XOR Cipher

XORCipher.cs

using System;
using System.Text;

class program 
{
    static void Main(){
        string key = (string)"\xde\xad\xbe\xef\01";
        string str = "hogehoge", base64str, cryptedstr, decryptedstr;
        byte[] bs;

        cryptedstr = XORCrypt(str,key);
        bs = Encoding.UTF8.GetBytes(cryptedstr);
        base64str =  Convert.ToBase64String(bs);

        Console.WriteLine("crypted: {0}", cryptedstr);
        Console.WriteLine("base64: {0}", base64str);
        decryptedstr = XORDecrypt(cryptedstr,key);
        Console.WriteLine("raw: {0}", decryptedstr);
    }

    public static string XORCrypt(string toCrypt, string key)
    {
        string encrepted = "";
        int j = 0;
        for (int i = 0; i < toCrypt.Length; i++)
        {
            if(j==key.Length)
                j=0;
            encrepted += (Char)(toCrypt[i] ^ key[j++]);
        }
        return encrepted;
    }
    
    public static string XORDecrypt(string Encrypted, string key)
    {
        string decrypted = "";
        int j = 0;
        for (int i = 0; i < Encrypted.Length; i++)
        {
            if (j == key.Length)
                j = 0;
            decrypted += (Char)(Encrypted[i] ^ key[j++]);
        }
        return decrypted;
    }
}