Identity介绍

Posted 2020-08-15 jqdy

Introduction to Identity?

By Pranav Rastogi, Rick Anderson, Tom Dykstra, Jon Galloway and Erik Reitan

ASP.NET Core Identity is a membership system which allows you to add login functionality to your application. Users can create an account and login with a user name and password or they can use an external login providers such as Facebook, Google, Microsoft Account, Twitter and more.

ASP.NET Core Identity是一个成员系统，允许在应用中添加登陆功能。用户可新建账户并使用用户名和密码登陆，或者使用外部登陆提供者登陆，例如Facebook, Google, Microsoft Account, Twitter等等：

You can configure ASP.NET Core Identity to use a SQL Server database to store user names, passwords, and profile data. Alternatively, you can use your own persistent store to store data in another persistent storage, such as Azure Table Storage.

可配置ASP.NET Core Identity从而使用SQL Server数据库储存用户名、密码和配置信息。或者使用例如Azure Table Storage等其他的存储方式。

Overview of Identity? Identity概述

In this topic, you’ll learn how to use ASP.NET Core Identity to add functionality to register, log in, and log out a user. You can follow along step by step or just read the details. For more detailed instructions about creating apps using ASP.NET Core Identity, see the Next Steps section at the end of this article.

在本文中，你将学习如何使用ASP.NET Core Identity添加功能，实现用户的注册、登陆、注销。你可一步一步地跟着学习，或者仅阅读其中的细节。关于使用ASP.NET Identity更多的细节，请参看本文中的Next Steps中列出的文章。

1. Create an ASP.NET Core Web Application project in Visual Studio with Individual User Accounts. 

In Visual Studio, select File -> New -> Project. Then, select the ASP.NET Web Application from the New Project dialog box. Continue by selecting an ASP.NET Core Web Application with Individual User Accounts as the authentication method.

The created project contains the Microsoft.AspNetCore.Identity.EntityFrameworkCore package, which will persist the identity data and schema to SQL Server using Entity Framework Core.

Note

In Visual Studio, you can view NuGet packages details by selecting Tools -> NuGet Package Manager -> Manage NuGet Packages for Solution. You also see a list of packages in the dependencies section of the project.json file within your project.

在vs中，可通过“Tools -> NuGet Package Manager -> Manage NuGet Packages for Solution”浏览NuGet packages的细节。你也可在项目中的project.json文件中dependencies部分看到引用包的列表

The identity services are added to the application in the ConfigureServices method in the Startup class:

Identity服务被加入到Startup类的ConfigureServices方法中：

// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
    // Add framework services.
    services.AddEntityFramework()
        .AddSqlServer()
        .AddDbContext<ApplicationDbContext>(options =>
            options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]));

    services.AddIdentity<ApplicationUser, IdentityRole>()
        .AddEntityFrameworkStores<ApplicationDbContext>()
        .AddDefaultTokenProviders();

    services.AddMvc();

    // Add application services.
    services.AddTransient<IEmailSender, AuthMessageSender>();
    services.AddTransient<ISmsSender, AuthMessageSender>();

These services are then made available to the application through dependency injection.

通过依赖注入使得应用可以使用这些服务。

Identity is enabled for the application by calling UseIdentity in the Configure method of the Startup class. This adds cookie-based authentication to the request pipeline.

通过调用Startup类的Configure方法中的UserIdentity就可以使用Identity了。这为请求添加了基于cookie的身份验证功能。

    services.Configure<IdentityOptions>(options =>
    {
        // Password settings
        options.Password.RequireDigit = true;
        options.Password.RequiredLength = 8;
        options.Password.RequireNonAlphanumeric = false;
        options.Password.RequireUppercase = true;
        options.Password.RequireLowercase = false;
        
        // Lockout settings
        options.Lockout.DefaultLockoutTimeSpan = TimeSpan.FromMinutes(30);
        options.Lockout.MaxFailedAccessAttempts = 10;
        
        // Cookie settings
        options.Cookies.ApplicationCookie.ExpireTimeSpan = TimeSpan.FromDays(150);
        options.Cookies.ApplicationCookie.LoginPath = "/Account/LogIn";
        options.Cookies.ApplicationCookie.LogoutPath = "/Account/LogOff";
        
        // User settings
        options.User.RequireUniqueEmail = true;
    });
}

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    loggerFactory.AddConsole(Configuration.GetSection("Logging"));
    loggerFactory.AddDebug();

    if (env.IsDevelopment())
    {
        app.UseBrowserLink();

For more information about the application start up process, see Application Startup.

