From 7b6fa15893532182368ce926ddf2becf80aebf59 Mon Sep 17 00:00:00 2001
From: TheBrokenRail <connor24nolan@live.com>
Date: Sun, 21 Feb 2021 22:16:05 -0500
Subject: [PATCH] Sanitize Chat

---
 mods/src/chat/chat.cpp | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/mods/src/chat/chat.cpp b/mods/src/chat/chat.cpp
index b0ee998..adefb97 100644
--- a/mods/src/chat/chat.cpp
+++ b/mods/src/chat/chat.cpp
@@ -1,4 +1,5 @@
 #include <string>
+#include <cstring>
 #include <cstdio>
 #include <vector>
 #include <pthread.h>
@@ -10,6 +11,11 @@
 
 #include "chat.h"
 
+// Message Limitations
+#define MAX_MESSAGE_LENGTH 512
+#define MINIMUM_MESSAGE_CHARACTER 32
+#define MAXIMUM_MESSAGE_CHARACTER 126
+
 // Send API Command
 static void send_api_command(unsigned char *minecraft, char *str) {
     struct ConnectedClient client;
@@ -30,11 +36,29 @@ static void send_api_chat_command(unsigned char *minecraft, char *str) {
     free(command);
 }
 
+// Sanitize Message
+static void sanitize_message(char **message) {
+    // Store Message Length
+    int length = strlen(*message);
+    // Truncate Message
+    if (length > MAX_MESSAGE_LENGTH) {
+        (*message)[MAX_MESSAGE_LENGTH] = '\0';
+        length = MAX_MESSAGE_LENGTH;
+    }
+    // Loop Through Message
+    for (int i = 0; i < length; i++) {
+        if ((*message)[i] < MINIMUM_MESSAGE_CHARACTER || (*message)[i] > MAXIMUM_MESSAGE_CHARACTER) {
+            // Replace Illegal Character
+            (*message)[i] = '?';
+        }
+    }
+}
 // Send Message To Players
 static void send_message(unsigned char *server_side_network_handler, char *username, char *message) {
     char *full_message = NULL;
     asprintf(&full_message, "<%s> %s", username, message);
     ALLOC_CHECK(full_message);
+    sanitize_message(&full_message);
     (*ServerSideNetworkHandler_displayGameMessage)(server_side_network_handler, std::string(full_message));
     free(full_message);
 }