ASP.NET Identity Tutorial

In our last post Introduction to ASP.NET Ide ntity, We had discussed features it supports. In the next few series of article on ASP.NET Identity Tutorial, we will explain to you how to build a simple login/logout and user registration page using the ASP.NET Identity Framework using Microsoft.OWIN Middleware

Here is the link to all the tutorials

Introduction to ASP.NET Identity
ASP.NET Identity Tutorial – Getting Started
ASP.NET Identity Tutorial – OWIN Authentication Middleware
ASP.NET Core Identity

Prepare the Project

First, let us create a Project in Visual Studio. We are Using Visual Studio 2015, and the latest .NET Framework 4.6.1.

Open Visual Studio 2015 and click on New Project. Select .NET Framework 4.6.1 and ASP.NET Web Application (.NET Framework). Enter the Project name as ASPNetIdentity and then Click OK

In the New ASP.NET Web Application dialogue box, choose Empty Template and select MVC. Choose No Authentication and click ok

Components of ASP.NET Identity

There are three main Components in the ASP.NET Identity

Microsoft.AspNet.Identity.Core
Microsoft.AspNet.Identity.EntityFramework
Microsoft.AspNet.Identity.Owin

Microsoft.AspNet.Identity.Core

This is the Core module of the Identity System. It contains classes and interfaces related to managing users and roles for ASP.NET Identity.

Microsoft.AspNet.Identity.EntityFramework

This is an Entity Framework namespace specific to ASP.NET Identity. This has a concrete Implementation of the Interfaces defined in the Microsoft.ASPNet.Identity.Core namespace, which will persist the ASP.NET Identity data and schema to SQL Server.

Microsoft.AspNet.Identity.Owin

This package contains functionality that is used to plug in OWIN authentication with ASP.NET Identity in ASP.NET applications. The Identity System uses the Owin middleware components for Cookie Authentication and provides methods to implement external logins such as Facebook, Google and Twitter.

Installing the Components

Open the NuGet Package manager Console and install the components using the command shown below.

Install-Package Microsoft.AspNet.Identity.Core

Install-Package Microsoft.AspNet.Identity.EntityFramework

Install-Package Microsoft.aspnet.identity.owin

The above command will install the latest version of the components. The Latest Version at the time of writing this article is 2.2.1

The following additional dependencies are also get installed

EntityFramework 6.1.0, Newtonsoft.Json 4.5.11, Owin 1.0.0, Microsoft.Owin 2.1.0, Microsoft.Owin.Security 2.1.0, Microsoft.Owin.Security.Cookies 2.1.0 & Microsoft.Owin.Security.OAuth 2.1.0

Preparing the Database

The ASP.NET Identity uses Entity framework to connect to the database and store the user’s information. To do that, we need to create a database. Let us use the localdb to do that.

Open the web.config and add the following connection string under configuration section.

<add name="DefaultConnection" connectionString="Data Source=(LocalDb)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\ASPNetIdentity.mdf;Initial Catalog=ASPNetIdentity;Integrated Security=True"

providerName="System.Data.SqlClient" />

</connectionStrings>

Feel free to change the Connection string as per your chosen database

IdentityUser

We need a class to represent the user, where all the user-related information’s are kept. This model class must implement the interface IUser<TKey>.

This Interface is defined in the Microsoft.AspNet.Identity namespace. It requires an ID and Name field for every user.

ID Property is a string field. The system generates a GUID and stores it as a string in this field. You can override this field with an integer or any other type

The IdentityUser is the Entity Framework implementation of the IUser<Tkey> Interface. It is in the Microsoft.AspNet.Identity.EntityFramework namespace. IdentityUser class extends the IUser interface by adding the minimum required fields for our user model.

A peek into IdentityUser class shows us the following properties

public virtual string Email { get; set; }

public virtual bool EmailConfirmed { get; set; }

public virtual TKey Id { get; set; }

public virtual bool LockoutEnabled { get; set; }

public virtual DateTime? LockoutEndDateUtc { get; set; }

public virtual ICollection<TLogin> Logins { get; }

public virtual string PasswordHash { get; set; }

public virtual string PhoneNumber { get; set; }

public virtual bool PhoneNumberConfirmed { get; set; }

public virtual ICollection<TRole> Roles { get; }

public virtual string SecurityStamp { get; set; }

public virtual bool TwoFactorEnabled { get; set; }

public virtual string UserName { get; set; }

Most of these fields are self-explanatory. We can use the IdentiyUser in our Application directly. But it is advisable to define our own class and inherit it from IdentityUser. You can add your custom fields to this class.

public class ApplicationUser :IdentityUser

{

//You can extend this class by adding additional fields like Birthday

}

Copy the above code to the IdentityModels.cs under models folder

You need to import the following namespaces

using Microsoft.AspNet.Identity;

using Microsoft.AspNet.Identity.EntityFramework;

Database Context

The Entity Framework requires DbContext, which is responsible for interacting with the entity model and the database.

