Create an ASP.NET Core web app with user data protected by authorization

By Rick Anderson and Joe Audette

This tutorial shows how to create an ASP.NET Core web app with user data protected by authorization. It displays a list of contacts that authenticated (registered) users have created. There are three security groups:

• Registered users can view all the approved data and can edit/delete their own data.
• Managers can approve or reject contact data. Only approved contacts are visible to users.
• Administrators can approve/reject and edit/delete any data.

The images in this document don't exactly match the latest templates.

In the following image, user Rick (rick@example.com) is signed in. Rick can only view approved contacts and Edit/Delete/Create New links for his contacts. Only the last record, created by Rick, displays Edit and Delete links. Other users won't see the last record until a manager or administrator changes the status to "Approved".

In the following image, manager@contoso.com is signed in and in the manager's role:

The following image shows the managers details view of a contact:

The Approve and Reject buttons are only displayed for managers and administrators.

In the following image, admin@contoso.com is signed in and in the administrator's role:

The administrator has all privileges. She can read, edit, or delete any contact and change the status of contacts.

The app was created by scaffolding the following Contact model:

public class Contact
{
    public int ContactId { get; set; }
    public string Name { get; set; }
    public string Address { get; set; }
    public string City { get; set; }
    public string State { get; set; }
    public string Zip { get; set; }
    [DataType(DataType.EmailAddress)]
    public string Email { get; set; }
}

The sample contains the following authorization handlers:

• ContactIsOwnerAuthorizationHandler: Ensures that a user can only edit their data.
• ContactManagerAuthorizationHandler: Allows managers to approve or reject contacts.
• ContactAdministratorsAuthorizationHandler: Allows administrators to approve or reject contacts and to edit/delete contacts.

Prerequisites

This tutorial is advanced. You should be familiar with:

• ASP.NET Core
• Authentication
• Account Confirmation and Password Recovery
• Authorization
• Entity Framework Core

The starter and completed app

Download the completed app. Test the completed app so you become familiar with its security features.

The starter app

Download the starter app.

Run the app, tap the ContactManager link, and verify you can create, edit, and delete a contact. To create the starter app, see Create the starter app.

Secure user data

The following sections have all the major steps to create the secure user data app. You may find it helpful to refer to the completed project.

Tie the contact data to the user

Use the ASP.NET Identity user ID to ensure users can edit their data, but not other users data. Add OwnerID and ContactStatus to the Contact model:

public class Contact
{
    public int ContactId { get; set; }

    // user ID from AspNetUser table.
    public string? OwnerID { get; set; }

    public string? Name { get; set; }
    public string? Address { get; set; }
    public string? City { get; set; }
    public string? State { get; set; }
    public string? Zip { get; set; }
    [DataType(DataType.EmailAddress)]
    public string? Email { get; set; }

    public ContactStatus Status { get; set; }
}

public enum ContactStatus
{
    Submitted,
    Approved,
    Rejected
}

OwnerID is the user's ID from the AspNetUser table in the Identity database. The Status field determines if a contact is viewable by general users.

Create a new migration and update the database:

dotnet ef migrations add userID_Status
dotnet ef database update

Add Role services to Identity

Append AddRoles to add Role services:

var builder = WebApplication.CreateBuilder(args);

var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(connectionString));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddDefaultIdentity<IdentityUser>(
    options => options.SignIn.RequireConfirmedAccount = true)
    .AddRoles<IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDbContext>();

Require authenticated users

Set the fallback authorization policy to require users to be authenticated:

var builder = WebApplication.CreateBuilder(args);

var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(connectionString));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddDefaultIdentity<IdentityUser>(
    options => options.SignIn.RequireConfirmedAccount = true)
    .AddRoles<IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDbContext>();

builder.Services.AddRazorPages();

builder.Services.AddAuthorization(options =>
{
    options.FallbackPolicy = new AuthorizationPolicyBuilder()
        .RequireAuthenticatedUser()
        .Build();
});

The preceding highlighted code sets the fallback authorization policy. The fallback authorization policy requires all users to be authenticated, except for Razor Pages, controllers, or action methods with an authorization attribute. For example, Razor Pages, controllers, or action methods with [AllowAnonymous] or [Authorize(PolicyName="MyPolicy")] use the applied authorization attribute rather than the fallback authorization policy.

RequireAuthenticatedUser adds DenyAnonymousAuthorizationRequirement to the current instance, which enforces that the current user is authenticated.

The fallback authorization policy:

• Is applied to all requests that don't explicitly specify an authorization policy. For requests served by endpoint routing, this includes any endpoint that doesn't specify an authorization attribute. For requests served by other middleware after the authorization middleware, such as static files, this applies the policy to all requests.

Setting the fallback authorization policy to require users to be authenticated protects newly added Razor Pages and controllers. Having authorization required by default is more secure than relying on new controllers and Razor Pages to include the [Authorize] attribute.

The AuthorizationOptions class also contains AuthorizationOptions.DefaultPolicy. The DefaultPolicy is the policy used with the [Authorize] attribute when no policy is specified. [Authorize] doesn't contain a named policy, unlike [Authorize(PolicyName="MyPolicy")].

