/// <summary>
/// Requests authentication from the user.
/// </summary>
/// <param name="realm">Host/domain name that the server hosts.</param>
/// <remarks>
/// Used when calculating hashes in Digest authentication.
/// </remarks>
/// <seealso cref="DigestAuthentication"/>
/// <seealso cref="DigestAuthentication.GetHA1"/>
protected virtual void RequestAuthentication(string realm)
{
AuthenticationProvider.CreateChallenge(HttpContext.Current.Response, realm);
}