Microsoft.AspNet.Identity.EntityFramework namespace implements the IdentityDbContext<TUser> which inherits from DbContext. This class provides the ready DbSets for Users and Roles.

All we need to do is inherit from the IdentityDbContext<TUser>. Here TUser is our ApplicationUser. In the constructor of the class pass the connection string to our database.

public class ApplicationDbContext : IdentityDbContext<ApplicationUser>

{

public ApplicationDbContext()

: base("DefaultConnection", throwIfV1Schema: false)

{

}

Copy the above code to the IdentityModels.cs under model folder

Configuring ASP.NET Identity

Next, we need to configure the Identity to use UserManager and UserStore.

Let us create class IdentityConfig.cs under the App_start folder as shown below. Remove the App_start from the namespace.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace ASPNetIdentity

{

}

User Store

User store provides the methods to persist the user, user roles, user claims etc to the database.

The UserStore class must implement the IUserStore interface. The interface is defined in the Microsoft.AspNet.Identity namespace. A peek into interface will show us the following

Interface" >public interface IUserStore<TUser, in TKey> : IDisposable where TUser : class, Microsoft.AspNet.Identity.IUser<TKey>

{

Task CreateAsync(TUser user);

Task DeleteAsync(TUser user);

Task<TUser> FindByIdAsync(TKey userId);

Task<TUser> FindByNameAsync(string userName);

Task UpdateAsync(TUser user);

}

It has defined 5 interfaces, which specifies how to Create a new user, Update an existing user, Delete a user, Find a user by ID and Find a user by username

The user store can also optionally implement the following interfaces

The Microsoft.AspNet.Identity.EntityFramework defines the UserStore class, which is a concrete implementation of the IUserStore

In the constructor of the UserStore, requires us to pass the DBContext, so that it knows how to persist the data

Let us create ApplicationUserStore inheriting from the UserStore<ApplicationUser> as shown below.

using ASPNetIdentity.Models;

using Microsoft.AspNet.Identity.EntityFramework;

using Microsoft.AspNet.Identity;

public class ApplicationUserStore : UserStore<ApplicationUser>

{

public ApplicationUserStore(ApplicationDbContext context): base(context)

{

}

Copy the above code to IdentityConfig.cs under App_start folder

If you don’t want to use Entity Framework for your models or you want to implement your own version of persistence mechanism and then this is where you write your own implementation of the store. All you need to do is Implement the IUserStore Interface. Then pass the class in the constructor of UserManager.

User Manager

The UserManager<TUser> is a concrete class that manages the user. It is defined in the Microsoft.AspNet.Identity namespace. This Class Creates, Updates, and Deletes the Users. It has methods to find a user by ID, User Name and email. It also provides the functionality for adding Claims, removing claims, add and removing roles, etc. It also generates password hash, Validates Users etc.

UserManager<TUser> uses the user store to connect to the database.

UserStore must be passed to the UserManager in its Constructor. You can pass any object that implements IUserStore interface.

User Manager knows nothing about the store. Such a decoupling helps you to write your own version of the persistent mechanism.

We implement our own User manager ApplicationUserManager by deriving it from the UserManager<TUser>. This helps us to extend the functionality at the later stage

In the constructor of the UserManager we pass the user store ( IUserStore<ApplicationUser> ).

public class ApplicationUserManager : UserManager<ApplicationUser>

{

public ApplicationUserManager(IUserStore<ApplicationUser> store): base(store)

{

}

Copy the above code to IdentityConfig.cs under App_start folder

HomeController

We have got the required classes in place. Let us now try to add a user and test it.

We will create a method in HomeController to create a new user. To do that we will create a method called addUser in our controller

Select Controllers folder, right click and click on Add-> Controller. Select MVC5 Controller – Empty Template. Name the Controller as HomeController.

Now, Right click on the Index Action method and click on Add View to add the View. Choose Template as Empty (without model) and check Use a Layout Page.

Add the following code in the Index View

@Html.ActionLink("Add User", "AddUser", "Home")

Open the HomeController and copy paste the following code

public async Task<string> AddUser()

{

ApplicationUser user;

ApplicationUserStore Store = new ApplicationUserStore(new ApplicationDbContext());

ApplicationUserManager userManager = new ApplicationUserManager(Store);

user = new ApplicationUser

{

UserName = "TestUser",

Email = "[email protected]"

};

var result = await userManager.CreateAsync(user);

if (!result.Succeeded)

{

return result.Errors.First();

}

return "User Added";

}

Lets, now look at the code in more detail

First, we have created user variable which will hold the ApplicationUser Instance.