For more information on policies, see Policy-based authorization in ASP.NET Core.

An alternative way for MVC controllers and Razor Pages to require all users be authenticated is adding an authorization filter:

using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using ContactManager.Data;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc.Authorization;

var builder = WebApplication.CreateBuilder(args);

var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(connectionString));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddDefaultIdentity<IdentityUser>(
    options => options.SignIn.RequireConfirmedAccount = true)
    .AddRoles<IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDbContext>();

builder.Services.AddRazorPages();

builder.Services.AddControllers(config =>
{
    var policy = new AuthorizationPolicyBuilder()
                     .RequireAuthenticatedUser()
                     .Build();
    config.Filters.Add(new AuthorizeFilter(policy));
});

var app = builder.Build();

The preceding code uses an authorization filter, setting the fallback policy uses endpoint routing. Setting the fallback policy is the preferred way to require all users be authenticated.

Add AllowAnonymous to the Index and Privacy pages so anonymous users can get information about the site before they register:

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc.RazorPages;

namespace ContactManager.Pages;

[AllowAnonymous]
public class IndexModel : PageModel
{
    private readonly ILogger<IndexModel> _logger;

    public IndexModel(ILogger<IndexModel> logger)
    {
        _logger = logger;
    }

    public void OnGet()
    {

    }
}

Configure the test account

The SeedData class creates two accounts: administrator and manager. Use the Secret Manager tool to set a password for these accounts. Set the password from the project directory (the directory containing Program.cs):

dotnet user-secrets set SeedUserPW <PW>

If a weak password is specified, an exception is thrown when SeedData.Initialize is called.

Update the app to use the test password:

var builder = WebApplication.CreateBuilder(args);

var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(connectionString));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddDefaultIdentity<IdentityUser>(
    options => options.SignIn.RequireConfirmedAccount = true)
    .AddRoles<IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDbContext>();

builder.Services.AddRazorPages();

builder.Services.AddAuthorization(options =>
{
    options.FallbackPolicy = new AuthorizationPolicyBuilder()
        .RequireAuthenticatedUser()
        .Build();
});

// Authorization handlers.
builder.Services.AddScoped<IAuthorizationHandler,
                      ContactIsOwnerAuthorizationHandler>();

builder.Services.AddSingleton<IAuthorizationHandler,
                      ContactAdministratorsAuthorizationHandler>();

builder.Services.AddSingleton<IAuthorizationHandler,
                      ContactManagerAuthorizationHandler>();

var app = builder.Build();

using (var scope = app.Services.CreateScope())
{
    var services = scope.ServiceProvider;
    var context = services.GetRequiredService<ApplicationDbContext>();
    context.Database.Migrate();
    // requires using Microsoft.Extensions.Configuration;
    // Set password with the Secret Manager tool.
    // dotnet user-secrets set SeedUserPW <pw>

    var testUserPw = builder.Configuration.GetValue<string>("SeedUserPW");

   await SeedData.Initialize(services, testUserPw);
}

Create the test accounts and update the contacts

Update the Initialize method in the SeedData class to create the test accounts:

public static async Task Initialize(IServiceProvider serviceProvider, string testUserPw)
{
    using (var context = new ApplicationDbContext(
        serviceProvider.GetRequiredService<DbContextOptions<ApplicationDbContext>>()))
    {
        // For sample purposes seed both with the same password.
        // Password is set with the following:
        // dotnet user-secrets set SeedUserPW <pw>
        // The admin user can do anything

        var adminID = await EnsureUser(serviceProvider, testUserPw, "admin@contoso.com");
        await EnsureRole(serviceProvider, adminID, Constants.ContactAdministratorsRole);

        // allowed user can create and edit contacts that they create
        var managerID = await EnsureUser(serviceProvider, testUserPw, "manager@contoso.com");
        await EnsureRole(serviceProvider, managerID, Constants.ContactManagersRole);

        SeedDB(context, adminID);
    }
}

private static async Task<string> EnsureUser(IServiceProvider serviceProvider,
                                            string testUserPw, string UserName)
{
    var userManager = serviceProvider.GetService<UserManager<IdentityUser>>();

    var user = await userManager.FindByNameAsync(UserName);
    if (user == null)
    {
        user = new IdentityUser
        {
            UserName = UserName,
            EmailConfirmed = true
        };
        await userManager.CreateAsync(user, testUserPw);
    }

    if (user == null)
    {
        throw new Exception("The password is probably not strong enough!");
    }

    return user.Id;
}

private static async Task<IdentityResult> EnsureRole(IServiceProvider serviceProvider,
                                                              string uid, string role)
{
    var roleManager = serviceProvider.GetService<RoleManager<IdentityRole>>();

    if (roleManager == null)
    {
        throw new Exception("roleManager null");
    }

    IdentityResult IR;
    if (!await roleManager.RoleExistsAsync(role))
    {
        IR = await roleManager.CreateAsync(new IdentityRole(role));
    }

    var userManager = serviceProvider.GetService<UserManager<IdentityUser>>();

