Every app needs authentication and authorization. Logto is an Auth0 alternative designed for modern apps and SaaS products.
In this article, we will go through the steps to quickly build the Twilio sign-in experience (user authentication) with .NET Core (Blazor Server) and Logto.
Prerequisites
- A running Logto instance. Check out the get started page if you don't have one.
- Basic knowledge of .NET Core (Blazor Server).
- A usable Twilio account.
Create an application in Logto
In you browser, open a new tab and enter the link of Logto Admin Console.
Once the page is loaded, in the "Get Started" section click the View all
link to open the application framework list page.
Choose your application type
In the opening modal, scroll to the "Traditional web" section or filter all the available " Traditional web" frameworks using the quick filter checkboxes on the left.
Click the ".NET Core (Blazor Server)" framework card to start creating your application.
Enter application name
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
- The following demonstration is built on .NET Core 8.0. The SDK is compatible with .NET 6.0 or higher.
- The .NET Core sample projects are available in the GitHub repository.
Installation
Add the NuGet package to your project:
dotnet add package Logto.AspNetCore.Authentication
Add Logto authentication
Open Startup.cs
(or Program.cs
) and add the following code to register Logto authentication services:
using Logto.AspNetCore.Authentication;
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddLogtoAuthentication(options =>
{
options.Endpoint = builder.Configuration["Logto:Endpoint"]!;
options.AppId = builder.Configuration["Logto:AppId"]!;
options.AppSecret = builder.Configuration["Logto:AppSecret"];
});
The AddLogtoAuthentication
method will do the following things:
- Set the default authentication scheme to
LogtoDefaults.CookieScheme
. - Set the default challenge scheme to
LogtoDefaults.AuthenticationScheme
. - Set the default sign-out scheme to
LogtoDefaults.AuthenticationScheme
. - Add cookie and OpenID Connect authentication handlers to the authentication scheme.
Add sign-in redirect URI
Add the following URI to the Redirect URIs
list in the Logto application details page:
http://<your-web-app-uri>/Callback
Note this is different from the redirect URI we'll use later in AuthenticationProperties
:
// Just for reference, we will demonstrate how to use it later
new AuthenticationProperties
{
RedirectUri = "/"
};
The RedirectUri
property is used to redirect the user back to your web application after authentication. Note it is different from the redirect URI you configured in the Logto application details page:
- The redirect URI in the Logto application details page is the URI that Logto will redirect the user back to after the user has signed in.
- The
RedirectUri
property is the URI that will be redirected to after necessary actions have been taken in the Logto authentication middleware.
The order of the actions is 1 -> 2. For clarity, let's call the redirect URI in the Logto application details page the Logto redirect URI and the RedirectUri
property the application redirect URI.
The Logto redirect URI has a default value of /Callback
, which you can leave it as is if there's no special requirement. If you want to change it, you can set the CallbackPath
property for LogtoOptions
:
builder.Services.AddLogtoAuthentication(options =>
{
// Other configurations...
options.CallbackPath = "/SomeOtherCallbackPath";
});
Remember to update the value in the Logto application details page accordingly.
No need to set the application redirect URI in the Logto application details page.
Add sign-out redirect URI
Add the following URI to the Post sign-out redirect URIs
list in the Logto application details page:
http://<your-web-app-uri>/SignedOutCallback
Note this is different from the redirect URI we'll use later in AuthenticationProperties
:
// Just for reference, we will demonstrate how to use it later
new AuthenticationProperties
{
RedirectUri = "/"
};
The RedirectUri
property is used to redirect the user back to your web application after sign-out. Note it is different from the post sign-out redirect URI you configured in the Logto application details page:
- The post sign-out redirect URI in the Logto application details page is the URI that Logto will redirect the user back to after the user has signed out.
- The
RedirectUri
property is the URI that will be redirected to after necessary actions have been taken in the Logto authentication middleware.
The order of the actions is 1 -> 2. For clarity, let's call the post sign-out redirect URI in the Logto application details page the Logto post sign-out redirect URI and the RedirectUri
property the application post sign-out redirect URI.
The Logto post sign-out redirect URI has a default value of /SignedOutCallback
, which you can leave it as is if there's no special requirement. If you want to change it, you can set the SignedOutCallbackPath
property for LogtoOptions
:
builder.Services.AddLogtoAuthentication(options =>
{
// Other configurations...
options.SignedOutCallbackPath = "/SomeOtherSignedOutCallbackPath";
});
Remember to update the value in the Logto application details page accordingly.
No need to set the application post sign-out redirect URI in the Logto application details page.
Add routes
Since Blazor Server uses SignalR to communicate between the server and the client, this means methods that directly manipulate the HTTP context (like issuing challenges or redirects) don't work as expected when called from a Blazor component.
To make it right, we need to explicitly add two endpoints for sign-in and sign-out redirects:
app.MapGet("/SignIn", async context =>
{
if (!(context.User?.Identity?.IsAuthenticated ?? false))
{
await context.ChallengeAsync(new AuthenticationProperties { RedirectUri = "/" });
} else {
context.Response.Redirect("/");
}
});
app.MapGet("/SignOut", async context =>
{
if (context.User?.Identity?.IsAuthenticated ?? false)
{
await context.SignOutAsync(new AuthenticationProperties { RedirectUri = "/" });
} else {
context.Response.Redirect("/");
}
});
Now we can redirect to these endpoints to trigger sign-in and sign-out.
