// (c) 2006 Richard Grimes
// www.grimes.demon.co.uk

using System;
using System.Security.Cryptography.Pkcs;
using System.Security.Cryptography.X509Certificates;
using System.IO;
using System.Text;

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

      bool encrypt = true;
      encrypt = (args[0].ToLower()[0] == 'e');

      string infile = args[1];
      if (!File.Exists(infile))
      {
         Console.WriteLine("{0} does not exist", infile);
         return;
      }

      string outfile = args[2];
      if (File.Exists(outfile))
      {
         File.Delete(outfile);
      }

      if (encrypt)
      {
	     string certname = args[3];
         X509Certificate2 cert = GetCertificate(certname);
         if (cert == null)
         {
            Console.WriteLine("No certificate with the name {0}", certname);
            return;
         }
         EncryptMsg(infile, outfile, cert);
      }
      else
      {
         DecryptMsg(infile, outfile);
      }
   }

   static X509Certificate2 GetCertificate(string certname)
   {
      X509Store store = new X509Store(StoreName.AddressBook, StoreLocation.CurrentUser);
      store.Open(OpenFlags.ReadOnly);
  
      X509Certificate2Collection certs =
         store.Certificates.Find(X509FindType.FindBySubjectName, certname, false);
      store.Close();
      if (certs.Count == 0) return null;
  
      return certs[0];
   }

   static void EncryptMsg(string infile, string outfile, X509Certificate2 cert)
   {
   }

   static void DecryptMsg(string infile, string outfile)
   {
   }
}