From e3abf499ba304fb45e1d02316df1495bb83a3b4b Mon Sep 17 00:00:00 2001
From: Allex Rodrigues <allexxrodriguess@gmail.com>
Date: Mon, 28 Dec 2020 18:33:26 -0300
Subject: [PATCH] Changing CRC32 implementation

---
 UWPHook/Crc32.cs            | 48 -------------------------------------
 UWPHook/GamesWindow.xaml.cs |  5 ++--
 UWPHook/UWPHook.csproj      |  3 +++
 UWPHook/packages.config     |  1 +
 4 files changed, 7 insertions(+), 50 deletions(-)
 delete mode 100644 UWPHook/Crc32.cs

diff --git a/UWPHook/Crc32.cs b/UWPHook/Crc32.cs
deleted file mode 100644
index 7cf768f..0000000
--- a/UWPHook/Crc32.cs
+++ /dev/null
@@ -1,48 +0,0 @@
-using System;
-
-namespace UWPHook
-{
-    public class Crc32
-    {
-        uint[] table;
-
-        public uint ComputeChecksum(byte[] bytes)
-        {
-            uint crc = 0xffffffff;
-            for (int i = 0; i < bytes.Length; ++i)
-            {
-                byte index = (byte)(((crc) & 0xff) ^ bytes[i]);
-                crc = (uint)((crc >> 8) ^ table[index]);
-            }
-            return ~crc;
-        }
-
-        public byte[] ComputeChecksumBytes(byte[] bytes)
-        {
-            return BitConverter.GetBytes(ComputeChecksum(bytes));
-        }
-
-        public Crc32()
-        {
-            uint poly = 0xedb88320;
-            table = new uint[256];
-            uint temp = 0;
-            for (uint i = 0; i < table.Length; ++i)
-            {
-                temp = i;
-                for (int j = 8; j > 0; --j)
-                {
-                    if ((temp & 1) == 1)
-                    {
-                        temp = (uint)((temp >> 1) ^ poly);
-                    }
-                    else
-                    {
-                        temp >>= 1;
-                    }
-                }
-                table[i] = temp;
-            }
-        }
-    }
-}
diff --git a/UWPHook/GamesWindow.xaml.cs b/UWPHook/GamesWindow.xaml.cs
index 126b266..684308a 100644
--- a/UWPHook/GamesWindow.xaml.cs
+++ b/UWPHook/GamesWindow.xaml.cs
@@ -1,4 +1,5 @@
-using SharpSteam;
+using Force.Crc32;
+using SharpSteam;
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
@@ -112,7 +113,7 @@ namespace UWPHook
         private UInt64 GenerateSteamGridAppId(string appName, string appTarget)
         {
             byte[] nameTargetBytes = Encoding.UTF8.GetBytes(appTarget + appName + "");
-            UInt64 crc = new Crc32().ComputeChecksum(nameTargetBytes);
+            UInt64 crc = Crc32Algorithm.Compute(nameTargetBytes);
             UInt64 gameId = crc | 0x80000000;
 
             return gameId;
diff --git a/UWPHook/UWPHook.csproj b/UWPHook/UWPHook.csproj
index 7ac201b..6d4fa79 100644
--- a/UWPHook/UWPHook.csproj
+++ b/UWPHook/UWPHook.csproj
@@ -59,6 +59,9 @@
     <StartupObject>UWPHook.App</StartupObject>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="Crc32.NET, Version=1.0.0.0, Culture=neutral, PublicKeyToken=dc0b95cf99bf4e99, processorArchitecture=MSIL">
+      <HintPath>..\packages\Crc32.NET.1.2.0\lib\net20\Crc32.NET.dll</HintPath>
+    </Reference>
     <Reference Include="MaterialDesignColors, Version=1.2.6.1513, Culture=neutral, processorArchitecture=MSIL">
       <HintPath>..\packages\MaterialDesignColors.1.2.6\lib\net45\MaterialDesignColors.dll</HintPath>
     </Reference>
diff --git a/UWPHook/packages.config b/UWPHook/packages.config
index b43367d..804c406 100644
--- a/UWPHook/packages.config
+++ b/UWPHook/packages.config
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
+  <package id="Crc32.NET" version="1.2.0" targetFramework="net461" />
   <package id="MaterialDesignColors" version="1.2.6" targetFramework="net461" />
   <package id="MaterialDesignThemes" version="3.1.3" targetFramework="net461" />
   <package id="Microsoft.AspNet.WebApi.Client" version="5.2.7" targetFramework="net461" />