using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Security.Cryptography;

namespace BezpieczenstwoSystemowKomputerowych2103
{
    class Program
    {
        static void Main(string[] args)
        {
            string source = "Hello World!";
            using (MD5 md5Hash = MD5.Create())
            {
                string hash = GetMD5Hash(md5Hash, source);
                Console.WriteLine("The MD5 hash of: " + source + " is: " + hash + ".");
                Console.WriteLine("Veryfing the hash...");
                if (VerifyMd5Hash(md5Hash, source, hash))
                {
                    Console.WriteLine("The hashes are the same.");
                }
                else
                {
                    Console.WriteLine("The hashes are not the same.");
                }


            }
            Console.ReadKey();
        }

        static string GetMD5Hash(MD5 md5Hash, string input)
        {
            byte[] data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(input));
            StringBuilder sBuilder = new StringBuilder();
            for (int i = 0; i < data.Length; i++)
            {
                sBuilder.Append(data[i].ToString("x2"));
            }
            return sBuilder.ToString();

        }

        static bool VerifyMd5Hash(MD5 md5Hash, string input, string hash)
        {
            string hashOfInput = GetMD5Hash(md5Hash, input);
            StringComparer comparer = StringComparer.OrdinalIgnoreCase;
            if (0 == comparer.Compare(hashOfInput, hash))
            {
                return true;
            }
            else
            {
                return false;
            }

        }


        /*
        string source = ""; //f37981b90e71dcb98efa0539c8a5bbd4. //7215ee9c7d9dc229d2921a40e899ec5f
        using (MD5 md5Hash = MD5.Create())
        {
            string hash = GetMD5Hash(md5Hash, source);
            Console.WriteLine("The MD5 hash of: " + source + " is: " + hash + ".");
            Console.ReadKey();
        }

    }

    static string GetMD5Hash(MD5 md5Hash, string input) {
        byte[] data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(input));
        StringBuilder sBuilder = new StringBuilder();
        for (int i = 0; i < data.Length; i++) {
            sBuilder.Append(data[i].ToString("x2"));
        }
        return sBuilder.ToString();
    }

        /*
        const int totalRolls = 25000;
        int[] results = new int[6];
        for (int x = 0; x < totalRolls; x++)
        {
            byte roll = RollDice((byte)results.Length);
            results[roll - 1]++;
        }
        for (int i = 0; i < results.Length; ++i)
        {
            Console.WriteLine("{0}: {1} ({2:p1})", i + 1, results[i], (double)results[i] / (double)totalRolls);
        }
        Console.ReadKey();
    }

    public static byte RollDice(byte numberSides)
    {
        if (numberSides <= 0)
        {
            throw new ArgumentOutOfRangeException("numberSides");
        }
        RNGCryptoServiceProvider rngCsp = new RNGCryptoServiceProvider();
        byte[] randomNumber = new byte[1];
        do
        {
            rngCsp.GetBytes(randomNumber);
        } while (!isFairRoll(randomNumber[0], numberSides));
        return (byte)((randomNumber[0] % numberSides) + 1); 

    }

    private static bool isFairRoll(byte roll, byte numSides)
    {
        int fullSetsOfValeus = Byte.MaxValue / numSides;
        return roll < numSides * fullSetsOfValeus;
    }


    /*
    using (RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider())
    {
        byte[] data = new byte[4];                              //deklaracja tablicy bufora
        for (int i = 0; i < 10; i++)
        {
            rng.GetBytes(data);                                 //wypełnienie bufora
            int value = BitConverter.ToInt32(data, 0);          //konwersja to int32
            Console.WriteLine(value);
        }
    }

    /*
    byte[] bytes1 = new byte[100];
    byte[] bytes2 = new byte[100];
    Random rnd1 = new Random();
    Random rnd2 = new Random();

    rnd1.NextBytes(bytes1);
    rnd2.NextBytes(bytes2);

    Console.WriteLine("Pierwsza seria liczb: ");
    for (int ctr = bytes1.GetLowerBound(0); ctr <= bytes1.GetUpperBound(0); ctr++)
    {
        Console.Write("{0,5 }", bytes1[ctr]);
        if ((ctr + 1) % 10 == 0)
        {
            Console.WriteLine();
        }
    }

    Console.WriteLine("Druga seria liczb: ");
    for (int ctr = bytes2.GetLowerBound(0); ctr <= bytes2.GetUpperBound(0); ctr++)
    {
        Console.Write("{0,5 }", bytes2[ctr]);
        if ((ctr + 1) % 10 == 0)
        {
            Console.WriteLine();
        }
    }

    /*
    Random rand = new Random();

    Console.WriteLine("Pięc losowych liczb zmiennoprzecinkowych z zakresu 0-1: ");
    for (int ctr = 0; ctr <= 4; ctr++)
    {
        Console.WriteLine("{0,8:N3}", rand.NextDouble());
    }
    Console.WriteLine();
    /*
    Random rand = new Random();

    Console.Write("Pięc losowych liczb całkowitych z zakresu 0-100");
    for (int i = 0; i < 5; i++)
    {
        Console.Write("{0,8:N0}", rand.Next(101));
    }
    Console.WriteLine();
    /*
    Random r = new Random();
    int randomNumber = r.Next(1, 100);
    Console.Write("Liczba losowa wynosi: {0}", randomNumber);
    */

        //Console.ReadKey();
    }
}