    //if (userManager == null)
    //{
    //    throw new Exception("userManager is null");
    //}

    var user = await userManager.FindByIdAsync(uid);

    if (user == null)
    {
        throw new Exception("The testUserPw password was probably not strong enough!");
    }

    IR = await userManager.AddToRoleAsync(user, role);

    return IR;
}

Add the administrator user ID and ContactStatus to the contacts. Make one of the contacts "Submitted" and one "Rejected". Add the user ID and status to all the contacts. Only one contact is shown:

public static void SeedDB(ApplicationDbContext context, string adminID)
{
    if (context.Contact.Any())
    {
        return;   // DB has been seeded
    }

    context.Contact.AddRange(
        new Contact
        {
            Name = "Debra Garcia",
            Address = "1234 Main St",
            City = "Redmond",
            State = "WA",
            Zip = "10999",
            Email = "debra@example.com",
            Status = ContactStatus.Approved,
            OwnerID = adminID
        },

Create owner, manager, and administrator authorization handlers

Create a ContactIsOwnerAuthorizationHandler class in the Authorization folder. The ContactIsOwnerAuthorizationHandler verifies that the user acting on a resource owns the resource.

using ContactManager.Models;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Authorization.Infrastructure;
using Microsoft.AspNetCore.Identity;
using System.Threading.Tasks;

namespace ContactManager.Authorization
{
    public class ContactIsOwnerAuthorizationHandler
                : AuthorizationHandler<OperationAuthorizationRequirement, Contact>
    {
        UserManager<IdentityUser> _userManager;

        public ContactIsOwnerAuthorizationHandler(UserManager<IdentityUser> 
            userManager)
        {
            _userManager = userManager;
        }

        protected override Task
            HandleRequirementAsync(AuthorizationHandlerContext context,
                                   OperationAuthorizationRequirement requirement,
                                   Contact resource)
        {
            if (context.User == null || resource == null)
            {
                return Task.CompletedTask;
            }

            // If not asking for CRUD permission, return.

            if (requirement.Name != Constants.CreateOperationName &&
                requirement.Name != Constants.ReadOperationName   &&
                requirement.Name != Constants.UpdateOperationName &&
                requirement.Name != Constants.DeleteOperationName )
            {
                return Task.CompletedTask;
            }

            if (resource.OwnerID == _userManager.GetUserId(context.User))
            {
                context.Succeed(requirement);
            }

            return Task.CompletedTask;
        }
    }
}

The ContactIsOwnerAuthorizationHandler calls context.Succeed if the current authenticated user is the contact owner. Authorization handlers generally:

• Call context.Succeed when the requirements are met.
• Return Task.CompletedTask when requirements aren't met. Returning Task.CompletedTask without a prior call to context.Success or context.Fail, is not a success or failure, it allows other authorization handlers to run.

If you need to explicitly fail, call context.Fail.

The app allows contact owners to edit/delete/create their own data. ContactIsOwnerAuthorizationHandler doesn't need to check the operation passed in the requirement parameter.

Create a manager authorization handler

Create a ContactManagerAuthorizationHandler class in the Authorization folder. The ContactManagerAuthorizationHandler verifies the user acting on the resource is a manager. Only managers can approve or reject content changes (new or changed).

using System.Threading.Tasks;
using ContactManager.Models;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Authorization.Infrastructure;
using Microsoft.AspNetCore.Identity;

namespace ContactManager.Authorization
{
    public class ContactManagerAuthorizationHandler :
        AuthorizationHandler<OperationAuthorizationRequirement, Contact>
    {
        protected override Task
            HandleRequirementAsync(AuthorizationHandlerContext context,
                                   OperationAuthorizationRequirement requirement,
                                   Contact resource)
        {
            if (context.User == null || resource == null)
            {
                return Task.CompletedTask;
            }

            // If not asking for approval/reject, return.
            if (requirement.Name != Constants.ApproveOperationName &&
                requirement.Name != Constants.RejectOperationName)
            {
                return Task.CompletedTask;
            }

            // Managers can approve or reject.
            if (context.User.IsInRole(Constants.ContactManagersRole))
            {
                context.Succeed(requirement);
            }

            return Task.CompletedTask;
        }
    }
}

Create an administrator authorization handler

Create a ContactAdministratorsAuthorizationHandler class in the Authorization folder. The ContactAdministratorsAuthorizationHandler verifies the user acting on the resource is an administrator. Administrator can do all operations.

using System.Threading.Tasks;
using ContactManager.Models;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Authorization.Infrastructure;

namespace ContactManager.Authorization
{
    public class ContactAdministratorsAuthorizationHandler
                    : AuthorizationHandler<OperationAuthorizationRequirement, Contact>
    {
        protected override Task HandleRequirementAsync(
                                              AuthorizationHandlerContext context,
                                    OperationAuthorizationRequirement requirement, 
                                     Contact resource)
        {
            if (context.User == null)
            {
                return Task.CompletedTask;
            }

