Is it possible to transfer authentication from Webbrowser to WebRequest

If the question is only “How to transfer Webbrowser authentication information to Webrequest or Webclient?” this code is enough:

You can call the GetUriCookieContainer method that returns you a CookieContainer that can be used for subsequent call with WebRequest object.

  [DllImport("wininet.dll", SetLastError = true)]
    public static extern bool InternetGetCookieEx(
        string url, 
        string cookieName, 
        StringBuilder cookieData, 
        ref int size,
        Int32  dwFlags,
        IntPtr  lpReserved);

    private const Int32 InternetCookieHttponly = 0x2000;

/// <summary>
/// Gets the URI cookie container.
/// </summary>
/// <param name="uri">The URI.</param>
/// <returns></returns>
public static CookieContainer GetUriCookieContainer(Uri uri)
{
    CookieContainer cookies = null;
    // Determine the size of the cookie
    int datasize = 8192 * 16;
    StringBuilder cookieData = new StringBuilder(datasize);
    if (!InternetGetCookieEx(uri.ToString(), null, cookieData, ref datasize, InternetCookieHttponly, IntPtr.Zero))
    {
        if (datasize < 0)
            return null;
        // Allocate stringbuilder large enough to hold the cookie
        cookieData = new StringBuilder(datasize);
        if (!InternetGetCookieEx(
            uri.ToString(),
            null, cookieData, 
            ref datasize, 
            InternetCookieHttponly, 
            IntPtr.Zero))
            return null;
    }
    if (cookieData.Length > 0)
    {
        cookies = new CookieContainer();
        cookies.SetCookies(uri, cookieData.ToString().Replace(';', ','));
    }
    return cookies;
}