Scissors/patches/server/0047-Add-depth-limit-to-Component-deserializer.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Luna <lunahatesgogle@gmail.com>
Date: Wed, 31 May 2023 18:14:00 -0300
Subject: [PATCH] Add depth limit to Component deserializer


diff --git a/src/main/java/me/totalfreedom/scissors/ScissorsConfig.java b/src/main/java/me/totalfreedom/scissors/ScissorsConfig.java
index 39b56ca496ed7369ead21805d476c2b813fcdd1d..9659cff6412584190ff0c32e01f602de4ff7d3b3 100644
--- a/src/main/java/me/totalfreedom/scissors/ScissorsConfig.java
+++ b/src/main/java/me/totalfreedom/scissors/ScissorsConfig.java
@@ -87,8 +87,8 @@ public class ScissorsConfig
         config.options().header(HEADER);
         config.options().copyDefaults(true);
 
-        version = getInt("config-version", 4);
-        set("config-version", 4);
+        version = getInt("config-version", 5);
+        set("config-version", 5);
         readConfig(ScissorsConfig.class, null);
     }
 
@@ -175,6 +175,12 @@ public class ScissorsConfig
         excludePlayersFromNbtComponents = getBoolean("excludePlayersFromNbtComponents", false);
     }
 
+    public static int componentDepthLimit = 128;
+    private static void componentDepthLimit()
+    {
+        componentDepthLimit = getInt("componentDepthLimit", 128);
+    }
+
     private static void set(String path, Object val)
     {
         config.set(path, val);
diff --git a/src/main/java/net/minecraft/network/chat/Component.java b/src/main/java/net/minecraft/network/chat/Component.java
index 9c2c22ee548ad77f0912698f33de5f467f32fb7f..ba2879b25e59290ab81501458414a417c121ed03 100644
--- a/src/main/java/net/minecraft/network/chat/Component.java
+++ b/src/main/java/net/minecraft/network/chat/Component.java
@@ -26,6 +26,7 @@ import java.util.List;
 import java.util.Map.Entry;
 import java.util.Optional;
 import javax.annotation.Nullable;
+import me.totalfreedom.scissors.ScissorsConfig; // Scissors
 import net.minecraft.ChatFormatting;
 import net.minecraft.Util;
 import net.minecraft.network.chat.contents.BlockDataSource;
@@ -44,6 +45,7 @@ import net.minecraft.util.GsonHelper;
 import net.minecraft.util.LowerCaseEnumTypeAdapterFactory;
 // CraftBukkit start
 import com.google.common.collect.Streams;
+import java.util.regex.Pattern; // Scissors
 import java.util.stream.Stream;
 // CraftBukkit end
 
@@ -254,10 +256,16 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
                 throw new IllegalStateException("Couldn't get field 'lineStart' for JsonReader", nosuchfieldexception);
             }
         });
+        private static final Pattern PLACEHOLDER_PATTERN = Pattern.compile("%[0-9]+\\$s"); // Scissors
 
         public Serializer() {}
 
-        public MutableComponent deserialize(JsonElement jsonelement, Type type, JsonDeserializationContext jsondeserializationcontext) throws JsonParseException {
+        // Scissors start
+        private MutableComponent deserialize(JsonElement jsonelement, JsonDeserializationContext jsondeserializationcontext, int depth) throws JsonParseException {
+            if (depth > ScissorsConfig.componentDepthLimit) {
+                throw new JsonParseException("Depth limit exceeded");
+            }
+
             if (jsonelement.isJsonPrimitive()) {
                 return Component.literal(jsonelement.getAsString());
             } else {
@@ -266,18 +274,16 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
                 if (!jsonelement.isJsonObject()) {
                     if (jsonelement.isJsonArray()) {
                         JsonArray jsonarray = jsonelement.getAsJsonArray();
-                        // Scissors start
                         if (jsonarray.size() <= 0) {
                             throw new JsonParseException("Unexpected empty array of components");
                         }
-                        // Scissors end
 
                         ichatmutablecomponent = null;
                         Iterator iterator = jsonarray.iterator();
 
