/// <summary>
/// Validates authentication cookie and refreshes it if cookie is near to expiration time.
/// </summary>
/// <returns>User principal name if cookie is valid. Otherwise - null.</returns>
private static string GetPrincipalNameFromCookie(HttpContextBase httpContext)
{
HttpCookie principalCookie = httpContext.Request.Cookies.Get(AuthCookieName);
if (principalCookie == null || string.IsNullOrEmpty(principalCookie.Value))
{
return(null);
}
AuthenticationPackage authPackage = AuthenticationPackage.FromXml(principalCookie.Value);
if (authPackage == null)
{
return(null);
}
DateTime now = DateTime.UtcNow;
if (now > authPackage.Expires)
{
return(null);
}
else if (now >= authPackage.Expires.AddSeconds(-ConfiguraionProvider.AuthenticationCookieRefreshMargin))
{
SetAuthenticationCookie(httpContext, authPackage.PrincipalName);
}
return(authPackage.PrincipalName);
}
private static void SetAuthenticationCookie(HttpContextBase httpContext, string principalName)
{
AuthenticationPackage package = new AuthenticationPackage()
{
PrincipalName = principalName,
Expires = DateTime.UtcNow.AddSeconds(ConfiguraionProvider.AuthenticationCookieDuration)
};
HttpCookie principalCookie = httpContext.Response.Cookies[AuthCookieName];
if (principalCookie == null)
{
principalCookie = new HttpCookie(AuthCookieName);
principalCookie.Value = package.ToXml();
httpContext.Response.AppendCookie(principalCookie);
}
else
{
principalCookie.Value = package.ToXml();
httpContext.Response.SetCookie(principalCookie);
}
}