ApplicationUser user;

Next, we have a store variable which holds the instance of ApplicationUserStore. Note that we are passing the ApplicationDbContext to the store so that it knows about the database.

ApplicationUserStore Store = new ApplicationUserStore(new ApplicationDbContext());

Finally, userManager is created by passing the store to it.

ApplicationUserManager userManager = new ApplicationUserManager(Store);

In the Next step, we create a new user

user = new ApplicationUser

{

UserName = "TestUser",

Email = "[email protected]"

};

We, then pass it to userManager.CreateAsync(user). userManager.CreateAsync validates the user for duplication and if everything is ok then it inserts the user into the database. It uses Store Manager, which in turn uses the entity framework to persist the data to the database

var result = await userManager.CreateAsync(user);

The User Manager returns the IdentityResult. The IdentityResult has a property Succeeded which returns a boolean value indicating the success of the operation. It also has Errors Property which returns the list of errors.

if (!result.Succeeded)

{

return result.Errors.First();

}

On successful creation of user, the browser will display the “User Added” message

return "User Added";

Run and Test

Finally, run the application and click on the AddUser link. If everything is fine you should be able to see the “User Added” message.

Identity Tables

Open the database, you will find that the following tables are automatically added by the Identity system

AspNetUsers
Stores Users Information like login name, password etc
AspNetRoles
Stores User Roles
AspNetUserRoles
Associates Particular roles to User
AspNetUserLogins
This table to hold information about 3rd party/external logins like facebook, google etc
AspNetUserClaims
Stores Claims associated with the user

Open the AspNetUsers table and you will see that the user TestUser is added to the table. If you run the application again you will get the error message “Name is already taken.” error message.

The ASP.NET Identity Architecture

Now, let’s recap what we did. The following picture shows how the ASP.NET identity Architecture

Managers

ASP.Net Identity has high-level classes called Managers, which is used by our application to manage Identity models like users, roles, claims etc. Currently, ASP.NET Identity Provides two managers. UserManger andRoleManager

Identity Models

The Identity Models represent the domain model. ASP.NET Identity provides the basic Interface for these models. For Example, IUser Interface for User Model and IRole for Roles, IClaim for Claims.

Use Store

The Managers uses the UseStore to talk to the Stores. The stores define how the users, roles are persisted to the database. The User Manager is decoupled from the UserStore.

This decoupling enables us to create our own implementation of User Store

The ASP.Net Identity brings its own default implementation of Use Store in Using Entity Framework in the namespace Microsoft.AspNet.Identity.EntityFramework. This Framework defines the Concrete implementation of the User Store specific to Entity Framework. It also has concrete classes for Identity Models.

Registering the Users

Now, let us go ahead and complete the User Registration View

RegisterViewModel

Goto Model folder and add the AccountViewModels.cs. Add the following Code

using System;

using System.Collections.Generic;

using System.ComponentModel.DataAnnotations;

using System.Linq;

using System.Web;

namespace ASPNetIdentity.Models

{

public class RegisterViewModel

{

[Required]

[EmailAddress]

[Display(Name = "Email")]

public string Email { get; set; }

[Required]

[StringLength(100, ErrorMessage = "The {0} must be at least {2} characters long.", MinimumLength = 6)]

[DataType(DataType.Password)]

[Display(Name = "Password")]

public string Password { get; set; }

[DataType(DataType.Password)]

[Display(Name = "Confirm password")]

[Compare("Password", ErrorMessage = "The password and confirmation password do not match.")]

public string ConfirmPassword { get; set; }

}

AccountController

Goto Controller folder and add the AccountController.cs

using ASPNetIdentity.Models;

using Microsoft.AspNet.Identity;

using Microsoft.AspNet.Identity.EntityFramework;

using System;

using System.Collections.Generic;

using System.Linq;

using System.Threading.Tasks;

using System.Web;

using System.Web.Mvc;

namespace ASPNetIdentity.Controllers

{

public class AccountController : Controller

{

// GET: /Account/Register

[AllowAnonymous]

public ActionResult Register()

{

return View();

}

// POST: /Account/Register

[HttpPost]

[AllowAnonymous]

[ValidateAntiForgeryToken]

public async Task<ActionResult> Register(RegisterViewModel model)

{

if (ModelState.IsValid)

{

var user = new ApplicationUser { UserName = model.Email, Email = model.Email };

UserStore<ApplicationUser> Store = new UserStore<ApplicationUser>(new ApplicationDbContext());

ApplicationUserManager userManager = new ApplicationUserManager(Store);

var result = await userManager.CreateAsync(user, model.Password);

if (result.Succeeded)

{

return RedirectToAction("Index", "Home");

