Setting up authentication

Once you integrate Kentico membership into your MVC project, you can implement actions that allow visitors to sign in and out of the website with Kentico user accounts.

Use the following approach to develop sign-in actions:

1. Create a new controller class in your MVC project or edit an existing one.

2. Prepare a property that gets an instance of the Kentico.Membership.SignInManager class for the current request – call HttpContext.GetOwinContext().Get<SignInManager>().

3. Implement two sign-in actions – one basic GET action to display the sign-in form and a second POST action to handle the authentication when the form is submitted.

4. Call the PasswordSignInAsync method of the SignInManager instance to authenticate users against the Kentico database (within the code of the POST action).

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    using System;
    using System.Web;
    using System.Web.Mvc;
    using System.Threading.Tasks;
   
    using Microsoft.AspNet.Identity;
    using Microsoft.AspNet.Identity.Owin;
    using Microsoft.Owin.Security;
   
    using Kentico.Membership;
   
    using CMS.EventLog;
    using CMS.SiteProvider;
   
   
   
    

   Sign-in actions example

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            /// <summary>
            /// Provides access to the Kentico.Membership.SignInManager instance.
            /// </summary>
            public SignInManager SignInManager
            {
                get
                {
                    return HttpContext.GetOwinContext().Get<SignInManager>();
                }
            }
   
            /// <summary>
            /// Basic action that displays the sign-in form.
            /// </summary>
            public ActionResult SignIn()
            {
                return View();
            }        
   
            /// <summary>
            /// Handles authentication when the sign-in form is submitted. Accepts parameters posted from the sign-in form via the SignInViewModel.
            /// </summary>
            [HttpPost]
            [ValidateAntiForgeryToken]
            [ValidateInput(false)]
            public async Task<ActionResult> SignIn(SignInViewModel model, string returnUrl)
            {
                // Validates the received user credentials based on the view model
                if (!ModelState.IsValid)
                {
                    // Displays the sign-in form if the user credentials are invalid
                    return View();
                }
   
                // Attempts to authenticate the user against the Kentico database
                SignInStatus signInResult = SignInStatus.Failure;
                try
                {
                    signInResult = await SignInManager.PasswordSignInAsync(model.UserName, model.Password, model.SignInIsPersistent, false);
                }
                catch (Exception ex)
                {
                    // Logs an error into the Kentico event log if the authentication fails
                    EventLogProvider.LogException("MvcApplication", "SignIn", ex);
                }
   
                // If the authentication was not successful, displays the sign-in form with an "Authentication failed" message 
                if (signInResult != SignInStatus.Success)
                {
                    ModelState.AddModelError(String.Empty, "Authentication failed");
                    return View();
                }
   
                // If the authentication was successful, redirects to the return URL when possible or to a different default action
                string decodedReturnUrl = Server.UrlDecode(returnUrl);
                if (!string.IsNullOrEmpty(decodedReturnUrl) && Url.IsLocalUrl(decodedReturnUrl))
                {
                    return Redirect(decodedReturnUrl);
                }
                return RedirectToAction("Index", "Home");
            }
   
   
   
    

5. We recommend creating a view model for your sign-in action (SignInViewModel in the example above). The view model allows you to:

   • Pass parameters from the sign-in form (username, password, and sign-in persistence status).
   • Use data annotations to define validation and formatting rules for the sign-in parameters. See System.ComponentModel.DataAnnotations for more information about the available data annotation attributes.

To allow users to sign out on your website, extend your sign-in controller class:

1. Prepare a property that provides access to the authentication middleware functionality (Microsoft.Owin.Security.IAuthenticationManager instance) – use the HttpContext.GetOwinContext().Authentication property.

2. Add another action to handle sign-out requests.

3. Call the SignOut(DefaultAuthenticationTypes.ApplicationCookie) method of the authentication manager to sign out the current user.

   Sign-out action example

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            /// <summary>
            /// Provides access to the Microsoft.Owin.Security.IAuthenticationManager instance.
            /// </summary>
            public IAuthenticationManager AuthenticationManager
            {
                get
                {
                    return HttpContext.GetOwinContext().Authentication;
                }
            }
   
            /// <summary>
            /// Action for signing out users. The Authorize attribute allows the action only for users who are already signed in.
            /// </summary>
            [Authorize]
            [HttpPost]
            [ValidateAntiForgeryToken]
            public ActionResult SignOut()
            {
                // Signs out the current user
                AuthenticationManager.SignOut(DefaultAuthenticationTypes.ApplicationCookie);
   
                // Redirects to a different action after the sign-out
                return RedirectToAction("Index", "Home");
            }
   
   
   
    

Finally, you need to design a user interface for the authentication logic:

• Create a view for the SignIn action and display an appropriate sign-in form for your website. We recommend using a strongly typed view based on your sign-in view model.
• Add a sign in button or link that targets the SignIn action (for example within your site’s main layout page).
• Add a sign out button or link that targets the SignOut action.

Visitors can now sign in to your site with Kentico user accounts from the connected database. If you wish to allow users to register new accounts, see Enabling user registration.