更多关于应用启动过程的信息，请参看Application Startup。

2. Creating a user. 新建用户

Launch the application from Visual Studio (Debug -> Start Debugging) and then click on the Register link in the browser to create a user. The following image shows the Register page which collects the user name and password.

When the user clicks the Register link, the UserManager and SignInManager services are injected into the Controller:

当用户点击Register链接时，UserManager和SignInManager服务被添加到这个控制器中：

    public class AccountController : Controller
    {
        private readonly UserManager<ApplicationUser> _userManager;
        private readonly SignInManager<ApplicationUser> _signInManager;
        private readonly IEmailSender _emailSender;
        private readonly ISmsSender _smsSender;
        private static bool _databaseChecked;
        private readonly ILogger _logger;

        public AccountController(
            UserManager<ApplicationUser> userManager,
            SignInManager<ApplicationUser> signInManager,
            IEmailSender emailSender,
            ISmsSender smsSender,
            ILoggerFactory loggerFactory)
        {
            _userManager = userManager;
            _signInManager = signInManager;
            _emailSender = emailSender;
            _smsSender = smsSender;
            _logger = loggerFactory.CreateLogger<AccountController>();
        }

        //
        // GET: /Account/Login

Then, the Register action creates the user by calling CreateAsync function of the UserManager object, as shown below:

然后，通过调用UserManager类中的CreateAsync函数，Register新建了该用户，如下所示：

[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Register(RegisterViewModel model)
{
    if (ModelState.IsValid)
    {
        var user = new ApplicationUser { UserName = model.Email, Email = model.Email };
        var result = await _userManager.CreateAsync(user, model.Password);
        if (result.Succeeded)
        {
            // For more information on how to enable account confirmation and password reset please visit http://go.microsoft.com/fwlink/?LinkID=532713
            // Send an email with this link
            //var code = await _userManager.GenerateEmailConfirmationTokenAsync(user);
            //var callbackUrl = Url.Action("ConfirmEmail", "Account", new { userId = user.Id, code = code }, protocol: HttpContext.Request.Scheme);
            //await _emailSender.SendEmailAsync(model.Email, "Confirm your account",
            //    "Please confirm your account by clicking this link: <a href=\"" + callbackUrl + "\">link</a>");
            await _signInManager.SignInAsync(user, isPersistent: false);
            _logger.LogInformation(3, "User created a new account with password.");
            return RedirectToAction(nameof(HomeController.Index), "Home");
        }
        AddErrors(result);
    }

    // If we got this far, something failed, redisplay form
    return View(model);
}

 

3. Log in. 登陆

If the user was successfully created, the user is logged in by the SignInAsync method, also contained in the Register action. By signing in, the SignInAsync method stores a cookie with the user’s claims.

如果成功新建了用户，通过SignInAsync方法进行登陆，同样也包含在Register中。通过登陆，SignInAsync方法使用用户声明储存了一个cookie。

[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Register(RegisterViewModel model)
{
    if (ModelState.IsValid)
    {
        var user = new ApplicationUser { UserName = model.Email, Email = model.Email };
        var result = await _userManager.CreateAsync(user, model.Password);
        if (result.Succeeded)
        {
            // For more information on how to enable account confirmation and password reset please visit http://go.microsoft.com/fwlink/?LinkID=532713
            // Send an email with this link
            //var code = await _userManager.GenerateEmailConfirmationTokenAsync(user);
            //var callbackUrl = Url.Action("ConfirmEmail", "Account", new { userId = user.Id, code = code }, protocol: HttpContext.Request.Scheme);
            //await _emailSender.SendEmailAsync(model.Email, "Confirm your account",
            //    "Please confirm your account by clicking this link: <a href=\"" + callbackUrl + "\">link</a>");
            await _signInManager.SignInAsync(user, isPersistent: false);
            _logger.LogInformation(3, "User created a new account with password.");
            return RedirectToAction(nameof(HomeController.Index), "Home");
        }
        AddErrors(result);
    }

    // If we got this far, something failed, redisplay form
    return View(model);
}

The above SignInAsync method calls the below SignInAsync task, which is contained in the SignInManager class.

上面的SignInAsync方法调用下面的SignInAsync任务，该任务包含在SignInManager类中。

If needed, you can access the user’s identity details inside a controller action. For instance, by setting a breakpoint inside the HomeController.Index action method, you can view the User.claims details. By having the user signed-in, you can make authorization decisions. For more information, see Authorization.