            // Administrators can do anything.
            if (context.User.IsInRole(Constants.ContactAdministratorsRole))
            {
                context.Succeed(requirement);
            }

            return Task.CompletedTask;
        }
    }
}

Register the authorization handlers

Services using Entity Framework Core must be registered for dependency injection using AddScoped. The ContactIsOwnerAuthorizationHandler uses ASP.NET Core Identity, which is built on Entity Framework Core. Register the handlers with the service collection so they're available to the ContactsController through dependency injection. Add the following code to the end of ConfigureServices:

var builder = WebApplication.CreateBuilder(args);

var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(connectionString));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddDefaultIdentity<IdentityUser>(
    options => options.SignIn.RequireConfirmedAccount = true)
    .AddRoles<IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDbContext>();

builder.Services.AddRazorPages();

builder.Services.AddAuthorization(options =>
{
    options.FallbackPolicy = new AuthorizationPolicyBuilder()
        .RequireAuthenticatedUser()
        .Build();
});

// Authorization handlers.
builder.Services.AddScoped<IAuthorizationHandler,
                      ContactIsOwnerAuthorizationHandler>();

builder.Services.AddSingleton<IAuthorizationHandler,
                      ContactAdministratorsAuthorizationHandler>();

builder.Services.AddSingleton<IAuthorizationHandler,
                      ContactManagerAuthorizationHandler>();

var app = builder.Build();

using (var scope = app.Services.CreateScope())
{
    var services = scope.ServiceProvider;
    var context = services.GetRequiredService<ApplicationDbContext>();
    context.Database.Migrate();
    // requires using Microsoft.Extensions.Configuration;
    // Set password with the Secret Manager tool.
    // dotnet user-secrets set SeedUserPW <pw>

    var testUserPw = builder.Configuration.GetValue<string>("SeedUserPW");

   await SeedData.Initialize(services, testUserPw);
}

ContactAdministratorsAuthorizationHandler and ContactManagerAuthorizationHandler are added as singletons. They're singletons because they don't use EF and all the information needed is in the Context parameter of the HandleRequirementAsync method.

Support authorization

In this section, you update the Razor Pages and add an operations requirements class.

Review the contact operations requirements class

Review the ContactOperations class. This class contains the requirements the app supports:

using Microsoft.AspNetCore.Authorization.Infrastructure;

namespace ContactManager.Authorization
{
    public static class ContactOperations
    {
        public static OperationAuthorizationRequirement Create =   
          new OperationAuthorizationRequirement {Name=Constants.CreateOperationName};
        public static OperationAuthorizationRequirement Read = 
          new OperationAuthorizationRequirement {Name=Constants.ReadOperationName};  
        public static OperationAuthorizationRequirement Update = 
          new OperationAuthorizationRequirement {Name=Constants.UpdateOperationName}; 
        public static OperationAuthorizationRequirement Delete = 
          new OperationAuthorizationRequirement {Name=Constants.DeleteOperationName};
        public static OperationAuthorizationRequirement Approve = 
          new OperationAuthorizationRequirement {Name=Constants.ApproveOperationName};
        public static OperationAuthorizationRequirement Reject = 
          new OperationAuthorizationRequirement {Name=Constants.RejectOperationName};
    }

    public class Constants
    {
        public static readonly string CreateOperationName = "Create";
        public static readonly string ReadOperationName = "Read";
        public static readonly string UpdateOperationName = "Update";
        public static readonly string DeleteOperationName = "Delete";
        public static readonly string ApproveOperationName = "Approve";
        public static readonly string RejectOperationName = "Reject";

        public static readonly string ContactAdministratorsRole = 
                                                              "ContactAdministrators";
        public static readonly string ContactManagersRole = "ContactManagers";
    }
}

Create a base class for the Contacts Razor Pages

Create a base class that contains the services used in the contacts Razor Pages. The base class puts the initialization code in one location:

using ContactManager.Data;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc.RazorPages;

namespace ContactManager.Pages.Contacts
{
    public class DI_BasePageModel : PageModel
    {
        protected ApplicationDbContext Context { get; }
        protected IAuthorizationService AuthorizationService { get; }
        protected UserManager<IdentityUser> UserManager { get; }

        public DI_BasePageModel(
            ApplicationDbContext context,
            IAuthorizationService authorizationService,
            UserManager<IdentityUser> userManager) : base()
        {
            Context = context;
            UserManager = userManager;
            AuthorizationService = authorizationService;
        } 
    }
}

The preceding code:

• Adds the IAuthorizationService service to access to the authorization handlers.
• Adds the Identity UserManager service.
• Add the ApplicationDbContext.

