[PATCH v2] Implement spamming mitigations for comments

[Jelle van der Waa]

From: Jelle van der Waa <jelle at vdwaa.nl>

Add a hidden input text field named 'website' which is hidden by CSS to
not show up for normal users. Automated bots try to fill in all text
fields, especially 'required' fields such as a 'website' when spamming a
webform. When a comment is posted with the 'website' field filled in
ignore it, so it seems that the submission is succesful.

Signed-off-by: Jelle van der Waa <jelle at vdwaa.nl>
---
 web/html/css/aurweb.css           | 4 ++++
 web/html/pkgbase.php              | 3 ++-
 web/template/pkg_comment_form.php | 1 +
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/web/html/css/aurweb.css b/web/html/css/aurweb.css
index 81bf9ab..aa0a7b0 100644
--- a/web/html/css/aurweb.css
+++ b/web/html/css/aurweb.css
@@ -199,3 +199,7 @@ label.confirmation,
 .error {
 	color: red;
 }
+
+#id_website {
+	display: none;
+}
diff --git a/web/html/pkgbase.php b/web/html/pkgbase.php
index b716644..0241ae3 100644
--- a/web/html/pkgbase.php
+++ b/web/html/pkgbase.php
@@ -117,7 +117,8 @@ if (check_token()) {
 		list($ret, $output) = pkgreq_close($_POST['reqid'], $_POST['reason'], $_POST['comments']);
 	} elseif (current_action("do_EditComaintainers")) {
 		list($ret, $output) = pkgbase_set_comaintainers($base_id, explode("\n", $_POST['users']));
-	} elseif (current_action("do_AddComment")) {
+	} elseif (current_action("do_AddComment") && $_REQUEST['website'] === "") {
+		// website is a hidden field used to detect if a bot filled in all form elements
 		$uid = uid_from_sid($_COOKIE["AURSID"]);
 		list($ret, $output) = pkgbase_add_comment($base_id, $uid, $_REQUEST['comment']);
 		if ($ret && isset($_REQUEST['enable_notifications'])) {
diff --git a/web/template/pkg_comment_form.php b/web/template/pkg_comment_form.php
index 3feee8f..23322a7 100644
--- a/web/template/pkg_comment_form.php
+++ b/web/template/pkg_comment_form.php
@@ -11,6 +11,7 @@
 			<p>
 				<textarea id="id_comment" name="comment" cols="80" rows="10"><?= (isset($comment_id)) ? htmlspecialchars($comment) : "" ?></textarea>
 			</p>
+				<input id="id_website" type="text" name="website"/>
 			<p>
 				<input type="submit" value="<?= (isset($comment_id)) ? __("Save") : __("Add Comment") ?>" />
 				<?php if (!isset($comment_id) && !pkgbase_user_notify($uid, $base_id)): ?>
-- 
2.22.0