using System;

using System.Globalization;

using System.Text;

using System.IO;

using System.Security.Cryptography;

​

// From: Colin Pickard <colinp@chaseits.co.uk>

// To: Aaron Trewern <aaron.trewern@chaseits.co.uk>

// Date: Wed, 23 Oct 2013 13:02:35 +0000

// Message-ID: <cf174c0df2c13a11b529a59ad05285042a01c9788c283b5575844d3d5462659e@aaron.trewern.gmail.com>

// Subject: A Subject

// 

// Plain text body.

​

// 2013-10-23T13:02:35.0000000Z

// FROM:Colin Pickard <colinp@chaseits.co.uk>

// SUBJECT:A Subject

// SENT DATE:

// RECIPIENTS:To:[Aaron Trewern <aaron.trewern@chaseits.co.uk>] CC:[] BCC:[]

// BODY:Plaintextbody.

// ATTACHMENTS:

//

//

// 000C74CB0581854616FDC1C5E69EAF2606B782AF4037D6FE1EED2648834AA4F6

​

public class Program

{

    public static void Main()

    {

        DateTime result;

        //string s = "Wed, 23 Oct 2013 13:02:35 +0000";

        string s = "Wed, 17 May 2000 19:32:47 -0400";

        if (DateTime.TryParse(s, new CultureInfo("en-US"), DateTimeStyles.AdjustToUniversal, out result))

        {

            Console.WriteLine("{0}", result.ToString("o"));

        }

​

        string str = String.Format("FROM:{0}\r\nSUBJECT:{1}\r\nSENT DATE:{2}\r\nRECIPIENTS:{3}\r\nBODY:{4}\r\nATTACHMENTS:\r\n{5}\r\n", 

                                   "Colin Pickard <colinp@chaseits.co.uk>", 

                                   "A Subject", 

                                   "", // "2013-10-23T13:02:35.0000000Z",

                                   "To:[Aaron Trewern <aaron.trewern@chaseits.co.uk>] CC:[] BCC:[]", 

                                   "Plaintextbody.",

                                   "");

        string hash = ComputeSha256Hash(str, Encoding.UTF8);

        Console.WriteLine("{0}", str);

        Console.WriteLine("{0}", hash);

    }

​

    public static string ComputeSha256Hash(Stream stream)

    {

        using (SHA256 shA256 = SHA256.Create())

            return BitConverter.ToString(shA256.ComputeHash(stream)).Replace("-", "");

    }

​

    public static string ComputeSha256Hash(string textToHash, Encoding encoding)

    {

        using (MemoryStream memoryStream = new MemoryStream(encoding.GetBytes(textToHash)))

            return ComputeSha256Hash((Stream)memoryStream);

    }

}