Columnar.cs

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

namespace SecurityLibrary
{
    public class Columnar : ICryptographicTechnique<string, List<int>>
    {
        public List<int> Analyse(string plainText, string cipherText)
        {
            throw new NotImplementedException();
        }

    


        public string Decrypt(string cipherText, List<int> key)
        {
            cipherText = cipherText.ToUpper();
            int x = cipherText.Length;
            if (x % key.Count == 0)
            {
            }
            else
            {
                x += key.Count;
            }
            double col = x / key.Count;
            int c = (int)(col);
            string finalll = "";
            char[,] enc = new char[c, key.Count];
            int k = 0;
            int tmp = 0;
            for (int i = 0; i < key.Count; i++)
            {
                k = key.IndexOf(i + 1);

                for (int j = 0; j < col; j++)
                {
                    if (tmp < cipherText.Length)
                    {
                        enc[j, k] = cipherText[tmp];
                        tmp++;
                    }
                }
            }
            for (int i = 0; i < col; i++)
            {
                for (int j = 0; j < key.Count; j++)
                {
                    finalll = finalll + enc[i, j];
                }
            }


            return finalll.ToUpper();
        }

        public string Encrypt(string plainText, List<int> key)
        {
            int columns = key.Count;
            int rows = (int)Math.Ceiling((double)plainText.Length / columns);
            if (plainText.Length != rows * columns)
            {
                int x = (rows * columns) - plainText.Length;
                string appender = new string('x',x);
                plainText += appender;
            }
            List<List<char>> table = new List<List<char>>();
            Dictionary<int, string> cip = new Dictionary<int, string>();
            string CT = "";
            for (int i = 0; i < rows; i++)
            {
                table.Add(new List<char>());
            }

            int counter = 0;
            for (int i = 0; i < rows; i++)
            {
                for (int j = 0; j < columns && counter<plainText.Length; j++)
                {
                    table[i].Add(plainText[counter]);
                    counter++;
                }
            }

            for (int i = 0; i < columns; i++)
            {
                string tmp = "";
                for (int j = 0; j < rows; j++)
                {
                    tmp += table[j][i];
                    cip[key[i] ] = tmp;
                }
            }

            for (int i = 1; i <= cip.Count; i++)
            {
                CT += cip[i];
            }
            Console.WriteLine(CT);
            return CT.ToUpper();
        }
    }
}