using System;
using System.Runtime.InteropServices;
using System.IO;

public delegate uint ExportCallback(IntPtr pbData, [In, Out] MemoryStream memstr, uint cbData);

public class RawEFS {

    [DllImport("advapi32")]
    public static extern uint OpenEncryptedFileRaw(String filename, uint ulFlags, ref IntPtr pvContext); 

    [DllImport("advapi32")]
      public static extern uint ReadEncryptedFileRaw(ExportCallback fcback, MemoryStream memstr, IntPtr pvContext ); 

    [DllImport("advapi32")]
    public static extern void CloseEncryptedFileRaw(IntPtr pvContext); 

 static uint ERROR_SUCCESS = 0;

    public static void Main(String[] args) 
    {
	IntPtr pCntxt = IntPtr.Zero;

	if(args.Length == 0)
		return;
	String filename = args[0];

	if (filename == "")  //exit while(true) loop
		return;
	if (!File.Exists(filename)) {
		Console.WriteLine("File \"{0}\" does not exist!\n", filename);
		return;	
	}

	uint openresult = OpenEncryptedFileRaw( filename, 0, ref pCntxt);
	if(openresult != ERROR_SUCCESS){
		Console.WriteLine("Failed to open encrypted file '{0}'", filename);
		return;
	}
	else
		Console.WriteLine("Opened EFS encrypted file '{0}'", filename) ;

	ExportCallback myCallback = new ExportCallback(RawEFS.DumpEFS);
	MemoryStream memstr = new MemoryStream(4000) ;
	ReadEncryptedFileRaw(myCallback, memstr, pCntxt) ; //get raw efs file data and write to MemoryStream
	byte[] rawefsdata = memstr.ToArray();
	memstr.Close();
	if(openresult == ERROR_SUCCESS)
		CloseEncryptedFileRaw(pCntxt);
	ShowBytes("\n\nEncrypted EFS raw data", rawefsdata) ;
	PutFileBytes("_rawEFSdata", rawefsdata, rawefsdata.Length) ;
    }

   public static uint DumpEFS(IntPtr pbData, MemoryStream memstr,  uint cbData) { 
	byte[] data = new byte[cbData];
	Marshal.Copy(pbData, data, 0, (int)cbData) ;
	memstr.Write(data, 0, (int) cbData) ;
	return ERROR_SUCCESS ;
    }



private static void ShowBytes(String info, byte[] data){
  Console.WriteLine("{0}  [{1} bytes]", info, data.Length);
  for(int i=1; i<=data.Length; i++){	
	Console.Write("{0:X2}  ", data[i-1]) ;
	if(i%16 == 0)
	 Console.WriteLine();
	}
  Console.WriteLine("\n\n");
  }


 private static void PutFileBytes(String outfile, byte[] data, int bytes) {
  FileStream fs = null;
	if(bytes > data.Length) {
	   Console.WriteLine("Too many bytes");
	   return;
	  }
	try{
	 fs = new FileStream(outfile, FileMode.Create);
	 fs.Write(data, 0, bytes);
	}
	catch(Exception e) {
	 Console.WriteLine(e.Message) ; 
	}
	finally {
	 fs.Close();
	}
  }

}