/// <summary>
/// Get the Key/IV secret from the cookies and generate the parts that don't yet exist
/// and directly save it to the cookies collection
/// </summary>
/// <returns></returns>
internal static Crypt.Secret GetSecret <M>(this IStorageControl <M> controlStorage)
where M : class, new()
{
Crypt.Secret secret;
string keyString;
var cookie = controlStorage.Request.Cookies[controlStorage.StorageID()];
if (cookie != null)
{
keyString = cookie["key"];
if (keyString != null)
{
var key = Convert.FromBase64String(keyString);
secret = Crypt.NewSecret(key);
}
else
{
secret = Crypt.NewSecret();
}
}
else
{
secret = Crypt.NewSecret();
}
controlStorage.Response.Cookies[controlStorage.StorageID()]["key"] = Convert.ToBase64String(secret.Key);
return(secret);
}
/// <summary>
/// To be called in Page_Load():
/// Load the M object from the storage, propagate it to all sub-controls
/// and recursively hide them all below the main control.
/// Also sets a global reference to the main control in IIE for testing.
/// </summary>
/// <typeparam name="M"></typeparam>
/// <param name="controlStorage"></param>
public static void LoadMain <M>(this IStorageControl <M> controlStorage)
where M : class, new()
{
controlStorage.ClearIfRequested();
Guid sessionOverride;
if (!controlStorage.IsPostBack && Guid.TryParse(controlStorage.Request.QueryString["session"], out sessionOverride))
{
controlStorage.Main = Main.LoadMain <M>(sessionOverride);
}
else
{
switch (controlStorage.GetStorage())
{
case Storage.ViewState:
controlStorage.Main = (M)controlStorage.ViewState[controlStorage.StorageID()];
break;
case Storage.Session:
controlStorage.Main = (M)controlStorage.Session[controlStorage.StorageID()];
break;
case Storage.Database:
var cookie = controlStorage.Request.Cookies[controlStorage.StorageID()];
if (cookie != null)
{
Guid session;
if (Guid.TryParse(cookie["session"], out session))
{
Func <byte[], byte[]> filter = null;
if (controlStorage.GetEncryptDatabaseStorage())
{
filter = x => Crypt.Decrypt(controlStorage.GetSecret(), x); // closure
}
controlStorage.Main = Main.LoadMain <M>(session, filter);
}
}
break;
}
}
if (controlStorage.Main == null)
{
controlStorage.Main = new M();
}
CurrentMain = controlStorage.Main;
ControlRootExtension.SetRoot(controlStorage);
controlStorage.PropagateMain(controlStorage.Main);
}
/// <summary>
/// To be called at the end of OnPreRender():
/// Persist the in this page life-cycle stage immutable Main object.
/// </summary>
/// <typeparam name="M"></typeparam>
/// <param name="controlStorage"></param>
public static void SaveMain <M>(this IStorageControl <M> controlStorage)
where M : class, new()
{
var storage = controlStorage.GetStorage();
Trace.Assert(controlStorage.Main != null, "SaveMain() without preceding LoadMain()");
switch (storage)
{
case Storage.ViewState:
controlStorage.ViewState[controlStorage.StorageID()] = controlStorage.Main;
break;
case Storage.Session:
controlStorage.Session[controlStorage.StorageID()] = controlStorage.Main;
break;
case Storage.Database:
Guid session = Guid.NewGuid(); // cannot exist in the database -> will get a new one on SaveMain()
var cookie = controlStorage.Request.Cookies[controlStorage.StorageID()];
if (cookie != null)
{
Guid.TryParse(controlStorage.Request.Cookies[controlStorage.StorageID()]["session"], out session);
}
Func <byte[], byte[]> filter = null;
if (controlStorage.GetEncryptDatabaseStorage())
{
filter = x => Crypt.Encrypt(controlStorage.GetSecret(), x); // closure
}
session = Main.SaveMain(controlStorage.Main, session, filter);
var configDays = ConfigurationManager.AppSettings["DatabaseStorageExpires"];
var days = String.IsNullOrWhiteSpace(configDays) ? 1 : int.Parse(configDays);
controlStorage.Response.Cookies[controlStorage.StorageID()]["session"] = session.ToString();
controlStorage.Response.Cookies[controlStorage.StorageID()].Expires = DateTime.Now.AddDays(days);
break;
}
}
/// <summary>
/// Hook to clear the storage for that control with ?clear=true
/// ViewState is reset anyway on GET requests, therefore NOP in that casefa
/// GET-arguments:
/// clear=[true|false] triggers clearing the storage
/// endresponse=[true|false] whether the page at the given URL
/// storage=[Session|Database] clears the selected storage type regardless of config
/// </summary>
/// <typeparam name="M"></typeparam>
/// <param name="controlStorage"></param>
/// <returns></returns>
internal static void ClearIfRequested <M>(this IStorageControl <M> controlStorage)
where M : new()
{
if (!controlStorage.IsPostBack)
{
bool clear = false;
bool.TryParse(controlStorage.Request.QueryString["clear"], out clear);
if (clear)
{
Storage storage;
Enum.TryParse <Storage>(controlStorage.Request.QueryString["storage"], true, out storage);
if (storage == Storage.ViewState) // no meaningful override given
{
storage = controlStorage.GetStorage();
}
bool endresponse = false;
bool.TryParse(controlStorage.Request.QueryString["endresponse"], out endresponse);
switch (storage)
{
case Storage.ViewState:
break;
case Storage.Session:
controlStorage.Session.Remove(controlStorage.StorageID());
break;
case Storage.Database:
// delete from the database and expire the cookie
var cookie = controlStorage.Request.Cookies[controlStorage.StorageID()];
if (cookie != null)
{
Guid session;
Guid.TryParse(controlStorage.Request.Cookies[controlStorage.StorageID()]["session"], out session);
using (var db = new ASP_DBEntities())
{
var sql = @"
DELETE FROM Main
WHERE session = @session
";
var param = new SqlParameter("session", session);
db.Database.ExecuteSqlCommand(sql, param);
}
controlStorage.Request.Cookies[controlStorage.StorageID()].Expires = DateTime.Now.AddDays(-1);
}
break;
default:
throw new NotImplementedException(String.Format(
"Storage {0}", storage));
}
if (endresponse)
{
controlStorage.Response.Clear();
controlStorage.Response.End();
}
}
}
}