From 3d546e4bfe491d84b058a4a50a48573977bc87c4 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 5 Feb 2026 21:46:31 +0000
Subject: [PATCH 1/2] Fix hostname label length validation to enforce RFC 1035
 limits

Co-authored-by: DannyvdSluijs <618940+DannyvdSluijs@users.noreply.github.com>
---
 src/JsonSchema/Constraints/FormatConstraint.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/JsonSchema/Constraints/FormatConstraint.php b/src/JsonSchema/Constraints/FormatConstraint.php
index 9ed4df9d..f888ebef 100644
--- a/src/JsonSchema/Constraints/FormatConstraint.php
+++ b/src/JsonSchema/Constraints/FormatConstraint.php
@@ -210,7 +210,7 @@ protected function validateHostname($host)
             return true;
         }
 
-        $hostnameRegex = '/^(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9])$/i';
+        $hostnameRegex = '/^(?!-)(?!.*?[^A-Za-z0-9\-\.])(?:(?!-)[A-Za-z0-9](?:[A-Za-z0-9\-]{0,61}[A-Za-z0-9])?\.)*(?!-)[A-Za-z0-9](?:[A-Za-z0-9\-]{0,61}[A-Za-z0-9])?$/';
 
         return preg_match($hostnameRegex, $host);
     }

From 0ef4138556144b39b3ec4637e60f1cf5a2075a51 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 5 Feb 2026 22:07:05 +0000
Subject: [PATCH 2/2] Add RFC 1035 comment explaining hostname label length
 limit

Co-authored-by: DannyvdSluijs <618940+DannyvdSluijs@users.noreply.github.com>
---
 src/JsonSchema/Constraints/FormatConstraint.php | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/JsonSchema/Constraints/FormatConstraint.php b/src/JsonSchema/Constraints/FormatConstraint.php
index f888ebef..c38488dd 100644
--- a/src/JsonSchema/Constraints/FormatConstraint.php
+++ b/src/JsonSchema/Constraints/FormatConstraint.php
@@ -210,6 +210,7 @@ protected function validateHostname($host)
             return true;
         }
 
+        // RFC 1035: labels are max 63 chars (1 start + 0-61 middle + 1 end)
         $hostnameRegex = '/^(?!-)(?!.*?[^A-Za-z0-9\-\.])(?:(?!-)[A-Za-z0-9](?:[A-Za-z0-9\-]{0,61}[A-Za-z0-9])?\.)*(?!-)[A-Za-z0-9](?:[A-Za-z0-9\-]{0,61}[A-Za-z0-9])?$/';
 
         return preg_match($hostnameRegex, $host);