A simple proxy in C# which persists the entire request to the target

proxy.ashx

<%@ WebHandler Language="C#" CodeBehind="proxy.ashx.cs" Class="PIPE.Host.proxy" %>

proxy.ashx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Net;
using System.IO;
using System.Text;

namespace PIPE.Host
{
    public class proxy : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            string serviceUrl = string.Empty;
            if(!string.IsNullOrEmpty(context.Request.QueryString["url"])) {
                serviceUrl = context.Request.QueryString["url"];
            }
            else if(!string.IsNullOrEmpty(context.Request.Params["url"]))
            {
                serviceUrl = context.Request.Form["url"];
            } else {
                context.Response.Write("no url given.");
                return;
            }

            string query = string.Empty;
            bool firstelement = true;

            // Copy GET vars
            foreach (string key in context.Request.QueryString)
            {
                if (key == "url") continue;
                query += (firstelement ? "?" : "&") + key + "=" + context.Request.QueryString[key];
                if (firstelement) firstelement = false;
            }

            serviceUrl = serviceUrl + query;

            HttpWebRequest client = (HttpWebRequest)WebRequest.Create(serviceUrl);
            client.KeepAlive = false;
            client.Method = context.Request.HttpMethod;
            client.ContentType = HttpContext.Current.Request.ContentType;

            // Since we pass headers through untouched, we might get compressed data back. To do anything with it we need to deflate it
            client.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip;

            // Copy header properties
            foreach (string headerKey in HttpContext.Current.Request.Headers.Keys)
            {
                try
                {
                    client.Headers[headerKey] = HttpContext.Current.Request.Headers[headerKey];
                }
                catch (Exception ex)
                {
                    System.Diagnostics.Debug.WriteLine(ex.Message);
                }
            }

            // Copy POST vars
            string post_str = string.Empty;
            firstelement = true;
            foreach (string key in context.Request.Form.Keys)
            {
                if (key == "url") continue;
                post_str += (firstelement ? "" : "&") + key + "=" + context.Request.Form[key];
                firstelement = false;
            }
            if (!string.IsNullOrEmpty(post_str))
            {
                byte[] data = new ASCIIEncoding().GetBytes(post_str);
                client.ContentLength = data.Length; // fix the content length after removing the target url
                client.GetRequestStream().Write(data, 0, data.Length);
            }

            client.GetResponse().GetResponseStream().CopyTo(context.Response.OutputStream);
        }


        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}