From e1d4b6adc7d00bb6d907d682ceeb03969866ee9d Mon Sep 17 00:00:00 2001
From: Outfluencer <48880402+Outfluencer@users.noreply.github.com>
Date: Sat, 24 Aug 2024 12:27:05 +0200
Subject: [PATCH] #3731: Update cookie handling with vanilla limits and don't
 allow unrequested cookies

---
 .../java/net/md_5/bungee/protocol/packet/CookieResponse.java  | 2 +-
 .../main/java/net/md_5/bungee/connection/InitialHandler.java  | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/protocol/src/main/java/net/md_5/bungee/protocol/packet/CookieResponse.java b/protocol/src/main/java/net/md_5/bungee/protocol/packet/CookieResponse.java
index 77a541b6..24b1fa05 100644
--- a/protocol/src/main/java/net/md_5/bungee/protocol/packet/CookieResponse.java
+++ b/protocol/src/main/java/net/md_5/bungee/protocol/packet/CookieResponse.java
@@ -23,7 +23,7 @@ public class CookieResponse extends DefinedPacket
     public void read(ByteBuf buf, ProtocolConstants.Direction direction, int protocolVersion)
     {
         cookie = readString( buf );
-        data = readNullable( DefinedPacket::readArray, buf );
+        data = readNullable( read -> DefinedPacket.readArray( read, 5120 ), buf );
     }
 
     @Override
diff --git a/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java b/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java
index 413c8123..3bbf688b 100644
--- a/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java
+++ b/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java
@@ -716,6 +716,10 @@ public class InitialHandler extends PacketHandler implements PendingConnection
 
             throw CancelSendSignal.INSTANCE;
         }
+
+        // if there is no userCon we can't have a connection to a backend server that could have requested this cookie
+        // which means that this cookie is invalid as the proxy also has not requested it
+        Preconditions.checkState( userCon != null, "not requested cookie received" );
     }
 
     @Override