sync cookies and sessions in different subdomains (asp.net) - asp.net

I am building a site in asp.net and have multiple subdomains. For example,
one.cookies.com
two.cookies.com
I want my users to be able to login at either subdomain and be logged in for both websites. In addition, I'd like the sessions and cookies to be in sync. So far I haven't found a reliable way to do this.

If you want to sync the ASP.NET session and you aren't using forms authentication (for example, your site has no login), try adding the following code to your Globals.asax file. This worked like a champ for me and saved me some serious grief.
protected void Application_PreRequestHandlerExecute(Object sender, EventArgs e)
{
/// only apply session cookie persistence to requests requiring session information
#region session cookie
if (Context.Handler is IRequiresSessionState || Context.Handler is IReadOnlySessionState )
{
/// Ensure ASP.NET Session Cookies are accessible throughout the subdomains.
if (Request.Cookies["ASP.NET_SessionId"] != null && Session != null && Session.SessionID != null)
{
Response.Cookies["ASP.NET_SessionId"].Value = Session.SessionID;
Response.Cookies["ASP.NET_SessionId"].Domain = ".know24.net"; // the full stop prefix denotes all sub domains
Response.Cookies["ASP.NET_SessionId"].Path = "/"; //default session cookie path root
}
}
#endregion
}
I found this originally posted here:
http://www.know24.net/blog/ASPNET+Session+State+Cookies+And+Subdomains.aspx

When you create the cookie you can set the domain:
HttpCookie cookie = new HttpCookie("name", "value");
cookie.Domain = "cookies.com";
This will allow your cookie to be accessible from all subdomains of cookies.com.
If you are using FormsAuthentication then you can set the domain for the auth cookie in web.config:
<forms name=".ASPXAUTH"
loginUrl="login.aspx"
defaultUrl="default.aspx"
protection="All"
timeout="30"
path="/"
requireSSL="false"
domain="cookies.com">
</forms>
Remember that for the single sign-on to work on multiple subdomains your ASP.NET applications must share the same machine keys as explained in this CodeProject article.
Sharing sessions between different subdomains (different worker processes) is more difficult because sessions are constrained to an application and you will have to implement a custom session synchronization mechanism.

Yes, you need to use ".cookies.com" not "cookies.com"

I beleive make the cookie for http://cookies.com. (No subdomain or www listed)

Related

session variables timeout in asp.net app

In my web app I'm using some session variables, which are set when I login:
e.g. Session("user_id") = reader("user_id")
I use this through my app.
When the session variable times out, this throws errors mainly when connecting to the database as session("user_id") is required for some queries.
How can I set my session variables so that once they are timed out to go to the login page or how can at least increase the length of time the are available?
I'm guessing you're using Forms Authentication. The trick here is to ensure that your Forms Authentication expires before the session does.
I wrote about this in this answer here:
How to redirect to LogIn page when Session is expired (ASP.NET 3.5 FormsAuthen)
For example:
Configure your Forms Authentication - this sets the timeout to 60 minutes:
<authentication mode="Forms">
<forms defaultUrl="~/Default.aspx"
loginUrl="~/Login.aspx"
slidingExpiration="true"
timeout="60" />
</authentication>
Extend Session expiry to a longer time:
<sessionState
mode="InProc"
cookieless="false"
timeout="70"/>
In your Login.aspx code behind you could also do a Session.Clear(); to remove stale session data before assigning session values.
In the past I've used a base page or master page on every page (making an exception for the login page) that reads a session token to see if a user is logged in currently.
If it ever reads a null it saves the current url and redirects to the login page.
After logging in it reads the saved url and redirects the user back to the requested page.
Increasing the session timeout value is a setting in IIS.
How can I set my session variables so that once they are timed out to go to the login page
Check if they are = null do a Response.Redirect("Home.aspx");
or how can at least increase the
length of time the are available?
Its in the web.config within the sessionState element
I think a lot of people wrap their session calls to provide a "lazy load" pattern. Something like this:
class SessionHelper
{
public static string GetUserId()
{
string userId = (string)System.Web.HttpContext.Current.Session["UserId"];
if( userId == null )
{
userId = reader("UserId");
System.Web.HttpContext.Current.Session["UserId"] = userId;
}
return userId;
}
}

