Rayman 2 Save Encryption Checker

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Rayman2SaveEncryption {
  class Program {

    static bool breakTheMold;
    static byte checkByte = 0;
    static uint checkDWord = 0;
    static uint importantSaveThing2 = 0;
    static byte importantSaveThing = 87;

    static void Main(string[] args) {
      if (args.Length > 0 || true) {
        //FileStream stream = File.OpenRead(args[0]);
        FileStream stream = File.OpenRead("test.sav");
        read(stream);
        Console.WriteLine("CheckByte now is "+checkByte);
        Console.WriteLine("CheckDWord now is " + checkDWord);
        Console.ReadKey();
      }
      else {
        Console.WriteLine("Enter a filename as the first argument");
        Console.ReadKey();
      }
    }

    static int saveDecryptMagic_1(FileStream File) {
      int nextCharInFile; // esi@2
      int result; // eax@4
      byte v4; // ST00_1@5

      nextCharInFile = File.ReadByte();

      result = nextCharInFile;
      if (nextCharInFile != -1) {
        v4 = importantSaveThing++;
        result = nextCharInFile ^ (byte)fuckUpTheByte(v4) ^ 0xB9;
        checkByte -= (byte)result;
        ++importantSaveThing2;
      }
      return result;
    }

    static byte fuckUpTheByte(byte theByte) {
      byte result; // al@1
      byte v2; // dl@1
      byte v3; // esi@1

      result = 0;
      v2 = 0;
      v3 = 7;
      do {
        result = (byte)(result | ((theByte >> v2++) & 1) << v3--);
      }
      while (v2 < 8u);
      return result;
    }

    static byte __SETS__(int x) {
        return (byte)((x < 0) ? 1 : 0);
    }

    static byte __OFSUB__(int x, int y) {
      int y2 = y;
      byte sx = __SETS__(x);
      return (byte)((sx ^ __SETS__(y2)) & (sx ^ __SETS__(x - y2)));
    }

    static void decreaseDWordAndCheck() { // Rayman2.exe sub_48D610
      if (--checkDWord < 0) {
        breakTheMold = true;
      }
    }

    static void read(FileStream stream) {
      int cheese = -1;
      int v3 = 0;
      int v5 = 0;
      int v6 = 0;
      int v8 = 0;
      int v9 = 0;
      int v10 = 0;
      int someVar;

      checkByte = getOneByteAndXorWith53(stream);
      checkDWord = getFourBytesAndXorWith0x54555657(stream);

      Console.WriteLine("CheckByte was " + checkByte);
      Console.WriteLine("CheckDWord was " + checkDWord);

      if (!breakTheMold) {
        while (true) {
          if (cheese == -1) {
            someVar = saveDecryptMagic_1(stream);
            if (someVar == -1) {
              breakTheMold = true;
            }
            else {
              v3 = saveDecryptMagic_1(stream);
            }
          }
          else {
            v5 = saveDecryptMagic_1(stream);
            someVar = v5;
            if (v5 == -1) {
              v6 = 0;
              do {
                v6++;
                decreaseDWordAndCheck();
              } while (v6 < 8);
              breakTheMold = true;
            }
            else {
              v3 = saveDecryptMagic_1(stream);
              if (v3 == -1) {
                for (int i=0;i<v5; ++i) {
                    decreaseDWordAndCheck();
                }
                breakTheMold = true;
              }
              else {
                v8 = 0;
                do {
                  v8++;
                  decreaseDWordAndCheck();
                } while (v8 < 8);
              }
            }
          }
          if (breakTheMold) {
            break;
          }
          v9 = 0;
          do {
            if (v9 > 0) {
              v3 = saveDecryptMagic_1(stream);
            }
            v10 = v9 + 8;
            if ((__OFSUB__(v9, v9 + 8) ^ 1)!=0) {
              do {
                if ((((ulong)v3 >> 32) ^ (ulong)Math.Abs(v3) & 1) - ((ulong)v3 >> 32) == 1) {
                  saveDecryptMagic_1(stream); // don't store as we don't give a shit
                }

                ++v9;
                v3 /= 2;
              }
              while (v9 < v10);
            }
            v9 = v10;
          }
          while (v10 < 8);
          if (breakTheMold) {
            break;
          }
          cheese = someVar;
        }
      }
    }

    private static uint getFourBytesAndXorWith0x54555657(FileStream stream) {
      byte[] DstBuf = new byte[4];
      stream.Read(DstBuf, 0, 4);
      int value = BitConverter.ToInt32(DstBuf, 0);
      return (uint)(value ^ 0x54555657);
    }

    private static byte getOneByteAndXorWith53(FileStream stream) {
      byte[] DstBuf = new byte[4];
      byte value = (byte)stream.ReadByte();
      return (byte)(value ^ 0x53);
    }
  }
}