}

AddErrors(result);

}

// If we got this far, something failed, redisplay form

return View(model);

}

private void AddErrors(IdentityResult result)

{

foreach (var error in result.Errors)

{

ModelState.AddModelError("", error);

}

Register View

Right-click on the Register Action method to create the view. and choose an empty template

@model ASPNetIdentity.Models.RegisterViewModel

ViewBag.Title = "Register";

}

<h2>@ViewBag.Title.</h2>

@using (Html.BeginForm("Register", "Account", FormMethod.Post, new { @class = "form-horizontal", role = "form" }))

{

@Html.AntiForgeryToken()

<h4>Create a new account.</h4>

<hr />

@Html.ValidationSummary("", new { @class = "text-danger" })

@Html.LabelFor(m => m.Email, new { @class = "col-md-2 control-label" })

@Html.TextBoxFor(m => m.Email, new { @class = "form-control" })

</div>

@Html.LabelFor(m => m.Password, new { @class = "col-md-2 control-label" })

@Html.PasswordFor(m => m.Password, new { @class = "form-control" })

</div>

@Html.LabelFor(m => m.ConfirmPassword, new { @class = "col-md-2 control-label" })

@Html.PasswordFor(m => m.ConfirmPassword, new { @class = "form-control" })

</div>

</div>

}

The Layout View

Open the Views -> Shared -> _Layout.cshtml and replace the code with the following code

<!DOCTYPE html>

<html>

<head>

<title>@ViewBag.Title - My ASP.NET Application</title>

</head>

<body>

</button>

@Html.ActionLink("Application name", "Index", "Home", new { area = "" }, new { @class = "navbar-brand" })

</div>

@Html.Partial("_LoginPartial")

</div>

@RenderBody()

<hr />

</footer>

</div>

</body>

</html>

Login View

Open the Views -> Shared folder and create a Partial View _LoginPartial.cshtml and add the code with the following code

@using Microsoft.AspNet.Identity

@if (Request.IsAuthenticated)

{

using (Html.BeginForm("LogOff", "Account", FormMethod.Post, new { id = "logoutForm", @class = "navbar-right" }))

{

@Html.AntiForgeryToken()

<li>

@Html.ActionLink("Hello " + User.Identity.GetUserName() + "!", "Index", "Manage", routeValues: null, htmlAttributes: new { title = "Manage" })

</li>

</ul>

}

else

{

<li>@Html.ActionLink("Register", "Register", "Account", routeValues: null, htmlAttributes: new { id = "registerLink" })</li>

<li>@Html.ActionLink("Log in", "Login", "Account", routeValues: null, htmlAttributes: new { id = "loginLink" })</li>

</ul>

}

That’s it.

Now, you can register users using the application

Conclusion

We learned the basics of ASP.NET Identity system in this tutorial. We Started from scratch and installed required components liked Microsoft.AspNet.Identity.Core, Microsoft.AspNet.Identity.EntityFramework, and Microsoft.AspNet.Identity.Owin.

We then configured our Identity Model, Created User Manager and Stores Manager. Next, We added Add Button and added a user to the database.

Finally, we created Register View to complete the User Registration Process.

In the next, tutorial we will look at how to configure and use the OWIN Authentication middleware.

Here is the link to all the tutorials

Introduction to ASP.NET Identity
ASP.NET Identity Tutorial – Getting Started
ASP.NET Identity Tutorial – OWIN Authentication Middleware
ASP.NET Core Identity

Source Code

郑林

October 19, 2023 at 8:46 pm

非常感谢~Thank you very much,this article explains the profound in simple terms and through a step-by-step way and help me a lot

Yalla Ramana

April 17, 2023 at 3:06 pm

this article is vary nice

sri harsha

August 18, 2022 at 11:01 pm

What an explanation!! Simply superb. This is the only and most detailed tutorial available on internet for OWIN. So thankful to you

June 2, 2022 at 10:59 am

I’ve followed every step but the Identity tables are not being created.
How to create them on an existing database?

Ernest Racheal

July 30, 2020 at 3:17 am

Thanks a whole lot

TekTutorialsHub
July 30, 2020 at 8:13 am
Thanks
1. sufiyan
  May 21, 2021 at 8:29 am
  do you have a video on that topic

July 8, 2020 at 12:03 am

Thank you very much sir!!!

Robin Verma

June 30, 2018 at 7:53 pm

This article is awesome . Great Work , Keep doing this.

df
January 23, 2024 at 7:20 am
d

Sumit

February 5, 2018 at 4:59 pm

Thank You So Much Sir.

peyman

December 4, 2017 at 12:51 pm

my name is peyman this article is very very usefull
thank you very much
Sarvari.P
[email protected]

ASP.NET Identity Tutorial – Getting Started