AspNetCore.Docs/aspnetcore/security/authorization/secure-data.md

title	author	description	ms.author	ms.date	ms.custom	uid
Create an ASP.NET Core app with user data protected by authorization	rick-anderson	Learn how to create a Razor Pages app with user data protected by authorization. Includes HTTPS, authentication, security, ASP.NET Core Identity.	riande	12/18/2018	seodec18	security/authorization/secure-data

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

By Rick Anderson and Joe Audette

::: moniker range="<= aspnetcore-1.1"

See this PDF for the ASP.NET Core MVC version. The ASP.NET Core 1.1 version of this tutorial is in this folder. The 1.1 ASP.NET Core sample is in the samples.

::: moniker-end

::: moniker range="= aspnetcore-2.0"

See this pdf

::: moniker-end

::: moniker range=">= aspnetcore-2.1"

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.

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 managers 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 administrators role:

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

The app was created by scaffolding the following Contact model:

[!code-csharp]

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

::: moniker-end

::: moniker range="= aspnetcore-2.1"

In ASP.NET Core 2.1, User.IsInRole fails when using AddDefaultIdentity. This tutorial uses AddDefaultIdentity and therefore requires ASP.NET Core 2.2 or later. See this GitHub issue for a work-around.

::: moniker-end

::: moniker range=">= aspnetcore-2.1"

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.

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:

[!code-csharp]

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:

[!code-csharp]

Require authenticated users

Set the default authentication policy to require users to be authenticated:

[!code-csharp]

You can opt out of authentication at the Razor Page, controller, or action method level with the [AllowAnonymous] attribute. Setting the default authentication policy to require users to be authenticated protects newly added Razor Pages and controllers. Having authentication required by default is more secure than relying on new controllers and Razor Pages to include the [Authorize] attribute.

Add AllowAnonymous to the Index, About, and Contact pages so anonymous users can get information about the site before they register.

[!code-csharp]

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 strong password is not specified, an exception is thrown when SeedData.Initialize is called.

Update Main to use the test password:

[!code-csharp]

Create the test accounts and update the contacts

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

[!code-csharp]

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:

[!code-csharp]

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.

[!code-csharp]

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

• Return context.Succeed when the requirements are met.
• Return Task.CompletedTask when requirements aren't met. Task.CompletedTask is neither success or failure—it allows other authorization handlers to run.

If you need to explicitly fail, return 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).

[!code-csharp]

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.

[!code-csharp]

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:

[!code-csharp]

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:

[!code-csharp]

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:

[!code-csharp]

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:

[!code-csharp]

Update the CreateModel.OnPostAsync method to:

• Add the user ID to the Contact model.
• Call the authorization handler to verify the user has permission to create contacts.

[!code-csharp]

Update the IndexModel

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

[!code-csharp]

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.

[!code-csharp]

Update the DeleteModel

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

[!code-csharp]

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 Views/_ViewImports.cshtml file so it's available to all views:

[!code-cshtml]

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:

[!code-cshtml]

[!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:

[!code-cshtml]

Update the details page model:

[!code-csharp]

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.

Test the completed app

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: Use eight or more characters and at least one upper-case character, number, and symbol. For example, Passw0rd! meets the strong password requirements.

• 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	Seeded by the app	Options
test@example.com	No	Edit/delete the own data.
manager@contoso.com	Yes	Approve/reject and edit/delete own data.
admin@contoso.com	Yes	Approve/reject and edit/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:

  [!code-csharp]

• Scaffold the Contact model.

• Create initial migration and update the database:

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

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

<a asp-page="/Contacts/Index" class="navbar-brand">ContactManager</a>

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

Seed the database

Add the SeedData class to the Data folder.

Call SeedData.Initialize from Main:

[!code-csharp]

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

Additional resources

• Build a .NET Core and SQL Database web app in Azure App Service
• ASP.NET Core Authorization Lab. This lab goes into more detail on the security features introduced in this tutorial.
• xref:security/authorization/introduction
• Custom policy-based authorization

::: moniker-end