ASP.NET: How to Detect Authentication Timeout

I've seen multiple articles like this one that explain how to detect that a user's session has timed out. And for clarity's sake, these articles are referring to the timeout value defined by this web.config line:
<sessionState mode="InProc" cookieless="UseDeviceProfile" timeout="120" />
Not to get into that method too much, but this involves checking that Session.IsNewSession is true and that a session cookie already exists. But I haven't seen any articles on how to detect authentication timeout -- the one defined by this web.config line:
<authentication mode="Forms">
<forms loginUrl="~/Home/Customer" timeout="60" name=".ASPXAUTH" requireSSL="false" slidingExpiration="true" defaultUrl="~/Home/Index" cookieless="UseDeviceProfile" enableCrossAppRedirects="false"/>
</authentication>
Multiple articles online, including this SO post, have said that your Session timeout value should generally be double your Authentication timeout value. So right now, as above, my Session is 120 and my Authentication is 60. This means that I'll never get in a situation where the Session has timed out, but the user is still Authenticated; if the user ever times out, it will be due to Authentication, not Session.
So, like everyone else, I'm interested in how to report to the user that their session has timed out (but really it'll be due to the Authentication timeout). Does anyone know of a way to accomplish this, or any resources online that can point me to a solution?
This is probably not the optimum approach, but here's something I thought of.
On login, record a timestamp in the session marking when the user logged in. On each subsequent request (maybe in the global.asax BeginRequest?), compare this timestamp to the current time, and match this up with the authentication timeout (Scott Hanselman explains how to read it here).
That's my "off top of my head" thought anyhow...
I would leverage the http pipeline early in the request and send an apporpriate response.
My source for answering such questions is:
Professional ASP.NET 2.0 Security, Membership, and Role Management
An HTTP module might do the trick:
Web.config:
<configuration>
<system.web>
<httpModules>
<add name="MyAuthModule" type="MyAssembly.Security.MyAuthModule, MyAssembly"/>
...
The Actual HTTP Module:
/// <summary>
/// A module for detecting invalid authentication
/// </summary>
/// <remarks>See "How To Implement IPrincipal" in MSDN</remarks>
public class MyAuthModule : IHttpModule
{
#region IHttpModule Members
void IHttpModule.Dispose() { }
void IHttpModule.Init(HttpApplication context)
{
context.AuthenticateRequest += new EventHandler(context_AuthenticateRequest);
}
#endregion
/// <summary>
/// Inspect the auth request...
/// </summary>
/// <remarks>See "How To Implement IPrincipal" in MSDN</remarks>
private void context_AuthenticateRequest(object sender, EventArgs e)
{
HttpApplication a = (HttpApplication)sender;
HttpContext context = a.Context;
// Extract the forms authentication cookie
string cookieName = FormsAuthentication.FormsCookieName;
HttpCookie authCookie = context.Request.Cookies[cookieName];
if (authCookie != null)
{
FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(authCookie.Value);
// check if previously authenticated session is now dead
if (authTicket != null && authTicket.expired)
{
// send them a Response indicating that they've expired.
}
}
}
}
Good luck!
When you log the user, you could drop a cookie on the user's machine indicating that they had a session. When the user reaches the login page (because if their session expired, their login must also have), check to see if the user has that cookie and if they have any of the session keys you expect them to have (if this proves difficult, just set a session variable when they log in). if they have the cookie, but none of the session keys, then their session expired.

Single Sign-on SignOut problem : FormsAuthentication.SignOut() is not working

I used the Single Sign-on demo from: http://www.codeproject.com/KB/aspnet/SingleSignon.aspx
And I add a SignOut function for this demo, but found a problem:
when I set the cookie.Domain, FormsAuthentication.SignOut() is not working and the cookie can not be cleared.
If the cookie has not been set the cookie.Domain, FormsAuthentication.SignOut() works.
I used C# asp.net.
And could anybody tell me some simple and practical Single Sign-On and Single Sign-Off solutions using asp.net ?
In case you are using the authentication for the same domain and subdomain, try adding the domain name in the web.config instead of adding the domain through code. you will no have to code anything if you use this web.config entry
<authentication mode="Forms">
<forms loginUrl="~/Account/LogOn" timeout="2880" domain="abc.com"/>
</authentication>
This entry tells the asp.net engine that the authentication cookie will be used for all subdomains of abc.com . Try using this and see if it works.
This worked for me:
In the Logout event/ method of each site, use Cookies collection in Request object & delete the relevant cookies as below:
enter code hereHttpCookie cookie = Request.Cookies.Get(".CommonCookieName");
cookie.Expires = DateTime.Now.AddDays(-1);
HttpContext.Current.Response.Cookies.Add(cookie);
If all the sites in SSO use same cookie, then this is simple as described above.
If few or each site participating in SSO use their own cookie/ user name for same subject (person), then u need to remove all the cookies. (perhaps establish a central location with just the mapping of the usernames & cookie names in each site in SSO collection of sites.
This works for me
public virtual ActionResult LogOff()
{
FormsAuthentication.SignOut();
foreach (var cookie in Request.Cookies.AllKeys)
{
Request.Cookies.Remove(cookie);
}
foreach (var cookie in Response.Cookies.AllKeys)
{
Response.Cookies.Remove(cookie);
}
return RedirectToAction(MVC.Home.Index());
}

