<%@ WebHandler Language="C#" Class="PrepararFirma" %>

using FirmaDigitalAv;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;

public class PrepararFirma : IHttpHandler, System.Web.SessionState.IRequiresSessionState {

    public void ProcessRequest(HttpContext context)
    {
        string errorMsg = string.Empty;
        string dataToSign = string.Empty;

        // parameters
        string FormXML = context.Request["FormXML"];
        string Certificate = context.Request["Certificate"];

        try
        {
            using (FirmaDigitalAvSvcClient cliente = new FirmaDigitalAvSvcClient())
            {
                if (cliente.PrepararFirmaDigitalCades(
                    FormXML,
                    Certificate,
                    EsXp(context),
                    out dataToSign,
                    out errorMsg
                    
                    
                    
                    ))
                {
                    context.Response.Clear();
                    context.Response.ContentType = "application/xml";
                    context.Response.Write(dataToSign);
                }
                else
                {
                    context.Response.Clear();
                    context.Response.ContentType = "text/plain";
                    context.Response.Write(errorMsg);
                }
            }
        }
        catch (Exception e)
        {
            errorMsg = "Falló el llamado al servidor de firma digital";
            while (e != null)
            {
                errorMsg += (string.IsNullOrEmpty(errorMsg) ? "" : ": ") + e.Message;
                e = e.InnerException;
            }

            context.Response.Clear();
            context.Response.ContentType = "text/plain";
            context.Response.Write(errorMsg);
        }
    }

    /// <summary>
    /// Retorna true si el sistema operativo cliente es Windows XP
    /// </summary>
    private static bool EsXp(HttpContext context)
    {
        return context.Request.UserAgent.ToUpper().IndexOf("WINDOWS NT 5.1") > 0;
    }

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }

}