Update the CreateModel

Update the create page model:

• Constructor to use the DI_BasePageModel base class.
• OnPostAsync method to:
  • Add the user ID to the Contact model.
  • Call the authorization handler to verify the user has permission to create contacts.

using ContactManager.Authorization;
using ContactManager.Data;
using ContactManager.Models;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;

namespace ContactManager.Pages.Contacts
{
    public class CreateModel : DI_BasePageModel
    {
        public CreateModel(
            ApplicationDbContext context,
            IAuthorizationService authorizationService,
            UserManager<IdentityUser> userManager)
            : base(context, authorizationService, userManager)
        {
        }

        public IActionResult OnGet()
        {
            return Page();
        }

        [BindProperty]
        public Contact Contact { get; set; }

        public async Task<IActionResult> OnPostAsync()
        {
            if (!ModelState.IsValid)
            {
                return Page();
            }

            Contact.OwnerID = UserManager.GetUserId(User);

            var isAuthorized = await AuthorizationService.AuthorizeAsync(
                                                        User, Contact,
                                                        ContactOperations.Create);
            if (!isAuthorized.Succeeded)
            {
                return Forbid();
            }

            Context.Contact.Add(Contact);
            await Context.SaveChangesAsync();

            return RedirectToPage("./Index");
        }
    }
}

Update the IndexModel

Update the OnGetAsync method so only approved contacts are shown to general users:

public class IndexModel : DI_BasePageModel
{
    public IndexModel(
        ApplicationDbContext context,
        IAuthorizationService authorizationService,
        UserManager<IdentityUser> userManager)
        : base(context, authorizationService, userManager)
    {
    }

    public IList<Contact> Contact { get; set; }

    public async Task OnGetAsync()
    {
        var contacts = from c in Context.Contact
                       select c;

        var isAuthorized = User.IsInRole(Constants.ContactManagersRole) ||
                           User.IsInRole(Constants.ContactAdministratorsRole);

        var currentUserId = UserManager.GetUserId(User);

        // Only approved contacts are shown UNLESS you're authorized to see them
        // or you are the owner.
        if (!isAuthorized)
        {
            contacts = contacts.Where(c => c.Status == ContactStatus.Approved
                                        || c.OwnerID == currentUserId);
        }

        Contact = await contacts.ToListAsync();
    }
}

Update the EditModel

Add an authorization handler to verify the user owns the contact. Because resource authorization is being validated, the [Authorize] attribute is not enough. The app doesn't have access to the resource when attributes are evaluated. Resource-based authorization must be imperative. Checks must be performed once the app has access to the resource, either by loading it in the page model or by loading it within the handler itself. You frequently access the resource by passing in the resource key.

public class EditModel : DI_BasePageModel
{
    public EditModel(
        ApplicationDbContext context,
        IAuthorizationService authorizationService,
        UserManager<IdentityUser> userManager)
        : base(context, authorizationService, userManager)
    {
    }

    [BindProperty]
    public Contact Contact { get; set; }

    public async Task<IActionResult> OnGetAsync(int id)
    {
        Contact? contact = await Context.Contact.FirstOrDefaultAsync(
                                                         m => m.ContactId == id);
        if (contact == null)
        {
            return NotFound();
        }

        Contact = contact;

        var isAuthorized = await AuthorizationService.AuthorizeAsync(
                                                  User, Contact,
                                                  ContactOperations.Update);
        if (!isAuthorized.Succeeded)
        {
            return Forbid();
        }

        return Page();
    }

    public async Task<IActionResult> OnPostAsync(int id)
    {
        if (!ModelState.IsValid)
        {
            return Page();
        }

        // Fetch Contact from DB to get OwnerID.
        var contact = await Context
            .Contact.AsNoTracking()
            .FirstOrDefaultAsync(m => m.ContactId == id);

        if (contact == null)
        {
            return NotFound();
        }

        var isAuthorized = await AuthorizationService.AuthorizeAsync(
                                                 User, contact,
                                                 ContactOperations.Update);
        if (!isAuthorized.Succeeded)
        {
            return Forbid();
        }

        Contact.OwnerID = contact.OwnerID;

        Context.Attach(Contact).State = EntityState.Modified;

        if (Contact.Status == ContactStatus.Approved)
        {
            // If the contact is updated after approval, 
            // and the user cannot approve,
            // set the status back to submitted so the update can be
            // checked and approved.
            var canApprove = await AuthorizationService.AuthorizeAsync(User,
                                    Contact,
                                    ContactOperations.Approve);

            if (!canApprove.Succeeded)
            {
                Contact.Status = ContactStatus.Submitted;
            }
        }

        await Context.SaveChangesAsync();

        return RedirectToPage("./Index");
    }
}

Update the DeleteModel

Update the delete page model to use the authorization handler to verify the user has delete permission on the contact.

public class DeleteModel : DI_BasePageModel
{
    public DeleteModel(
        ApplicationDbContext context,
        IAuthorizationService authorizationService,
        UserManager<IdentityUser> userManager)
        : base(context, authorizationService, userManager)
    {
    }

