Program.cs

// Decompiled with JetBrains decompiler
// Type: BadMorals.Program
// Assembly: BadMorals, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
// MVID: EFA47BB4-3A3A-492E-AB54-EE96FB30AF03
// Assembly location: D:\hackvent-2020\7\cc1b4db7-d5b6-48b8-bee5-8dcba508bf81.exe

using System;
using System.Security.Cryptography;
using System.Text;

namespace BadMorals
{
  public class Program
  {
    public static void Main(string[] args)
    {
      try
      {
        Console.Write("Your first input: ");
        char[] charArray1 = Console.ReadLine().ToCharArray();
        string str1 = "";
        for (int index = 0; index < charArray1.Length; ++index)
        {
          if (index % 2 == 0 && index + 2 <= charArray1.Length)
            str1 += charArray1[index + 1].ToString();
        }
        string str2;
        Console.WriteLine(str1);
        if (str1 == "BumBumWithTheTumTum")
        {
          str2 = "SFYyMH" + charArray1[17].ToString() + "yMz" + (object) (charArray1[8].GetHashCode() % 10) + "zcnMzXzN" + charArray1[3].ToString() + "ZzF" + charArray1[9].ToString() + "MzNyM" + charArray1[13].ToString() + "5n" + charArray1[14].ToString() + "2";
        }
        else
        {
          if (str1 == "")
          {
            Console.WriteLine("Your input is not allowed to result in an empty string");
            return;
          }
          str2 = str1;
        }
        Console.Write("Your second input: ");
        char[] charArray2 = Console.ReadLine().ToCharArray();
        string str3 = "";
        Array.Reverse((Array) charArray2);
        for (int index = 0; index < charArray2.Length; ++index)
          str3 += charArray2[index].ToString();
        string s;
        if (str3 == "BackAndForth")
        {
          s = "Q1RGX3" + charArray2[11].ToString() + "sNH" + charArray2[8].ToString() + "xbm" + charArray2[5].ToString() + "f";
        }
        else
        {
          if (str3 == "")
          {
            Console.WriteLine("Your input is not allowed to result in an empty string");
            return;
          }
          s = str3;
        }
        Console.Write("Your third input: ");
        char[] charArray3 = Console.ReadLine().ToCharArray();
        string str4 = "";
        byte num = 42;
        for (int index = 0; index < charArray3.Length; ++index)
        {
          char ch = (char) ((uint) charArray3[index] ^ (uint) num);
          num = (byte) ((int) num + index - 4);
          str4 += ch.ToString();
        }
        string str5;
        if (str4 == "DinosAreLit")
        {
          str5 = "00ZD" + charArray3[3].ToString() + "f" + charArray3[2].ToString() + "zRzeX0=";
        }
        else
        {
          if (str4 == "")
          {
            Console.WriteLine("Your input is not allowed to result in an empty string");
            return;
          }
          str5 = str4;
        }
        byte[] bytes = Convert.FromBase64String(str2 + str5);
        byte[] numArray1 = Convert.FromBase64String(s);
        byte[] buffer = new byte[bytes.Length];
        for (int index = 0; index < bytes.Length; ++index)
          buffer[index] = (byte) ((uint) bytes[index] ^ (uint) numArray1[index % numArray1.Length]);
        byte[] hash = SHA1.Create().ComputeHash(buffer);
        byte[] numArray2 = new byte[20]
        {
          (byte) 107,
          (byte) 64,
          (byte) 119,
          (byte) 202,
          (byte) 154,
          (byte) 218,
          (byte) 200,
          (byte) 113,
          (byte) 63,
          (byte) 1,
          (byte) 66,
          (byte) 148,
          (byte) 207,
          (byte) 23,
          (byte) 254,
          (byte) 198,
          (byte) 197,
          (byte) 79,
          (byte) 21,
          (byte) 10
        };
        for (int index = 0; index < hash.Length; ++index)
        {
          if ((int) hash[index] != (int) numArray2[index])
          {
            Console.WriteLine("Your inputs do not result in the flag.");
            return;
          }
        }
        string str6 = Encoding.ASCII.GetString(bytes);
        if (!str6.StartsWith("HV20{"))
          return;
        Console.WriteLine("Congratulations! You're now worthy to claim your flag: {0}", (object) str6);
      }
      catch
      {
        Console.WriteLine("Please try again.");
      }
      finally
      {
        Console.WriteLine("Press enter to exit.");
        Console.ReadLine();
      }
    }
  }
}