                         while (iterator.hasNext()) {
                             JsonElement jsonelement1 = (JsonElement) iterator.next();
-                            MutableComponent ichatmutablecomponent1 = this.deserialize(jsonelement1, jsonelement1.getClass(), jsondeserializationcontext);
+                            MutableComponent ichatmutablecomponent1 = this.deserialize(jsonelement1, jsondeserializationcontext, depth + 1);
 
                             if (ichatmutablecomponent == null) {
                                 ichatmutablecomponent = ichatmutablecomponent1;
@@ -301,12 +307,17 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
                         s = GsonHelper.getAsString(jsonobject, "translate");
                         String s1 = GsonHelper.getAsString(jsonobject, "fallback", (String) null);
 
+                        // Penalize depth for placeholders in translate & fallback
+                        long translate_placeholders = PLACEHOLDER_PATTERN.matcher(s).results().count();
+                        long fallback_placeholders = s1 != null ? PLACEHOLDER_PATTERN.matcher(s1).results().count() : 0;
+                        int penalty = (int)Math.max(translate_placeholders, fallback_placeholders) * 12;
+
                         if (jsonobject.has("with")) {
                             JsonArray jsonarray1 = GsonHelper.getAsJsonArray(jsonobject, "with");
                             Object[] aobject = new Object[jsonarray1.size()];
 
                             for (int i = 0; i < aobject.length; ++i) {
-                                aobject[i] = Serializer.unwrapTextArgument(this.deserialize(jsonarray1.get(i), type, jsondeserializationcontext));
+                                aobject[i] = Serializer.unwrapTextArgument(this.deserialize(jsonarray1.get(i), jsondeserializationcontext, depth + 1 + penalty));
                             }
 
                             ichatmutablecomponent = Component.translatableWithFallback(s, s1, aobject);
@@ -322,7 +333,7 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
 
                         ichatmutablecomponent = Component.score(GsonHelper.getAsString(jsonobject1, "name"), GsonHelper.getAsString(jsonobject1, "objective"));
                     } else if (jsonobject.has("selector")) {
-                        Optional<Component> optional = this.parseSeparator(type, jsondeserializationcontext, jsonobject);
+                        Optional<Component> optional = this.parseSeparator(jsondeserializationcontext, jsonobject, depth + 1);
 
                         ichatmutablecomponent = Component.selector(GsonHelper.getAsString(jsonobject, "selector"), optional);
                     } else if (jsonobject.has("keybind")) {
@@ -333,7 +344,7 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
                         }
 
                         s = GsonHelper.getAsString(jsonobject, "nbt");
-                        Optional<Component> optional1 = this.parseSeparator(type, jsondeserializationcontext, jsonobject);
+                        Optional<Component> optional1 = this.parseSeparator(jsondeserializationcontext, jsonobject, depth + 1);
                         boolean flag = GsonHelper.getAsBoolean(jsonobject, "interpret", false);
                         Object object;
 
@@ -360,7 +371,7 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
                         }
 
                         for (int j = 0; j < jsonarray2.size(); ++j) {
-                            ichatmutablecomponent.append((Component) this.deserialize(jsonarray2.get(j), type, jsondeserializationcontext));
+                            ichatmutablecomponent.append((Component) this.deserialize(jsonarray2.get(j), jsondeserializationcontext, depth + 1));
                         }
                     }
 
@@ -370,6 +381,11 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
             }
         }
 
+        public MutableComponent deserialize(JsonElement jsonelement, Type type, JsonDeserializationContext jsondeserializationcontext) throws JsonParseException {
+            return this.deserialize(jsonelement, jsondeserializationcontext, 1);
+        }
+        // Scissors end
+
         private static Object unwrapTextArgument(Object text) {
             if (text instanceof Component) {
                 Component ichatbasecomponent = (Component) text;
@@ -388,8 +404,10 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
             return text;
         }
 
-        private Optional<Component> parseSeparator(Type type, JsonDeserializationContext context, JsonObject json) {
-            return json.has("separator") ? Optional.of(this.deserialize(json.get("separator"), type, context)) : Optional.empty();
+        // Scissors start
+        private Optional<Component> parseSeparator(JsonDeserializationContext context, JsonObject json, int depth) {
+            return json.has("separator") ? Optional.of(this.deserialize(json.get("separator"), context, depth + 1)) : Optional.empty();
+            // Scissors end
         }
 
         private void serializeStyle(Style style, JsonObject json, JsonSerializationContext context) {