    [BindProperty]
    public Contact Contact { get; set; }

    public async Task<IActionResult> OnGetAsync(int id)
    {
        Contact? _contact = await Context.Contact.FirstOrDefaultAsync(
                                             m => m.ContactId == id);

        if (_contact == null)
        {
            return NotFound();
        }
        Contact = _contact;

        var isAuthorized = await AuthorizationService.AuthorizeAsync(
                                                 User, Contact,
                                                 ContactOperations.Delete);
        if (!isAuthorized.Succeeded)
        {
            return Forbid();
        }

        return Page();
    }

    public async Task<IActionResult> OnPostAsync(int id)
    {
        var contact = await Context
            .Contact.AsNoTracking()
            .FirstOrDefaultAsync(m => m.ContactId == id);

        if (contact == null)
        {
            return NotFound();
        }

        var isAuthorized = await AuthorizationService.AuthorizeAsync(
                                                 User, contact,
                                                 ContactOperations.Delete);
        if (!isAuthorized.Succeeded)
        {
            return Forbid();
        }

        Context.Contact.Remove(contact);
        await Context.SaveChangesAsync();

        return RedirectToPage("./Index");
    }
}

Inject the authorization service into the views

Currently, the UI shows edit and delete links for contacts the user can't modify.

Inject the authorization service in the Pages/_ViewImports.cshtml file so it's available to all views:

@using Microsoft.AspNetCore.Identity
@using ContactManager
@using ContactManager.Data
@namespace ContactManager.Pages
@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers
@using ContactManager.Authorization;
@using Microsoft.AspNetCore.Authorization
@using ContactManager.Models
@inject IAuthorizationService AuthorizationService

The preceding markup adds several using statements.

Update the Edit and Delete links in Pages/Contacts/Index.cshtml so they're only rendered for users with the appropriate permissions:

@page
@model ContactManager.Pages.Contacts.IndexModel

@{
    ViewData["Title"] = "Index";
}

<h1>Index</h1>

<p>
    <a asp-page="Create">Create New</a>
</p>
<table class="table">
    <thead>
        <tr>
            <th>
                @Html.DisplayNameFor(model => model.Contact[0].Name)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Contact[0].Address)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Contact[0].City)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Contact[0].State)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Contact[0].Zip)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Contact[0].Email)
            </th>
             <th>
                @Html.DisplayNameFor(model => model.Contact[0].Status)
            </th>
            <th></th>
        </tr>
    </thead>
    <tbody>
@foreach (var item in Model.Contact) {
        <tr>
            <td>
                @Html.DisplayFor(modelItem => item.Name)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Address)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.City)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.State)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Zip)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Email)
            </td>
                           <td>
                    @Html.DisplayFor(modelItem => item.Status)
                </td>
                <td>
                    @if ((await AuthorizationService.AuthorizeAsync(
                     User, item,
                     ContactOperations.Update)).Succeeded)
                    {
                        <a asp-page="./Edit" asp-route-id="@item.ContactId">Edit</a>
                        <text> | </text>
                    }

                    <a asp-page="./Details" asp-route-id="@item.ContactId">Details</a>

                    @if ((await AuthorizationService.AuthorizeAsync(
                     User, item,
                     ContactOperations.Delete)).Succeeded)
                    {
                        <text> | </text>
                        <a asp-page="./Delete" asp-route-id="@item.ContactId">Delete</a>
                    }
                </td>
            </tr>
        }
    </tbody>
</table>

Warning

Hiding links from users that don't have permission to change data doesn't secure the app. Hiding links makes the app more user-friendly by displaying only valid links. Users can hack the generated URLs to invoke edit and delete operations on data they don't own. The Razor Page or controller must enforce access checks to secure the data.

Update Details

Update the details view so managers can approve or reject contacts:

        @*Preceding markup omitted for brevity.*@
        <dt class="col-sm-2">
            @Html.DisplayNameFor(model => model.Contact.Email)
        </dt>
        <dd class="col-sm-10">
            @Html.DisplayFor(model => model.Contact.Email)
        </dd>
    <dt>
            @Html.DisplayNameFor(model => model.Contact.Status)
        </dt>
        <dd>
            @Html.DisplayFor(model => model.Contact.Status)
        </dd>
    </dl>
</div>

@if (Model.Contact.Status != ContactStatus.Approved)
{
    @if ((await AuthorizationService.AuthorizeAsync(
     User, Model.Contact, ContactOperations.Approve)).Succeeded)
    {
        <form style="display:inline;" method="post">
            <input type="hidden" name="id" value="@Model.Contact.ContactId" />
            <input type="hidden" name="status" value="@ContactStatus.Approved" />
            <button type="submit" class="btn btn-xs btn-success">Approve</button>
        </form>
    }
}

@if (Model.Contact.Status != ContactStatus.Rejected)
{
    @if ((await AuthorizationService.AuthorizeAsync(
     User, Model.Contact, ContactOperations.Reject)).Succeeded)
    {
        <form style="display:inline;" method="post">
            <input type="hidden" name="id" value="@Model.Contact.ContactId" />
            <input type="hidden" name="status" value="@ContactStatus.Rejected" />
            <button type="submit" class="btn btn-xs btn-danger">Reject</button>
        </form>
    }
}

