using System;

using System.IO;

using System.Text;

using System.Security.Cryptography;

​

public class Program

{

    public static void Main()

    {

        RedCorona.Cryptography.PKCSKeyGenerator kp = new RedCorona.Cryptography.PKCSKeyGenerator();

ICryptoTransform crypt = kp.Generate(

      "MyPassword",

      new byte[] { 100, 200, 255, 3},  // salt

      15,             // iterations of MD5 hashing

      1 );  // number of 16-byte segments to create. 

            // 1 to mimic Java behaviour.

​

    }

}

​

//*************************************************************************

//

// PKCSKeyGenerator.cs

// Derive key material using PKCS #1 v1.5 algorithm with MD5 hash

//

// Portions Copyright (C) 2005.  Michel I. Gallant

// Portions copyright 2006 Richard Smith

// Adapted from http://www.jensign.com/JavaScience/dotnet/DeriveKeyM/index.html

//

//*************************************************************************

//

//  DeriveKeyM.cs

//

//  Derive a key from a pswd and Salt using MD5 and PKCS #5 v1.5 approach

//   see also:   http://www.openssl.org/docs/crypto/EVP_BytesToKey.html

//   see also:   http://java.sun.com/j2se/1.5.0/docs/guide/security/jce/JCERefGuide.html#PBE

//

//**************************************************************************

​

namespace RedCorona.Cryptography {

    public class PKCSKeyGenerator {

        byte[] key = new byte[8], iv = new byte[8];

        DESCryptoServiceProvider des = new DESCryptoServiceProvider();

        public byte[] Key { get { return key; } }

        public byte[] IV { get { return IV; } }

        public ICryptoTransform Encryptor { get { return des.CreateEncryptor(key, iv); } }

        public PKCSKeyGenerator(){}

        public PKCSKeyGenerator(String keystring, byte[] salt, int md5iterations, int segments){

            Generate(keystring, salt, md5iterations, segments);

        }

        public ICryptoTransform Generate(String keystring, byte[] salt, int md5iterations, int segments){

            int HASHLENGTH = 16;    //MD5 bytes

            byte[] keymaterial = new byte[HASHLENGTH*segments] ;     //to store contatenated Mi hashed results

            // --- get secret password bytes ----

            byte[] psbytes;

            psbytes = Encoding.UTF8.GetBytes(keystring);

            // --- contatenate salt and pswd bytes into fixed data array ---

            byte[] data00 = new byte[psbytes.Length + salt.Length] ;

            Array.Copy(psbytes, data00, psbytes.Length);        //copy the pswd bytes

            Array.Copy(salt, 0, data00, psbytes.Length, salt.Length) ;  //concatenate the salt bytes

            // ---- do multi-hashing and contatenate results  D1, D2 ...  into keymaterial bytes ----

            MD5 md5 = new MD5CryptoServiceProvider();

            byte[] result = null;

            byte[] hashtarget = new byte[HASHLENGTH + data00.Length];   //fixed length initial hashtarget

            for(int j=0; j<segments; j++) {

                // ----  Now hash consecutively for md5iterations times ------

                if(j == 0) result = data00;     //initialize

                else {

                    Array.Copy(result, hashtarget, result.Length);

                    Array.Copy(data00, 0, hashtarget, result.Length, data00.Length) ;

                    result = hashtarget;

                }

                for(int i=0; i<md5iterations; i++)

                    result = md5.ComputeHash(result);

                Array.Copy(result, 0, keymaterial, j*HASHLENGTH, result.Length);  //contatenate to keymaterial

            }

            Array.Copy(keymaterial, 0, key, 0, 8);

            Array.Copy(keymaterial, 8, iv, 0, 8);

            return Encryptor;

        }

    }

}

​