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For our new friends:

Logto is an Auth0 alternative designed for modern apps and SaaS products. It offers both Cloud and Open-source services to help you quickly launch your identity and management (IAM) system. Enjoy authentication, authorization, and multi-tenant management all in one.

We recommend starting with a free development tenant on Logto Cloud. This allows you to explore all the features easily.

In this article, we will go through the steps to quickly build the Twilio sign-in experience (user authentication) with .NET Core (Blazor WebAssembly) and Logto.

Prerequisites

Create an application in Logto​

Logto is based on OpenID Connect (OIDC) authentication and OAuth 2.0 authorization. It supports federated identity management across multiple applications, commonly called Single Sign-On (SSO).

To create your Single page app application, simply follow these steps:

  1. Open the Logto Console. In the "Get started" section, click the "View all" link to open the application frameworks list. Alternatively, you can navigate to Logto Console > Applications, and click the "Create application" button. Get started
  2. In the opening modal, click the "Single page app" section or filter all the available "Single page app" frameworks using the quick filter checkboxes on the left. Click the ".NET Core (Blazor WebAssembly)" framework card to start creating your application. Frameworks
  3. Enter the application name, e.g., "Bookstore," and click "Create application".

🎉 Ta-da! You just created your first application in Logto. You'll see a congrats page which includes a detailed integration guide. Follow the guide to see what the experience will be in your application.

Integrate Logto SDK​

tip:

Installation​

Add the NuGet package to your project:

dotnet add package Blorc.OpenIdConnect

Add script references​

Include Blorc.Core/injector.js the index.html file:

index.html
<head>
  <!-- ... -->
  <script src="_content/Blorc.Core/injector.js"></script>
  <!-- ... -->
</head>

Register services​

Add the following code to the Program.cs file:

Program.cs
using Blorc.OpenIdConnect;
using Blorc.Services;

builder.Services.AddBlorcCore();
builder.Services.AddAuthorizationCore();
builder.Services.AddBlorcOpenIdConnect(
    options =>
    {
        builder.Configuration.Bind("IdentityServer", options);
    });

var webAssemblyHost = builder.Build();

await webAssemblyHost
    .ConfigureDocumentAsync(async documentService =>
    {
        await documentService.InjectBlorcCoreJsAsync();
        await documentService.InjectOpenIdConnectAsync();
    });

await webAssemblyHost.RunAsync();
info:

There's no need to use the Microsoft.AspNetCore.Components.WebAssembly.Authentication package. The Blorc.OpenIdConnect package will take care of the authentication process.

Configure redirect URIs​

Before we dive into the details, here's a quick overview of the end-user experience. The sign-in process can be simplified as follows:

  1. Your app invokes the sign-in method.
  2. The user is redirected to the Logto sign-in page. For native apps, the system browser is opened.
  3. The user signs in and is redirected back to your app (configured as the redirect URI).

Regarding redirect-based sign-in​

  1. This authentication process follows the OpenID Connect (OIDC) protocol, and Logto enforces strict security measures to protect user sign-in.
  2. If you have multiple apps, you can use the same identity provider (Logto). Once the user signs in to one app, Logto will automatically complete the sign-in process when the user accesses another app.

To learn more about the rationale and benefits of redirect-based sign-in, see Logto sign-in experience explained.

note:

In the following code snippets, we assume your app is running on http://localhost:3000/.

Configure redirect URIs​

Switch to the application details page of Logto Console. Add a redirect URI http://localhost:3000/callback.

Redirect URI in Logto Console

Just like signing in, users should be redirected to Logto for signing out of the shared session. Once finished, it would be great to redirect the user back to your website. For example, add http://localhost:3000/ as the post sign-out redirect URI section.

Then click "Save" to save the changes.

Configure application​

Add the following code to the appsettings.json file:

appsettings.json
{
// ...
IdentityServer: {
  Authority: 'https://<your-logto-endpoint>/oidc',
  ClientId: '<your-logto-app-id>',
  PostLogoutRedirectUri: 'http://localhost:3000/',
  RedirectUri: 'http://localhost:3000/callback',
  ResponseType: 'code',
  Scope: 'openid profile', // Add more scopes if needed
},
}

Remember to add the RedirectUri and PostLogoutRedirectUri to the list of allowed redirect URIs in the Logto application settings. They are both the URL of your WASM application.

Add AuthorizeView component​

In the Razor pages that require authentication, add the AuthorizeView component. Let's assume it's the Home.razor page:

Pages/Home.razor
@using Microsoft.AspNetCore.Components.Authorization
@page "/"

<AuthorizeView>
    <Authorized>
        @* Signed in view *@
        <button @onclick="OnLogoutButtonClickAsync">
            Sign out
        </button>
    </Authorized>
    <NotAuthorized>
        @* Unauthenticated view *@
        <button @onclick="OnLoginButtonClickAsync">
            Sign in
        </button>
    </NotAuthorized>
</AuthorizeView>

Set up authentication​

In the Home.razor.cs file (create it if it doesn't exist), add the following code:

Pages/Home.razor.cs
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Components;
using Microsoft.AspNetCore.Components.Web;
using Blorc.OpenIdConnect;
using Microsoft.AspNetCore.Components.Authorization;

[Authorize]
public partial class Home : ComponentBase
{
    [Inject]
    public required IUserManager UserManager { get; set; }

    public User<Profile>? User { get; set; }

    [CascadingParameter]
    protected Task<AuthenticationState>? AuthenticationStateTask { get; set; }

    protected override async Task OnInitializedAsync()
    {
        User = await UserManager.GetUserAsync<User<Profile>>(AuthenticationStateTask!);
    }

    private async Task OnLoginButtonClickAsync(MouseEventArgs obj)
    {
        await UserManager.SignInRedirectAsync();
    }

    private async Task OnLogoutButtonClickAsync(MouseEventArgs obj)
    {
        await UserManager.SignOutRedirectAsync();
    }
}

Once the user is authenticated, the User property will be populated with the user information.