<div>
    @if ((await AuthorizationService.AuthorizeAsync(
         User, Model.Contact,
         ContactOperations.Update)).Succeeded)
    {
        <a asp-page="./Edit" asp-route-id="@Model.Contact.ContactId">Edit</a>
        <text> | </text>
    }
    <a asp-page="./Index">Back to List</a>
</div>

Update the details page model

public class DetailsModel : DI_BasePageModel
{
    public DetailsModel(
        ApplicationDbContext context,
        IAuthorizationService authorizationService,
        UserManager<IdentityUser> userManager)
        : base(context, authorizationService, userManager)
    {
    }

    public Contact Contact { get; set; }

    public async Task<IActionResult> OnGetAsync(int id)
    {
        Contact? _contact = await Context.Contact.FirstOrDefaultAsync(m => m.ContactId == id);

        if (_contact == null)
        {
            return NotFound();
        }
        Contact = _contact;

        var isAuthorized = User.IsInRole(Constants.ContactManagersRole) ||
                           User.IsInRole(Constants.ContactAdministratorsRole);

        var currentUserId = UserManager.GetUserId(User);

        if (!isAuthorized
            && currentUserId != Contact.OwnerID
            && Contact.Status != ContactStatus.Approved)
        {
            return Forbid();
        }

        return Page();
    }

    public async Task<IActionResult> OnPostAsync(int id, ContactStatus status)
    {
        var contact = await Context.Contact.FirstOrDefaultAsync(
                                                  m => m.ContactId == id);

        if (contact == null)
        {
            return NotFound();
        }

        var contactOperation = (status == ContactStatus.Approved)
                                                   ? ContactOperations.Approve
                                                   : ContactOperations.Reject;

        var isAuthorized = await AuthorizationService.AuthorizeAsync(User, contact,
                                    contactOperation);
        if (!isAuthorized.Succeeded)
        {
            return Forbid();
        }
        contact.Status = status;
        Context.Contact.Update(contact);
        await Context.SaveChangesAsync();

        return RedirectToPage("./Index");
    }
}

Add or remove a user to a role

See this issue for information on:

• Removing privileges from a user. For example, muting a user in a chat app.
• Adding privileges to a user.

Differences between Challenge and Forbid

This app sets the default policy to require authenticated users. The following code allows anonymous users. Anonymous users are allowed to show the differences between Challenge vs Forbid.

[AllowAnonymous]
public class Details2Model : DI_BasePageModel
{
    public Details2Model(
        ApplicationDbContext context,
        IAuthorizationService authorizationService,
        UserManager<IdentityUser> userManager)
        : base(context, authorizationService, userManager)
    {
    }

    public Contact Contact { get; set; }

    public async Task<IActionResult> OnGetAsync(int id)
    {
        Contact? _contact = await Context.Contact.FirstOrDefaultAsync(m => m.ContactId == id);

        if (_contact == null)
        {
            return NotFound();
        }
        Contact = _contact;

        if (!User.Identity!.IsAuthenticated)
        {
            return Challenge();
        }

        var isAuthorized = User.IsInRole(Constants.ContactManagersRole) ||
                           User.IsInRole(Constants.ContactAdministratorsRole);

        var currentUserId = UserManager.GetUserId(User);

        if (!isAuthorized
            && currentUserId != Contact.OwnerID
            && Contact.Status != ContactStatus.Approved)
        {
            return Forbid();
        }

        return Page();
    }
}

In the preceding code:

• When the user is not authenticated, a ChallengeResult is returned. When a ChallengeResult is returned, the user is redirected to the sign-in page.
• When the user is authenticated, but not authorized, a ForbidResult is returned. When a ForbidResult is returned, the user is redirected to the access denied page.

Test the completed app

Warning

This article uses the Secret Manager tool to store the password for the seeded user accounts. The Secret Manager tool is used to store sensitive data during local development. For information on authentication procedures that can be used when an app is deployed to a test or production environment, see Secure authentication flows.

If you haven't already set a password for seeded user accounts, use the Secret Manager tool to set a password:

• Choose a strong password:

  • At least 12 characters long but 14 or more is better.
  • A combination of uppercase letters, lowercase letters, numbers, and symbols.
  • Not a word that can be found in a dictionary or the name of a person, character, product, or organization.
  • Significantly different from your previous passwords.
  • Easy for you to remember but difficult for others to guess. Consider using a memorable phrase like "6MonkeysRLooking^".

• Execute the following command from the project's folder, where <PW> is the password:

  dotnet user-secrets set SeedUserPW <PW>
  

If the app has contacts:

• Delete all of the records in the Contact table.
• Restart the app to seed the database.

An easy way to test the completed app is to launch three different browsers (or incognito/InPrivate sessions). In one browser, register a new user (for example, test@example.com). Sign in to each browser with a different user. Verify the following operations:

• Registered users can view all of the approved contact data.
• Registered users can edit/delete their own data.
• Managers can approve/reject contact data. The Details view shows Approve and Reject buttons.
• Administrators can approve/reject and edit/delete all data.

User	Approve or reject contacts	Options
test@example.com	No	Edit and delete their data.
manager@contoso.com	Yes	Edit and delete their data.
admin@contoso.com	Yes	Edit and delete all data.

