How to get recently authenticated user?

I am working with MVC 3 and I have just implemented a wrapper for the FormsAuthenticationService.

Something similar to the following.

public void SignIn(string username, bool createPersistantCookie)
{
    if (string.IsNullOrEmpty(username)) 
        throw new ArgumentException("Value Cannot be null or empty", "username");

    For开发者_开发百科msAuthentication.SetAuthCookie(username, createPersistantCookie);
}

Reluctantly, I have gotten this to work, but now I am not quite sure how to get the information that I have stored.

Once the user is in my system, how can I now safely retrieve this information if I need to grab their UserID out of the database?

Based on the additional information provided, you want to store additional data with the FormsAuthentication ticket. To do so, you need first create a custom FormsAuthentication ticket:

Storing Data

Grab the current HttpContext (not worrying about testability)

var httpContext = HttpContext.Current;

Determine when the ticket should expire:

var expires = isPersistent 
                ? DateTime.Now.Add(FormsAuthentication.Timeout) 
                : NoPersistenceExpiryDate; // NoPersistenceExpiryDate = DateTime.MinValue

Create a new FormsAuthentication ticket to hold your custom data.

var authenticationTicket = new FormsAuthenticationTicket(
                             1, 
                             username, 
                             DateTime.Now, 
                             DateTime.Now.Add(FormsAuthentication.Timeout), 
                             isPersistent, 
                             "My Custom Data String"); //Limit to about 1200 bytes max

Create your HTTP cookie

new HttpCookie(FormsAuthentication.FormsCookieName, FormsAuthentication.Encrypt(authenticationTicket))
  {
    Path = FormsAuthentication.FormsCookiePath,
    Domain = FormsAuthentication.CookieDomain,
    Secure = FormsAuthentication.RequireSSL,
    Expires = expires,
    HttpOnly = true
  };

And finally add to the response

httpContext.Response.Cookies.Add(cookie);

Retrieving Data

Then you can retrieve your data on subsequent requests by parsing the stored authentication ticket...

Again, grab current HttpContext

var httpContext = HttpContext.Current

Check to see if the request has been authenticated (call in Application_AuthenticateRequest or OnAuthorize)

if (!httpContext.Request.IsAuthenticated)
    return false;

Check to see if you have a FormsAuthentication ticket available and that it has not expired:

var formsCookie = httpContext.Request.Cookies[FormsAuthentication.FormsCookieName];
if (formsCookie == null)
  return false;

Retrieve the FormsAuthentication ticket:

var authenticationTicket = FormsAuthentication.Decrypt(formsCookie.Value);
if (authenticationTicket.Expired)
  return false;

And finally retrieve your data:

var data = authenticationTicket.UserData;

You haven't actually stored a user id in the database. All the code that you've written does is store an authentication cookie on the users computer, either as a session cookie (not persistent) or as a persistent one.

When your page refreshes, it will get the cookie automatically, decode it, and populate the IPrincipal object which you access from the User.Current property of your controller.