Checkpoint: Test your application​

Now, you can test your application:

  1. Run your application, you will see the sign-in button.
  2. Click the sign-in button, the SDK will init the sign-in process and redirect you to the Logto sign-in page.
  3. After you signed in, you will be redirected back to your application and see the sign-out button.
  4. Click the sign-out button to clear token storage and sign out.

Add Twilio connector​

SMS connector is a method used to send one-time passwords (OTPs) for authentication. It enables Phone number verification to support passwordless authentication, including SMS-based registration, sign-in, two-factor authentication (2FA), and account recovery. You can easily connect Twilio as your SMS provider. With the Logto SMS connector, you can set this up in just a few minutes.

To add a SMS connector, simply follow these steps:

  1. Navigate to Console > Connector > Email and SMS connectors.
  2. To add a new SMS connector, click the "Set up" button and select "Twilio".
  3. Review the README documentation for your selected provider.
  4. Complete the configuration fields in the "Parameter Configuration" section.
  5. Customize the SMS template using the JSON editor.
  6. Test your configuration by sending a verification code to your Phone number.

Connector tab

note:

If you are following the in-place Connector guide, you can skip the next section.

Set up Twilio SMS connector​

Register Twilio account​

Create a new account on Twilio. (Jump to the next step if you already have one.)

Set up senders' phone numbers​

Go to the Twilio console page and sign in with your Twilio account.

Purchase a phone number under "Phone Numbers" -> "Manage" -> "Buy a number".

tip:

Sometimes you may encounter the situation that SMS service is not supported in specific countries or areas. Pick a number from other regions to bypass.

Once we have a valid number claimed, nav to the "Messaging" -> "Services". Create a new Message Service by clicking on the button.

Give a friendly service name and choose Notify my users as our service purpose. Following the next step, choose Phone Number as Sender Type, and add the phone number we just claimed to this service as a sender.

note:

Each phone number can only be linked with one messaging service.

Get account credentials​

We will need the API credentials to make the connector work. Let's begin from the Twilio console page.

Click on the "Account" menu in the top-right corner, then go to the "API keys & tokens" page to get your Account SID and Auth token.

Back to "Messaging" -> "Services" settings page starting from the sidebar, and find the Sid of your service.

Compose the connector JSON​

Fill out the accountSID, authToken and fromMessagingServiceSID fields with Account SID, Auth token and Sid of the corresponding messaging service.

You can add multiple SMS connector templates for different cases. Here is an example of adding a single template:

  • Fill out the content field with arbitrary string-typed contents. Do not forget to leave {{code}} placeholder for random verification code.
  • Fill out the usageType field with either Register, SignIn, ForgotPassword, Generic for different use cases. In order to enable full user flows, templates with usageType Register, SignIn, ForgotPassword and Generic are required.

Test Twilio SMS connector​

You can enter a phone number and click on "Send" to see whether the settings can work before "Save and Done".

That's it. Don't forget to Enable connector in sign-in experience.

Config types​

NameType
accountSIDstring
authTokenstring
fromMessagingServiceSIDstring
templatesTemplates[]
Template PropertiesTypeEnum values
contentstringN/A
usageTypeenum string'Register' | 'SignIn' | 'ForgotPassword' | 'Generic'

Save your configuration​

Double check you have filled out necessary values in the Logto connector configuration area. Click "Save and Done" (or "Save changes") and the Twilio connector should be available now.

Enable Twilio connector in Sign-in Experience​

Once you create a connector successfully, you can enable phone number-based passwordless login and registration.

  1. Navigate to Console > Sign-in experience > Sign-up and sign-in.
  2. Set up sign-up methods (Optional):
    1. Select "Phone number" or "Email or phone number" as the sign-up identifier.
    2. "Verify at sign-up" is forced to be enabled. You can also enable "Create a password" on registration.
  3. Set up sign-in methods:
    1. Select Phone number as one of sign-in identifiers. You can provide multiple available identifiers (email, phone number, and username).
    2. Select "Verification code" and / or "Password" as the authentication factor.
  4. Click "Save changes" and test it in "Live preview".

Sign-in Experience tab

In addition to registration and login via OTPs, you can also have password recovery and -based security verification enabled, as well as linking Phone number to profile. See End-user flows for more details.

Testing and Validation​

Return to your .NET Core (Blazor WebAssembly) app. You should now be able to sign in with Twilio. Enjoy!

Further readings​

End-user flows: Logto provides a out-of-the-box authentication flows including MFA and enterprise SSO, along with powerful APIs for flexible implementation of account settings, security verification, and multi-tenant experience.

Authorization: Authorization defines the actions a user can do or resources they can access after being authenticated. Explore how to protect your API for native and single-page applications and implement Role-based Access Control (RBAC).

Organizations: Particularly effective in multi-tenant SaaS and B2B apps, the organization feature enable tenant creation, member management, organization-level RBAC, and just-in-time-provisioning.

Customer IAM series Our serial blog posts about Customer (or Consumer) Identity and Access Management, from 101 to advanced topics and beyond.