?>
     <div class="flash-success" role="alert"><?= htmlspecialchars(
         $flashSuccess,

app/templates/public/about.php

@@ -83,9 +83,7 @@ function renderEntries(array $entries): string
                             fn($e) => !empty($e),
                         );
                         foreach ($emails as $email): ?>
-                        <a href="mailto:<?= htmlspecialchars(
-                            $email,
-                        ) ?>"><?= htmlspecialchars($email) ?></a>
+                        <a href="<?= EmailObfuscator::mailto($email) ?>"><?= htmlspecialchars($email) ?></a>
                         <?php endforeach;
                         ?>
                     </address>

app/templates/public/tfe.php

@@ -252,9 +252,7 @@
                                 <span class="sr-only">(ouvre dans un nouvel onglet)</span>
                             </a>
                         <?php elseif ($_isEmail): ?>
-                            <a href="mailto:<?= htmlspecialchars(
-                                $_contact,
-                            ) ?>"><?= htmlspecialchars($_contact) ?></a>
+                            <a href="<?= EmailObfuscator::mailto($_contact) ?>"><?= htmlspecialchars($_contact) ?></a>
                         <?php else: ?>
                             <?= htmlspecialchars($_contact) ?>
                         <?php endif;