Example Epoints Web Service (EWS) Client Connection Code in C#

ews-client.cs

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

//This is an example how to interact with Epoints API using C# Script execution engine (http://www.csscript.net/)
class Script
{

        static void Main()
        {
		    HttpWebRequest request = IatRequest(
		        "https://qa-api.epoints.com/transactions?action=getThisMonthSpent&apiKey=<YOUR_API_KEY>",
		        "<YOUR_API_KEY>",
		        "<YOUR_HMAC_KEY>"
		    );
		    WriteResponse(request.GetResponse() as HttpWebResponse);
        }

        static HttpWebRequest IatRequest(string url, string iatId, string secret)
        {
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.Method = "GET";
            WebHeaderCollection headers = (request as HttpWebRequest).Headers;
            string httpDate = DateTime.UtcNow.ToString("yyyyMMddHHmmssfff");
            headers.Add("x-iat-date", httpDate);
            string canonicalString = "GET\n" + httpDate + "\n" + request.RequestUri.AbsolutePath;
			KeyedHashAlgorithm hash = KeyedHashAlgorithm.Create("HmacSHA256");
            hash.Key = Encoding.UTF8.GetBytes(secret);
            byte[] bytes  = Encoding.UTF8.GetBytes(canonicalString);
            byte[] signature = hash.ComputeHash(bytes);
            string encodedSignature = Convert.ToBase64String(signature);
            headers.Add("Authorization", "IAT " + iatId + ":" + encodedSignature);
            return request;
        }

         static void WriteResponse(HttpWebResponse response)
         {
            Stream stream =  response.GetResponseStream() as Stream;
            byte[] buffer = new byte[32 * 1024];
            int nRead =0;
            MemoryStream ms = new MemoryStream();
            do
            {
                nRead = stream.Read(buffer, 0, buffer.Length);
                ms.Write(buffer, 0, nRead);
            } while (nRead > 0);
            ASCIIEncoding encoding = new ASCIIEncoding();
            string responseString = encoding.GetString(ms.ToArray());
         	System.Console.WriteLine("\r\nHeaders:");
         	for(int i=0; i < response.Headers.Count; ++i)
         	    System.Console.WriteLine("{0} :{1}",response.Headers.Keys[i],response.Headers[i]);
            System.Console.WriteLine("\nResponse:");
            System.Console.Write(responseString);
         	response.Close();
         }
}