Implement sign-in/sign-out buttons
In the Razor component, add the following code:
@using Microsoft.AspNetCore.Components.Authorization
@using System.Security.Claims
@inject AuthenticationStateProvider AuthenticationStateProvider
@inject NavigationManager NavigationManager
@* ... *@
<p>Is authenticated: @User.Identity?.IsAuthenticated</p>
@if (User.Identity?.IsAuthenticated == true)
{
<button @onclick="SignOut">Sign out</button>
}
else
{
<button @onclick="SignIn">Sign in</button>
}
@* ... *@
@code {
private ClaimsPrincipal? User { get; set; }
protected override async Task OnInitializedAsync()
{
var authState = await AuthenticationStateProvider.GetAuthenticationStateAsync();
User = authState.User;
}
private void SignIn()
{
NavigationManager.NavigateTo("/SignIn", forceLoad: true);
}
private void SignOut()
{
NavigationManager.NavigateTo("/SignOut", forceLoad: true);
}
}
Explanation:
- The injected
AuthenticationStateProvider
is used to get the current user's authentication state, and populate theUser
property. - The
SignIn
andSignOut
methods are used to redirect the user to the sign-in and sign-out endpoints respectively. Since the nature of Blazor Server, we need to useNavigationManager
with force load to trigger the redirection.
The page will show the "Sign in" button if the user is not authenticated, and show the "Sign out" button if the user is authenticated.
The <AuthorizeView />
component
Alternatively, you can use the AuthorizeView
component to conditionally render content based on the user's authentication state. This component is useful when you want to show different content to authenticated and unauthenticated users.
In your Razor component, add the following code:
@using Microsoft.AspNetCore.Components.Authorization
@* ... *@
<AuthorizeView>
<Authorized>
<p>Name: @User?.Identity?.Name</p>
@* Content for authenticated users *@
</Authorized>
<NotAuthorized>
@* Content for unauthenticated users *@
</NotAuthorized>
</AuthorizeView>
@* ... *@
The AuthorizeView
component requires a cascading parameter of type Task<AuthenticationState>
. A direct way to get this parameter is to add the <CascadingAuthenticationState>
component. However, due to the nature of Blazor Server, we cannot simply add the component to the layout or the root component (it may not work as expected). Instead, we can add the following code to the builder (Program.cs
or Startup.cs
) to provide the cascading parameter:
builder.Services.AddCascadingAuthenticationState();
Then you can use the AuthorizeView
component in every component that needs it.
Open your .NET Core (Blazor Server) app to test if the integration works. When you click the "Sign In" button, the page should be redirected to a Logto sign-in page, and you should be able to create a new account by entering username and password and complete the sign-in process.
Add Twilio connector
To add or change SMS connector, go to the "Connector" tab in the Admin Console, then click on "Email and SMS connectors". From there, click "Set up" or go to detail page and click "Change SMS connector".
In the openning modal, select "Twilio" and click "Next".
On the next page, you will see a two-column layout with the README content on the left and configuration on the right.
Feel free to follow the README file in place or read the following section to complete the configuration process. If you follow the in-place 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".
ℹ️ 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, navigate 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.
ℹ️ 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 with 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 eitherRegister
,SignIn
,ForgotPassword
,Generic
for different use cases. In order to enable full user flows, templates with usageTypeRegister
,SignIn
,ForgotPassword
andGeneric
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
Name | Type |
---|---|
accountSID | string |
authToken | string |
fromMessagingServiceSID | string |
templates | Templates[] |
Template Properties | Type | Enum values |
---|---|---|
content | string | N/A |
usageType | enum string | 'Register' | 'SignIn' | 'ForgotPassword' | 'Generic' |
Reference
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
Switch to the "Sign-in experience" tab, then click the "Sign-up and sign-in" tab.
If it's the first time you enter the tab, you will see a quick introduction about Sign-in Experience and its basic configuration.
Select "Phone number" or "Email address or phone number" for the "Sign-up identifier" to provide sign-up for SMS passwordless sign-in, which may increase your conversion rate.
Finally, click "Save changes" on the bottom right corner.
Testing and Validation
Return to your .NET Core (Blazor Server) app. You should now be able to sign in with Twilio. Enjoy!
Further readings
⚔️ Protect your API For native and single page apps, you'll need to call one or more API endpoints to retrieve and update data.
Learn more about identifying who's who and keeping your API secure.
🧑🚀 Manage users We know you care about user management and activities, as we also do.
Learn more about how to know your users and see the figures like DAU and MAU graphically.
🌐 Localization From one regional business to a global corporate, the willingness to offer the best user experience won't change.
You can change current language phrases or add a new language without friction.
🧑🎓 Customer IAM series Our serial blog posts about Customer (or Consumer) Identity and Access Management, from 101 to advanced topics and beyond.