ASP.NET 2.0: Problem in Httpcontext.current.session.add() - asp.net

Can anybody help me to find out solution of following problem.
In ASP.NET website: at Application_OnPostAuthenticate() event, whatever code i write is executed for every request. therefore due to this customidentity object, countryid and weatherid is called everytime for each request (call for database for value). It effect response time of page and unneccessary code execute.
void Application_OnPostAuthenticateRequest(object sender, EventArgs e)
{
// Get a reference to the current User
IPrincipal objIPrincipal = HttpContext.Current.User;
// If we are dealing with an authenticated forms authentication request
if ((objIPrincipal.Identity.IsAuthenticated) && (objIPrincipal.Identity.AuthenticationType == "Forms"))
{
CustomPrincipal objCustomPrincipal = new CustomPrincipal();
objCustomPrincipal = objCustomPrincipal.GetCustomPrincipalObject(objIPrincipal.Identity.Name);
HttpContext.Current.User = objCustomPrincipal;
CustomIdentity ci = (CustomIdentity)objCustomPrincipal.Identity;
HttpContext.Current.Cache["CountryID"] = FatchMasterInfo.GetCountryID(ci.CultureId);
HttpContext.Current.Cache["WeatherLocationID"] = FatchMasterInfo.GetWeatherLocationId(ci.UserId);
Thread.CurrentPrincipal = objCustomPrincipal;
}
}
To solve this problem when i try tochange code as follows
HttpContext.Current.Session.Add("test", FatchMasterInfo.GetWeatherLocationId(ci.UserId);); in place of cache i found foolowing error
"Object refrence not set to the instance of object"
I don't know whether we can store session variable inside Application_OnPostAuthenticate() event or not?

You could try doing this a bit later in the request, such as in the PreRequestHandlerExecute event:
protected void Application_PreRequestHandlerExecute(object sender, EventArgs e)
{
IPrincipal objIPrincipal = HttpContext.Current.User;
if ((objIPrincipal.Identity.IsAuthenticated) && (objIPrincipal.Identity.AuthenticationType == "Forms"))
{
HttpSessionState session = HttpContext.Current.Session;
CustomPrincipal objCustomPrincipal = new CustomPrincipal();
if (session[objIPrincipal.Identity.Name] == null)
{
// get data from database or wherever
objCustomPrincipal = objCustomPrincipal.GetCustomPrincipalObject(objIPrincipal.Identity.Name);
CustomIdentity ci = (CustomIdentity)objCustomPrincipal.Identity;
Object countryID = FatchMasterInfo.GetCountryID(ci.CultureId);
Object weatherLocationID = FatchMasterInfo.GetWeatherLocationId(ci.UserId);
// save in session (not cache as cache is application-wide, not per-user):
session.Add(objIPrincipal.Identity.Name, objCustomPrincipal);
session.Add(objIPrincipal.Identity.Name + "_CountryID", countryID);
session.Add(objIPrincipal.Identity.Name + "_WeatherLocationID", weatherLocationID);
}
else
{
// already have custom principal object in session
objCustomPrincipal = (CustomPrincipal)session[objIPrincipal.Identity.Name];
}
// set the custom principal object to context/thread
HttpContext.Current.User = objCustomPrincipal;
Thread.CurrentPrincipal = objCustomPrincipal;
}
}

You probably don't want to access the session in any event that happens in every request. Some requests don't even have session (for instance, a lot of web service calls, or calls to WebResource.axd that load static resources).

Before adding value to cache object, check if it already exists in the cache.

You might not have session state enabled. Does it work anywhere else (like in a web form's display)?
Look for a <sessionState> element under your system.web element in web.config make sure it's turned on (set it to InProc unless you have a web farm).

Related

Where to create custom IPrincipal object?

I am using Application_PostAuthenticateRequest event in global.asax to create custom IPrincipal object
void Application_PostAuthenticateRequest(object sender, EventArgs args)
{
if (Context.User.Identity.IsAuthenticated == true)
if (Context.User.Identity.AuthenticationType == "Forms")
{
Context.User = new CustomPrincipal(Context.User);
Thread.CurrentPrincipal = Context.User;
}
}
to use in my application where I want get some more information about logged user. I thought it would be called one time when user authenticates but I noticed that it is called on every page request couple times for the same logged user. I found that even requesting image from AppThemes calls this method!
Where should I create that object instead to avoid calling this method multiple times for each user?
I found an answer to my question.
In loggin_in event I should save authentication cookie (I can store all information that I later need in my customPrincipal in UserData property) and in Application_PostAuthenticateRequest I should create CustomPrincipal from that cookie.
That way this event fires every request but I don't hit database - I read data from cookie.
I followed http://www.ondotnet.com/pub/a/dotnet/2004/02/02/effectiveformsauth.html
In my case code is:
void Application_PostAuthenticateRequest(object sender, EventArgs args)
{
HttpCookie authCookie = Context.Request.Cookies[FormsAuthentication.FormsCookieName];
if (authCookie == null)
return;
FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(authCookie.Value);
string[] customData = authTicket.UserData.Split(new Char[] { '|' });
if (Context.User.Identity.IsAuthenticated == true)
{
if (Context.User.Identity.AuthenticationType == "Forms")
{
Context.User = new CustomPrincipal(customData, Context.User);
Thread.CurrentPrincipal = Context.User;
}
}
}
Context.User does not save the new principal across requests; you have to create the custom principal on every request. So it may be best to leave this code here. Otherwise, it will revert to FormsPrincipal or WindowsPrincipal, depending on application authentication mode.
HTH,
Brian

