C# Tutorial "Symmetric Cryptography" : Exercise: Handling any length text

Symmetric Cryptography

Exercise: Handling any length text

In practice message could be of any length. Sometimes you need add missing bits/bytes to end of last block.

Please don't change variable text and make the code work.

using System;
using System.Text;
using System.Linq;
					
public class Program
{
	public const int BLOCK_SIZE = 4; //4Bytes
		
	public static void Main()
	{
			var text =
				"Symmetric algorithms are pretty fast.";

			var result = GetBlocks(text);

			var output = String.Join(" ", result);

			Console.Write(output);

	}

	public static uint[] GetBlocks(string text)
	{
					
			var bytes = Encoding.ASCII.GetBytes(text);

			var blocksCount = (int)Math.Ceiling(bytes.Count() / (double)BLOCK_SIZE);

			var result = new uint[blocksCount];

			for (int i = 0; i < blocksCount; i++)
			{
				result[i] = ToUInt32(bytes.Skip(i * BLOCK_SIZE).Take(BLOCK_SIZE).ToArray());
			}

			return result;
	}
	
	public static UInt32 ToUInt32(byte[] bytes)
		{
			UInt32 result = 0;


			for (int i = 0; i < 4; i++)
			{
				result += (UInt32) Math.Pow(256, 3 - i)*bytes[i];
			}

			return result;
		}
}