CRYPTAGE

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

namespace RMTools
{
  public static class Cryptage
  {
    public static void EncryptFile(string _sInFileName, string _sOutFileName, string sKey)
    {
      DES des = new DESCryptoServiceProvider(); //Vous pouvez changer service provider
      byte[] bs = new byte[8];
      for (int i = 0; i < des.Key.Length && i<sKey.Length; i++)
			{
        bs[i] = Convert.ToByte(sKey[i]);
			}
      des.Key = bs;
      des.IV = new byte[] { 1, 6, 10, 4, 2, 6, 7, 8 }; //Peut-être modifier

      FileStream fin = new FileStream(_sInFileName, FileMode.Open, FileAccess.Read);
      FileStream fout = new FileStream(_sOutFileName, FileMode.OpenOrCreate, FileAccess.Write);
      fout.SetLength(0);

      //Create variables to help with read and write.
      byte[] bin = new byte[100]; 
      long rdlen = 0;              
      long totlen = fin.Length;    
      int len;                     
      CryptoStream encStream = new CryptoStream(fout, des.CreateEncryptor(), CryptoStreamMode.Write);
      while (rdlen < totlen)
      {
        len = fin.Read(bin, 0, 100);
        encStream.Write(bin, 0, len);
        rdlen = rdlen + len;
      }
      encStream.Close();
      fout.Close();
      fin.Close();
    }


    public static bool DecryptFile(string _sInFileName, string _sOutFileName, string sKey)
    {
      DES des = new DESCryptoServiceProvider();

      byte[] bs = new byte[8];
      for (int i = 0; i < des.Key.Length && i < sKey.Length; i++)
      {
        bs[i] = Convert.ToByte(sKey[i]);
      }
      des.Key = bs;
      des.IV = new byte[] { 1, 6, 10, 4, 2, 6, 7, 8 }; 
      FileStream fin = new FileStream(_sInFileName, FileMode.Open, FileAccess.Read);
      FileStream fout = new FileStream(_sOutFileName, FileMode.OpenOrCreate, FileAccess.Write);
      fout.SetLength(0);

   
      byte[] bin = new byte[100]; 
      long rdlen = 0;              
      long totlen = fin.Length;    
      int len;                     


      CryptoStream encStream = new CryptoStream(fout, des.CreateDecryptor(), CryptoStreamMode.Write);

      while (rdlen < totlen)
      {
        len = fin.Read(bin, 0, 100);
        encStream.Write(bin, 0, len);
        rdlen = rdlen + len;
      }
      try
      {
        encStream.Close();
        fout.Close();
        fin.Close();
        return true;
      }
      catch
      {
        fout.Close();
        fin.Close();
        return false;
      }
      
      
    }
  }
}