Why HttpContext.Current.Session is null in Global.asax?

I'm using VS2010 and created a simple asp. web forms application, using Development Server to test it.
I try to store user data - queried from sql server - in the session, since I don't want to access database in every request. I'm using the 'Application_AuthenticateRequest' and the 'Session_Start' methods.
First round:
AuthenticateRequest called. The following code ran:
public static void Initialize(string login_name, bool force_refresh)
{
HttpSessionState Session = HttpContext.Current.Session;
object o = Session == null ? null : Session["EMPLOYEE_DATA"];
if (force_refresh || o == null || o.GetType() != typeof(Employee) || (o as Employee).login_name!= login_name)
{
_current = UIManager.GetEmployee(login_name);
if (Session != null)
{
Session["EMPLOYEE_DATA"] = _current;
}
}
else
{
_current = (Employee)o;
}
}
The _current variable is a private static field published through a static property.
In the first round the Session is null, and I think it's ok because the Session_Start not called yet.
The Session_Start looks like this:
protected void Session_Start(object sender, EventArgs e)
{
Session["EMPLOYEE_DATA"] = EmployeeFactory.Current;
}
In the next round the Session_Start is not called of course but in the AuthenticateRequest I can't access to the session. The HttpContext.Current.Session is null and the this.Session reference throw a HttpException says the "Session state is not available in this context".
However I can access the Session from any of the page_load events but it's a bad practice I think that I put authentication every page_load.
Any idea how can I access to the Session?
Thanks for advice,
Péter
You're not able to use Session on the Application_AuthenticateRequest becauase it's not bound at that moment.
I think you're able to use the event Application_AcquireRequestState.
try to use the below code in page_Load
Response.AppendHeader("Refresh", Convert.ToString(Session.Timeout * 15) + ";
URL=SessionExpPage.aspx");

Is there any way to get the requesting user's ID in an ASP.NET web service method?

I know this probably isn't possible, but I would like to be able to get the Request user ID from within an ASP.NET web service method. So far, I've tried User.Identity.Name, Context.Request.LogonUserIdentity.Name, Request.ServerVariables["AUTH_USER"] and Request.ServerVariables["LOGON_USER"]. Am I tilting at windmills here, or is there something super simple that I'm missing?
Well, what do you mean by User ID?
If they've authenticated via Windows Authentication, User.Identity gives you the WindowsIdentity object that corresponds to that user.
If you want the User ID which corresponds to an authenticated user to "magically" show up in your pages, you can do that too! In your Global.asax, there is a function called Application_AuthenticateRequest which you implement to take whatever identity is passed to your application and turn it into a IPrincipal-based object which can be accessed from your pages.
So when you implement AuthenticateRequest(), you can take the HttpContext.Current.User.Identity.Name, and use that to look up your User ID from your database. From there, you construct your own IPrincipal-derived object and set the HttpContext.Currrent.User reference to that object you create. You can then cast "User" in your pages over to the object you create and read the User ID. We do this all the time. Here's some sample code (which actually caches the Principal object so that you don't have to go to the DB on every request):
protected void Application_AuthenticateRequest(object sender, EventArgs e) {
try {
IIdentity myIdentity = HttpContext.Current.User.Identity;
MyPrincipal myPrincipal = (MyPrincipal)HttpContext.Current.Cache[myIdentity.Name];
if (myPrincipal == null) {
myPrincipal = (MyPrincipal)GetPrincipalFromDatabase(HttpContext.Current.User.Identity);
HttpContext.Current.Cache.Insert(myIdentity.Name, myPrincipal, null, DateTime.Now.AddMinutes(1), TimeSpan.Zero);
}
HttpContext.Current.User = myPrincipal;
}
catch (SecurityException) {
HttpContext.Current.User = null;
}
catch (Exception ex) {
Trace.WriteLine("Could not validate your user.");
}
}

