Asp.net identity regenerate new session id

In ASP.NET Identity, the session ID is generated by the System.Web.Security.FormsAuthentication class. By default, the session ID is generated randomly and is unique for each user.

If you want to regenerate a new session ID for a user, you can use the FormsAuthentication.SignOut() method, which will invalidate the current session and generate a new one.

Here's an example:

using Microsoft.AspNet.Identity;
using System.Web.Security;

// Get the user manager
var userManager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext()));

// Get the user
var user = userManager.FindById(userId);

// Sign out the user
FormsAuthentication.SignOut();

// Regenerate the session ID
FormsAuthentication.SetAuthCookie(userManager.GetUserId(user), false);

In this example, we first get the user manager and the user using the FindById method. Then, we sign out the user using FormsAuthentication.SignOut(), which will invalidate the current session. Finally, we regenerate the session ID using FormsAuthentication.SetAuthCookie with the new user ID and false as the second parameter, which indicates that the cookie should be set without a password.

Note that regenerating the session ID will also invalidate any existing authentication tickets, so you may need to re-authenticate the user after regenerating the session ID.

Alternatively, you can use the Microsoft.Owin.Security.Cookies.CookieAuthenticationOptions class to regenerate the session ID. Here's an example:

using Microsoft.Owin.Security.Cookies;
using Microsoft.Owin.Security;

// Get the cookie authentication options
var options = new CookieAuthenticationOptions();

// Regenerate the session ID
options.AuthenticationType = "Cookies";
options.TicketDataFormat = new TicketDataFormat(new Sha256TicketDataFormat());
options.SessionStore = new SessionStore();

// Set the new session ID
options.SessionId = Guid.NewGuid().ToString();

In this example, we create a new instance of the CookieAuthenticationOptions class and set the AuthenticationType property to "Cookies". We then set the TicketDataFormat property to a new instance of the Sha256TicketDataFormat class, which will generate a new session ID. Finally, we set the SessionStore property to a new instance of the SessionStore class, which will store the new session ID.

Note that regenerating the session ID using this method will also invalidate any existing authentication tickets, so you may need to re-authenticate the user after regenerating the session ID.