How to apply SSO (single sign on) - sql

Question

I already have a 5 asp.net application developed under ASP.NET & SQL. each application has his private users tables "credential" to authorize the users on the login.
How can apply a SSO solution to cover the 5 application ? knowing that the same user has different access credential on each application "The username & Password" not same for the same user on the 5 application.
also if there is any third party tool to do that without change any thing on the 5 application, will be very good.
Thanks.

Answer 1

You can use Identity Server for this purpose (here https://identityserver.github.io/Documentation/docsv2/ is documentation for version 3 and you can find there how to run authorization in your APP).
The identity server provide IdentityServerOptions object where you can define some stuff. But for you will be most important Factory property where you can configure Identity Server behavior.
Here is example:
public class Factory
{
public static IdentityServerServiceFactory Create()
{
var factory = new IdentityServerServiceFactory();
// Users are taken from custom UserService which implements IUserService
var userService = new YourUserService();
factory.UserService = new Registration<IUserService>(resolver => userService);
// Custom view service, for custom login views
factory.ViewService = new Registration<IViewService>(typeof(YourViewService));
// Register for Identity Server clients (applications which Identity Server recognize and scopes
factory.UseInMemoryClients(Clients.Get());
factory.UseInMemoryScopes(Scopes.Get());
return factory;
}
}
Where YourUserService will implemtent IUserService (provided by Identity Server) where you can authorize users how you need, in methods AuthenticateLocalAsync and GetProfileDataAsync you can do your own logic for authentication.
And using of the Factory in Startup class for Identity Server project
public void Configuration(IAppBuilder app)
{
var options = new IdentityServerOptions
{
SiteName = "IdentityServer",
SigningCertificate = LoadCertificate(),
EnableWelcomePage = false,
Factory = Factory.Create(),
AuthenticationOptions = new AuthenticationOptions
{
EnablePostSignOutAutoRedirect = true,
EnableSignOutPrompt = false,
},
};
app.UseIdentityServer(options);
}
Here https://github.com/IdentityServer/IdentityServer3.Samples/tree/master/source/CustomUserService you can find some exmaple of this using own UserService
Also here https://github.com/IdentityServer/IdentityServer3.Samples are more examples how to working with Identity Server.
Only bad thing is that in every application you must configure using Identity Server as authentication service so you must change existing apps.