C# .NET - Single Sign on using ASP.Net (C#.Net)

Hi !

            I need a Sample Application in Single Sign on using ASP.Net (C#.Net) using Cookies or SQL Data Base (or) any other Examples would be better.....

Thanks & Regards

You can impement SSO at coockies and domain level. You will need Forms Authentication Ticket and Cookies to make susccessful SSO like below.

//call SetAuthCookie method to log in. A forms authentication cookie is created.
// Domain name in the cookie defaults to the subdomain where the application resides
FormsAuthentication.SetAuthCookie(txtUserName.Text, false);

//modify the Domain attribute of the cookie to the second level domain
System.Web.HttpCookie MyCookie =
       System.Web.Security.FormsAuthentication.GetAuthCookie(User.Identity.Name.ToString(),
                                                             false);
MyCookie.Domain = “mysite.com”;//the second level domain name
Response.AppendCookie(MyCookie);

In ASP .NET configuration file (web.config) there is an element inside <system.web> element named <machineKey> which Configures keys to use for encryption and decryption of Forms authentication cookie data and view-state data and for verification of out-of-process session state identification. In the web.config of both projects, change the authentication node to this:

<authentication mode="Forms">
<forms name="SampleAuth"
loginUrl="/TestWebApp2/Test.aspx"
slidingExpiration="true">
</forms>
</authentication>

Change the loginUrl to be that of your login page. Then change the
authorization node in the web.config to be this:

<authorization>
<deny users="?" />
</authorization>

In your login page, when you've authenticated the user, do this:

System.Web.Security.FormsAuthentication.RedirectFr omLoginPage("Andy", true);

Now, in your other applications (Webapp2 for example), you can get at the
username ("Andy" in this case), by using:

System.Web.HttpContext.Current.User.Identity.Name

I'd recommend reading up on forms authentication and security.

You can find complete example at http://www.codeproject.com/KB/aspnet/SingleSignon.aspx and http://aspalliance.com/1545_Understanding_Single_SignOn_in_ASPNET_20.all

Also read http://blah.winsmarts.com/2006/05/19/aspnet-20-implementing-single-sign-on-sso-with-membership-api.aspx and http://bytes.com/topic/asp-net/answers/343134-single-sign-transfer-credential-between-webapps

Building your own framework to implement single sign-on is complex. 

An efficient & time-tested way to implement a single sign-on solution is to use Passport authentication or OpenId

For info on implementing Passport Single Sign-in for ASP.NET pages, check this article - http://www.devhood.com/Tutorials/tutorial_details.aspx?tutorial_id=16

Excerpts on OpenId from Wikipedia - http://en.wikipedia.org/wiki/OpenID
OpenID is a shared identity service, which allows Internet users to log on to many different web sites using a single digital identity, single sign-on, eliminating the need for a different user name and password for each site. OpenID is a decentralized, free and open standard that lets users control the amount of personal information they provide.

OpenID is increasingly gaining adoption among large sites, with organizations like AOL, BBC, Google,IBM, Microsoft,MySpace, Orange, VeriSign, Yandex and Yahoo! acting as providers.In addition, OpenID can be used with Windows CardSpace.

To implement OpenID for your ASP.NET website, check these links:
ASP.NET drop-in control to enable OpenID logins for your site - http://blog.nerdbank.net/2007/01/aspnet-drop-in-control-to-enable-openid.html
Integrate OpenId Authentication with ASP.NET Membership, Roles, and Profile - http://www.eggheadcafe.com/tutorials/aspnet/4b3c7c9b-fe80-4e6e-a34e-0e9efed5c575/integrate-openid-authenti.aspx
C# OpenID library - http://code.google.com/p/dotnetopenid/