using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Security.Cryptography;
using System.Xml;
using System.IO;
/// <summary>
/// Summary description for Cryptography
/// </summary>
public class Cryptography1
{

public static RSACryptoServiceProvider rsa;
    public Cryptography1(string name)
  {
  }
  public static void AssignParameter()
  {
  const int PROVIDER_RSA_FULL = 1;
  const string CONTAINER_NAME = "mycontent";
  CspParameters cspParams;
  cspParams = new CspParameters(PROVIDER_RSA_FULL);
  cspParams.KeyContainerName = CONTAINER_NAME;
  cspParams.Flags = CspProviderFlags.UseMachineKeyStore;
  cspParams.ProviderName = "Microsoft Strong Cryptographic Provider";
  rsa = new RSACryptoServiceProvider(cspParams);
   }

   public static EncryptData(string Data2Encrypt)
   {
       AssignParameter();
      StreamReader reader =new StreamReader("Mypublickey.xml");          
     string l=reader.ReadToEnd();            
     rsa.FromXmlString(l);
     reader.Close();
    byte[] plainbytes = System.Text.Encoding.UTF8.GetBytes(data2Encrypt); 
    byte[] cipherbytes = rsa.Encrypt(plainbytes,false);
    return Convert.ToBase64String(cipherbytes);
    }
  public static void AssignNewKey()
   {
       AssignParameter();   
        //provide public and private RSA params
       StreamWriter writer = new StreamWriter("Myprivatekey.xml"); 
       string publickey = rsa.ToXmlString(true); 
      writer.Write(publicPrivateKeyXML);
      writer.Close();
     //provide public only RSA params
     writer = new StreamWriter("Mypublickey.xml");
     string publicOnlyKeyXML = rsa.ToXmlString(false);
     writer.Write(publicOnlyKeyXML); 
     writer.Close();
   }
  public static string DecryptData(string data2Decrypt)
   {   
     AssignParameter();
    byte[] getpassword = Convert.FromBase64String(data2Decrypt);
    StreamReader reader = new StreamReader("Myprivatekey.xml");
   string publicPrivateKeyXML = reader.ReadToEnd(); 
   rsa.FromXmlString(publicPrivateKeyXML);  
   reader.Close();
   //read ciphertext, decrypt it to plaintext
   byte[] plain =   rsa.Decrypt(getpassword,false);
   return System.Text.Encoding.UTF8.GetString(plain);
   }
}