From b9dedd77dcb03a0e47ae0beeb12a7f19568beaad Mon Sep 17 00:00:00 2001
From: AxeelAnder <1491773534@qq.com>
Date: Sat, 20 Oct 2018 17:44:34 +0800
Subject: [PATCH] add some anti-cheat code

---
 TShockAPI/Bouncer.cs         | 60 +++++++++++++++++++++++++++++++++++-
 TShockAPI/GetDataHandlers.cs |  2 +-
 TShockAPI/TShock.cs          | 32 +++++++++++++++++++
 3 files changed, 92 insertions(+), 2 deletions(-)

diff --git a/TShockAPI/Bouncer.cs b/TShockAPI/Bouncer.cs
index b71c7de8..79dce7d1 100644
--- a/TShockAPI/Bouncer.cs
+++ b/TShockAPI/Bouncer.cs
@@ -480,10 +480,68 @@ namespace TShockAPI
 
 			if (args.Player.IsBeingDisabled())
 			{
-				args.Player.SendData(PacketTypes.NpcAddBuff, "", id);
 				args.Handled = true;
 				return;
 			}
+
+			if (!args.Player.HasPermission(Permissions.ignorenpcaddbuffdetection))
+			{
+				bool cheat = false;
+
+				if(TShock.NPCAddBuffTimeMax.ContainsKey(type))
+				{
+					if(time > TShock.NPCAddBuffTimeMax[type])
+					{
+						cheat = true;
+					}
+
+					if(npc.townNPC && npc.netID != NPCID.Guide && npc.netID != NPCID.Clothier)
+					{
+						if(type != BuffID.Lovestruck && type != BuffID.Stinky && type != BuffID.DryadsWard &&
+							type != BuffID.Wet && type != BuffID.Slimed)
+						{
+							cheat = true;
+						}
+					}
+					// Want to check voodoo doll but it may be wrong.
+					//else if(npc.netID == NPCID.Guide)
+					//{
+					//	bool hasDoll = false;
+					//	foreach (var item in args.Player.Accessories)
+					//	{
+					//		if (item.netID == ItemID.GuideVoodooDoll)
+					//		{
+					//			hasDoll = true;
+					//			break;
+					//		}
+					//	}
+					//	cheat = !hasDoll;
+					//}
+					//else if (npc.netID == NPCID.Clothier)
+					//{
+					//	bool hasDoll = false;
+					//	foreach (var item in args.Player.Accessories)
+					//	{
+					//		if (item.netID == ItemID.ClothierVoodooDoll)
+					//		{
+					//			hasDoll = true;
+					//			break;
+					//		}
+					//	}
+					//	cheat = !hasDoll;
+					//}
+				}
+				else
+				{
+					cheat = true;
+				}
+
+				if (cheat)
+				{
+					args.Player.Disable("Add buff to NPC abnormally.", DisableFlags.WriteToLogAndConsole);
+					args.Handled = true;
+				}
+			}
 		}
 
 		/// <summary>Handles Buff events.</summary>
diff --git a/TShockAPI/GetDataHandlers.cs b/TShockAPI/GetDataHandlers.cs
index 6673dd64..a7792569 100644
--- a/TShockAPI/GetDataHandlers.cs
+++ b/TShockAPI/GetDataHandlers.cs
@@ -2678,7 +2678,7 @@ namespace TShockAPI
 			if (OnNPCAddBuff(args.Player, args.Data, id, type, time))
 				return true;
 			
-			return true;
+			return false;
 		}
 
 		private static bool HandlePlayerAddBuff(GetDataHandlerArgs args)
diff --git a/TShockAPI/TShock.cs b/TShockAPI/TShock.cs
index f839019d..18cff28e 100644
--- a/TShockAPI/TShock.cs
+++ b/TShockAPI/TShock.cs
@@ -131,6 +131,9 @@ namespace TShockAPI
 		/// </summary>
 		public static Dictionary<string, SecureRest.TokenData> RESTStartupTokens = new Dictionary<string, SecureRest.TokenData>();
 
+		/// <summary>The longest time of buffs players can add to NPCs.</summary>
+		public static Dictionary<byte, short> NPCAddBuffTimeMax;
+
 		/// <summary>The TShock anti-cheat/anti-exploit system.</summary>
 		internal Bouncer Bouncer;
 
@@ -323,6 +326,7 @@ namespace TShockAPI
 				RestApi = new SecureRest(Netplay.ServerIP, Config.RestApiPort);
 				RestManager = new RestManager(RestApi);
 				RestManager.RegisterRestfulCommands();
+				NPCAddBuffTimeMax = InitNPCAddBuffTimeMax();
 				Bouncer = new Bouncer();
 				RegionSystem = new RegionHandler(Regions);
 
@@ -385,6 +389,34 @@ namespace TShockAPI
 			}
 		}
 
+		private Dictionary<byte, short> InitNPCAddBuffTimeMax()
+		{
+			var dict = new Dictionary<byte, short>();
+
+			dict.Add(BuffID.Poisoned, 3600);
+			dict.Add(BuffID.OnFire, 1200);
+			dict.Add(BuffID.CursedInferno, 420);
+			dict.Add(BuffID.Frostburn, 900);
+			dict.Add(BuffID.Ichor, 1200);
+			dict.Add(BuffID.Venom, 1260);
+			dict.Add(BuffID.Midas, 120);
+			dict.Add(BuffID.Wet, 1500);
+			dict.Add(BuffID.Slimed, 1500);
+			dict.Add(BuffID.Lovestruck, 1800);
+			dict.Add(BuffID.Stinky, 1800);
+			dict.Add(BuffID.SoulDrain, 30);
+			dict.Add(BuffID.ShadowFlame, 660);
+			dict.Add(BuffID.DryadsWard, 120);
+			dict.Add(BuffID.BoneJavelin, 900);
+			dict.Add(BuffID.StardustMinionBleed, 900);
+			dict.Add(BuffID.DryadsWardDebuff, 120);
+			dict.Add(BuffID.Daybreak, 300);
+			dict.Add(BuffID.BetsysCurse, 600);
+			dict.Add(BuffID.Oiled, 540);
+
+			return dict;
+		}
+
 		protected void CrashReporter_HeapshotRequesting(object sender, EventArgs e)
 		{
 			foreach (TSPlayer player in TShock.Players)