using System;

using System.Text;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        //Console.WriteLine("Hello World");

        SorguDecrypt decrypter = new SorguDecrypt();

        string enc = decrypter.Encode("HARUN");

        //string enc = "HL95q4pT84D1H4H5Kzq";

        string dec = decrypter.Decode(enc);

        Console.WriteLine("{0}: {1}", enc, dec);

    }

}

​

public class SorguDecrypt

{

    // Şifrelenmiş veri alfabesi

    private char[] outAlphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz/++".ToCharArray();

    // Şifrelenmemiş veri alfabesi (ISO-8859-9)

    private char[] inAlphabet = null;

    private Encoding turkishEncoding = null;

    public SorguDecrypt()

    {

        turkishEncoding = Encoding.GetEncoding("iso-8859-9");

        var bytes = Enumerable.Range(0, 255).Select(a => (byte)a).ToArray();

        inAlphabet = turkishEncoding.GetChars(bytes);

    }

​

    public string Encode(string clearText)

    {

        if (String.IsNullOrEmpty(clearText))

            return String.Empty;

        StringBuilder encodedString = new StringBuilder();

        clearText = clearText.PadRight(((clearText.Length - 1) / 3 + 1) * 3, (char)0);

        for (int j = 0; j < clearText.Length; j += 3)

        {

            var bytes = turkishEncoding.GetBytes(clearText.Substring(j, 3));

            int c1 = (int)(bytes[0]);

            int c2 = (int)(bytes[1]);

            int c3 = (int)(bytes[2]);

            int k1 = (c1) / 4;

            int k2 = (c1) % 4;

            int k3 = (c2) / 16;

            int k4 = (c2) % 16;

            int k5 = (c3) / 64;

            int k6 = (c3) % 64;

            char ec1 = outAlphabet[k1];

            char ec2 = outAlphabet[k3 + k2 * 16];

            char ec3 = outAlphabet[k5 + k4 * 4];

            char ec4 = outAlphabet[k6];

            encodedString.Append(ec1);

            encodedString.Append(ec2);

            if (c2 != 0)

                encodedString.Append(ec3);

            if (c3 != 0)

                encodedString.Append(ec4);

        }

​

        return encodedString.ToString();

    }

​

    public string Decode(string cipherText)

    {

        if (String.IsNullOrEmpty(cipherText))

            return String.Empty;

        StringBuilder decodedString = new StringBuilder();

        cipherText = cipherText.PadRight(((cipherText.Length - 1) / 4 + 1) * 4, (char)0);

        for (int j = 0; j < cipherText.Length; j += 4)

        {

            string s = cipherText.Substring(j, 4);

            int c1 = Array.IndexOf(outAlphabet, (s[0]));

            int c2 = Array.IndexOf(outAlphabet, (s[1])) + (s[0] == '/' ? 64 : 0);

            int c3 = Array.IndexOf(outAlphabet, (s[2])) + (s[1] == '/' ? 64 : 0);

            int c4 = Array.IndexOf(outAlphabet, (s[3])) + (s[2] == '/' ? 64 : 0);

            int r1 = (c2 * 16) / 255;

            int r2 = (c3 * 64) / 255;

            char dc1 = inAlphabet[(c1 * 4 + r1)];

            char dc2 = inAlphabet[((c2 * 16 + r2) % 256)];

            int r3 = Math.Min(254, (c3 - Array.IndexOf(inAlphabet, dc2) % 16 * 4) % 64 * 64 + c4);

            char dc3 = c4 != -1 ? inAlphabet[r3] : (char)0;

            decodedString.Append((dc1));

            if (c3 != -1)

                decodedString.Append((dc2));

            if (c4 != -1)

                decodedString.Append((dc3));

        }

​

        return decodedString.ToString();

    }

​

    public static void Test()

    {

        SorguDecrypt decrypter = new SorguDecrypt();

        string enc = decrypter.Encode("DENEME");

        string dec = decrypter.Decode(enc);

        Console.WriteLine("{0}: {1}", enc, dec);

    }

}