From 74de9799f42fd74dbc53dbac61e930fe07a02179 Mon Sep 17 00:00:00 2001
From: "epieffe.eth" <ferrariepifanio@gmail.com>
Date: Sun, 29 Dec 2024 20:40:25 +0100
Subject: [PATCH] Replace regex with custom logic for MQTT topic matching

---
 .../internal/config/MqttConditionMatcher.java | 34 ++++++++++++++-----
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/runtime/binding-mqtt/src/main/java/io/aklivity/zilla/runtime/binding/mqtt/internal/config/MqttConditionMatcher.java b/runtime/binding-mqtt/src/main/java/io/aklivity/zilla/runtime/binding/mqtt/internal/config/MqttConditionMatcher.java
index 4c0f368a82..92d3f6d83f 100644
--- a/runtime/binding-mqtt/src/main/java/io/aklivity/zilla/runtime/binding/mqtt/internal/config/MqttConditionMatcher.java
+++ b/runtime/binding-mqtt/src/main/java/io/aklivity/zilla/runtime/binding/mqtt/internal/config/MqttConditionMatcher.java
@@ -113,15 +113,31 @@ private boolean topicMatches(String topic, String pattern, long authorization)
                 pattern = pattern.replace(String.format("{guarded[%s].identity}", g.name), identity);
             }
         }
-        return topic.matches(pattern
-                .replace("{", "\\{")
-                .replace("}", "\\}")
-                .replace("[", "\\[")
-                .replace("]", "\\]")
-                .replace(".", "\\.")
-                .replace("$", "\\$")
-                .replace("+", "[^/]*")
-                .replace("#", ".*"));
+        int topicIndex = 0;
+        for (int i = 0; i < pattern.length(); ++i)
+        {
+            char patternChar = pattern.charAt(i);
+            if (patternChar == '#')
+            {
+                return true;
+            }
+            else if (patternChar == '+')
+            {
+                while (topicIndex < topic.length())
+                {
+                    if (topic.charAt(topicIndex) == '/')
+                    {
+                        break;
+                    }
+                    topicIndex++;
+                }
+            }
+            else if (topicIndex == topic.length() || topic.charAt(topicIndex++) != patternChar)
+            {
+                return false;
+            }
+        }
+        return topicIndex == topic.length();
     }
 
     private static List<Matcher> asWildcardMatcher(