ASP.NET: Authenticating user in code

I'm playing around with authentication and authorization to prepare for some task. I've created two pages: Login.aspx and Default.aspx. In config file i've set authentication to forms and denied unauthenticated users access:
<authentication mode="Forms">
<forms name="aaa" defaultUrl="~/Login.aspx" />
</authentication>
<authorization>
<deny users="?"/>
</authorization>
Then I've written some simple code to authenticate my user in Login.aspx:
protected void Page_Load(object sender, EventArgs e)
{
GenericIdentity identity = new GenericIdentity("aga", "bbb");
Context.User = new GenericPrincipal(identity, new String[] { "User" }); ;
Response.Redirect("~/Default.aspx");
}
When i run it, the redirection doesn't take place. Instead Login.aspx is called over and over because the user is not authenticated (Context.User.Identity.IsAuthenticated is false at every load). What am i doing wrong?
Context.User only sets the principal for the current request. Once the redirect takes place, the current request ends and a new one begins with the non-overridden principal again (which is apparently not authenticated). So, setting Context.User doesn't actually authenticate anything.
Using FormsAuthentication.SetAuthCookie() will set the user's cookie to a valid value accepted by the FormsAuthentication provider, or put the token in the URL. You can redirect to your heart's content because the cookie obviously sticks with the user for future requests.
From MSDN (em added):
With forms authentication, you can use the SetAuthCookie method when you want to authenticate a user but still retain control of the navigation with redirects.
As stated, this does not necessarily require cookies - the name is a little misleading, because it will still work via the URL if FormsAuthentication is in cookieless mode:
The SetAuthCookie method adds a forms-authentication ticket to either the cookies collection, or to the URL if CookiesSupported is false.
Use FormsAuthentication.SetAuthCookie(..). Or FormsAuthentication.RedirectFromLoginPage(..).
You need to actually set the user as authenticated. All of the following methods will work and let you actually get away from your login screen.
FormsAuthentication.Authenticate()
FormsAuthentication.RedirectFromLoginPage()
FormsAuthentication.SetAuthCookie()
Lots of ways to get to the same result.
You need to actually make a call to the formsAuthentication provider to set the login.
FormsAuthentication.RedirectFromLoginPage(txtUser.Text, chkPersistLogin.Checked)
is a simple example
After creating the dummy Context.User, you need to perform a FormsAuthentication.SetAuthCookie or RedirectFromLoginPage method.

How do I logout of multiple asp.net applications?

I have a main asp.net app, which is written in asp.net 1.1. Runnning underneath the application are several 2.0 apps. To completely logout a user can I just logout of the 1.1 app with FormsAuthentication.SignOut or is it more complicated than that?
What you are looking to do is called Single Sign On and Single Sign Off. There are differences based on how you have the applications set up. I will try to clarify where those differences come into play.
To implement single sign on and single sign off you need to make the cookie name, protection, and path attributes the same between all the applications.
<authentication mode="Forms">
<forms name=".cookiename"
loginUrl="~/Login.aspx"
timeout="30"
path="/" />
</authentication>
Next you need to add the machine keys and they need to be the same between all your applications.
<machineKey validationKey="F9D1A2D3E1D3E2F7B3D9F90FF3965ABDAC304902"
encryptionKey="F9D1A2D3E1D3E2F7B3D9F90FF3965ABDAC304902F8D923AC"
validation="SHA1" />
Are you using second or third level domains for the applications? If so you will need to do a little bit more by adding the domain to the cookie:
protected void Login(string userName, string password)
{
System.Web.HttpCookie cookie = FormsAuthentication.GetAuthCookie(userName, False);
cookie.Domain = "domain1.com";
cookie.Expires = DateTime.Now.AddDays(30);
Response.AppendCookie(cookie);
}
Now to do single sign off, calling FormsAuthentication.SignOut may not be enough. The next best thing is to set the cookie expiration to a past date. This will ensure that the cookie will not be used again for authentication.
protected void Logout(string userName)
{
System.Web.HttpCookie cookie = FormsAuthentication.GetAuthCookie(userName, False);
cookie.Domain = "domain1.com";
cookie.Expires = DateTime.Now.AddDays(-1);
Response.AppendCookie(cookie);
}
I am taking into consideration you are using the same database for all the applications. If the applications use a separate database for registration and authentication, then we will need to do some more. Just let me know if this is the case. Otherwise this should work for you.
It could be easier if you are having a central session store for all your applications. You can then set the session to null in one place.
This worked for me:
In the Logout event, instead of FormsAuthentication.GetAuthCookie method use Cookies collection in Request object as below:
HttpCookie cookie = Request.Cookies.Get(otherSiteCookieName);
cookie.Expires = DateTime.Now.AddDays(-1);
HttpContext.Current.Response.Cookies.Add(cookie);
Ofcourse, this requires u know the Cookie name of the site(s) you want the user to be logged out - which however won't be a problem if you are using the same cookie across all the web apps.
I prefer to use web.config
<authentication mode="Forms">
<forms domain=".tv.loc" loginUrl="~/signin" timeout="2880" name="auth" />
</authentication>

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