blowdart

        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)
        {
            if (request.Headers.Date == null)
            {
                request.Headers.Date = DateTime.UtcNow;
            }

            // Check if we have request content, if we do then we need to add a Content-MD5 header.
            if (request.Content != null && request.Content.Headers.ContentMD5 == null)
            {

blowdart

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

namespace CryptoTest
{
    class Program
    {
        static void Main(string[] args)