ASP.NET - Get SessionID while in from the Global.ASAX

I'm recording the session start times from when people log into my .NET 2.0 web application, but I'd also like to record the Session ID. Can someone give me some example code on how to accomplish this (how to access the Session ID from within the Global.ASAX).
If you need any additional info just let me know.
HttpContext.Current.Session.SessionID
Edit to show null test:
if ((HttpContext.Current != null) && (HttpContext.Current.Session != null) {
id = HttpContext.Current.Session.SessionID
}
You can get at it quite simply with HttpContext.Current.Session.SessionId as you probably already know. You need to be on or after Application_AcquireRequestState before the session state has been loaded, and session state is also only loaded when the requested resource implements IRequiresSessionState. You can see a list of all the events in global.asax here: https://web.archive.org/web/1/http://articles.techrepublic%2ecom%2ecom/5100-10878_11-5771721.html and read more about IRequiresSessionState here: http://msdn.microsoft.com/en-us/library/system.web.sessionstate.irequiressessionstate.aspx
Write to the session the datetime and sessionid at the moment of the first request following ASP.NET's identifying the user's session.
protected void Application_PreRequestHandlerExecute(object sender, EventArgs eventArgs) {
var session = HttpContext.Current.Session;
if (session != null) {
if (session["foo"] == null) {
session["foo"] = DateTime.Now.Ticks + "|" + session.SessionID;
}
}
}

How to set Thread.CurrentPrincipal for use throughout the application?

In an ASP.net application I'm using a Login control with a custom membership provider that I wrote. What I want to do is to set Thread.CurrentPrincipal to my custom Principal object, just after the user is authenticated.
I'm using the setter: Thread.CurrentPrincipal and it sets the Principal object for me but, on all the consequent threads this CurrentPrincipal is overridden with the default one.
Here is my code for the Authenticate event of the Login control:
protected void Login1_Authenticate(object sender, AuthenticateEventArgs e)
{
string username = Login1.UserName;
string password = Login1.Password;
if (Membership.ValidateUser(username, password))
{
var login = sender as Login;
var phoenixIdentity = new PhoenixIdentity("B", "Forms" , true);
var principal = new PhoenixPrincipal(phoenixIdentity);
Thread.CurrentPrincipal = principal;
AppDomain.CurrentDomain.SetThreadPrincipal(principal);
HttpContext.Current.User = principal;
e.Authenticated = true;
}
}
For example, imagine that I login with the username A, everything goes well... Validation passes, but I hardcode the user with the username B in the Identity object which is set to the Principal object I set as the CurrentPrincipal object.
When I check which user is set to the CurrentPrincipal Identity at the end of this method it says it's user B. But when I load another page and then check what the Identity of the CurrentPrincipal is, it says it's user A.
So, how can I make my CurrentPrincipal object to be persistent across all other threads, and where/when does this Login control set the CurrentPrincipal object of the Thread?
Tadas is not wrong, FormsAuthentication correctly implemented will not cause this problem.
Your page is accessible even without login, only in the login page, your thread's principle is set manually by you, but when you hit the other URL, it sure doesnt call your login page and remember each page runs on its own different thread. If you request first page and set thread principle and you request second page in same browser instance, it may or may not be the exact same thread.
This is how FormsAuthentication works,
It checks if Auth Cookie is set or not, it then directs user to login page
Login page must validate and set auth cookie, like FormsAuthentication.SetAuthCookie
Before every page access, Step 1 is executed.
After successful validation of Auth Cookie, ASP.NET internally sets the current user and all differnet parameters according to your membership component.
ASP.NET Global.asax file can give you some events where in you can plugin your code to check just after authentication is successful you can change your current user, remember setting your current principle on login page will not help
We had similar issue when we were using session to store certain important information, after auth sessions were not rebuilt, so we wrote a HTTP Module, and in it's init method, we attached AfterRequestAcquired event and in this event you can write your code to instantiate all your important user related variables.
You can handle FormsAuthentication_OnAuthenticate(object sender, FormsAuthenticationEventArgs e) (in Global.asax) and set CurrentPrincipal here.
void FormsAuthentication_OnAuthenticate(object sender, FormsAuthenticationEventArgs e)
{
var phoenixIdentity = new PhoenixIdentity("B", "Forms" , true);
var principal = new PhoenixPrincipal(phoenixIdentity);
e.User = principal;
}
This is what I did in FormsAuthentication_OnAuthenticate method:
if (FormsAuthentication.CookiesSupported)
{
if (Request.Cookies[FormsAuthentication.FormsCookieName] != null)
{
try
{
FormsAuthenticationTicket ticket =
FormsAuthentication.Decrypt(Request.Cookies[FormsAuthentication.FormsCookieName].Value);
var myIdentity = new GenericIdentity("B");
var principal = new GenericPrincipal(myIdentity, new string[]{"rola1"});
e.User = principal;
}
catch (Exception ex)
{
// Decrypt method failed.
}
}
}
else
{
throw new HttpException("Cookieless Forms Authentication is not " +
"supported for this application.");
}
it seems that it's working what it should do... It's just that if I put my custom principal/identity pair as e.User, then I have serialization problem which I need to fix next... Thank you guys...

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