Create a contact in the administrator's browser. Copy the URL for delete and edit from the administrator contact. Paste these links into the test user's browser to verify the test user can't perform these operations.

Create the starter app

• Create a Razor Pages app named "ContactManager"

  • Create the app with Individual User Accounts.
  • Name it "ContactManager" so the namespace matches the namespace used in the sample.
  • -uld specifies LocalDB instead of SQLite

  dotnet new webapp -o ContactManager -au Individual -uld
  

• Add Models/Contact.cs: secure-data\samples\starter6\ContactManager\Models\Contact.cs

  using System.ComponentModel.DataAnnotations;
  
  namespace ContactManager.Models
  {
      public class Contact
      {
          public int ContactId { get; set; }
          public string? Name { get; set; }
          public string? Address { get; set; }
          public string? City { get; set; }
          public string? State { get; set; }
          public string? Zip { get; set; }
          [DataType(DataType.EmailAddress)]
          public string? Email { get; set; }
      }
  }
  

• Scaffold the Contact model.

• Create initial migration and update the database:

dotnet add package Microsoft.VisualStudio.Web.CodeGeneration.Design
dotnet tool install -g dotnet-aspnet-codegenerator
dotnet-aspnet-codegenerator razorpage -m Contact -udl -dc ApplicationDbContext -outDir Pages\Contacts --referenceScriptLibraries
dotnet ef database drop -f
dotnet ef migrations add initial
dotnet ef database update

Note

By default the architecture of the .NET binaries to install represents the currently running OS architecture. To specify a different OS architecture, see dotnet tool install, --arch option. For more information, see GitHub issue dotnet/AspNetCore.Docs #29262.

• Update the ContactManager anchor in the Pages/Shared/_Layout.cshtml file:

  <a class="nav-link text-dark" asp-area="" asp-page="/Contacts/Index">Contact Manager</a>
  

• Test the app by creating, editing, and deleting a contact

Seed the database

Add the SeedData class to the Data folder:

using ContactManager.Models;
using Microsoft.EntityFrameworkCore;

// dotnet aspnet-codegenerator razorpage -m Contact -dc ApplicationDbContext -udl -outDir Pages\Contacts --referenceScriptLibraries

namespace ContactManager.Data
{
    public static class SeedData
    {
        public static async Task Initialize(IServiceProvider serviceProvider, string testUserPw="")
        {
            using (var context = new ApplicationDbContext(
                serviceProvider.GetRequiredService<DbContextOptions<ApplicationDbContext>>()))
            {
                SeedDB(context, testUserPw);
            }
        }

        public static void SeedDB(ApplicationDbContext context, string adminID)
        {
            if (context.Contact.Any())
            {
                return;   // DB has been seeded
            }

            context.Contact.AddRange(
                new Contact
                {
                    Name = "Debra Garcia",
                    Address = "1234 Main St",
                    City = "Redmond",
                    State = "WA",
                    Zip = "10999",
                    Email = "debra@example.com"
                },
                new Contact
                {
                    Name = "Thorsten Weinrich",
                    Address = "5678 1st Ave W",
                    City = "Redmond",
                    State = "WA",
                    Zip = "10999",
                    Email = "thorsten@example.com"
                },
                new Contact
                {
                    Name = "Yuhong Li",
                    Address = "9012 State st",
                    City = "Redmond",
                    State = "WA",
                    Zip = "10999",
                    Email = "yuhong@example.com"
                },
                new Contact
                {
                    Name = "Jon Orton",
                    Address = "3456 Maple St",
                    City = "Redmond",
                    State = "WA",
                    Zip = "10999",
                    Email = "jon@example.com"
                },
                new Contact
                {
                    Name = "Diliana Alexieva-Bosseva",
                    Address = "7890 2nd Ave E",
                    City = "Redmond",
                    State = "WA",
                    Zip = "10999",
                    Email = "diliana@example.com"
                }
             );
            context.SaveChanges();
        }

    }
}

Call SeedData.Initialize from Program.cs:

using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using ContactManager.Data;

var builder = WebApplication.CreateBuilder(args);

var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(connectionString));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
    .AddEntityFrameworkStores<ApplicationDbContext>();
builder.Services.AddRazorPages();

var app = builder.Build();

using (var scope = app.Services.CreateScope())
{
    var services = scope.ServiceProvider;

    await SeedData.Initialize(services);
}

if (app.Environment.IsDevelopment())
{
    app.UseMigrationsEndPoint();
}
else
{
    app.UseExceptionHandler("/Error");
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();

app.UseAuthentication();
app.UseAuthorization();

app.MapRazorPages();

app.Run();

Test that the app seeded the database. If there are any rows in the contact DB, the seed method doesn't run.

Additional resources

• Tutorial: Build an ASP.NET Core and Azure SQL Database app in Azure App Service
• ASP.NET Core Authorization Lab. This lab goes into more detail on the security features introduced in this tutorial.
• Introduction to authorization in ASP.NET Core
• Custom policy-based authorization