using System;
using DotNetNuke.Entities.Modules;
using System.Net;

namespace ReportServicesViewer
{
    public partial class View : PortalModuleBase
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            ReportViewer1.Width = 500;
            ReportViewer1.Height = 500;
            ReportViewer1.ProcessingMode = Microsoft.Reporting.WebForms.ProcessingMode.Remote;
            Microsoft.Reporting.WebForms.IReportServerCredentials irsc =
                new CustomReportCredentials("ReportUser", "password", "Mydomain");
            ReportViewer1.ServerReport.ReportServerCredentials = irsc;
            ReportViewer1.ServerReport.ReportServerUrl = new Uri(@"http://localhost/ReportServer/");
            ReportViewer1.ServerReport.ReportPath = "/Models/EventLogReport";
            ReportViewer1.ServerReport.Refresh();
        }
    }
}

public class CustomReportCredentials : Microsoft.Reporting.WebForms.IReportServerCredentials
{
    // From: http://community.discountasp.net/default.aspx?f=14&m=15967
    // local variable for network credential.
    private string _UserName;
    private string _PassWord;
    private string _DomainName;
    public CustomReportCredentials(string UserName, string PassWord, string DomainName)
    {
        _UserName = UserName;
        _PassWord = PassWord;
        _DomainName = DomainName;
    }
    public System.Security.Principal.WindowsIdentity ImpersonationUser
    {
        get
        {
            return null;  // not use ImpersonationUser
        }
    }
    public ICredentials NetworkCredentials
    {
        get
        {
            // use NetworkCredentials
            return new NetworkCredential(_UserName, _PassWord, _DomainName);
        }
    }
    public bool GetFormsCredentials(out Cookie authCookie, out string user,
        out string password, out string authority)
    {

        // not use FormsCredentials unless you have implements a custom autentication.
        authCookie = null;
        user = password = authority = null;
        return false;
    }
}