rsa

using System;
using System.Security.Cryptography;
using System.Text;
using System.Collections.Generic;
using System.IO;

class RSACSPSample
{

    static void Main()
    {

        try
        {
            //Create a UnicodeEncoder to convert between byte array and string.
            UnicodeEncoding ByteConverter = new UnicodeEncoding();

            Console.Write("Enter A Text To Encrypt: ");
            string onevs1 = Console.ReadLine();
            //Create byte arrays to hold original, encrypted, and decrypted data.
            byte[] dataToEncrypt = ByteConverter.GetBytes(onevs1);
            byte[] encryptedData;
            byte[] decryptedData;

            //Create a new instance of RSACryptoServiceProvider to generate
            //public and private key data.
            using (RSACryptoServiceProvider RSA = new RSACryptoServiceProvider())
            {
                encryptedData = RSAEncrypt(dataToEncrypt, RSA.ExportParameters(false), false);
                // decryptedData = RSADecrypt(encryptedData, RSA.ExportParameters(true), false);
                var cypherText = Convert.ToBase64String(encryptedData);
                Console.WriteLine("Eecrypted plaintext: {0}", cypherText);
                Console.WriteLine();
                var ChyperUser = Console.ReadLine();
                byte[] decData = Base64Decode(ChyperUser);
                decryptedData = RSADecrypt(decData, RSA.ExportParameters(true), false);
                Console.WriteLine("Decrypted plaintext: {0}", ByteConverter.GetString(decryptedData));


            }
        }
        catch (Exception e)
        {
            //Catch this exception in case the encryption did
            //not succeed.
            Console.WriteLine("Encryption failed.");

        }
    }
    public static byte[] Base64Decode(string base64EncodedData)
    {
        return Convert.FromBase64String(base64EncodedData);

    }

    static public byte[] RSAEncrypt(byte[] DataToEncrypt, RSAParameters RSAKeyInfo, bool DoOAEPPadding)
    {
        try
        {
            byte[] encryptedData;
            //Create a new instance of RSACryptoServiceProvider.
            using (RSACryptoServiceProvider RSA = new RSACryptoServiceProvider())
            {

                //Import the RSA Key information. This only needs
                //toinclude the public key information.
                RSA.ImportParameters(RSAKeyInfo);

                //Encrypt the passed byte array and specify OAEP padding.
                //OAEP padding is only available on Microsoft Windows XP or
                //later.
                encryptedData = RSA.Encrypt(DataToEncrypt, DoOAEPPadding);
            }
            return encryptedData;
        }
        //Catch and display a CryptographicException
        //to the console.
        catch (CryptographicException e)
        {
            Console.WriteLine(e.Message);

            return null;
        }

    }
    static public byte[] RSADecrypt(byte[] DataToDecrypt, RSAParameters RSAKeyInfo, bool DoOAEPPadding)
    {
        try
        {
            byte[] decryptedData;
            //Create a new instance of RSACryptoServiceProvider.
            RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
            //Import the RSA Key information. This needs
            //to include the private key information.
            RSA.ImportParameters(RSAKeyInfo);
            //Decrypt the passed byte array and specify OAEP padding.
            //OAEP padding is only available on Microsoft Windows XP or
            //later.
            decryptedData = RSA.Decrypt(DataToDecrypt, DoOAEPPadding);
            return decryptedData;
        }
        //Catch and display a CryptographicException
        //to the console.
        catch (CryptographicException e)
        {
            Console.WriteLine(e.ToString());

            return null;
        }

    }
}