Scissors/patches/server/0044-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/net/minecraft/network/chat/Component.java b/src/main/java/net/minecraft/network/chat/Component.java
index a2149452ee461002ea74189c5aa49cddd943d0cf..f1d1501211a923c0ccab6b5982887c3a9262889b 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; // Scissors
 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");
+            }
+        // Scissors end
             if (jsonelement.isJsonPrimitive()) {
                 return Component.literal(jsonelement.getAsString());
             } else {
@@ -273,7 +281,7 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
 
                         while (iterator.hasNext()) {
                             JsonElement jsonelement1 = (JsonElement) iterator.next();
-                            MutableComponent ichatmutablecomponent1 = this.deserialize(jsonelement1, jsonelement1.getClass(), jsondeserializationcontext);
+                            MutableComponent ichatmutablecomponent1 = this.deserialize(jsonelement1, jsondeserializationcontext, depth + 1); // Scissors
 
                             if (ichatmutablecomponent == null) {
                                 ichatmutablecomponent = ichatmutablecomponent1;
@@ -297,12 +305,17 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
                         s = GsonHelper.getAsString(jsonobject, "translate");
                         String s1 = GsonHelper.getAsString(jsonobject, "fallback", (String) null);
 
+                        // Scissors start - 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;
+                        // Scissors end
                         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)); // Scissors
                             }
 
                             ichatmutablecomponent = Component.translatableWithFallback(s, s1, aobject);
@@ -318,7 +331,7 @@ 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); // Scissors
 
                         ichatmutablecomponent = Component.selector(GsonHelper.getAsString(jsonobject, "selector"), optional);
                     } else if (jsonobject.has("keybind")) {
@@ -329,7 +342,7 @@ 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); // Scissors
                         boolean flag = GsonHelper.getAsBoolean(jsonobject, "interpret", false);
                         Object object;
 
@@ -356,7 +369,7 @@ 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)); // Scissors
                         }
                     }
 
@@ -366,6 +379,12 @@ public interface Component extends Message, FormattedText, Iterable<Component> {
             }
         }
 
+        // Scissors start
+        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;
@@ -384,8 +403,10 @@ 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) {