// (c) 2006 Richard Grimes
// www.grimes.demon.co.uk
using System;
using System.IO;
using System.Security.Cryptography;

class App
{
   // Parameters: e|d infile outfile
   static void Main(string[] args)
   {
      if (args.Length < 3)
      {
         Console.WriteLine("Usage: protect e|d infile outfile");
         return;
      }

      bool bEncrypt = (args[0][0] == 'e');
      if (!File.Exists(args[1]))
      {
         Console.WriteLine("{0} does not exist", args[1]);
         return;
      }
      if (File.Exists(args[2]))
      {
         File.Delete(args[2]);
      }

      byte[] inData, outData;

      using (FileStream fsIn = File.OpenRead(args[1]))
      {
         inData = new byte[fsIn.Length];
         fsIn.Read(inData, 0, inData.Length);
      }

      if (bEncrypt)
         outData = ProtectedData.Protect(inData, null, DataProtectionScope.CurrentUser);
      else
         outData = ProtectedData.Unprotect(inData, null, DataProtectionScope.CurrentUser);

      using (FileStream fsOut = File.OpenWrite(args[2]))
      {
         fsOut.Write(outData, 0, outData.Length);
      }
   }
}