From 7b9d472e06172cc7b40936cbae0f05289b10ef15 Mon Sep 17 00:00:00 2001
From: Case Duckworth
Date: Fri, 20 Jan 2023 15:36:44 -0600
Subject: Some hardening

---
 superstack.php | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/superstack.php b/superstack.php
index c02ae6d..306b7b3 100644
--- a/superstack.php
+++ b/superstack.php
@@ -1,5 +1,18 @@
 <?php
-$site = urldecode($_GET['page']);
+$site = $_GET['page'];
+
+if (empty($site)) {
+	echo "Superstack!\n";
+	return;
+}
+
+if (! preg_match('/substack\.com/', $site)) {
+	echo "Requires a substack URL!";
+	return;
+}
+
+$site = urldecode($site);
+
 $ch = curl_init($site);
 curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
 $page = curl_exec($ch);
@@ -47,3 +60,4 @@ foreach ($content as $el) {
 
     </body>
         </html>
+
-- 
cgit 1.4.1-21-gabe81