如果需要，你可在控制器的方法中使用用户身份的细节信息。比如，在HomeController.Index方法中设置断点，可以浏览User.claims的细节信息。你可搭建授权决策。更多的信息，请参看Authorization。

As a registered user, you can log in to the web app by clicking the Log in link. When a registered user logs in, the Login action of the AccountController is called. Then, the Login action signs in the user using the PasswordSignInAsync method contained in the Login action.

注册用户可以点击Log in链接进行登陆。当注册用户登陆时，调用AccountController的Login方法。然后，Login方法通过其中的PasswordSignInAsync方法实现用户登录。

[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Login(LoginViewModel model, string returnUrl = null)
{
    ViewData["ReturnUrl"] = returnUrl;
    if (ModelState.IsValid)
    {
        // This doesn‘t count login failures towards account lockout
        // To enable password failures to trigger account lockout, set lockoutOnFailure: true
        var result = await _signInManager.PasswordSignInAsync(model.Email, model.Password, model.RememberMe, lockoutOnFailure: false);
        if (result.Succeeded)
        {
            _logger.LogInformation(1, "User logged in.");
            return RedirectToLocal(returnUrl);
        }
        if (result.RequiresTwoFactor)
        {
            return RedirectToAction(nameof(SendCode), new { ReturnUrl = returnUrl, RememberMe = model.RememberMe });
        }
        if (result.IsLockedOut)
        {
            _logger.LogWarning(2, "User account locked out.");
            return View("Lockout");
        }
        else
        {
            ModelState.AddModelError(string.Empty, "Invalid login attempt.");
            return View(model);
        }
    }

    // If we got this far, something failed, redisplay form
    return View(model);
}

 

4. Log off. 登出

Clicking the Log off link calls the LogOff action in the account controller.

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> LogOff()
{
    await _signInManager.SignOutAsync();
    _logger.LogInformation(4, "User logged out.");
    return RedirectToAction(nameof(HomeController.Index), "Home");
}

The code above shows the SignInManager.SignOutAsync method. The SignOutAsync method clears the users claims stored in a cookie.

上面的代码展示了SignInManager.SignOutAsync 方法。SignOutAsync方法清楚了cookie中的用户声明。

5. Configuration. 配置

Identity has some default behaviors that you can override in your application’s startup class.

Identity有一些默认的行为，你可以在应用的startup类中将其重写。

    // Configure Identity
    services.Configure<IdentityOptions>(options =>
    {
        // Password settings
        options.Password.RequireDigit = true;
        options.Password.RequiredLength = 8;
        options.Password.RequireNonAlphanumeric = false;
        options.Password.RequireUppercase = true;
        options.Password.RequireLowercase = false;
        
        // Lockout settings
        options.Lockout.DefaultLockoutTimeSpan = TimeSpan.FromMinutes(30);
        options.Lockout.MaxFailedAccessAttempts = 10;
        
        // Cookie settings
        options.Cookies.ApplicationCookie.ExpireTimeSpan = TimeSpan.FromDays(150);
        options.Cookies.ApplicationCookie.LoginPath = "/Account/LogIn";
        options.Cookies.ApplicationCookie.LogoutPath = "/Account/LogOff";
        
        // User settings
        options.User.RequireUniqueEmail = true;
    });

 

6. View the database.

After stopping the application, view the user database from Visual Studio by selecting View -> SQL Server Object Explorer. Then, expand the following within the SQL Server Object Explorer:

• (localdb)MSSQLLocalDB
• Databases
• aspnet5-<the name of your application>
• Tables

Next, right-click the dbo.AspNetUsers table and select View Data to see the properties of the user you created.

Identity Components?

The primary reference assembly for the identity system is Microsoft.AspNetCore.Identity. This package contains the core set of interfaces for ASP.NET Core Identity.

These dependencies are needed to use the identity system in ASP.NET Core applications:

• EntityFramework.SqlServer - Entity Framework is Microsoft’s recommended data access technology for relational databases.
• Microsoft.AspNetCore.Authentication.Cookies - Middleware that enables an application to use cookie based authentication, similar to ASP.NET’s Forms Authentication.
• Microsoft.AspNetCore.Cryptography.KeyDerivation - Utilities for key derivation.
• Microsoft.AspNetCore.Hosting.Abstractions - Hosting abstractions.

Migrating to ASP.NET Core Identity?

迁移ASP.Net Core Identity

For additional information and guidance on migrating your existing identity store see Migrating Authentication and Identity

Next Steps?

• Migrating Authentication and Identity
• Account Confirmation and Password Recovery
• Two-factor authentication with SMS
• Enabling authentication using Facebook, Google and other external providers