using System;

using System.Numerics;

using System.Security.Cryptography;

public class Program

{

    public static void Main()

    {

        // Example to hash a password with SHA256 in C#

        HashAlgorithm sha256 = new SHA256Managed();

        // Splash screen.

        Console.WriteLine("Welcome to Huy's SHA256 Calculator!");

        Console.WriteLine("");

        // Takes an input.

        Console.Write("Please enter your input here:              ");

        string input = Console.ReadLine();

        Console.WriteLine("");

        // Maps your input, which is ASCII (plain text), into a UTF-8 byte array.

        byte[] plainTextBytes = System.Text.Encoding.UTF8.GetBytes(input);

        // Hashes your UTF-8 byte array with SHA256, the output is still UTF-8.

        byte[] hashBytes = sha256.ComputeHash(plainTextBytes);

​

        /* The array 'hashBytes' is now the hash output, in UTF-8 bytes, of your

           original input. We can now display this hash in a variety of formats. */

        // We display 'hashBytes' in base-64 format here.

        string base64Hash = Convert.ToBase64String(hashBytes);

        Console.WriteLine("This is your SHA256 output in base-64:     {0}", base64Hash);

        Console.WriteLine("");

        // We convert 'hashBytes' to hexadecimal format here.

        string hexHash = BitConverter.ToString(hashBytes);

        // Let's rid us of that pesky dash in the byte to hex conversion...

        hexHash = hexHash.Replace("-","");

        // My output in hex is verifiable via http://www.xorbin.com/tools/sha256-hash-calculator

        Console.WriteLine("This is your SHA256 output in hexadecimal: {0}", hexHash);

        // This loop changes each of the 32 bytes in the 'hashBytes' array into binary.

        string bitHash = "";

        for (int i = 0; i < 32; i++)

        {

            string utf8Byte = Convert.ToString(hashBytes[i], 2).PadLeft(8, '0');

            bitHash = bitHash.Insert((i*8), utf8Byte);

        }

        // We display 'hashBytes' in binary string here.

        string bitSubString1 = bitHash.Substring(0, 64);

        string bitSubString2 = bitHash.Substring(64, 64);

        string bitSubString3 = bitHash.Substring(128, 64);

        string bitSubString4 = bitHash.Substring(192, 64);

        Console.WriteLine("");

        Console.WriteLine("This is your SHA256 output in binary:      {0}", bitSubString1);

        Console.WriteLine("                                           {0}", bitSubString2);

        Console.WriteLine("                                           {0}", bitSubString3);

        Console.WriteLine("                                           {0}", bitSubString4);

        // This loop converts the binaries of 'bitHash' to integer.

        BigInteger integerHash = 0;

        for (int i = 0; i < 256; i++)

        {

            int bit = Int32.Parse(bitHash.Substring(i, 1));

            integerHash = integerHash + (bit * BigInteger.Pow(2, (255-i)));

        }

        // We display 'integerHash' in integer here.

        Console.WriteLine("");

        Console.WriteLine("This is your SHA256 output in integer:     {0}", integerHash);

    }

}